CN112179167A

CN112179167A - Three-fluid heat exchanger capable of controlling heat exchange of heat exchange tubes according to pressure difference

Info

Publication number: CN112179167A
Application number: CN202010145215.8A
Authority: CN
Inventors: 宋文哲; 衣秋杰; 王逸隆; 郭春声; 冷学历
Original assignee: Qingdao Baorun Technology Co ltd
Current assignee: Shenzhen Yiku Technology Co ltd
Priority date: 2020-03-05
Filing date: 2020-03-05
Publication date: 2021-01-05
Anticipated expiration: 2040-03-05
Also published as: CN112179167B

Abstract

The invention provides a three-fluid heat exchanger for controlling heat exchange pipes to heat according to pressure, wherein shell side fluid is a cold source, first fluid and second fluid are heat sources, a left pipe box and a right pipe box are respectively internally provided with a first pressure sensor and a second pressure sensor for detecting the pressure in the left pipe box and the right pipe box, the first pressure sensor and the second pressure sensor are in data connection with a controller, the controller extracts the detected pressure data of the left pipe box and the right pipe box according to time sequence, the pressure difference or the accumulation of the pressure difference change is obtained through the comparison of the pressure data of adjacent time periods, and the opening and closing of a first valve and a second valve are controlled according to the accumulation of the pressure difference or the pressure difference change, so that whether the heat exchange fluids of the first heat exchange pipe and the second heat exchange pipe pass through the heat exchange is controlled. The invention designs a novel heat exchanger with three fluids, and the novel heat exchange tubes are started to alternately exchange heat by detecting the pressure difference or accumulated pressure difference change in the left channel and the right channel, so that the heat exchange effect and the descaling effect are improved.

Description

Three-fluid heat exchanger capable of controlling heat exchange of heat exchange tubes according to pressure difference

Technical Field

The invention relates to a shell-and-tube heat exchanger, in particular to a three-fluid shell-and-tube heat exchanger.

Background

The invention relates to a project which is developed by cooperating with Qingdao science and technology university and relates to descaling of a heat exchanger, and the project is a novel invention which is applied to a shell-and-tube heat exchanger on the basis of the development of the Qingdao science and technology university (application number 2019101874848).

The shell-and-tube heat exchanger is widely applied to industries such as chemical industry, petroleum industry, refrigeration industry, nuclear energy industry and power industry, and due to the worldwide energy crisis, the demand of the heat exchanger in industrial production is more and more, and the quality requirement of the heat exchanger is higher and more. In recent decades, although compact heat exchangers (plate type, plate fin type, pressure welded plate type, etc.), heat pipe type heat exchangers, direct contact type heat exchangers, etc. have been rapidly developed, because the shell and tube type heat exchangers have high reliability and wide adaptability, they still occupy the domination of yield and usage, and according to relevant statistics, the usage of the shell and tube type heat exchangers in the current industrial devices still accounts for about 70% of the usage of all heat exchangers.

After the shell-and-tube heat exchanger is scaled, the heat exchanger is cleaned by adopting conventional modes of steam cleaning, back flushing and the like, and the production practice proves that the effect is not good. The end socket of the heat exchanger can only be disassembled, and a physical cleaning mode is adopted, but the mode is adopted for cleaning, so that the operation is complex, the consumed time is long, the investment of manpower and material resources is large, and great difficulty is brought to continuous industrial production.

The mode of passively strengthening heat exchange is to strictly prevent the fluid vibration induction in the heat exchanger from being changed into effective utilization of vibration, so that the convective heat transfer coefficient of the transmission element at low flow speed is greatly improved, dirt on the surface of the heat transfer element is restrained by vibration, the thermal resistance of the dirt is reduced, and the composite strengthened heat transfer is realized.

In application, it is found that continuous heat exchange can cause the internal fluid to form stability, i.e. the fluid does not flow or has little fluidity, or the flow is stable, so that the vibration performance of the heat exchange tube is greatly weakened, and therefore, the descaling of the heat exchange tube and the heat exchange efficiency are influenced. There is therefore a need for improvements to the above-described heat exchangers.

The heat exchanger generally carries out the heat transfer for two kinds of fluids, but to three kinds of fluid heat transfer but few research, this application has carried out the research to three-fluid heat transfer, has developed new induced vibrations three-fluid shell and tube heat exchanger.

In the prior application, a three-fluid shell-and-tube heat exchanger has been developed, but the shell-and-tube heat exchanger is controlled according to the period, so that the vibration heat exchange effect is poor, and the intelligent degree is lower. The present application therefore provides further improvements over the previous studies.

Disclosure of Invention

The invention provides a three-fluid shell-and-tube heat exchanger with a novel structure aiming at the defects of the shell-and-tube heat exchanger in the prior art. The shell-and-tube heat exchanger can realize heat exchange of three fluids, and the periodic frequent vibration of the heat exchange tubes improves the heat exchange efficiency, thereby realizing good descaling and heat exchange effects.

In order to achieve the purpose, the invention adopts the following technical scheme:

a three-fluid heat exchanger capable of controlling heating of a heat exchange tube according to pressure difference comprises a shell, a heat exchange component, a shell side inlet connecting tube and a shell side outlet connecting tube; the heat exchange component is arranged in the shell and fixedly connected to the front tube plate and the rear tube plate; the shell pass inlet connecting pipe and the shell pass outlet connecting pipe are both arranged on the shell; fluid enters from a shell pass inlet connecting pipe, exchanges heat through a heat exchange component and exits from a shell pass outlet connecting pipe; the heat exchange component comprises a right tube box, a left tube box and a heat exchange tube, the heat exchange tube is communicated with the right tube box and the left tube box, the left tube box and/or the right tube box are/is filled with phase-change fluid, and the phase-change fluid is subjected to closed circulation in the right tube box, the left tube box and the heat exchange tube; the heat exchange tubes are one or more, each heat exchange tube comprises a plurality of arc-shaped tube bundles, the central lines of the arc-shaped tube bundles are arcs with the lower tube boxes as concentric circles, and the end parts of the adjacent tube bundles are communicated, so that the end parts of the tube bundles form tube bundle free ends; the heat exchanger comprises a first heat exchange tube and a second heat exchange tube, the first heat exchange tube penetrates through the left tube box, and the second heat exchange tube penetrates through the right tube box; the first heat exchange tube and the second heat exchange tube respectively flow through a first fluid and a second fluid, and heat exchange of three fluids can be carried out among the first fluid, the second fluid and a shell-side fluid;

the heat exchanger is characterized in that shell side fluid is a cold source, first fluid and second fluid are heat sources, a first pressure sensor and a second pressure sensor are respectively arranged in a left channel box and a right channel box and used for detecting the pressure in the left channel box and the right channel box, the first pressure sensor and the second pressure sensor are in data connection with a controller, the controller extracts the detected pressure data of the left channel box and the right channel box according to a time sequence, the pressure difference or the accumulation of the pressure difference change is obtained through the comparison of the pressure data of adjacent time periods, the opening and closing of a first valve and a second valve are controlled according to the pressure difference or the accumulation of the pressure difference change, and therefore whether the heat exchange fluid of a first heat exchange tube and a second heat exchange tube passes through the heat exchange is controlled.

Preferably, when the first valve is opened and the second valve is closed, the first heat exchange pipe performs heat exchange, and when the second heat exchange pipe does not perform heat exchange, if the pressure of the left pipe box in the previous time period is P1 and the pressure of the left pipe box in the next time period is P2, if the difference between P2 and P1 is lower than the threshold value, the controller closes the first valve, opens the second valve, does not perform heat exchange, and performs heat exchange in the second heat exchange pipe.

Preferably, when the first valve is closed and the second valve is opened, the first heat exchange pipe does not exchange heat, and when the second heat exchange pipe exchanges heat, if the pressure of the right pipe box in the previous time period is P1 and the pressure of the right pipe box in the next time period is P2, if the difference between P2 and P1 is lower than the threshold value, the controller opens the first valve, closes the second valve, the first heat exchange pipe exchanges heat, and the second heat exchange pipe does not exchange heat.

Preferably, the shell is circular in cross section, the heat exchange components are multiple, one of the heat exchange components is arranged in the center of the shell and becomes a central heat exchange component, the other heat exchange components are distributed around the center of the shell and become peripheral heat exchange components, and the heat exchange power of the single peripheral heat exchange component is smaller than that of the central heat exchange component.

Preferably, the pipe diameter of the right pipe box is equal to that of the left pipe box.

Preferably, a return pipe is provided between the right and left tank.

Preferably, the right tube box and the left tube box are arranged along the horizontal direction, the heat exchange tubes are arranged in a plurality along the flowing direction of the fluid in the shell pass, and the tube diameter of the heat exchange tube bundle is continuously increased along the flowing direction of the fluid in the shell pass.

Preferably, the radius of the inner wall of the shell is R, the center of the central heat exchange component is arranged at the center of the circular cross section of the shell, the distance from the center of the right tube box of the peripheral heat exchange component to the center of the circular cross section of the shell is S, the centers of the right tube boxes of the adjacent peripheral heat exchange components are respectively connected with the center of the circular cross section, an included angle formed by the two connecting lines is a, the unit time flow rate of the first fluid of the peripheral heat exchange component is V2, the inlet temperature is T2, the specific heat is C2, the unit time flow rate of the first fluid of a single central heat exchange component is V1, the inlet temperature is T1, and the specific heat is C1, so:

[V2*C2*(T2-T_{standard of merit})]/[V1*C1*(T1-T_{Standard of merit})]A-b Ln (R/S); ln is a logarithmic function; t is_{Standard of merit}The target temperature of the shell-side fluid after heat exchange is set according to the requirement;

a, b are coefficients, wherein 2.0869< a <2.0875,0.6833< b < 0.6837;

preferably, 1.35< R/S < 2.1;

preferably, 1.55<[V2*C2*(T2-T_{Standard of merit})]/[V1*C1*(T1-T_{Standard of merit})]<1.9; wherein the concentration is 35 °<A<80°。

The invention has the following advantages:

1. according to the invention, through the pressure difference between the previous time and the next time or the accumulated pressure difference detected by the pressure sensing element, the evaporation of the fluid in the pipe can be judged to be basically saturated through the pressure difference, and the volume of the fluid in the pipe is basically not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the pressure difference is reduced to a certain degree, the internal fluid starts to enter a stable state again, and at the moment, the fluid needs to be heated so as to be evaporated and expanded again, so that the electric heater needs to be started for heating. The stable state of the fluid is judged according to the pressure difference or the accumulation of the pressure difference change, so that the result is more accurate, and the problem of error increase caused by aging due to the running time problem is solved.

2. The invention designs that the flow directions of the first fluid and the second fluid are opposite, and further promotes the flow of the phase-change fluid, thereby enhancing the heat transfer.

3. The invention designs a layout of a heat exchange component with a novel structure in a shell, optimizes the optimal relation between the parameters of the heat exchange tube and the flow, specific heat and the like of the fluid through a large number of experiments and numerical simulation, and creatively integrates the flow, the specific heat, the temperature and the target temperature of the heat exchange fluid into the size design of the heat exchanger relative to the previous design, thereby further improving the heat exchange efficiency.

4. Through the flowing direction of fluid in the shell, the reasonable change of the internal diameter and the interval of the tube bundle of the heat exchange tube improves the heat exchange efficiency.

Description of the drawings:

fig. 1 is a schematic structural view of a heat exchanger according to the present invention.

FIG. 2 is a schematic sectional view of a heat exchange member according to the present invention.

Fig. 3 is a top view of a heat exchange member.

Fig. 4 is a schematic diagram of a preferred structure of the heat exchanger.

Fig. 5 is another preferred schematic construction of the heat exchanger.

Fig. 6 is a schematic layout of heat exchange components arranged in a circular shell.

Fig. 7 is a schematic view of the structure of a heat exchange tube.

In the figure: 1. heat exchange tube, 2, right tube box, 3, free end, 4, free end, 5, shell pass inlet connecting tube, 6, shell pass outlet connecting tube, 7, free end, 8, left tube box, 9, connecting point, 10, heat exchange component, 11, shell, 12 tube bundle, 131 first heat exchange tube, 132 second heat exchange tube, front tube plate 14, support 15, support 16, rear tube plate 17, first valve 18, second valve 19,

inlet collecting tube

20, 22, 23,

outlet collecting tube

21, 24, 25

Detailed Description

A shell-and-tube heat exchanger, as shown in fig. 1, the shell-and-tube heat exchanger includes a shell 11, a heat exchange component 10, a shell-side inlet connection pipe 5 and a shell-side outlet connection pipe 6; the heat exchange component 10 is arranged in the shell 11 and fixedly connected to the front tube plate 14 and the rear tube plate 17; the shell side inlet connecting pipe 5 and the shell side outlet connecting pipe 6 are both arranged on the shell 11; fluid enters from a shell side inlet connecting pipe 5, exchanges heat through a heat exchange part and exits from a shell side outlet connecting pipe 6.

Fig. 2 shows a schematic sectional view of a heat exchange part 10 (as viewed from the left side of fig. 1), and as shown in fig. 2, the heat exchange part 10 includes a right tube box 2, a left tube box 8 and a heat exchange tube 1, the heat exchange tube 1 is communicated with the right tube box 2 and the left tube box 8, the left tube box 8 and/or the right tube box 2 is filled with a phase change fluid, and the phase change fluid is in closed circulation in the right tube box 2, the left tube box 8 and the heat exchange tube 1.

The ends of the two ends of the right and left tube boxes are disposed in the openings of the front and

rear tube plates

14, 17 for fixation, as shown in fig. 1.

Preferably, the right and

left headers

2 and 8 extend in the longitudinal direction of the shell side. The shell side preferably extends in the horizontal direction.

As shown in fig. 2, the heat exchanger includes a first heat exchanging pipe 131 and a second heat exchanging pipe 132, the first heat exchanging pipe 131 is disposed through the left channel box 8, and the second heat exchanging pipe 132 is disposed through the right channel box 2; the heat exchange tubes 1 are one or more, each heat exchange tube 1 comprises a plurality of circular arc-shaped tube bundles 12, the central lines of the circular arc-shaped tube bundles 12 are circular arcs taking the axis of the right tube box 2 as a concentric circle, the end parts of the adjacent tube bundles 12 are communicated, and fluid forms serial flow between the right tube box 2 and the left tube box 8, so that the end parts of the tube bundles form tube bundle free ends 3 and 4; the fluid is a phase change fluid, preferably a vapor-liquid phase change liquid. The first and second

heat exchange pipes

131 and 132 flow through a first fluid and a second fluid, respectively. The heat exchange of the three fluids can be carried out among the first fluid, the second fluid and the shell side fluid. For example, the heat exchange process is as follows:

the first fluid is a heat source, the second fluid and the shell pass fluid are cold sources, the phase change fluid in the heat exchange component is subjected to phase change through heat exchange of the first fluid, so that the shell pass fluid is radiated outwards through the tube bundle 12, meanwhile, the vapor phase fluid enters the right tube box 2 to exchange heat with the second fluid, and the condensed fluid after heat exchange returns to the left tube box through the return tube, so that three-fluid heat exchange is realized.

Preferably, the second fluid is a heat source, the first fluid and the shell-side fluid are cold sources, the phase-change fluid in the heat exchange component is subjected to phase change through heat exchange of the second fluid, so that the shell-side fluid is radiated outwards through the tube bundle 12, meanwhile, the vapor-phase fluid enters the left tube box 8 to exchange heat with the first fluid, and the condensed fluid after heat exchange returns to the right tube box through the return tube, so that three-fluid heat exchange is realized.

Preferably, the shell-side fluid is a heat source, the first fluid and the second fluid are cold sources, and the heat exchange of the shell-side fluid enables the fluid in the heat exchange component to absorb heat and exchange heat with the first fluid and the second fluid, so that three-fluid heat exchange is realized.

Preferably, the first fluid is a cold source, the second fluid and the shell-side fluid are heat sources, and heat exchange is realized through the second fluid and the shell-side fluid, so that three-fluid heat exchange is realized.

Preferably, the second fluid is a cold source, the first fluid and the shell-side fluid are heat sources, and the heat exchange between the first fluid and the shell-side fluid is carried out to exchange heat with the second fluid, so that three-fluid heat exchange is realized.

Preferably, the shell-side fluid is a cold source, the first fluid and the second fluid are heat sources, and the heat exchange of the first fluid and the second fluid is carried out to exchange heat with the third shell-side fluid, so that the three-fluid heat exchange is realized.

Preferably, the first heat exchange tube and the second heat exchange tube have the same inner diameter.

The following description focuses on the case where the shell-side fluid is the heat sink and the first and second fluids are the heat sources.

Preferably, as shown in fig. 4 and 5, the first valve 18 and the second valve 19 are arranged at the inlets of the first heat exchange tube 131 and the second heat exchange tube 132, the first valve 18 and the second valve 19 are in data connection with a controller, and the controller controls the opening and closing and the opening of the first valve and the second valve for controlling the flow of the heat exchange fluid entering the first heat exchange tube and the second heat exchange tube.

Research and practice find that the heat exchange of the heat source with continuous power stability can lead to the fluid forming stability of the internal heat exchange component, namely the fluid does not flow or has little fluidity, or the flow is stable, so that the vibration performance of the heat exchange tube 1 is greatly weakened, and the descaling of the heat exchange tube 1 and the heat exchange efficiency are affected. There is therefore a need for improvements to the heat exchangers described above as follows.

In the inventor's prior application, a periodic heat exchange mode is provided, and the vibration of the heat exchange tube is continuously promoted through the periodic heat exchange mode, so that the heat exchange efficiency and the descaling effect are improved. However, adjusting the vibration of the tube bundle with a fixed periodic variation can lead to hysteresis and too long or too short a period. Therefore, the invention improves the previous application and intelligently controls the vibration, so that the fluid in the fluid can realize frequent vibration, and good descaling and heat exchange effects are realized.

Aiming at the defects in the technology researched in the prior art, the invention provides a novel heat exchanger capable of intelligently controlling vibration. The heat exchanger can improve the heat exchange efficiency, thereby realizing good descaling and heat exchange effects.

Self-regulation vibration based on pressure

Preferably, the left and

right tube boxes

8 and 2 are respectively provided with a first pressure sensor and a second pressure sensor for detecting pressures in the left and right tube boxes, the first and second pressure sensors are in data connection with the controller, the controller extracts pressure data of the left and right tube boxes according to a time sequence, obtains a pressure difference or a cumulative value of a change of the pressure difference through comparison of the pressure data of adjacent time periods, and controls opening and closing of the first valve 18 and the second valve 19 according to the pressure difference or the cumulative value of the change of the pressure difference, thereby controlling whether the heat exchange fluid of the first heat exchange tube 131 and the second heat exchange tube 132 passes through heat exchange.

Through the pressure difference of the previous and subsequent time periods or the accumulated pressure difference detected by the pressure sensing element, the evaporation of the fluid inside can be judged to be basically saturated through the pressure difference, and the volume of the fluid inside is basically not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the pressure difference is reduced to a certain degree, the internal fluid starts to enter a stable state again, and at the moment, the fluid needs to be heated so as to be evaporated and expanded again, so that the electric heater needs to be started for heating.

The stable state of the fluid is judged according to the pressure difference or the accumulation of the pressure difference change, so that the result is more accurate, and the problem of error increase caused by aging due to the running time problem is solved.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchange pipe performs heat exchange, and when the second heat exchange pipe does not perform heat exchange, if the left channel pressure of the previous time period is P1 and the left channel pressure of the adjacent subsequent time period is P2, if the difference between P2 and P1 is lower than a threshold value, the controller closes the first valve 18, opens the second valve 19, does not perform heat exchange, and performs heat exchange with the second heat exchange pipe.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchanging pipe does not exchange heat, and when the second heat exchanging pipe exchanges heat, if the right channel pressure in the previous time period is P1 and the right channel pressure in the next subsequent time period is P2, if the difference between P2 and P1 is lower than the threshold value, the controller opens the first valve 18, closes the second valve 19, the first heat exchanging pipe exchanges heat, and the second heat exchanging pipe does not exchange heat.

And determining the running state of the valve according to different conditions by judging the pressure difference in sequence.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchanging pipe exchanges heat, and the second heat exchanging pipe does not exchange heat, if the pressure of the left channel of the previous period is P1 and the pressure of the left channel of the adjacent following period is P2, if P1 is P2, the heating is judged according to the following conditions:

if P1 is greater than the pressure of the first datum, the controller controls the first valve 18 to close and the second valve 19 to open; wherein the first data is greater than the pressure of the phase change fluid after the phase change; preferably the first data is a pressure at which the phase change fluid is substantially phase-changed;

if P1 is less than or equal to the pressure at which the phase change fluid does not change phase, the controller controls first valve 18 to continue to open and second valve 19 to continue to close.

The first data is pressure data in a fully heated state, and the second data is pressure data in the absence of heating or in the beginning of heating. Through the judgment of the pressure, the misjudgment of the overheating or non-heating state is avoided, and the operation state of the valve is determined according to different conditions.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchanging pipe does not exchange heat, and when the second heat exchanging pipe exchanges heat, if the pressure of the right pipe box in the previous period is P1 and the pressure of the right pipe box in the adjacent subsequent period is P2, if P1 is P2, the heating is judged according to the following conditions:

if P1 is greater than the pressure of the first datum, the controller controls the first valve 18 to open and the second valve 19 to close; wherein the first data is greater than the pressure of the phase change fluid after the phase change; preferably the first data is a pressure at which the phase change fluid is substantially phase-changed;

if P1 is less than or equal to the pressure at which the phase change fluid does not change phase, the controller controls the first valve 18 to continue to close and the second valve 19 to continue to open.

Preferably, the pressure sensing elements of the left and right tube boxes are respectively set to be n, and the current time period pressure P of the heating tube box (the left tube box or the right tube box) is calculated sequentially_iPressure Q of the preceding period_i-1Difference D of_i＝P_i-Q_i-1And for n pressure differences D_iPerforming arithmetic cumulative summation

When the value of Y is lower than a set threshold value, the controller controls the valve where the heating channel box is located to be closed, and the valve where the non-heating channel box is located to be opened, so that the heating channel box is switched.

Preferably, if Y is 0, heating is judged according to the following:

if P is_iThe controller controls the valve of the heating channel to be closed, the heating is stopped, and the valve of the other channel is opened; wherein the first data is greater than the pressure of the phase change fluid after the phase change; preferably the pressure at which the phase change fluid substantially changes phase;

if P is_iThe controller controls the valve of the heated chamber to continue to open and the valve of the other chamber to continue to close, wherein the second data is less than or equal to the pressure at which the phase change fluid does not undergo a phase change.

The first data is pressure data in a fully heated state, and the second data is pressure data in the absence of heating or in the beginning of heating.

Preferably, the period of time for measuring the pressure is 1 to 10 minutes, preferably 3 to 6 minutes, and further preferably 4 minutes.

Preferably, the threshold is 100-1000 pa, preferably 500 pa.

Preferably, the pressure value may be an average pressure value over a period of the time period. The pressure at a certain moment in time may also be used. For example, preferably both are pressures at the end of the time period.

Independently adjusting vibration based on temperature

Preferably, the left and

right tube boxes

8 and 2 are respectively provided with a first temperature sensor and a second temperature sensor for detecting the temperature inside the left and right tube boxes, the first and second temperature sensors are in data connection with the controller, the controller extracts the detected temperature data of the left and right tube boxes according to the time sequence, obtains the temperature difference or the accumulation of the temperature difference change through the comparison of the temperature data of the adjacent time periods, and controls the opening and closing of the first valve 18 and the second valve 19 according to the temperature difference or the accumulation of the temperature difference change, thereby controlling whether the heat exchange fluid of the first heat exchange tube 131 and the second heat exchange tube 132 passes through the heat exchange.

The temperature difference or the accumulated temperature difference of the previous time period and the later time period detected by the temperature sensing element can be used for judging that the evaporation of the fluid inside is basically saturated and the volume of the fluid inside is not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the temperature difference is reduced to a certain degree, the internal fluid starts to enter a stable state again, and the fluid needs to be heated to evaporate and expand again, so that the electric heater needs to be started for heating.

The stable state of the fluid is judged according to the temperature difference or the accumulation of the temperature difference change, so that the result is more accurate, and the problem of error increase caused by aging due to the problem of operation time is solved.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchange pipe performs heat exchange, and the second heat exchange pipe does not perform heat exchange, if the left pipe box temperature in the previous time period is T1 and the left pipe box temperature in the next time period is T2, if the difference between T2 and T1 is lower than a threshold value, the controller closes the first valve 18, opens the second valve 19, does not perform heat exchange, and performs heat exchange in the second heat exchange pipe.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchanging pipe does not exchange heat, and when the second heat exchanging pipe exchanges heat, if the right pipe box temperature in the previous time period is T1 and the right pipe box temperature in the next time period is T2, if the difference between T2 and T1 is lower than a threshold value, the controller opens the first valve 18, closes the second valve 19, the first heat exchanging pipe exchanges heat, and the second heat exchanging pipe does not exchange heat.

And determining the running state of the valve according to different conditions by judging the temperature difference in sequence.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchanging pipe exchanges heat, and the second heat exchanging pipe does not exchange heat, if the temperature of the left pipe box in the previous period is T1 and the temperature of the left pipe box in the adjacent subsequent period is T2, if T1 is T2, the heating is judged according to the following conditions:

if T1 is greater than the temperature of the first data, the controller controls the first valve 18 to close and the second valve 19 to open; wherein the first data is greater than the temperature of the phase change fluid after the phase change; preferably the first data is a temperature at which the phase change fluid substantially changes phase;

if T1 is less than or equal to the temperature of the second datum, the controller controls first valve 18 to continue opening and second valve 19 to continue closing, wherein the second datum is less than or equal to the temperature at which the phase change of the phase change fluid does not occur.

The first data is temperature data of a sufficiently heated state, and the second data is temperature data of no heating or temperature data of the beginning of heating. Through the judgment of the temperature, the misjudgment of the overheating or non-heating state is avoided, and the running state of the valve is determined according to different conditions.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchanging pipe does not exchange heat, and when the second heat exchanging pipe exchanges heat, if the temperature of the right pipe box in the previous period is T1 and the temperature of the right pipe box in the adjacent subsequent period is T2, if T1 is T2, the heating is judged according to the following conditions:

if T1 is greater than the temperature of the first data, the controller controls the first valve 18 to open and the second valve 19 to close; wherein the first data is greater than the temperature of the phase change fluid after the phase change; preferably the first data is a temperature at which the phase change fluid substantially changes phase;

if T1 is less than or equal to the temperature of the second datum, the controller controls first valve 18 to continue closing and second valve 19 to continue opening, wherein the second datum is less than or equal to the temperature at which the phase change of the phase change fluid does not occur.

Preferably, the temperature sensing elements of the left and right tube boxes are respectively set to be n, and the current time period temperature T of the heating tube box (the left tube box or the right tube box) is calculated sequentially_iTemperature Q of the preceding time period_i-1Difference D of_i＝T_i-Q_i-1And for n temperature differences D_iPerforming arithmetic cumulative summation

Preferably, if Y is 0, heating is judged according to the following:

if T is_iThe arithmetic mean of the first data is greater than the temperature of the first data, the controller controls the valve of the heating channel to be closed, the heating is stopped, and the valve of the other channel is opened; wherein the first data is greater than the temperature of the phase change fluid after the phase change; preferably the temperature at which the phase change fluid substantially changes phase;

if T is_iIs less than the temperature of the second data, the controller controls the valve of the heated chamber to continue to open and the valve of the other chamber to continue to close, wherein the second data is less than or equal to the temperature at which the phase change fluid does not undergo a phase change.

The first data is temperature data of a sufficiently heated state, and the second data is temperature data of no heating or temperature data of the beginning of heating.

Preferably, the period of time for measuring the temperature is 1 to 10 minutes, preferably 3 to 6 minutes, and further preferably 4 minutes.

Preferably, the temperature value may be an average temperature value over a period of the time period. The temperature at a certain moment in time may also be used. For example, preferably both are temperatures at the end of the time period.

Thirdly, automatically adjusting vibration based on liquid level

Preferably, a first liquid level sensor and a second liquid level sensor are respectively arranged in the left channel box 8 and the right channel box 2 and used for detecting liquid levels in the left channel box and the right channel box, the first liquid level sensor and the second liquid level sensor are in data connection with a controller, the controller extracts detected liquid level data of the left channel box and the right channel box according to a time sequence, an accumulation of liquid level difference or liquid level difference change of the left channel box and the right channel box is obtained through comparison of the liquid level data of adjacent time periods, opening and closing of the first valve 18 and the second valve 19 are controlled according to the accumulation of the liquid level difference or the liquid level difference change, and therefore whether heat exchange fluid of the first heat exchange tube 131 and the second heat exchange tube 132 passes through heat exchange is controlled.

Through the liquid level difference or the accumulated liquid level difference of the front time period and the rear time period detected by the liquid level sensing element, the evaporation of the fluid inside can be judged to be basically saturated through the liquid level difference, and the volume of the fluid inside is basically not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the liquid level difference is reduced to a certain degree, the internal fluid starts to enter a stable state again, and at the moment, the fluid needs to be heated so as to be evaporated and expanded again, so that the electric heater needs to be started for heating.

The stable state of the fluid is judged according to the liquid level difference or the accumulation of the change of the liquid level difference, so that the result is more accurate, and the problem of error increase caused by aging due to the problem of operation time is solved.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchange pipe exchanges heat, and when the second heat exchange pipe does not exchange heat, if the liquid level of the left pipe box in the previous time period is L1 and the liquid level of the left pipe box in the next time period is L2, if the difference between L1 and L2 is lower than the threshold value, the controller closes the first valve 18, opens the second valve 19, does not exchange heat, and the second heat exchange pipe exchanges heat.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchange pipe does not exchange heat, and when the second heat exchange pipe exchanges heat, if the right tank liquid level in the previous time period is L1 and the right tank liquid level in the next time period is L2, if the difference between L1 and L2 is lower than the threshold value, the controller opens the first valve 18, closes the second valve 19, the first heat exchange pipe exchanges heat, and the second heat exchange pipe does not exchange heat.

And determining the running state of the valve according to different conditions by judging the successive liquid level difference.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchange pipe exchanges heat, and the second heat exchange pipe does not exchange heat, if the liquid level of the left pipe box in the previous period is L1, and the liquid level of the left pipe box in the adjacent subsequent period is L2, if L1 is L2, the heating is judged according to the following conditions:

if L1 is less than or equal to the level of the first datum, the controller controls the first valve 18 to close and the second valve 19 to open; wherein the first data is greater than the liquid level of the phase-change fluid after the phase change; preferably the first data is a level at which the phase change fluid is substantially phase changed;

if L1 is greater than or equal to the level at which the phase change fluid has not changed, the controller controls first valve 18 to continue to open and second valve 19 to continue to close.

The first data is liquid level data in a fully heated state, and the second data is liquid level data in the state of no heating or the beginning of heating. Through the judgment of the liquid level, the misjudgment of the overheating or non-heating state is avoided, and the running state of the valve is determined according to different conditions.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchange pipe does not exchange heat, and when the second heat exchange pipe exchanges heat, if the liquid level of the right pipe box in the previous period is L1, and the liquid level of the right pipe box in the adjacent subsequent period is L2, if L1 is L2, the heating is judged according to the following conditions:

if L1 is less than or equal to the level of the first datum, the controller controls the first valve 18 to open and the second valve 19 to close; wherein the first data is greater than the liquid level of the phase-change fluid after the phase change; preferably the first data is a level at which the phase change fluid is substantially phase changed;

if L1 is greater than or equal to the level at which the phase change fluid has not changed, the controller controls first valve 18 to continue to close and second valve 19 to continue to open.

Preferably, the liquid level sensing elements of the left channel box and the right channel box are respectively set to be n, and the liquid level T of the heating channel box (the left channel box or the right channel box) in the current time period is calculated in sequence_iAnd the liquid level Q of the previous time period_i-1Difference D of_i＝T_i-Q_i-1And for n liquid level differences D_iPerforming arithmetic cumulative summation

Preferably, if Y is 0, heating is judged according to the following:

if T is_iIs less than or equal to the liquid level of the first data, the controller controls the valve of the heating tube box to close and stop heating, and the valve of the other tube boxOpening the door; wherein the first data is greater than the liquid level of the phase-change fluid after the phase change; preferably a level at which the phase change fluid is substantially phase-changed;

if T is_iThe controller controls the valve of the heated channel to continue to open and the valve of the other channel to continue to close, wherein the second data is less than or equal to the liquid level at which the phase change fluid does not undergo a phase change.

The first data is liquid level data in a fully heated state, and the second data is liquid level data in the state of no heating or the beginning of heating.

Preferably, the period of time for measuring the liquid level is 1 to 10 minutes, preferably 3 to 6 minutes, and further preferably 4 minutes.

Preferably, the level value may be an average level value over a period of time. The liquid level at a certain moment in time may also be used. For example, preferably both are the liquid level at the end of the time period.

Fourthly, automatically adjusting vibration based on speed

Preferably, a speed sensing element is arranged inside the free end of the tube bundle and used for detecting the flow speed of the fluid in the free end of the tube bundle, the speed sensing element is in data connection with the controller, the controller extracts detected flow speed data according to a time sequence, the flow speed difference or the accumulation of the change of the flow speed difference is obtained through the comparison of the flow speed data of adjacent time periods, and the opening and closing of the first valve 18 and the second valve 19 are controlled according to the accumulation of the flow speed difference or the change of the flow speed difference, so that whether the fluid passes through the first heat exchange tube 131 and the second heat exchange tube 132 for heat exchange is controlled.

The flow velocity difference or the cumulative flow velocity difference of the previous and subsequent time periods detected by the flow velocity sensing element can be used for judging that the evaporation of the fluid inside is basically saturated and the volume of the fluid inside is not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the flow rate difference is reduced to a certain extent, the internal fluid starts to enter a stable state again, and heating is needed at the moment, so that the fluid is evaporated and expanded again, and therefore, the electric heater needs to be started for heating.

The steady state of the fluid is judged according to the flow rate difference or the accumulation of the flow rate difference change, so that the result is more accurate, and the problem of error increase caused by aging due to the operation time problem is solved.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchange pipe performs heat exchange, and when the second heat exchange pipe does not perform heat exchange, if the flow rate in the previous period is L1, and the flow rate in the next subsequent period is L2, if the difference between L2 and L1 is lower than the threshold value, the controller closes the first valve 18, opens the second valve 19, does not perform heat exchange, and performs heat exchange in the second heat exchange pipe.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchange pipe does not exchange heat, and when the second heat exchange pipe exchanges heat, if the flow rate in the previous time period is L1 and the flow rate in the next subsequent time period is L2, if the difference between L2 and L1 is lower than the threshold value, the controller opens the first valve 18, closes the second valve 19, the first heat exchange pipe exchanges heat, and the second heat exchange pipe does not exchange heat.

And determining the running state of the valve according to different conditions by judging the flow speed difference in sequence.

Preferably, when the first valve 18 is opened and the second valve 19 is closed, the first heat exchange pipe performs heat exchange, and the second heat exchange pipe does not perform heat exchange, if the flow rate in the previous period is L1, and the flow rate in the next following period is L2, if L1 is L2, the heating is judged according to the following conditions:

if L1 is greater than or equal to the first data flow rate, the controller controls the first valve 18 to close and the second valve 19 to open; wherein the first data is greater than the flow rate of the phase-change fluid after the phase change; preferably the first data is a flow rate at which the phase change fluid is substantially phase-changed;

if L1 is less than or equal to the flow rate of the second data, the controller controls the first valve 18 to continue to open and the second valve 19 to continue to close, wherein the second data is less than or equal to the flow rate at which the phase change of the phase-change fluid does not occur.

The first data is flow rate data in a fully heated state, and the second data is flow rate data in the absence of heating or in the beginning of heating. Through the judgment of the flow velocity, the misjudgment of the overheating or non-heating state is avoided, and the running state of the valve is determined according to different conditions.

Preferably, when the first valve 18 is closed and the second valve 19 is opened, the first heat exchanging pipe does not exchange heat, and when the second heat exchanging pipe exchanges heat, if the flow rate in the previous period is L1 and the flow rate in the adjacent subsequent period is L2, if L1 is L2, the heating is judged according to the following conditions:

if L1 is greater than or equal to the first data flow rate, the controller controls the first valve 18 to open and the second valve 19 to close; wherein the first data is greater than the flow rate of the phase-change fluid after the phase change; preferably the first data is a flow rate at which the phase change fluid is substantially phase-changed;

if L1 is less than or equal to the flow rate of the second data, the controller controls the first valve 18 to continue to close and the second valve 19 to continue to open, wherein the second data is less than or equal to the flow rate at which the phase change of the phase-change fluid does not occur.

Preferably, the flow velocity sensing elements are set to be n, and the flow velocity T in the current time period is calculated in sequence_iFlow rate Q of the previous time period_i-1Difference D of_i＝T_i-Q_i-1And for n flow rate differences D_iPerforming arithmetic cumulative summation

Preferably, if Y is 0, heating is judged according to the following:

if T is_iThe arithmetic mean of the first data is larger than or equal to the flow rate of the first data, the controller controls the valve of the heating channel to be closed, the heating is stopped, and the valve of the other channel is opened; wherein the first data is greater than the flow rate of the phase-change fluid after the phase change; preferably a flow rate at which the phase change fluid is substantially phase-changed;

if T is_iThe controller controls the valve of the heated channel to continue to open and the valve of the other channel to continue to close, wherein the second data is less than or equal to the flow rate at which the phase change fluid does not undergo a phase change.

The first data is flow rate data in a fully heated state, and the second data is flow rate data in the absence of heating or in the beginning of heating.

Preferably, the period of time for measuring the flow rate is 1 to 10 minutes, preferably 3 to 6 minutes, and further preferably 4 minutes.

Preferably, the flow rate value may be an average flow rate value over a period of the time period. The flow rate at a certain time within the time period may also be used. For example, preferably both flow rates at the end of the time period.

Preferably, the average temperature of the first fluid is equal to the average temperature of the second fluid, and the flow rate of the first fluid per unit time is equal to the flow rate of the second fluid per unit time. The average temperature is an average of the fluid inlet temperature and the fluid outlet temperature.

Preferably, the first fluid and the second fluid are the same fluid.

As shown preferably in fig. 4, the first fluid and the second fluid have a common inlet header 20 and outlet header 21. Fluid enters the inlet header, enters the first heat exchange tube and the second heat exchange tube through the inlet header for heat exchange, and then flows out through the outlet header.

As shown preferably in fig. 5, the first and second fluids have respective inlet and

outlet headers

22, 23, 24, 25, respectively. The fluid enters the respective inlet header, then enters the first and second heat exchange tubes through the inlet header for heat exchange, and then exits through the respective outlet header.

Preferably, the bottom parts of the right channel box and the left channel box are provided with return pipes, so that the fluid condensed in the first channel box and the second channel box can flow quickly.

Preferably, the pipe diameter of the right pipe box 2 is equal to that of the left pipe box 8. The pipe diameters of the right pipe box and the left pipe box are equal, so that the fluid can be ensured to be subjected to phase change in the first box body and keep the same transmission speed as the left pipe box.

Preferably, the connection position 9 of the heat exchange tube at the right tube box is lower than the connection position of the left tube box and the heat exchange tube. Thus, steam can rapidly enter the left pipe box upwards.

Preferably, a return line is provided between the right and left headers, optionally at the ends 18-20 of the right and left headers, to ensure that condensed fluid in the left header can enter the first line.

Preferably, along the flowing direction of the shell-side fluid, the tube diameter of the heat exchange tube bundle is increased continuously.

The pipe diameter range through the heat exchange tube increases, can guarantee that shell side fluid outlet position fully carries out the heat transfer, forms the heat transfer effect like the adverse current, further strengthens the heat transfer effect moreover for whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

Preferably, the heat exchange tubes are arranged in a plurality along the flowing direction of fluid in the shell side, and the distance between every two adjacent heat exchange tubes is gradually reduced along the flowing direction of the fluid.

Preferably, the interval between the heat exchange tubes becomes smaller and larger along the height direction of the right header.

The interval amplitude through the heat exchange tube increases, can guarantee that shell side fluid outlet position fully carries out the heat transfer, forms the heat transfer effect like the adverse current, further strengthens the heat transfer effect moreover for the whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

Preferably, as shown in fig. 7, the casing is a casing with a circular cross section, and a plurality of heat exchange components are arranged in the casing.

Preferably, as shown in fig. 7, one of the plurality of heat exchange members disposed in the housing is disposed at the center of the housing (the center of the right tube box is located at the center of the housing) to serve as a central heat exchange member, and the other heat exchange members are distributed around the center of the housing to serve as peripheral heat exchange members. Through the structural design, the fluid in the shell can fully achieve the vibration purpose, and the heat exchange effect is improved.

Preferably, a line connecting center points of the right header of the peripheral heat exchange member forms a regular polygon.

Preferably, the flow rates of the first fluid and the second fluid of the single peripheral heat exchange member per unit time are respectively smaller than those of the first fluid and the second fluid of the central heat exchange member. Through the design, the center reaches higher vibration frequency to form a central vibration source, so that the periphery is influenced, and better heat transfer enhancement and descaling effects are achieved.

Preferably, on the same horizontal heat exchange section, the fluid needs to achieve uniform vibration, and uneven heat exchange distribution is avoided. Therefore, the flow rates of the first fluid and the second fluid in different heat exchange parts are required to be reasonably distributed. Experiments show that the heat exchange power ratio of the central heat exchange component to the peripheral tube bundle heat exchange component is related to two key factors, wherein one of the two key factors is the distance between the peripheral heat exchange component and the center of the shell (namely the distance between the circle center of the peripheral heat exchange component and the circle center of the central heat exchange component) and the diameter of the shell. Therefore, the invention optimizes the optimal proportional distribution of the flow rate per unit time according to a large number of numerical simulations and experiments.

[V2*C2*(T2-T_{standard of merit})]/[V1*C1*(T1-T_{Standard of merit})]A-b Ln (R/S); ln is a logarithmic function; t is_{Standard of merit}The target temperature of the shell-side fluid after heat exchange is generally set according to the requirement.

a, b are coefficients, wherein 2.0869< a <2.0875,0.6833< b < 0.6837;

preferably, 1.35< R/S < 2.1; further preferred is 1.4< R/S < 2.0;

preferably, 1.55<[V2*C2*(T2-T_{Standard of merit})]/[V1*C1*(T1-T_{Standard of merit})]<1.9. Further preferred is 1.6<[V2*C2*(T2-T_{Standard of merit})]/[V1*C1*(T1-T_{Standard of merit})]<1.8；

Wherein 35 ° < a <80 °.

Preferably, the number of the four-side distribution is 4-5.

Compared with the prior design, the invention creatively integrates the flow rate of the heat exchange fluid per unit time, the specific heat, the temperature and the target temperature into the size design of the heat exchanger, so the structural optimization is also a key invention point of the invention.

The flow rate of the second fluid in unit time of the same heat exchange component is the same as that of the first fluid in unit time, and the inlet temperature is the same. The flow rate per unit time is an average flow rate per unit time. Preferably the second fluid and the first fluid are the same fluid.

The first fluid flow rate per unit time of the peripheral heat exchange member is V2, the inlet temperature is T1, and the specific heat is C1, which is an average of the plurality of peripheral heat exchange members.

Preferably, R is 1600-2400 mm, preferably 2000 mm; s is 1150-1700 mm, preferably 1300 mm; the diameter of the heat exchange tube bundle is 12-20 mm, preferably 16 mm; the outermost diameter of the heat exchange tube is preferably 300-560 mm, preferably 400 mm. The tube diameter of the lower manifold is 100-116 mm, preferably 108 mm, and the length of the upper manifold and the lower manifold is 1.8-2.2 m.

More preferably, a is 2.0872 and b is 0.6835.

Preferably, the box body is of a circular section, and is provided with a plurality of heat exchange components, wherein one heat exchange component is arranged at the center of the circle of the circular section, and the other heat exchange components are distributed around the center of the circle of the circular section. The heat exchange tubes 1 are in one group or multiple groups, each group of heat exchange tubes 1 comprises a plurality of circular arc-shaped tube bundles 12, the central lines of the circular arc-shaped tube bundles 12 are circular arcs of concentric circles, and the end parts of the adjacent tube bundles 12 are communicated, so that the end parts of the heat exchange tubes 1 form tube bundle free ends 3 and 4, such as the free ends 3 and 4 in fig. 2.

Preferably, the heat exchange fluid is a vapor-liquid phase change fluid.

Preferably, the right tube box 2, the left tube box 8 and the heat exchange tube 1 are all of a circular tube structure.

Preferably, the tube bundle of the heat exchange tubes 1 is an elastic tube bundle.

The heat exchange coefficient can be further improved by arranging the tube bundle of the heat exchange tube 1 with an elastic tube bundle.

Preferably, the concentric circles are circles centered on the center of the right header 2. I.e., the tube bundle 12 of heat exchange tubes 1 is arranged around the center line of the right tube box 2.

As shown in fig. 7, the tube bundle 12 is not a complete circle, but rather leaves a mouth, thereby forming the free end of the bundle. The angle of the arc of the mouth part is 65-85 degrees, namely the sum of the included angles b and c in figure 7 is 65-85 degrees.

Preferably, the ends of the tube bundle on the same side are aligned in the same plane, with the extension of the ends (or the plane in which the ends lie) passing through the midline of the right tube box 2.

Preferably, the first end of the inner tube bundle of the heat exchange tube 1 is connected with the right tube box 2, the second end is connected with one end of the adjacent outer tube bundle, one end of the outermost tube bundle of the heat exchange tube 1 is connected with the left tube box 8, and the ends of the adjacent tube bundles are communicated, so that a series structure is formed.

The plane of the first end forms an included angle c of 40-50 degrees with the plane of the central lines of the right tube box 2 and the left tube box 8.

The plane of the second end forms an included angle b of 25-35 degrees with the plane of the center lines of the right tube box 2 and the left tube box 8.

Through the design of the preferable included angle, the vibration of the free end is optimal, and therefore the heat exchange efficiency is optimal.

As shown in fig. 7, the number of tube bundles of heat exchange tube 1 is 4, and tube bundles A, B, C, D are communicated. Of course, the number is not limited to four, and a plurality of the connecting structures are provided as required, and the specific connecting structure is the same as that in fig. 7.

The heat exchange tubes 1 are multiple, the heat exchange tubes 1 are respectively and independently connected with the right tube box 2 and the left tube box 8, and namely the heat exchange tubes 1 are in a parallel structure.

Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A three-fluid heat exchanger capable of controlling heating of a heat exchange tube according to pressure difference comprises a shell, a heat exchange component, a shell side inlet connecting tube and a shell side outlet connecting tube; the heat exchange component is arranged in the shell and fixedly connected to the front tube plate and the rear tube plate; the shell pass inlet connecting pipe and the shell pass outlet connecting pipe are both arranged on the shell; fluid enters from a shell pass inlet connecting pipe, exchanges heat through a heat exchange component and exits from a shell pass outlet connecting pipe; the heat exchange component comprises a right tube box, a left tube box and a heat exchange tube, the heat exchange tube is communicated with the right tube box and the left tube box, the left tube box and/or the right tube box are/is filled with phase-change fluid, and the phase-change fluid is subjected to closed circulation in the right tube box, the left tube box and the heat exchange tube; the heat exchange tubes are one or more, each heat exchange tube comprises a plurality of arc-shaped tube bundles, the central lines of the arc-shaped tube bundles are arcs with the lower tube boxes as concentric circles, and the end parts of the adjacent tube bundles are communicated, so that the end parts of the tube bundles form tube bundle free ends; the heat exchanger comprises a first heat exchange tube and a second heat exchange tube, the first heat exchange tube penetrates through the left tube box, and the second heat exchange tube penetrates through the right tube box; the first heat exchange tube and the second heat exchange tube respectively flow through a first fluid and a second fluid, and heat exchange of three fluids can be carried out among the first fluid, the second fluid and a shell-side fluid;

2. The heat exchanger as claimed in claim 1, wherein when the first valve is opened and the second valve is closed, the first heat exchanging pipe performs heat exchange and the second heat exchanging pipe does not perform heat exchange, if the left channel pressure of the previous period is P1 and the left channel pressure of the adjacent following period is P2, and if the difference between P2 and P1 is lower than the threshold value, the controller closes the first valve, opens the second valve, does not perform heat exchange and the second heat exchanging pipe performs heat exchange.

3. The heat exchanger of claim 2, wherein the housing has a circular cross-section, the heat exchange member is a plurality of, one of the heat exchange members is disposed at a center of the housing to be a central heat exchange member, and the other heat exchange members are distributed around the center of the housing to be peripheral heat exchange members, and a heat exchange power of a single peripheral heat exchange member is smaller than that of the central heat exchange member.

4. A shell-and-tube heat exchanger comprises a shell, a heat exchange component, a shell pass inlet connecting pipe and a shell pass outlet connecting pipe; the heat exchange component is arranged in the shell and fixedly connected to the front tube plate and the rear tube plate; the shell pass inlet connecting pipe and the shell pass outlet connecting pipe are both arranged on the shell; fluid enters from a shell pass inlet connecting pipe, exchanges heat through a heat exchange component and exits from a shell pass outlet connecting pipe; the heat exchange component comprises a right tube box, a left tube box and a heat exchange tube, the heat exchange tube is communicated with the right tube box and the left tube box, the left tube box and/or the right tube box are/is filled with phase-change fluid, and the phase-change fluid is subjected to closed circulation in the right tube box, the left tube box and the heat exchange tube; the heat exchange tubes are one or more, each heat exchange tube comprises a plurality of arc-shaped tube bundles, the central lines of the arc-shaped tube bundles are arcs with the lower tube boxes as concentric circles, and the end parts of the adjacent tube bundles are communicated, so that the end parts of the tube bundles form free ends of the tube bundles.