JP5785800B2 - Vapor absorption refrigerator - Google Patents

Description

  The present invention relates to a vapor absorption refrigerator using steam as a heating source, and more particularly to a dual-effect vapor absorption refrigerator having a high temperature regenerator and a low temperature regenerator and having a drain cooler for cooling the steam. .

  As a double effect steam absorption refrigerator having a high temperature regenerator and a low temperature regenerator and having a drain cooler for cooling the steam, for example, one described in Patent Document 1 (Japanese Patent No. 3724975) is disclosed. is there. In this Patent Document 1, a drain cooler is arranged in a rare solution pipe through which a rare solution sent from an absorber to a high temperature regenerator and a low temperature regenerator flows, and the dilute solution is heated to a concentrated solution by the high temperature regenerator. After the steam supplied for regeneration exits the high temperature regenerator, the drain cooler heats the rare solution by exchanging heat with the rare solution, recovers the heat, and circulates the water itself. It is configured to be discharged.

Japanese Patent No. 3724975

  In the thing of the said patent document 1, the temperature of the steam drain after leaving the said high temperature regenerator is 100 degreeC or more (generally around 155 degreeC with a double effect absorption refrigerator), and this steam drain is discharged | emitted. The For this reason, when the discharged drain is discharged to the atmospheric pressure atmosphere outside the refrigerator at the same temperature, vacuum boiling (flash) is caused. In order to prevent this reduced-pressure boiling, the drain cooler is configured to cool the vapor drain to 100 ° C. or less with the diluted solution from the absorber, and to recover the heat by heating the diluted solution. .

  However, in the thing of patent document 1, the low-temperature dilute solution from an absorber first enters a low-temperature solution heat exchanger, heat-exchanges with a concentrated solution, is heated, and then flows into the drain cooler. Therefore, the temperature of the dilute solution flowing into the drain cooler is relatively high (for example, around 90 ° C.), and the high-temperature steam drain from the high-temperature regenerator is brought to a stable low temperature (for example, 90 ° C. or less) that does not cause boiling under reduced pressure. There is a problem that it is difficult to cool.

  Further, in Patent Document 1, there is also described an example in which a dilute solution from an absorber is led directly to a drain cooler to cool the vapor drain. In this example, a low-temperature dilute solution from an absorber is used. Because it is configured to always branch to the drain cooler at a constant rate, the steam drain is cooled more than necessary at the partial load (low load) of the refrigerator, and the rare solution flowing to the low temperature solution heat exchanger and the high temperature solution heat exchanger Since the flow rate is reduced by the amount that flows through the drain cooler, the temperature of the concentrated solution supplied to the absorber cannot be lowered sufficiently, and heat recovery from the concentrated solution becomes insufficient, and the efficiency of the refrigerator at partial load Is not fully considered.

  An object of the present invention is to obtain a vapor absorption type refrigerator that can reliably cool the steam drain from the high-temperature regenerator to a stable temperature that does not cause reduced-pressure boiling and can also improve the efficiency of the refrigerator at the time of partial load. .

In order to achieve the above object, the present invention comprises a high-temperature regenerator, a low-temperature regenerator, a condenser, an evaporator, and an absorber that use steam as a heating source, and further comprises a rare solution that has absorbed refrigerant vapor in the absorber. A dilute solution pipe sent from the absorber to the high temperature regenerator and the low temperature regenerator; a concentrated solution pipe sending the concentrated solution concentrated in the high temperature regenerator and the low temperature regenerator to the absorber; and a rare solution flowing through the dilute solution pipe. A low temperature solution heat exchanger and a high temperature solution heat exchanger for exchanging heat between the solution and the concentrated solution flowing through the concentrated solution pipe; a drain pipe through which the steam drain from the high temperature regenerator flows; and a steam drain provided in the drain pipe In the vapor absorption type refrigerator having a drain cooler for cooling, a bypass pipe branched from the rare solution pipe and bypassing the low temperature solution heat exchanger is provided, and the drain cooler is diluted from the bypass pipe. The steam drain from the drain pipe is configured to exchange heat, and the flow control valve provided upstream of the drain cooler in the bypass pipe and the temperature of the steam drain provided in the drain pipe are detected. And a control device for controlling the drain temperature discharged by adjusting the flow rate control valve of the bypass pipe according to the temperature detected by the temperature detector, and the drain cooler is provided downstream of the drain pipe. A low-temperature drain cooler disposed on the side and a high-temperature drain cooler disposed on the upstream side of the drain pipe, and the low-temperature drain cooler is a bypass branched from the rare-solution pipe so as to bypass the low-temperature solution heat exchanger The dilute solution flowing in the pipe and the steam drain are configured to exchange heat, and the high temperature drain cooler The dilute solution flowing through the bypass pipe branched from the dilute solution pipe so as to bypass the liquid heat exchanger is configured to exchange heat with the steam drain, and the low temperature drain cooler and the high temperature are bypassed to the drain cooler. A drain bypass pipe that connects a drain pipe between the drain cooler and a drain pipe downstream of the low-temperature drain cooler is provided, and a branch portion of the drain pipe between the drain bypass pipe and the low-temperature drain cooler 11 and the drain Each bypass pipe is provided with a flow control valve for steam drain .

Another feature of the present invention is a high temperature regenerator that separates refrigerant vapor from a solution using supplied steam as a heating source, and a low temperature regeneration that separates refrigerant vapor from a solution using the refrigerant vapor separated by the high temperature regenerator as a heating source. A condenser for liquefying the refrigerant vapor separated by the low-temperature regenerator, an evaporator for converting the refrigerant liquefied by the condenser into steam, and an absorber for absorbing the refrigerant vapor generated by the evaporator into the solution, A dilute solution pipe for sending the dilute solution that has absorbed the refrigerant vapor from the absorber to the high temperature regenerator and the low temperature regenerator, and a concentrated solution in which the refrigerant vapor is separated and concentrated in the high temperature regenerator and the low temperature regenerator A high temperature solution heat exchanger, a low temperature solution heat exchanger and a high temperature solution heat exchanger for exchanging heat between the concentrated solution pipe for sending the liquid to the absorber, the diluted solution flowing through the diluted solution pipe and the concentrated solution flowing through the concentrated solution pipe Discharged from the regenerator In the steam absorption refrigerator having a drain pipe through which the steam drain flows and a drain cooler provided in the drain pipe for cooling the steam drain, the branch is branched from the upstream side of the low temperature solution heat exchanger in the rare solution pipe. A bypass pipe connected to the dilute solution pipe on the downstream side of the low temperature solution heat exchanger is provided, and the drain cooler is configured to exchange heat between the dilute solution from the bypass pipe and the steam drain from the drain pipe. In addition, a flow rate control valve for a rare solution provided in the bypass pipe upstream from the drain cooler, a temperature detector provided in the drain pipe for detecting the temperature of the steam drain, and detected by the temperature detector A control device for controlling the temperature of the drain to be discharged by adjusting the flow rate of the dilute solution flowing through the bypass pipe according to the temperature of the steam drain Wherein the Dorenkura, the low-temperature Dorenkura disposed downstream of the drain pipe, is composed of arranged hot Dorenkura upstream of the drain pipe, said cold Dorenkura bypasses the low-temperature solution heat exchanger The dilute solution flowing through the bypass pipe branched from the dilute solution pipe and the steam drain are configured to exchange heat, and the high temperature drain cooler is connected to the dilute solution pipe so as to bypass the high temperature solution heat exchanger. The dilute solution flowing through the branched bypass pipe and the steam drain are configured to exchange heat, and the drain pipe between the low temperature drain cooler and the high temperature drain cooler and the downstream side of the low temperature drain cooler are bypassed so as to bypass the drain cooler. A drain bypass pipe for connecting the drain pipe and the drain pipe is provided. The flow control valve of the steam drain is provided between the branch portion of the drain bypass pipe and the low-temperature drain cooler 11 and in the drain bypass pipe .

  ADVANTAGE OF THE INVENTION According to this invention, the vapor | steam absorption type refrigerator which can cool the steam drain from a high temperature regenerator reliably to the stable temperature which does not raise | generate a pressure reduction boiling, and can also improve the refrigerator efficiency at the time of partial load can be obtained. .

It is a cycle system diagram which shows Example 1 of the vapor | steam absorption refrigerator of this invention. It is a cycle system | strain diagram of the principal part which shows the partial modification of FIG. It is a cycle system diagram of the principal part which shows the other partial modification of FIG. It is a cycle system diagram which shows Example 2 of the vapor | steam absorption refrigerator of this invention. It is a cycle system diagram which shows Example 3 of the vapor | steam absorption refrigerator of this invention.

  Hereinafter, specific examples of the vapor absorption refrigerator of the present invention will be described with reference to the drawings.

A first embodiment of the vapor absorption refrigerator according to the present invention will be described with reference to FIG.
FIG. 1 is a cycle system diagram of a steam tank absorption chiller / heater according to Embodiment 1 of the present invention. In the figure, 1 is an evaporator, 2 is an absorber, 3 is a condenser, 4 is a low temperature regenerator, 5 is a high temperature regenerator, 6 is a rare solution pump, 7 is a concentrated solution pump, 8 is a refrigerant pump, and 9 is a low temperature. A solution heat exchanger, 10 is a high temperature solution heat exchanger, and 11 and 12 are drain coolers. In this embodiment, the drain cooler is composed of two drain coolers, a low temperature drain cooler 11 and a high temperature drain cooler 12. In this embodiment, water is used as the refrigerant and lithium bromide is used as the solution.

  The evaporator 1 is divided into a first evaporator 1a (low stage side evaporator) and a second evaporator 1b (high stage side evaporator) by a partition wall 21, and a refrigerant distributor is disposed above the first evaporator 1a. (Refrigerant spraying device) 17 is installed, and the partition wall 21 is provided with a refrigerant redistributor (refrigerant spraying device) 19 that collects the coolant liquid flowing down the first evaporator 1a and sprays it to the second evaporator 1b. It has been.

  The absorber 2 is divided into a first absorber 2a (low-stage side absorber) and a second absorber 2b (high-stage side absorber) by a partition wall 22, respectively, and a solution is provided above the first absorber 2a. A distributor (solution spraying device) 18 is installed, and a solution redistributor (solution spraying device) 20 for collecting the solution flowing down the first absorber 2a and spraying it on the second absorber 2b is provided on the partition wall 22. It has been.

  The first evaporator 1a and the first absorber 2a are communicated so that refrigerant vapor flows through an eliminator, and the second evaporator 1b and the second absorber 2b also flow through refrigerant through the eliminator. It is communicated to.

  A refrigerant liquid reservoir is provided at the lower part of the second evaporator 1b, and a refrigerant pipe 43 connecting the bottom of the refrigerant liquid reservoir and the refrigerant distributor 17 installed at the upper part of the first evaporator 1a is provided. The refrigerant pipe 8 is installed in the refrigerant pipe 43, and the first evaporation of the refrigerant liquid in the refrigerant liquid reservoir from the refrigerant distributor 17 installed in the upper part of the first evaporator 1a. It spreads in the container 1a. The refrigerant liquid sprayed from the refrigerant distributor 17 evaporates by taking heat from the cold water flowing in the evaporator while flowing down the first evaporator 1 a, and the refrigerant that has not been partitioned off is collected in the refrigerant redistributor 19. The refrigerant redistributor 19 is sprayed on the second evaporator 1b. The refrigerant liquid sprayed on the second evaporator 1b evaporates by taking heat from the cold water flowing in the evaporator while flowing down the second evaporator 1b, and the refrigerant liquid that has not been divided by the evaporation is stored in the second evaporator 1b. Stored at the bottom. The cold water is cooled in the evaporator 1 by supplying cold water of 12 ° C., for example, from a cold water load (such as an indoor cooling load) through the cold water inlet pipe 24 into an evaporator heat transfer tube provided in the evaporator 1. Thus, for example, 7 ° C. cold water is supplied again from the cold water outlet pipe 25 to the cold water load.

  The concentrated solution concentrated in the high-temperature regenerator 5 and the low-temperature regenerator 4 is sprayed from a solution distributor (solution spraying device) 18 installed above the first absorber 2a via the concentrated solution pump 7. Then, the refrigerant vapor evaporated in the first evaporator 1a while flowing down the first absorber 2a is absorbed, and the solution whose concentration is reduced by absorbing the refrigerant vapor is the solution redistributor (solution spraying device) 20 Collected in the second absorber 2b. The sprayed solution absorbs the refrigerant vapor evaporated in the second evaporator 1b while flowing down the second absorber 2b, and the diluted solution having a further reduced concentration by absorbing the refrigerant vapor is the second solution. It is once stored in the lower part of the absorber 2 b and then sent to the high temperature regenerator 1 and the low temperature regenerator 2 by the dilute solution pump (solution circulation pump) 6. Absorption heat generated when the refrigerant vapor is absorbed is cooled by cooling water flowing in the absorber 2. This cooling water is supplied from a cooling water inlet pipe 26 into an absorber heat transfer pipe provided in the absorber 2, passes through the absorber 2, passes through the condenser 3, and is then supplied to a cooling water outlet pipe 27. Discharged from.

The refrigerant pipe 43 on the downstream side of the refrigerant pump 8 is provided with a refrigerant pipe 44 branched from the refrigerant pump 8 and connected to the second absorber 2b. The refrigerant pipe 44 has a control valve (not shown). Is provided.
The dilute solution exiting the dilute solution pump 6 is heat-exchanged with the concentrated solution from the high-temperature regenerator 5 and the low-temperature regenerator 4 in the low-temperature solution heat exchanger 9 and then rises in temperature. The remaining temperature is sent to the low-temperature regenerator 4 through 48, and the remainder is further heat-exchanged with the concentrated solution from the high-temperature regenerator 5 in the high-temperature solution heat exchanger 10 to rise in temperature, and then sent to the high-temperature regenerator 5.

  For example, steam at 174 ° C. is supplied from the boiler 39 to the high-temperature regenerator 5 through the steam flow rate adjusting valve 34 and the steam inlet pipe 28, and the solution in the high-temperature regenerator 5 is heated by this steam to generate a refrigerant. As the vapor is generated, the solution is concentrated. This concentrated concentrated solution is sent from the high temperature regenerator 5 through the concentrated solution pipe 54 to the high temperature solution heat exchanger 10, and is cooled by exchanging heat with the dilute solution from the absorber 2. To the concentrated solution flowing in through the concentrated solution pipe 55 and sent to the concentrated solution pump (solution spray pump) 7. The solution exiting the concentrated solution pump 7 is cooled by exchanging heat with the dilute solution from the absorber 2 in the low temperature solution heat exchanger 9, and sent to the solution distributor 18 installed at the upper part of the first absorber 2a. .

  The refrigerant vapor generated in the high temperature regenerator 5 is sent to the low temperature regenerator 4 through a refrigerant vapor pipe 45. In the low-temperature regenerator 4, a low-temperature regenerator heat transfer tube 46 through which refrigerant vapor from the high-temperature regenerator 5 flows and a solution spraying device 47 installed on the low-temperature regenerator heat transfer tube 46 are installed. A part of the dilute solution branched from the outlet of the low-temperature solution heat exchanger 9 is supplied to the solution sprayer 47 via a branch pipe (rare solution pipe) 48 and sprayed into the low-temperature regenerator 4. The sprayed dilute solution is heated by the refrigerant vapor from the high temperature regenerator 4 while flowing down the low temperature regenerator heat transfer tube 46 to generate refrigerant vapor.

  After the refrigerant vapor is generated and the concentration of the solution is temporarily stored in the lower part of the low temperature regenerator 4, the concentrated solution from the high temperature regenerator 5 is upstream of the concentrated solution pump 7 as described above. The solution merges and is sent to the solution distributor 18 via the low-temperature solution heat exchanger 9.

  The refrigerant vapor sent from the high-temperature regenerator 5 to the low-temperature regenerator heat transfer tube 46 of the low-temperature regenerator 4 heats the dilute solution flowing through the low-temperature regenerator 4 to condense itself, and this condensed refrigerant liquid Is decompressed by a decompression mechanism (not shown) and sent to the condenser 3.

  The refrigerant vapor generated in the low temperature regenerator 4 is sent to the condenser 3 through an eliminator passage, and is cooled and condensed by cooling water flowing in the condenser 3. The condensed refrigerant liquid is temporarily stored in the lower part of the condenser 3 and sent to the evaporator 1 through a pressure reducing mechanism (not shown).

  The cold water outlet pipe 25 is provided with a cold water outlet temperature detector 32. The cold water outlet temperature controller 33 controls the cold water outlet temperature detector 32 so that the temperature detected by the cold water outlet temperature detector 32 falls within a predetermined temperature range. The steam flow control valve 34 is controlled to adjust the amount of steam input to the high temperature regenerator 5.

  The boiler 39 is supplied to the high-temperature regenerator 5 at 174 ° C., for example, and the dilute solution is heated by the high-temperature regenerator 5 to become steam drain at, for example, 155 ° C., and is discharged from the high-temperature regenerator 5 to the drain pipe 29. The steam drain then passes through the high-temperature drain cooler 12, the drain pipe 30, and the low-temperature drain cooler 11, and is cooled to a temperature of generally 90 ° C. or lower, for example, 55 ° C., by a part of the rare solution from the absorber 2. Then, the water is returned to the drain tank 38 released to the atmosphere through the drain pipe 31. The water in the drain tank 38 is sent again to the boiler 39 by the drain pump 42 to become steam and is supplied to the high temperature regenerator 5 to repeat the cycle.

  The low-temperature drain cooler 11 is provided in the middle of a bypass pipe 50 branched from a rare-solution pipe 49 between the dilute solution pump 6 and the low-temperature solution heat exchanger 9, for example, a steam drain of 115 ° C. from the drain pipe 30. And heat exchange with a low temperature (for example, 35 ° C.) dilute solution flowing through the bypass pipe 50. The outlet side of the low-temperature drain cooler 11 of the bypass pipe 50 is connected to the branch pipe 48 connected to the low-temperature regenerator 4.

  The high-temperature drain cooler 12 branches from a rare solution pipe 51 between the low-temperature solution heat exchanger 9 and the high-temperature solution heat exchanger 10 and is bypass piping provided to bypass the high-temperature solution heat exchanger 10. For example, the steam drain at 155 ° C. from the drain pipe 29 and the dilute solution at 90 ° C. flowing through the bypass pipe 52 are heat-exchanged.

  Since the temperature of the steam drain after passing through the high-temperature drain cooler 12 is 100 ° C. or higher depending on operating conditions such as during rated operation, in this embodiment, as described above, a low temperature for heat exchange with a low-temperature dilute solution. A drain cooler 11 is further provided, and the steam drain temperature of 100 ° C. or higher is exchanged with a low-temperature dilute solution, so that the vapor drain temperature is reduced to 90 ° C. or lower so as not to cause boiling under reduced pressure even when the steam drain is opened to the atmosphere. After being reliably lowered, it is discharged out of the refrigerator.

By comprising in this way, in the said drain coolers 11 and 12, a vapor | steam drain can be heat-exchanged with a dilute solution, and can be made low temperature stably.
In order to increase the amount of heat recovered from the steam drain, the temperature of the steam drain from the low-temperature drain cooler 11 is designed to be, for example, 55 ° C. during rated operation.

  However, when the load on the refrigerator is reduced to a partial load, the steam drain temperature after passing through the high-temperature regenerator 5 decreases, and the steam drain temperature after passing through the high-temperature drain cooler 12 and the low-temperature drain cooler 11 is also reduced. It goes down with it. However, although the heat recovered from the steam drain by the low-temperature drain cooler 11 is used for heating the rare solution sent to the low-temperature regenerator 4, the energy efficiency in the low-temperature regenerator 4 is low, and the coefficient of performance (COP) is 0.7. Therefore, the heat recovery efficiency with respect to the recovered heat amount is lowered. On the other hand, as in this embodiment, when the steam drain whose temperature has decreased is supplied to the boiler 39 and used again in a closed cycle, a large amount of heating is required for the amount of heat recovered by the low-temperature drain cooler 11. become. Therefore, it has been found that when steam (or hot water) is used in a closed cycle, it is preferable to minimize the heat recovery in the low-temperature drain cooler 11.

  Even when steam (or water) is not used in a closed cycle, even in a system in which hot water discharged from the low-temperature drain cooler 11 is reused for hot water supply or the like, similarly, in the low-temperature drain cooler 11 It is preferable to minimize heat recovery.

  Therefore, in this embodiment, a flow control valve 37 for a rare solution is provided on the upstream side of the low-temperature drain cooler 11 in the bypass pipe 50, and a steam drain is provided in the drain pipe 30 between the low-temperature drain cooler 11 and the high-temperature drain cooler 12. And a drain temperature control device 36 for controlling the opening degree of the flow rate control valve 37 in accordance with the temperature of the steam drain detected by the temperature detector 35. . This drain temperature control device 36 is based on the steam drain temperature upstream of the low-temperature drain cooler 11, the drain temperature on the outlet side of the low-temperature drain cooler 11 is a stable temperature that does not cause vacuum boiling, and the amount of heat recovered from the steam drain is also high. The dilute solution flow control valve 37 is controlled so that the temperature can be reduced as much as possible, for example, 90 to 55 ° C, preferably 90 to 80 ° C.

  Thereby, at the time of rated operation, the said flow control valve 37 is controlled so that the drain temperature by the side of the said low-temperature drain cooler 11 may be 90 degreeC. Further, at the time of partial load operation, the drain temperature at the inlet side of the low-temperature drain cooler 11 is lowered. Therefore, if the temperature is, for example, 90 ° C. or less, the drain temperature control device 36 fully closes the flow rate adjusting valve 37. Control. Therefore, according to the present embodiment, the heat recovery from the steam drain can be minimized, so that the recovered heat is less consumed by the low-temperature regenerator 4 with low energy efficiency, and the amount of heat is reduced by the boiler 39. The amount of heat thrown can be reduced, and the efficiency can be improved. Further, since the flow rate of the dilute solution flowing through the bypass pipe 50 can be minimized, the low temperature dilute solution from the absorber 2 can be effectively used for cooling the concentrated solution by the low temperature solution heat exchanger 9, and as a whole The energy efficiency of the vapor absorption refrigerator can be improved. In particular, during partial load operation, the opening degree of the dilute solution flow rate control valve 37 is controlled to be fully closed or a small opening degree, thereby obtaining an effect that energy efficiency can be particularly improved.

  As described above, according to this embodiment, the temperature of the steam drain after passing through the high-temperature drain cooler 12 is measured by the temperature detector 35, the temperature of the drain discharged outside the refrigerator is as high as possible, and the pressure is reduced. Since the drain temperature control device 36 controls the flow control valve 37 of the diluted solution to adjust the bypass flow rate of the diluted solution so that the temperature does not cause boiling, the reduced pressure boiling (flush) of the drain is prevented. However, since the drain temperature is not lowered more than necessary particularly during partial load, a vapor absorption refrigerator having a high coefficient of performance (COP) can be obtained.

  2 is a partial modification of the first embodiment shown in FIG. 1. In the example shown in FIG. 2, the steam drain temperature of the drain pipe 30 between the low-temperature drain cooler 11 and the high-temperature drain cooler 12 shown in FIG. Instead of the temperature detector 35 for detecting the temperature, a temperature detector 35a is provided in the drain pipe 31 downstream of the low-temperature drain cooler 11, and the temperature of the drain discharged from the low-temperature drain cooler 11 is directly measured. Based on the drain temperature after passing through the low-temperature drain cooler 11, the drain temperature control device 36 controls the flow control valve 37 of the rare solution so that the drain temperature is as high as possible and does not cause boiling under reduced pressure. Then, since the bypass flow rate of the dilute solution is adjusted, the same effect as the example shown in FIG. 1 can be obtained. In addition, in the example shown in FIG. 2, the temperature of the drain cooler exiting from the low-temperature drain cooler 11 is directly measured, and the bypass flow rate of the rare solution (that is, the opening degree of the flow control valve 37 is adjusted so that the measured temperature becomes the target temperature. ) Is controlled, temperature control with higher accuracy becomes possible. In FIG. 2, since the other configuration is the same as that in FIG.

FIG. 3 shows still another partial modification of the first embodiment shown in FIG. In this example, a drain bypass pipe 53 is provided so that the drain pipe 30 between the low-temperature drain cooler 11 and the high-temperature drain cooler 12 and the drain pipe 31 on the downstream side of the low-temperature drain cooler 11 bypass the low-temperature drain cooler 11. . Further, steam drain flow control valves 40 and 41 are provided between the branch of the drain pipe 30 with the drain bypass pipe 53 and the low-temperature drain cooler 11 and in the drain bypass pipe 53 , respectively. These flow rate control valves 40 and 41 may be valves that can adjust the opening degree so that the flow rate can be adjusted, or open / close valves (for example, electromagnetic valves) that can be controlled only fully open and fully closed. The opening control of the flow rate adjusting valves 40 and 41 is configured to be controlled by the control device 36 based on the opening degree of the dilute solution flow rate adjusting valve 37. For example, the dilute solution flow rate adjusting valve 37 is entirely controlled. When closed, the flow control valve 40 is also fully closed, and the flow control valve 41 is controlled by the control device 36 so as to be fully open.

With this configuration, it is possible to prevent crystallization of the solution in the low-temperature drain cooler 11 when the dilute solution flow control valve 37 is fully closed. That is, in the case of FIG. 1, when the flow control valve 37 for the dilute solution is fully closed, the dilute solution stays in the low-temperature drain cooler 11, but the steam drain from the drain pipe 30 continues to flow. Therefore, the staying rare solution may be heated and concentrated. For this reason, when the flow control valve 37 of the dilute solution is fully closed so that the solution does not crystallize when the temperature in the low-temperature drain cooler 11 is lowered, such as when the refrigerator is stopped, the flow control valve 40 is set. By controlling the control device 36 so that the flow control valve 41 is fully opened when fully closed, the effect of reliably preventing crystallization of the solution can be obtained.
In FIG. 3, the other components are the same as those in FIG.

Embodiment 2 of the vapor absorption refrigerator according to the present invention will be described with reference to FIG. In FIG. 4, the parts denoted by the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.
The difference between the second embodiment and the first embodiment shown in FIG. 1 will be described. In Example 1 of FIG. 1, the outlet side of the low-temperature drain cooler 11 of the bypass pipe 50 provided with the low-temperature drain cooler 11 is configured to be connected to the branch pipe 48 connected to the low-temperature regenerator 4. In the second embodiment shown in FIG. 2, the pipe is not connected to the branch pipe 48 but is connected to a rare solution pipe 51 between the low temperature solution heat exchanger 9 and the high temperature solution heat exchanger 10. Further, in this embodiment, the connection portion of the bypass pipe 50 to the dilute solution pipe 51 is located upstream from the portion where the branch pipe 48 branches.

  With this configuration, the dilute solution whose temperature has been recovered from the steam drain by the low-temperature drain cooler 11 and whose temperature has increased via the branch pipe 48 as in the first embodiment is low-temperature regeneration with low energy efficiency. A part of the heat is not sent to the cooler 4 but is also sent to the high-temperature regenerator 5 with high energy efficiency. Therefore, the heat recovery efficiency with respect to the amount of heat recovered from the steam drain is increased, and the coefficient of performance of the refrigerator can be further improved.

  In addition, the connection part to the dilute solution pipe 51 on the outlet side of the low-temperature drain cooler 11 of the bypass pipe 50 may be downstream from the part where the branch pipe 48 branches. In this case, the low-temperature drain cooler 11 may Since the entire amount of the diluted solution whose temperature has been recovered by heat recovery is sent to the high-temperature regenerator 5 with good energy efficiency, the heat recovery efficiency is further increased and the coefficient of performance of the refrigerator can be further improved.

Other configurations are the same as those of the first embodiment shown in FIG.
Further, as shown in FIG. 2, a temperature detector 35a may be provided in the drain pipe 31 on the downstream side of the low-temperature drain cooler 11, and the same control as in FIG. 2 may be performed.

  Further, as shown in FIG. 3, a steam drain bypass pipe 53 for bypassing the low-temperature drain cooler 11 is provided, and steam drain flow rate adjusting valves 40 and 41 are provided as in FIG. Also good.

Embodiment 3 of the vapor absorption refrigerator according to the present invention will be described with reference to FIG. In FIG. 5, the parts denoted by the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.
The difference between the third embodiment and the first embodiment shown in FIG. 1 will be described. In the first embodiment shown in FIG. 1, two drain coolers, a low-temperature drain cooler 11 and a high-temperature drain cooler 12, are provided. In this third embodiment, only one drain cooler 13 is provided. A steam drain of, for example, 155 ° C. from the drain pipe 29 and a low-temperature (eg, 35 ° C.) flowing through the bypass pipe 56 are provided in the middle of the bypass pipe 56 branched from the dilute solution pipe 49 to the heat exchanger 9. Heat is exchanged with the dilute solution, and the drain cooler 13 outlet side of the bypass pipe 56 is connected to the dilute solution pipe 57 on the downstream side of the high temperature solution heat exchanger 10.

  Further, a steam drain temperature detector 35 b is provided in the drain pipe 29, and the steam drain temperature control device 36 is a steam drain temperature upstream of the drain cooler 13, that is, the temperature of the hot steam drain discharged from the high temperature regenerator 5. Based on this steam drain temperature, the drain temperature on the outlet side of the drain cooler 13 is a stable temperature that does not cause vacuum boiling, and a temperature that can reduce the amount of heat recovered from the steam drain as much as possible. The dilute solution flow control valve 37 is controlled.

  Thereby, at the time of rated operation, the said flow control valve 37 is controlled so that the drain temperature by the side of the said drain cooler 13 will be 90-80 degreeC, for example. Further, during the partial load operation, the drain temperature at the inlet side of the drain cooler 13 is lowered, so that the opening degree of the flow rate adjusting valve 37 is controlled accordingly, and the drain temperature at the outlet side of the drain cooler 13 is 90, for example. ˜80 ° C.

  Also in the present embodiment, the same effect as in the first embodiment or the second embodiment can be obtained. Further, according to the present embodiment, only one drain cooler 13 is required, the configuration is simplified, and the heat recovered from the steam drain is consumed by the high-temperature regenerator 5 with high energy efficiency. The amount of heat thrown in can be reduced, and the efficiency can be improved. Furthermore, since the flow rate of the dilute solution flowing through the bypass pipe 50 can be minimized, the low temperature dilute solution from the absorber 2 can be effectively used for cooling the concentrated solution by the low temperature solution heat exchanger 9 and the high temperature solution heat exchanger 10. From this point, the energy efficiency of the vapor absorption chiller can be improved. In particular, the energy efficiency can be improved by controlling the opening of the dilute solution flow control valve 37 to a small opening during partial load operation. There is an effect that can be particularly improved.

Other configurations are the same as those of the first embodiment shown in FIG.
Also in this embodiment, similarly to the one shown in FIG. 2, the temperature detector 35a is provided in the drain pipe 31 on the downstream side of the drain cooler 13 (low temperature drain cooler 11) so as to perform the same control as in FIG. Further, as shown in FIG. 3, a steam drain bypass pipe 53 for bypassing the drain cooler 13 (low temperature drain cooler 11) is provided, and steam drain flow rate adjusting valves 40 and 41 are provided as in FIG. You may perform control similar to FIG.

1: evaporator, 1a: first evaporator, 1b: second evaporator,
2: absorber, 2a: first absorber, 2b: second absorber,
3: Condenser,
4: Low temperature regenerator, 5: High temperature regenerator,
6: dilute solution pump, 7: concentrated solution pump, 8: refrigerant pump,
9: Low temperature solution heat exchanger, 10: High temperature solution heat exchanger,
11-13: Drain cooler (11: low temperature drain cooler, 12: high temperature drain cooler),
17: Refrigerant distributor (refrigerant spraying device), 18: Solution distributor (solution spraying device),
19: Refrigerant redistributor, 20: Solution redistributor,
21: evaporator partition, 22: absorber partition,
24: Cold water inlet piping, 25: Cold water outlet piping,
26: Cooling water inlet piping, 27: Cooling water outlet piping,
28: Steam inlet piping,
29, 30, 31: drain piping,
32: Cold water outlet temperature detector, 33: Cold water outlet temperature control device,
34: Steam flow control valve,
35, 35a, 35b: temperature detector,
36: Drain temperature control device,
37: Flow control valve for dilute solution,
38: Drain tank,
39: Boiler,
40, 41: Steam drain flow control valve,
42: drain pump,
43, 44: Refrigerant piping, 45: Refrigerant vapor piping,
46: Low-temperature regenerator heat transfer tube, 47: Solution spraying device,
48: branch piping (diluted solution piping), 49, 51, 57: diluted solution piping,
50, 52, 53, 56: Bypass piping,
54, 55: Concentrated solution piping.

Claims (10)

A high-temperature regenerator, a low-temperature regenerator, a condenser, an evaporator, and an absorber that use steam as a heating source, and further, a rare solution that has absorbed refrigerant vapor in the absorber is transferred from the absorber to the high-temperature regenerator and the low-temperature regenerator. A dilute solution pipe that is sent to the high temperature regenerator and a concentrated solution pipe that sends the concentrated solution concentrated in the low temperature regenerator to the absorber, a dilute solution that flows through the dilute solution pipe, and a concentrated solution that flows through the concentrated solution pipe A low-temperature solution heat exchanger and a high-temperature solution heat exchanger for exchanging heat, a drain pipe through which steam drain from the high-temperature regenerator flows, and a steam absorption refrigerator equipped with the drain cooler provided in the drain pipe for cooling the steam drain In
A bypass pipe branched from the dilute solution pipe and bypassing the low temperature solution heat exchanger is provided, and the drain cooler is configured to exchange heat between the dilute solution from the bypass pipe and the steam drain from the drain pipe,
A flow control valve provided on the upstream side of the drain cooler in the bypass pipe;
A temperature detector provided in the drain pipe for detecting the temperature of the steam drain;
A control device for controlling the drain temperature discharged by adjusting the flow rate control valve of the bypass pipe according to the temperature detected by the temperature detector ;
The drain cooler includes a low-temperature drain cooler disposed on the downstream side of the drain pipe and a high-temperature drain cooler disposed on the upstream side of the drain pipe, and the low-temperature drain cooler bypasses the low-temperature solution heat exchanger. The dilute solution flowing through the bypass pipe branched from the dilute solution pipe is configured to exchange heat with the steam drain, and the high temperature drain cooler is branched from the dilute solution pipe to bypass the high temperature solution heat exchanger. The dilute solution flowing through the bypass pipe and the steam drain are configured to exchange heat,
A drain bypass pipe that connects a drain pipe between the low temperature drain cooler and the high temperature drain cooler and a drain pipe downstream of the low temperature drain cooler so as to bypass the drain cooler, and the drain bypass pipe of the drain pipe; A steam absorption refrigeration machine comprising a steam drain flow rate control valve provided between the branch section and the low-temperature drain cooler 11 and the drain bypass pipe . A high-temperature regenerator that separates the refrigerant vapor from the solution using the supplied vapor as a heating source, a low-temperature regenerator that separates the refrigerant vapor from the solution using the refrigerant vapor separated by the high-temperature regenerator, and the low-temperature regenerator A condenser that liquefies the separated refrigerant vapor, an evaporator that converts the refrigerant liquefied by the condenser into vapor, an absorber that absorbs the refrigerant vapor generated in the evaporator into the solution, and a rare solution that absorbs the refrigerant vapor A dilute solution pipe from the absorber to the high temperature regenerator and the low temperature regenerator, and a concentrated solution obtained by separating and concentrating the refrigerant vapor in the high temperature regenerator and the low temperature regenerator to the absorber. A concentrated solution pipe, a low temperature solution heat exchanger and a high temperature solution heat exchanger for exchanging heat between the diluted solution flowing through the diluted solution pipe and the concentrated solution flowing through the concentrated solution pipe, and steam drain discharged from the high temperature regenerator Flow And drain pipe, in the vapor absorption refrigerator comprising Dorenkura for cooling the steam drain provided in the drain pipe,
A bypass pipe branched from the upstream side of the low-temperature solution heat exchanger in the diluted solution pipe and connected to the diluted solution pipe on the downstream side of the low-temperature solution heat exchanger is provided, and the drain cooler is connected to the rare pipe from the bypass pipe. While configured to exchange heat between the solution and the steam drain from the drain pipe,
A flow control valve for a rare solution provided in the bypass pipe upstream of the drain cooler;
A temperature detector provided in the drain pipe for detecting the temperature of the steam drain;
A control device for controlling the temperature of the drain discharged by adjusting the flow rate of the rare solution flowing through the bypass pipe according to the temperature of the steam drain detected by the temperature detector ;
The drain cooler includes a low-temperature drain cooler disposed on the downstream side of the drain pipe and a high-temperature drain cooler disposed on the upstream side of the drain pipe, and the low-temperature drain cooler bypasses the low-temperature solution heat exchanger. The dilute solution flowing through the bypass pipe branched from the dilute solution pipe is configured to exchange heat with the steam drain, and the high temperature drain cooler is branched from the dilute solution pipe to bypass the high temperature solution heat exchanger. The dilute solution flowing through the bypass pipe and the steam drain are configured to exchange heat,
A drain bypass pipe that connects a drain pipe between the low temperature drain cooler and the high temperature drain cooler and a drain pipe downstream of the low temperature drain cooler so as to bypass the drain cooler, and the drain bypass pipe of the drain pipe; A steam absorption refrigeration machine comprising a steam drain flow rate control valve provided between the branch section and the low-temperature drain cooler 11 and the drain bypass pipe .   3. The steam absorption refrigerator according to claim 1, wherein a downstream side of the drain cooler of the bypass pipe branches from a rare solution pipe between the low temperature solution heat exchanger and the high temperature solution heat exchanger, and the low temperature A vapor absorption refrigerator that is connected to a branch pipe connected to a regenerator.   The steam absorption refrigerator according to claim 1 or 2, wherein a downstream side of the drain cooler of the bypass pipe is connected to a rare solution pipe between the low temperature solution heat exchanger and the high temperature solution heat exchanger. Vapor absorption refrigerator characterized by. 5. The vapor absorption refrigerator according to claim 4, wherein a downstream side of the drain cooler of the bypass pipe is a dilute solution pipe between the low temperature solution heat exchanger and the high temperature solution heat exchanger and from the dilute solution pipe. A steam absorption refrigerator, wherein a branch pipe that branches and is connected to the low-temperature regenerator is connected upstream of a branching portion. The vapor absorption refrigerator according to any one of claims 1 to 5 , wherein the temperature detector is provided in the drain pipe upstream of the low-temperature drain cooler. The vapor absorption refrigerator according to any one of claims 1 to 5 , wherein the temperature detector is provided in the drain pipe downstream of the low-temperature drain cooler. The vapor absorption refrigerator according to any one of claims 1 to 5 , wherein the temperature detector is provided in the drain pipe between the low temperature drain cooler and the high temperature drain cooler. refrigerator. The steam absorption refrigerator according to any one of claims 1 to 8 , wherein steam from a boiler is supplied to the high temperature regenerator, and the steam drain discharged from the high temperature regenerator has a temperature of 90 to 55 ° C by a drain cooler. The steam absorption refrigerator is configured to be cooled and cooled and then flowed into a drain tank that is open to the atmosphere, and is supplied to the boiler again from the drain tank by a drain pump. . The steam absorption refrigerator according to claim 9 , wherein the steam drain discharged from the high-temperature regenerator is cooled to a temperature of 90 to 80 ° C by a drain cooler and circulated, and then flows into the drain tank. A vapor absorption refrigerator characterized by being made.

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