CN210035038U

CN210035038U - Trap cage for heater and step-by-step trap

Info

Publication number: CN210035038U
Application number: CN201920908682.4U
Authority: CN
Inventors: 王佑彬
Original assignee: Guodian Changyuan Jingzhou Thermal Power Co ltd
Current assignee: Guoneng Changyuan Jingzhou Thermal Power Co ltd
Priority date: 2019-06-17
Filing date: 2019-06-17
Publication date: 2020-02-07
Anticipated expiration: 2029-06-17

Abstract

The utility model provides a trap valve cage and step-by-step trap for heater, the trap valve cage includes the cylindric cage body, and cage body both ends are equipped with first opening and second opening respectively, and the lateral wall that is close to second opening one end of cage body is equipped with a plurality of first drainage holes, and a plurality of first drainage holes are arranged at a certain distance of interval in the cage body axial, and the aperture of a plurality of first drainage holes diminishes gradually as its distance with the second opening diminishes; the step-by-step drain valve comprises a valve body, a valve cover, a valve core mechanism, a valve seat, a valve rod and a drain valve cage, wherein the drain valve cage is positioned inside the valve body, and the valve seat is arranged at a second opening of the drain valve cage. The utility model can effectively avoid the overlarge water level fluctuation and ensure the stability of water level regulation by setting the first drain hole on the side wall of the valve cage into a gradually-changed structure and the smaller the diameter of the first drain hole at the position closer to the valve seat; when the load change is large and fast, the large flow water drainage quantity demand can be responded quickly.

Description

Trap cage for heater and step-by-step trap

Technical Field

The utility model relates to a pipeline valve field especially relates to a trap valve cage and trap step by step for heater.

Background

The high-low pressure heater is important equipment for improving the heat economy of a steam turbine in a thermal power plant, is a device for heating boiler feed water by using steam extracted by the steam turbine, is used for improving the thermal efficiency of the power plant and saving fuel, and is beneficial to the safe operation of a unit. The existing high-low heaters all adopt surface heaters, namely, cold water is in a channel in a pipeline, steam extraction and drainage are in a channel outside the pipeline, and the working principle is as follows: the superheated steam with higher temperature from the steam turbine enters from a steam port of the heater, first heat transfer is completed in a superheated steam cooling section, namely feed water (condensed water) leaving the section of the heater is heated by using the superheat degree of the steam, so that the temperature of a feed water (condensed water) outlet is further increased; then the steam enters a saturation section, and secondary heat transfer is carried out, namely the heating steam releases a large amount of latent heat again and is condensed into saturated hydrophobic water, and the saturated hydrophobic water is a main heat transfer area of the heater; the saturated hydrophobic water is gathered at the lower part of the device and enters the hydrophobic cooling section by the siphon principle under the action of pressure difference, the saturated hydrophobic water releases heat to heat the feed water (condensed water) which just enters the heater, the third heat transfer is completed, and finally the hydrophobic water becomes supercooled water and leaves the body through the hydrophobic outlet.

The step-by-step drain valve is an important safety component for reasonably improving the energy utilization efficiency of the steam turbine heater, because if the high-low pressure heater runs at too high/too low water level, the high-low pressure heater can be damaged, and even threatens the safety of a steam turbine host (steam turbine water impact accident), so that the water level in the heater needs to be controlled by the step-by-step drain valve to avoid the accidents such as water inlet of the steam turbine and the like. Because the drain holes on the traditional drain valve cage are arranged in equal diameter and are uniformly arranged at the lower end of the side wall of the cage, the condensed drain quantity in the heater is small or even too small at the degassing stage of the operation of the heater and the low load stage of the unit, the opening degree of the drain valve is required to be kept small, and the water level fluctuation in the heater is easy to be large due to the arrangement of the equal-diameter drain holes, so that the water level regulation stability of the drain valve is poor; in addition, under the AGC (Automatic generation control) working condition, the heater has a large and fast load change and large fluctuation of the water discharge amount, which also results in poor stability of water level adjustment.

SUMMERY OF THE UTILITY MODEL

To exist not enough among the prior art, the utility model provides a drain valve cage and step by step drain valve for heater, it has solved the poor problem of water level control stability that medium aperture drain valve cage of prior art exists.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a trap valve cage for heater, it includes cylindric cage body, the both ends of the cage body are equipped with first opening and second opening respectively, the lateral wall that is close to second opening one end of the cage body is equipped with a plurality of first hydrophobic holes, wherein: the plurality of first water-drainage holes are arranged at intervals in the axial direction of the cage body, and the aperture diameters of the plurality of first water-drainage holes are gradually reduced as the distance between the plurality of first water-drainage holes and the second opening is reduced.

Furthermore, the utility model also provides a trap step by step for the heater, it includes valve body, valve gap, case mechanism, disk seat and valve rod, wherein: the valve core mechanism and the valve seat are arranged inside the valve body, the valve rod extends into the valve body from the outside of the valve cover and is connected with the valve core mechanism, the step-by-step drain valve further comprises a drain valve cage, the drain valve cage is located inside the valve body, the valve seat is installed at a second opening of the drain valve cage, and the valve core mechanism is located inside the drain valve cage.

Compared with the prior art, the utility model discloses following beneficial effect has: at the initial stage of the step-by-step drain valve operation and the low load stage of the unit, the water level of the condensed water is lower and the drainage quantity is less, and even if the opening degree of the valve is larger, the first drain hole on the side wall of the valve cage is arranged in a gradual change manner, and the aperture of the first drain hole is smaller closer to the valve seat, so that the overlarge fluctuation of the water level can be effectively avoided, and the stability of water level adjustment is ensured; meanwhile, under the AGC working condition that the load change is large and fast, the aperture of the first drainage hole far away from the valve seat is gradually increased, and the large-flow drainage quantity requirement can be quickly responded by the small valve opening change.

Drawings

FIG. 1 is a schematic diagram of the trap cage of the present invention.

FIG. 2 is a schematic side view of the trap cage of the present invention.

Fig. 3 is a schematic structural view of the step-by-step trap of the present invention.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings and embodiments.

As shown in fig. 1, the utility model provides a trap valve cage 10 for heater, including cylindric cage body 101, the both ends of cage body 101 are equipped with first opening 102 and second opening 103 respectively, the lateral wall that is close to second opening 103 one end of cage body 101 is equipped with a plurality of first hydrophobic holes 104, the lateral wall that is close to first opening 102 one end of cage body 101 still is equipped with balancing hole 105, wherein:

as shown in fig. 2, a plurality of the first water-repellent holes 104 are arranged at a certain distance in the axial direction of the cage 101, and the hole diameters of the plurality of first water-repellent holes 104 gradually decrease as the distance from the second opening 103 decreases; specifically, the first water drainage holes 104 are uniformly divided into a plurality of groups, each group of the first water drainage holes 104 is uniformly distributed circumferentially around the central axis of the cage 101, and the first water drainage holes 104 included in each group of the first water drainage holes 104 are further arranged in a staggered manner in the radial direction of the cage 101, so that each group of the first water drainage holes 104 are spirally arranged on the side wall of the cage 101; preferably, the number of the first water drainage holes 104 is six, and each group of the first water drainage holes 104 are circumferentially distributed on the side wall of the cage 101 at intervals of 60 ° in sequence, and the number of the first water drainage holes 104 in each group is 10;

the side wall of the cage body 101 is further provided with a plurality of second drainage holes 106, the distance between each of the plurality of second drainage holes 106 and the corresponding second opening 103 is greater than the distance between each of the first drainage holes 104 and the corresponding second opening 103, specifically, the number of the second drainage holes 106 is six, each group of the second drainage holes 106 is three, and each group of the second drainage holes 106 is located between two adjacent groups of the first drainage holes 104, so that the drainage area in the middle of the cage body 101 is further increased on the premise that the area of each first drainage hole 104 is not increased, the effect of further accelerating response to large-flow condensed water is facilitated, and the condensed water caused by the fact that the water level is too high and cannot be timely released is avoided;

the side wall of the cage body 101 close to one end of the second opening 103 is further provided with a plurality of third hydrophobic holes 107, the distance between the third hydrophobic holes 107 and the second opening 103 is smaller than the distance between the first hydrophobic holes 104 and the second opening 103, and the aperture of the third hydrophobic holes 107 is larger than the aperture of the smallest first hydrophobic hole 104 and smaller than the aperture of the largest first hydrophobic hole 104; specifically, the third drainage holes 107 are reserved and respectively arranged on the extension line of each group of the first drainage holes 104, and are used for meeting the drainage speed of the valve at a smaller opening degree, so as to avoid the problems of co-flow of steam and water and reduction of effective drainage amount caused by too low water level and larger opening degree of the valve.

In addition, the present invention further provides a step-by-step drain valve for a heater, as shown in fig. 3, which comprises a valve body 20, a valve cover 30, a valve core mechanism, a valve seat 40, a valve rod 50 and the drain valve cage 10, wherein the valve body 20 is internally provided with a valve cavity 201 for installing the drain valve cage 10, and a water inlet channel 202 and a water outlet channel 203 which are respectively communicated with the valve cavity 201, the valve cover 30 is installed outside the valve body 20 and is used for sealing an opening of the valve cavity 201, the valve seat 40 is installed in the position of the valve cavity 201 close to the water outlet channel 203, the valve core mechanism and the valve seat 40 are both arranged inside the valve body 20, the valve rod 50 extends into the valve body 20 from the outside of the valve cover 30 and is connected with the valve core mechanism, the drain valve cage 10 is located in the valve cavity 201, and a second opening 103 of the drain valve cage is matched with the valve seat, the valve core mechanism comprises a valve clack 60 and a pre-opening valve 70 installed in the valve clack 60, specifically, a through hole 601 for installing the pre-opening valve 70 and allowing a medium to pass through is formed in the center of the valve clack 60, the pre-opening valve 70 is limited in the through hole 601 through a locking piece 80, and the lower end of the valve rod 50 penetrates through the locking piece 80 and is connected with the pre-opening valve 70. As shown in fig. 3, before the external actuator drives the flap 60 to move through the valve rod 50, the pre-open valve 70 is driven to move, so that a small amount of medium, such as condensed water, enters the outlet flow channel 203 through the balance hole 105 and the through hole 601, thereby achieving pressure balance on both sides of the flap 60; after that, the actuator continues to work, that is, the valve rod 50 drives the valve flap 60 to move, and then the water inlet channel 202 and the water outlet channel 203 are communicated through the third water drainage hole 107, the first water drainage hole 104 and the second water drainage hole 106. Because the first water drainage hole 104 close to the valve seat 40 has a smaller aperture, when the water level of the condensed water is lower and the drainage quantity is small, even if the opening degree of the valve clack 60 is larger, the water level fluctuation can be effectively avoided from being too large; when the water level of the condensed water is high, the valve clack 60 moves to the position above the second drain hole 106, so that all the drain holes are opened, the high-flow drain quantity can be quickly responded, and the steam turbine water impact accident caused by the backflow of the condensed water is avoided.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or replaced by other means without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims.

Claims

1. A trap valve cage for heater, including the cylindric cage body, the both ends of the cage body are equipped with first opening and second opening respectively, the lateral wall that is close to second opening one end of the cage body is equipped with a plurality of first hydrophobic holes, its characterized in that: the plurality of first water-drainage holes are arranged at intervals in the axial direction of the cage body, and the aperture diameters of the plurality of first water-drainage holes are gradually reduced as the distance between the plurality of first water-drainage holes and the second opening is reduced.

2. A trap cage for a heater as defined in claim 1 wherein: the first drain holes are evenly divided into a plurality of groups, the first drain holes of each group are evenly distributed in a circumferential mode around the central axis of the cage body, and the first drain holes of each group are arranged in a staggered mode in the radial direction of the cage body.

3. A trap cage for a heater as defined in claim 1 wherein: the lateral wall of the cage body is also provided with a plurality of second hydrophobic holes, and the distance between the second hydrophobic holes and the second opening is larger than the distance between the first hydrophobic holes and the second opening.

4. A trap cage for a heater as defined in claim 1 wherein: the lateral wall of the cage body close to one end of the second opening is also provided with a plurality of third hydrophobic holes, the distance between the third hydrophobic holes and the second opening is smaller than the distance between the first hydrophobic holes and the second opening, and the aperture of the third hydrophobic holes is larger than that of the minimum first hydrophobic holes and smaller than that of the maximum first hydrophobic holes.

5. The trap cage for a heater of any one of claims 1-4 wherein: the side wall of the cage body close to one end of the first opening is also provided with a balance hole.

6. A trap step by step for heater, it includes valve body, valve gap, case mechanism, disk seat and valve rod, wherein case mechanism and disk seat all set up inside the valve body, the valve rod extends to in the valve body and is connected its characterized in that with case mechanism from the valve gap outside: the trap of claim 1 further comprising a trap cage positioned within the valve body, the valve seat positioned at the second opening of the trap cage, and the poppet mechanism positioned within the trap cage.

7. The progressive drain valve for a heater of claim 6, wherein: the valve core mechanism comprises a valve clack and a pre-starting valve arranged in the valve clack, and the valve rod is connected with the pre-starting valve.