Low-temperature economizer for waste heat recovery of thermal power plant

Abstract

The utility model relates to the technical field of environmental protection and energy conservation, in particular to a low-temperature economizer for waste heat recovery of a thermal power plant. The device comprises a connecting pipe, a water inlet pipe is installed on one side of the connecting pipe, a water inlet pipe is installed on one side of the water inlet pipe, the side, away from the connecting pipe, of the water inlet pipe is communicated and connected with a water inlet collecting box, and one side of the water inlet collecting box is communicated and connected with a top steam-water heat exchanger. One side of the top steam-water heat exchanger is communicated and connected with a water outlet collecting box, one side of the water outlet collecting box is communicated and connected with a water outlet pipe, and water collecting grooves are formed in the sides, close to each other, of the water inlet pipe and the water outlet pipe. And heat medium water in the heat medium water tank leaks, so that the phenomenon that dust is seriously accumulated on the surface of the wide-channel plate heat exchanger is caused, and the low-temperature economizer cannot operate normally is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection and energy saving, in particular to a low-temperature economizer for recovering waste heat from a thermal power plant. Background Art

[0002] Low-temperature economizer is a device that can effectively save coal and improve boiler efficiency in the low-temperature section. It is mainly used in the medium and low-temperature sections of the air preheater outlet of large boilers in power plants, thermal power plants, etc. It can effectively reduce the exhaust gas thermal efficiency by recovering the flue gas waste heat to heat the boiler feed water. Low-temperature economizer is usually installed in the tail flue at the outlet of the boiler air preheater. It can not only improve the efficiency of electrostatic precipitator and meet low emission requirements, but also reduce power consumption and reduce the specifications of downstream equipment. At the same time, it can remove most of the acid gases.

[0003] A Chinese patent application CN202021324151.X discloses a control system for automatically removing slag from a flue gas low-temperature economizer. The key points of its technical solution are: it includes a flue network, a slag scraper, a slag discharger, a control system and an economizer. The two sides of the economizer are connected to the flue network respectively. The slag scraper is arranged inside the flue network, and a slag discharger is arranged at the bottom of the flue network. The utility model can avoid the blockage of the economizer by slag, so that the fin spacing of the original finned tube of the flue gas low-temperature economizer can be reduced to recover more waste heat, or a plate economizer with better waste heat recovery effect can be used. The economizer has a wider range of indications and achieves a higher waste heat recovery effect.

[0004] In view of the above-mentioned and existing related technologies, the inventors believe that the following defects often exist: the heat medium water in the heat medium water tank is directly introduced into the wide channel plate heat exchanger. After the wide channel plate heat exchanger is worn, the heat medium water in the heat medium water tank will leak, resulting in serious dust accumulation on the surface of the wide channel plate heat exchanger, thereby causing the low-temperature economizer to fail to operate normally; therefore, in view of the above-mentioned problems, a low-temperature economizer for waste heat recovery in a thermal power plant is proposed. Utility Model Content

[0005] The purpose of the utility model is to solve the problem in the prior art that the heat medium water in the heat medium water tank is directly introduced into the wide channel plate heat exchanger. After the wide channel plate heat exchanger is worn, the heat medium water in the heat medium water tank will leak, resulting in serious dust accumulation on the surface of the wide channel plate heat exchanger, thereby causing the low-temperature economizer to fail to operate normally. A low-temperature economizer for waste heat recovery in a thermal power plant is proposed.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a low-temperature economizer for waste heat recovery in a thermal power plant, comprising a connecting pipe, a water inlet pipe is installed on one side of the connecting pipe, a water inlet pipe is installed on one side of the water inlet pipe, a side of the water inlet pipe away from the connecting pipe is connected to a water inlet header, a side of the water inlet header is connected to a top steam-water heat exchanger, a side of the top steam-water heat exchanger is connected to a water outlet header, a side of the water outlet header is connected to a water outlet pipe, a water collecting trough is installed on the side where the water inlet pipe and the water outlet pipe are close to each other, the water inlet header and the water outlet header are both installed inside the water collecting trough, the top steam-water heat exchanger is located in the inner cavity of the water collecting trough, the lower surface of the water collecting trough is connected to a downcomer, the end of the downcomer away from the water collecting trough is connected to a heat medium water tank, a plurality of wide channel plate heat exchangers are installed in the inner cavity of the water collecting trough, and the other side of the wide channel plate heat exchanger is fixedly installed in the inner cavity of the heat medium water tank.

[0007] The effect achieved by the above components is: through the above series of devices, the effect of zero leakage of condensed water inside the water collecting tank is achieved, which avoids the heat medium water in the heat medium water tank from directly entering the wide channel plate heat exchanger. After the wide channel plate heat exchanger is worn, the heat medium water in the heat medium water tank will leak, resulting in serious dust accumulation on the surface of the wide channel plate heat exchanger, thereby causing the low-temperature economizer to fail to operate normally, thereby improving the practicability of the device.

[0008] Preferably, six downcomers are provided, three downcomers form a group, and two groups of downcomers are symmetrically distributed.

[0009] The effects achieved by the above components are: saving the energy consumption required for the heat medium water circulation and improving the practicability of the device.

[0010] Preferably, the surface of the water inlet pipe is provided with a groove, the inner surface of the groove of the water inlet pipe is slidably connected with a clamping tube, the clamping tube is fixedly connected to the surface of the connecting pipe, the surface of the connecting pipe is fixedly connected with two clamping plates, the surfaces of the two clamping plates are both slidably connected to the water inlet pipe, a fixing hole is provided on the surface of the clamping plate, the inner surface of the fixing hole of the clamping plate is slidably connected with a sliding rod, the arc surface of the sliding rod is slidably connected with an L-shaped plate, the L-shaped plate is fixedly connected to the arc surface of the water inlet pipe, one end of the sliding rod is fixedly connected with a pull plate, and the surface of the connecting pipe is fixedly connected with a sealing gasket.

[0011] The effect achieved by the above components is: the effect of quick installation or removal of the connecting pipe and the water inlet pipe is achieved, and the connection between the connecting pipe and the water inlet pipe is avoided. The bolts will be corroded in this environment, affecting the installation or removal between the connecting pipe and the water inlet pipe.

[0012] Preferably, the arc surface of the sliding rod is sleeved with a spring, and two ends of the spring are fixedly connected to the L-shaped plate and the pulling plate respectively.

[0013] The effect achieved by the above components is that under the action of the spring, the sliding rod is automatically ejected into the fixing hole of the clamping plate, thereby improving the practicability of the device.

[0014] Preferably, a limiting groove is provided on the arc surface of the sliding rod, a limiting rod is slidably inserted into the L-shaped plate, and the arc surface of the limiting rod is slidably connected to the inner surface of the limiting groove of the sliding rod.

[0015] The effects achieved by the above components are: achieving the effect of limiting the stretched sliding rod, making it convenient for workers to install the connecting pipe and the water inlet pipe, and improving the practicability of the device.

[0016] Preferably, four legs are fixedly connected to the lower surface of the heat medium water tank, and one end of the leg away from the heat medium water tank is fixedly connected to a support plate.

[0017] The effects achieved by the above components are: achieving the effect of supporting the heat medium water tank, avoiding corrosion of the heat medium water tank, and improving the practicability of the device.

[0018] In summary, the beneficial effects of the utility model are:

[0019] In the utility model, the effect of zero leakage of condensed water inside the water collecting tank is achieved, and the heat medium water in the heat medium water tank is avoided from directly entering the wide channel plate heat exchanger. After the wide channel plate heat exchanger is worn, the heat medium water in the heat medium water tank will leak, resulting in serious dust accumulation on the surface of the wide channel plate heat exchanger, thereby causing the low-temperature economizer to be unable to operate, thereby improving the practicability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0021] Figure 2 It is a partial structural schematic diagram of the utility model;

[0022] Figure 3 It is a structural schematic diagram of the connecting pipe in the utility model;

[0023] Figure 4 For the utility model Figure 3 Enlarged view of point A.

[0024] Legend: 1. Connecting pipe; 2. Water inlet pipe; 3. Water outlet pipe; 4. Water inlet header; 5. Water outlet header; 6. Top steam-water heat exchanger; 7. Wide-channel plate heat exchanger; 8. Heat medium water tank; 9. Downcomer; 10. Water collecting trough; 11. Leg; 12. Support plate; 13. Clamping tube; 14. Clamping plate; 15. Sliding rod; 16. L-shaped plate; 17. Pull plate; 18. Spring; 19. Limit rod; 20. Sealing gasket. DETAILED DESCRIPTION

[0025] Reference Figure 1-Figure 4As shown, the utility model provides a technical solution: a low-temperature economizer for waste heat recovery in a thermal power plant, comprising a connecting pipe 1, a water inlet pipe 2 is installed on one side of the connecting pipe 1, a water inlet pipe 2 is installed on one side of the water inlet pipe 2, a side of the water inlet pipe 2 away from the connecting pipe 1 is connected to a water inlet header 4, a side of the water inlet header 4 is connected to a top steam-water heat exchanger 6, a side of the top steam-water heat exchanger 6 is connected to a water outlet header 5, a side of the water outlet header 5 is connected to a water outlet pipe 3, a water collecting trough 10 is installed on the side where the water inlet pipe 2 and the water outlet pipe 3 are close to each other, the water inlet header 4 and the water outlet header 5 are both installed inside the water collecting trough 10, the top steam-water heat exchanger 6 is located in the inner cavity of the water collecting trough 10, the lower surface of the water collecting trough 10 is connected to a downcomer 9, and the downcomer 9 is far away from the connecting pipe 1. One end of the water collecting tank 10 is connected to a heat medium water tank 8, and a plurality of wide channel plate heat exchangers 7 are installed in the inner cavity of the water collecting tank 10. The other side of the wide channel plate heat exchanger 7 is fixedly installed in the inner cavity of the heat medium water tank 8. Through the above series of devices, the effect of zero leakage of condensed water inside the water collecting tank 10 is achieved, and the heat medium water in the heat medium water tank 8 is avoided from directly entering the wide channel plate heat exchanger 7. After the wide channel plate heat exchanger 7 is worn, the heat medium water in the heat medium water tank 8 will leak, resulting in serious dust accumulation on the surface of the wide channel plate heat exchanger 7, thereby causing the low-temperature economizer to be unable to operate, thereby improving the practicability of the device, and the spacing between the plurality of wide channel plate heat exchangers 7 is large, and the large spacing between the wide channel plate heat exchangers 7 can It is ensured that the surface of the wide channel plate heat exchanger 7 is not easy to accumulate dust, and the service life of the wide channel plate heat exchanger 7 is increased. The downcomers 9 are arranged in six, and three downcomers 9 form a group. The two groups of downcomers 9 are symmetrically distributed, which saves the energy consumption required for the circulation of heat medium water and improves the practicality of the device. A groove is provided on the surface of the water inlet pipe 2, and the inner surface of the groove of the water inlet pipe 2 is slidably connected with a clamping tube 13, and the clamping tube 13 is fixedly connected to the surface of the connecting pipe 1. The surface of the connecting pipe 1 is fixedly connected with two clamping plates 14, and the surfaces of the two clamping plates 14 are both slidably connected to the water inlet pipe 2. A fixing hole is provided on the surface of the clamping plate 14, and the inner surface of the fixing hole of the clamping plate 14 is slidably connected with a sliding rod 15, and the arc surface of the sliding rod 15 is slidably connected with an L-shaped plate 16, and the L-shaped plate 16 is connected to the inlet pipe 2. The arc surface of the water pipe 2 is fixedly connected, one end of the sliding rod 15 is fixedly connected with a pull plate 17, and the surface of the connecting pipe 1 is fixedly connected with a sealing gasket 20, so that the connecting pipe 1 and the water inlet pipe 2 can be quickly installed or disassembled, and the connection between the connecting pipe 1 and the water inlet pipe 2 is avoided. The bolt connection, which will be corroded in this environment, affects the installation or disassembly between the connecting pipe 1 and the water inlet pipe 2. The arc surface of the sliding rod 15 is sleeved with a spring 18, and the two ends of the spring 18 are respectively fixedly connected to the L-shaped plate 16 and the pull plate 17. Under the action of the spring 18, the sliding rod 15 is automatically ejected into the fixing hole of the clamping plate 14, which improves the practicability of the device. The arc surface of the sliding rod 15 is provided with a limiting groove, and a limiting rod 19 is slidably inserted in the L-shaped plate 16.The arc surface of the limit rod 19 is slidably connected with the inner surface of the limit groove of the sliding rod 15, achieving the effect of limiting the stretched sliding rod 15, which is convenient for the staff to install the connecting pipe 1 and the water inlet pipe 2, and improves the practicality of the device. The lower surface of the heat medium water tank 8 is fixedly connected with four legs 11, and the end of the leg 11 away from the heat medium water tank 8 is fixedly connected with a support plate 12, achieving the effect of supporting the heat medium water tank 8, avoiding the corrosion of the heat medium water tank 8, and improving the practicality of the device.

[0026] Working principle, step one: the waste heat flue gas at the outlet of the air preheater passes through the wide channel heat exchange plate to transfer the waste heat to the heat exchange plate, step two: heat medium self-circulation system: ① After the heat medium water is heat exchanged in the wide channel plate heat exchanger 7, it becomes a steam-water mixture and rises until it becomes water vapor and enters the water collecting tank 10; ② The water vapor is condensed after heat exchange with the top steam-water heat exchanger 6, and the water vapor becomes condensed water droplets and gathers inside the water collecting tank 10; ③ The heat medium water in the water collecting tank 10 utilizes the density difference and flows back to the bottom header through the gravity of the downcomer 9; ④ The water in the heat medium water tank 8 utilizes the density difference between the downcomer 9 and the hot plate, and at the same time utilizes the rising force of the hot plate bubbles and part of the capillary condensation liquid film force to enter the heat exchange plate for heating, and the heat medium water forms a cycle.

[0027] When the staff needs to connect the connecting pipe 1 with the water inlet pipe 2, the staff pushes the connecting pipe 1, and the connecting pipe 1 drives the clamping tube 13 to slide into the groove of the water inlet pipe 2, and the clamping plate 14 on the connecting pipe 1 slides into the water inlet pipe 1, and the clamping plate 14 drives the sliding rod 15 to slide in the L-shaped plate 16, and the sliding rod 15 drives the spring 18 to stretch. When the sealing gasket 20 on the connecting pipe 1 fits with the surface of the water inlet pipe 2, the fixing hole of the clamping plate 14 and the sliding rod 15 are at the same level, and the sliding rod 15 automatically bounces into the fixing hole of the clamping plate 14 under the action of the spring 18, so that the effect of quick installation or disassembly of the connecting pipe 1 and the water inlet pipe 2 is achieved, and the connection between the connecting pipe 1 and the water inlet pipe 2 is avoided. The bolt connection, which will be corroded in this environment, affects the installation or disassembly between the connecting pipe 1 and the water inlet pipe 2.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

Claims

1. A low-temperature economizer for waste heat recovery in a thermal power plant, comprising a connecting pipe (1), characterized in that: A water inlet pipe (2) is installed on one side of the connecting pipe (1), a water inlet pipe (2) is installed on one side of the water inlet pipe (2), a side of the water inlet pipe (2) away from the connecting pipe (1) is connected to a water inlet header (4), a side of the water inlet header (4) is connected to a top steam-water heat exchanger (6), a side of the top steam-water heat exchanger (6) is connected to a water outlet header (5), a side of the water outlet header (5) is connected to a water outlet pipe (3), and a water collecting tank is installed on the side of the water inlet pipe (2) and the water outlet pipe (3) close to each other. (10), the water inlet header (4) and the water outlet header (5) are both installed inside the water collecting tank (10), the top steam-water heat exchanger (6) is located in the inner cavity of the water collecting tank (10), the lower surface of the water collecting tank (10) is connected to a downcomer (9), and the end of the downcomer (9) away from the water collecting tank (10) is connected to a heat medium water tank (8), and the inner cavity of the water collecting tank (10) is installed with a plurality of wide channel plate heat exchangers (7), and the other side of the wide channel plate heat exchanger (7) is fixedly installed in the inner cavity of the heat medium water tank (8).

2. The low-temperature economizer for waste heat recovery in a thermal power plant according to claim 1, characterized in that: The number of the downcomers (9) is six, three of the downcomers (9) form a group, and two groups of downcomers (9) are symmetrically distributed.

3. The low-temperature economizer for waste heat recovery in a thermal power plant according to claim 1, characterized in that: The surface of the water inlet pipe (2) is provided with a groove, the inner surface of the groove of the water inlet pipe (2) is slidably connected with a clamping tube (13), the clamping tube (13) is fixedly connected to the surface of the connecting pipe (1), the surface of the connecting pipe (1) is fixedly connected with two clamping plates (14), the surfaces of the two clamping plates (14) are both slidably connected to the water inlet pipe (2), the surface of the clamping plates (14) is provided with a fixing hole, the inner surface of the fixing hole of the clamping plate (14) is slidably connected with a sliding rod (15), the circular arc surface of the sliding rod (15) is slidably connected with an L-shaped plate (16), the L-shaped plate (16) is fixedly connected to the circular arc surface of the water inlet pipe (2), one end of the sliding rod (15) is fixedly connected with a pull plate (17), and the surface of the connecting pipe (1) is fixedly connected with a sealing gasket (20).

4. The low-temperature economizer for waste heat recovery in a thermal power plant according to claim 3, characterized in that: The arc surface of the sliding rod (15) is sleeved with a spring (18), and the two ends of the spring (18) are respectively fixedly connected to the L-shaped plate (16) and the pulling plate (17).

5. The low-temperature economizer for waste heat recovery in a thermal power plant according to claim 3, characterized in that: The arc surface of the sliding rod (15) is provided with a limiting groove, a limiting rod (19) is slidably inserted in the L-shaped plate (16), and the arc surface of the limiting rod (19) is slidably connected to the inner surface of the limiting groove of the sliding rod (15).

6. The low-temperature economizer for waste heat recovery in a thermal power plant according to claim 1, characterized in that: Four legs (11) are fixedly connected to the lower surface of the heat medium water tank (8), and one end of the legs (11) away from the heat medium water tank (8) is fixedly connected to a support plate (12).

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