Boiler blow-off waste heat utilization system

Abstract

The utility model discloses a boiler blow-off waste heat utilization system which comprises a continuous blow-off flash tank, a heat exchanger and a periodic blow-off flash tank which are sequentially communicated through pipelines, and the continuous blow-off flash tank is communicated with a boiler continuous blow-off pipeline through a pipeline. The periodic blowdown flash tank is communicated with a boiler periodic blowdown pipeline through a pipeline, the steam output end of the continuous blowdown flash tank is communicated with a low-pressure steam pipe network, the inlet end of a heat exchange pipeline of the heat exchanger is communicated with a water supply pipeline, and the outlet end of the heat exchange pipeline of the heat exchanger is communicated with a hot water outlet pipeline. And a spray cooling pipeline is arranged in the periodic blowdown flash tank and is communicated with an industrial cooling water input pipe network. The heat exchanger is arranged to recover the heat energy of the sewage water, so that the energy waste is reduced; the heat exchanger adopts the thin-wall spiral grooved tube, so that the heat exchange efficiency is improved, and the steel consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of boilers, in particular to a boiler sewage waste heat utilization system. Background Art

[0002] A boiler is an energy conversion device that uses the heat energy of fuel combustion or other heat energy such as waste heat flue gas to heat working water or other fluids to certain parameters. Boilers are widely used in power generation, industrial production, heating and other fields. Due to the continuous separation of steam and water in the drum, the salt in the boiler water continues to accumulate, and the quality of boiler water and steam gradually decreases, which leads to salt scaling on the heated area and even pipe burst accidents. In order to control the quality of boiler water and ensure the safe and stable operation of the boiler, the boiler user should discharge sewage continuously and regularly according to the quality of boiler water.

[0003] Continuous sewage is saturated water under drum pressure, with high temperature and pressure, and a sewage discharge rate of about 2-5%. Continuous discharge causes certain heat loss and waste of water resources. At present, most enterprises have set up continuous sewage expansion tanks. After continuous sewage is expanded by hydrogen expansion and pressure reduction, part of the sewage is flashed into steam. This part of steam can be recovered to the user's low-pressure steam network, and the remaining continuous sewage is discharged to the sewage cooling pool or cooler, cooled by production water or circulating water, and then sent out for treatment through sewage pumps. When the pressure of the sewage expansion tank is determined, the flash steam recovery ratio decreases as the boiler pressure decreases. The steam recovery ratio of high-pressure boilers does not exceed 35%. The parameters of most domestic drum boilers are below high pressure. Due to the small proportion of recovered steam, there is a large waste of energy. Utility Model Content

[0004] In order to solve the above technical problems, the utility model designs a boiler waste heat utilization system.

[0005] The utility model adopts the following technical solutions:

[0006] A boiler blowdown waste heat utilization system comprises a continuous blowdown expansion tank, a heat exchanger and a periodic blowdown expansion tank, wherein the continuous blowdown expansion tank, the heat exchanger and the periodic blowdown expansion tank are connected in sequence through pipelines, the continuous blowdown expansion tank is connected to the boiler continuous blowdown pipeline through the pipeline, the periodic blowdown expansion tank is connected to the boiler periodic blowdown pipeline through the pipeline, the steam output end of the continuous blowdown expansion tank is connected to a low-pressure steam pipeline network, the inlet end of the heat exchange pipeline of the heat exchanger is connected to a water supply pipeline, and the outlet end is connected to a hot water outlet pipeline, the output end of the periodic blowdown expansion tank is connected to a water pool, a spray cooling pipeline is arranged in the periodic blowdown expansion tank, and the spray cooling pipeline is connected to an industrial cooling water input pipeline network.

[0007] Preferably, the continuous sewage expansion tank is connected to the heat exchanger through a continuous sewage outlet pipe, the heat exchanger is connected to the periodic sewage expansion tank through a heat exchanger outlet pipe, and a heat exchanger bypass pipe is installed between the continuous sewage outlet pipe and the heat exchanger outlet pipe.

[0008] Preferably, the heat exchanger is a tubular or plate type heat exchanger. The tubular heat exchanger uses a thin-walled spirally grooved tube.

[0009] Preferably, the heat exchanger outlet pipe is also connected to a cooling water output network via a connecting pipeline, and a pneumatic valve A is installed on the connecting pipeline.

[0010] Preferably, the continuous sewage expansion tank is connected to the periodic sewage expansion tank via a pipeline connected to a safety valve.

[0011] Preferably, the continuous sewage expansion container is provided with a thermometer, a pressure gauge, a local water level gauge and a remote water level gauge.

[0012] Preferably, a regulating valve group is provided on the outlet pipe of the heat exchanger, and the regulating valve group is interlocked with a remote water level gauge on the continuous sewage expansion tank.

[0013] Preferably, a remote temperature meter and a pneumatic valve B are provided on the outlet pipe of the heat exchanger, and the remote temperature meter is interlocked with the pneumatic valve A and the pneumatic valve B.

[0014] The beneficial effects of the utility model are as follows: (1) the utility model recovers the heat energy of sewage by setting a heat exchanger, thereby reducing energy waste; (2) the heat exchanger of the utility model adopts thin-walled spiral grooved tubes, which improves heat exchange efficiency and reduces steel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model;

[0016] In the figure: 1. Continuous sewage expansion tank, 2. Heat exchanger, 3. Periodic sewage expansion tank, 4. Continuous sewage outlet pipe, 5. Heat exchanger outlet pipe, 6. Heat exchanger bypass pipe, 7. Remote water level gauge, 8. Regulating valve group, 9. Safety valve, 10. Pneumatic valve A, 11. Pneumatic valve B, 12. Remote temperature instrument, 13. Thermometer, 14. Local water level gauge, 15. Pressure gauge, 16. Low-pressure steam pipeline, 17. Boiler continuous sewage pipeline, 18. Water supply pipeline, 19. Hot water outlet pipeline, 20. Boiler periodic sewage pipeline, 21. Industrial cooling water input pipeline, 22. Cooling water output pipeline, 23. Water tank. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0018] Example: Figure 1 As shown, a boiler waste heat utilization system includes a continuous blowdown expansion tank 1, a heat exchanger 2 and a periodic blowdown expansion tank 3, and the continuous blowdown expansion tank, the heat exchanger and the periodic blowdown expansion tank are connected in sequence through pipelines;

[0019] The continuous blowdown from the boiler enters the continuous blowdown expansion tank 1 through the boiler continuous blowdown pipeline 17, the steam after flash evaporation of the continuous blowdown goes to the low-pressure steam network 16, and the remaining water after flash evaporation enters the heat exchanger 2 through the continuous blowdown outlet pipe 4;

[0020] The water used for energy recovery enters the heat exchanger 2 through the water supply pipe 18, is heated, and then leads out of the heat exchanger to enter the hot water outlet pipe 19. The continuous sewage after heat exchange and cooling enters the cooling water output pipe network 22 or the regular sewage expansion tank 3 through the heat exchanger outlet pipe 5;

[0021] The sewage in the periodic sewage expansion tank 3 is cooled by spraying with industrial cooling water from the industrial cooling water input pipe network 21 and then discharged into the water pool 23 .

[0022] The continuous blowdown expansion tank 1 is provided with a safety valve 9, and the exhaust steam of the safety valve 9 enters the periodic blowdown expansion tank 3 for recycling.

[0023] The heat exchanger 2 can be a tube type or a plate type heat exchanger.

[0024] The continuous sewage expansion container 1 is provided with a thermometer 13, a pressure gauge 15, a local water level gauge 14 and a remote water level gauge 7.

[0025] The heat exchanger 2 is provided with a heat exchanger bypass pipe 6. When the heat exchanger 2 is overhauled, the sewage is led out through the heat exchanger bypass pipe 6, so that the heat exchanger 2 can be isolated and the system operation is not affected during the overhaul.

[0026] A regulating valve group 8 is provided on the heat exchanger outlet pipe 5, which can effectively control the liquid level of the continuous sewage expansion tank 1 by interlocking with the remote water level gauge 7 on the continuous sewage expansion tank 1 to ensure the safe and stable operation of the continuous sewage expansion tank 1.

[0027] The heat exchanger outlet pipe 5 is provided with a remote temperature transmitter 12, a pneumatic valve A10 and a pneumatic valve B11. The remote temperature transmitter 12 is interlocked with the valve. When the temperature is high, the pneumatic valve A10 is closed and the pneumatic valve B11 is opened to cut off the sewage entering the cooling water output pipe network 22 and introduce the sewage into the periodic sewage expansion tank 3.

[0028] When the boiler waste heat utilization system is in use, the wastewater from the continuous blowdown of the boiler enters the continuous blowdown expansion tank 1 and the remaining wastewater enters the heat exchanger 2 after flash evaporation, and the heat energy of the wastewater is recovered and utilized in the heat exchanger 2. The wastewater with recovered heat energy is discharged into the cooling water output pipeline 22 or the periodic blowdown expansion tank 3.

[0029] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A boiler waste heat utilization system, characterized in that: It includes a continuous sewage expansion tank, a heat exchanger and a periodic sewage expansion tank, which are connected in sequence through pipelines. The continuous sewage expansion tank is connected to the continuous sewage pipeline of the boiler through a pipeline, and the periodic sewage expansion tank is connected to the periodic sewage pipeline of the boiler through a pipeline. The steam output end of the continuous sewage expansion tank is connected to the low-pressure steam pipeline network, the inlet end of the heat exchange pipeline of the heat exchanger is connected to the water supply pipeline, and the outlet end is connected to the hot water outlet pipeline. The output end of the periodic sewage expansion tank is connected to a water pool, and a spray cooling pipeline is arranged in the periodic sewage expansion tank, and the spray cooling pipeline is connected to the industrial cooling water input pipeline network.

2. A boiler waste heat utilization system according to claim 1, characterized in that: The continuous sewage expansion tank is connected to the heat exchanger through the continuous sewage outlet pipe, and the heat exchanger is connected to the periodic sewage expansion tank through the heat exchanger outlet pipe. A heat exchanger bypass pipe is installed between the continuous sewage outlet pipe and the heat exchanger outlet pipe.

3. A boiler waste heat utilization system according to claim 1, characterized in that: The heat exchanger is a tube type or a plate type heat exchanger.

4. A boiler waste heat utilization system according to claim 2, characterized in that: The heat exchanger outlet pipeline is also connected to the cooling water output pipeline network through a connecting pipeline, and a pneumatic valve A is installed on the connecting pipeline.

5. The boiler waste heat utilization system according to claim 1 is characterized in that: The continuous sewage expansion tank is connected to the periodic sewage expansion tank through a pipeline connected with a safety valve.

6. A boiler waste heat utilization system according to claim 1, characterized in that: The continuous sewage expansion container is provided with a thermometer, a pressure gauge, an on-site water level gauge and a remote water level gauge.

7. The boiler waste heat utilization system according to claim 1 is characterized in that: The heat exchanger outlet pipeline is provided with a regulating valve group, which is interlocked with a remote water level gauge on the continuous sewage expansion tank.

8. A boiler waste heat utilization system according to claim 4, characterized in that: A remote temperature meter and a pneumatic valve B are provided on the outlet pipe of the heat exchanger, and the remote temperature meter is interlocked with the pneumatic valve A and the pneumatic valve B.

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