Condensate water system heated by using subcritical boiler flue waste heat

Abstract

The utility model belongs to the technical field of subcritical boilers, and relates to a condensation water system utilizing subcritical boiler flue waste heat to heat, which comprises a cooling water tank, a connecting pipe is arranged at the front end of the cooling water tank, the connecting pipe is connected to a heat exchanger, the heat exchanger is arranged in a boiler flue, and a water inlet pipe is led out of the heat exchanger. A water conduit is arranged at the top of the cooling water tank and connected to a water return pipe, the water return pipe is connected to the circulating water tank, the circulating water tank is provided with a water outlet pipe, and a water drainage pipe is arranged on one side of the cooling water tank and connected to the deaerator. Condensed water can be heated through subcritical boiler flue waste heat, the waste heat can be recycled, the steelmaking steam yield is increased, the power generation power is improved, meanwhile, after the exhaust gas temperature is reduced, the smoke volume is reduced, and the power consumption of an induced draft fan is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of subcritical boilers, and in particular relates to a condensate system heated by utilizing flue waste heat of a subcritical boiler. Background Art

[0002] Subcritical gas-fired boilers use blast furnace gas and converter gas. The heat released by combustion in the boiler heats the feed water sent by the steam turbine into superheated steam, and the high-pressure cylinder exhaust steam is heated into reheated steam for use by the steam turbine. The steam source of the saturated steam generator set includes the steam produced by the steam generation and cooling of the converter in the plant area and the steam produced by the steam generation and cooling of the heating furnace. The condensed water is sent to the water tanks in the converter and heating furnace area of ​​the plant area, and is pumped to the deaerator through the desalting pump.

[0003] When designing the subcritical boiler, the proportion of gaseous water was not considered in the coal gas. After sampling and testing, the volume ratio of water vapor in the coal gas was 15%. As a result, the average daily exhaust temperature of 160℃ was 20℃ higher than the designed 140℃, and the heat loss of the exhaust gas increased. It was calculated that the subcritical unit needed to consume more coal gas. In addition, due to the increase in coal gas consumption, the amount of air and flue gas increased simultaneously, and the power consumption of the induced draft fan increased accordingly, which greatly reduced the unit efficiency. Utility Model Content

[0004] The utility model aims to provide a condensate system heated by using the waste heat of the subcritical boiler flue, which has the function of heating the condensate by using the waste heat of the subcritical boiler flue, and solves the problems of high exhaust temperature and increased exhaust heat loss in the prior art.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is as follows: the utility model provides a condensate water system heated by utilizing the waste heat of a subcritical boiler flue, including a cooling water tank, a connecting pipe is provided at the front end of the cooling water tank, the connecting pipe is connected to a heat exchanger, the heat exchanger is arranged in the boiler flue, a water inlet pipe is provided at the outlet of the heat exchanger, a water diversion pipe is provided at the top of the cooling water tank, the water diversion pipe is connected to a return pipe, the return pipe is connected to a circulating water tank, the circulating water tank is provided with a water outlet pipe, and a drain pipe is provided on one side of the cooling water tank to be connected to a deaerator.

[0006] Preferably, a direct connection pipe is provided at the front end of the cooling water tank.

[0007] Preferably, the heat exchanger is arranged at the tail end of the boiler flue.

[0008] Preferably, a circulation pump is provided on the water outlet pipe, and the water outlet pipe is connected back to the water return pipe.

[0009] Preferably, a water supply pipe is provided on the top of the cooling water tank.

[0010] Preferably, a condensation pump and a water inlet valve are provided on the water inlet pipe.

[0011] Preferably, the drain pipe is provided with a drain valve, a desalted water pump and a one-way valve.

[0012] Preferably, a second condensation pump and a direct connection valve are provided on the direct connection pipe.

[0013] Compared with the prior art, the advantages and positive effects of the utility model are:

[0014] 1. The utility model can utilize the waste heat of the subcritical boiler flue to heat the condensate, and can recycle the waste heat to increase the steam production of steelmaking and improve the power generation capacity. At the same time, after the exhaust temperature is reduced, the flue gas volume is reduced, and the power consumption of the induced draft fan is reduced;

[0015] 2. The utility model has the function of heating condensed water by utilizing the waste heat of the subcritical boiler flue, thus solving the problem of high exhaust temperature and increased exhaust heat loss in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0017] Figure 1 It is a structural schematic diagram of a condensate system heated by using the waste heat of the flue of a subcritical boiler;

[0018] In the above figure, 1. cooling water tank, 2. connecting pipe, 3. heat exchanger, 4. boiler flue, 5. water inlet pipe, 6. condensate pump, 7. water inlet valve, 8. direct pipe, 9. second condensate pump, 10. direct valve, 11. water diversion pipe, 12. return pipe, 13. circulating water tank, 14. water outlet pipe, 15. circulating pump, 16. water supply pipe, 17. drain pipe, 18. deaerator, 19. drain valve, 20. desalted water pump, 21. check valve. DETAILED DESCRIPTION

[0019] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0021] Embodiment 1, as Figure 1As shown, a condensate water system using waste heat from a subcritical boiler flue 4 for heating includes a cooling water tank 1 for storing condensate water. A connecting pipe 2 is provided at the front end of the cooling water tank 1. The connecting pipe 2 is connected to a heat exchanger 3. The heat exchanger 3 heats the condensate water flowing inside. The connecting pipe 2 sends the condensate water after heat exchange in the heat exchanger 3 to the cooling water tank 1. The heat exchanger 3 is provided in the boiler flue 4. The heat exchanger 3 uses waste heat from flue gas in the boiler flue 4 to heat the condensate water. An inlet pipe 5 is provided at the outlet of the heat exchanger 3, and the condensate water is introduced through the inlet pipe 5.

[0022] A water inlet pipe 11 is provided on the top of the cooling water tank 1. The water inlet pipe 11 is connected to the return pipe 12. The water inlet pipe 11 is used to replenish or lead out the circulating water in the return pipe 12. The return pipe 12 is connected to the circulating water tank 13. The circulating water tank 13 is used to store water for cooling the plant equipment. The circulating water tank 13 is provided with a water outlet pipe 14. The water in the circulating water tank 13 flows out through the water outlet pipe 14 to cool the equipment and then returns to the circulating water tank 13 through the return pipe 12. A drain pipe 17 is provided on one side of the cooling water tank 1 and is connected to the deaerator 18. The water in the cooling water tank 1 is sent to the deaerator 18 through the drain pipe 17. The deaerator 18 deoxygenates the sent water and sends it to other equipment for use.

[0023] The following is a detailed description of the design of the above key components:

[0024] A direct-connection pipe 8 is provided at the front end of the cooling water tank 1, and condensed water is directly delivered to the cooling water tank 1 through the direct-connection pipe 8 to avoid the water source not being able to be supplied in time when the water supply of the water inlet pipe 5 of the heat exchanger 3 is insufficient. The direct-connection pipe 8 is used as a backup supply when heat exchange is not required.

[0025] The heat exchanger 3 is arranged at the tail end of the boiler flue 4, and utilizes the waste heat of the flue gas to be discharged at the tail end of the boiler flue 4 to avoid affecting the overall temperature of the boiler flue 4 and affecting the environmental protection index.

[0026] The outlet pipe 14 is provided with a circulation pump 15, and the outlet pipe 14 is connected back to the return pipe 12. The circulation pump 15 sends the water in the circulating water tank 13 to the equipment that needs water cooling through the outlet pipe 14, and then flows back to the return pipe 12 to return to the circulating water tank 13, so as to realize the recycling of water.

[0027] A water supply pipe 16 is provided on the top of the cooling water tank 1, and water is additionally supplied to the cooling water tank 1 through the water supply pipe 16 to avoid affecting the water supply when the condensed water is insufficient.

[0028] The water inlet pipe 5 is provided with a condensate pump 6 and a water inlet valve 7. The condensate pump 6 is used to send condensate water into the heat exchanger 3 for heat exchange, and the water inlet valve 7 is used to control the flow rate of condensate water in the water inlet pipe 5 to maintain the heat exchange efficiency.

[0029] The drain pipe 17 is provided with a drain valve 19, a desalted water pump 20 and a one-way valve 21. The drain valve 19 is used to control the opening and closing of the drain pipe 17 to control drainage, the desalted water pump 20 is used to remove salt from the water, and the one-way valve 21 can prevent backflow of water.

[0030] The direct-connection pipe 8 is provided with a second condensate pump 9 and a direct-connection valve 10 . The second condensate pump 9 is used to deliver condensate directly into the cooling water tank 1 through the direct-connection pipe 8 . The direct-connection valve 10 is used to control the flow of condensate in the direct-connection pipe 8 .

[0031] The contents not described in detail in this specification belong to the prior art known to professionals in this field.

[0032] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A condensate system heated by waste heat from a subcritical boiler flue, characterized in that: It includes a cooling water tank, a connecting pipe is provided at the front end of the cooling water tank, the connecting pipe is connected to the heat exchanger, the heat exchanger is arranged in the boiler flue, a water inlet pipe is provided at the outlet of the heat exchanger, a water diversion pipe is provided on the top of the cooling water tank, the water diversion pipe is connected to the return pipe, the return pipe is connected to the circulating water tank, the circulating water tank is provided with a water outlet pipe, and a drain pipe is provided on one side of the cooling water tank to be connected to the deaerator.

2. The condensate water system using the waste heat of the subcritical boiler flue for heating according to claim 1 is characterized in that: A direct connection pipe is arranged at the front end of the cooling water tank.

3. The condensate water system using the waste heat of the subcritical boiler flue for heating according to claim 1 is characterized in that: The heat exchanger is arranged at the tail end of the boiler flue.

4. The condensate water system using waste heat from a subcritical boiler flue for heating according to claim 1, characterized in that: A circulation pump is arranged on the water outlet pipe, and the water outlet pipe is connected back to the water return pipe.

5. A condensate water system heated by using waste heat from a subcritical boiler flue according to claim 1 or 2, characterized in that: A water supply pipe is arranged on the top of the cooling water tank.

6. The condensate water system using waste heat from a subcritical boiler flue for heating according to claim 1, characterized in that: The water inlet pipe is provided with a condensation pump and a water inlet valve.

7. The condensate water system using waste heat from a subcritical boiler flue for heating according to claim 1, characterized in that: The drain pipe is provided with a drain valve, a desalted water pump and a one-way valve.

8. The condensate water system using waste heat from a subcritical boiler flue for heating according to claim 2, characterized in that: The direct connection pipe is provided with a second condensation pump and a direct connection valve.

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