Waste heat utilization system for air compressor of thermal power plant

Abstract

The utility model relates to a waste heat utilization system for an air compressor of a thermal power plant. The waste heat utilization system comprises the air compressor, a water tank, a circulating water pump, an air duct heat exchanger and a fan. The circulating water pump is arranged between a water inlet pipeline a of the air compressor and a water outlet pipeline A of the water tank, and water in the water tank can be supplied to a water circulation channel of the air compressor and then pumped back to the water tank through the water circulation channel of the air compressor. A water circulation passage of the air duct heat exchanger is connected between a water outlet pipeline a of the air compressor and a water inlet pipeline A of the water tank. The air inlet end of the draught fan is connected with the air circulation channel of the air channel heat exchanger, and external air can be led into the air channel heat exchanger to exchange heat with the water circulation channel. And the air outlet end of the fan is associated and matched with a hearth of the boiler through an air duct. According to the water-cooling and air-cooling double-heat-exchange system, heat generated by the air compressor can be recycled and sent to the boiler to be used, the air inlet temperature of the hearth is increased, coal consumption of the boiler can be reduced, and good environmental protection and economic benefits can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste heat recovery in thermal power plants, and in particular relates to a waste heat utilization system for air compressors in thermal power plants. Background Art

[0002] In the conventional cooling schemes for thermal power plant air compressors, commonly used cooling methods include water cooling and air cooling. In water-cooled air compressor systems, industrial water is often used directly as the cooling water source for the air compressor. In air-cooled air compressor systems, cooling air is led to the air compressor through the air duct and then discharged.

[0003] Using industrial water directly as the cooling water source for the air compressor has the prominent problem that the air compressor is prone to scaling and the heat cannot be effectively utilized. Even if the air compressor is cooled by cooling water and the heated cooling water is used as living and production water to achieve heat recovery, the premise is that these water and heat can be fully utilized. If the amount of hot water for living and production is relatively small, not only can the waste heat of the air compressor not be fully and effectively recovered, but it will also lead to a waste of water resources. In the operating system of the existing air-cooled air compressor, the cooling air is introduced to the air compressor through the air duct and then directly discharged to the external connection, and the heat obtained by the cold air from the air compressor cannot be utilized. Utility Model Content

[0004] In order to solve the problem that the waste heat generated by the air compressor cannot be effectively utilized, the utility model provides a thermal power plant air compressor waste heat utilization system, which is equipped with a water-cooled and air-cooled dual heat exchange system, which can recover the heat generated by the air compressor and send it to the boiler for utilization, and is used to increase the boiler's air inlet temperature, which helps to reduce the boiler's coal consumption.

[0005] The utility model solves the technical problem by adopting a technical solution: a thermal power plant air compressor waste heat utilization system, comprising an air compressor, a water tank, a circulating water pump, an air duct heat exchanger and a fan. The air compressor is provided with a water circulation passage for heat exchange.

[0006] The circulating water pump is arranged between the water inlet pipe a of the air compressor and the water outlet pipe A of the water tank, and can supply the water in the water tank to the water circulation passage of the air compressor, and then pump the water back to the water tank through the water circulation passage of the air compressor.

[0007] The water circulation passage of the air duct heat exchanger is connected between the water outlet pipe a of the air compressor and the water inlet pipe A of the water tank. The air inlet end of the fan is connected to the air circulation passage of the air duct heat exchanger, and can introduce external air into the air duct heat exchanger and the water circulation passage for heat exchange. The air outlet end of the fan is matched to the furnace of the boiler through the air duct association.

[0008] Optionally, a plurality of the air compressors are provided in parallel, a plurality of the circulating water pumps are provided in parallel, and a plurality of the air duct heat exchangers are provided in parallel.

[0009] The number of the air compressor, the circulating water pump and the air duct heat exchanger is the same.

[0010] Each of the air duct heat exchangers is matched with one of the fans.

[0011] Optionally, on the water inlet and outlet connecting pipelines of the air compressor, stop valves are respectively arranged at positions close to the water inlet of the air compressor and close to the water outlet of the air compressor.

[0012] Optionally, on the connecting pipelines on the water inlet and outlet sides of the circulating water pump, stop valves are respectively arranged at positions close to the water inlet end of the circulating water pump and close to the water outlet end of the circulating water pump.

[0013] Optionally, stop valves are provided on the water inlet and outlet pipes of the water circulation passage of the duct heat exchanger, respectively, at positions close to the water inlet and the water outlet of the duct heat exchanger.

[0014] Optionally, a check valve is provided on the water outlet pipe of the circulating water pump.

[0015] Optionally, a flow indicator is provided on the water outlet pipe close to the air compressor.

[0016] Optionally, a thermometer is provided on the water outlet pipe close to the water tank.

[0017] The beneficial effect of the utility model is that in the boiler system of a thermal power plant, the amount of air used for boiler combustion is extremely large, and there are enough cold sources. If the cold air of the boiler can be heated and the air inlet temperature of the boiler furnace is increased, the coal consumption of the boiler can be reduced. This patent involves a thermal power plant air compressor waste heat utilization system, which uses water and cold air as heat exchange media at the same time. The "waste heat" generated by the air compressor is recovered through the cold air medium and sent to the boiler assembly to increase the air inlet temperature of the furnace. The boiler system thus constructed can achieve the purpose of reducing the coal consumption of the boiler system while effectively recovering the waste heat of the air compressor, and has good environmental protection and economic benefits. When the water-cooling medium used is specifically selected as softened water, it can avoid the scaling problem of the air compressor caused by direct use of industrial water for cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of this patent.

[0019] Figure 2 This is a schematic diagram of the boiler system formed after connecting this patent to the boiler assembly.

[0020] In the figure: 100 boiler assembly, 101 first air duct, 102 second air duct, 103 flue, 104 first air preheater, 105 second air preheater, 106 furnace, 107 separator;

[0021] 10 air compressor, 11 water inlet pipeline a, 12 water outlet pipeline a; 20 water tank, 21 water inlet pipeline A, 22 water outlet pipeline A; 30 circulating water pump; 40 air duct heat exchanger; 50 fan;

[0022] 1. Stop valve; 2. Check valve; 3. Flow indicator; 4. Thermometer. DETAILED DESCRIPTION

[0023] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "front", "back", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0024] like Figure 1 to Figure 2 A thermal power plant air compressor waste heat utilization system shown in the figure includes an air compressor 10, a water tank 20, a circulating water pump 30, an air duct heat exchanger 40 and a fan 50. In the illustrated scheme, two of the air compressor 10, the circulating water pump 30 and the air duct heat exchanger 40 are provided in parallel, and one fan 50 is matched for each of the air duct heat exchangers 40.

[0025] The air compressor 10 is provided with a water circulation passage for heat exchange. The specific structure of the water circulation passage can be referred to the prior art, so it will not be described in detail.

[0026] The circulating water pump 30 is disposed between the water inlet pipe a11 of the air compressor 10 and the water outlet pipe A22 of the water tank 20, and can supply the water in the water tank 20 to the water circulation passage of the air compressor 10, and can pump the water from the water circulation passage of the air compressor 10 back to the water tank 20. The cooling water contained in the water tank 20 is selected to be softened water.

[0027] The water circulation passage on the air duct heat exchanger 40 is connected between the water outlet pipe a12 of the air compressor 10 and the water inlet pipe A21 of the water tank 20. The air inlet end of the fan 50 is connected to the air circulation passage on the air duct heat exchanger 40, and can introduce external air into the air duct heat exchanger 40 to achieve heat exchange with the water circulation passage of the air duct heat exchanger 40.

[0028] The air outlet end of the fan 50 is matched to the furnace 106 of the boiler through the air duct. In the figure, the first air duct 101 and the second air duct 102 are respectively configured at the exhaust ends of the two fans 50, and the other ends of the two air ducts are respectively connected to the first air preheater 104 and the second air preheater 105 of the boiler assembly 100, and after passing through the first air preheater 104 and the second air preheater 105, they are matched to the furnace 106 through pipes. The furnace 106 is matched with multiple separators 107 through pipelines. A flue 103 is provided in the space corresponding to the lower part of the air preheater and is associated with the separator 107.

[0029] The arrows in the figure show the process of heat exchange circulation of the cooling water drawn from the water tank 20 by the circulating water pump 30 .

[0030] To facilitate the isolation and maintenance of the system. On the water inlet and outlet connecting pipelines of the air compressor 10, stop valves 1 are respectively arranged near the water inlet and water outlet of the air compressor 10. At the same time, on the water inlet and water outlet connecting pipelines of the circulating water pump 30, stop valves 1 are respectively arranged near the water inlet and water outlet of the circulating water pump 30. And on the water inlet and water outlet pipes of the water circulation passage of the air duct heat exchanger 40, stop valves 1 are respectively arranged near the water inlet and water outlet of the air duct heat exchanger 40.

[0031] A check valve 2 is provided on the outlet pipe of the circulating water pump 30 to prevent water from flowing back. A flow indicator 3 is provided on the outlet pipe near the air compressor 10 to determine whether the cooling water is operating normally. A thermometer 4 is provided on the outlet pipe near the water tank 20 to monitor the temperature of the cooling water so that timely reminders can be made to intervene when abnormalities occur, so that the temperature of the cooling water can be maintained at a state that meets the cooling requirements of the air compressor.

[0032] Working process: The circulating water pump 30 sends the softened water in the water tank 20 into the air compressor 10 to take away the heat generated by the air compressor 10. The heated softened water is cooled by the air duct heat exchanger 40 and then returns to the water tank 20. The fan 50 obtains the heat of the softened water by sucking the cold air into the air duct heat exchanger 40, and finally sends the heated cold air into the furnace 106 of the boiler. The softened water after heat exchange cooling is used again in the cooling process of the air compressor 10 by the circulating water pump 30, and the heat generated by the air compressor 10 is continuously recovered and sent to the furnace 106 of the boiler in a reciprocating cycle.

[0033] Multiple air compressors 10, multiple circulating water pumps 30, and multiple air duct heat exchangers 40 are arranged in parallel, and as described above, stop valves 1 are respectively arranged at the water inlet and outlet ends / sides of the three. When a certain air compressor 10 and / or a certain circulating water pump 30 and / or a certain air duct heat exchanger 40 fails and needs to be repaired, it is not necessary to shut down the entire system, so that the purpose of troubleshooting can be achieved when the system is in normal operation. Since the model of the air duct heat exchanger 40 and the specific structure of its heat exchange channel can be selected from existing air duct heat exchangers to achieve appropriate matching, the specific structural form of the air duct heat exchanger 40 is not elaborated in detail in this patent.

[0034] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. The present invention can be improved in many aspects without violating the overall concept, and those familiar with the technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical concept disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A system for utilizing waste heat from an air compressor in a thermal power plant, comprising an air compressor, characterized in that: It also includes a water tank, a circulating water pump, an air duct heat exchanger and a fan; The circulating water pump is arranged between the water inlet pipe a of the air compressor and the water outlet pipe A of the water tank, and can supply the water in the water tank to the air compressor; The water circulation passage of the air duct heat exchanger is connected between the water outlet pipe a of the air compressor and the water inlet pipe A of the water tank; the air inlet end of the fan is connected to the air circulation passage of the air duct heat exchanger, and can introduce external air into the air duct heat exchanger to exchange heat with its water circulation passage; The air outlet of the fan is matched to the furnace of the boiler through an air duct.

2. A thermal power plant air compressor waste heat utilization system according to claim 1, characterized in that: The air compressors are provided in multiple numbers in parallel, the circulating water pumps are provided in multiple numbers in parallel, and the air duct heat exchangers are provided in multiple numbers in parallel; Each of the air duct heat exchangers is matched with one of the fans.

3. A thermal power plant air compressor waste heat utilization system according to claim 1 or 2, characterized in that: On the water inlet and outlet connecting pipelines of the air compressor, stop valves are respectively arranged at positions close to the water inlet and the water outlet of the air compressor.

4. A thermal power plant air compressor waste heat utilization system according to claim 3, characterized in that: On the connecting pipelines on the water inlet and water outlet sides of the circulating water pump, stop valves are respectively arranged at positions close to the water inlet end of the circulating water pump and close to the water outlet end of the circulating water pump.

5. A thermal power plant air compressor waste heat utilization system according to claim 4, characterized in that: On the water inlet and outlet pipes of the water circulation passage of the air duct heat exchanger, stop valves are respectively arranged at positions close to the water inlet and the water outlet of the air duct heat exchanger.

6. A thermal power plant air compressor waste heat utilization system according to claim 3, characterized in that: On the water inlet and outlet pipes of the water circulation passage of the air duct heat exchanger, stop valves are respectively arranged at positions close to the water inlet and the water outlet of the air duct heat exchanger.

7. A thermal power plant air compressor waste heat utilization system according to claim 1 or 2, characterized in that: On the connecting pipelines on the water inlet and water outlet sides of the circulating water pump, stop valves are respectively arranged at positions close to the water inlet end of the circulating water pump and close to the water outlet end of the circulating water pump.

8. A thermal power plant air compressor waste heat utilization system according to claim 1 or 2, characterized in that: On the water inlet and outlet pipes of the water circulation passage of the air duct heat exchanger, stop valves are respectively arranged at positions close to the water inlet and the water outlet of the air duct heat exchanger.

9. A thermal power plant air compressor waste heat utilization system according to claim 1 or 2, characterized in that: A check valve is provided on the water outlet pipe of the circulating water pump.

10. A thermal power plant air compressor waste heat utilization system according to claim 1 or 2, characterized in that: A flow indicator is arranged on the water outlet pipe close to the air compressor.

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