Air compressor compressed air heat recovery device

Abstract

The utility model discloses an air compressor compressed air heat recovery device, which comprises a thermal power generation circulation system and an air compressor heat exchange circulation system, the thermal power generation circulation system comprises a boiler, a steam turbine for driving a generator to generate electricity by utilizing the exhaust steam of the boiler, a condenser for condensing the exhaust steam of the steam turbine, and a cooling tower for heat exchange with the condenser, the condensate pump is used for pumping condensate water into the heat exchange circulating system of the air compressor; the deaerator is used for deaerating; the high-pressure heater is used for pressurizing and heating; the air compressor heat exchange circulating system comprises a heat exchanger, a primary water pump, a secondary water pump and an air compressor three-stage cooler, one end of the primary water pump is communicated with the heat exchanger, and the other end of the primary water pump is communicated with one end of the air compressor three-stage cooler; one end of a secondary water pump is communicated with a condensate pump, condensate is pumped into the heat exchanger, the heat exchanger is further communicated with a thermal power generation circulation system, and the condensate subjected to heat exchange is introduced into the thermal power generation circulation system.

Description

Technical Field

[0001] The utility model relates to an air compressor compressed air heat recovery device for a condensate water system and an air compressor system in a power plant. Background Art

[0002] In recent years, thermal power plants have carried out comprehensive energy services externally. In addition to conventional cogeneration and external supply of steam and hot water, some power plants have begun to install large centrifugal air compressors. By electrically driving the centrifugal air compressors, compressed air is supplied to users in surrounding industrial parks. The centrifugal air compressor is divided into three stages. After the air is compressed in each stage, the temperature rises sharply. To ensure the overall operation efficiency of the air compressor, the compressed air in each stage must be cooled before entering the next stage of compression. Therefore, the compressed air between the three stages of the air compressor needs to be cooled twice, and the last stage needs to be cooled once more. Thus, it is necessary to cool the centrifugal air compressor through a cooling system additionally. For large air compressors, the compression heat accounts for more than 85% of the operating power of the air compressor. Usually, the heat is exchanged to the atmosphere through cooling water, and this part of the heat is not utilized and is directly discharged into the environment along with the circulating water. Content of the Utility Model

[0003] The utility model provides an air compressor compressed air heat recovery device that directly exchanges heat between the heat of the three-stage air cooler after the air compressor and the condensate water system of the generator set.

[0004] The air compressor compressed air heat recovery device described in the utility model includes a thermal power generation cycle system and an air compressor heat exchange cycle system. The thermal power generation cycle system includes a boiler, a steam turbine that uses the boiler exhaust to drive the generator to generate electricity, a condenser for condensing the steam turbine exhaust, a cooling tower that exchanges heat with the condenser, a condensate water pump that pumps the condensate water into the air compressor heat exchange cycle system, a deaerator for deaeration, and a high-pressure heater for pressurization and heating. The air compressor heat exchange cycle system includes a heat exchanger, a primary water pump, a secondary water pump, and an air compressor three-stage cooler. One end of the primary water pump is connected to the heat exchanger, and the other end is connected to one end of the air compressor three-stage cooler; the other end of the air compressor three-stage cooler is connected to the heat exchanger. One end of the secondary water pump is connected to the condensate water pump, and the condensate water is pumped into the heat exchanger. The heat exchanger is also connected to the thermal power generation cycle system, and the condensate water after heat exchange is introduced into the thermal power generation cycle system.

[0005] Further, the condensate water pump is divided into two branches. The first branch passes through the low-pressure heater, and the second branch is connected to the secondary water pump. Part of the condensate water passes through the heat exchanger and then converges with the condensate water coming out of the low-pressure heater and flows into the deaerator.

[0006] The described air compressor compressed air heat recovery device, compared with the traditional air compressor cooling system, can save the additionally installed cooling circulating water system in the present utility model. The heat of the three-stage air cooler after the air compressor is directly exchanged with the condensate water of thermal power generation. Moreover, it can enable the condensate water in the thermal power generation cycle system to recover the compression heat generated by the air compressor into the thermal power generation cycle system, thereby increasing the condensate water temperature, reducing the extraction steam volume of the steam turbine for heating the condensate water, increasing the power generation output of the steam turbine generator set, ensuring that the compression heat is completely utilized, saving water and energy, improving the energy utilization efficiency, and having an obvious effect on the economic operation of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic structural diagram of an air compressor compressed air heat recovery device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0008] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0009] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" 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 directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0010] Such as Figure 1As shown in the figure, an air compressor compressed air heat recovery device includes a thermal power generation cycle system and an air compressor heat exchange cycle system. The thermal power generation cycle system includes a boiler 1, a steam turbine 3 that uses the exhaust steam of the boiler to drive a generator 2 to generate electricity, a condenser 4 for condensing the exhaust steam of the steam turbine, a cooling tower 5 that exchanges heat with the condenser, a condensate pump 6 that pumps the condensate into the air compressor heat exchange cycle system, a deaerator 7 for deaeration, and a high-pressure heater 8 for pressurizing and heating. The air compressor heat exchange cycle system includes a heat exchanger 9, a primary water pump 10, a secondary water pump 11, and an air compressor three-stage cooler 12. One end of the primary water pump is connected to the heat exchanger, and the other end is connected to one end of the air compressor three-stage cooler; the other end of the air compressor three-stage cooler is connected to the heat exchanger. One end of the secondary water pump is connected to the condensate pump, and the condensate is pumped into the heat exchanger. The heat exchanger is also connected to the thermal power generation cycle system, and the condensate water that has undergone heat exchange is passed into the thermal power generation cycle system. Compared with the traditional air compressor cooling system, the air compressor compressed air heat recovery device of the present invention can eliminate the need for an additional cooling circulating water system, directly exchange the heat of the three-stage air cooler after the air compressor with the condensate water of the thermal power generation, and can also enable the condensate water in the thermal power generation cycle system to recover the compression heat generated by the air compressor into the thermal power generation cycle system, thereby increasing the condensate water temperature, reducing the extraction steam volume of the steam turbine for heating the condensate water, increasing the power generation output of the steam turbine generator set, ensuring that the compression heat is completely utilized, saving water and energy, improving the energy use efficiency, and having an obvious effect on the economic operation of the power plant.

[0011] Further, specifically, the condensate water that has undergone heat exchange in the heat exchanger can be passed into the pipeline at any position between the deaerator and the condensate pump.

[0012] The heat exchanger is a plate heat exchanger.

[0013] Among them, a low-pressure heater 13 is also provided between the condensate pump and the deaerator, and a feed water pump 14 is also provided between the deaerator and the high-pressure heater. The sequential connection order of the thermal power generation cycle system includes: boiler, steam turbine, condenser, condensate pump, low-pressure heater, deaerator, feed water pump, high-pressure heater, boiler.

[0014] Among them, the steam turbine is also connected to the generator, the condenser is connected to the cooling tower, the condensate pump is divided into two branches. The first branch passes through the low-pressure heater, and the second branch is connected to the secondary water pump. Part of the condensate water passes through the heat exchanger and then converges with the condensate water coming out of the low-pressure heater and flows into the thermal power generation cycle system.

[0015] Specifically, for example, the condensate water of a power plant is led out before the low-pressure heater, and after heat exchange in a heat exchanger, it returns to before the high-pressure heater. The condensate water is heated to about 85°C by this device. A 3x650 Nm3 / min compressed air device built in a certain power plant recovers 9,600,000 kcal / h of waste heat, which can save 1,491 kg / h of standard coal, and 10,437 t / a of standard coal annually (boiler efficiency method), and 10,570 t / a of standard coal annually (unit heat consumption method).

[0016] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An air compressor compressed air heat recovery device, characterized in that: The invention comprises a thermal power generation circulation system and an air compressor heat exchange circulation system. The thermal power generation circulation system comprises a boiler (1), a steam turbine (3) which uses boiler exhaust steam to drive a generator (2) to generate electricity, a condenser (4) for condensing the steam turbine exhaust, a cooling tower (5) for heat exchange with the condenser, a condensing water pump (6) for pumping condensed water into the air compressor heat exchange circulation system, a deaerator (7) for deoxygenation, and a high-pressure heater (8) for pressurized heating. The air compressor heat exchange circulation system comprises a heat exchanger (9), a primary water pump (10), a secondary water pump (11), and an air compressor tertiary cooler (12). One end of the primary water pump is connected to the heat exchanger, and the other end is connected to one end of the air compressor tertiary cooler; the other end of the air compressor tertiary cooler is connected to the heat exchanger. One end of the secondary water pump is connected to the condensing water pump to pump condensed water into the heat exchanger. The heat exchanger is also connected to the thermal power generation circulation system to pass the condensed water after heat exchange into the thermal power generation circulation system.

2. The compressed air heat recovery device for air compressor according to claim 1, characterized in that: The condensate pump is divided into two branches. The first branch passes through the low-pressure heater (13), and the second branch is connected to the secondary water pump. Part of the condensate passes through the heat exchanger and then merges with the condensate from the low-pressure heater to flow into the thermal power generation circulation system.

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