Waste heat power generation system of centrifugal air compressor

Abstract

The utility model relates to the technical field of waste heat utilization of centrifugal air compressors, in particular to a tar residue treatment system. The centrifugal air compressor is provided with N stages of compressors, N is larger than or equal to 2, and the N stages of compressors are connected with the N-1 efficient heat exchangers in series through pipelines. An outlet of the high-efficiency heat exchanger is connected with an inlet pipeline of the organic working medium-hot water heat exchanger, an outlet of the organic working medium-hot water heat exchanger is connected with an inlet pipeline of the high-efficiency heat exchanger to form a circulating water system, and the water replenishing pipeline is connected with the circulating water system; an outlet of the organic working medium-hot water heat exchanger is connected with an inlet pipeline of a working medium expansion machine, an outlet of the working medium expansion machine is connected with an inlet pipeline of a working medium condenser, and an outlet of the working medium condenser is connected with an inlet pipeline of the organic working medium-hot water heat exchanger to form an organic working medium circulating system; the working medium expander is connected with a generator pipeline. The waste heat of the centrifugal air compressor can be effectively utilized, and the current situation of insufficient power supply of a factory can be relieved.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization technology of centrifugal air compressors, specifically a waste heat power generation system for centrifugal air compressors. Background Technology

[0002] Centrifugal air compressors are mechanical devices that use high-speed rotating impellers to compress gas. They are widely used in industrial manufacturing, energy, chemical and other fields. Centrifugal air compressors are the "power heart" of coking plants. Through the high-speed rotation of the impeller, they "pump" compressed air to provide the "lifeblood" for coke oven systems, dust removal equipment and pneumatic valves, driving the efficient operation of the entire plant.

[0003] However, centrifugal air compressors generate a large amount of compression heat during operation. Centrifugal air compressors used in coking production are usually equipped with three-stage compressors, so a large amount of circulating water is required to be divided into three paths to cool the compressor. At present, most of the heat carried away by this circulating water is released through cooling towers or through evaporative cooling systems to release this part of the heat into the atmosphere.

[0004] Whether it's a cooling tower or an evaporative cooling system, the heat energy released by the cooler is wasted, and the heat is not fully recovered. In addition, many factories currently face the problem of high power consumption from their production equipment. The number of high-power, high-load devices is increasing, and sudden power outages caused by unstable power loads and current overloads can have immeasurable consequences for the factory. Utility Model Content

[0005] To overcome the shortcomings of the existing technology, this utility model provides a centrifugal air compressor waste heat power generation system, which can effectively utilize the waste heat of the centrifugal air compressor and alleviate the current situation of insufficient power supply in the plant area.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A centrifugal air compressor waste heat power generation system includes a centrifugal air compressor with N stages of compressors, where N≥2. The N stages of compressors are connected in series with N-1 high-efficiency heat exchangers via pipelines. The outlet of each high-efficiency heat exchanger is connected to the inlet pipeline of an organic working fluid-hot water heat exchanger, forming a circulating water system. A makeup water pipeline is connected to the circulating water system. The outlet of each organic working fluid-hot water heat exchanger is connected to the inlet pipeline of a working fluid expander, which is connected to the inlet pipeline of a working fluid condenser. The outlet of each working fluid condenser is connected to the inlet pipeline of the organic working fluid-hot water heat exchanger, forming an organic working fluid circulation system. The working fluid expander is connected to a generator via pipelines.

[0008] Furthermore, the N-stage compressor is a three-stage compressor, consisting of a first-stage compressor, a second-stage compressor, and a third-stage compressor. The N-1 high-efficiency heat exchangers are two high-efficiency heat exchangers, consisting of a first high-efficiency heat exchanger and a second high-efficiency heat exchanger. The first-stage compressor, the first high-efficiency heat exchanger, the second-stage compressor, the second high-efficiency heat exchanger, and the third-stage compressor are connected in sequence by pipelines. The outlet of the third-stage compressor is connected to the waste heat regeneration dryer by pipelines.

[0009] Furthermore, a working fluid pump is installed on the pipeline connecting the outlet of the working fluid condenser to the inlet of the organic working fluid-hot water heat exchanger.

[0010] Furthermore, a water supply pump is installed on the water supply pipeline.

[0011] Furthermore, a circulating pump and a pressure stabilizing tank are installed on the pipeline connecting the outlet of the organic working fluid-hot water heat exchanger and the inlet of the high-efficiency heat exchanger.

[0012] Furthermore, the generator is connected to the power grid via a grid-connected cabinet to complete the electrical connection and grid-connection control.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. In this utility model, an N-stage compressor and N-1 high-efficiency heat exchangers are connected in series via pipelines. The outlet of the high-efficiency heat exchanger is connected to the inlet pipeline of the organic working fluid-hot water heat exchanger, and the outlet of the organic working fluid-hot water heat exchanger is connected to the inlet pipeline of the high-efficiency heat exchanger, forming a circulating water system. The makeup water pipeline is connected to the circulating water system. The outlet of the organic working fluid-hot water heat exchanger is connected to the inlet pipeline of the working fluid expander, the outlet of the working fluid expander is connected to the inlet pipeline of the working fluid condenser, and the outlet of the working fluid condenser is connected to the inlet pipeline of the organic working fluid-hot water heat exchanger, forming an organic working fluid circulation system.

[0015] This invention recovers the low-grade heat energy from an N-stage compressor through N-1 stage high-efficiency heat exchangers and transfers it to circulating water. The water then passes through an organic working fluid-hot water heat exchanger before being transferred to the organic working fluid to generate electricity. This reduces investment in factory buildings and equipment, alleviates the current power shortage in the factory area, reduces the use of circulating cooling water, and allows for year-round operation. It converts the heat energy of the air into electrical energy, achieving comprehensive energy utilization in a cascade manner.

[0016] 2. This invention achieves the recycling of industrial water and organic media through a circulating water system and an organic working fluid recycling system. The liquid working fluid undergoes two-stage filtration before flowing into the working fluid pump. After being pressurized by the pump, the low-temperature working fluid is then sent back to the working fluid-hot water heat exchanger for heating. This completes the entire cycle of air compressor waste heat recovery + organic working fluid recycling for power generation. This organic working fluid recycling process is pollution-free and allows for stable recycling. By recycling industrial water and organic media, enterprises can achieve a win-win situation in terms of economic and environmental benefits, and can also promote the industry's transformation towards low-carbon and sustainable development, providing important support for global resource protection and climate change response.

[0017] 3. This utility model is a three-stage compressor, consisting of a first-stage compressor, a second-stage compressor, and a third-stage compressor. It also includes two high-efficiency heat exchangers, namely a first-stage high-efficiency heat exchanger and a second-stage high-efficiency heat exchanger. The first-stage compressor, the first high-efficiency heat exchanger, the second-stage compressor, the second high-efficiency heat exchanger, and the third-stage compressor are connected sequentially by pipelines. After the air source enters the centrifugal air compressor, it undergoes three stages of compression and two stages of heat exchange, maintaining an outlet temperature of approximately 120℃. The circulating water undergoes two stages of heat exchange to ensure that the temperature entering the waste heat regeneration dryer in the next stage is between 110 and 130℃. This utility model ensures the normal operation of the waste heat regeneration dryer through three stages of compression and two stages of heat exchange, maintaining a heat recovery rate of approximately 55%, and a hot water outlet temperature of approximately 80 to 90℃.

[0018] 4. This utility model includes a water supply pump on the water supply pipeline and a circulation pump and a pressure stabilizing tank on the circulating water system. The water supply pump replenishes lost water, maintains pressure balance, and prevents equipment damage. The circulation pump provides power, and the pressure stabilizing tank absorbs shocks and stabilizes pressure. Together, they can improve the reliability, energy efficiency ratio, and equipment lifespan of the circulating water system, making them indispensable, especially in situations with frequent load fluctuations.

[0019] 5. After generating electricity, the generator of this utility model synchronizes the voltage, frequency, and phase through the grid connection cabinet. After confirming the matching, the circuit breaker is closed to transmit the electrical energy to the plant's power grid. This reduces heat loss and alleviates the pressure on the plant's electrical load. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure and process principle of this utility model.

[0021] The diagram shows the following components: 1. Centrifugal air compressor; 2. Primary compressor; 3. Secondary compressor; 4. Tertiary compressor; 51. First high-efficiency heat exchanger; 52. Second high-efficiency heat exchanger; 6. Circulating water pump; 7. Pressure stabilizing tank; 8. Make-up water pump; 9. Organic working fluid-hot water heat exchanger; 10. Working fluid expander; 11. Generator; 12. Grid connection cabinet; 13. Working fluid condenser; 14. Working fluid pump. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] In the description of this utility model, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0027] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0028] like Figure 1 As shown, a centrifugal air compressor waste heat power generation system includes a centrifugal air compressor 1, a primary compressor 2, a secondary compressor 3, a tertiary compressor 4, a first high-efficiency heat exchanger 51, a second high-efficiency heat exchanger 52, a circulating water pump 6, a pressure stabilizing tank 7, a makeup water pump 8, an organic working fluid-hot water heat exchanger 9, a working fluid expander 10, a generator 11, a grid connection cabinet 12, a working fluid condenser 13, and a working fluid pump 14. The centrifugal air compressor 1, primary compressor 2, secondary compressor 3, tertiary compressor 4, first high-efficiency heat exchanger 51, second high-efficiency heat exchanger 52, circulating water pump 6, pressure stabilizing tank 7, makeup water pump 8, and organic working fluid-hot water heat exchanger 9 constitute an air compressor waste heat recovery system, while the working fluid expander 10, generator 11, grid connection cabinet 12, working fluid condenser 13, and working fluid pump 14 constitute an organic working fluid power generation system.

[0029] In this embodiment, the centrifugal air compressor 1 is equipped with a primary compressor 2, a secondary compressor 3 and a tertiary compressor 4. The outlet of the primary compressor 2 is connected to the inlet pipe of the first high-efficiency heat exchanger 51. The outlet of the first high-efficiency heat exchanger 51 is connected to the inlet pipe of the secondary compressor 3. The outlet of the secondary compressor 3 is connected to the inlet pipe of the second high-efficiency heat exchanger 52. The outlet of the second high-efficiency heat exchanger 52 is connected to the inlet pipe of the tertiary compressor 4. The outlet of the tertiary compressor 4 is connected to the pipe of the primary waste heat regeneration dryer.

[0030] The outlets of the first high-efficiency heat exchanger 51 and the second high-efficiency heat exchanger 52 are connected to the inlet pipes of the organic working fluid-hot water heat exchanger 9, and the outlet of the organic working fluid-hot water heat exchanger 9 is connected to the inlet pipes of the first high-efficiency heat exchanger 51 and the second high-efficiency heat exchanger 52, forming a circulating water system. Two circulating water pumps 6 are connected in parallel on the pipes connecting the outlet of the organic working fluid-hot water heat exchanger 9 to the inlet of the first high-efficiency heat exchanger 51 and the second high-efficiency heat exchanger 52, and a pressure stabilizing tank 7 is provided. The circulating water pumps 6 provide power, and the pressure stabilizing tank 7 absorbs shocks and stabilizes the pressure. Together, they improve the reliability, energy efficiency ratio, and equipment lifespan of the circulating water system.

[0031] The outlet of the organic working fluid-hot water heat exchanger 9 is connected to the inlet of the first high-efficiency heat exchanger 51 and the second high-efficiency heat exchanger 52 via a pipe that is also connected to a water supply pipeline. Two water supply pumps 8 are connected in parallel on the water supply pipeline. The water supply pumps 8 replenish the water lost from the circulating water system, maintain system pressure balance, and prevent damage to system equipment.

[0032] The outlet of the organic working fluid-hot water heat exchanger 9 is connected to the inlet pipe of the working fluid expander 10. The outlet of the working fluid expander 10 is connected to the inlet pipe of the working fluid condenser 13. The outlet of the working fluid condenser 13 is connected to the inlet pipe of the organic working fluid-hot water heat exchanger 9, forming an organic working fluid circulation system. A working fluid pump 14 is installed on the pipe connecting the outlet of the working fluid condenser 13 and the inlet of the organic working fluid-hot water heat exchanger 9.

[0033] The outlet of the working fluid expander 10 is connected to the generator 11 via a pipeline. The generator 11 is connected to the power grid through the grid connection cabinet 12, completing the electrical connection and grid connection control. After generating electricity, the generator 11 synchronizes the voltage, frequency, and phase through the grid connection cabinet 12. After confirming the matching, the circuit breaker is closed to transmit the electrical energy to the plant's power grid. This reduces heat loss and alleviates the pressure on the plant's power load.

[0034] The working principle and process of this utility model are as follows:

[0035] 1. Air at 25℃ enters the first-stage compressor 2 of centrifugal air compressor 1. After compression by the first-stage compressor 2, the temperature rises. The high-temperature compressed air and circulating water undergo sufficient heat exchange in the first-stage high-efficiency heat exchanger 51. The compressed air after heat exchange then enters the second-stage compressor 3. After compression by the second-stage compressor 3, the temperature rises again. The high-temperature compressed air and circulating water undergo sufficient heat exchange in the second-stage high-efficiency heat exchanger 52. The compressed air after heat exchange then enters the third-stage compressor 4. After compression by the third-stage compressor 4, the temperature of the compressed air rises to about 120℃ and enters the first-stage waste heat regeneration dryer.

[0036] After the air source enters the centrifugal air compressor 1, it undergoes 3 stages of compression and 2 stages of heat exchange, and the outlet temperature is maintained at around 120℃. The purpose of circulating water undergoing two stages of heat exchange is to ensure that the temperature of the compressed air entering the subsequent waste heat regeneration dryer is between 110 and 130℃, thereby meeting the usage requirements of the waste heat regeneration dryer. At this time, the heat recovery rate is maintained at approximately 55%, and the hot water outlet temperature is around 80 to 90℃.

[0037] 2. After sufficient heat exchange, the 80-90°C hot water flows into the organic working fluid-hot water heat exchanger 9, which further transfers heat energy to the organic working fluid. The cooled 55-65°C hot water flows back to the high-efficiency heat exchanger for reuse. Industrial water at approximately 25°C is periodically replenished to the circulating water system through the makeup water pipeline.

[0038] 3. When the organic working fluid is heated, its temperature rises and it is transformed into a high-temperature, high-pressure gas or a supercritical fluid. Then it enters the working fluid expander 10 to expand and do work. During this process, the internal energy and pressure energy of the organic working fluid are converted into mechanical energy, which drives the rotor of the working fluid expander to rotate, and then drives the rotor of the generator to rotate to generate electricity through the coupling.

[0039] 4. After performing work, the low-temperature, low-pressure organic working fluid enters the working fluid condenser 13 for cooling and liquefaction. Finally, it is pressurized by the working fluid pump 14 and returned to the organic working fluid-hot water heat exchanger 9 for reuse. The liquid working fluid flows into the working fluid pump 14 after two stages of filtration. After being pressurized by the working fluid pump 14, the low-temperature working fluid is sent back to the organic working fluid-hot water heat exchanger 9 for heating. This completes the entire cycle of air compressor waste heat recovery + organic working fluid recycling power generation.

[0040] 5. After generator 11 generates electricity, voltage, frequency, and phase synchronization are achieved through grid connection cabinet 12. After confirming matching, the circuit breaker is closed to transmit electrical energy to the plant's power grid. This invention reduces heat loss and alleviates the pressure on the plant's electrical load.

[0041] This invention involves installing two external high-efficiency heat exchangers and modifying the primary, secondary, and tertiary compressor chambers of a centrifugal air compressor. The heat energy of the high-temperature compressed air in the compressor chamber is extracted using circulating water, which significantly reduces the air compressor station's consumption of circulating water and the use of circulating water pumps in the cooling tower. If a dedicated evaporative cooling system is installed on-site, the required floor space will be greatly reduced.

[0042] After being heated and expanding, the organic working fluid exits the working fluid expander 10 and enters the working fluid condenser 13 to cool and condense into a liquid. The liquid working fluid undergoes two stages of filtration before flowing into the working fluid pump 14. After being pressurized by the pump, the low-temperature working fluid is returned to the organic working fluid-hot water heat exchanger 9 for reheating. This completes the entire cycle of air compressor waste heat recovery + organic working fluid recycling for power generation. This organic working fluid recycling process is pollution-free and allows for stable recycling.

[0043] This invention utilizes waste heat extraction from centrifugal air compressors for organic working fluid power generation. Unlike traditional energy transfer methods, this technology introduces a novel concept of converting heat energy into electrical energy. The heat released by the air compressor is fully collected and extracted, then exchanged with an organic working fluid to generate electricity for grid connection. This reduces heat loss and alleviates the pressure on the plant's electrical load.

[0044] This invention can be used year-round, breaking the seasonal dependence of some waste heat recovery and energy-saving processes. For example, air compressor waste heat refrigeration can only be used in summer, and air compressor waste heat heating can only be used in winter, which is entirely dependent on the needs of local climate factors.

[0045] This invention can reduce investment in factory buildings and equipment, alleviate the current situation of insufficient power supply in the factory area, reduce the use of circulating cooling water, and the process can be used all year round. It converts the heat energy of the air into electrical energy and realizes the comprehensive utilization of energy in a cascade manner.

[0046] The above description is only a part of the specific embodiments of this utility model. The protection scope of this utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and utility model concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A centrifugal air compressor waste heat power generation system, characterized in that: This includes a centrifugal air compressor, which has an N-stage compressor, where N ≥ 2, and the N-stage compressor is connected in series with N-1 high-efficiency heat exchangers via pipelines. The outlet of the high-efficiency heat exchanger is connected to the inlet pipe of the organic working medium-hot water heat exchanger, and the outlet of the organic working medium-hot water heat exchanger is connected to the inlet pipe of the high-efficiency heat exchanger to form a circulating water system. The water supply pipe is connected to the circulating water system. The outlet of the organic working fluid-hot water heat exchanger is connected to the inlet pipe of the working fluid expander, the outlet of the working fluid expander is connected to the inlet pipe of the working fluid condenser, and the outlet of the working fluid condenser is connected to the inlet pipe of the organic working fluid-hot water heat exchanger, forming an organic working fluid circulation system. The working fluid expander is connected to the generator via pipeline.

2. The centrifugal air compressor waste heat power generation system according to claim 1, characterized in that: The N-stage compressor is a three-stage compressor, consisting of a first-stage compressor, a second-stage compressor, and a third-stage compressor. The N-1 high-efficiency heat exchangers are two high-efficiency heat exchangers, consisting of a first high-efficiency heat exchanger and a second high-efficiency heat exchanger. The first-stage compressor, the first high-efficiency heat exchanger, the second-stage compressor, the second high-efficiency heat exchanger, and the third-stage compressor are connected in sequence by pipelines. The outlet of the third-stage compressor is connected to the waste heat regeneration dryer by pipelines.

3. The centrifugal air compressor waste heat power generation system according to claim 1, characterized in that: A working fluid pump is installed on the pipeline connecting the outlet of the working fluid condenser to the inlet of the organic working fluid-hot water heat exchanger.

4. A centrifugal air compressor waste heat power generation system according to claim 1, characterized in that: A water supply pump is installed on the water supply pipeline.

5. A centrifugal air compressor waste heat power generation system according to claim 1, characterized in that: A circulation pump and a pressure stabilizing tank are installed on the pipeline connecting the outlet of the organic working fluid-hot water heat exchanger and the inlet of the high-efficiency heat exchanger.

6. A centrifugal air compressor waste heat power generation system according to claim 1, characterized in that: The generator is connected to the power grid via a grid-connected cabinet to complete electrical connection and grid-connection control.

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