Compressed air energy storage system for coupling absorption type heat pump combined cooling heating and power supply

Abstract

The utility model relates to a coupling absorption heat pump combined cooling heating and power compressed air energy storage system, which comprises an air storage tank, a plurality of stages of air compression units, a plurality of stages of air expansion units, a heat exchange unit and a waste heat utilization unit, the first medium input ends of the multiple stages of air compression units are all connected with the output end of the normal-temperature water tank, the first medium output ends of the multiple stages of air compression units are all connected with the input end of the high-temperature water tank, and the second medium input ends of the multiple stages of air expansion units are all connected with the output end of the high-temperature water tank. The waste heat utilization unit comprises a medium-temperature water tank and an absorption heat pump, the second medium output ends of the multiple stages of air expansion units are all connected with the input end of the medium-temperature water tank, and the output end of the medium-temperature water tank is connected with the input end of the absorption heat pump. The compressed air energy storage system solves the problem that an existing compressed air energy storage system is low in comprehensive energy efficiency.

Description

Technical Field

[0001] The utility model relates to the field of energy storage and comprehensive energy utilization, and particularly refers to a compressed air energy storage system coupled with an absorption heat pump for combined cooling, heating and power supply. Background Art

[0002] Energy storage is an important way of energy consumption. Currently, the main energy storage methods include electrochemical energy storage, gravity energy storage, compressed air energy storage, flywheel energy storage, supercapacitor energy storage, etc. Among many energy storage methods, compressed air energy storage has attracted more and more attention due to its environmental protection and safety characteristics.

[0003] It can be seen from the disclosed background art that the existing compressed air energy storage mainly has the disadvantage of relatively low comprehensive energy efficiency in the technical solution: First, in the compressed air energy storage technology using water heat storage, due to the inherent characteristics of water itself, the temperature is not suitable to be too high, resulting in low heat storage grade, low temperature at the inlet of the turbine for compressed air, and low expansion power generation efficiency; Second, after expansion power generation, not all of the medium-temperature water for heat exchange is utilized. The existing treatment method is to cool the medium-temperature water and then return it to the low-temperature water storage tank for use in the cooling of the next air compression process, resulting in relatively low comprehensive energy efficiency. Summary of the Utility Model

[0004] Aiming at the deficiencies of the existing technology, the utility model provides a compressed air energy storage system coupled with an absorption heat pump for combined cooling, heating and power supply. This system does not consume fossil fuels and has no environmental pollution. By optimizing the system design, it makes full use of waste heat and solves the problem of low comprehensive energy efficiency of the existing compressed air energy storage.

[0005] The utility model is realized through the following technical solutions. A compressed air energy storage system coupled with an absorption heat pump for combined cooling, heating and power supply includes an air storage tank, several stages of air compression units connected to the input end of the air storage tank, and several stages of air expansion units connected to the output end of the air storage tank. It also includes a heat exchange unit and a waste heat utilization unit. The heat exchange unit includes a normal temperature water tank and a high temperature water tank. The first medium input ends of several stages of air compression units are all connected to the output end of the normal temperature water tank, and the first medium output ends of several stages of air compression units are all connected to the input end of the high temperature water tank. The second medium input ends of several stages of air expansion units are all connected to the output end of the high temperature water tank. The waste heat utilization unit includes a medium temperature water tank and an absorption heat pump. The second medium output ends of several stages of air expansion units are all connected to the input end of the medium temperature water tank, and the output end of the medium temperature water tank is connected to the input end of the absorption heat pump.

[0006] During energy storage in this solution, the heat generated when the normal temperature water tank conveys normal temperature water and the air compression system compresses air is used for heat exchange to cool the high-temperature compressed air, enabling the normal temperature compressed air to enter the air storage tank for storage. Meanwhile, the high-temperature water after heat exchange enters the high-temperature water tank for storage. During power generation, the high-temperature water in the high-temperature water tank is used to heat the normal temperature air entering the air expansion system, heating the compressed air, and enabling the heated compressed air to enter the air turbine for full expansion, thereby driving the generator to generate electricity and improving the expansion power generation efficiency. At the same time, the medium-temperature water after heat exchange enters the medium-temperature water tank for storage, and the waste heat of the medium-temperature water can be further utilized through an absorption heat pump to output cold and hot water externally, supplying heat load in winter and cold load in summer, reducing the cold source loss of the system, and further improving the comprehensive energy utilization efficiency.

[0007] As an optimization, the number of stages of the several-stage air compression unit is 4 to 8 stages.

[0008] As an optimization, the air compression unit includes an air compressor and an inter-stage cooler connected in sequence along the compressed air conveying direction, and the inter-stage cooler is provided with a first medium input end and a first medium output end.

[0009] As an optimization, the number of stages of the several-stage air expansion unit is 2 to 4 stages.

[0010] As an optimization, the air expansion unit includes an inter-stage heater and an air turbine connected in sequence along the compressed air conveying direction, and the inter-stage heater is provided with a second medium input end and a second medium output end.

[0011] As an optimization, the high-temperature water tank is a pressure-bearing water storage floating roof tank.

[0012] The beneficial effects of the present utility model are as follows: 1) This system adopts multi-stage air compression and inter-stage cooling to realize the preparation of compressed air and recover the heat in the compression process, improving the thermal utilization efficiency of the air compression process; 2) When the air expands, the heat recovered and stored is fed back to the compressed air to increase its temperature, thereby improving the power generation efficiency; 3) The medium-temperature hot water after heat exchange is further utilized through an absorption heat pump to supply heat and cold externally, reducing the cold source loss of the system and improving the comprehensive energy utilization efficiency; 4) This system realizes the coupling of the air compression unit and the air expansion unit through the heat exchange unit and the waste heat utilization unit, thereby making full use of the heat waste of the entire system, without consuming fossil fuels and without environmental pollution, and solving the problem of low comprehensive energy efficiency of the existing compressed air energy storage system. Description of the Drawings

[0013] Figure 1 It is a schematic flow chart of the present utility model;

[0014] As shown in the figure:

[0015] 1. Air compressor, 2. Inter-stage cooler, 3. Normal temperature water tank, 4. Air storage tank, 5. High temperature water tank, 6. Inter-stage heater, 7. Air turbine, 8. Medium temperature water tank, 9. Absorption heat pump. Specific embodiments

[0016] To clearly illustrate the technical features of this solution, the following will elaborate on this solution through specific embodiments.

[0017] As Figure 1 shown, a compressed air energy storage system coupled with an absorption heat pump for combined cooling, heat and power supply includes an air storage tank 4, several stages of air compression units connected to the input end of the air storage tank, and several stages of air expansion units connected to the output end of the air storage tank. It also includes a heat exchange unit and a waste heat utilization unit. The heat exchange unit includes a normal temperature water tank 3 and a high temperature water tank 5. The first medium input ends of the several stages of air compression units are all connected to the output end of the normal temperature water tank 3, and the first medium output ends of the several stages of air compression units are all connected to the input end of the high temperature water tank 5. The second medium input ends of the several stages of air expansion units are all connected to the output end of the high temperature water tank 5. In this embodiment, the high temperature water tank is a pressure-bearing water storage floating roof tank, with lower cost.

[0018] Specifically, the several stages of air compression units are connected in series with the input end of the air storage tank 4 through pipelines. The number of stages of the several stages of air compression units is 4 to 8. The compressed air energy storage system in this embodiment is provided with 4 stages of air compression units. The air compression unit includes an air compressor 1 and an inter-stage cooler 2 connected in sequence along the compressed air conveying direction. The inter-stage cooler 2 is provided with a first medium input end and a first medium output end, and the end inter-stage cooler is connected to the input end of the air storage tank. In this embodiment, the air compressor is connected with a motor, and the air compressor is driven by the motor to compress air. The first medium input ends of the 4-stage inter-stage coolers 2 and the output end of the normal temperature water tank 3 are connected in parallel through pipelines, and the first medium output ends of the 4-stage inter-stage coolers 2 and the input end of the high temperature water tank 5 are connected in parallel through pipelines. To facilitate the normal temperature water tank 3 to transport normal temperature water to each stage of the inter-stage cooler 2, a delivery pump is provided at the output end of the normal temperature water tank 3, and a regulating valve is installed at the first medium input end of each stage of the inter-stage cooler 2.

[0019] The waste heat utilization unit includes a medium temperature water tank 8 and an absorption heat pump 9. The second medium output ends of the several stages of air expansion units are all connected to the input end of the medium temperature water tank 8, and the output end of the medium temperature water tank 8 is connected to the input end of the absorption heat pump 9. In this embodiment, the absorption heat pump 9 is a lithium bromide absorption heat pump.

[0020] Specifically, the several - stage air expansion units are connected in series with the output end of the air storage tank 4 through pipelines. The number of stages of the several - stage air expansion units is 2 to 4 stages. The compressed - air energy - storage system of this embodiment is provided with 2 - stage air compression units. The air expansion unit includes an inter - stage heater 6 and an air turbine 7 connected in sequence along the compressed - air conveying direction. The inter - stage heater 6 is provided with a second - medium input end and a second - medium output end. The inter - stage heater at the first end is connected to the output end of the air storage tank. In this embodiment, the air turbine 7 is connected to a generator, and the generator is driven to generate electricity by the air turbine. The second - medium input ends of the two - stage inter - stage heaters 6 are connected in parallel with the output end of the high - temperature water tank 5 through pipelines, and the second - medium output ends of the two - stage inter - stage heaters 6 are connected in parallel with the input end of the medium - temperature water tank 8 through pipelines. To facilitate the high - temperature water tank 5 to deliver high - temperature water to each inter - stage heater 6, a delivery pump is provided at the output end of the high - temperature water tank 5, and a regulating valve is installed at the second - medium input end of each inter - stage heater 6. To facilitate the medium - temperature water tank 8 to deliver medium - temperature water to the absorption heat pump 9, a delivery pump is provided at the output end of the medium - temperature water tank 8. To facilitate the control of the air intake and air output of the air storage tank 4, regulating valves are installed at both the input end and the output end of the air storage tank 4.

[0021] Working principle: During energy storage, the outside air is multi - stage compressed by a 4 - stage air compression unit. During the compression process, the outside air enters the air compressor 1 for compression to generate high - temperature compressed air. After the high - temperature compressed air is led out, it enters the inter - stage cooler 2. The high - temperature compressed air is cooled to 30°C after heat exchange with the normal - temperature water delivered by the normal - temperature water tank 3. The cooled normal - temperature compressed air enters the next - stage air compression unit for further compression and heat exchange. Finally, the normal - temperature compressed air delivered by the inter - stage cooler 2 at the end is stored in the air storage tank 4. At the same time, the normal - temperature water that has undergone heat exchange in this process is heated to 180°C and sent to the high - temperature water tank 5 for storage.

[0022] During power generation, the normal - temperature compressed air in the air storage tank 4 is multi - stage heated and expanded by a 2 - stage air expansion unit. During the expansion process, the normal - temperature compressed air first enters the inter - stage heater 6. The normal - temperature compressed air is heated by heat exchange with the high - temperature water delivered by the high - temperature water tank 6. After heating, it enters the air turbine 7 to expand and do work, so that the air turbine drives the generator to generate electricity. The exhausted air enters the next - stage air expansion unit for further heating and expansion power generation. Finally, the air turbine 7 at the end discharges the end air into the outside atmosphere. At the same time, the high - temperature water that has undergone heat exchange in this process is cooled to 90°C and sent to the medium - temperature water tank 8 for storage. The medium - temperature water in the medium - temperature water tank 8 is used as a heat source to supply the absorption heat pump 9, and the absorption heat pump 9 outputs heat / cold water, providing heating in winter and cooling in summer.

[0023] Certainly, the above description is not limited to the above examples. The technical features not described in the present utility model can be realized by or adopted from the prior art, and will not be elaborated herein. The above embodiments and the accompanying drawings are only used to illustrate the technical solution of the present utility model and are not a limitation to the present utility model. The present utility model has been described in detail with reference to the preferred embodiments. Those of ordinary skill in the art should understand that any changes, modifications, additions or substitutions made by those of ordinary skill in the art within the scope of the essence of the present utility model do not depart from the purpose of the present utility model and should also fall within the scope of protection of the claims of the present utility model.

Claims

1. A compressed air energy storage system for combined cooling, heating and power supply with a coupled absorption heat pump, comprising an air storage tank (4), several stages of air compression units connected to the input end of the air storage tank, and several stages of air expansion units connected to the output end of the air storage tank, characterized in that: It further includes a heat exchange unit and a waste heat utilization unit. The heat exchange unit includes a normal temperature water tank (3) and a high temperature water tank (5). The first medium input ends of the several-stage air compression units are all connected to the output end of the normal temperature water tank (3), and the first medium output ends of the several-stage air compression units are all connected to the input end of the high temperature water tank (5). The second medium input ends of the several-stage air expansion units are all connected to the output end of the high temperature water tank (5); The waste heat utilization unit includes a medium temperature water tank (8) and an absorption heat pump (9). The second medium output ends of the several-stage air expansion units are all connected to the input end of the medium temperature water tank (8), and the output end of the medium temperature water tank (8) is connected to the input end of the absorption heat pump (9).

2. The compressed air energy storage system for combined cooling, heating and power supply of a coupled absorption heat pump according to claim 1, wherein: The number of stages of the several-stage air compression units is 4 to 8 stages.

3. A compressed air energy storage system for combined cooling, heating and power supply by a coupled absorption heat pump according to claim 1, characterized in that: The air compression unit includes an air compressor (1) and an inter-stage cooler (2) connected in sequence along the compressed air conveying direction. The inter-stage cooler (2) is provided with a first medium input end and a first medium output end.

4. A compressed air energy storage system for combined cooling, heating and power supply with a coupled absorption heat pump according to claim 1, characterized in that: The number of stages of the several-stage air expansion units is 2 to 4 stages.

5. A compressed air energy storage system for combined cooling, heating and power supply with a coupled absorption heat pump according to claim 1, characterized in that: The air expansion unit includes an inter-stage heater (6) and an air turbine (7) connected in sequence along the compressed air conveying direction. The inter-stage heater (6) is provided with a second medium input end and a second medium output end.

6. A compressed air energy storage system for combined cooling, heating and power supply with a coupled absorption heat pump according to claim 1, characterized in that: The high temperature water tank is a pressure-bearing water storage floating roof tank.

Images