CO2 heat pump system waste heat efficient utilization elastic energy storage device

Abstract

A CO2 heat pump system waste heat efficient utilization elastic energy storage device comprises a heat pump circulation system and an elastic energy storage system, a ventilation pipeline is connected between the heat pump circulation system and the elastic energy storage system, and the heat pump circulation system comprises a compressor generating waste heat and an evaporator generating waste cold. The waste heat and the waste cold can enter the elastic energy storage system through the ventilation pipeline; the elastic energy storage system comprises a power transmission device and an elastic energy storage device, the elastic energy storage device comprises a plurality of springs, and when waste heat enters the elastic energy storage device, the power transmission device operates and compresses the springs to enable the springs to be in a compressed state; when residual cold enters the elastic energy storage device, the spring in the compressed state releases elastic potential energy, and the elastic potential energy is converted into kinetic energy used for driving the heat pump circulation system to operate through the power transmission device. The energy utilization efficiency of the CO2 heat pump system can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO2 heat pump systems, and in particular relates to a flexible energy storage device for efficiently utilizing waste heat of a CO2 heat pump system. Background Art

[0002] CO2 heat pump technology is a heat pump technology that uses CO2 as a refrigerant. It is non-flammable, non-toxic, has no irritating odor, has zero ozone depletion ability, and has a negligible greenhouse effect. It is harmless to the environment and can be recycled from industrial production. Therefore, it has gradually become a widely used heat pump technology.

[0003] When a CO2 heat pump system is operating as a heating system, it absorbs heat from a low-temperature heat source. After being compressed by the compressor, the CO2 refrigerant's temperature and pressure rise, releasing heat to the high-temperature heat source in the condenser to generate heat. During this process, components such as the compressor and condenser generate a significant amount of heat. If this heat is not fully utilized and is directly discharged into the environment, it becomes waste heat. The CO2 refrigerant in the CO2 heat pump system evaporates in the evaporator, absorbing heat and lowering the evaporator's surface temperature. This absorbs heat from the room, achieving cooling. At this time, the temperature of the air or other medium surrounding the evaporator also drops. If this cooling capacity is not fully utilized and is directly dissipated into the environment, it becomes waste cooling.

[0004] While existing technologies have made some progress in utilizing waste heat from CO2 heat pump systems, they still face numerous shortcomings. Most solutions only achieve a single function, such as using waste heat from a single CO2 heat pump system for water heating. These solutions lack the ability to utilize multiple functions, resulting in low energy efficiency. Summary of the Invention

[0005] The present invention provides a flexible energy storage device for efficiently utilizing waste heat of a CO2 heat pump system, so as to solve the problem of low energy utilization efficiency of the CO2 heat pump system.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: A CO2 heat pump system waste heat efficient utilization elastic energy storage device, comprising a heat pump circulation system and an elastic energy storage system, wherein a ventilation duct is connected between the heat pump circulation system and the elastic energy storage system, the heat pump circulation system comprises a compressor for generating waste heat and an evaporator for generating waste cold, and the waste heat and waste cold can enter the elastic energy storage system through the ventilation duct; The elastic energy storage system includes a power transmission device and an elastic energy storage device. The elastic energy storage device includes several springs. When residual heat enters the elastic energy storage device, the power transmission device operates and compresses the springs so that the springs are in a compressed state; when residual cold enters the elastic energy storage device, the springs in the compressed state release elastic potential energy and convert the elastic potential energy into kinetic energy for driving the operation of the heat pump circulation system through the power transmission device. Furthermore, the elastic energy storage device includes two heat-insulating boxes arranged opposite to each other, wherein a rotatable turntable is provided in the heat-insulating box, and a plurality of sleeves are fixed circumferentially on the turntable, and a spring is provided in each sleeve; The power transmission device is used to push the spring to be compressed into the sleeve, and the spring can be locked with the sleeve; or the spring releases elastic potential energy to push the power transmission device to operate.

[0007] Furthermore, the power transmission device includes an electric motor, a transmission gear set and a crank-connecting rod mechanism, wherein the electric motor is used to drive the transmission gear set, and the crank-connecting rod mechanism is connected to the transmission gear set; The crank-connecting rod mechanism includes a reciprocating force application rod, and two ends of the force application rod are respectively used to compress the springs in the two heat preservation boxes.

[0008] Furthermore, a set of parallel plates is fixed to the side wall of the heat preservation box, the parallel plates pass through the side wall of the heat preservation box, and one end surface of the parallel plates is spaced from the end surface of the sleeve; Pistons are fixed at both ends of the force application rod, and the pistons move back and forth along the parallel plates.

[0009] Furthermore, a spring top cover is fixed to the free end of each spring, and an automatic buckle is installed on the inner wall of the sleeve. After the spring is compressed, the spring top cover is buckled with the automatic buckle; when the elastic energy storage system releases elastic potential energy, the automatic buckle is disconnected from the spring top cover.

[0010] Furthermore, connecting rods are connected between the motor and the transmission gear set, as well as between the transmission gear set and the compressor. A clutch is provided on the connecting rod, and the clutch controls the transmission gear set to be connected only to the motor, or only to the compressor.

[0011] Furthermore, the air inlet end of the ventilation duct is connected to the compressor and the evaporator respectively, and the air outlet end of the ventilation duct is connected to the two insulation boxes at the same time; A three-way valve is provided on the ventilation duct, and the three-way valve controls the ventilation duct to be in communication only with the compressor or the evaporator.

[0012] Furthermore, an air outlet is provided on a side wall of the thermal insulation box, and an inner wall of the thermal insulation box is filled with thermal insulation material.

[0013] Furthermore, the thermal insulation material is one of polystyrene foam, polyurethane foam, and extruded polystyrene foam.

[0014] Furthermore, the heat pump circulation system further includes a condenser, and the condenser is connected to a water tank system; The water tank system includes a water tank and a water pump. The water pump is used to drive the water in the water tank to circulate between the water tank and the condenser to absorb the waste heat generated by the condenser.

[0015] The present invention can achieve the following beneficial effects: 1. The present invention combines the recovered waste heat in the heat pump circulation system with an elastic energy storage system. It utilizes low-grade green energy such as wind, hydro, and solar energy that cannot be directly connected to the grid. The system stores energy when the elastic modulus is low at high temperatures and releases energy when the elastic modulus is high at low temperatures, thereby increasing elastic potential energy and achieving efficient utilization of waste heat from the CO2 heat pump system. This system has the advantages of improving comprehensive energy utilization and reducing operating costs. 2. This application also provides a water tank system, through which the water circulation of the water tank system can realize the recovery and utilization of the heat inside the condenser; 3. The elastic energy storage system of the present application can simultaneously utilize the waste heat and waste cold in the heat pump circulation system to change the elastic modulus of the spring, and through the elastic energy storage system, realize multiple conversions of the energy in the waste heat and waste cold into energy forms, and transfer them to the compressor for use as the operating kinetic energy of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of a system for a CO2 heat pump system waste heat efficient utilization elastic energy storage device according to the present invention; Figure 2 Detailed schematic diagram of the elastic energy storage system of the present invention; Figure 3 It is a front view of the turntable of the present invention.

[0017] In the accompanying drawings, the components represented by the reference numerals are as follows: 1. Compressor; 2. Condenser; 3. High-pressure valve; 4. Dry filter; 5. Buffer tank; 6. Solenoid valve; 7. Throttle valve; 8. Evaporator; 9. Fan; 10. Gas-liquid separator; 11. Water tank; 12. Water pump; 13. Motor; 14. Connecting rod; 15. Transmission gear set; 16. Turntable; 17. Insulation box; 171. Air outlet; 18. Crank-connecting rod mechanism; 181. Force transmission rod; 182. Force application rod; 183. Piston; 19. Parallel plate; 20. Sleeve; 21. Spring; 22. Clutch; 23. Ventilation duct; 24. Three-way valve; 25. Automatic snap fastener; 26. Spring top cover. DETAILED DESCRIPTION

[0018] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0019] like Figures 1 to 3 As shown, a flexible energy storage device for efficiently utilizing waste heat of a CO2 heat pump system includes a heat pump circulation system, a water tank system and a flexible energy storage system. The heat pump circulation system is used to realize the CO2 heat pump circulation, the water tank system is used to realize the recovery of heat in the condenser 2, and the flexible energy storage system is used to realize the recovery of waste heat of the compressor 1 and waste cold of the evaporator 8.

[0020] The heat pump circulation system includes a compressor 1, a condenser 2, a high-pressure valve 3, a filter drier 4, a buffer tank 5, a solenoid valve 6, a throttle valve 7, an evaporator 8, a fan 9, and a gas-liquid separator 10. The various components in the heat pump circulation system are connected together through refrigerant pipes: the compressor 1 is connected to the condenser 2, the condenser 2 is connected to the high-pressure valve 3, the high-pressure valve 3 is connected to the filter drier 4, the filter drier 4 is connected to the buffer tank 5, the buffer tank 5 is connected to the solenoid valve 6, the solenoid valve 6 is connected to the throttle valve 7, the throttle valve 7 is connected to the evaporator 8, the fan 9 is placed on one side of the evaporator 8, and the evaporator 8 is connected to the gas-liquid separator 10.

[0021] When the heat pump circulation system is operating, the pressure of liquid CO2 decreases within evaporator 8, causing it to vaporize and absorb heat from an external low-temperature heat source, transforming from a liquid into a low-temperature, low-pressure gaseous CO2. The CO2 flowing out of evaporator 8 is a mixture of gas and liquid, and is separated into gas and liquid phases by gas-liquid separator 10. The low-temperature, low-pressure gaseous CO2 is drawn into compressor 1. After compression by compressor 1, the pressure and temperature of the gas rise sharply, transforming it into high-temperature, high-pressure gaseous CO2. This high-temperature, high-pressure gaseous CO2 enters condenser 2, where it exchanges heat with the cool water in the water pipes, releasing a large amount of heat and re-liquefying the gaseous CO2. When the pressure of the high-pressure liquid CO2 after liquefaction in condenser 2 exceeds the set opening pressure of high-pressure valve 3, valve 3 automatically opens, releasing some of the CO2 to the low-pressure side or other designated safe area.

[0022] Condenser 2 condenses gaseous CO2 into liquid form. During this process, impurities may enter the CO2. Filter drier 4 promptly removes these impurities, protecting the normal operation of condenser 2 and preventing impurities from entering subsequent components along with the CO2. During system operation, the load on condenser 2 and evaporator 8 also fluctuates with ambient temperature and user demand.

[0023] By balancing the CO2 flow, the buffer tank 5 enables the condenser 2 and evaporator 8 to operate under relatively stable conditions, improving their efficiency and service life. The solenoid valve 6 adjusts the CO2 flow and pressure based on the system load, enabling the throttling device to throttle and reduce the pressure of the CO2 under stable conditions. Throttling and reducing the pressure through the throttling valve 7 rapidly reduces the pressure and temperature, transforming the CO2 into low-temperature, low-pressure liquid CO2, ready for the next cycle.

[0024] The water tank system includes a water tank 11 and a water pump 12. The water tank system is connected to the condenser 2. Specifically, the condenser 2, the water tank 11, and the water pump 12 are interconnected via water pipes. The water pump 12 operates in a circular motion, driving cold water in the water pipes through the condenser 2. The water is heated by the condenser 2 and then flows into the water tank 11 for storage. The waste heat generated within the condenser 2 is then recovered through the water tank system.

[0025] The elastic energy storage system includes a power transmission device and an elastic energy storage device. The power transmission device includes an electric motor 13, a connecting rod 14, and a transmission gear set 15. The transmission gear set 15 is connected to both the electric motor 13 and the compressor 1 via the connecting rod 14. Specifically, the electric motor 13 is connected to the transmission gear set 15 via the connecting rod 14, and the compressor 1 is connected to the transmission gear set 15 via the connecting rod 14. A clutch 22 is connected to the connecting rod 14, which controls the engagement and disengagement between the electric motor 13 and the transmission gear set 15, as well as the engagement and disengagement between the compressor 1 and the transmission gear set 15.

[0026] The elastic energy storage device includes two symmetrically arranged insulation boxes 17, and a crank-connecting rod mechanism 18 arranged between the two insulation boxes 17. The inner wall of the insulation box 17 is filled with insulation material, and the insulation material can specifically be one of polystyrene foam, polyurethane foam, and extruded polystyrene foam. An air outlet 171 is provided on the side wall of the insulation box 17, and a turntable 16 is provided inside the insulation box 17. A sleeve 20 is fixed on the turntable 16, and a spring 21 is provided in the sleeve 20. One end of the spring 21 is fixed to the surface of the turntable 16, and the other end extends out of the end face of the sleeve 20. A spring top cover 26 is fixed to the end of the spring 21 extending out of the sleeve 20, and an automatic snap 25 is installed on the side wall of the sleeve 20.

[0027] The crank-connecting rod mechanism 18 includes a force transmission rod 181 and a force application rod 182. The force transmission rod 181 is connected to the transmission gear set 15, converting the rotational force of the transmission gear set 15 into a swinging force of the force transmission rod 181, thereby driving the force application rod 182 to move back and forth horizontally. Pistons 183 are connected to both ends of the force application rod 182, and a group of parallel plates 19 are fixed to the side wall of the insulation box 17. The parallel plates 19 pass through the side wall of the insulation box 17, and one end face of the parallel plates 19 is spaced from the end face of the sleeve 20. The parallel plates 19 are made of metal material, specifically one of a stainless steel plate, a heat-resistant steel plate, a nickel-based alloy plate, and a titanium alloy plate. The piston 183 is located between a group of parallel plates 19, and the piston 183 slides back and forth along the parallel plates 19, and the compression of the spring 21 is achieved by the movement of the piston 183.

[0028] In one specific embodiment, the spring 21 and sleeve 20 are fixed to the turntable 16. Each turntable 16 is equipped with eight springs 21 and eight sleeves 20. Each sleeve 20 and spring 21 are arranged in a circular pattern at a 45° angle. The spring 21 moves within the sleeve 20. A spring top cover 26 is fixed to the top of the spring 21. An automatic snap 25 is installed within the sleeve 20. When the spring 21 is compressed to the position of the automatic snap 25, the spring top cover 26 is locked by the automatic snap 25, and the spring energy storage system completes a spring potential energy storage. It should be noted that this embodiment only uses eight springs 21 as an example for description. The specific design number of springs 21 is designed according to specific needs. The springs 21 are energy storage springs 21 and are made of metal material, which can be one of carbon springs, alloy spring steel, stainless steel spring steel, copper alloy spring material, and nickel alloy spring material.

[0029] A ventilation duct 23 is provided between the compressor 1, the evaporator 8, and the elastic energy storage device. This duct connects the compressor 1 to the insulation box 17, and the evaporator 8 to the insulation box 17. Specifically, the air inlet of the ventilation duct 23 connects to both the compressor 1 and the evaporator 8, while the air outlet of the ventilation duct 23 connects to both insulation boxes 17. A three-way valve 24 is provided within the ventilation duct 23 to control whether the insulation box 17 connects only to the compressor 1 or only to the evaporator 8.

[0030] During the day, the connection between evaporator 8 and insulation box 17 is closed via three-way valve 24, and compressor 1 is connected to insulation box 17. The residual heat from compressor 1 flows through ventilation duct 23, via three-way valve 24, and driven by fan 9 into insulation box 17, thereby heating spring 21. After spring 21 is fully heated, the residual heat and exhaust gas are discharged through air outlet 171.

[0031] At the same time, the elastic energy storage system operates, and low-grade energy sources such as wind, hydro, and solar energy that cannot be directly connected to the grid provide energy for motor 13. Motor 13 drives the transmission gear set 15 at the other end to rotate through connecting rod 14. At this time, compressor 1 and transmission gear set 15 are disconnected. Transmission gear set 15 drives crank-connecting rod mechanism 18 to operate, and piston 183 reciprocates under the action of crank-connecting rod mechanism 18. Driven by connecting rod 14, piston 183 pushes spring 21 to compress. After the spring top cover 26 contacts the automatic snap 25 in sleeve 20, the automatic snap 25 closes, storing energy in spring 21. The rotation of turntable 16 causes each spring 21 to store energy in turn.

[0032] At night, the connection between the compressor 1 and the insulation box 17 is closed through the three-way valve 24, and the evaporator 8 is connected to the insulation box 17. Driven by the fan 9, the cold air from the evaporator 8 enters the insulation box 17 through the three-way valve 24 to cool the spring 21. At this stage, the elastic energy storage system releases elastic potential energy, and the connecting rod 14 connected to the output end of the motor 13 is separated from the transmission gear set 15 under the action of the clutch 22. The connecting rod 14 connected to the compressor 1 is engaged with the transmission gear set 15 under the action of the clutch 22; the sleeve 20 and spring 21 on the turntable 16 rotate to a position aligned with the parallel plate 19, the automatic buckle 25 opens, the spring 21 pushes the piston 183, and the spring 21 turntable 16 converts the elastic potential energy of the spring 21 into kinetic energy through the action of the crank-connecting rod mechanism 18 and transmits it to the compressor 1. Among them, the connection between the automatic buckle 25 and the spring top cover 26 can be locked and unlocked by electromagnetic force.

[0033] The elastic modulus of spring 21 decreases under the high temperature and residual heat of compressor 1, making it more susceptible to compression. Motor 13 transfers kinetic energy to the crankshaft mechanism 18, compressing spring 21 and converting it into elastic potential energy. The elastic modulus of spring 21 increases under the influence of cold air from evaporator 8, releasing spring 21 and converting its elastic potential energy into kinetic energy. Because the energy storage process occurs at high temperatures, the elastic modulus of spring 21 decreases, storing the elastic potential energy. The energy release process occurs at low temperatures, increasing the elastic modulus and the elastic potential energy, thereby increasing the elastic potential energy.

[0034] At night, when utility electricity prices are low, the motor 13 can convert electrical energy into mechanical energy, which is then deformed by the transmission mechanism to store the electrical energy as elastic potential energy. During the day, when utility electricity prices are higher, the spring 21 releases the stored elastic potential energy, which is then driven by the transmission mechanism to operate the compressor 1, converting the elastic potential energy into kinetic energy, thus providing a power source for the heat pump circulation system.

[0035] The heat pump circulation system, water tank system, and elastic energy storage system interact with each other. The heat pump circulation system provides heat for the water tank system circulation. The elastic energy storage system's energy source during energy storage is the mains electricity; during energy release, the energy source is the kinetic energy converted from elastic potential energy.

[0036] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A CO2 heat pump system waste heat efficient utilization elastic energy storage device, characterized by: The invention comprises a heat pump circulation system and an elastic energy storage system, wherein a ventilation duct (23) is connected between the heat pump circulation system and the elastic energy storage system, the heat pump circulation system comprises a compressor (1) for generating waste heat and an evaporator (8) for generating waste cold, and the waste heat and waste cold can enter the elastic energy storage system through the ventilation duct (23); The elastic energy storage system includes a power transmission device and an elastic energy storage device, the elastic energy storage device includes a plurality of springs (21), and when residual heat enters the elastic energy storage device, the power transmission device operates and compresses the springs (21) so that the springs (21) are in a compressed state; When the residual cold enters the elastic energy storage device, the spring (21) in the compressed state releases elastic potential energy, and converts the elastic potential energy into kinetic energy for driving the heat pump circulation system through the power transmission device.

2. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 1, characterized in that: The elastic energy storage device comprises two heat-insulating boxes (17) arranged opposite to each other, wherein a rotatable turntable (16) is provided in the heat-insulating box (17), and a plurality of sleeves (20) are fixed circumferentially on the turntable (16), and a spring (21) is provided in each sleeve (20); The power transmission device is used to push the spring (21) to be compressed into the sleeve (20), and the spring (21) can be locked with the sleeve (20); or the spring (21) releases elastic potential energy to push the power transmission device to operate.

3. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 2, characterized in that: The power transmission device comprises an electric motor (13), a transmission gear set (15) and a crank-connecting rod mechanism, wherein the electric motor (13) is used to drive the transmission gear set (15), and the crank-connecting rod mechanism is connected to the transmission gear set (15); The crank-connecting rod mechanism comprises a reciprocating force application rod (182), wherein both ends of the force application rod (182) are respectively used to compress springs (21) in two heat preservation boxes (17).

4. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 3, characterized in that: A group of parallel plates (19) are fixed to the side wall of the heat preservation box (17), the parallel plates (19) pass through the side wall of the heat preservation box (17), and one end surface of the parallel plates (19) is spaced from the end surface of the sleeve (20); Pistons (183) are fixed to both ends of the force application rod (182), and the pistons (183) reciprocate along the parallel plates (19).

5. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 2, characterized in that: A spring top cover (26) is fixed to the free end of each spring (21), and an automatic buckle (25) is installed on the inner wall of the sleeve (20). After the spring (21) is compressed, the spring top cover (26) is buckled with the automatic buckle (25); when the elastic energy storage system releases elastic potential energy, the automatic buckle (25) is disconnected from the spring top cover (26).

6. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 3, characterized in that: A connecting rod (14) is connected between the motor (13) and the transmission gear set (15), as well as between the transmission gear set (15) and the compressor (1). A clutch (22) is provided on the connecting rod (14). The clutch (22) controls the transmission gear set (15) to be connected only to the motor (13) or only to the compressor (1).

7. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 2, characterized in that: The air inlet end of the ventilation duct (23) is connected to the compressor (1) and the evaporator (8) respectively, and the air outlet end of the ventilation duct (23) is simultaneously connected to the two insulation boxes (17); A three-way valve (24) is provided on the ventilation duct (23), and the three-way valve (24) controls the ventilation duct (23) to communicate only with the compressor (1) or the evaporator (8).

8. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 2, characterized in that: An air outlet (171) is provided on a side wall of the heat preservation box (17), and an inner wall of the heat preservation box (17) is filled with heat preservation material.

9. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 8, characterized in that: The thermal insulation material is one of polystyrene foam, polyurethane foam and extruded polystyrene foam.

10. The CO2 heat pump system waste heat efficient utilization elastic energy storage device according to claim 1, characterized in that: The heat pump circulation system further comprises a condenser (2), wherein the condenser (2) is connected to a water tank (11) system; The water tank (11) system comprises a water tank (11) and a water pump (12), wherein the water pump (12) is used to drive the water in the water tank (11) to circulate between the water tank (11) and the condenser (2) to absorb waste heat generated by the condenser (2).

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