Novel solar injection-compression composite heating / cooling system

Abstract

The invention provides a novel solar injection-compression composite heating / cooling system which mainly comprises a solar heat collection unit, an injection type refrigeration unit, a compression type circulation unit and a hot water supply unit, and the solar heat collection unit comprises an inverter, a PV / T heat collector, a first heat storage water tank and a phase change energy storage element. The solar heat collection unit is used for absorbing energy in solar radiation and converting the energy into electric energy and heat energy. The jet type refrigeration unit comprises an ejector, a heat exchanger, a gas-liquid separator and a liquid storage device. The injection type refrigeration unit is used for being combined with the compression type circulation unit for refrigeration in summer to meet the building cold load. The compression type circulation unit comprises a compressor, a throttling valve and a second heat storage water tank. The compression type circulation unit and the jet type refrigeration unit carry out load refrigeration in summer, and the hot water supply unit is used for providing domestic hot water energy consumption of a building all the year round.

Description

Technical Field

[0001] This invention relates to the field of solar heat pump technology. Specifically, it relates to a novel solar jet-compression hybrid heating / cooling system. Background Technology

[0002] Currently, the energy market faces tremendous opportunities and challenges, and energy conservation and carbon reduction have become a hot topic of social concern. Traditional fossil fuels, due to their non-renewability, low utilization efficiency, and severe environmental pollution, can no longer meet the needs of today's sustainable development. Against this backdrop, accelerating energy transition, developing clean energy, promoting the cascade utilization of energy systems, and improving energy efficiency are imperative.

[0003] Clean heating in rural areas of northern my country is an important part of the country's energy transition. In recent years, relevant national departments have implemented coal-to-electricity and coal-to-gas conversions, actively exploring and promoting various energy utilization methods such as air source heat pumps and solar energy. However, the energy efficiency ratio of air source heat pumps decreases significantly with decreasing temperatures in winter, leading to increased power consumption. Solar energy, as the world's largest renewable clean energy source, has good economic and environmental benefits, but its solar resources are affected by meteorological conditions, exhibiting intermittency and instability. This results in unstable operating efficiency for solar-powered systems and a mismatch between system energy demand and solar energy supply. Furthermore, air conditioning performance degrades in high summer temperatures. Currently, most solar heat pump systems are only used for heating, leaving the equipment idle in summer and resulting in low economic efficiency. Solar jet refrigeration technology has attracted widespread attention in the industry due to its simple structure, low cost, and ability to utilize low-grade heat energy. The advantages of refrigeration systems combining solar jet refrigeration with other refrigeration methods are particularly prominent.

[0004] Therefore, how to fully utilize solar energy resources and overcome its shortcomings in solar heat pump systems, as well as how to integrate cooling, heating and hot water production functions, is an urgent problem to be solved.

[0005] Application content

[0006] To address the aforementioned problems and the shortcomings of existing technologies, this invention proposes a novel solar jet-compression composite heating / cooling system. This system enables more efficient utilization of solar energy in solar heat pump systems and integrates the three functions of cooling, heating, and hot water supply, offering advantages such as high solar energy utilization and high housing comfort.

[0007] A novel solar-powered jet-compression composite heating / cooling system mainly includes: 1. Inverter; 2. PV / T collector (2); 3-1 to 3-4. Shut-off valve; 4. First hot water storage tank; 5. Gas-liquid separator; 6-1 to 6-6. Water pump; 7-1 to 7-5. Three-way valve; 8. Ejector; 9. Heat exchanger; 10. Liquid storage tank; 11. Phase change energy storage element; 12. Compressor; 13. Four-way reversing valve; 14. Second hot water storage tank; 15-1 to 15-2. Throttling valve; 16. Filter; 17. Domestic hot water supply.

[0008] A novel solar-jet-compression composite heating / cooling system mainly includes a solar collector unit, a jet cooling unit, a compression circulation unit, and a hot water supply unit;

[0009] The solar thermal collector unit includes an inverter, a PV / T collector (2), a first hot water storage tank, and a phase change energy storage element. The solar thermal collector unit is used to absorb energy from solar radiation and convert it into electrical energy and thermal energy.

[0010] The jet-type refrigeration unit includes an ejector, a heat exchanger, a gas-liquid separator, and a liquid receiver. The jet-type refrigeration unit is used in conjunction with a compression-type cycle unit to meet the building's cooling load during the summer.

[0011] The compression circulation unit includes a compressor, a throttle valve, and a second hot water storage tank. In addition to cooling the building under load with the jet refrigeration unit in summer, the compression circulation unit can also use the heat from the first hot water storage tank and the phase change energy storage element as a low-temperature heat source in winter, and then use the heat from these elements to provide heating for the building via a heat pump.

[0012] The hot water supply unit is used to provide the building's annual domestic hot water energy consumption.

[0013] The outlet of the PVT collector is connected to the inlet of the first hot water storage tank. The first pair of outlets of the first hot water storage tank are connected to the inlet of the phase change energy storage element. The outlet of the phase change energy storage element is connected to the inlet of the PVT collector, thus completing the solar thermal storage cycle 1. The outlet of the first hot water storage tank is also connected to the inlet of the PVT collector, thus completing the solar thermal storage cycle 2.

[0014] Furthermore, the outlet of the heat exchange coil in the first hot water storage tank is connected to the working fluid inlet of the heat pump compressor. The working fluid outlet of the heat pump compressor is connected to the working fluid inlet of the heat exchanger, the working fluid outlet of the heat exchanger is connected to the working fluid inlet of the throttle valve, and the working fluid outlet of the throttle valve is connected to the inlet of the first hot water storage tank, thus completing the heat storage and utilization heat pump cycle in the water tank.

[0015] Furthermore, the working fluid outlet of the phase change energy storage element is connected to the working fluid inlet of the heat pump compressor. The working fluid outlet of the heat pump compressor is connected to the working fluid inlet of the heat exchanger, the working fluid outlet of the heat exchanger is connected to the working fluid inlet of the throttle valve, and the working fluid outlet of the throttle valve is connected to the working fluid inlet of the phase change energy storage element, thus completing the phase change heat storage utilization heat pump cycle.

[0016] Furthermore, the hot water in the first hot water storage tank is heated and flows into the tank. After the refrigerant in the heat exchanger is converted into vapor, it passes through a gas-liquid separator and enters the ejector. The high vapor velocity depressurizes and vaporizes the refrigerant in the phase change energy storage element, simultaneously lowering the temperature of the phase change energy storage element. The gas from the gas-liquid separator and the gas from the phase change energy storage element mix in the ejector and enter the condenser of the jet refrigeration unit. After releasing heat, the mixture passes through a liquid receiver, where it splits into two paths. One path is pressurized by a water pump and returned to the first hot water storage tank for heating, while the other path is throttled and returned to the phase change energy storage element for further evaporation. This completes the jet refrigeration cycle.

[0017] Furthermore, the refrigerant outlet of the phase change energy storage element is connected to the refrigerant inlet of the throttle valve, the refrigerant outlet of the throttle valve is connected to the refrigerant inlet of the internal heat exchanger of the second hot water storage tank, the refrigerant outlet of the internal heat exchanger of the second hot water storage tank is connected to the compressor, and the refrigerant outlet of the compressor is connected to the working fluid inlet of the phase change energy storage element, thus completing the refrigeration cycle.

[0018] Furthermore, the replenishment water for the hot water supply first passes through a water pump and then through a Y-type filter to prevent excessive scale buildup in the first hot water storage tank and extend its service life. The filtered water is first heated by a jet-type condenser, and then enters the first hot water storage tank through the second pair of inlets for a second heating. After being heated in stages, the water is supplied to residents for domestic hot water.

[0019] As a preferred option, different system operation modes are matched according to the intensity of solar radiation and heating demand. During the heating season, the solar thermal system operates in a solar thermal cycle, prioritizing the use of heat from the first hot water storage tank as a low-temperature heat source for the heat pump. When the heat in the first hot water storage tank gradually decreases and its temperature falls below the melting point of the phase change energy storage element, the phase change energy storage heat pump mode is activated. During summer cooling, the solar thermal system operates in a solar thermal cycle. When cooling is required in summer, jet cooling is activated to provide cooling capacity to the phase change energy storage element, serving as a low-temperature cold source for the compression cooling cycle heat pump. Flexible adjustment of these modes can improve the utilization rate of solar thermal energy and enhance home comfort.

[0020] As a preferred option, different system operation modes can be matched according to the season, the intensity of solar radiation, and heating demand to improve the utilization rate of solar thermal energy.

[0021] As a preferred option, the solar thermal storage element is equipped with a hot water storage tank and a low-temperature phase change thermal storage element. The hot water that has absorbed solar heat passes through the two energy storage elements in sequence, so as to utilize the heat in a cascade manner.

[0022] Preferably, the first hot water storage tank includes two inlets and two outlets, and the internal heat exchange coil serves as the evaporator / condenser of the heat pump, which can reduce heat loss and simplify the structure.

[0023] As a preferred option, water in the hot water storage tank is the heat storage material. Water has a large specific heat capacity, cools down slowly, and can store heat well. In addition, water has little pollution to the environment and is safe to use.

[0024] Preferably, the phase change material of the phase change energy storage element has a melting point temperature of 15-20℃, which is beneficial to the overall efficiency of the system as a low-grade energy supply during the cooling and heating seasons.

[0025] As a preferred option, the phase change material of the phase change energy storage element is KF·4H2O. The phase change material has a phase change temperature of 18.5℃. This phase change energy storage material is an inorganic hydrated salt, which has a wide range of applications, is relatively inexpensive, and has a large heat storage density per unit volume.

[0026] As a preferred option, the phase change energy storage element is a three-channel heat exchange device. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a novel solar-powered jet-compression composite heating / cooling system.

[0028] Figure 2 This is a new type of summer operation mode for solar jet-compression composite heating / cooling systems.

[0029] Figure 3 It is a new type of solar thermal cycle for the summer operation mode of a solar jet-compression composite heating / cooling system.

[0030] Figure 4 It is a new type of solar jet-compression composite heating / cooling system with a jet-type refrigeration cycle for summer operation.

[0031] Figure 5 It is a compression refrigeration cycle for the summer operation mode of a novel solar jet-compression composite heating / cooling system.

[0032] Figure 6 It is a new type of solar jet-compression composite heating / cooling system operating mode for the heating season.

[0033] Figure 7It is a new type of solar thermal cycle for the heating season operation mode of a solar jet-compression composite heating / cooling system.

[0034] Figure 8 This is a new type of solar jet-compression composite heating / cooling system that utilizes a heat pump to circulate heat from the water tank during the heating season.

[0035] Figure 9 It is a novel solar jet-compression composite heating / cooling system that utilizes phase change thermal storage and heat pump circulation for the heating season operation mode.

[0036] Figure 10 This is a schematic diagram of the domestic hot water supply circuit for a novel solar-powered jet-compression composite heating / cooling system.

[0037] Figure 11 This is a schematic diagram of the first hot water storage tank of a novel solar jet-compression composite heating / cooling system.

[0038] In the figure: 1. Inverter; 2. PV / T collector (2); 3-1 to 3-4. Shut-off valve; 4. First hot water storage tank; 5. Gas-liquid separator; 6-1 to 6-6. Water pump; 7-1 to 7-5. Three-way valve; 8. Ejector; 9.

[0039] 10. Heat exchanger; 11. Liquid receiver; 12. Phase change energy storage element; 13. Compressor; 14. Four-way reversing valve.

[0040] Second hot water storage tank; 15-1~15-2. Throttling valve; 16. Filter; 17. Domestic hot water supply. Detailed Implementation

[0041] There are five operating modes: solar thermal storage mode 1, solar thermal storage mode 2, energy storage element heating mode, cooling mode, and hot water supply mode.

[0042] Solar thermal storage mode 1: During the heating season when there is sufficient sunlight, the first shut-off valve 3-1, water pump 6-2 and the first three-way valve 7-1b are opened. At this time, the circulating water passes through the PV / T collector 2 and absorbs the heat therein. The hot water enters the first hot water storage tank 4 from the collector outlet. After the hot water is cooled once, it enters the phase change energy storage element 11 for a second cooling. The circulating water then enters the collector from the phase change energy storage element outlet.

[0043] Solar thermal storage mode 2: When there is sufficient sunlight for cooling in summer, the first shut-off valve 3-1, water pump 6-1 and the first three-way valve 7-1a are opened. After the circulating water enters the PV / T collector 2 to absorb the heat of the solar energy, the hot water enters the first hot water storage tank 4 to heat it. The cooled circulating water enters the PV / T collector 2 again for the next heat collection cycle.

[0044] Heating mode using energy storage elements: In winter, when solar radiation intensity is low or during cloudy / rainy weather, the system operates in heating mode using energy storage elements. When the temperature of the first hot water storage tank 4 is higher than the melting point temperature of the phase change energy storage material, three-way valves 7-4a and 7-5a are opened. At this time, the refrigerant flowing through the internal heat exchanger of the first hot water storage tank 4 absorbs heat from the first hot water storage tank and evaporates, entering the compressor 12 as a low-temperature, low-pressure superheated gas. After being heated and pressurized by the compressor 12, the superheated gas enters the internal heat exchanger of the second hot water storage tank 14 and releases heat to the water in the second hot water storage tank 14. Simultaneously, the refrigerant is condensed, becoming a high-pressure liquid at the outlet. After passing through the throttling valve 15 to reduce the pressure drop, it becomes a low-temperature, low-pressure liquid and returns to the first hot water storage tank, completing one cycle of the heat pump mode for utilizing the heat from the water tank. When the temperature of the first hot water storage tank 4 is lower than the melting point temperature of the phase change energy storage material, three-way valves 7-4b and 7-5b are opened. At this time, the refrigerant flowing through the internal heat exchanger of the phase change energy storage element 11 absorbs the heat in the phase change energy storage element and evaporates. It enters the compressor 12 in a low-temperature and low-pressure superheated gas state. After the superheated gas is heated and pressurized by the compressor 12, it enters the internal heat exchanger of the second hot water storage tank 14 and releases heat to the water in the second hot water storage tank 14. At the same time, the refrigerant is condensed and becomes a high-pressure liquid state at the outlet. After the pressure drop is throttled by the throttling valve 15, it becomes a low-temperature and low-pressure liquid state and returns to the phase change energy storage element 11, completing one cycle of the heat pump mode of heat utilization of the phase change energy storage element.

[0045] Cooling mode: When cooling is needed in summer, open the second three-way valve 7-2b, the third three-way valve 7-3b, the fourth three-way valve 7-4b, the fifth three-way valve 7-5b, and the water pump 6-6. The refrigerant flows through the water pump 6-6 and becomes a high-pressure refrigerant liquid. It enters the internal heat exchanger in the first hot water storage tank 4 and is heated into high-temperature and high-pressure steam. The steam enters the nozzle 8, expands in the nozzle 8 and flows at high speed, thus creating a low pressure at the outlet of the nozzle 8. This causes the refrigerant in the phase change energy storage element 11 to evaporate at a low temperature, providing cooling capacity for the phase change energy storage element 11. The refrigerant vapor and the refrigerant vapor generated by the phase change energy storage element 11 mix at the outlet of the nozzle 8 and enter the diffuser together. In the diffuser, the steam velocity decreases and the pressure increases. It then enters the heat exchanger 9 and is cooled into liquid refrigerant by the makeup water. The liquid water flowing out of the heat exchanger splits into two paths: one path, after being throttled and depressurized, returns to the phase change energy storage element 11 to continue evaporation and refrigeration; the other path, with increased pressure by a pump, is sent back to the internal heat exchanger of the first hot water storage tank 4 to be reheated and generate high-temperature, high-pressure steam. Jet refrigeration provides cooling capacity to the phase change energy storage element 11, which can serve as a low-temperature cold source for compression refrigeration. The refrigerant gas, compressed into high-temperature, high-pressure gas by the compressor 12, enters the phase change energy storage element 11 to absorb its cooling capacity and release heat. The refrigerant becomes a high-pressure liquid, which, after passing through the throttling valve 15, is converted into a low-temperature, low-pressure refrigerant liquid and enters the internal heat exchanger of the second hot water storage tank 14 for evaporation and refrigeration.

[0046] Hot water supply mode: In summer, the replenishment water for domestic use has a certain amount of cold water. The replenishment water is first filtered through Y-type filter 12, then heated by the condenser (heat exchanger) 9 of jet cooling, and then heated again by the first hot water storage tank 4 as domestic hot water supply.

[0047] The above five modes can be combined according to the characteristics of the environment to achieve the best results.

Claims

1. A novel solar-powered jet-compression hybrid heating / cooling system, characterized in that: The system mainly includes:

1. Inverter; 2. PV / T collector; 3-1 to 3-4. Shut-off valve; 4. First hot water storage tank; 5. Gas-liquid separator; 6-1 to 6-6. Water pump; 7-1 to 7-5. Three-way valve; 8. Ejector; 9. Heat exchanger; 10. Liquid receiver; 11. Phase change energy storage element; 12. Compressor; 13. Four-way reversing valve; 14. Second hot water storage tank; 15-1 to 15-2. Throttling valve; 16. Filter; 17. Domestic hot water supply.

2. A novel solar-powered jet-compression composite heating / cooling system according to claim 1, characterized in that, The PV / T collector (2) includes a solar panel with a heat exchange channel below it. The heat exchange channel has a heat exchange channel inlet at one end and a heat exchange channel outlet at the other end. The circulating working fluid flows through the heat exchange channel to absorb the heat generated by solar radiation. The hot water that absorbs the heat transfers the heat to the energy storage element. The cooled circulating working fluid returns to the heat exchange channel inlet to complete the solar energy storage cycle.

3. A novel solar-powered jet-compression composite heating / cooling system according to claim 2, characterized in that, The PV / T collector (2) has an optimal operating temperature. Its power generation efficiency increases first as the temperature rises. When the temperature of the PV / T collector (2) is higher than the optimal operating temperature, the heat collection efficiency decreases. The circulating working fluid of the system flows through the PV / T collector (2) and carries away its heat, which can reduce the temperature of the PV / T collector (2) and improve its power generation efficiency.

4. A novel solar-powered jet-compression composite heating / cooling system according to claim 3, characterized in that, In the solar thermal collector system, the hot water from the collector outlet passes through the first hot water storage tank (4) and the phase change energy storage element (11) in sequence, which can realize the cascade utilization of solar energy and improve the utilization rate of solar energy.

5. A novel solar-powered jet-compression composite heating / cooling system according to claim 4, characterized in that, The energy storage material in its phase change energy storage element (11) is a low-temperature phase change material with a melting point of 15-18℃. During the heating season, after the solar thermal storage cycle, its temperature is higher than the outdoor temperature. As a heat source for the heat pump evaporator, it is more effective than the air source heat pump. In summer, the phase change energy storage element (11) serves as the evaporator of the jet refrigeration unit. The cooling capacity of the jet refrigeration can be stored in the phase change energy storage element (11) as a low-level cold source for the compression refrigeration cycle, which improves the energy utilization rate and stability of the system.

6. A novel solar-powered jet-compression composite heating / cooling system according to claim 5, characterized in that, The first hot water storage tank (4) has two inlets and two outlets, and the internal heat exchange coil is used as the evaporator of the heat pump. The first hot water storage tank (4) is coupled with the evaporator of the heat pump. The phase change energy storage element (11) is coupled with the evaporator of the heat pump. The heat pump evaporator directly absorbs heat from the heat storage element, reducing heat exchange loss, making the structure more compact, and reducing the footprint.

7. A novel solar-powered jet-compression composite heating / cooling system according to claim 6, characterized in that, The phase change energy storage element (11) is a three-channel heat exchange element with three built-in heat exchanger channels. One heat exchanger channel carries the circulating working fluid for solar heat collection, one heat exchanger channel carries domestic water, and one heat exchanger channel carries refrigerant.

8. A novel solar-powered jet-compression composite heating / cooling system according to claim 7, characterized in that, The hot water supply unit first passes through a water pump and then through a Y-type filter to prevent excessive scale buildup in the first hot water storage tank (4) and extend its service life. The filtered water is first heated in the condenser of the jet cooling system and then enters the first hot water storage tank (4) for a second heating. After two heating cycles, the water is supplied to residents for domestic hot water.

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