CN116007092A - Hierarchical compression refrigeration/heating system and method for temperature and humidity independent air conditioning - Google Patents

Abstract

The invention discloses a hierarchical compression refrigeration/heating system and method for temperature and humidity independent air conditioning, including a solar photovoltaic photothermal unit, an energy storage/release unit and a hierarchical compression unit, the water channel of the solar photovoltaic photothermal unit and the The inlet and outlet of the water passage of the fresh air unit are connected to form a first water circulation passage, which is used to exchange heat with the fresh air passage of the fresh air unit. The passage forms a second water circulation passage, and the second water circulation passage is used to exchange heat with the air passage of the air handling unit; the present invention can realize the cascade preparation and utilization of cold energy/heat energy of air-conditioning cold and heat sources, and the cascade of multi-temperature heat energy grades Extraction and lifting, suitable as a cold and heat source for an air-conditioning system with independent temperature and humidity control.

Description

Hierarchical compression refrigeration/heating system and method for independent temperature and humidity air conditioning

technical field

The invention belongs to the technical field of heat pumps, and in particular relates to a hierarchical compression refrigeration/heating system and method for temperature and humidity independent air conditioning.

Background technique

Compared with traditional energy sources, solar energy has many advantages. It is not restricted by region. It can not only provide the heat required by users, but also has the obvious advantages of energy saving and environmental protection. However, it has disadvantages such as intermittent and unstable due to changes in sunlight intensity.

Compression heat pumps are widely used because of their advantages of meeting users' cooling and heating needs and continuous and stable operation. However, air source compression heat pumps driven by electric energy consume high-grade electric energy and do not have obvious advantages in energy saving and emission reduction. There is a problem of high operating costs due to the inability to take advantage of the difference in peak and valley electricity prices.

Due to the advantages of small volume change, good energy saving effect and easy control, phase change energy storage materials are more and more widely used in the field of energy storage. During the process of phase change, phase change materials can absorb heat from the environment, and release heat to the environment when needed, so as to achieve the purpose of energy storage and control the temperature of the surrounding environment.

The solar energy unit and the compression heat pump unit can realize energy transfer through the phase change energy storage material. An energy storage system for cooling and heating is disclosed in the prior art, which includes a compression heat pump unit, an energy storage unit, and a solar unit, etc., but it fails to make full use of solar energy in the cooling and heating process to further reduce energy consumption. The compression heat pump unit needs to use the energy storage unit to exchange energy with the solar unit, which may lead to limited cooperative functions of each unit under certain circumstances.

Contents of the invention

The invention provides a hierarchical compression refrigeration/heating system and method for temperature and humidity independent air conditioners. This scheme can realize the cascade preparation and utilization of cold energy/heat energy of air-conditioning cold and heat sources, as well as the cascade extraction and utilization of multi-temperature heat energy grades. It is suitable as a cold and heat source for an air-conditioning system with independent temperature and humidity control.

One of the objectives of the present invention is to provide a hierarchical compression refrigeration/heating system for temperature and humidity independent air conditioning, including a solar photovoltaic photothermal unit, an energy storage/release unit and a hierarchical compression unit, the solar photovoltaic photothermal unit The water passage is connected with the inlet and outlet of the water passage of the fresh air unit to form a first water circulation passage, and the first water circulation passage is used to exchange heat with the fresh air passage of the fresh air unit. The water passage of the unit forms a second water circulation passage, and the second water circulation passage is used to exchange heat with the air passage of the air handling unit;

The energy storage/release unit includes a cold energy/heat energy storage tank and a first heat exchanger and a second heat exchanger located in the cold energy/heat energy storage tank, the first heat exchanger is connected with the solar photovoltaic photothermal unit, and the second heat exchanger The heater is connected with the graded compression unit to realize the energy transfer and energy storage of the solar photovoltaic photothermal unit and the graded compression unit;

It also includes a fifth heat exchanger, the fifth heat exchanger includes a first heat exchange channel and a second heat exchange channel capable of heat exchange, both ends of the first heat exchange channel are connected to the first water circulation The two ports of the second heat exchange channel are connected to the second water circulation channel, and the first water circulation channel and the second water circulation channel can realize heat exchange through the fifth heat exchanger.

As a preferred solution, the outlet of the water channel of the fresh air unit is divided into two branches, wherein the first branch is connected with the first heat exchanger through the third control valve, and the other branch is connected with the first heat exchanger through the fourth control valve. A heat exchange channel is connected, and the outlet of the water channel of the air handling unit is divided into two branches, one of which is connected to one end of the water channel of the third heat exchanger through the fifth control valve, and the other branch is connected through the sixth control valve It is connected with the second heat exchange channel.

As a preferred solution, the solar photovoltaic photothermal unit also includes a solar heat collector, wherein the water passage inlet of the solar heat collector is connected with a branch of the outlet of the first heat exchanger through a first control valve, and the first heat exchanger Another branch of the outlet is connected with the water channel inlet of the fresh air unit through the second control valve.

As a preferred solution, the multi-stage compression heat pump unit further includes a compressor, a four-way reversing valve and a gas-liquid separator, wherein the four-way reversing valve has four ports, wherein the first port is a high-pressure air inlet, The first port is connected to the high-pressure exhaust port of the compressor, wherein the fourth port is a low-pressure exhaust port, the fourth port is connected to the low-pressure air inlet of the compressor, and the third port is connected to the third exchange port. One port of the refrigerant channel of the heat exchanger is connected, and the other port of the refrigerant channel of the third heat exchanger is divided into two branches, wherein the first branch is connected with the inlet of the first throttling part, and the first branch is connected with the inlet of the first throttling part. The outlet of the flow part is connected with the inlet of the second heat exchanger, the second branch is connected with the outlet of the fourth throttling part, the inlet of the fourth throttling part is connected with the bottom liquid outlet of the gas-liquid separator, and the second heat exchanger The outlet of the heater is connected with the inlet of the gas-liquid separator, and the top gas outlet of the gas-liquid separator is connected with the medium-pressure suction port of the compressor.

As a preferred solution, it also includes a fourth heat exchanger, one port of the refrigerant channel of the fourth heat exchanger is connected to the second port of the four-way reversing valve, and the refrigerant channel of the fourth heat exchanger The other end of the port is divided into two branches, one of which is connected to the inlet of the second heat exchanger through the third throttling part, the other branch is connected to the outlet of the second throttling part, and the second throttling part The inlet is connected with the bottom liquid outlet of the gas-liquid separator.

As a preferred solution, the compressor is a two-stage compressor, the high-pressure exhaust port of the compressor is connected to the high-pressure inlet port of the four-way reversing valve, and the low-pressure suction port of the compressor is connected to the four-way reversing valve. It is connected to the low-pressure exhaust port of the valve, and the medium-pressure suction port of the compressor is connected to the top gas outlet of the gas-liquid separator.

As a preferred solution, the compressor includes a first compressor and a second compressor, the suction port of the first compressor is connected to the discharge port of the second compressor, and the high-pressure discharge port of the first compressor is connected to the discharge port of the second compressor. The high-pressure air inlet of the four-way reversing valve is connected, the low-pressure suction port of the second compressor is connected with the low-pressure exhaust port of the four-way reversing valve, and the top of the gas-liquid separator is exhausted. The port is connected with the connecting pipeline between the first compressor and the second compressor.

As a preferred solution, the compressor includes a first compressor and a second compressor, the outlets of the first compressor and the second compressor are connected to the high-pressure inlet of the four-way reversing valve, and the The low-pressure discharge port of the four-way reversing valve is connected with the low-pressure suction port of the second compressor, and the top discharge port of the gas-liquid separator is connected with the medium-pressure suction port of the first compressor.

As a preferred solution, the solar heat collector adopts a solar PV/T heat collector, which is used to absorb solar energy and convert it into electric energy and heat energy, and provide heat energy to the fresh air unit for heating the fresh air, and also provide heat energy for heating the energy storage/release unit Phase-change materials are used to store thermal energy, and the generated electrical energy is used to drive compressors and circulation pumps.

The second object of the present invention is to provide a hierarchical compression refrigeration/heating method for temperature and humidity independent air conditioners, the solar photovoltaic photothermal unit, hierarchical compression unit and air conditioning energy storage/release unit Combined operation or independent operation under hot conditions;

The specific steps of cooling mode are as follows:

When operating in the low-temperature cooling capacity preparation and supply mode, high-temperature cooling capacity preparation storage and release supply mode, in the case of low power at night, the graded compression unit supplies cooling capacity to the cold energy/thermal energy storage tank and the air handling unit at the same time. The /thermal energy storage tank provides the low-grade cooling capacity of the fresh air unit to deal with the fresh air load, and the cold energy is provided by the dual-temperature evaporation temperature of the second heat exchanger and the third heat exchanger respectively. The phase change material cold storage process of the thermal energy storage tank is required The higher temperature cooling capacity and the lower temperature cooling capacity required by the air handling unit to deal with the wet load of humid air; the third heat exchanger of the refrigeration cycle with high compression ratio is used as a low temperature evaporator to prepare lower temperature, higher The grade cooling capacity is supplied to the air handling unit to bear latent heat load and sensible heat load, and the second heat exchanger of the refrigeration cycle with low compression ratio is used as a high-temperature evaporator to prepare higher temperature and lower grade cooling capacity, which is stored in the cold energy/ The thermal energy storage tank is also supplied to the fresh air unit to bear the fresh air load;

When operating in the low-temperature potential cooling capacity preparation supply mode and high-temperature potential cooling capacity preparation and storage mode, in the case of peak power during the day, the electric energy prepared by the solar PV/T collector is used to drive the compressor and circulation pump, and the high compression ratio The third heat exchanger of the refrigeration cycle is used as a low-temperature evaporator to prepare lower-temperature, higher-grade chilled water, which is supplied to the air handling unit to bear the latent heat load and sensible heat load, and the cooling capacity of the chilled water once used by the air handling unit is passed The fifth heat exchanger provides higher temperature and lower grade cooling capacity for the fresh air unit to bear the fresh air load; the second heat exchanger of the refrigeration cycle with low compression ratio is used as a high temperature evaporator to prepare higher temperature and lower grade The cold energy is completely stored in the cold energy/heat energy storage tank;

When operating in the mode of preparing supply of low-temperature potential cooling capacity and releasing supply of high-temperature potential cooling capacity, in the case of peak power during the day, the electric energy prepared by the solar PV/T collector is used to drive the compressor and circulation pump, and the compression ratio is low. The refrigerating cycle stops working, and only the third heat exchanger of the refrigerating cycle with high compression ratio is used as a low-temperature evaporator to prepare lower-temperature, higher-grade chilled water and supply it to the air handling unit to bear latent heat load and sensible heat load; cold energy/thermal energy storage The higher temperature cooling capacity stored in the tank is used to bear the fresh air load;

When operating in the low-temperature cold capacity preparation supply mode, the electric energy prepared by the solar PV/T collector is used to drive the compressor and the circulation pump when the cold energy/thermal energy storage tank does not store cold energy, and the low compression The refrigerating cycle with a higher compression ratio stops working, and the third heat exchanger of the refrigerating cycle with a high compression ratio is used as a low-temperature evaporator to prepare lower-temperature, higher-grade chilled water for the air handling unit to bear latent heat load and sensible heat load. The remaining refrigerated water cooling capacity after primary use provides higher temperature and lower-grade cooling capacity for the fresh air unit through the fifth heat exchanger to bear the fresh air load.

The specific steps of heating mode are as follows:

When the intensity of solar radiation is high, it operates in the mode of low-temperature heat energy preparation, supply, storage and release, and high-temperature heat energy preparation and supply. The cold energy/thermal energy storage tank is used as a high-temperature heat source, and the outdoor air is used as a low-temperature heat source. Solar PV/T heat collection The inverter converts solar energy into electric energy and heat energy. The prepared electric energy is used to drive the compressor and circulation pump. Part of the prepared heat energy is used to directly preheat the fresh air, and the other part of the prepared heat energy is used to heat the cold energy/heat energy storage tank The phase change material is converted into latent heat storage, and the second heat exchanger of the heat pump cycle with a low compression ratio of the staged compression unit acts as a high temperature evaporator to absorb the latent heat stored by the phase change material from the energy storage/release unit. At the same time, the staged compression unit’s The fourth heat exchanger of the heat pump cycle with high compression ratio acts as a low-temperature evaporator to absorb air heat energy from the outdoor low-temperature environment;

When the solar radiation intensity is weak, the low-temperature thermal energy release and supply, high-temperature thermal energy preparation and supply modes operate, the low compression ratio heat pump cycle stops working, the outdoor air is used as a low-temperature heat source, and the solar PV/T collector converts solar energy into Electric energy and heat energy, the prepared electric energy is used to drive the compressor and circulation pump, all the heat energy prepared is used to directly preheat the fresh air, and the fourth heat exchanger of the high compression ratio heat pump cycle of the staged pressure unit is used as a low-temperature evaporation The device absorbs air heat energy from the outdoor low-temperature environment, and produces high-grade high-temperature heat energy through the single-stage compression process of the compressor for heating air-conditioning air supply;

When there is no solar radiation, it operates in the mode of releasing and supplying low-temperature heat energy and preparing and supplying high-temperature heat energy. The cold energy/thermal energy storage tank is used as a high-temperature heat source, and the outdoor air is used as a low-temperature heat source. The solar PV/T collector stops working. The prepared electric energy is used to drive the compressor and the circulation pump, and the heat energy stored in the phase change material of the cold energy/heat energy storage tank is released. Part of the heat energy is used to directly preheat the fresh air, and the other part of the heat energy is used as a high-temperature heat source. The second heat exchanger of the low compression ratio heat pump cycle acts as a high temperature evaporator to absorb the latent heat stored in the phase change material from the energy storage/release unit, while the fourth heat exchanger of the low compression ratio heat pump cycle of the staged compression unit acts as The low-temperature evaporator absorbs air heat energy from the outdoor low-temperature environment, and the heat absorbed by the low-compression ratio heat pump cycle and the high-compression ratio heat pump cycle from high and low-temperature heat sources are produced through the cascade compression process of the compressor. High-temperature heat energy is used to heat air-conditioning air supply;

When there is no solar radiation and the phase change material of the cold energy/thermal energy storage tank has no latent heat storage, it operates in the high temperature heat energy preparation and supply mode, the outdoor air is used as a low temperature heat source, the heat pump cycle with low compression ratio stops working, and the heat pump with high compression ratio The third heat exchanger of the cycle is used as a condenser to prepare high-temperature, high-quality hot water to supply the air-handling unit to undertake the heating load of the air conditioner. After the air-handling unit is used once, the remaining hot water heat energy passes through the fifth heat exchanger. Provide lower temperature and lower grade heat energy for the fresh air unit to preheat the fresh air.

The present invention at least includes the following beneficial effects:

First, the present invention, through improvement, includes three major parts: a graded compression unit, an energy storage/release unit, and a solar photovoltaic photothermal unit. According to different needs, it can realize the cooperative operation of the three, and at the same time realize the independent operation of a single system. Operation work; the energy storage/release unit realizes the energy transfer and energy storage between the hierarchical compression unit and the solar photovoltaic photothermal unit; the energy storage/release unit stores thermal energy, and one is used to bear the fresh air preheating load in the heating mode , can also provide the heat at a higher temperature required by the compression heating cycle of the low pressure ratio, and realize the cascade compression heating cycle process of the compressor under the double evaporation temperature, through the cascade utilization of the low temperature heat energy of the outdoor environment and the low temperature heat energy produced by the solar energy , to prepare high-temperature and high-grade thermal energy, realize the improvement of low-temperature thermal energy, improve the heating efficiency of the compression heat pump cycle and the utilization rate of solar energy, and overcome the intermittent problem of traditional solar heating. On the one hand, the solar photovoltaic photothermal unit can provide the fresh air unit Part of the heat is supplied, and part of the heat energy can also be stored in the cold energy/heat energy storage tank. The hierarchical compression unit can realize both heating and cooling. The invention can effectively utilize solar energy, has the advantages of high reliability and remarkable energy-saving effect, and can be used as a cold and heat source for an air conditioner with multiple functions, especially suitable as a cold and heat source for an air conditioner system with independent temperature and humidity control.

Second, the present invention optimizes the refrigeration and heating method in combination with the above-mentioned specific structure. Through the organic combination with the entire system device, it can perform joint operation or Independent operation realizes the cascade preparation and utilization of cold/heat; under cooling conditions, when the power of the staged compression unit is low at night, it operates in a cascade compression refrigeration cycle, which not only meets the cooling demand of building air conditioners at night, but also stores cold energy in the The cold energy/thermal energy storage tank is used to eliminate the sensible heat and cooling load of the building. During the daytime, the graded compression unit only needs to produce low-temperature cold water to bear the latent heat load of the building, thereby providing different grades of cooling capacity for the building’s air-conditioning temperature and humidity independent control air-conditioning system to achieve The latent heat load and the sensible heat load of the building are treated separately to reduce the power consumption of the air conditioning system during the peak period of the daytime power, which helps to shift the peak power and reduce operating costs; under heating conditions, when the solar energy is sufficient Low-grade solar heat source, solar photovoltaic photothermal unit can also provide part of the heat required by the fresh air unit and use other heat energy to heat the phase change material of the cold energy/thermal energy storage tank and convert it into latent heat storage; when there is no solar energy and there is During phase change energy storage, the thermal energy stored in the cold energy/thermal energy storage tank is used to bear the fresh air preheating load in the heating mode, and can also provide the heat at a higher temperature required by the compression heating cycle of the low pressure ratio, for supply The thermal realization of the compressor cascade compression heating cycle process under double evaporation temperature can effectively improve the heating efficiency and solar energy utilization rate of the compression heat pump cycle, and overcome the intermittent problem of traditional solar heating.

Description of drawings

Fig. 1 is the structural diagram of the hierarchical compression refrigeration/heating system of the present invention (embodiment 1);

Fig. 2 is a structural diagram of the hierarchical compression refrigeration/heating system of the present invention (embodiment 2);

Fig. 3 is a structural diagram of the hierarchical compression refrigeration/heating system of the present invention (embodiment 3);

Marks in the figure: 1, compressor, 1a, first compressor, 1b, second compressor, 2, four-way reversing valve, 3, third heat exchanger, 4, second heat exchanger, 5, gas Liquid separator, 6. Fourth heat exchanger, 7. Cold energy/heat energy storage tank, 8. First heat exchanger, 9. Circulation pump I, 10. Solar PV/T heat collector, 11. Fresh air unit, 12. Air handling unit, 13. Circulation pump II, 14. Fifth heat exchanger, 101. First throttling part, 102. Second throttling part, 103. Third throttling part, 104. Fourth throttling part Parts, 201, first control valve, 202, second control valve, 203, third control valve, 204, fourth control valve, 205, fifth control valve, 206, sixth control valve, 207, seventh control valve .

Detailed ways

The present invention will be specifically described through exemplary embodiments below. It should be understood, however, that elements, structures and characteristics of one embodiment may be beneficially incorporated in other embodiments without further recitation.

Example 1

As shown in Figure 1, this solution provides a hierarchical compression refrigeration/heating system for temperature and humidity independent air conditioning, which is composed of three parts: solar photovoltaic photothermal unit, hierarchical compression unit and energy storage/release unit. Energy storage/ The release unit includes a cold/thermal energy storage tank 7, a first heat exchanger 8 and a second heat exchanger 4, wherein the first heat exchanger 8 and the second heat exchanger 4 are placed in the cold/thermal energy storage tank 7, The cold energy/heat energy storage tank 7 is used to fill the phase change energy storage filler, wherein the first heat exchanger 8 and the second heat exchanger 4 are arranged in the cold energy/heat energy storage tank 7 and submerged at a phase change temperature of 10°C-30°C. Among the phase-change energy storage fillers at ℃; the phase-change materials used in the cold energy/heat energy storage tank 7 are materials with relatively stable properties such as fatty acids, polyols, paraffin wax, graphite or expanded graphite. The first heat exchanger 8 and the second heat exchanger 4 are coil heat exchangers or finned tube heat exchangers. The inlet and outlet ends of the first heat exchanger 8 are respectively connected with the solar photovoltaic photothermal unit, and the inlet and outlet ends of the second heat exchanger 4 are respectively connected with the hierarchical compression unit, and the energy storage/release unit is used in different situations Next, heat or cold energy storage and/or heat exchange are carried out.

It should be pointed out that: the arrows in Figure 1-3 show the positive direction of fluid flow, the hollow arrows show the positive direction of fluid flow in cooling mode, and the solid arrows show the positive direction of fluid flow in heating mode.

In this solution, when the hierarchical compression unit operates in the heating mode, the solar photovoltaic photothermal unit can provide part of the heat required by the fresh air unit 11 on the one hand, and can also store part of the heat energy in the cold energy/heat energy storage tank 7, The cold energy/thermal energy storage tank 7 can be used to store thermal energy. One is to bear the fresh air preheating load in the heating mode when the solar energy is insufficient or without solar energy, and it can also provide the heat at a higher temperature required by the compression heating cycle of the low pressure ratio. , realizing the cascade compression heating cycle process of the compressor under the double evaporation temperature, and improving the heating efficiency and solar energy utilization rate of the compression heat pump cycle.

In this solution, the solar photovoltaic photothermal unit includes a solar PV/T heat collector 10, a circulation pump I9, a fresh air unit 11, a first control valve 201, a second control valve 202, and a seventh control valve 207. The solar photovoltaic photothermal unit The solar PV/T heat collector 10, the fresh air unit 11, the first heat exchanger 8 and the circulating pump I9 are sequentially connected in series to form a closed cycle; the solar PV/T heat collector 10 is used to absorb solar energy and convert it into electrical energy and heat energy , provide thermal energy to the fresh air unit 11 for heating the fresh air, and also provide thermal energy for heating the phase change material of the energy storage/release unit to realize thermal energy storage; the inlet and outlet of the solar PV/T heat collector 10 are respectively provided with first control valves 201 And the seventh control valve 207, the inlet and outlet of the solar PV/T heat collector 10 are also provided with bypass pipes, and the second control valve 202 is arranged on the bypass pipes.

In this embodiment, the circulation pump I9 is set on the first water circulation passage and is located at the outlet end of the first heat exchanger 8. The outlet of the circulation pump I9 is divided into branch one and branch two, and the branch one is controlled by the first The valve 201 is connected with the inlet of the solar PV/T heat collector 10, the outlet of the solar PV/T heat collector 10 is connected with the seventh control valve 207, and the second control valve 202 is arranged on the branch road two, and the branch road two is connected with the branch road The outlet of Road 1 is connected to the inlet of the heat exchange pipe of the fresh air unit 11. The outlet of the heat exchange pipe is divided into two branches, one of which is connected to the inlet of the first heat exchanger 8 through the third control valve 203, and the other One branch is connected to the inlet of a heat exchange channel of the fifth heat exchanger 14 through the fourth control valve 204 , and the outlet of a heat exchange channel of the fifth heat exchanger 14 is connected to the inlet of the first heat exchanger 8 . In this solution, the fresh air unit 11 is a plate heat exchanger.

In this solution, the staged compression unit includes a first compressor 1a, a second compressor 1b, a four-way reversing valve 2, a third heat exchanger 3, a gas-liquid separator 5, a fourth heat exchanger 6, a first section The flow part 101, the second throttling part 102, the third throttling part 103, the fourth throttling part 104, the third heat exchanger 3 is a shell-and-tube heat exchanger, and the fourth heat exchanger 6 is a plate-fin heat exchanger. Heater or finned tube heat exchanger. The first, second, third and fourth throttling components are thermal expansion valves or electronic expansion valves. Wherein the first compressor 1a has a medium-pressure suction port and a high-pressure discharge port, and the second compressor 1b has a low-pressure suction port and a high-pressure discharge port.

In this embodiment, the four-way reversing valve 2 has a first port a, a second port b, a third port c, and a fourth port d, and the first, second, third, and fourth ports of the four-way reversing valve 2 correspond to those in the figure The positions indicated by 1, 2, 3, and 4 of the four-way reversing valve 2, wherein the first port a is the high-pressure gas inlet, the fourth port d is the low-pressure gas outlet, and the second port b is connected to the fourth heat exchanger 6 One port is connected, the third port c is connected with one port of the refrigerant channel of the third heat exchanger 3, the high-pressure exhaust ports of the first compressor 1a and the second compressor 1b are connected with the first port of the four-way reversing valve 2 The port a is connected, and the low-pressure suction port of the second compressor 1b is connected with the fourth port d of the four-way reversing valve 2. The four-way reversing valve 2 has a valve body and is accommodated in the valve body and is in the first position and The slider that moves between the second positions, when the slider is in the first position, the first port a communicates with the second port b, and the third port c communicates with the fourth port d; when the slider is in the second position, the first Port a communicates with the third port c, and the second port b communicates with the fourth port d.

In this embodiment, the other port of the refrigerant channel of the fourth heat exchanger 6 is divided into two branches, one of which is connected to the outlet of the second throttling member 102, and the other branch is connected to the outlet of the third section. The inlet of the flow member 103 is connected, the outlet of the third throttling member 103 is connected with the inlet of the second heat exchanger 4, the outlet of the second heat exchanger 4 is connected with the gas-liquid separator 5, and the gas in the gas-liquid separator 5 is discharged The pipeline is provided with a U-shaped bend, and at least one small oil return hole is arranged at the lowest point of the U-shaped bend.

In this scheme, the gas discharge pipeline of the gas-liquid separator 5 is connected with the suction port of the first compressor 1a, and the liquid discharge pipeline of the gas-liquid separator 5 is divided into two branches, one of which is connected with the second The inlet of the throttling part 102 is connected, and the other branch is connected with the inlet of the fourth throttling part 104, and the outlet of the fourth throttling part 104 is connected to the inlet of the first throttling part 101 and the refrigerant channel of the third heat exchanger 3 on the connecting line between one of the ports.

In this embodiment, the water channel of the solar photovoltaic photothermal unit, the water channel of the fresh air unit 11 and the circulation pump I9 constitute the first water circulation channel, and the first water circulation channel is also connected to the first heat exchange channel of the fifth heat exchanger 14, The water channel of the air handling unit 12, the water channel of the third heat exchanger 3 and the circulation pump II13 constitute the second water circulation channel, and the second water circulation channel is connected with the second heat exchange channel of the fifth heat exchanger 14, through the fifth heat exchanger 14 The heater 14 can realize heat exchange between the water systems of the first water circulation path and the second water circulation path.

The outlet of the water channel of the fresh air unit 11 is divided into two branches, one of which is connected to the inlet of the first heat exchanger 8 through the third control valve 203, and the other branch is connected to the fifth heat exchanger through the fourth control valve 204. The inlet of the first heat exchange channel of 14 is connected, and the outlet of the first heat exchange channel of the fifth heat exchanger 14 is connected with the inlet of the first heat exchanger 8; the water channel outlet of the air handling unit 12 is divided into two branches One branch is connected with the inlet of the third heat exchanger 3 through the fifth control valve 205, and the other branch is connected with the inlet of the second heat exchange channel of the fifth heat exchanger 14 through the sixth control valve 206, The outlet of the second heat exchange channel of the fifth heat exchanger 14 is connected with the inlet of the third heat exchanger 3 , and the outlet of the third heat exchanger 3 is connected with the water pipe inlet of the air handling unit 12 through the circulation pump II13 .

Example 2

The difference between this embodiment and Embodiment 1 is that the staged compression unit includes a two-stage compressor 1, a four-way reversing valve 2, a third heat exchanger 3, a gas-liquid separator 5, a fourth heat exchanger 6, a first section The flow part 101, the second throttling part 102, the third throttling part 103, the fourth throttling part 104, the third heat exchanger 3 is a shell-and-tube heat exchanger, and the fourth heat exchanger 6 is a plate-fin heat exchanger. Heater or finned tube heat exchanger. The first, second, third and fourth throttling components are thermal expansion valves or electronic expansion valves. Wherein the two-stage compressor 1 has a low-pressure suction port, a medium-pressure suction port and a high-pressure discharge port.

The four-way reversing valve 2 has a first port a, a second port b, a third port c and a fourth port d, and the first, second, third and fourth ports of the four-way reversing valve 2 correspond to the four-way reversing in the figure. To the positions indicated by 1, 2, 3, and 4 of the valve 2, the first port a is the high-pressure gas inlet, the fourth port d is the low-pressure gas outlet, and the second port b is connected to a port of the fourth heat exchanger 6, The third port c is connected to one port of the refrigerant channel of the third heat exchanger 3, the high-pressure exhaust port of the two-stage compressor 1 is connected to the first port a of the four-way reversing valve 2, and the port of the two-stage compressor 1 The low-pressure suction port is connected to the fourth port d of the four-way reversing valve 2, the medium-pressure suction port of the two-stage compressor 1 is connected to the top gas outlet of the gas-liquid separator 5, and the four-way reversing valve 2 has a valve body and a slider accommodated in the valve body and moving between the first position and the second position in the valve body, when the slider is in the first position, the first port a communicates with the second port b, and the third port c communicates with the fourth port d communicates; when the slider is in the second position, the first port a communicates with the third port c, and the second port b communicates with the fourth port d.

Example 3

The difference between this embodiment and Embodiment 1 is that the staged compression unit includes a first compressor 1a, a second compressor 1b, a four-way reversing valve 2, a third heat exchanger 3, a gas-liquid separator 5 and a fourth reversing valve. The heat exchanger 6, the first throttling part 101, the second throttling part 102, the third throttling part 103, the fourth throttling part 104, the third heat exchanger 3 is a shell-and-tube heat exchanger, and the fourth heat exchanging Device 6 is a plate-fin heat exchanger or a fin-tube heat exchanger. The first, second, third and fourth throttling components are thermal expansion valves or electronic expansion valves. Wherein the first compressor 1a has a medium-pressure suction port and a high-pressure discharge port, and the second compressor 1b has a low-pressure suction port and a medium-pressure discharge port.

The four-way reversing valve 2 has a first port a, a second port b, a third port c and a fourth port d, and the first, second, third and fourth ports of the four-way reversing valve 2 correspond to the four-way reversing in the figure. To the positions indicated by 1, 2, 3, and 4 of the valve 2, the first port a is the high-pressure gas inlet, the fourth port d is the low-pressure gas outlet, and the second port b is connected to a port of the fourth heat exchanger 6, The third port c is connected to one port of the refrigerant channel of the third heat exchanger 3, the high-pressure exhaust port of the first compressor 1a is connected to the first port a of the four-way reversing valve 2, and the first compressor 1a The air inlet is respectively connected to the exhaust port of the second compressor 1b and the top gas outlet of the gas-liquid separator 5, and the low-pressure suction port of the second compressor 1b is connected to the fourth port d of the four-way reversing valve 2, The four-way reversing valve 2 has a valve body and a slider housed in the valve body and moves between the first position and the second position in the valve body. When the slider is in the first position, the first port a communicates with the second port b , the third port c communicates with the fourth port d; when the slider is in the second position, the first port a communicates with the third port c, and the second port b communicates with the fourth port d.

This scheme also provides a circulation method for a graded compression refrigeration/heating system for temperature and humidity independent air conditioners. Under joint operation or independent operation; details are as follows:

1. Refrigeration method under refrigeration conditions:

The first control valve 201 and the seventh control valve are closed 207, the second control valve is opened 202; the third control valve 203 and the fifth control valve 205 are opened simultaneously, the fourth control valve 204 and the sixth control valve 206 are closed simultaneously (or The third control valve 203 and the fifth control valve 205 are closed at the same time, and the fourth control valve 204 and the sixth control valve 206 are opened at the same time).

In Embodiment 1, the first compressor 1a, the four-way reversing valve 2, the fourth heat exchanger 6, the third throttling member 103, the second heat exchanger 4, and the gas-liquid separator 5 are sequentially connected in series. Refrigeration cycle with low compression ratio; composed of the second compressor 1b, the four-way reversing valve 2, the fourth heat exchanger 6, the third throttling component 103, the second heat exchanger 4, the gas-liquid separator 5, the fourth The throttling component 104 and the third heat exchanger 3 are sequentially connected in series to form a refrigeration cycle with a high compression ratio, and the cascade compression process of the compressor is realized by the refrigeration cycle with a low compression ratio and the refrigeration cycle with a high compression ratio;

In Embodiment 2, it consists of a two-stage compressor 1, a four-way reversing valve 2, a fourth heat exchanger 6, a third throttling member 103, a second heat exchanger 4, and a gas-liquid separator 5 connected in series. Refrigeration cycle with low compression ratio; consists of two-stage compressor 1, four-way reversing valve 2, fourth heat exchanger 6, third throttling component 103, second heat exchanger 4, gas-liquid separator 5, fourth The throttling component 104 and the third heat exchanger 3 are sequentially connected in series to form a refrigeration cycle with a high compression ratio, and realize the compressor cascade compression process.

In Embodiment 3, the first compressor 1a, the four-way reversing valve 2, the fourth heat exchanger 6, the third throttling member 103, the second heat exchanger 4, and the gas-liquid separator 5 are sequentially connected in series. Refrigeration cycle with low compression ratio; composed of the second compressor 1b, the first compressor 1a, the four-way reversing valve 2, the fourth heat exchanger 6, the third throttling component 103, the second heat exchanger 4, the gas-liquid The separator 5, the fourth throttling part 104, and the third heat exchanger 3 are sequentially connected in series to form a high compression ratio refrigeration cycle, and the compressor cascade compression process is realized by the low compression ratio refrigeration cycle and the high compression ratio refrigeration cycle.

Solar photovoltaic photothermal unit (solar PV/T collector only produces electric energy but not thermal energy), hierarchical compression unit and air-conditioning energy storage/release unit work together; it has low-temperature potential cooling capacity preparation and supply, high-temperature potential cooling capacity preparation and storage and Release supply, low-temperature cooling capacity preparation and supply, high-temperature cooling capacity preparation and storage, low-temperature cooling capacity preparation and supply, high-temperature cooling capacity release supply, and low-temperature cooling capacity preparation and supply. There are four operating modes:

When operating in the mode of preparation and supply of low-temperature cooling capacity, storage and release of high-temperature cooling capacity, such as in the case of low power at night, the staged compression unit supplies cooling capacity to the cold energy/thermal energy storage tank 7 and the air handling unit 12 at the same time , the cold/thermal energy storage tank 7 provides the fresh air unit 11 to deal with the low-grade cooling capacity of the fresh air load, and the cold/thermal energy storage tank 7 is respectively provided by the double-temperature evaporation temperature of the second heat exchanger 4 and the third heat exchanger 3 The higher temperature cold capacity required by the cold storage process of the phase change material and the lower temperature cold capacity required by the air handling unit 12 to handle the humidity load of the humid air can provide high and low grade cold for the temperature and humidity independent control air conditioning system. To achieve the purpose of cascaded preparation and utilization of cooling capacity required by building latent heat load and sensible heat load; the third heat exchanger 3 of the refrigeration cycle with high compression ratio is used as a low-temperature evaporator to prepare lower-temperature, higher-grade cooling capacity The supply air handling unit 12 bears latent heat load and sensible heat load, and the second heat exchanger 4 of the refrigeration cycle with low compression ratio is used as a high-temperature evaporator to prepare higher-temperature, lower-grade cold energy, which is stored in cold energy/heat energy The storage tank 7 is also supplied to the fresh air unit 11 to bear the fresh air load; the solar photovoltaic photothermal unit, the hierarchical compression unit and the air conditioning energy storage/release unit work together to realize the cascade preparation and utilization of cooling capacity required by the air conditioning system with independent temperature and humidity control.

When operating in the low-temperature potential cooling capacity preparation supply and high-temperature potential cooling capacity preparation and storage mode, such as during the peak power during the day, the electric energy prepared by the solar PV/T heat collector 10 of the solar photovoltaic photothermal unit is used to drive the first The compressor 1a, the second compressor 1b, the two-stage compressor 1, the circulation pump I9 and the circulation pump II13 work, and the third heat exchanger 3 of the refrigeration cycle with high compression ratio is used as a low-temperature evaporator to prepare lower temperature and higher grade The chilled water is supplied to the air handling unit 12 to bear the latent heat load and the sensible heat load. The cooling capacity of the chilled water once used by the air handling unit 12 provides higher temperature and lower grade cooling for the fresh air unit 11 through the fifth heat exchanger 14. The amount is used to bear the load of fresh air; the second heat exchanger 4 of the refrigeration cycle with low compression ratio is used as a high-temperature evaporator to prepare higher temperature and lower-grade cold energy and store it completely in the cold energy/thermal energy storage tank 7; solar photovoltaic The photothermal unit, the graded compression unit and the air conditioning energy storage/release unit work together to realize the cascade utilization of high-grade cooling capacity and the cascade preparation of high-grade and low-grade cooling capacity required by the air-conditioning system with independent temperature and humidity control.

When operating in the low-temperature potential cooling capacity preparation supply mode and high-temperature potential cooling capacity release supply mode, such as in the case of peak power during the day, the electric energy prepared by the solar PV/T heat collector 10 of the solar photovoltaic photothermal unit is used to drive the embodiment The second compressor 1b in 1 or the two-stage compressor 1 in embodiment 2 or the first compressor 1a and the second compressor 1b in embodiment 3, the circulation pump I9 and the circulation pump II13 work, and the low compression ratio The refrigeration cycle stops working, and only the third heat exchanger 3 of the refrigeration cycle with high compression ratio is used as a low-temperature evaporator to prepare lower-temperature, higher-grade chilled water and supply it to the air handling unit 12 to bear latent heat load and sensible heat load; cold energy/heat energy The higher-temperature cold energy stored in the storage tank 7 is used to bear the fresh air load; the solar photovoltaic photothermal unit, the hierarchical compression unit and the air-conditioning energy storage/release unit work together to realize the preparation of the low-temperature cold energy required by the air-conditioning system with independent temperature and humidity control , Cascade utilization of high and low grade cold capacity.

When the supply mode is prepared by low-temperature potential cooling capacity, for example, when the cold energy/thermal energy storage tank 7 does not store cold capacity, the electric energy prepared by the solar PV/T heat collector 10 of the solar photovoltaic photothermal unit is used to drive The second compressor 1b in embodiment 1 or the two-stage compressor 1 in embodiment 2 or the first compressor 1a and the second compressor 1b in embodiment 3, circulation pump I9 and circulation pump II13 work, low compression The refrigerating cycle with a higher compression ratio stops working, and the third heat exchanger 3 of the refrigerating cycle with a high compression ratio is used as a low-temperature evaporator to prepare lower-temperature, higher-grade chilled water for supply to the air-handling unit 12 to bear latent heat load and sensible heat load. The remaining chilled water cooling capacity after the unit 12 is used once passes through the fifth heat exchanger 14 to provide higher temperature and lower-grade cooling capacity for the fresh air unit 11 to bear the fresh air load; the solar photovoltaic photothermal unit and the hierarchical compression unit work together Realize the preparation and cascade utilization of high-grade cooling capacity required by the air-conditioning system with independent temperature and humidity control.

2. Heating method under heating conditions:

The first control valve 201 and the seventh control valve open 207, the second control valve 202 closes; the third control valve 203 and the fifth control valve 205 open simultaneously, the fourth control valve 204 and the sixth control valve 206 close simultaneously (or The third control valve 203 and the fifth control valve 205 are closed at the same time, and the fourth control valve 204 and the sixth control valve 206 are opened at the same time).

In Embodiment 1, the first compressor 1a, the four-way reversing valve 2, the third heat exchanger 3, the first throttle member 101, the second heat exchanger 4, and the gas-liquid separator 5 are sequentially connected in series. A heat pump cycle with a low compression ratio; composed of the second compressor 1b, the four-way reversing valve 2, the third heat exchanger 3, the first throttling component 101, the second heat exchanger 4, the gas-liquid separator 5, the second The throttling component 102 and the fourth heat exchanger 6 are sequentially connected in series to form a high compression ratio heat pump cycle, and the compressor cascade compression process is realized by the low compression ratio heat pump cycle and the high compression ratio heat pump cycle;

In Embodiment 2, it consists of a two-stage compressor 1, a four-way reversing valve 2, a third heat exchanger 3, a first throttling member 101, a second heat exchanger 4, and a gas-liquid separator 5 connected in series. A heat pump cycle with a low compression ratio; consisting of a two-stage compressor 1, a four-way reversing valve 2, a third heat exchanger 3, a first throttling component 101, a second heat exchanger 4, a gas-liquid separator 5, a second The throttling component 102 and the fourth heat exchanger 6 are sequentially connected in series to form a high compression ratio heat pump cycle, and the compressor cascade compression process is realized by the low compression ratio heat pump cycle and the high compression ratio heat pump cycle.

In Embodiment 3, the first compressor 1a, the four-way reversing valve 2, the third heat exchanger 3, the first throttling member 101, the second heat exchanger 4, and the gas-liquid separator 5 are sequentially connected in series. Heat pump cycle with low compression ratio; composed of the second compressor 1b, the first compressor 1a, the four-way reversing valve 2, the third heat exchanger 3, the first throttling component 101, the second heat exchanger 4, the gas-liquid The separator 5, the second throttling component 102, and the fourth heat exchanger 6 are sequentially connected in series to form a high compression ratio heat pump cycle, and the compressor cascade compression process is realized by the low compression ratio heat pump cycle and the high compression ratio heat pump cycle.

Solar photovoltaic photothermal unit, hierarchical compression unit and air-conditioning energy storage/release unit work together; with low-temperature thermal energy preparation, supply, storage and release, high-temperature thermal energy preparation and supply, low-temperature thermal energy preparation and supply, high-temperature thermal energy preparation and Supply, low-temperature thermal energy release and supply, high-temperature thermal energy preparation and supply, high-temperature thermal energy preparation and supply, a total of four operating modes:

When the solar radiation intensity is high, it operates in the mode of low-temperature heat energy preparation, supply, storage and release, and high-temperature heat energy preparation and supply mode. The cold energy/thermal energy storage tank 7 is used as a high-temperature heat source, and the outdoor air is used as a low-temperature heat source. The solar photovoltaic photothermal unit The solar PV/T heat collector 10 converts solar energy into electric energy and thermal energy, and the prepared electric energy is used to drive the first compressor 1a in the embodiment 1 and the embodiment 3, the second compressor 1b or the compressor in the embodiment 2 Two-stage compressor 1, circulating pump I9 and circulating pump II13 work, part of the heat energy prepared is used to directly preheat the fresh air, and another part of the heat energy prepared is used to heat the phase change material of the cold energy/heat energy storage tank 7 and convert it into latent heat Storage, the second heat exchanger 4 of the low compression ratio heat pump cycle of the staged compression unit acts as a high temperature evaporator to absorb the latent heat stored by the phase change material from the air conditioning energy storage/release unit, meanwhile, the high compression ratio heat pump of the staged compression unit The fourth heat exchanger 6 of the cycle acts as a low-temperature evaporator to absorb air heat energy from the outdoor low-temperature environment, that is, the heat absorbed by the heat pump cycle with a low compression ratio and the heat pump cycle with a high compression ratio from high and low temperature heat sources respectively, through compression The cascade compression process of the machine produces high-grade high-temperature heat energy for heating the air supply of the air conditioner, and the joint work of the solar photovoltaic photothermal unit, the hierarchical compression unit and the energy storage/release unit of the air conditioner realizes the cascade preparation and utilization of heat energy for air conditioning heating, and low-temperature heat energy. Gradual extraction and graded improvement of thermal energy grade.

When the solar radiation intensity is weak, the low-temperature thermal energy release and supply, high-temperature thermal energy preparation and supply modes operate, the heat pump cycle with low compression ratio stops working, the outdoor air is used as a low-temperature heat source, and the solar PV/T collector of the solar photovoltaic photothermal unit Heater 10 converts solar energy into electric energy and thermal energy, and the prepared electric energy is used to drive the second compressor 1b in embodiment 1 or the two-stage compressor 1 in embodiment 2 or the first compressor 1a in embodiment 3 Working with the second compressor 1b, circulation pump I9 and circulation pump II13, all the heat energy prepared is used to directly preheat the fresh air, and the fourth heat exchanger 6 of the heat pump cycle with low compression ratio of the staged compression unit is used as a low-temperature evaporator Absorb air heat energy from the outdoor low-temperature environment, and produce high-grade high-temperature heat energy through the single-stage compression process of the compressor to heat the air supply of the air conditioner. The solar photovoltaic photothermal unit, the hierarchical compression unit and the air conditioner energy storage/release unit work together to realize the air conditioner Cascade preparation and utilization of thermal energy for heating, and improvement of low-temperature thermal energy grade.

When there is no solar radiation, it operates in the mode of releasing and supplying low-temperature heat energy and preparing and supplying high-temperature heat energy. The cold energy/thermal energy storage tank 7 is used as a high-temperature heat source, and the outdoor air is used as a low-temperature heat source. The solar PV/T of the solar photovoltaic photothermal unit The heat collector 10 stops working, and the prepared electric energy is used to drive the first compressor 1a in the embodiment 1 and the embodiment 3, the second compressor 1b or the double-stage compressor 1, the circulating pump 19 and the second compressor 1b in the embodiment 2. The circulating pump II13 works, and the thermal energy stored in the phase change material of the cold/thermal energy storage tank 7 is released. A part of the thermal energy is used to directly preheat the fresh air, and the other part of the thermal energy is used as a high-temperature heat source. The low compression ratio heat pump cycle of the staged compression unit The second heat exchanger 4 acts as a high-temperature evaporator to absorb the latent heat stored in the phase change material from the air-conditioning energy storage/release unit, and at the same time, the fourth heat exchanger 6 of the low compression ratio heat pump cycle of the staged compression unit acts as a low-temperature evaporator Absorb air heat energy from outdoor low temperature environment, heat absorbed by low compression ratio heat pump cycle and high compression ratio heat pump cycle from high and low temperature heat sources, and produce high-grade high temperature heat energy through the cascade compression process of compressors for use Heating and air-conditioning air supply, solar photovoltaic photothermal unit, graded compression unit and air-conditioning energy storage/release unit work together to realize the cascade preparation and utilization of air-conditioning heating heat energy, the cascade extraction of low-temperature heat energy and the graded improvement of heat energy grade.

When there is no solar radiation and the phase change material of the cold energy/thermal energy storage tank has no latent heat storage, it operates in the high temperature heat energy preparation and supply mode, the outdoor air is used as a low temperature heat source, the heat pump cycle with low compression ratio stops working, and the heat pump with high compression ratio The third heat exchanger 3 of the cycle is used as a condenser to prepare high-temperature, high-quality hot water and supply it to the air-handling unit 12 to bear the heat supply load of the air conditioner. The heat exchanger 14 provides the fresh air unit 11 with lower-temperature, lower-grade heat energy for preheating the fresh air; the solar photovoltaic photothermal unit and the graded compression unit work together to realize the preparation and cascade utilization of heat energy for air conditioning and heating, and the extraction of low-temperature heat energy and The grade of low-temperature heat energy is improved.

The scheme works as follows:

1. Cooling mode

The solar photovoltaic photothermal unit only provides electric energy, the first control valve 201, the seventh control valve 207 are closed, the second control valve is opened 202; the third control valve 203, the fifth control valve 205 are opened simultaneously, the fourth control valve 204, the The six control valves 206 are closed at the same time (or the third control valve 203 and the fifth control valve 205 are closed at the same time, and the fourth control valve 204 and the sixth control valve 206 are opened at the same time);

In Example 1, the high-temperature and high-pressure gaseous refrigerant after being adiabatically compressed by the first compressor 1a and the second compressor 1b enters the fourth heat exchanger 6 through the four-way reversing valve 2 to perform isobaric heat release. It is a medium-temperature and high-pressure liquid refrigerant, which becomes a medium-temperature and medium-pressure liquid refrigerant after being adiabatically throttled by the third throttling part 103, and the medium-temperature and medium-pressure liquid refrigerant enters the second heat exchanger 4, and a part of the liquid refrigerant, etc. The latent heat of the phase-change material in the pressure-absorbing cold energy/heat energy storage tank 7 produces high-temperature, low-grade cooling capacity, and becomes a medium-temperature and medium-pressure gaseous refrigerant, which enters the gas-liquid together with the liquid refrigerant that does not absorb heat. In the separator 5, the medium-temperature and medium-pressure gaseous refrigerant enters the medium-pressure suction port of the first compressor 1a through the gas discharge pipeline in the gas-liquid separator 5 to complete the low-pressure ratio compression refrigeration cycle, and the gas-liquid separator 5 The medium-temperature and medium-pressure liquid refrigerant flows out from the liquid pipeline, becomes a low-temperature and low-pressure liquid refrigerant after being adiabatically throttled by the fourth throttling part 104, and enters the third heat exchanger 3 to absorb heat at equal pressure to obtain a low-temperature refrigerant. 1. The high-grade cooling capacity becomes a low-temperature and low-pressure gaseous refrigerant, which enters the low-pressure suction port of the second compressor 1b through the four-way reversing valve 2 to complete the high-pressure ratio compression refrigeration cycle.

In Example 2, the high-temperature and high-pressure gaseous refrigerant after being adiabatically compressed by the two-stage compressor 1 enters the fourth heat exchanger 6 through the four-way reversing valve 2 for isobaric heat release, and becomes medium-temperature and high-pressure liquid refrigeration After being adiabatically throttled by the third throttling part 103, it becomes a medium-temperature and medium-pressure liquid refrigerant, and the medium-temperature and medium-pressure liquid refrigerant enters the second heat exchanger 4, and a part of the liquid refrigerant absorbs cold energy/heat energy at equal pressure The latent heat of the phase-change material in the storage tank 7 produces high-temperature, low-grade cooling capacity, which becomes a medium-temperature and medium-pressure gaseous refrigerant, and enters the gas-liquid separator 5 together with the liquid refrigerant that does not absorb heat. The medium-pressure gaseous refrigerant enters the medium-pressure suction port of the two-stage compressor 1 through the gas discharge pipeline in the gas-liquid separator 5 to complete the low-pressure ratio compression refrigeration cycle, and the medium-temperature and medium-pressure liquid refrigeration in the gas-liquid separator 5 The refrigerant flows out from the liquid pipeline, becomes a low-temperature and low-pressure liquid refrigerant after being adiabatically throttled by the fourth throttling part 104, and enters the third heat exchanger 3 for isobaric heat absorption to produce low-temperature, high-grade cooling capacity. , becomes a low-temperature and low-pressure gaseous refrigerant, and enters the low-pressure suction port of the two-stage compressor 1 through the four-way reversing valve 2 to complete the high-pressure ratio compression refrigeration cycle.

In Example 3, the high-temperature and high-pressure gaseous refrigerant after being adiabatically compressed by the first compressor 1a enters the fourth heat exchanger 6 through the four-way reversing valve 2 for isobaric heat release, and becomes medium-temperature and high-pressure liquid refrigeration After being adiabatically throttled by the third throttling part 103, it becomes a medium-temperature and medium-pressure liquid refrigerant, and the medium-temperature and medium-pressure liquid refrigerant enters the second heat exchanger 4, and a part of the liquid refrigerant absorbs cold energy/heat energy at equal pressure The latent heat of the phase-change material in the storage tank 7 produces high-temperature, low-grade cooling capacity, which becomes a medium-temperature and medium-pressure gaseous refrigerant, and enters the gas-liquid separator 5 together with the liquid refrigerant that does not absorb heat. The medium-pressure gaseous refrigerant enters the medium-pressure suction port of the first compressor 1a through the gas discharge pipeline in the gas-liquid separator 5 to complete the low-pressure ratio compression refrigeration cycle, and the medium-temperature and medium-pressure liquid refrigeration in the gas-liquid separator 5 The refrigerant flows out from the liquid pipeline, becomes a low-temperature and low-pressure liquid refrigerant after being adiabatically throttled by the fourth throttling part 104, and enters the third heat exchanger 3 for isobaric heat absorption to produce low-temperature, high-grade cooling capacity. , becomes a low-temperature and low-pressure gaseous refrigerant, enters the low-pressure suction port of the second compressor 1b through the four-way reversing valve 2, and is adiabatically compressed into a medium-temperature and medium-pressure gaseous refrigerant, which is then combined with the gas-liquid separator 5 The medium-temperature and medium-pressure gaseous refrigerant that comes out enters the first compressor 1a together to complete the low-pressure ratio compression refrigeration cycle.

The phase change material in the cold energy/thermal energy storage tank 7 releases heat through the second heat exchanger 4 to store high-temperature and low-grade cold energy, and then releases the stored cold energy to solar photovoltaic through the first heat exchanger 8 Circulating water inside the photothermal unit.

When there is no cold energy stored in the cold energy/thermal energy storage tank 7 and the refrigeration cycle with a low compression ratio stops working, the chilled water from the air handling unit 12 enters the fifth heat exchanger 14 through the sixth control valve 206 to absorb heat , the chilled water after absorbing heat enters the third heat exchanger 3 for isobaric heat release, and the circulating water from the fresh air unit 11 enters the fifth heat exchanger 14 through the fourth control valve 204 for heat release, after heat release The circulating water continues to pre-cool the fresh air.

The circulating water in the solar photovoltaic photothermal unit releases heat in the first heat exchanger 8 and turns into cold water. After being pressurized by the circulating pump I9, it passes through the second control valve 202 and enters the fresh air unit 11 to pre-cool the fresh air and exchange heat. The final circulating water enters the first heat exchanger 8 through the third control valve 203 or the fourth control valve 204 to complete the cycle.

After the third heat exchanger 3 releases heat, the low-temperature chilled water is pressurized by the circulating pump II13, and then enters the air handling unit 12 to cool the air, and the chilled water after heat exchange passes through the fifth control valve 205 or the sixth control valve 206 Enter the third heat exchanger 3 to complete the cycle.

The cooling capacity of different evaporation temperatures is obtained through the second heat exchanger 4 and the third heat exchanger 3 respectively to meet the cooling capacity of the cold energy/thermal energy storage tank 7 during the cold storage process and the cooling demand of the air handling unit 12, thereby providing The air-conditioning temperature and humidity are independently controlled. The air-conditioning system provides cooling capacity of different grades and realizes separate processing of building latent heat load and sensible heat load.

2. Heating mode

The first control valve 201 and the seventh control valve 207 are opened, the second control valve 202 is closed; the third control valve 203 and the fifth control valve 205 are opened simultaneously, the fourth control valve 204 and the sixth control valve 206 are closed simultaneously (or The third control valve 203 and the fifth control valve 205 are closed at the same time, and the fourth control valve 204 and the sixth control valve 206 are opened at the same time).

In Example 1, the high-temperature and high-pressure gaseous refrigerant after undergoing adiabatic compression in the first compressor 1a and the second compressor 1b enters the third heat exchanger 3 through the four-way reversing valve 2 for isobaric exothermic refrigeration. Take high-temperature, high-grade heat energy, release heat, and turn it into a high-temperature and high-pressure liquid refrigerant, and then turn it into a medium-temperature and medium-pressure liquid refrigerant after being adiabatically throttled by the first throttling part 101, and a part of the medium-temperature and medium-pressure liquid refrigerant In the second heat exchanger 4, the heat energy stored in the cold energy/heat energy storage tank 7 is absorbed at equal pressure and becomes a medium-temperature and medium-pressure gaseous refrigerant and enters the gas-liquid separator 5, and the medium-temperature and medium-pressure gaseous refrigerant flows from the gas-liquid separator. 5 The gas discharge pipeline enters the first compressor 1a to complete the heat pump cycle with low compression ratio, and another part of the medium-temperature and medium-pressure liquid refrigerant enters the gas-liquid separator 5 from the second heat exchanger 4, and the medium-temperature and medium-pressure liquid refrigerant enters the gas-liquid separator 5 from the The liquid outlet of the gas-liquid separator 5 is adiabatically throttled by the second throttling part 102 to become a low-temperature and low-pressure liquid refrigerant, and the low-temperature and low-pressure liquid refrigerant enters the fourth heat exchanger 6 for isobaric heat absorption and becomes a low-temperature refrigerant. The low-pressure gaseous refrigerant enters the low-pressure suction port of the second compressor 1b through the four-way reversing valve 2 to complete the high-pressure ratio heat pump cycle. The second heat exchanger 4 is used as a high-temperature heat source, and the fourth heat exchanger 6 is used as a low-temperature heat source to realize the preparation and cascade utilization of heat energy for air-conditioning heating, the extraction of low-temperature heat energy, and the improvement of the grade of low-temperature heat energy.

In Example 2, the high-temperature and high-pressure gaseous refrigerant after undergoing adiabatic compression in the two-stage compressor 1 enters the third heat exchanger 3 through the four-way reversing valve 2 for isobaric heat release to produce high-temperature and high-grade The thermal energy becomes a high-temperature and high-pressure liquid refrigerant after heat release, and becomes a medium-temperature and medium-pressure liquid refrigerant after being adiabatically throttled by the first throttling part 101. A part of the medium-temperature and medium-pressure liquid refrigerant is in the second heat exchanger 4. The heat energy stored in the storage tank 7 for absorbing cold energy/heat energy at medium and equal pressure becomes medium-temperature and medium-pressure gaseous refrigerant and enters the gas-liquid separator 5, and the medium-temperature and medium-pressure gaseous refrigerant enters from the gas discharge pipeline of the gas-liquid separator 5 The medium-pressure suction port of the two-stage compressor 1 completes the heat pump cycle with a low compression ratio, and another part of medium-temperature and medium-pressure liquid refrigerant enters the gas-liquid separator 5 from the second heat exchanger 4, and the medium-temperature and medium-pressure liquid refrigerant enters the gas-liquid separator 5 from the The liquid outlet of the gas-liquid separator 5 is adiabatically throttled by the second throttling part 102 to become a low-temperature and low-pressure liquid refrigerant, and the low-temperature and low-pressure liquid refrigerant enters the fourth heat exchanger 6 for isobaric heat absorption and becomes a low-temperature refrigerant. The low-pressure gaseous refrigerant enters the low-pressure suction port of the two-stage compressor 1 through the four-way reversing valve 2 to complete the high-pressure ratio heat pump cycle. The second heat exchanger 4 is used as a high-temperature heat source, and the fourth heat exchanger 6 is used as a low-temperature heat source to realize the preparation and cascade utilization of heat energy for air-conditioning heating, the extraction of low-temperature heat energy, and the improvement of the grade of low-temperature heat energy.

In Example 3, the high-temperature and high-pressure gaseous refrigerant after undergoing adiabatic compression in the first compressor 1a enters the third heat exchanger 3 through the four-way reversing valve 2 for isobaric heat release to produce high-temperature and high-grade The thermal energy becomes a high-temperature and high-pressure liquid refrigerant after heat release, and becomes a medium-temperature and medium-pressure liquid refrigerant after being adiabatically throttled by the first throttling part 101. A part of the medium-temperature and medium-pressure liquid refrigerant is in the second heat exchanger 4. The heat energy stored in the storage tank 7 for absorbing cold energy/heat energy at medium and equal pressure becomes medium-temperature and medium-pressure gaseous refrigerant and enters the gas-liquid separator 5, and the medium-temperature and medium-pressure gaseous refrigerant enters from the gas discharge pipeline of the gas-liquid separator 5 The first compressor 1a completes the heat pump cycle with a low compression ratio, and another part of the medium-temperature and medium-pressure liquid refrigerant enters the gas-liquid separator 5 from the second heat exchanger 4, and the medium-temperature and medium-pressure liquid refrigerant flows from the gas-liquid separator 5. The liquid outlet is adiabatically throttled by the second throttling part 102 to become a low-temperature and low-pressure liquid refrigerant, and the low-temperature and low-pressure liquid refrigerant enters the fourth heat exchanger 6 to absorb heat at equal pressure, and becomes a low-temperature and low-pressure gaseous refrigerant. It enters the low-pressure suction port of the second compressor 1b through the four-way reversing valve 2, and is adiabatically compressed into a medium-temperature and medium-pressure gaseous refrigerant, and then enters together with the medium-temperature and medium-pressure gaseous refrigerant coming out of the gas-liquid separator 5 The low pressure ratio compression refrigeration cycle is completed in the first compressor 1a. The second heat exchanger 4 is used as a high-temperature heat source, and the fourth heat exchanger 6 is used as a low-temperature heat source to realize the preparation and cascade utilization of heat energy for air-conditioning heating, the extraction of low-temperature heat energy, and the improvement of the grade of low-temperature heat energy.

The solar PV/T heat collector 10 of the solar photovoltaic photothermal unit converts solar energy into electric energy and thermal energy, and the circulating water of the solar photovoltaic photothermal unit absorbs heat from the solar PV/T heat collector 10 and enters into the The fresh air unit 11 preheats the fresh air, and the circulating water after heat exchange enters the first heat exchanger 8 through the third control valve 203 or the fourth control valve 204 to continue to release heat, and the circulating water after heat release is pressurized by the circulating pump I9 After that, it enters the solar PV/T heat collector 10 through the first control valve 201 to reabsorb solar energy to complete the cycle.

When there is no solar radiation and the phase change material of the cold energy/thermal energy storage tank 7 has no latent heat storage, the hot water from the air handling unit 12 enters the fifth heat exchanger 14 through the sixth control valve 206 to release heat. The final hot water enters the third heat exchanger 3 to absorb heat at equal pressure, and the circulating water from the fresh air unit 11 enters the fifth heat exchanger 14 through the fourth control valve 204 to absorb heat, and the circulating water after absorbing heat Continue to preheat the fresh air.

The phase change material in the cold energy/thermal energy storage tank 7 absorbs the heat released by the circulating water of the solar photovoltaic photothermal unit from the first heat exchanger 8 to store heat, and then releases the stored heat to the graded through the second heat exchanger 4 Refrigerant for the compression unit.

After the third heat exchanger 3 absorbs heat, the high-temperature hot water is pressurized by the circulating pump II13, and then enters the air handling unit 12 to heat the air, and the hot water after heat exchange passes through the fifth control valve 205 or the sixth control valve 206 Enter the third heat exchanger 3 to complete the cycle.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any skilled person familiar with the profession , without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make some changes or be modified into equivalent embodiments with equivalent changes, but as long as it does not depart from the technical solution of the present invention, the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

Claims (10)

1. A hierarchical compression refrigeration/heating system for independent air conditioner of humiture, its characterized in that: the system comprises a solar photovoltaic photo-thermal unit, an energy storage/release unit and a hierarchical compression unit, wherein a water channel of the solar photovoltaic photo-thermal unit is connected with an inlet and an outlet of a water channel of a fresh air unit to form a first water circulation channel, the first water circulation channel is used for realizing heat exchange with the fresh air channel of the fresh air unit, a water channel of a third heat exchanger of the hierarchical compression unit and the water channel of an air treatment unit form a second water circulation channel, and the second water circulation channel is used for realizing heat exchange with the air channel of the air treatment unit;

The energy storage/release unit comprises a cold energy/heat energy storage tank, a first heat exchanger and a second heat exchanger, wherein the first heat exchanger and the second heat exchanger are positioned in the cold energy/heat energy storage tank, the first heat exchanger is connected with the solar photovoltaic photo-thermal unit, and the second heat exchanger is connected with the staged compression unit and is used for realizing energy transmission and energy storage of the solar photovoltaic photo-thermal unit and the staged compression unit;

the heat exchange device comprises a first water circulation channel, a second water circulation channel, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a first water circulation channel and a second water circulation channel, wherein the third heat exchanger comprises a first heat exchange channel and a second heat exchange channel which can realize heat exchange, two ends of the first heat exchange channel are connected with the first water circulation channel, two ends of the second heat exchange channel are connected with the second water circulation channel, and the first water circulation channel and the second water circulation channel can realize heat exchange through the third heat exchanger.

2. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 1, wherein: the water channel outlet of the fresh air handling unit is divided into two branches, wherein a first branch is connected with the first heat exchanger through a third control valve, the other branch is connected with the first heat exchange channel through a fourth control valve, the water channel outlet of the air handling unit is divided into two branches, one branch is connected with one end of the water channel of the third heat exchanger through a fifth control valve, and the other branch is connected with the second heat exchange channel through a sixth control valve.

3. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 2, wherein: the solar photovoltaic photo-thermal unit further comprises a solar heat collector, wherein a water channel inlet of the solar heat collector is connected with one branch of the outlet of the first heat exchanger through a first control valve, and the other branch of the outlet of the first heat exchanger is connected with a water channel inlet of the fresh air unit through a second control valve.

4. A staged compression refrigeration/heating system for a temperature and humidity independent air conditioner as recited in claim 3, wherein: the multi-stage compression heat pump unit further comprises a compressor, a four-way reversing valve and a gas-liquid separator, wherein the four-way reversing valve is provided with four ports, the first port is a high-pressure air inlet, the first port is connected with a high-pressure air outlet of the compressor, the fourth port is a low-pressure air outlet, the fourth port is connected with a low-pressure air inlet of the compressor, the third port is connected with one port of a refrigerant channel of the third heat exchanger, the other port of the refrigerant channel of the third heat exchanger is divided into two branches, the first branch is connected with an inlet of a first throttling part, an outlet of the first throttling part is connected with an inlet of a second heat exchanger, the second branch is connected with an outlet of a fourth throttling part, the inlet of the fourth throttling part is connected with a bottom liquid outlet of the gas-liquid separator, the outlet of the second heat exchanger is connected with an inlet of the gas-liquid separator, and the top gas outlet of the gas-liquid separator is connected with a medium-pressure air suction port of the compressor.

5. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 4, wherein: the four-way reversing valve is characterized by further comprising a fourth heat exchanger, wherein one port of a refrigerant channel of the fourth heat exchanger is connected with the second port of the four-way reversing valve, the other port of the refrigerant channel of the fourth heat exchanger is divided into two branches, one branch is connected with an inlet of the second heat exchanger through a third throttling component, the other branch is connected with an outlet of the second throttling component, and an inlet of the second throttling component is connected with a bottom liquid outlet of the gas-liquid separator.

6. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 4, wherein:

the compressor is a two-stage compressor, the high-pressure exhaust port of the compressor is connected with the high-pressure air inlet of the four-way reversing valve, the low-pressure air suction port of the compressor is connected with the low-pressure exhaust port of the four-way reversing valve, and the medium-pressure air suction port of the compressor is connected with the top air outlet of the gas-liquid separator.

7. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 4, wherein:

The compressor comprises a first compressor and a second compressor, wherein an air suction port of the first compressor is connected with an air discharge port of the second compressor, a high-pressure air discharge port of the first compressor is connected with a high-pressure air inlet of the four-way reversing valve, a low-pressure air suction port of the second compressor is connected with a low-pressure air discharge port of the four-way reversing valve, and a top air discharge port of the gas-liquid separator is connected with a connecting pipeline between the first compressor and the second compressor.

8. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 4, wherein:

the compressor comprises a first compressor and a second compressor, outlets of the first compressor and the second compressor are connected with a high-pressure air inlet of the four-way reversing valve, a low-pressure air outlet of the four-way reversing valve is connected with a low-pressure air suction port of the second compressor, and a top air outlet of the gas-liquid separator is connected with a medium-pressure air suction port of the first compressor.

9. The staged compression refrigeration/heating system for temperature and humidity independent air conditioning of claim 4, wherein: the solar heat collector adopts a solar PV/T heat collector for absorbing solar energy and converting the solar energy into electric energy and heat energy, providing heat energy for a fresh air unit for heating fresh air, and also providing heat energy for heating phase-change materials of an energy storage/release unit to realize heat energy storage, wherein the prepared electric energy is used for driving a compressor and a circulating pump to work.

10. A hierarchical compression refrigeration/heating method for a temperature and humidity independent air conditioner is characterized in that: the solar photovoltaic photo-thermal unit, the staged compression unit and the air conditioner energy storage/release unit are operated in a combined mode or an independent mode according to a refrigerating working condition or a heating working condition;

the specific steps of the refrigeration mode are as follows:

when the system operates in a low-temperature cold energy preparation supply mode and a high-temperature cold energy preparation storage and release supply mode, the staged compression unit simultaneously supplies cold energy to the cold energy/heat energy storage tank and the air treatment unit under the condition of night low-valley electricity, the cold energy/heat energy storage tank provides low-grade cold energy for the fresh air unit to treat fresh air load, and the dual-temperature evaporation temperature of the second heat exchanger and the third heat exchanger respectively provides higher-temperature cold energy required by the phase change material cold accumulation process of the cold energy/heat energy storage tank and lower-temperature cold energy required by the air treatment unit to treat wet load of wet air; the third heat exchanger of the refrigeration cycle with high compression ratio is used as a low-temperature evaporator to prepare lower-temperature and higher-grade cold energy to supply the air processing unit with latent heat load and sensible heat load, and the second heat exchanger of the refrigeration cycle with low compression ratio is used as a high-temperature evaporator to prepare higher-temperature and lower-grade cold energy, so that the cold energy is stored in a cold energy/heat energy storage tank and is supplied to a fresh air unit to bear fresh air load;

When the system is operated in a low-temperature cold energy preparation and supply mode and a high-temperature cold energy preparation and storage mode, under the condition of daytime peak electricity, the electric energy prepared by the solar PV/T heat collector is used for driving the compressor and the circulating pump to work, the third heat exchanger of the refrigeration cycle with high compression ratio is used as a low-temperature evaporator to prepare low-temperature and high-grade chilled water to be supplied to the air treatment unit for bearing latent heat load and sensible heat load, and the cold energy of the chilled water once utilized by the air treatment unit is used for providing high-temperature and low-grade cold energy for the fresh air unit through the fifth heat exchanger for bearing fresh air load; the second heat exchanger of the refrigeration cycle with low compression ratio is used as a high-temperature evaporator to prepare cold energy with higher temperature and lower grade and fully stores the cold energy in the cold energy/heat energy storage tank;

when the solar energy PV/T heat collector is operated in a low-temperature cold energy preparation supply mode and a high-temperature cold energy release supply mode, under the condition of daytime peak electricity, the electric energy prepared by the solar energy PV/T heat collector is used for driving a compressor and a circulating pump to work, the refrigeration cycle with a low compression ratio stops working, and only the third heat exchanger of the refrigeration cycle with a high compression ratio is used as a low-temperature evaporator to prepare lower-temperature and higher-grade chilled water to supply an air treatment unit to bear latent heat load and sensible heat load; the higher-temperature cold energy stored in the cold energy/heat energy storage tank is used for bearing fresh air load;

When the solar energy/heat energy storage tank does not store cold energy, the electric energy produced by the solar energy PV/T heat collector is used for driving the compressor and the circulating pump to work, the refrigeration cycle with low compression ratio stops working, the third heat exchanger of the refrigeration cycle with high compression ratio is used as a low-temperature evaporator to produce lower-temperature higher-grade chilled water to supply the air treatment unit to bear latent heat load and sensible heat load, and the rest chilled water cooling capacity after being once utilized by the air treatment unit is used for providing higher-temperature lower-grade cold energy for the fresh air unit to bear fresh air load through the fifth heat exchanger;

the specific steps of the heating mode are as follows:

when the solar radiation intensity is high, the system operates in a low-temperature heat energy preparation, supply, storage and release mode and a high-temperature heat energy preparation and supply mode, wherein the cold energy/heat energy storage tank is used as a high-temperature heat source, outdoor air is used as a low-temperature heat source, the solar PV/T heat collector converts solar energy into electric energy and heat energy, the prepared electric energy is used for driving the compressor and the circulating pump to work, a part of the prepared heat energy is used for directly preheating fresh air, the other part of the prepared heat energy is used for heating the cold energy/heat energy storage tank phase-change material and converting the heat energy into latent heat for storage, the second heat exchanger of the heat pump cycle with the low compression ratio of the stage compression unit is used as a high-temperature evaporator to absorb the latent heat stored by the phase-change material from the energy storage/release unit, and the fourth heat exchanger of the heat pump cycle with the high compression ratio of the stage compression unit is used as a low-temperature evaporator to absorb air heat energy from the outdoor low-temperature environment;

When the solar radiation intensity is weak, the heat pump cycle with low compression ratio is operated according to the modes of low-temperature heat energy release and supply and high-temperature heat energy preparation and supply, outdoor air is used as a low-temperature heat source, the solar energy is converted into electric energy and heat energy by the solar PV/T heat collector, the prepared electric energy is used for driving the compressor and the circulating pump to work, all the prepared heat energy is used for directly preheating fresh air, the fourth heat exchanger of the heat pump cycle with high compression ratio of the grading pressure unit is used as a low-temperature evaporator to absorb air heat energy from the outdoor low-temperature environment, and high-grade high-temperature heat energy is prepared through the single-stage compression process of the compressor and used for heating air conditioner air supply;

when no solar radiation exists, the system operates in a mode of low-temperature heat energy release and supply and high-temperature heat energy preparation and supply, a cold energy/heat energy storage tank is used as a high-temperature heat source, outdoor air is used as a low-temperature heat source, a solar PV/T collector stops working, the prepared electric energy is used for driving a compressor and a circulating pump to work, heat energy stored by a phase-change material of the cold energy/heat energy storage tank is released, part of the heat energy is used for directly preheating fresh air, the other part of the heat energy is used as a high-temperature heat source, a second heat exchanger of a heat pump cycle with a low compression ratio of a stage compression unit is used as a high-temperature evaporator for absorbing latent heat stored by the phase-change material from the energy storage/release unit, a fourth heat exchanger of the heat pump cycle with the low compression ratio of the stage compression unit is used as a low-temperature evaporator for absorbing air heat energy from an outdoor low-temperature environment, heat energy absorbed by the heat pump cycle with the low compression ratio and the heat pump cycle with the high compression ratio is used for heating air conditioner air supply through a stage compression process of the compressor;

When no solar radiation exists and the phase change material of the cold energy/heat energy storage tank does not store latent heat, the phase change material operates in a high-temperature heat energy preparation and supply mode, outdoor air serves as a low-temperature heat source, the low-compression-ratio heat pump cycle stops working, the third heat exchanger of the high-compression-ratio heat pump cycle serves as a condenser to prepare a high-temperature hot water, the higher Gao Pin hot water is supplied to the air treatment unit to bear an air conditioning heat supply load, and the rest hot water heat energy after being once utilized by the air treatment unit is used for providing lower-temperature and lower-grade heat energy for the fresh air unit through the fifth heat exchanger to preheat fresh air.

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