Solar PV / T circulating system integrating thermochemical adsorption cold storage and radiation cooling

Abstract

The invention relates to a solar PV / T circulating system integrating thermochemical adsorption cold storage and radiation cooling. The solar PV / T circulating system comprises loop heat pipe circulation which comprises an integrated radiation cooling PV / T assembly, a photovoltaic controller and a working medium pump. The PV / T assembly is of a turnover structure, the front face of the PV / T assembly is used for absorbing sunlight radiation, and the back face of the PV / T assembly is used for radiation heat exchange to cool the refrigerant. The vapor compression refrigeration cycle comprises a direct-current variable-frequency compressor, a condenser, a first evaporator and a plate heat exchanger; the thermochemical adsorption cold storage cycle comprises an adsorption cold storage unit, a liquid ammonia storage tank and a second evaporator; wherein an adsorbent capable of adsorbing ammonia gas and desorbing and releasing the ammonia gas is loaded in the adsorption cold storage unit. Compared with the prior art, the solar PV / T circulating system has the advantages that collaborative operation of solar photovoltaic cold supply and photo-thermal cold storage can be achieved, the solar energy utilization rate is increased, and all-weather and stable cold supply of the data center can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of solar refrigeration, and in particular to a solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling. Background Art

[0002] Data centers are specialized equipment used to centrally store, process, and manage data and applications. According to statistics, data center energy consumption accounts for about 2% of global electricity consumption, and its huge energy consumption has become one of the focuses of global attention. In recent years, due to the rapid development of new technologies such as artificial intelligence and machine learning, cloud computing, and the Internet of Things, the demand for data centers has surged, resulting in an exponential increase in their energy consumption. In the next decade, their total energy consumption will double or even more. According to surveys, 30% to 50% of the energy consumption of data centers is used for cooling systems, which is the main part of data center energy expenditure. Therefore, it is urgent to promote the green and low-carbon development of data centers, accelerate energy-saving and carbon-reduction transformation, and update energy-consuming equipment.

[0003] By utilizing solar energy, adopting new low-carbon and energy-saving solar cooling technology is a feasible way to reduce the energy consumption of data centers. Solar photovoltaic cooling and solar thermal cooling are common solar cooling methods. However, solar photovoltaic cooling systems rely on photovoltaic panels to convert solar energy into electrical energy, but the photovoltaic conversion efficiency is usually only 15%-22%, and the power generation efficiency of photovoltaic panels decreases with the increase in temperature, and a large part of the solar energy is wasted as heat. On the other hand, solar photovoltaic cooling systems usually need to be equipped with additional batteries to ensure power supply at night, which increases the cost of the system and also brings serious pollution. Solar thermal cooling systems require the installation of large-area collectors and other equipment, occupying a large space, and the design is usually more complex, with high maintenance costs, making them difficult to promote.

[0004] CN103884143A discloses a cold storage refrigerator system of solar photovoltaic refrigeration and adsorption refrigeration, which can combine solar photovoltaic refrigeration and adsorption refrigeration to achieve all-weather refrigeration. However, the cold storage refrigerator system cannot effectively utilize radiation cooling and waste heat regeneration, has low solar energy utilization rate, relies on power grid backup, and generally only supports household use scenarios, and cannot meet the cold storage needs of large data centers.

[0005] Therefore, in order to meet the high cooling demand in application scenarios such as large data centers and communication base stations, it is urgent to develop a new type of solar PV / T cycle system. Summary of the invention

[0006] The purpose of the present invention is to provide a solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling in order to solve at least one of the problems existing in existing solar photovoltaic refrigeration, namely, low solar energy utilization rate, dependence on the power grid, and inapplicability to large data centers.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling, the solar PV / T cycle system comprising:

[0009] A loop heat pipe circulation subsystem, which includes a PV / T component with integrated radiation cooling, a photovoltaic controller connected to the PV / T component, and a working fluid pump for transmitting a refrigerant to the PV / T component; wherein the PV / T component is a reversible structure, the front side of which is used to absorb solar radiation, and the back side of which is used for radiation heat exchange to cool the refrigerant;

[0010] A vapor compression refrigeration cycle subsystem, the subsystem comprising a DC variable frequency compressor connected to a photovoltaic controller and a condenser connected to the DC variable frequency compressor; the outlet of the condenser is respectively connected to a first evaporator and a plate heat exchanger, and the outlets of the first evaporator and the plate heat exchanger are both connected to the DC variable frequency compressor;

[0011] A thermochemical adsorption cold storage circulation subsystem, which includes an adsorption cold storage unit, a liquid ammonia storage tank and a second evaporator; the adsorption cold storage unit, the plate heat exchanger, the liquid ammonia storage tank and the second evaporator are connected end to end to form a closed loop, and the fluid outlet of the adsorption cold storage unit is connected to a working fluid pump; wherein the adsorption cold storage unit is loaded with an adsorbent capable of adsorbing ammonia and desorbing and releasing ammonia.

[0012] Furthermore, the PV / T assembly includes a glass cover plate, a first packaging layer, a photovoltaic cell, a second packaging layer, an insulating plate, a blown heat exchange back plate, a radiation cooling film and an anti-convection cover plate which are arranged layer by layer.

[0013] Furthermore, a working medium flow channel for the cooling working medium to flow is formed in the inflation type heat exchange back plate.

[0014] Furthermore, when the power generation of the PV / T assembly is small, the photovoltaic controller supplies all the electricity to the DC variable frequency compressor.

[0015] Furthermore, when the power generation of the PV / T assembly is large, the photovoltaic controller will supply the surplus power after supplying the DC variable frequency compressor to the data center for use or be incorporated into the power grid.

[0016] Furthermore, a first expansion valve is provided between the outlet of the condenser and the first evaporator.

[0017] Furthermore, a second expansion valve is provided between the outlet of the condenser and the plate heat exchanger.

[0018] Furthermore, a third expansion valve is provided between the outlet of the liquid ammonia storage tank and the second evaporator.

[0019] Furthermore, the refrigerants used in the loop heat pipe circulation subsystem, the vapor compression refrigeration circulation subsystem and the thermochemical adsorption cold storage circulation subsystem are R1233zd(E), R290 and R717 respectively.

[0020] Furthermore, the solar PV / T cycle system has a daytime cooling / cold storage mode and a nighttime cold release mode.

[0021] In the daytime cooling / cold storage mode, the PV / T component supplies power to the DC variable frequency compressor, the vapor compression refrigeration cycle starts to run, and the refrigerant is input into the first evaporator and / or the plate heat exchanger; when the solar radiation is sufficient, the loop heat pipe cycle and the thermochemical adsorption cold storage cycle start to run, and the refrigerant flows through the PV / T component through the working fluid pump to absorb the radiation heat and then enter the adsorption cold storage unit, releasing ammonia under the action of the adsorbent, and the ammonia flows through the plate heat exchanger and is stored in the liquid ammonia storage tank.

[0022] In the night cooling mode, the liquid ammonia in the liquid ammonia storage tank is input into the second evaporator to release cold, and then enters the adsorption cold storage unit and is adsorbed by the adsorbent to release heat; the refrigerant in the loop heat pipe circulation flows through the adsorption cold storage unit through the working fluid pump to evaporate and absorb heat, and then flows through the flipped PV / T module to radiate heat to the sky to cool the refrigerant.

[0023] In areas with large temperature differences between day and night, the PV / T assembly does not need to be flipped over, and the refrigerant can be cooled by long-wave radiation heat exchange between the PV / T assembly and the sky and convection heat exchange with the environment.

[0024] Furthermore, in the night cooling mode, when the night temperature is high, the cooling capacity released by the second evaporator is insufficient, power is supplied to the DC variable frequency compressor through the power grid, the vapor compression refrigeration cycle starts to run, and the refrigerant is input into the first evaporator to supplement the cooling capacity; when the night temperature drops, the vapor compression refrigeration cycle is closed, and the cooling capacity continues to be released through the second evaporator.

[0025] Furthermore, the adsorbent includes NaBr, NH 4 Cl and BaCl 2 Any one or more of the expanded graphite composite adsorbents.

[0026] Furthermore, the adsorbent is BaCl 2 composite adsorbent.

[0027] Furthermore, the composite adsorbent is composed of BaCl 2 , sulfided expanded graphite and carbon-coated aluminum nanoparticles, and the mass fractions of the three in the adsorbent are 80%, 18% and 2%, respectively.

[0028] Furthermore, the composite adsorbent is prepared by the following method:

[0029] S1: drying barium chloride, sulfide expanded graphite and carbon-coated aluminum nanoparticles for later use;

[0030] S2: dispersing carbon-coated aluminum nanoparticles in water and ultrasonically dispersing to obtain a uniform suspension;

[0031] S3: adding barium chloride and sulfide expanded graphite into the uniform suspension of carbon-coated aluminum nanoparticles, and stirring to mix evenly;

[0032] S4: Dry the mixed solution to obtain a powdered composite adsorbent.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The solar PV / T cycle system of the present invention integrates photovoltaic / thermal technology (PV / T), thermochemical adsorption cold storage technology and radiation cooling technology, realizing the coordinated operation of solar photovoltaic cooling and photothermal cold storage. The solar energy utilization rate can be increased to 60%-70%, which can effectively ensure the all-weather, efficient and stable cooling supply of the data center.

[0035] (2) The present invention combines PV / T and thermochemical adsorption cold storage technology, and realizes centralized cold storage by using photothermal conversion to provide driving heat source for adsorption bed. Considering that users ultimately need cooling capacity, it is more efficient to use cold storage instead of electricity storage. At the same time, the system also overcomes the disadvantages of traditional solar refrigeration systems that rely on highly polluting and high-cost batteries to achieve nighttime operation. On the other hand, the system uses photovoltaic direct drive technology to directly use photovoltaic power for system equipment operation, reducing energy conversion losses, improving system efficiency, simplifying system structure, and avoiding dependence on batteries.

[0036] (3) The present invention effectively combines radiation cooling technology and thermochemical adsorption cold storage technology. The adsorption heat of the adsorption bed is released through the radiation cooling effect of the PV / T panel at night, solving the pain point that the adsorption heat of the traditional thermochemical adsorption cold storage technology is difficult to discharge with zero energy consumption, thereby realizing the system's zero-energy consumption and continuous cooling at night.

[0037] (4) The present invention adopts a "dual evaporator" design and uses a dynamic strategy to adjust the system working mode to achieve continuous, efficient and stable output of cooling capacity all day long; in addition, the solar PV / T cycle system of the present invention has the characteristics of green environmental protection and low carbon emissions, providing an ideal solution for the efficient and economical utilization of renewable energy (solar energy). BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1It is a schematic structural diagram of the solar PV / T cycle system of the present invention.

[0039] Figure 2 Schematic diagram of the structure of the PV / T component.

[0040] Description of the markings in the figure:

[0041] 1-PV / T assembly, 1.1-glass cover plate, 1.2-first packaging layer, 1.3-photovoltaic cell, 1.4-second packaging layer, 1.5-insulating plate, 1.6-blown heat exchange back plate, 1.7-radiation cooling film, 1.8-anti-convection cover plate, 1.9-working fluid flow channel; 2-photovoltaic controller; 3-working fluid pump; 4-DC variable frequency compressor; 5-condenser; 6-first evaporator; 7-plate heat exchanger; 8-adsorption cold storage unit; 9-liquid ammonia storage tank; 10-second evaporator; 11-first expansion valve; 12-second expansion valve; 13-third expansion valve. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0043] In the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0045] Embodiment 1:

[0046] This embodiment provides a solar PV / T cycle system integrating thermal chemical adsorption cold storage and radiation cooling, such as Figure 1 As shown, it specifically includes a loop heat pipe cycle, a vapor compression refrigeration cycle and a thermochemical adsorption cold storage cycle.

[0047] The loop heat pipe cycle of this embodiment includes a PV / T module 1 with integrated radiation cooling, a photovoltaic controller 2 connected to the PV / T module 1, and a working fluid pump 3 for transmitting a refrigerant to the PV / T module 1. The PV / T module 1 is a reversible structure, the front side of which is used to absorb solar radiation, and the back side of which is used for radiation heat exchange to cool the refrigerant, innovatively integrating radiation cooling technology into solar cell modules.

[0048] The vapor compression refrigeration cycle of this embodiment includes a DC variable frequency compressor 4 connected to the photovoltaic controller 2 and a condenser 5 connected to the DC variable frequency compressor 4. The outlet of the condenser 5 is connected to the first evaporator 6 and the plate heat exchanger 7 respectively, and the outlets of the first evaporator 6 and the plate heat exchanger 7 are both connected to the DC variable frequency compressor 4.

[0049] The thermochemical adsorption cold storage cycle of this embodiment includes an adsorption cold storage unit 8, a liquid ammonia storage tank 9 and a second evaporator 10. In the entire system, the adsorption cold storage unit 8, the plate heat exchanger 7, the liquid ammonia storage tank 9 and the second evaporator 10 are connected end to end to form a closed loop, and the fluid outlet of the adsorption cold storage unit 8 is connected to the working fluid pump 3. Among them, the adsorption cold storage unit 8 of this embodiment is loaded with an adsorbent, which can adsorb ammonia or desorb and release ammonia in different operating modes.

[0050] This embodiment realizes efficient utilization of solar energy by integrating the multi-cycle system of loop heat pipe cycle, vapor compression refrigeration cycle and thermochemical adsorption cold storage cycle and utilizing energy in a cascade manner, while performing photoelectric refrigeration and photothermal cold storage. In addition, the present invention uses a thermochemical adsorption cold storage cycle to replace the high-cost and high-pollution storage batteries used in traditional solar electric drive refrigeration systems, which can effectively ensure the all-weather, efficient and stable supply of cold to the data center.

[0051] Embodiment 2:

[0052] The present embodiment provides a solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling, which specifically includes a loop heat pipe cycle, a vapor compression refrigeration cycle and a thermochemical adsorption cold storage cycle.

[0053] The difference from Example 1 is that Figure 2As shown, the PV / T assembly 1 of this embodiment includes a glass cover plate 1.1, a first packaging layer 1.2, a photovoltaic cell 1.3, a second packaging layer 1.4, an insulating plate 1.5, a blown heat exchange back plate 1.6, a radiation cooling film 1.7 and an anti-convection cover plate 1.8. A working medium flow channel 1.9 for the flow of cooling working medium is formed in the blown heat exchange back plate 1.6.

[0054] Specifically, the glass cover plate 1.1 is used as the outermost protective layer, and is made of tempered glass with high light transmittance (>92%). The first encapsulation layer 1.2 and the second encapsulation layer 1.4 double-sidedly encapsulate the photovoltaic cell 1.3, usually using ethylene-vinyl acetate copolymer (EVA) or POE adhesive film with good light transmittance. The insulating plate 1.5 is located between the photovoltaic cell 1.3 and the inflatable heat exchange backplane 1.6, and is usually made of polyimide or ceramic-based composite materials to isolate the circuit and conduct heat efficiently. The inflatable heat exchange backplane 1.6 is used as the core heat exchange structure, and the working fluid flow channel 1.9 is formed by the inflating process of aluminum or copper materials. The working fluid flow channel 1.9 adopts a serpentine or fractal design to ensure the uniform flow of the cooling medium. The radiation cooling film 1.7 is the core of the back radiation heat dissipation, which is composed of multiple layers of photonic crystals or polymer-metal composite films, and dissipates heat directly into the air through radiation heat dissipation. The anti-convection cover 1.8 is located at the bottom layer and is made of vacuum-coated glass or aerogel composite panels. The microporous structure or vacuum layer inside it reduces the heat loss caused by air convection.

[0055] During the day, the photovoltaic cell 1.3 of the PV / T assembly 1 absorbs a large amount of radiant heat under the irradiation of sunlight; at the same time, the working fluid flows through the working fluid flow channel 1.9, and takes away the absorbed solar radiant heat through the evaporation process; the working fluid that has absorbed the solar radiant heat flows through the adsorption cold storage unit 8 driven by the working fluid pump 3, and then releases the heat to the adsorption cold storage unit 8 through the condensation process.

[0056] At night, the PV / T module 1 is turned over, and the working fluid pump 3 drives the working fluid to flow through the adsorption cold storage unit 8, and the adsorption heat is taken away through the evaporation process; then the working fluid flows through the turned PV / T module 1 again, and the radiation refrigeration film 1.7 covered on the back thereof performs radiant heat exchange with the sky, which can cool the working fluid flowing through the PVT module, so that the working fluid can dissipate the adsorption heat through the condensation process.

[0057] The double-sided reversible PV / T module 1 of this embodiment is combined with the radiation cooling technology to perform photovoltaic power generation and light heat recovery during the day and radiation cooling and cold storage release at night, thereby achieving 24-hour efficient and stable cooling.

[0058] Embodiment 3:

[0059] The present embodiment provides a solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling, which specifically includes a loop heat pipe cycle, a vapor compression refrigeration cycle and a thermochemical adsorption cold storage cycle.

[0060] The difference from Example 1 is that, when the power generation of the PV / T assembly 1 of this embodiment is small, the photovoltaic controller 2 supplies all the power to the DC variable frequency compressor 4. When the power generation of the PV / T assembly 1 is large, the photovoltaic controller 2 supplies the surplus power after supplying the DC variable frequency compressor 4 to the data center for use or to the power grid.

[0061] Specifically, the PV / T assembly 1 circulating in the loop heat pipe generates direct current under sunlight, and directly drives the DC variable frequency compressor 4 through the photovoltaic controller 2. The stronger the solar radiation, the greater the power generation of the PV / T assembly 1. When the power generation is small, the MPPT photovoltaic controller 2 supplies all the power to the DC variable frequency compressor 4; when the power generation is large and the DC variable frequency compressor 4 is working at the highest frequency, the MPPT photovoltaic controller 2 supplies the surplus power to the data center or connects it to the power grid.

[0062] Embodiment 4:

[0063] The present embodiment provides a solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling, which consists of a loop heat pipe cycle, a vapor compression refrigeration cycle and a thermochemical adsorption cold storage cycle, and uses R1233zd (E), R290 and R717 (ammonia) as refrigerants respectively.

[0064] The loop heat pipe cycle includes a PV / T component 1, an MPPT photovoltaic controller 2, and a working fluid pump 3.

[0065] During the day, the photovoltaic panels of the PV / T assembly 1 generate direct current under the sunlight, and the MPPT photovoltaic controller 2 directly drives the DC variable frequency compressor 4 to work. The surplus electricity is supplied to the data center or connected to the power grid. At the same time, the PV / T assembly 1 absorbs a large amount of radiant heat under the sunlight. The R1233zd (E) working fluid flows through the PV / T assembly 1 driven by the working fluid pump 3, and takes away the solar radiant heat absorbed by the PV / T assembly 1 through the evaporation process, effectively reducing the temperature of the PV / T assembly 1, keeping its maximum temperature below 55°C, which is conducive to improving the photoelectric conversion efficiency of the PV / T assembly 1. The R1233zd (E) working fluid that absorbs the solar radiant heat then flows through the adsorption cold storage unit 8, and releases the heat to the adsorption cold storage unit 8 through the condensation process. At night, the working fluid pump 3 drives the R1233zd(E) working fluid to flow through the adsorption cold storage unit 8, and takes away the adsorption heat through the evaporation process. Then the R1233zd(E) working fluid flows through the flipped PVT component 1, and the radiation refrigeration film 1.7 covering the back side thereof performs radiation cooling on the sky, cooling the working fluid flowing through the PVT component 1, so that the R1233zd(E) working fluid can dissipate the adsorption heat through the condensation process.

[0066] The vapor compression refrigeration cycle includes a DC variable frequency compressor 4, a condenser 5, a first expansion valve 11, a plate heat exchanger 7, a second expansion valve 12, and a first evaporator 6. The cycle adopts a parallel structure. After the R290 refrigerant passes through the DC variable frequency compressor 4 and the condenser 5, a part of the R290 refrigerant passes through the first expansion valve 11 to provide cooling in the first evaporator 6 and provide an outlet air temperature of 5°C to meet the cooling demand of the data center. The other part of the R290 refrigerant passes through the second expansion valve 12 and enters the cold fluid flow channel of the plate heat exchanger 7 to exchange heat with the ammonia working medium in the hot fluid flow channel.

[0067] The thermochemical adsorption cold storage cycle includes an adsorption cold storage unit 8, a liquid ammonia storage tank 9, a third expansion valve 13, and a second evaporator 10. During the day, the adsorbent in the adsorption cold storage unit 8 absorbs the heat of the loop heat pipe to undergo a desorption reaction to release ammonia. The desorbed ammonia enters the hot fluid flow channel of the plate heat exchanger 7. At the same time, the R290 refrigerant evaporates and refrigerates in the cold fluid flow channel of the plate heat exchanger 7 and condenses the ammonia, thereby reducing the heating desorption pressure and driving temperature of the adsorption cold storage unit. The ammonia is condensed into liquid ammonia and stored in the liquid ammonia storage tank 9. The adsorption cold storage unit 8 is an adsorption bed filled with adsorbent. At night, the liquid ammonia accumulated in the liquid ammonia storage tank 9 is throttled by the third expansion valve 13 and then enters the second evaporator 10 for evaporation, providing an outlet air temperature of 5°C to meet the cooling needs of the data center. After the ammonia flows into the adsorption bed 11, it is adsorbed by the adsorbent in the adsorption bed, and the generated adsorption heat is released to the loop heat pipe.

[0068] In this example, the system is divided into two working modes: daytime cooling / cold storage mode and nighttime cold release mode. The processes of the two working modes are as follows:

[0069] Daytime cooling / cold storage mode: When solar radiation is weak during the day, all the electricity generated by the PV / T component 1 is supplied to the DC variable frequency compressor 4. At the same time, the power grid is used to supplement part of the electricity for the DC variable frequency compressor 4, so that the DC variable frequency compressor 4 can operate at a preset speed to drive the vapor compression refrigeration cycle. After the R290 refrigerant passes through the DC variable frequency compressor and the condenser, it provides continuous and stable cooling capacity at the evaporator 1.

[0070] During the day, when solar radiation is strong, the PV / T module 1 can directly drive the DC variable frequency compressor 4 to operate at a preset speed, and the surplus electricity can be supplied to the data center or connected to the power grid.

[0071] When the solar radiation intensity is sufficient during the day, the speed of the DC variable frequency compressor 4 is increased. After the R290 refrigerant passes through the DC variable frequency compressor 4 and the condenser 5, a part of the R290 refrigerant passes through the first expansion valve 11 to ensure that the first evaporator 6 can provide continuous and stable cooling capacity, and the other part of the R290 refrigerant passes through the second expansion valve 12 and enters the cold fluid flow channel of the plate heat exchanger 7. At the same time, the circulating pump 4 of the loop heat pipe circulation is turned on to drive the R1233zd (E) refrigerant to flow through the PV / T component 1, and take away the solar radiation heat absorbed by the PV / T component 1 through the evaporation process. The R1233zd (E) refrigerant that absorbs the solar radiation heat then flows through the adsorption cold storage unit 8, and releases the heat to the adsorption cold storage unit 8 through the condensation process. After absorbing heat, the adsorbent in the adsorption cold storage unit 8 undergoes a desorption reaction to release ammonia. The desorbed ammonia enters the hot fluid flow channel of the plate heat exchanger 7. At the same time, the R290 refrigerant evaporates and cools in the cold fluid flow channel of the plate heat exchanger 7 to condense the ammonia, thereby reducing the heating desorption pressure and driving temperature of the adsorption cold storage unit 8. The ammonia is condensed into liquid ammonia and stored in the liquid ammonia storage tank 9 to realize the daytime cold storage of the thermochemical adsorption cold storage cycle.

[0072] Nighttime cold storage mode: At night, the liquid ammonia accumulated in the liquid ammonia storage tank 9 is throttled by the third expansion valve 13 and then enters the second evaporator 10 to evaporate and release cold. After the ammonia flows out of the second evaporator 10 and enters the adsorption cold storage unit 8, it is adsorbed by the adsorbent in the adsorption cold storage unit 8 to generate adsorption heat. At the same time, the working fluid pump 3 of the loop heat pipe circulation is turned on to drive the R1233zd (E) working fluid to flow through the adsorption cold storage unit 8, and the adsorption heat is taken away through the evaporation process. Then, the R1233zd (E) working fluid flows through the flipped PVT component 1, and the radiation refrigeration film 1.7 covered on the back thereof performs radiant heat exchange with the sky, cooling the R1233zd (E) working fluid flowing through the PVT component 1, so that the R1233zd (E) working fluid can dissipate the adsorption heat through the condensation process.

[0073] When the temperature is still high at night, the ability to dissipate adsorption heat is weak, and less ammonia refrigerant can be throttled by the third expansion valve 13. The cold released in the second evaporator 10 is insufficient. At this time, the power grid supplies power to the DC variable frequency compressor 4, driving the vapor compression refrigeration cycle to operate, replenishing part of the cold in the first evaporator 6, and realizing a continuous and stable output of cold through the "double evaporator" strategy. As the temperature decreases at night, the ability to dissipate adsorption heat gradually increases. At this time, the vapor compression refrigeration cycle is closed, and only the second evaporator 10 is used to achieve a continuous and stable output of cold. In areas with large temperature differences between day and night, the PV / T components do not need to be flipped, and the refrigerant can be cooled by the long-wave radiation heat exchange between the PV / T components and the sky and the convection heat exchange with the environment.

[0074] Embodiment 5:

[0075] The present embodiment provides a solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling, which specifically includes a loop heat pipe cycle, a vapor compression refrigeration cycle and a thermochemical adsorption cold storage cycle.

[0076] The adsorbent used in this embodiment can be selected from conventional commercially available NaBr and NH 4 Cl, BaCl 2 The expanded graphite composite adsorbent is 3 The reversible reaction realizes adsorption and desorption in different scenarios.

[0077] This embodiment provides a preferred composite adsorbent, which contains BaCl 2 ENG-TSA / Al@C / BaCl 2 In the composite adsorbent, barium chloride (BaCl 2 ), sulfide expanded graphite (ENG-TSA), and carbon-coated aluminum nanoparticles (Al@C) have a mass fraction of 80%, 18%, and 2%, respectively. The specific preparation method is as follows:

[0078] S1: Place barium chloride, sulfide expanded graphite and carbon-coated aluminum nanoparticles in a 120°C oven for drying pretreatment to ensure that the materials are dry.

[0079] S2: Weigh carbon-coated aluminum nanoparticles, place them in deionized water, and ultrasonically vibrate for 30 minutes to obtain a uniform suspension.

[0080] S3: Weigh barium chloride and sulfide expanded graphite, add the barium chloride and sulfide expanded graphite into the uniform suspension of carbon-coated aluminum nanoparticles, and stir and mix them evenly with a magnetic stirrer.

[0081] S4: Put the mixed solution into an oven for drying, set the oven temperature to 120°C, stir it several times during the drying process to avoid agglomeration and precipitation of barium chloride, and ensure that the adsorbent material is evenly mixed. After drying, the adsorbent powder can be obtained.

[0082] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling, characterized in that: The solar PV / T cycle system comprises: A loop heat pipe cycle, comprising a PV / T component (1) with integrated radiation cooling, a photovoltaic controller (2) connected to the PV / T component (1), and a working fluid pump (3) for transmitting a refrigerant to the PV / T component (1); wherein the PV / T component (1) is a reversible structure, the front side of which is used to absorb solar radiation, and the back side of which is used for radiation heat exchange to cool the refrigerant; A vapor compression refrigeration cycle, comprising a DC variable frequency compressor (4) connected to a photovoltaic controller (2) and a condenser (5) connected to the DC variable frequency compressor (4); the outlet of the condenser (5) is respectively connected to a first evaporator (6) and a plate heat exchanger (7), and the outlets of the first evaporator (6) and the plate heat exchanger (7) are both connected to the DC variable frequency compressor (4); A thermochemical adsorption cold storage cycle; comprising an adsorption cold storage unit (8), a liquid ammonia storage tank (9) and a second evaporator (10); the adsorption cold storage unit (8), the plate heat exchanger (7), the liquid ammonia storage tank (9) and the second evaporator (10) are connected end to end to form a closed loop, and the fluid outlet of the adsorption cold storage unit (8) is connected to a working fluid pump (3); wherein the adsorption cold storage unit (8) is loaded with an adsorbent capable of adsorbing ammonia and desorbing and releasing ammonia.

2. A solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 1, characterized in that: The PV / T assembly (1) comprises a glass cover plate (1.1), a first packaging layer (1.2), a photovoltaic cell (1.3), a second packaging layer (1.4), an insulating plate (1.5), a blown heat exchange back plate (1.6), a radiation cooling film (1.7) and an anti-convection cover plate (1.8) which are arranged layer by layer.

3. A solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 2, characterized in that: A working medium flow channel (1.9) for the flow of cooling working medium is formed in the inflation-type heat exchange back plate (1.6).

4. The solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 1 is characterized in that: When the power generation of the PV / T assembly (1) is relatively small, the photovoltaic controller (2) supplies all the power to the DC variable frequency compressor (4); When the power generation of the PV / T assembly (1) is relatively large, the photovoltaic controller (2) supplies the surplus power after supplying the DC variable frequency compressor (4) to the data center for use or to the power grid.

5. The solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 1, characterized in that: A first expansion valve (11) is provided between the outlet of the condenser (5) and the first evaporator (6), a second expansion valve (12) is provided between the outlet of the condenser (5) and the plate heat exchanger (7), and a third expansion valve (13) is provided between the outlet of the liquid ammonia storage tank (9) and the second evaporator (10).

6. The solar PV / T cycle system integrating thermal chemical adsorption cold storage and radiation cooling according to claim 1 is characterized in that: The refrigerants used in the loop heat pipe cycle, the vapor compression refrigeration cycle and the thermochemical adsorption cold storage cycle are R1233zd(E), R290 and R717 respectively.

7. The solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 1, characterized in that: The solar PV / T cycle system has a daytime cooling / cold storage mode and a nighttime cold release mode; In the daytime cooling / cold storage mode, the PV / T assembly (1) supplies power to the DC variable frequency compressor (4), the vapor compression refrigeration cycle starts to operate, and the refrigerant is input into the first evaporator (6) and / or the plate heat exchanger (7); When the solar radiation is sufficient, the loop heat pipe cycle and the thermochemical adsorption cold storage cycle start to operate, the refrigerant flows through the PV / T module (1) through the working fluid pump (3), absorbs the radiation heat, and is then input into the adsorption cold storage unit (8), where ammonia is released under the action of the adsorbent. The ammonia flows through the plate heat exchanger (7) and is stored in the liquid ammonia storage tank (9); In the night cooling mode, the liquid ammonia in the liquid ammonia storage tank (9) is input into the second evaporator (10) to release cold energy, and then enters the adsorption cold storage unit (8) and is adsorbed by the adsorbent to release heat; the refrigerant in the loop heat pipe circulation flows through the adsorption cold storage unit (8) through the working fluid pump (3) to evaporate and absorb heat, and then flows through the flipped PV / T module (1) to perform radiant heat exchange with the sky to cool the refrigerant.

8. The solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 7 is characterized in that: In the night cooling mode, when the night temperature is high, the cooling capacity released by the second evaporator (10) is insufficient, and power is supplied to the DC variable frequency compressor (4) through the power grid, the vapor compression refrigeration cycle starts to operate, and the refrigerant is input into the first evaporator (6) to supplement the cooling capacity; when the night temperature drops, the vapor compression refrigeration cycle is closed, and the cooling capacity continues to be released through the second evaporator (10); In areas where the temperature difference between day and night is large, the PV / T assembly (1) does not need to be turned over, and the refrigerant is cooled by the long-wave radiation heat exchange between the PV / T assembly (1) and the sky and the convection heat exchange with the environment.

9. The solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 1, characterized in that: The adsorbent includes any one or more of NaBr, NH4Cl and an expanded graphite composite adsorbent containing BaCl2.

10. The solar PV / T cycle system integrating thermochemical adsorption cold storage and radiation cooling according to claim 1, characterized in that: The adsorbent is a composite adsorbent containing BaCl2; The composite adsorbent is composed of BaCl2, sulfide expanded graphite and carbon-coated aluminum nanoparticles, and the mass fractions of the three in the adsorbent are 80%, 18% and 2% respectively; The adsorbent is prepared by the following method: S1: drying barium chloride, sulfide expanded graphite and carbon-coated aluminum nanoparticles for later use; S2: dispersing carbon-coated aluminum nanoparticles in water and ultrasonically dispersing to obtain a uniform suspension; S3: adding barium chloride and sulfide expanded graphite into the uniform suspension of carbon-coated aluminum nanoparticles, and stirring to mix evenly; S4: Dry the mixed solution to obtain a powdered composite adsorbent.

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