Photovoltaic direct drive, light and heat direct expansion based light and heat storage flexible high-efficiency energy utilization system

Abstract

The application discloses a kind of based on photovoltaic direct drive, light heat direct swelling light heat storage flexible high-efficiency energy utilization system, including the heat pump air conditioning system based on direct swelling photovoltaic photo-thermal component and the high-efficiency photovoltaic direct drive energy supply system for powering heat pump air conditioning system.Have at least heat storage module and cold storage module in heat pump air conditioning system, heat storage module stores heat in heat storage mode, and enters energy storage heat output mode to release heat for direct swelling photovoltaic photo-thermal component defrosting in low temperature working condition;Cold storage module can store cold in low temperature environment, and direct swelling photovoltaic photo-thermal component is refrigerated using cold in high temperature environment.Compared with prior art, photovoltaic direct drive, light heat direct swelling light heat storage flexible high-efficiency energy utilization system not only can optimize the working environment of direct swelling photovoltaic photo-thermal component, improve its power generation, but also can create more suitable working condition for heat pump air conditioning high-efficiency energy supply, so as to improve system energy efficiency, increase customer economic benefit.

Description

Technical Field

[0001] This invention relates to the field of refrigeration, and in particular to a photovoltaic direct drive and photothermal direct expansion photovoltaic thermal storage flexible and efficient energy utilization system. Background Technology

[0002] To achieve the ambitious "3060" carbon emission reduction goal, it is necessary to vigorously develop new energy technologies. Because the energy projected onto Earth by the sun is enormous, reaching 1.73 × 10¹⁷ W, equivalent to the total power output of 173 million megawatt-class power plants—many times greater than the total energy used by humanity annually across all types—photovoltaic power generation technology is considered one of the most promising new energy technologies. However, photovoltaic power generation suffers from significant drawbacks, including large fluctuations in performance over time and seasons, and its inability to respond to dynamic user demands. This results in the waste of surplus energy and a poor user experience due to the failure to meet user needs.

[0003] In the operation of traditional heat pump air conditioners, the compressor driven by the mains power supply needs to be converted to DC by the main control board and then to AC power suitable for the compressor. There is an "AC-DC-AC" energy conversion process. If we consider that the photovoltaic power generation is connected to the grid through the inverter and then supplies power to the heat pump air conditioner compressor, there is a "DC-AC-DC-AC" energy conversion process. The realization of this process greatly increases the energy loss rate.

[0004] Key issues to be addressed in the use of photovoltaic (PV) power generation: Theoretically, better sunshine conditions and stronger sunlight result in more irradiant energy reaching the PV panels, leading to greater power generation. However, PV panels suffer from a significant decrease in power generation efficiency as their temperature rises. Better sunshine conditions cause a substantial increase in the operating temperature of the PV modules, drastically reducing their efficiency. However, if the waste heat generated by sunlight during PV operation is promptly removed, not only can a good operating temperature for the PV modules be maintained, but heat output can also be increased without increasing the PV area, achieving a dual benefit.

[0005] CN104113078B discloses a photovoltaic direct-drive system and its control method. The method includes the following steps: based on the energy balance relationship between the photovoltaic unit, load unit, and grid unit in the photovoltaic direct-drive system, a voltage outer loop and current inner loop control method is used to control the grid-side converter of the grid unit; based on the mathematical model of the load in the load unit in the synchronous rotating coordinate system, a model reference adaptive control method is used to control the load operation; and based on the dynamic load tracking (MPPT) adaptive step size control method, the photovoltaic unit is controlled. By employing different control methods to control the photovoltaic unit, load unit, and grid unit in the photovoltaic direct-drive system respectively, three-element linkage control in the photovoltaic direct-drive system is realized, thereby achieving bidirectional energy flow and real-time grid connection. This effectively solves the problems of existing photovoltaic air conditioning systems being unable to achieve real-time grid connection and unable to achieve full DC grid connection technology.

[0006] CN113028480A discloses a solar photovoltaic heat pump microgrid system, including photovoltaic modules, a passive solar house formed by installing the photovoltaic modules at a preset angle and with sealing components, and a storage battery, a storage inverter, a control cabinet, and an air source heat pump connected in sequence inside the passive solar house. The air source heat pump is connected to a heat exchanger through a circulation pipeline to form a closed loop. The heat exchanger is connected to a hot water storage tank, and the photovoltaic modules are connected to the energy storage inverter. The air source heat pump absorbs the heat energy generated by the photovoltaic modules during operation and the heat energy received by the passive solar house, storing it in the hot water storage tank, thereby reducing the temperature inside the passive solar house and greatly improving the comprehensive utilization rate of solar energy.

[0007] CN118089194A proposes a control method for a photovoltaic direct-drive air conditioning and lighting system, including a photovoltaic direct-drive system comprising a photovoltaic unit, a user unit, a power grid unit, and a control system. The user unit includes an air conditioning system and a lighting system. The control system is connected to the photovoltaic unit, the load unit, and the power grid unit to achieve control. This invention integrates the air conditioning system, the lighting system, the photovoltaic unit, and the power grid unit into a photovoltaic direct-drive system, with a through-hole control system providing unified control. Through the control system, the power consumption of the air conditioning system and the lighting system is matched with the power generation of the photovoltaic unit in real time, effectively improving the utilization rate of solar power generation and reducing building energy consumption.

[0008] CN204612240U discloses a heat pump type photovoltaic-thermal composite device, belonging to the field of solar photovoltaic-thermal technology. Its structure includes a photovoltaic panel and a compressor. The back surface of the photovoltaic panel directly or indirectly transfers heat to an evaporator. The photovoltaic panel outputs DC power to connect to a photovoltaic heat pump driver, which drives the compressor. A circulation pipeline sequentially connects the compressor, a water-cooled condenser, a throttling device, and an evaporator. The compressor, water-cooled condenser, throttling device, and evaporator are connected through the circulation pipeline to form a gas-liquid heat circulation mechanism. The circulation pipeline connects to the tube side of the water-cooled condenser, the inlet pipeline connects to the shell side of the water-cooled condenser, and the shell side of the water-cooled condenser connects to the outlet pipeline. This heat pump type photovoltaic-thermal composite device utilizes the DC power of the photovoltaic module itself to drive a heat pump, thereby reducing the module's own temperature and outputting heat energy, while simultaneously improving the photoelectric conversion efficiency.

[0009] As can be seen from the above introduction, although photovoltaic direct drive systems and heat pump air conditioners have good benefits in their respective fields, there is still a significant energy waste for a single photovoltaic direct drive system or heat pump air conditioner. Therefore, how to design a photovoltaic direct drive and photovoltaic thermal expansion flexible and efficient energy utilization system to improve energy utilization efficiency is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0010] To address the problem of low energy utilization efficiency in existing technologies, this invention proposes a flexible and efficient energy utilization system based on photovoltaic direct drive and photovoltaic thermal expansion.

[0011] The technical solution of the present invention is to propose a photovoltaic direct drive and photovoltaic thermal expansion-based photovoltaic thermal storage flexible high-efficiency energy utilization system, including a heat pump air conditioning system and a photovoltaic direct drive system for supplying power to the heat pump air conditioning system; The heat pump air conditioning system has at least a thermal energy storage module and a cold energy storage module. The thermal energy storage module can store heat in the refrigerant in the heat storage mode and release the heat in the refrigerant in the defrost mode to defrost the direct expansion photovoltaic thermal modules in the photovoltaic direct drive system. The cold energy storage module can store the cold energy in the refrigerant in a low-temperature environment and use the cold energy to cool the direct expansion photovoltaic thermal module in the photovoltaic direct drive system in a high-temperature environment.

[0012] Furthermore, the heat pump air conditioning system has an energy storage heat input mode; When the heat pump air conditioning system is operating in the energy storage heat input mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, indoor heat exchanger, heat storage unit, throttling device, direct expansion photovoltaic thermal module, four-way valve, gas-liquid separator, compressor; In the energy storage heat input mode, the heat storage module stores the heat in the refrigerant.

[0013] Furthermore, the heat pump air conditioning system has an energy storage heat output mode; When the heat pump air conditioning system is operating in the energy storage heat output mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, direct expansion photovoltaic thermal module, throttling device, thermal energy storage unit, indoor heat exchanger, four-way valve, gas-liquid separator, compressor; In the energy storage heat output mode, the heat storage module releases heat from the refrigerant to defrost the direct expansion photovoltaic thermal modules in the photovoltaic direct drive system.

[0014] Furthermore, the heat pump air conditioning system has an energy storage cold input mode; When the heat pump air conditioning system is operating in the energy storage cold input mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, outdoor heat exchanger, throttle valve, cold energy storage unit, direct expansion photovoltaic thermal module, indoor evaporator, four-way valve, gas-liquid separator, compressor; In the energy storage cold input mode, the cold energy storage module stores the cooling capacity of the refrigerant.

[0015] Furthermore, the heat pump air conditioning system has an energy storage cold output mode; When the heat pump air conditioning system is operating in the energy storage cold output mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, outdoor heat exchanger, cold energy storage unit, throttle valve, direct expansion photovoltaic thermal module, indoor evaporator, four-way valve, gas-liquid separator, compressor; In the energy storage cold input mode, the cold energy storage module uses cold energy to cool the direct expansion photovoltaic thermal modules in the photovoltaic direct drive system.

[0016] Furthermore, the photovoltaic direct drive system includes a multi-converter module, a photovoltaic module for providing electrical energy input to the multi-converter module, an electrochemical energy storage module, and a grid module; The photovoltaic direct drive system adjusts the power supply status of the photovoltaic module, electrochemical energy storage module, and grid module to the multi-element converter module based on the local irradiance received by the photovoltaic module, the real-time electricity price of the grid module, and the decision electricity price.

[0017] Furthermore, when the local irradiance is less than the threshold irradiance, the photovoltaic direct drive system controls the photovoltaic module to provide power to the multi-electrode converter module, and at the same time, according to the real-time electricity price and the decision electricity price, an electrochemical energy storage module or a grid module is set to assist the photovoltaic module in providing power. When the local irradiance equals the threshold irradiance, the photovoltaic direct drive system controls the photovoltaic module to provide power to the multi-element converter module independently; When the local irradiance is greater than the threshold irradiance, the photovoltaic direct drive system controls the photovoltaic module to provide power to the multi-electrode converter module, and at the same time, according to the real-time electricity price and the decision electricity price, the photovoltaic module is set to provide surplus power to the electrochemical energy storage module or the grid module. When the local irradiance is zero and the real-time electricity price is greater than the decision price, the photovoltaic direct drive system controls the electrochemical energy storage module to provide power to the multi-element converter module independently. When the local irradiance is zero and the real-time electricity price is less than the decision price, the photovoltaic direct drive system controls the grid module to provide power to the multi-element converter module independently.

[0018] Furthermore, when the local irradiance is less than the threshold irradiance and the real-time electricity price is greater than the decision electricity price, the photovoltaic direct drive system controls the electrochemical energy storage module to assist the photovoltaic module in providing electricity; When the local irradiance is less than the threshold irradiance and the real-time electricity price is less than the decision electricity price, the photovoltaic direct drive system controls the grid module to assist the photovoltaic module in providing power. When the local irradiance is greater than the threshold irradiance and the real-time electricity price is greater than the decision price, the photovoltaic direct drive system controls the photovoltaic module to supply the surplus power to the grid module. When the local irradiance is greater than the threshold irradiance and the real-time electricity price is less than the decision price, the photovoltaic direct drive system controls the photovoltaic module to provide surplus electricity to the electrochemical energy storage module.

[0019] Furthermore, the photovoltaic direct drive system is equipped with multiple switching switches, which can adjust the power supply status of the photovoltaic module, electrochemical energy storage module, and grid module to the multi-element converter module; The switching system includes an eleventh switch connected between the photovoltaic module and the electrochemical energy storage module, a twelfth switch connected between the photovoltaic module and the grid module, a thirteenth switch connected between the electrochemical energy storage module and the multi-element converter module, and a fourteenth switch connected between the grid module and the multi-element converter module.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: This invention has two systems: a photovoltaic direct-drive system and a heat pump air conditioning system. The photovoltaic direct-drive system has a photovoltaic module, an electrochemical energy storage module, and a grid module. By utilizing the power supply from the photovoltaic module, the electrochemical energy storage module, and the grid module, the energy utilization efficiency is maximized. Heat pump air conditioning systems consist of thermal energy storage modules and cold energy storage modules. The thermal energy storage module efficiently utilizes the heat in the refrigerant, preventing adverse user experience issues such as cold air blowing from the indoor heat exchanger during defrosting. It also avoids the negative impact of frost formation on the surface of direct-expansion photovoltaic thermal modules on power generation efficiency, thus increasing total energy output. The cold energy storage module efficiently utilizes the cooling capacity of the refrigerant, solving the problem of the condenser failing to cool the refrigerant to the target temperature in high-temperature environments. This reduces the compressor inlet temperature in high-temperature conditions, preventing unreliable compressor operation and low efficiency caused by excessively high compressor inlet temperatures, thereby improving the operating efficiency of the heat pump air conditioning system and enhancing energy utilization. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the photovoltaic-thermal energy storage flexible and efficient energy utilization system proposed in this invention; Figure 2 This is a schematic diagram of the structure of the heat pump air conditioning system in this invention; Figure 3 This is the control logic diagram of the working mode of the photovoltaic direct drive system in this invention; Figure 4 This is a schematic diagram showing the refrigerant flow path in the heat pump air conditioning system of the present invention under the energy storage heat input mode; Figure 5 This is a schematic diagram showing the refrigerant flow path in the heat pump air conditioning system of the present invention under the energy storage heat output mode; Figure 6 This is a schematic diagram showing the refrigerant flow path in the heat pump air conditioning system of the present invention under the energy storage cold input mode; Figure 7 This is a schematic diagram showing the refrigerant flow path in the energy storage cold output mode of the heat pump air conditioning system in this invention; Among them, 11 is a photovoltaic module, 12 is an electrochemical energy storage module, 13 is a grid module, 14 is a photovoltaic direct drive module, 15 is a multi-element converter module, 16 is a heat pump air conditioner, 17 is a cold energy storage module, 18 is a thermal energy storage module, 21 is an indoor heat exchanger, 22 is a gas-liquid separator, 23 is a four-way valve, 24 is a compressor, 25 is a direct expansion photovoltaic thermal module, 26 is an outdoor heat exchanger, 27 is a cold energy storage unit, 28 is a thermal energy storage unit, and 29 is a throttling device; K11 is the eleventh switch, K12 is the twelfth switch, K13 is the thirteenth switch, K14 is the fourteenth switch, K21 is the twenty-first switch, K22 is the twenty-second switch, K23 is the twenty-third switch, K24 is the twenty-fourth switch, K25 is the twenty-fifth switch, K26 is the twenty-sixth switch, K27 is the twenty-seventh switch, K28 is the twenty-eighth switch, K29 is the twenty-ninth switch, K210 is the two hundred and first switch, K211 is the two hundred and first eleventh switch, and K212 is the two hundred and second twelfth switch. Detailed Implementation

[0023] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0025] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0026] Please see Figure 1 To address the problem of low energy utilization efficiency in existing technologies, this invention proposes a photovoltaic direct drive and photovoltaic thermal expansion-based photovoltaic thermal storage flexible high-efficiency energy utilization system, including a photovoltaic direct drive system and a heat pump air conditioning system. The photovoltaic direct drive system consists of a photovoltaic module 11 and a multi-electrode converter module 15, equipped with at least one of the following modules: an electrochemical energy storage module 12, a grid module 13, and a photovoltaic direct drive module 14. The heat pump air conditioning system consists of a heat pump air conditioner 16 equipped with a cold energy storage 17, or a heat pump air conditioner 16 equipped with a heat energy storage 18, or a heat pump air conditioner 16 equipped with both cold energy storage 17 and heat energy storage 18. The photovoltaic direct drive system maximizes energy utilization efficiency by utilizing the power supply from the photovoltaic module 11, the electrochemical energy storage module 12, and the grid module 13. The heat storage 18 in the heat pump air conditioning system can make reasonable use of the heat in the refrigerant, avoid adverse operating conditions such as cold air blowing from the indoor heat exchanger during the defrosting process of the heat pump air conditioning system, which affect the user experience, and at the same time avoid the adverse effects of frost on the surface of the photovoltaic thermal module 25 on power generation efficiency, thereby increasing the total energy output. The cold energy storage 17 can make reasonable use of the cooling capacity of the refrigerant, thereby solving the problem that the condenser cannot cool the refrigerant to the target temperature under high temperature conditions. It reduces the inlet temperature of the compressor under high temperature conditions, avoiding the problems of unreliable compressor operation and low operating efficiency caused by excessively high compressor inlet temperature. At the same time, it can also use the cooling capacity of the refrigerant to cool the direct expansion photovoltaic thermal module 25, avoiding the problem of reduced power generation efficiency of the direct expansion photovoltaic thermal module due to increased summer temperature, thus improving energy utilization.

[0027] The heat pump air conditioning system has an energy storage heat input mode; please refer to [link / reference]. Figure 4 When the heat pump air conditioning system is operating in the energy storage heat input mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor 24, four-way valve 23, indoor heat exchanger 21, heat storage unit 28, throttling device 29, direct expansion photovoltaic thermal module 25, four-way valve 23, gas-liquid separator 22, compressor 24. The refrigerant flow is adjusted by regulating the switches. At this time, the 22nd switch K22, the 26th switch K26, and the 27th switch K27 are turned on, and all other switches are turned off.

[0028] As can be seen from the above refrigerant flow direction, when the ambient temperature is below 0℃ and it is in heating mode, the high-pressure refrigerant at the outlet of the indoor heat exchanger 21 will flow through the thermal energy storage unit 28 (corresponding to the thermal energy storage 18). At this time, the thermal energy storage unit 28 can exchange heat with the refrigerant, thereby storing the heat in the refrigerant. Furthermore, the heat pump air conditioning system has an energy storage heat output mode; please refer to [link / reference]. Figure 5 When the heat pump air conditioning system operates in energy storage heat output mode, the refrigerant adjustment process of the heat pump air conditioning system is as follows: Compressor 24, four-way valve 23, direct expansion photovoltaic thermal module 25, throttling device 29, thermal energy storage unit 28, indoor heat exchanger 21, four-way valve 23, gas-liquid separator 22, compressor 24.

[0029] At this time, the corresponding adjustment switches are: switch 22 K22, switch 26 K26 and switch 27 K27 are turned on, and all other switches are turned off. After this switch is turned on, the heat pump air conditioner 16 enters the heat pump heat storage operation mode. Compared with before, the direction of the four-way valve 23 has changed.

[0030] As can be seen from the refrigerant flow direction, when frost is detected on the surface of the direct expansion photovoltaic thermal module 25, the heat pump air conditioning system enters the heat pump defrosting mode. At this time, the refrigerant flows through the thermal energy storage unit 28. The thermal energy storage unit 28 can exchange heat when the refrigerant flows through it, thereby providing heat to heat the refrigerant and thus avoiding a significant reduction in the indoor ambient temperature.

[0031] The above-mentioned energy storage heat input mode and energy storage heat output mode can achieve the above effects: the heat storage 18 can make reasonable use of the heat in the refrigerant, avoid adverse operating conditions such as cold air blowing from the indoor heat exchanger during the defrosting process of the heat pump air conditioning system, which affect the user experience, and at the same time avoid the adverse effects of frost on the surface of the direct expansion photovoltaic thermal module on the power generation efficiency, thereby increasing the total energy output.

[0032] Furthermore, the heat pump air conditioning system has an energy storage cold input mode. When the heat pump air conditioning system is operating in the energy storage cold input mode, the refrigerant is regulated in the following order: compressor 24, four-way valve 23, outdoor heat exchanger 26, throttle valve 29, cold energy storage unit 27, direct expansion photovoltaic thermal module 25, indoor evaporator (not shown in the figure), four-way valve 23, gas-liquid separator 22, compressor 24. At this time, the corresponding adjustment switches are: switch 21 K21, switch 23 K23, switch 24 K24, switch 25 K25, switch 26 K28, switch 29 K29, switch 211 K211, and switch 212 are open, and the rest of the switches are closed. As can be seen from the above refrigerant flow direction, when the ambient temperature is greater than 20℃ and less than 35℃ and the heat pump air conditioning system is in cooling mode, the refrigerant will flow through the cold energy storage unit 27, at which time the cold energy storage unit 27 can store cold energy. Furthermore, the heat pump air conditioning system has an energy storage cold output mode. When the heat pump air conditioning system operates in the energy storage cold output mode, the following components are included: compressor 24, four-way valve 23, outdoor heat exchanger 26, cold energy storage unit 27, throttle valve 29, direct expansion photovoltaic thermal module 25, indoor evaporator (not shown in the figure), four-way valve 23, gas-liquid separator 22, and compressor 24. At this time, the corresponding adjustment switches are: switch 21 K21, switch 22 K22, switch 25 K25, switch 26 K28, switch 29 K29, switch 210, and switch 212 are open, and the rest of the switches are closed; As can be seen from the above refrigerant flow direction, when the ambient temperature is greater than 35°C, the refrigerant will flow through the cold energy storage unit 27. At this time, the refrigerant will exchange heat with the cold energy storage unit 27, thereby reducing the refrigerant temperature. The cold energy in the cold energy storage unit 27 is used to cool the refrigerant, thereby improving the cooling effect.

[0033] The aforementioned energy storage cold input mode and energy storage cold output mode can achieve the above effects: The cold energy storage 17 can make reasonable use of the cooling capacity of the refrigerant, thereby solving the problem that the condenser cannot cool the refrigerant to the target temperature under high temperature conditions. It reduces the inlet temperature of the compressor under high temperature conditions, avoiding the problems of unreliable compressor operation and low operating efficiency caused by excessively high compressor inlet temperature. At the same time, it can also use the cooling capacity of the refrigerant to cool the direct expansion photovoltaic thermal module 25, avoiding the problem of reduced power generation efficiency of the direct expansion photovoltaic thermal module due to increased summer temperature, thus improving energy utilization.

[0034] Please see Figure 3 In this invention, the photovoltaic direct-drive system allocates power to the photovoltaic module 11, the electrochemical energy storage module 12, and the grid module 13 based on the local irradiance received by the photovoltaic module and the real-time electricity price and decision electricity price of the grid module (here, the real-time electricity price and decision electricity price are also known as electricity price parameters). It mainly operates in five modes: When the local irradiance is less than the threshold irradiance, it is in the first working mode. At this time, the photovoltaic direct drive system controls the photovoltaic module 11 to provide power to the multi-electrode converter module 15. At the same time, according to the real-time electricity price and the decision electricity price, the electrochemical energy storage module 12 or the grid module 13 is set to assist the photovoltaic module 11 in providing power. When the local irradiance equals the threshold irradiance, it is in the second working mode. At this time, the photovoltaic direct drive system controls the photovoltaic module 11 to provide power to the multi-element converter module 15 alone. When the local irradiance is greater than the threshold irradiance, it is in the third working mode. At this time, the photovoltaic direct drive system controls the photovoltaic module 11 to provide power to the multi-electrode converter module 15. At the same time, according to the real-time electricity price and the decision electricity price, the photovoltaic module 11 is set to provide the surplus power to the electrochemical energy storage module 12 or the grid module 13. When the local irradiance is zero and the real-time electricity price is greater than the decision price, it is in the fourth working mode. At this time, the photovoltaic direct drive system controls the electrochemical energy storage module 12 to provide power to the multi-element converter module 15. When the local irradiance is zero and the real-time electricity price is less than the decision price, it is in the fifth working mode. At this time, the photovoltaic direct drive system control grid module 13 provides power to the multi-element converter module 15 independently.

[0035] The first working mode is during the day, but the local irradiance of the photovoltaic module 11 is low. Under this condition, the power generation of the photovoltaic module 11 itself is insufficient to power the load module. At this time, the electrochemical energy storage module 12 or the grid module 13 is required to assist in power supply. The specific module to assist in power supply is determined according to the electricity price parameter. If the current real-time electricity price is high, the electrochemical energy storage module 12 can be used to assist in power supply. Otherwise, the grid module 13 can be used to assist in power supply. That is, in this first mode, when the local irradiance is less than the threshold irradiance and the real-time electricity price is greater than the decision electricity price, the photovoltaic direct drive system controls the electrochemical energy storage module 12 to assist the photovoltaic module 11 in providing power. When the local irradiance is less than the threshold irradiance and the real-time electricity price is less than the decision price, the photovoltaic direct drive system control grid module 13 assists the photovoltaic module 11 in providing power. The second working mode is during the day and under the condition that the local irradiance of the photovoltaic module 11 is moderate. Under this condition, the power generation of the photovoltaic module 11 is just enough to power the load module. At this time, there is no need for the electrochemical energy storage module 12 or the grid module 13 to provide power. The photovoltaic module 11 supplies power to the load module alone through the multi-electrode converter module 15. The third working mode is during the day and under conditions where the local irradiance of photovoltaic module 11 is high. Under this condition, the photovoltaic module 11 generates a high amount of electricity, which can not only power the load module, but also has a surplus of electricity. To avoid wasting the surplus electricity, the surplus electricity generated by photovoltaic module 11 is used to power either electrochemical energy storage module 12 or grid module 13. Whether to power electrochemical energy storage module 12 or grid module 13 is determined by the electricity price parameter. If the current real-time electricity price is high, powering grid module 13 will yield higher economic benefits, and vice versa. That is, in this third working mode, when the local irradiance is greater than the threshold irradiance and the real-time electricity price is greater than the decision electricity price, the photovoltaic direct drive system controls the photovoltaic module 11 to provide the surplus power to the grid module 13. When the local irradiance is greater than the threshold irradiance and the real-time electricity price is less than the decision price, the photovoltaic direct drive system controls the photovoltaic module 11 to provide the surplus electricity to the electrochemical energy storage module 12.

[0036] Both the fourth and fifth working modes are nighttime. In these modes, the photovoltaic module 11 cannot generate electricity and can only be powered by either the electrochemical module 12 or the grid module 13. The choice between the electrochemical module 12 and the grid module 13 depends on the electricity price. If the current real-time electricity price is high, using the grid module 13 would result in higher costs, so the electrochemical module 12 would be used. Conversely, if the price is low, the grid module 13 would be used.

[0037] It should be noted that the threshold illuminance here may not be a specific value, but may be a range of values ​​within which the power generation of photovoltaic module 11 can just supply power to the load module.

[0038] Please see Figure 3 This is the working mode control logic diagram of the photovoltaic direct drive and photovoltaic thermal expansion-based photovoltaic thermal energy utilization system of the present invention. Figure 3In this context, 'a' represents the local illuminance, 'P' represents the real-time electricity price, 'a1' represents the threshold illuminance, and 'G' represents the decision-making electricity price. In this invention, after obtaining the local illuminance a and the real-time electricity price P, the first step is to determine a=0, which is used to determine whether the current environment is daytime or nighttime. If a=0, it means that the current environment is nighttime; if a>0, it means that the current environment is daytime (because illuminance cannot be negative, so there is no case where a<0). During the daytime, the photovoltaic module 11 can generate electricity and participate in power supply. At this time, it is necessary to determine whether the power generation of the photovoltaic module 11 is excessive or insufficient based on the local irradiance a and the threshold irradiance a1. When the local irradiance 'a' is less than the threshold irradiance 'a1', the power generation of the photovoltaic module 11 itself is insufficient to supply power to the load module. In this case, the electrochemical energy storage module 12 or the grid module 13 needs to provide assistance in supplying power, and the module enters the first working mode, i.e., the auxiliary power supply. Figure 3 Operating condition 1; When the local irradiance 'a' equals the threshold irradiance 'a1', the power generated by the photovoltaic module 11 is just enough to power the load module. At this time, the electrochemical energy storage module 12 or the grid module 13 does not need to provide auxiliary power supply, and the system enters the second working mode, i.e., the auxiliary power supply mode. Figure 3 Operating condition 2; When the local irradiance 'a' is greater than the threshold irradiance 'a1', the photovoltaic module 11 generates a higher amount of power under this condition. It can not only supply power to the load module but also has surplus power, thus entering the third operating mode, i.e., the auxiliary operating mode. Figure 3 Operating condition 3; At night, the photovoltaic module 11 cannot participate in power supply. At this time, it is necessary to determine whether the electrochemical energy storage module 12 or the grid module 13 will provide power supply based on the real-time electricity price P. When the real-time electricity price P is greater than the decision electricity price G, the cost of supplying power using the grid module 13 is too high, and power needs to be supplied through the electrochemical energy storage module 12. At this time, the fourth working mode is entered, namely, the auxiliary mode. Figure 3 Operating condition 4; Conversely, when the real-time electricity price P is less than the decision price G, the cost of using grid module 13 for power supply is lower, and the system enters the fifth operating mode, i.e., the attached mode. Figure 3 Operating condition 5.

[0039] Please see Figure 1 The connection method of the photovoltaic direct drive and photovoltaic thermal expansion-based photovoltaic thermal energy utilization system proposed in this invention is as follows: The output side of the photovoltaic module 11 is connected to the input side of the multi-electrode converter module 15, the input side of the electrochemical energy storage module 12, and the input side of the grid module 13, respectively, and a photovoltaic direct drive module 14 is connected between the output side of the photovoltaic module 11 and the input side of the multi-electrode converter module 15. An eleventh switch K11 is connected between the output side of the photovoltaic module 11 and the input side of the electrochemical energy storage module 12, and a twelfth switch K12 is connected between the output side of the photovoltaic module 11 and the input side of the grid module 13. The output side of the electrochemical energy storage module 12 is connected to the input side of the multi-element converter module 15, and a thirteenth switch K13 is connected between the output side of the electrochemical energy storage module 12 and the input side of the multi-element converter module 15. The output side of the power grid module 13 is connected to the input side of the multi-element converter module 15, and a fourteenth switch K14 is connected between the output side of the power grid module 13 and the input side of the multi-element converter module 15.

[0040] Switching between the five operating modes is achieved through the eleventh switch K11, the twelfth switch K12, the thirteenth switch K14, and the fifteenth switch K15. These switches are the same as the switching switches mentioned earlier. The specific switching logic is as follows: When the photovoltaic-thermal energy storage flexible high-efficiency energy utilization system is working in the first working mode, the photovoltaic-thermal energy storage flexible high-efficiency energy utilization system controls the thirteenth switch K13 or the fourteenth switch K14 to close according to the electricity price parameters; When the photovoltaic-thermal energy storage flexible high-efficiency energy utilization system is operating in the second working mode, the eleventh switch K11, the twelfth switch K12, the thirteenth switch K13, and the fourteenth switch K14 of the photovoltaic-thermal energy storage flexible high-efficiency energy utilization system are all not closed. When the photovoltaic-storage-thermal flexible high-efficiency energy utilization system is operating in the third working mode, the system controls the eleventh switch K11 or the twelfth switch K12 to close according to the electricity price parameters. When the photovoltaic-storage-thermal flexible high-efficiency energy utilization system is operating in the fourth working mode, the system controls the thirteenth switch K13 to close according to the electricity price parameters. When the photovoltaic-storage-thermal flexible high-efficiency energy utilization system is operating in the fifth working mode, the system controls the fourteenth switch K14 to close according to the electricity price parameters.

[0041] In the first operating mode, whether the photovoltaic module 11 is powered by the electrochemical energy storage module 12 or by the grid module 13 is determined by the relationship between the real-time electricity price and the decision-making electricity price. When the real-time electricity price is greater than the decision electricity price, the electrochemical energy storage module 12 assists the photovoltaic module 11 in supplying power. At this time, the thirteenth switch K13 is closed. When the real-time electricity price is lower than the decision electricity price, the power grid module 13 assists the photovoltaic module 11 in supplying power. At this time, the fourteenth switch K14 is closed. In the third operating mode, the photovoltaic module 11 will use its surplus electricity to supply power to the electrochemical energy storage module 12 or the grid module 13. The specific power supply relationship is determined by the relationship between the real-time electricity price and the decision-making electricity price. When the real-time electricity price is greater than the decision price, the photovoltaic module 11 will supply the surplus electricity to the grid module 13. At this time, the twelfth switch K12 will be closed. When the real-time electricity price is less than the decision price, the photovoltaic module 11 will use the surplus electricity to power the electrochemical module 12, and at this time, the eleventh switch K11 will be closed. Compared with the prior art, the present invention has at least the following beneficial effects: This invention has two systems: a photovoltaic direct-drive system and a heat pump air conditioning system. The photovoltaic direct-drive system includes a photovoltaic module, an electrochemical energy storage module, and a power grid module. By utilizing the power supply from the photovoltaic module, the electrochemical energy storage module, and the power grid module, the energy utilization efficiency is maximized. Heat pump air conditioning systems consist of thermal energy storage modules and cold energy storage modules. The thermal energy storage module efficiently utilizes the heat in the refrigerant, preventing adverse user experience issues such as cold air blowing from the indoor heat exchanger during defrosting. It also avoids the negative impact of frost formation on the surface of direct-expansion photovoltaic thermal modules on power generation efficiency, thus increasing total energy output. The cold energy storage module efficiently utilizes the cooling capacity of the refrigerant, solving the problem of the condenser failing to cool the refrigerant to the target temperature in high-temperature environments. This reduces the compressor inlet temperature in high-temperature conditions, preventing unreliable compressor operation and low efficiency caused by excessively high compressor inlet temperatures, thereby improving the operating efficiency of the heat pump air conditioning system and enhancing energy utilization.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic-thermal energy storage system for flexible and efficient energy utilization, characterized in that, Includes a heat pump air conditioning system and a photovoltaic system for supplying power to the heat pump air conditioning system; The heat pump air conditioning system has at least a thermal energy storage module and a cold energy storage module. The thermal energy storage module can store heat in the refrigerant in the heat storage mode and release the heat in the refrigerant in the defrost mode to defrost the photovoltaic thermal components in the photovoltaic system. The cold energy storage module can store the cold energy in the refrigerant in a low-temperature environment and use the cold energy to cool the photovoltaic thermal components in the photovoltaic system in a high-temperature environment. The heat pump air conditioning system has an energy storage cold input mode; When the heat pump air conditioning system is operating in the energy storage cold input mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, outdoor heat exchanger, throttle valve, cold energy storage unit, photovoltaic thermal module, indoor evaporator, four-way valve, gas-liquid separator, compressor; In the energy storage cold input mode, the cold energy storage module stores the cooling capacity of the refrigerant; The heat pump air conditioning system has an energy storage cold output mode; When the heat pump air conditioning system is operating in the energy storage cold output mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, outdoor heat exchanger, cold energy storage unit, throttle valve, photovoltaic thermal module, indoor evaporator, four-way valve, gas-liquid separator, compressor; In the energy storage cold input mode, the cold energy storage module uses cold energy to cool the photovoltaic thermal components in the photovoltaic system.

2. The photovoltaic-thermal energy storage system according to claim 1, characterized in that, The heat pump air conditioning system has an energy storage heat input mode; When the heat pump air conditioning system is operating in the energy storage heat input mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, indoor heat exchanger, heat storage unit, throttling device, photovoltaic thermal module, four-way valve, gas-liquid separator, compressor; In the energy storage heat input mode, the heat storage module stores the heat in the refrigerant.

3. The photovoltaic-thermal energy storage system according to claim 1, characterized in that, The heat pump air conditioning system has an energy storage heat output mode; When the heat pump air conditioning system is operating in the energy storage heat output mode, the refrigerant adjustment path of the heat pump air conditioning system is as follows: compressor, four-way valve, photovoltaic thermal module, throttling device, thermal energy storage unit, indoor heat exchanger, four-way valve, gas-liquid separator, compressor; In the energy storage heat output mode, the heat storage module releases heat from the refrigerant to defrost the photovoltaic thermal components in the photovoltaic system.

4. The photovoltaic-thermal energy storage system according to claim 1, characterized in that, The photovoltaic system includes a multi-converter module, a photovoltaic module for providing electrical energy input to the multi-converter module, an electrochemical energy storage module, and a grid module; The photovoltaic system adjusts the power supply status of the photovoltaic module, electrochemical energy storage module, and grid module to the multi-element converter module based on the local irradiance received by the photovoltaic module, the real-time electricity price of the grid module, and the decision electricity price.

5. The photovoltaic-thermal energy storage system according to claim 4, characterized in that, When the local irradiance is less than the threshold irradiance, the photovoltaic system controls the photovoltaic module to provide power to the multi-electrode converter module, and at the same time, sets up an electrochemical energy storage module or a grid module to assist the photovoltaic module in providing power according to the real-time electricity price and the decision electricity price. When the local irradiance equals the threshold irradiance, the photovoltaic system controls the photovoltaic module to provide power to the multi-element converter module independently; When the local irradiance is greater than the threshold irradiance, the photovoltaic system controls the photovoltaic module to provide power to the multi-electrode converter module, and at the same time, according to the real-time electricity price and the decision electricity price, the photovoltaic module is set to provide surplus power to the electrochemical energy storage module or the grid module. When the local irradiance is zero and the real-time electricity price is greater than the decision price, the photovoltaic system controls the electrochemical energy storage module to provide power to the multi-element converter module independently. When the local irradiance is zero and the real-time electricity price is less than the decision price, the photovoltaic system controls the grid module to provide power to the multi-converter module independently.

6. The photovoltaic-thermal energy storage system according to claim 5, characterized in that, When the local irradiance is less than the threshold irradiance and the real-time electricity price is greater than the decision electricity price, the photovoltaic system controls the electrochemical energy storage module to assist the photovoltaic module in providing electricity. When the local irradiance is less than the threshold irradiance and the real-time electricity price is less than the decision electricity price, the photovoltaic system controls the grid module to assist the photovoltaic module in providing electricity. When the local irradiance is greater than the threshold irradiance and the real-time electricity price is greater than the decision electricity price, the photovoltaic system controls the photovoltaic module to provide surplus electricity to the grid module; When the local irradiance is greater than the threshold irradiance and the real-time electricity price is less than the decision price, the photovoltaic system controls the photovoltaic module to provide surplus electricity to the electrochemical energy storage module.

7. The photovoltaic-thermal energy storage system according to claim 5, characterized in that, The photovoltaic system is equipped with multiple switching switches, which can adjust the power supply status of the photovoltaic module, electrochemical energy storage module, and grid module to the multi-element converter module; The switching system includes an eleventh switch connected between the photovoltaic module and the electrochemical energy storage module, a twelfth switch connected between the photovoltaic module and the grid module, a thirteenth switch connected between the electrochemical energy storage module and the multi-element converter module, and a fourteenth switch connected between the grid module and the multi-element converter module.

8. A refrigeration device, characterized in that, The refrigeration equipment has a photovoltaic thermal energy storage system as described in any one of claims 1 to 6.

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