A photovoltaic photo-thermal heat pump system, a control method thereof and an air conditioning system

Abstract

The application discloses a photovoltaic photo-thermal heat pump system and a control method thereof and an air conditioning system. The photovoltaic photo-thermal heat pump system comprises a main refrigerant flow path provided with a compressor, a first branch path connected with the main refrigerant flow path and provided with a photovoltaic photo-thermal assembly, and a second branch path connected with the main refrigerant flow path and provided with a first heat exchanger. A first regulating valve is arranged at the connection of the main refrigerant flow path and the first branch path and the second branch path, and the first regulating valve can distribute the proportion of refrigerant in the main refrigerant flow path flowing into the first branch path and the second branch path. Compared with the prior art, the application proposes a system and a control method in which a heat pump system is connected in parallel with a photovoltaic photo-thermal assembly, a refrigerant pump is used in cooperation with a regulating valve to reduce the power consumption of the compressor under various working conditions, and the working point of the photovoltaic photo-thermal heat pump system is adjusted by comparing the power consumption increase of the compressor and the total gain of the photovoltaic photo-thermal heat pump system, so that the optimal energy efficiency working point is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic power generation, and particularly to a photovoltaic and photo-thermal heat pump system, a control method thereof and an air conditioning system. BACKGROUND

[0002] The photovoltaic and photo-thermal heat pump system can utilize both photovoltaic (electric energy) and photo-thermal (thermal energy) solar energy. Due to the temperature characteristics of the crystalline silicon photovoltaic and photo-thermal component, the power generation efficiency of the crystalline silicon component under high temperature is often lower than the test result under the standard state, and the high temperature also affects the service life of the photovoltaic cell. The photovoltaic and photo-thermal component can currently take away and utilize the waste heat of the photovoltaic and photo-thermal component while generating electricity. The basic principle of the photovoltaic and photo-thermal heat pump system is to use the heat generated in the photovoltaic power generation process to improve the energy efficiency of the heat pump system or achieve the purpose of energy saving and carbon reduction.

[0003] The current photovoltaic and photo-thermal component includes two types according to the structure or the type of circulating working medium: one is that the refrigerant directly flows through the photovoltaic and photo-thermal component and takes away the heat, and this type includes common structures such as direct expansion type and tube plate type; the other is that the cooling liquid flows through the photovoltaic and photo-thermal component and takes away the heat to a heat exchanger, and the other side of the heat exchanger is connected to the refrigerant circulating system. Obviously, the former belongs to direct heat exchange, has higher efficiency and better compactness. However, there are also problems as follows.

[0004] The photovoltaic and photo-thermal component generally has a large planar area and a small thickness, so as to reduce the weight and volume, facilitate transportation and installation, and the photovoltaic and photo-thermal component is equivalent to adding a cold plate to the back of the conventional photovoltaic and photo-thermal component. Although the thickness is increased to a certain extent, it will not be significantly increased in the optimal design (because the use convenience of the conventional photovoltaic and photo-thermal component should be considered), which leads to a large resistance of the refrigerant or other working medium flowing through the photovoltaic and photo-thermal component (compared with the radiator of the conventional heat pump system), thereby resulting in a large parasitic power consumption, and finally making the system energy efficiency limited to improve, and even the energy efficiency decreases under extreme working conditions.

[0005] Therefore, how to design a photovoltaic and photo-thermal heat pump system, a control method thereof and an air conditioning system, which can solve the problem of low energy efficiency of the photovoltaic and photo-thermal heat pump system under some working conditions, is a technical problem to be solved in the industry. SUMMARY

[0006] In view of the problems in the prior art, the present application provides a photovoltaic and photo-thermal heat pump system, a control method thereof and an air conditioning system.

[0007] The technical scheme of the present application is to provide a photovoltaic and photo-thermal heat pump system, which comprises a main refrigerant flow path provided with a compressor, a first branch path connected with the main refrigerant flow path and provided with a photovoltaic and photo-thermal component, and a second branch path connected with the main refrigerant flow path and provided with a first heat exchanger.

[0008] A first regulating valve is arranged at the connection between the main refrigerant flow path and the first branch and the second branch, and the first regulating valve can distribute the proportion of refrigerant in the main refrigerant flow path flowing into the first branch and the second branch.

[0009] Further, a refrigerant pump arranged in the first branch and a second regulating valve arranged in the second branch are further included, the refrigerant pump can adjust the flow of refrigerant in the first branch, and the second regulating valve is used to adjust the resistance characteristic of the second branch.

[0010] Further, a first sensor and a second sensor arranged in the first branch are further included.

[0011] The first sensor is located at the input side of the photovoltaic-thermal component, and the second sensor is located at the output side of the photovoltaic-thermal component.

[0012] The first sensor and the second sensor are used to detect the physical state of the photovoltaic-thermal component.

[0013] Further, a third regulating valve arranged on the main refrigerant flow path is further included, the third regulating valve is connected with a refrigerant bypass, and the other side of the refrigerant bypass is connected to the first branch.

[0014] Further, when the photovoltaic-thermal heat pump system works in a heating mode, the photovoltaic-thermal component is used as an evaporator, and the first heat exchanger is arranged as a condenser.

[0015] When the photovoltaic-thermal heat pump system works in a cooling mode, the photovoltaic-thermal component is used as a condenser, and the first heat exchanger is arranged as an evaporator.

[0016] Further, the main refrigerant flow path is further provided with a first throttling valve, a second throttling valve, and a second heat exchanger.

[0017] The second heat exchanger serves as the input side of the main refrigerant flow path, and is used to receive the refrigerant flowing back from the first branch and the second branch.

[0018] The first throttling valve is arranged between the compressor and the first regulating valve, and the second throttling valve is arranged between the compressor and the second heat exchanger.

[0019] Further, the average temperature of the photovoltaic-thermal component satisfies a calculation model:

[0020] Tcell=f(Q,a,m1,m2,T1,T2,c,Tf,h)

[0021] Wherein, Q is irradiance, a is photoelectric conversion efficiency, T1 is refrigerant temperature detected by the first sensor, T2 is refrigerant temperature detected by the second sensor, m1 is refrigerant flow detected by the first sensor, m2 is refrigerant flow detected by the second sensor, c is specific heat capacity of the refrigerant, Tf is ambient temperature, h is comprehensive heat exchange coefficient, and Tcell is average temperature of the photovoltaic-thermal component.

[0022] The application further provides a control method of the photovoltaic-thermal heat pump system.

[0023] detecting the operation condition of the photovoltaic-thermal heat pump system;

[0024] when the photovoltaic-thermal heat pump system works in the heating mode, using the photovoltaic-thermal component as an evaporator and heating the refrigerant by using the waste heat of the photovoltaic-thermal component;

[0025] when the photovoltaic-thermal heat pump system works in the refrigeration mode, using the photovoltaic-thermal component as a condenser and cooling the refrigerant by using the radiation heat dissipation capacity of the photovoltaic-thermal component.

[0026] Further, the method further comprises:

[0027] when the photovoltaic-thermal component is in the power generation state, detecting the increase of the compressor power consumption and the total gain of the photovoltaic-thermal heat pump system;

[0028] judging whether the increase of the compressor power consumption is less than the total gain of the photovoltaic-thermal heat pump system;

[0029] when the judgment is yes, increasing the refrigerant flow of the first branch so that the increase of the compressor power consumption is equal to the total gain of the photovoltaic-thermal heat pump system.

[0030] The application further provides an air conditioning system, which has the photovoltaic-thermal heat pump system.

[0031] Compared with the prior art, the application has at least the following beneficial effects:

[0032] 1. The first regulating valve, the second regulating valve and the refrigerant pump are arranged, so that the refrigerant flow can be reasonably distributed, the refrigerant can flow through the photovoltaic-thermal component more when a large amount of heat absorption is needed, and the refrigerant can flow through the heat sink more when a large amount of heat dissipation is needed, so that the compressor power consumption can be reduced in some working conditions.

[0033] 2、The application also detects the compressor power consumption increase and the total gain of the photovoltaic-photothermal heat pump system, and adjusts the working point of the photovoltaic-photothermal heat pump system when the photovoltaic-photothermal assembly is in the power generation state, so that the compressor power consumption increase and the total gain of the photovoltaic-photothermal heat pump system are equal, through the control, the photovoltaic-photothermal heat pump system can work at the optimal energy efficiency working point, and the system energy efficiency optimization is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0035] Figure 1 The basic principle diagram of the photovoltaic-photothermal heat pump system of the present application;

[0036] Figure 2 The overall control flow chart of the photovoltaic-photothermal heat pump system of the present application;

[0037] Figure 3 The basic principle diagram of the photovoltaic-photothermal heat pump system in another embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0039] Therefore, one feature indicated in the specification will be used to explain one feature of one embodiment of the present application, and it is not implied that each embodiment of the present application must have the explained feature. In addition, it should be noted that the specification describes many features. Although some features can be combined together to show possible system designs, these features can also be used in other combinations which are not explicitly described. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0040] The principles and structures of the present application will be described in detail below in combination with the drawings and embodiments.

[0041] The photovoltaic photothermal assembly is generally large in planar area and small in thickness, thereby reducing weight and volume, facilitating transportation and installation, and the photovoltaic photothermal assembly is equivalent to adding a cold plate at the back of a conventional photovoltaic photothermal assembly. Although the thickness is increased to a certain extent, the thickness will not be significantly increased in the optimal design (because the use convenience of the conventional photovoltaic photothermal assembly is taken into account), which leads to a large resistance of the refrigerant or other working medium flowing through the photovoltaic photothermal assembly (compared with the radiator of the conventional heat pump system), thereby leading to a large parasitic power consumption, and finally the system energy efficiency is limited to increase, and even the energy efficiency is not increased but decreased in the extreme working condition.

[0042] In view of the above problems, the design idea of the present application is to connect the photovoltaic photothermal assembly and the heat exchanger in parallel, and distribute the refrigerant flowing through the photovoltaic photothermal assembly and the refrigerant flowing through the heat exchanger through an adjusting valve, so as to ensure that more refrigerant flows through the photovoltaic photothermal assembly when a large amount of heat absorption is required, and more refrigerant flows through the heat sink when a large amount of heat dissipation is required, so as to reduce the power consumption of the compressor in part working conditions.

[0043] Based on the above idea, the photovoltaic photothermal heat pump system provided by the present application comprises: a main refrigerant flow path provided with a compressor, a first branch path connected with the main refrigerant flow path and provided with a photovoltaic photothermal assembly, and a second branch path connected with the main refrigerant flow path and provided with a first heat exchanger;

[0044] The first adjusting valve is arranged at the connection of the main refrigerant flow path and the first branch path and the second branch path, and the first adjusting valve can distribute the proportion of the refrigerant in the main refrigerant flow path flowing into the first branch path and the second branch path.

[0045] Please refer to Figure 1 The main refrigerant flow path is a flow path provided with a throttle 1 (i.e. a first throttle valve), a compressor, a sensor 3 (i.e. a third sensor), a throttle 2 (i.e. a second throttle valve), and a heat exchanger 2 (i.e. a second heat exchanger);

[0046] The first branch path is a flow path provided with a refrigerant pump, a sensor 1 (i.e. a first sensor), a photovoltaic photothermal assembly, and a sensor 2 (i.e. a second sensor);

[0047] The second branch path is a flow path provided with a heat exchanger 1 (i.e. a first heat exchanger) and a valve 2 (i.e. a second adjusting valve);

[0048] The first adjusting valve is also a valve 1;

[0049] As can be seen, the first branch path and the second branch path are in a parallel relationship and are connected through the first adjusting valve;

[0050] Based on the connection relationship, the first regulating valve can realize the flow distribution of the total refrigerant flow, one of which enters the first branch, and the other enters the second branch, and the flow ratio of the two can be adjusted from 1:0 to 0:1 by adjusting the opening of the first regulating valve.

[0051] The purpose of the above distribution mode is to adjust the heat exchange characteristics of the first branch and the second branch. Although the photovoltaic-thermal component and the first heat exchanger are connected in parallel, the refrigerant flow through them is not fixed (i.e., the flow distribution ratio is not fixed). When a large amount of heat absorption is required, the refrigerant can flow through the first branch more, i.e., through the photovoltaic-thermal component for heat absorption. When a large amount of heat dissipation is required, the refrigerant can flow through the first heat exchanger more.

[0052] Based on the above distribution, the compressor power consumption can be reduced to a certain extent under some operating conditions.

[0053] Please refer to Figure 1 The application also includes a refrigerant pump arranged in the first branch and a second regulating valve arranged in the second branch. The refrigerant pump can adjust the flow of refrigerant in the first branch, and the second regulating valve is used to adjust the resistance characteristics of the second branch.

[0054] It should be noted that in the normal working process of the photovoltaic-thermal heat pump system, the MAP diagram reflected to the compressor is a region, not a line. Although the flow of refrigerant can be adjusted by adjusting the opening of the first regulating valve, the adjustment range is limited and cannot meet all operating conditions, especially the energy efficiency optimization under some operating conditions. Therefore, the application provides a refrigerant pump, which can realize the flow and distribution of refrigerant by consuming a small amount of energy, and sometimes even without starting the compressor.

[0055] The application uses a low-power refrigerant pump to realize precise adjustment of the flow and distribution of refrigerant under low-flow conditions, thereby optimizing energy consumption under the premise of meeting system requirements.

[0056] Please refer to Figure 1 The application also includes a first sensor and a second sensor arranged in the first branch.

[0057] The first sensor is located at the input side of the photovoltaic-thermal component, and the second sensor is located at the output side of the photovoltaic-thermal component.

[0058] The first sensor and the second sensor are used to detect the physical state of the photovoltaic-thermal component.

[0059] From Figure 1It can be seen that for the main refrigerant flow path and the first branch, the flow direction of the above refrigerant is in turn: compressor, first throttling valve, first regulating valve, refrigerant pump, first sensor, photovoltaic-thermal component, second regulating valve, second heat exchanger, second throttling valve, third sensor, compressor;

[0060] It can be seen that for the photovoltaic-thermal component, the side where the refrigerant flows in is the side where the first sensor is arranged, that is, the input side described above, and the side where the refrigerant flows out is the side where the second sensor is arranged, that is, the output side described above.

[0061] Among them, the first sensor and the second sensor can be a temperature and pressure integrated sensor, or a sensor formed by connecting a plurality of single sensors in parallel, and the specific design is based on cost control requirements;

[0062] After the first sensor and the second sensor are arranged, the physical state of the refrigerant entering and exiting the photovoltaic-thermal component can be detected in real time and accurately, including temperature, pressure, flow rate, etc.

[0063] After identifying the temperature, pressure, flow rate, etc. physical state, the phase state of the refrigerant (gas state, liquid state, or two-phase flow state) can be determined, so that adverse working conditions can be identified and damage to the compressor or refrigerant pump caused by inappropriate phase state can be avoided.

[0064] In addition, since the photovoltaic-thermal component generally has a large heat exchange area, the blowout plate or other structure commonly used in refrigerant flow space may have a leakage situation. After the first sensor and the second sensor detect the flow rate difference or pressure difference between the input side and the output side of the photovoltaic-thermal component, whether the flow rate difference or pressure difference is abnormal (a certain pressure drop is set when the photovoltaic-thermal component is shipped, and if it exceeds the pressure drop, it indicates that there may be a leakage problem), the refrigerant flow path of the photovoltaic-thermal component can be reacted to improve the reliability of the system.

[0065] Please refer to Figure 3 The present application also includes a third regulating valve arranged on the main refrigerant flow path, and the third regulating valve is connected with a refrigerant bypass, and the other side of the refrigerant bypass is connected to the first branch.

[0066] The above design is the connection mode of another embodiment of the present application, compared with Figure 1 The connection mode, an additional refrigerant bypass and a third regulating valve connected with the refrigerant bypass are added in this embodiment, so that not all refrigerants need to flow through the compressor, which further widens the working range of the present application in several extreme working conditions.

[0067] For example, in case 1: heating cycle, the photovoltaic-thermal component acts as an evaporator (e.g. during the day when the sunlight irradiance is good), its performance is higher than the conventional evaporator of the air source heat pump, and when the heat demand of the photovoltaic-thermal heat pump system is less than the solar heat absorbed by the photovoltaic-thermal component;

[0068] In case 2: refrigeration cycle, the photovoltaic-thermal component acts as a condenser (e.g. at night when the radiation heat dissipation is strong), its performance is higher than the conventional condenser of the air source heat pump, and when the cold demand of the photovoltaic-thermal heat pump system is less than the external radiation heat dissipation of the photovoltaic-thermal component;

[0069] For the above-mentioned case 1 and case 2, the refrigerant can be directly distributed by the third adjusting valve after passing through the second throttling valve, so that a larger proportion or all of the refrigerant directly enters the refrigerant pump without passing through the compressor, which can further improve the energy efficiency of the photovoltaic-thermal heat pump system.

[0070] That is, as mentioned above, the working range of the present application in several extreme conditions is further widened.

[0071] Based on the above principle, it can be seen that the photovoltaic-thermal component can be used as an evaporator or a condenser. For example, in case 1, the photovoltaic-thermal component is used as an evaporator, which can supply heat through the solar energy absorbed by the photovoltaic-thermal component;

[0072] For example, in case 2, the photovoltaic-thermal component is used as a condenser, which can dissipate heat through the external radiation of the photovoltaic-thermal component.

[0073] Please refer to Figure 1 The first heat exchanger and the second heat exchanger can be evaporators or condensers, cooperating with the throttling valve and the compressor, and the second branch connected with the main refrigerant flow path forms a circuit which actually constitutes the four major components of the air conditioning system. Therefore, when the photovoltaic-thermal heat pump system works in heating mode, the photovoltaic-thermal component is used as an evaporator, and the first heat exchanger can be set as a condenser to cooperate with the refrigerant distribution of the first adjusting valve;

[0074] Similarly, when the photovoltaic-thermal heat pump system works in refrigeration mode, the photovoltaic-thermal component is used as a condenser, and the first heat exchanger can be set as an evaporator to cooperate with the refrigerant distribution of the first adjusting valve.

[0075] Specifically, the second branch and the main refrigerant flow path constitute the four major components of the air conditioning system, and can also independently perform refrigeration or heating cycle, and the main refrigerant flow path is further provided with a first throttling valve, a second throttling valve, and a second heat exchanger;

[0076] The specific connection mode is as follows:

[0077] The second heat exchanger is used as an input side of a main refrigerant flow path, and is used for receiving refrigerant backflow from the first branch and the second branch.

[0078] The first throttling valve is arranged between the compressor and the first regulating valve, and the second throttling valve is arranged between the compressor and the second heat exchanger.

[0079] The four components of the air conditioning system formed by the second branch include a compressor, which is used for compressing gaseous refrigerant into high-temperature and high-pressure liquid refrigerant under high temperature and high pressure.

[0080] The condenser is used for changing the high-temperature and high-pressure liquid refrigerant into room-temperature and high-pressure liquid refrigerant under room temperature and high pressure.

[0081] The evaporator is used for changing the room-temperature and high-pressure liquid refrigerant into low-temperature and low-pressure gaseous refrigerant.

[0082] The low-temperature and low-pressure gaseous refrigerant returns to the compressor to form a refrigeration cycle.

[0083] Further, the average temperature of the photovoltaic-photothermal component satisfies a calculation model:

[0084] Tcell=f(Q,a,m1,m2,T1,T2,c,Tf,h)

[0085] Wherein, Q is irradiance, a is photoelectric conversion efficiency, T1 is the refrigerant temperature detected by the first sensor, T2 is the refrigerant temperature detected by the second sensor, m1 is the refrigerant flow detected by the first sensor, m2 is the refrigerant flow detected by the second sensor, c is the specific heat capacity of the refrigerant, Tf is the ambient temperature, h is the comprehensive heat exchange coefficient, and Tcell is the average temperature of the photovoltaic-photothermal component.

[0086] Based on the above principle, the average temperature of the photovoltaic-photothermal component is a function of irradiance, environmental conditions and refrigerant heat dissipation. At the same time, the power generation of the photovoltaic-photothermal component is affected by the temperature of the photovoltaic-photothermal component, and presents a negative correlation.

[0087] Obviously, under high irradiance (for example, at noon), the temperature of the photovoltaic-photothermal component will rise. In order to ensure that the temperature of the photovoltaic-photothermal component does not rise too high to affect the power generation efficiency and service life, generally only the refrigerant flow can be increased to dissipate heat: that is, the refrigerant flow is increased (under the condition that the refrigerant temperature is unchanged), so the power consumption of the refrigerant pump and the compressor is increased.

[0088] At a certain working point, the working point of the photovoltaic-thermal heat pump system is fine-tuned (for example, the working temperature of the photovoltaic-thermal component is increased by 1℃), the increase dQ of the power consumption of the refrigerant pump and the compressor and the total gain dB of the photovoltaic-thermal heat pump system (mainly the power generation gain and the life extension gain) are detected, when dQ < dB, the working point of the system is adjusted in a certain step along the positive direction of the working point fine-tuning until dQ and dB are equivalent.

[0089] A certain threshold can also be set, and when the component temperature is not higher than a certain temperature, the existing working state is maintained unchanged.

[0090] Here, the working point of the system is adjusted in a certain step along the positive direction of the working point fine-tuning because when the increase of the power consumption of the compressor is less than the total gain of the photovoltaic-thermal heat pump system, that is, dQ < dB, it means that a little increase of the power consumption of the compressor can bring more than this part of the power consumption, so the system can be adjusted in the direction of increasing the power consumption of the compressor, thereby obtaining greater benefits.

[0091] On the contrary, when the increase of the power consumption of the compressor is greater than the total gain of the photovoltaic-thermal heat pump system, that is, dQ > dB, it is not appropriate to continue to adjust.

[0092] Based on the above principle, the application provides a control method of a photovoltaic-thermal heat pump system, which comprises the following steps:

[0093] Detecting the running condition of the photovoltaic-thermal heat pump system;

[0094] When the photovoltaic-thermal heat pump system works in a heating mode, the photovoltaic-thermal component is used as an evaporator, and the waste heat of the photovoltaic-thermal component is used to heat the refrigerant;

[0095] When the photovoltaic-thermal heat pump system works in a refrigeration mode, the photovoltaic-thermal component is used as a condenser, and the radiation heat dissipation capacity of the photovoltaic-thermal component is used to cool the refrigerant.

[0096] And further comprising:

[0097] When the photovoltaic-thermal component is in a power generation state, the increase of the power consumption of the compressor and the total gain of the photovoltaic-thermal heat pump system are detected;

[0098] Judging whether the increase of the power consumption of the compressor is less than the total gain of the photovoltaic-thermal heat pump system;

[0099] When the judgment is yes, the refrigerant flow of the first branch is increased so that the increase of the power consumption of the compressor is equal to the total gain of the photovoltaic-thermal heat pump system.

[0100] Please refer to Figure 2 which is the overall control flow chart of the photovoltaic-thermal heat pump system of the application, and the attached Figure 2In this context, "component" refers to the photovoltaic thermal component mentioned above, "dB" represents the total gain of the photovoltaic thermal heat pump system mentioned above, and "dQ" represents the increase in power consumption of the compressor mentioned above.

[0101] Should Figure 2 The flowchart corresponds to the control method of the photovoltaic thermal heat pump system mentioned above, which first determines whether the current photovoltaic thermal heat pump system is working in heating mode or cooling mode.

[0102] If it is in heating mode, the working principle is as follows: absorb and utilize the waste heat of the components as the evaporator of the refrigeration cycle to achieve high-efficiency heating, which is the same as the previous text "when the photovoltaic thermal heat pump system is working in heating mode, the photovoltaic thermal components are used as evaporators, and the waste heat of the photovoltaic thermal components is used to heat the refrigerant".

[0103] If it is in cooling mode, the working principle is as follows: the strong radiative heat dissipation capacity of the components is used as the condenser of the cooling cycle to achieve high-efficiency cooling, which is the same as the previous text: "When the photovoltaic thermal heat pump system is working in cooling mode, the photovoltaic thermal components are used as condensers, and the radiative heat dissipation capacity of the photovoltaic thermal components is used to cool the refrigerant."

[0104] Then, in heating mode, it is determined whether the module generates electricity. If it does not generate electricity, it indicates that the module has a good heat dissipation effect and is not suitable as an evaporator for heating cycle at night. Therefore, the flow rate of the branch where the module is located is maintained or reduced.

[0105] In cooling mode, determine whether the module generates electricity. If it does not generate electricity, it indicates that the module has a good heat dissipation effect and should be given priority as the condenser for the nighttime cooling cycle. However, since the pressure drop of the module is large, the relationship between dB and dQ still needs to be examined.

[0106] Whether in heating or cooling mode, when the photovoltaic thermal module is determined to be in power generation state, the module needs to be shielded. However, if the total gain caused by the decrease in module temperature is taken into account, the module branch flow rate should be adjusted and the relationship between dB and dQ should be examined.

[0107] Then determine whether dB>dQ, which is the "determine whether the increase in compressor power consumption is less than the total gain of the photovoltaic thermal heat pump system" mentioned above;

[0108] When the determination is yes, maintain the current level or reduce the refrigerant flow rate of the component branch;

[0109] If the determination is no, then the refrigerant flow rate of the branch where the component is located is further increased and the component temperature is reduced (it can remain unchanged when it is below the threshold), which is the "increase in the refrigerant flow rate of the first branch so that the increase in compressor power consumption is equal to the total gain of the photovoltaic thermal heat pump system" mentioned above.

[0110] In addition, if the photovoltaic photothermal heat pump system energy efficiency is mainly considered (without focusing on the total gain of the component itself), the flow of the refrigerant on the two branches also needs to be adjusted and distributed (still through the first adjusting valve and the refrigerant pump), the main factors are: 1, in the heating process, when the heat collection effect of the photovoltaic photothermal component is not enough to cover the loss of its pressure drop energy consumption, or 2, in the refrigeration process, when the heat dissipation effect of the photovoltaic photothermal component is not enough to cover the loss of its pressure drop energy consumption, the flow of the component refrigeration branch should be adjusted or reduced.

[0111] The gain brought by the heat collection effect in the heating process can be estimated by the air source heat pump heating cost under the same heating capacity, and similarly, the gain brought by the heat dissipation effect in the refrigeration process can be estimated by the air source heat pump refrigeration cost under the same heat dissipation capacity.

[0112] Based on the above design, the application also provides an air conditioning system with the above photovoltaic photothermal heat pump system.

[0113] In summary, compared with the prior art, the application has at least the following beneficial effects:

[0114] 1、The first adjusting valve, the second adjusting valve and the refrigerant pump are arranged to reasonably distribute the refrigerant flow, so that more refrigerant passes through the photovoltaic photothermal component when a large amount of heat absorption is needed, and more refrigerant flows through the heat sink when a large amount of heat dissipation is needed, thereby reducing the compressor energy consumption in part of the working conditions;

[0115] 2、The application also detects the compressor power consumption increase and the total gain of the photovoltaic photothermal heat pump system, and adjusts the working point of the photovoltaic photothermal heat pump system when the photovoltaic photothermal component is in the power generation state, so that the compressor power consumption increase and the total gain of the photovoltaic photothermal heat pump system are equal, through the control, the photovoltaic photothermal heat pump system can work at the optimal energy efficiency working point, and the system energy efficiency is optimized.

[0116] The above only describes the preferred embodiments of the application and should not be used to limit the application, any modification, equivalent replacement and improvement made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A photovoltaic photothermal heat pump system, characterized in that, The main refrigerant flow path provided with a compressor, a first branch connected with the main refrigerant flow path and provided with a photovoltaic-thermal component, and a second branch connected with the main refrigerant flow path and provided with a first heat exchanger; A first regulating valve is arranged at the connection of the main refrigerant flow path and the first branch and the second branch, and the first regulating valve can distribute the proportion of refrigerant in the main refrigerant flow path flowing into the first branch and the second branch; Further comprising a refrigerant pump arranged in the first branch and a second regulating valve arranged in the second branch, the refrigerant pump can adjust the flow of refrigerant in the first branch, and the second regulating valve is used to adjust the resistance characteristics of the second branch; Further comprising a third regulating valve arranged on the main refrigerant flow path, and the third regulating valve is connected with a refrigerant bypass, and the other side of the refrigerant bypass is connected to the first branch; When the photovoltaic-thermal heat pump system works in a heating mode, the photovoltaic-thermal component is used as an evaporator, and the first heat exchanger is arranged as a condenser; When the photovoltaic-thermal heat pump system works in a cooling mode, the photovoltaic-thermal component is used as a condenser, and the first heat exchanger is arranged as an evaporator.

2. The photovoltaic photothermal heat pump system of claim 1, wherein, Further comprising a first sensor and a second sensor arranged in the first branch; The first sensor is located at the input side of the photovoltaic-thermal component, and the second sensor is located at the output side of the photovoltaic-thermal component; The first sensor and the second sensor are used to detect the physical state of the photovoltaic-thermal component.

3. The photovoltaic photothermal heat pump system of claim 1, wherein, The main refrigerant flow path is further provided with a first throttling valve, a second throttling valve, and a second heat exchanger; The second heat exchanger is used as the input side of the main refrigerant flow path, and is used to receive the refrigerant backflowing from the first branch and the second branch; The first throttling valve is arranged between the compressor and the first regulating valve, and the second throttling valve is arranged between the compressor and the second heat exchanger.

4. The photovoltaic photothermal heat pump system of claim 2, wherein, The average temperature of the photovoltaic-thermal component satisfies a calculation model: Tcell = f(Q,a,m1,m2,T1,T2,c,Tf,h) Wherein, Q is irradiance, a is photoelectric conversion efficiency, T1 is the refrigerant temperature detected by the first sensor, T2 is the refrigerant temperature detected by the second sensor, m1 is the refrigerant flow detected by the first sensor, m2 is the refrigerant flow detected by the second sensor, c is the specific heat capacity of the refrigerant, Tf is the ambient temperature, h is the comprehensive heat exchange coefficient, and Tcell is the average temperature of the photovoltaic-thermal component.

5. A control method for a photovoltaic photothermal heat pump system according to any one of claims 1 to 4, characterized in that, Including: Detecting the operating condition of the photovoltaic-thermal heat pump system; When the photovoltaic-thermal heat pump system works in a heating mode, the photovoltaic-thermal component is used as an evaporator, and the waste heat of the photovoltaic-thermal component is used to heat the refrigerant; When the photovoltaic-thermal heat pump system works in a cooling mode, the photovoltaic-thermal component is used as a condenser, and the radiation heat dissipation capacity of the photovoltaic-thermal component is used to cool the refrigerant.

6. The control method of a photovoltaic photothermolysis pump system according to claim 5, wherein, Further comprising: When the photovoltaic-thermal component is in a power generation state, detecting the increase of compressor power consumption and the total gain of the photovoltaic-thermal heat pump system; determining whether the compressor power consumption increase is less than the total gain of the photovoltaic / thermal heat pump system; when the determination is positive, increasing the refrigerant flow of the first branch to make the compressor power consumption increase equal to the total gain of the photovoltaic / thermal heat pump system.

7. An air conditioning system characterized by comprising: The air conditioning system has the photovoltaic / thermal heat pump system as claimed in any one of claims 1 to 4.

Images