CN116447637A - Photovoltaic direct-driven direct-expansion solar heat pump cogeneration system and control method thereof - Google Patents

Abstract

The invention discloses a photovoltaic direct-driven direct-expansion solar heat pump cogeneration system and a control method thereof, wherein the system comprises a domestic hot water sub-supply system, an electric supply sub-system, a controller and a solar photovoltaic photo-thermal integrated component with a built-in metal heat conducting pipeline; the domestic hot water sub-supply system comprises a heat storage water tank and a domestic hot water tank; a heat exchange coil is arranged in the heat storage water tank; the electric supply subsystem comprises a solar photovoltaic energy storage colloid storage battery and a grid-connected photovoltaic inverse control integrated machine, wherein the grid-connected photovoltaic inverse control integrated machine is electrically connected with the solar photovoltaic energy storage colloid storage battery, the solar photovoltaic photo-thermal integrated assembly and the power grid. The control method comprises the following steps: and supplying electric energy according to the sequence of the load, the solar photovoltaic energy storage colloid storage battery and the power grid or calling the electric energy according to the sequence of the solar photovoltaic energy storage colloid storage battery and the power grid. The invention realizes the coordination of domestic hot water demand and photovoltaic panel heat dissipation demand in cold areas, and avoids the condition of energy waste.

Description

Photovoltaic direct-driven direct expansion solar heat pump combined heat and power system and its control method

technical field

The invention belongs to the technical field of photovoltaic photothermal integrated heat and power cogeneration, and in particular relates to a photovoltaic direct-driven direct expansion solar heat pump cogeneration system and a control method thereof.

Background technique

Traditional solar energy utilization is divided into two methods: photothermal conversion and photoelectric conversion, and both are separated into two devices and two sets of energy systems for energy supply. There are disadvantages such as low energy efficiency in energy utilization, complicated equipment installation, high cost and large footprint. A single photovoltaic power generation system only has a conversion efficiency of 10%-20%, and 80%-90% of the radiant energy is partially reflected back, and the rest is converted into heat energy, which increases the temperature of the battery and reduces the electrical output. Studies have shown that the photoelectric conversion efficiency of photovoltaic cells decreases by 3‰-5‰ for every 1°C increase on average. The integrated utilization of electric energy and thermal energy can be realized by adopting the new photovoltaic photothermal (PV/T) combined heat and power technology, in which the electric energy is output by photovoltaic power generation, and then the fluid channel on the back is used to absorb the heat from the photovoltaic panel to heat the building or provide Domestic hot water is a technology for comprehensive utilization of solar photovoltaic and light heat. According to the type of cooling fluid in the back channel, PV/T solar collectors can be divided into air type, hot water type, heat pipe type and refrigerant type, etc. Four categories.

At present, PV/T combined heat and power technology has made good progress in theoretical analysis, simulation research and experimental research, which can be suitable for household hot water, heating and other civil and industrial applications that require low-humidity heat sources. use.

However, there are more or less defects in the combined heat and power system built by PV/T photovoltaic solar thermal integration. For example, the combined heat and power system is difficult to coordinate the domestic hot water demand The combined heat and power system combined with thermal integrated panels and heat pumps does not take into account the operation strategy when the heat pump consumes more energy than heat produced when solar energy is insufficient, resulting in energy waste and the combined heat and power system designed for users with solar heating needs Defects such as the storage and utilization of summer heat that is abundant in solar energy but does not require heating are not considered, and these defects are not conducive to the vigorous promotion and use of combined heat and power systems.

Contents of the invention

The object of the present invention is to provide a photovoltaic direct-expansion solar heat pump combined heat and power system and its control method to solve the above-mentioned problems in the prior art.

In order to achieve the above object, the present invention adopts the following technical solutions:

On the one hand, the present invention provides a direct expansion solar heat pump combined heat and power system driven by photovoltaics, including a domestic hot water sub-supply system, an electricity supply sub-system, a controller, and a solar-photovoltaic-photothermal integrated system with built-in metal heat-conducting pipes. The domestic hot water sub-supply system includes a hot water storage tank and a domestic hot water tank, the water inlet of the hot water tank is connected with tap water through a first electromagnetic valve, and the upper end of the domestic hot water tank is provided with a water inlet, The water outlet of the hot water storage tank is connected with the water inlet of the domestic hot water tank through the second solenoid valve. The lower ends of the hot water storage tank and the domestic hot water tank are both provided with heat exchange ports. The heat exchange port of the domestic hot water tank is connected through the third electromagnetic valve; a heat exchange coil is arranged in the hot water storage tank, and the inlet of the heat exchange coil is connected with the outlet of the metal heat-conducting pipe through the first pipeline. The outlet of the heat exchange coil is connected to the inlet of the metal heat conduction pipe through the second pipeline, and the metal heat conduction pipe, the first pipeline, the heat exchange coil and the second pipeline are connected end to end to form a circular heat conduction pipeline, and the circular heat conduction pipe A thermal conductive agent is set in the road; the power supply subsystem includes a solar photovoltaic energy storage colloidal battery and an off-grid photovoltaic inverse control integrated machine, an off-grid photovoltaic inverse control integrated machine, a solar photovoltaic energy storage colloidal battery, a solar photovoltaic photothermal The integrated components are electrically connected to the grid;

The controller is used to control the operation of the controlled equipment in the domestic hot water sub-supply system and the electricity supply sub-system.

As a preferred technical solution in the present invention, a baffle is provided in the middle of the heat storage tank, and the baffle divides the inner space of the heat storage tank into an upper water storage chamber and a lower water storage chamber. The fourth electromagnetic valve of the upper water storage chamber and the lower water storage chamber; the water inlet and outlet of the hot water storage tank are connected to the upper water storage chamber, and the heat exchange port of the hot water storage tank is connected to the lower water storage chamber; The heat exchange coil is arranged in the upper water storage chamber.

As a preferred technical solution in the present invention, a fifth solenoid valve is provided on the first pipeline, and the fifth solenoid valve is electrically connected to the controller.

As a preferred technical solution in the present invention, a thermoelectric generator for supplying power to the fifth solenoid valve is arranged on the first pipeline, and the hot end surface of the thermoelectric generator is in close contact with the first pipeline.

As a preferred technical solution in the present invention, the second pipeline is provided with a sixth solenoid valve and a compressor, and both the sixth solenoid valve and the compressor are electrically connected to the controller.

As a preferred technical solution in the present invention, an electric heater is arranged in the domestic hot water tank, and the electric heater is electrically connected to the controller.

As a preferred technical solution in the present invention, both the hot water storage tank and the domestic hot water tank are provided with temperature sensors electrically connected to the controller.

As a preferred technical solution in the present invention, both the hot water storage tank and the domestic hot water tank are insulated tanks.

On the other hand, the present invention also provides a control method of a direct expansion solar heat pump combined heat and power system driven by photovoltaics, specifically as follows:

In the case of sufficient electricity generated by solar photovoltaic photothermal integrated components, the off-grid photovoltaic inverter control integrated machine is used to supply electric energy in the order of load, solar photovoltaic energy storage colloidal battery and power grid;

In the case of insufficient power generated by solar photovoltaic photothermal integrated components, use the off-grid photovoltaic inverter control integrated machine to transfer the insufficient power of the load according to the order of solar photovoltaic energy storage colloidal batteries and the grid;

Wherein, the load includes: the controller, the domestic hot water sub-supply system and the electrical equipment in the power supply sub-system, as well as other household appliances.

Beneficial effects: the present invention uses metal heat-conducting pipes to absorb and export the heat of the solar photovoltaic photothermal integrated components to cool down the solar photovoltaic photothermal integrated components, so that the conversion efficiency of the solar photovoltaic photothermal integrated components is higher; wherein, using The heat exchange coil conducts the heat of the heat-conducting agent in the metal heat-conducting pipe to the water in the water storage tank, realizing the cooling of the solar photovoltaic photothermal integrated components, and can also guide the water in the heat storage tank to the domestic heat. The water tank is used to meet the demand for domestic hot water, so as to realize the coordination between the domestic hot water demand in cold areas and the heat dissipation demand of photovoltaic panels. At the same time, when the third solenoid valve is opened or the second solenoid valve and the third solenoid valve are opened at the same time , can make the water in the hot water tank and the water in the domestic hot water tank conduct heat quickly, and then increase the water temperature in the domestic hot water tank to meet the supply requirements of hot water, and at the same time reduce the temperature in the hot water tank Water temperature, so that the water temperature in the hot water storage tank can better take away the heat of the solar photovoltaic photothermal integrated components, so as to achieve the effect of cooling.

The present invention also utilizes the off-grid photovoltaic inverter control integrated machine to be electrically connected with the solar photovoltaic energy storage colloidal battery, the solar photovoltaic photothermal integrated component and the power grid, and can use the solar photovoltaic energy storage colloidal battery to accumulate solar photovoltaic photothermal For the electric energy generated by the components, when the solar energy is insufficient and the energy consumption of the heat pump is greater than the heat production, the electric energy accumulated by the solar photovoltaic energy storage colloidal battery can be used first, and then the electric energy of the grid can be converted and used to avoid energy waste. The problem of heat storage and utilization in summer when heating is required.

Description of drawings

Fig. 1 is a system structure diagram of the present invention.

In the figure: 1- solar photovoltaic photothermal integrated components; 2- hot water storage tank; 3- domestic hot water tank; 4- first solenoid valve; 5- second solenoid valve; 6- third solenoid valve; 7- Heat exchange coil; 8-solar photovoltaic energy storage colloidal battery; 9-off-grid photovoltaic inverter control integrated machine; 10-fifth solenoid valve; 11-thermoelectric generator; 12-sixth solenoid valve; 13-compressor; 14 - Electric heater.

Detailed ways

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and the description of the embodiments or the prior art. Obviously, the following description about the structure of the accompanying drawings is only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention.

Example:

As shown in Figure 1, on the one hand, the present invention provides a direct expansion solar heat pump combined heat and power system driven by photovoltaics, including a domestic hot water sub-supply system, an electrical supply sub-system, a controller and a built-in metal heat-conducting pipe The solar photovoltaic photothermal integrated module 1 uses metal heat-conducting pipes to absorb and export the heat of the solar photovoltaic photothermal integrated module 1 to cool down the solar photovoltaic photothermal integrated module 1, so that the solar photovoltaic photothermal integrated module 1 The conversion efficiency is higher.

The domestic hot water sub-supply system includes a hot water storage tank 2 and a domestic hot water tank 3. The water inlet of the hot water storage tank 2 is connected with tap water through a first electromagnetic valve 4, so as to facilitate water injection into the hot water storage tank 2. It is used for cooling down the solar photovoltaic photothermal integrated module 1 and providing domestic hot water. The upper end of the domestic hot water tank 3 is provided with a water inlet, and the water outlet of the hot water storage tank 2 is connected with the domestic hot water The water inlets of the water tank 3 are connected to facilitate the introduction of hot water into the domestic hot water tank 3 according to the amount of water in the domestic hot water tank 3, so as to ensure that the water in the domestic hot water tank 3 can meet the needs of use. The lower end of the hot water tank 3 is provided with a heat exchange port, and the heat exchange port of the hot water storage tank 2 is connected with the heat exchange port of the domestic hot water tank 3 through the third solenoid valve 6. If the domestic hot water tank 3 The water has not been used for a long time, causing the water temperature in the domestic hot water tank 3 to drop, and when the water temperature in the hot water storage tank 2 is obviously higher than the water temperature in the domestic hot water tank 3, the second electromagnetic valve 5 and the third electromagnetic valve can be opened at the same time. Solenoid valve 6 makes the water in the hot water storage tank 2 and the water in the domestic hot water tank 3 conduct heat quickly, thereby increasing the water temperature in the domestic hot water tank 3 to meet the supply requirements of hot water and reduce the storage capacity. The water temperature in the hot water tank 2 enables the water temperature in the hot water storage tank 2 to better take away the heat of the solar photovoltaic photothermal integrated module 1 to achieve the effect of cooling; The heat coil 7, the inlet of the heat exchange coil 7 is connected with the outlet of the metal heat conduction pipe through the first pipeline, the outlet of the heat exchange coil 7 is connected with the inlet of the metal heat conduction pipe through the second pipeline, and the metal heat conduction pipe , the first pipeline, the heat exchange coil 7 and the second pipeline are connected end to end to form a circulation heat conduction pipeline, and a heat conduction agent is arranged in the circulation heat conduction pipeline, and then in the process of solar photovoltaic photothermal integrated module 1 absorbing solar energy , the thermal conductive agent can be used to cool down the solar photovoltaic photothermal integrated module 1, and then the water in the hot water storage tank 2 can be used to cool down the thermal conductive agent, and the thermal conductive agent can also heat the water in the hot water storage tank 2 , to facilitate the provision of domestic hot water in the later stage, and then realize the coordination of domestic hot water demand in cold areas and photovoltaic panel heat dissipation demand.

The power supply subsystem includes a solar photovoltaic energy storage colloidal battery 8 and an off-grid photovoltaic inverse control integrated machine 9, an off-grid photovoltaic inverse control integrated machine 9, a solar photovoltaic energy storage colloidal battery 8, and a solar photovoltaic photothermal integrated component 1 is electrically connected to the power grid. In normal times, the solar photovoltaic energy storage colloidal battery 8 can be used to store the electric energy generated by the solar photovoltaic photothermal integrated component 1. The electric energy stored in the colloidal battery 8 can then be converted and utilized into electricity from the grid to avoid energy waste, and at the same time solve the problem of heat storage and utilization in summer when solar energy is abundant but does not require heating;

The controller is used to control the operation of the controlled equipment in the domestic hot water sub-supply system and the electricity supply sub-system, so that the operation of the equipment is more intelligent and the utilization of energy is more efficient.

The present invention utilizes metal heat-conducting pipes to absorb and export the heat of the solar photovoltaic photothermal integrated assembly 1 to cool down the solar photovoltaic photothermal integrated assembly 1, so that the conversion efficiency of the solar photovoltaic photothermal integrated assembly 1 is higher; wherein, using The heat exchange coil 7 conducts the heat of the heat-conducting agent in the metal heat-conducting pipe to the water in the hot water storage tank 2 to realize the cooling of the solar-photovoltaic-photothermal integrated module 1 , and also transfer the water in the hot-storage tank 2 lead to the domestic hot water tank 3 to meet the demand for domestic hot water, and then realize the coordination of the domestic hot water demand in cold areas and the heat dissipation demand of photovoltaic panels. At the same time, when the third electromagnetic valve 6 is opened or the second electromagnetic valve is opened simultaneously The valve 5 and the third solenoid valve 6 can make the water in the hot water storage tank 2 and the water in the domestic hot water tank 3 conduct heat quickly, thereby increasing the water temperature in the domestic hot water tank 3 to meet the supply requirements of hot water At the same time, the water temperature in the hot water storage tank 2 can also be reduced, so that the water temperature in the hot water storage tank 2 can better take away the heat of the solar photovoltaic photothermal integrated module 1 to achieve the cooling effect.

The present invention also utilizes the off-grid photovoltaic inverter control integrated machine 9 to be electrically connected to the solar photovoltaic energy storage colloidal battery 8, the solar photovoltaic photothermal integrated module 1 and the power grid, and the solar photovoltaic energy storage colloidal battery 8 can be used to store solar photovoltaic power at ordinary times. The electric energy generated by the photothermal integrated component 1, when the energy consumption of the heat pump is greater than the heat production when the solar energy is insufficient, the electric energy stored in the solar photovoltaic energy storage colloidal battery 8 can be used first, and then the electric energy of the grid can be converted and used to avoid energy waste. At the same time, it solves the problem of heat storage and utilization in summer when solar energy is abundant but does not require heating.

As a preferred implementation in this embodiment, it needs to be further explained that a partition is provided in the middle of the heat storage tank 2, and the partition divides the internal space of the heat storage tank 2 into an upper water storage chamber and a lower storage chamber. In the water chamber, a fourth electromagnetic valve connecting the upper water storage chamber and the lower water storage chamber is arranged in the partition; the water inlet and the water outlet of the heat storage tank 2 are connected to the upper water storage chamber, and the The heat exchange port is connected to the lower water storage chamber; the heat exchange coil 7 is arranged in the upper water storage chamber. Under normal circumstances, the heat transfer agent in the heat exchange coil 7 exchanges heat with the water in the upper water storage chamber, which can To achieve higher heat exchange efficiency, and then when the demand for hot water is relatively large, the domestic hot water tank 3 can be supplied first to facilitate use, and when the water in the domestic hot water tank 3 has not been used for a long time, resulting in domestic hot water When the water temperature in the water tank 3 drops, and the water temperature in the hot water storage tank 2 is obviously higher than the water temperature in the domestic hot water tank 3, the second solenoid valve 5, the third solenoid valve 6 and the third solenoid valve can be opened simultaneously. , so that the water in the hot water storage tank 2 and the water in the domestic hot water tank 3 can quickly conduct heat, thereby increasing the water temperature in the domestic hot water tank 3 to meet the supply requirements of hot water, and at the same time reduce the temperature of the hot water storage tank. 2, so that the water temperature in the hot water storage tank 2 can better take away the heat of the solar-photovoltaic-photothermal integrated module 1, so as to achieve the cooling effect.

As a preferred technical solution in the present invention, the first pipeline is provided with a fifth solenoid valve 10, and the fifth solenoid valve 10 is electrically connected to the controller. When the temperature of the water in the hot water tank 2 is low, the fifth solenoid valve 10 can be closed to prevent the water in the hot water tank 2 from being reversely conducted to the solar photovoltaic photothermal integrated module 1 through the heat conducting agent. It should be noted that a temperature sensor may be provided on the circulating heat-conducting pipeline to facilitate detection of the temperature of the heat-conducting agent in the circulating heat-conducting pipeline.

As a preferred technical solution in the present invention, the first pipeline is provided with a thermoelectric generator 11 for supplying power to the fifth solenoid valve, and the hot end surface of the thermoelectric generator 11 is in close contact with the first pipeline, because solar photovoltaic When the photothermal integrated component 1 is working, the temperature in the first pipeline is generally higher than the outdoor temperature, so the thermoelectric generator 11 can be used to generate proper power to supply the operation of the fifth solenoid valve, thereby saving electric energy.

As a preferred technical solution in the present invention, the second pipeline is provided with a sixth solenoid valve 12 and a compressor 13, and the sixth solenoid valve 12 and compressor 13 are all electrically connected to the controller to ensure The heat-conducting agent forms a stable circulation under control, thereby enabling the heat conduction of the solar photovoltaic photothermal integrated module 1 to conduct heat efficiently at the initial stage of operation.

As a preferred technical solution in the present invention, the domestic hot water tank 3 is provided with an electric heater 14, the electric heater 14 is electrically connected to the controller, and the water temperature in the domestic hot water tank 3 does not meet the requirements for use. When preparing water again, the electric heater 14 can be turned on for heating to meet the requirements of hot water.

As a preferred technical solution in the present invention, both the hot water storage tank 2 and the domestic hot water tank 3 are provided with temperature sensors electrically connected to the controller to facilitate real-time monitoring of the hot water storage tank 2 and the domestic hot water tank 3, and then realize the circulation of water flow according to the change of water temperature.

As a preferred technical solution in the present invention, the hot water storage tank 2 and the domestic hot water tank 3 are both insulated tanks to avoid energy loss caused by heat dissipation.

On the other hand, the present invention also provides a control method of a direct expansion solar heat pump combined heat and power system driven by photovoltaics, specifically as follows:

In the case of sufficient electricity generated by solar photovoltaic photothermal integrated components, the off-grid photovoltaic inverter control integrated machine is used to supply electric energy in the order of load, solar photovoltaic energy storage colloidal battery and power grid;

In the case of insufficient power generated by solar photovoltaic photothermal integrated components, use the off-grid photovoltaic inverter control integrated machine to transfer the insufficient power of the load according to the order of solar photovoltaic energy storage colloidal batteries and the grid;

Wherein, the load includes: the controller, the domestic hot water sub-supply system and the electrical equipment in the power supply sub-system, and other household appliances. Other household appliances refer to some common appliances such as refrigerators and water heaters used in households. household appliances.

In the embodiment of the present invention, the solar photovoltaic photothermal integrated module is in the working state for a long time, and the generated direct current is converted into alternating current through the off-grid photovoltaic inverter control integrated machine, and the electric energy is given priority to such as compressors and electric auxiliary heaters. For electrical equipment and other household appliances, when there is surplus electricity, it is first stored in the solar photovoltaic energy storage colloidal battery. When the solar photovoltaic energy storage colloidal battery is fully charged, the surplus electricity will be uploaded to the grid. When the solar energy is insufficient, the electric energy in the solar photovoltaic energy storage colloidal battery is used first, and when it is insufficient, it is supplemented by the grid to ensure the stability of the power supply.

Finally, it should be noted that: the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. A direct expansion solar heat pump combined heat and power system driven by photovoltaics, characterized in that it includes a domestic hot water sub-supply system, an electricity supply sub-system, a controller, and a solar-photovoltaic-photothermal integration with built-in metal heat-conducting pipes component(1); The domestic hot water sub-supply system includes a hot water storage tank (2) and a domestic hot water tank (3). The upper end of the water tank (3) is provided with a water inlet, and the water outlet of the heat storage tank (2) is communicated with the water inlet of the domestic hot water tank (3) through the second electromagnetic valve (5), and the water storage tank (2) ) and the lower end of the domestic hot water tank (3) are provided with a heat exchange port, and the heat exchange port of the hot water storage tank (2) is connected with the heat exchange port of the domestic hot water tank (3) through the third solenoid valve (6) through; the heat storage tank (2) is provided with a heat exchange coil (7), the inlet of the heat exchange coil (7) is connected with the outlet of the metal heat conduction pipe through the first pipeline, and the heat exchange coil ( 7) The outlet of the outlet is connected to the inlet of the metal heat-conducting pipe through the second pipeline, and the metal heat-conducting pipeline, the first pipeline, the heat exchange coil (7) and the second pipeline are connected end to end to form a circular heat-conducting pipeline, and the circular heat conduction A heat conducting agent is arranged in the pipeline; The power supply subsystem includes a solar photovoltaic energy storage colloidal battery (8) and an off-grid photovoltaic inverse control integrated machine (9), an off-grid photovoltaic inverse control integrated machine (9) and a solar photovoltaic energy storage colloidal battery (8) , The integrated solar photovoltaic photothermal module (1) is electrically connected to the power grid; The controller is used to control the operation of the controlled equipment in the domestic hot water sub-supply system and the electricity supply sub-system. 2. The photovoltaic direct-driven direct expansion solar heat pump combined heat and power system according to claim 1, characterized in that a partition is arranged in the middle of the heat storage tank (2), and the partition divides the heat storage tank ( 2) The internal space is divided into an upper water storage chamber and a lower water storage chamber, and a fourth electromagnetic valve connecting the upper water storage chamber and the lower water storage chamber is arranged in the partition; the water inlet of the heat storage tank (2) and The water outlets are all connected to the upper water storage chamber, and the heat exchange port of the heat storage tank (2) is connected to the lower water storage chamber; the heat exchange coil (7) is arranged in the upper water storage chamber. 3. The photovoltaic direct-driven direct expansion solar heat pump combined heat and power system according to claim 1, characterized in that, the first pipeline is provided with a fifth solenoid valve (10), and the fifth solenoid valve (10) Electrically connected with the controller. 4. The photovoltaic direct-driven direct expansion solar heat pump cogeneration system according to claim 3, characterized in that, the first pipeline is provided with a thermoelectric generator (11) for supplying power to the fifth solenoid valve, The hot end face of the thermoelectric generator (11) is in close contact with the first pipeline. 5. The photovoltaic direct-driven direct expansion solar heat pump cogeneration system according to claim 1, characterized in that, the second pipeline is provided with a sixth solenoid valve (12) and a compressor (13), the second The six solenoid valves (12) and the compressor (13) are all electrically connected to the controller. 6. The direct-expansion solar heat pump combined heat and power system of photovoltaic direct drive according to claim 1 is characterized in that, an electric heater (14) is arranged in the domestic hot water tank (3), and the electric heater ( 14) It is electrically connected with the controller. 7. The direct expansion solar heat pump combined heat and power system of photovoltaic direct drive according to claim 1, characterized in that, both the hot water storage tank (2) and the domestic hot water tank (3) are provided with a control system The temperature sensor is electrically connected to the device. 8. The photovoltaic direct-driven direct expansion solar heat pump combined heat and power system according to claim 1, characterized in that the heat storage tank (2) and the domestic hot water tank (3) are both incubators. 9. A control method for a direct expansion solar heat pump combined heat and power system driven by photovoltaics, characterized in that, the details are as follows: In the case of sufficient electricity generated by solar photovoltaic photothermal integrated components, the off-grid photovoltaic inverter control integrated machine is used to supply electric energy in the order of load, solar photovoltaic energy storage colloidal battery and power grid; In the case of insufficient power generated by solar photovoltaic photothermal integrated components, use the off-grid photovoltaic inverter control integrated machine to transfer the insufficient power of the load according to the order of solar photovoltaic energy storage colloidal batteries and the grid; Wherein, the load includes: the controller, the domestic hot water sub-supply system and the electrical equipment in the power supply sub-system, as well as other household appliances.