A photovoltaic photo-thermal and ground source heat pump combined energy supply system

Abstract

The application discloses a photovoltaic light heat and ground source heat pump combined energy supply system, which comprises a ground heat coil heat exchanger, a photovoltaic heat collector, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a first circulating pipeline, a second circulating pipeline, a third circulating pipeline, a fourth circulating pipeline and a controller, wherein the first heat exchanger is connected with the ground heat coil heat exchanger through the first circulating pipeline, the second heat exchanger is connected with the photovoltaic heat collector through the second circulating pipeline, and the first heat exchanger, the second heat exchanger and the third heat exchanger are connected in series through the third circulating pipeline. The application has the beneficial effects that the excess heat can be collected for heating and the ground heat temperature can be increased. Through effective control strategies and reasonable regulation of the operation mode of the system, the system can maintain the efficient utilization of solar energy and ground heat energy and reduce energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to a combined energy supply system, in particular to a photovoltaic and photothermal combined with ground source heat pump energy supply system. BACKGROUND

[0002] At present, the ground source heat pump is a kind of high-efficiency energy-saving and environment-friendly air conditioning system using underground shallow geothermal resources for heating and cooling. The existing ground source heat pump system generally takes heat from the ground in winter and takes cold from the ground in summer. However, in the cold region dominated by heating demand, long-term operation of a single ground source heat pump can easily lead to soil cold accumulation. On the other hand, photovoltaic cells generate electricity under the irradiation of sunlight, and part of the sunlight is converted into heat, causing the temperature of the photovoltaic cells to rise, and the power generation efficiency of the photovoltaic cells gradually decreases with the increase of temperature. Especially in summer, the direct sunlight hits the photovoltaic cells, the temperature rises rapidly, and the power generation efficiency decreases sharply, and at the same time, a large amount of heat is not utilized, thereby making the comprehensive utilization rate of solar energy relatively low. In addition, due to the lack of effective control strategy, the traditional ground source heat pump system has low system efficiency. Therefore, a photovoltaic and photothermal combined with ground source heat pump energy supply system is proposed, which can combine the geothermal energy and the heat collected in the solar photovoltaic and photothermal system through a certain control strategy for building energy supply. SUMMARY

[0003] The main purpose of the present application is to solve the problem of soil thermal imbalance caused by long-term use of ground source heat pump in cold regions;

[0004] Another object of the present application is to use geothermal energy and heat collected in the solar photovoltaic and photothermal system together to improve the comprehensive utilization efficiency of solar energy;

[0005] In order to solve the above problems and achieve the above purposes, the present application provides a photovoltaic and photothermal combined with ground source heat pump energy supply system.

[0006] The photovoltaic and photothermal combined with ground source heat pump energy supply system provided by the present application comprises a geothermal coil heat exchanger, a photovoltaic heat collector, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a first circulating pipeline, a second circulating pipeline, a third circulating pipeline, a fourth circulating pipeline and a controller, wherein the first heat exchanger is connected in communication with the geothermal coil heat exchanger through the first circulating pipeline, the second heat exchanger is connected in communication with the photovoltaic heat collector through the second circulating pipeline, the first heat exchanger, the second heat exchanger and the third heat exchanger are connected in series through the third circulating pipeline, the third heat exchanger and the fourth heat exchanger are connected in communication through the fourth circulating pipeline, and the controller is connected with and controls the operation of the control valves and water pumps assembled on the first circulating pipeline, the second circulating pipeline, the third circulating pipeline and the fourth circulating pipeline.

[0007] The first branch pipe and the second branch pipe are connected between the first circulation pipeline and the second circulation pipeline, a first three-way valve is assembled at the connection of the first branch pipe and the first circulation pipeline, a second three-way valve is assembled at the connection of the first branch pipe and the second circulation pipeline, a third three-way valve is assembled at the connection of the second branch pipe and the first circulation pipeline, a fourth three-way valve is assembled at the connection of the second branch pipe and the second circulation pipeline, a first water pump is assembled on the first circulation pipeline between the first three-way valve and the ground heat exchanger, a second water pump is assembled on the second circulation pipeline between the fourth three-way valve and the photovoltaic heat collector, a first temperature sensor is assembled on the second circulation pipeline after the fourth three-way valve, a second temperature sensor is assembled on the photovoltaic heat collector, the first temperature sensor and the second temperature sensor are connected with the controller, the first temperature sensor and the second temperature sensor can transmit the collected data to the controller in real time, and the first three-way valve, the second three-way valve, the third three-way valve, the fourth three-way valve, the first water pump and the second water pump are connected with the controller and controlled by the controller.

[0008] The third branch pipe is connected to the third circulation pipeline at both ends of the first heat exchanger and the second heat exchanger connected in series on the third circulation pipeline, the fifth three-way valve and the sixth three-way valve are assembled at the connections of the upper and lower ends of the third branch pipe and the third circulation pipeline, respectively, the expansion throttling valve is assembled on the third circulation pipeline between the fifth three-way valve and the third heat exchanger, the two parallel bypass pipes are connected on the third circulation pipeline between the sixth three-way valve and the third heat exchanger, the first reversing valve and the second reversing valve are assembled at the connections of the two ends of the two bypass pipes and the third circulation pipeline, respectively, the compressor is assembled on the third circulation pipeline between the first reversing valve and the second reversing valve, the fourth branch pipe is assembled between the third circulation pipeline and the third branch pipe between the first heat exchanger and the second heat exchanger, the seventh three-way valve and the eighth three-way valve are assembled at the connections of the two ends of the fourth branch pipe and the third circulation pipeline and the third branch pipe, respectively, the first dryness detector is assembled on the third circulation pipeline between the first heat exchanger and the seventh three-way valve, the second dryness detector is assembled on the third circulation pipeline between the second heat exchanger and the sixth three-way valve, the first dryness detector and the second dryness detector are connected with the controller, the first dryness detector and the second dryness detector can transmit the collected data to the controller in real time, the controller is connected with the fifth three-way valve, the sixth three-way valve, the expansion throttling valve, the first reversing valve, the second reversing valve, the compressor, the seventh three-way valve and the eighth three-way valve, respectively, and controls the work of the fifth three-way valve, the sixth three-way valve, the expansion throttling valve, the first reversing valve, the second reversing valve, the compressor, the seventh three-way valve and the eighth three-way valve.

[0009] The fourth circulating pipeline is provided with a third water pump, and the fourth circulating pipeline is connected with a first water supplement tank through a transmission pipeline, the transmission pipeline between the first water supplement tank and the fourth circulating pipeline is provided with a first pressure sensor and a first water supplement pump, the first pressure sensor is connected with the controller, the first pressure sensor can transmit collected data to the controller in real time, and the controller is connected with the third water pump and the first water supplement pump and controls the working of the third water pump and the first water supplement pump.

[0010] The fourth heat exchanger is also connected with a fifth circulating pipeline, the fifth circulating pipeline is provided with two parallel fan coils through bypass pipelines, the fifth circulating pipeline is provided with a ninth three-way valve and a thirteenth three-way valve at the connection positions of the two ends of the two bypass pipelines, the fifth circulating pipeline between the ninth three-way valve and the fourth heat exchanger is provided with a fourth water pump, the fifth circulating pipeline between the thirteenth three-way valve and the fourth heat exchanger is provided with a fifth water pump, the fifth circulating pipeline is connected with a second water supplement tank through a transmission pipeline, the transmission pipeline between the second water supplement tank and the fifth circulating pipeline is provided with a second pressure sensor and a second water supplement pump, the second pressure sensor is connected with the controller, the second pressure sensor can transmit collected data to the controller in real time, and the controller is connected with the ninth three-way valve, the thirteenth three-way valve, the fourth water pump, the fifth water pump and the second water supplement pump and controls the working of the ninth three-way valve, the thirteenth three-way valve, the fourth water pump, the fifth water pump and the second water supplement pump.

[0011] The second circulating pipeline is connected with the fifth circulating pipeline through a fifth branch pipeline and a sixth branch pipeline, the fifth branch pipeline is provided with an eleventh three-way valve at the connection position with the second circulating pipeline, the fifth branch pipeline is provided with a twelfth three-way valve at the connection position with the fifth circulating pipeline, the sixth branch pipeline is provided with a tenth three-way valve at the connection position with the second circulating pipeline, the sixth branch pipeline is provided with a fourteenth three-way valve at the connection position with the fifth circulating pipeline, the fourth heat exchanger is connected with the fifth branch pipeline through a seventh branch pipeline, the seventh branch pipeline is provided with a fifteenth three-way valve at the connection position with the fifth branch pipeline, the fourth heat exchanger is connected with the sixth branch pipeline through an eighth branch pipeline, the eighth branch pipeline is provided with a sixteenth three-way valve at the connection position with the sixth branch pipeline, and the eighth branch pipeline is also provided with a sixth water pump.

[0012] The first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger are water tank type heat exchangers, the flowing medium in the water tank type heat exchangers is water, the first heat exchanger, the second heat exchanger and the third heat exchanger are all equipped with evaporators or condensers, the fourth heat exchanger is equipped with a heat exchange coil, the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger are all equipped with third temperature sensors, the third temperature sensors equipped on the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger are connected with the controller, and the third temperature sensors can transmit the collected data to the controller in real time.

[0013] The fourth heat exchanger is also equipped with a heater, the heater is connected with a battery, the battery provides power for the heater, the heater is connected with the controller and is controlled by the controller, and the battery is connected with the controller and provides power for the controller.

[0014] The battery is connected with the photovoltaic heat collector, an MPPT controller is equipped on the connecting line between the photovoltaic heat collector and the battery, the MPPT controller is a maximum power point tracking solar controller, the MPPT controller can detect the power generation voltage of the photovoltaic cell panel in the photovoltaic heat collector in real time, and track the highest voltage and current value, so that the photovoltaic cell panel outputs power at the maximum power to charge the battery, the battery is also connected with a power supply line, the battery is connected with the electric device in the system through the power supply line, the battery is also connected with the commercial power line through the line, an AC / DC bidirectional inverter and a bidirectional electric meter are sequentially equipped on the line connected with the commercial power line, the excess power in the battery can be transported into the commercial power line, and when the power in the battery is insufficient to supply power to the electric device in the system, the insufficient part of the power is provided by the commercial power line.

[0015] The above-mentioned geothermal coil heat exchanger, photovoltaic heat collector, first heat exchanger, second heat exchanger, third heat exchanger, fourth heat exchanger, first circulating pipeline, second circulating pipeline, third circulating pipeline, fourth circulating pipeline, controller, first three-way valve, second three-way valve, third three-way valve, fourth three-way valve, first water pump, second water pump, first temperature sensor, second temperature sensor, fifth three-way valve, sixth three-way valve, expansion throttle valve, first reversing valve, second reversing valve, compressor, seventh three-way valve, eighth three-way valve, first dryness detector, second dryness detector, third water pump, first pressure sensor, first water supplement pump, fifth circulating pipeline, fan coil, ninth three-way valve, thirteenth three-way valve, fourth water pump, fifth water pump, second pressure sensor, second water supplement pump, eleventh three-way valve, twelfth three-way valve, tenth three-way valve, fourteenth three-way valve, fifteenth three-way valve, sixteenth three-way valve, sixth water pump, third temperature sensor, heater, battery, MPPT controller, AC / DC bidirectional inverter and bidirectional electric meter are all assembled from existing devices, therefore, the specific model and specification are not described in detail.

[0016] The working principle of the present application is as follows:

[0017] The working principle of the photovoltaic light heat and ground source heat pump combined energy supply system provided by the present application is as follows:

[0018] Working condition one: in winter with light, photovoltaic heat is sufficient to meet the heating demand. The second temperature sensor detects that the photovoltaic heat collector is heated, and the controller starts the second water pump. Under the action of the second water pump, 7℃ low-temperature water enters the second circulating pipeline from the sixth branch pipe. The 7℃ low-temperature water in the second circulating pipeline takes away the heat generated by the photovoltaic heat collector. The second temperature sensor detects that the water temperature rises to 45℃ and opens the eleventh three-way valve through the action of the controller. The 45℃ hot water enters the fifth branch pipe under the action of the eleventh three-way valve. When the useful heat is required, the first temperature sensor detects that the water temperature reaches 45℃, and the 45℃ hot water enters the fifth circulating pipeline through the fifth branch pipe to directly heat the fan coil under the action of the eleventh three-way valve and the twelfth three-way valve. After the heating is completed, the water temperature decreases to about 35℃, and then the water is guided back to the second circulating pipeline through the sixth branch pipe under the action of the fifth water pump and the fourteenth three-way valve. The cooled water is heated through the second circulating pipeline and the photovoltaic heat collector, and the water temperature rises to 45℃, and then enters the next cycle under the action of the second water pump. When the room does not need heating, the 45℃ hot water generated by the photovoltaic heat collector can be guided to the fourth heat exchanger for heat storage through the seventh branch pipe under the action of the fifteenth three-way valve, so as to be used by the user. After the heat storage is completed, the water is guided back to the second circulating pipeline through the eighth branch pipe and the sixth branch pipe under the action of the sixth water pump and the sixteenth three-way valve. The cooled water absorbs the heat of the photovoltaic heat collector through the second circulating pipeline, and the water temperature rises to 45℃, and then enters the next cycle under the action of the second water pump. When the room does not need heating and the heat in the fourth heat exchanger is full, the controller controls the first three-way valve, the second three-way valve, the third three-way valve and the fourth three-way valve to open. The 45℃ hot water generated by the photovoltaic heat collector can be guided to the ground heat disc heat exchanger for heat storage through the second branch pipe under the action of the fourth three-way valve. The water after the heat storage enters the second circulating pipeline through the first branch pipe under the action of the first water pump, the first three-way valve and the second three-way valve. The cooled water absorbs the heat of the photovoltaic heat collector through the second circulating pipeline, and the water temperature rises to 45℃, and then enters the next cycle under the action of the second water pump. When the system is short of water, the second pressure sensor detects that the pressure is lower than the set value, and the controller starts the second water supplement pump to pump the water in the second water supplement tank for water supplement;

[0019] Case two: winter with light, photovoltaic heat is not enough to meet the heating demand. The second temperature sensor detects the photovoltaic collector temperature rise, the controller controls the second water pump starts. Under the action of the second water pump, 7 ℃ low temperature water through the second circulating pipeline to take away the heat generated by photovoltaic light heat collector, water temperature rises, under the action of the eleventh three-way valve through the second circulating pipeline into the second heat exchanger. At this time, the third circulating pipeline starts heat pump circulation mode, the second heat exchanger evaporator in low temperature liquid state working medium absorbs the heat of the second heat exchanger water to evaporate, after the completion of the evaporation of low pressure gas state working medium through the third circulating pipeline into the compressor, after the compressor pressure rise into high pressure gas state working medium into the third heat exchanger in the condenser, high pressure gas state working medium in the third heat exchanger condenser heat to the third heat exchanger water to complete the condensation of liquid, after the completion of the condensation of high pressure liquid working medium through the expansion throttle valve into low pressure liquid working medium, the controller controls the fifth three-way valve, the eighth three-way valve and the seventh three-way valve open, low pressure liquid working medium under the action of the fifth three-way valve, the eighth three-way valve and the seventh three-way valve through the third branch and the fourth branch into the third circulating pipeline, and then through the third circulating pipeline returns to the second heat exchanger in the evaporator to continue to evaporate heat. In this case, the temperature of the working medium in the second heat exchanger evaporator is 5 ℃, the temperature of the working medium in the third heat exchanger condenser is 60 ℃, the temperature of the water in the second heat exchanger is reduced to 7 ℃ after heat absorption, and the temperature of the water in the third heat exchanger is increased from 20 ℃ to 50 ℃. When the second dryness detector detects that the working medium in the evaporator of the second heat exchanger is not completely evaporated, the first circulating pipeline is started to heat the system, the controller controls the first water pump to flow at low speed in the first circulating pipeline, and the 7 ℃ low temperature water enters the geothermal coil heat exchanger through the first circulating pipeline under the action of the first water pump, and the temperature rises to about 15 ℃ after heat exchange with the earth soil, and then enters the first heat exchanger. At this time, the controller controls the eighth three-way valve to close, the low temperature liquid working medium in the evaporator of the first heat exchanger absorbs the heat of the water in the first heat exchanger to evaporate, the first dryness detector detects that the working medium in the evaporator of the first heat exchanger is not completely evaporated, and the liquid working medium which is not completely evaporated enters the evaporator of the second heat exchanger through the third circulating pipeline to continue to absorb heat. At this time, the second dryness detector detects that the working medium in the second heat exchanger has completely evaporated, if the working medium in the second heat exchanger has not completely evaporated, increase the power of the first water pump to make the water in the first circulating pipeline flow faster, the low pressure gas state working medium after the completion of the evaporation of heat absorption through the third circulating pipeline into the compressor, after the compressor pressure rise into high pressure gas state working medium into the third heat exchanger in the condenser, high pressure gas state working medium in the third heat exchanger condenser heat to the third heat exchanger water to complete the condensation of liquid, after the completion of the condensation of high pressure liquid working medium through the expansion throttle valve into low pressure liquid working medium after the third circulating pipeline returns to the first heat exchanger in the evaporator to continue to evaporate heat.In this condition, the temperature of the working medium in the evaporator of the first heat exchanger is 5℃, the temperature of the working medium in the evaporator of the second heat exchanger is 10℃, the temperature of the working medium in the condenser of the third heat exchanger is 60℃, the temperature of the water in the first heat exchanger and the second heat exchanger is reduced to 7℃ after absorbing heat, and the temperature of the water in the third heat exchanger is increased to 50℃. The heat stored in the third heat exchanger is transferred to the fourth heat exchanger through the fourth circulating pipeline under the action of the third water pump. When the user needs heat, the third temperature sensor detects that the water temperature in the fourth heat exchanger reaches about 45℃, and the water enters the fan coil through the fifth circulating pipeline under the action of the fourth water pump to supply heat to the room. After the heating is completed, the water temperature is reduced to about 35℃, and then the water is guided back to the fourth heat exchanger by the fifth water pump to enter the next cycle. At the same time, the third temperature sensor detects that the water temperature in the first heat exchanger and the second heat exchanger is reduced to about 7℃. The cooled water in the first heat exchanger is heated by the geothermal coil heat exchanger through the first circulating pipeline, and then enters the next cycle under the action of the first water pump. The cooled water in the second heat exchanger is heated by the photovoltaic collector through the second circulating pipeline, and then enters the next cycle under the action of the second water pump. When the room does not need heating, the 50℃ hot water produced by the third heat exchanger is stored in the fourth heat exchanger through the fourth circulating pipeline under the action of the third water pump for the user to use. When the room does not need heating and the heat in the fourth heat exchanger is full, the controller controls the first three-way valve, the second three-way valve, the third three-way valve and the fourth three-way valve to open, and the hot water produced by the photovoltaic collector can be stored in the geothermal coil heat exchanger through the second branch pipe under the action of the fourth three-way valve. After the heat storage is completed, the cooled water enters the second circulating pipeline through the first branch pipe under the action of the first water pump, the first three-way valve and the second three-way valve, and then is heated by the photovoltaic collector through the second circulating pipeline, and then enters the next cycle under the action of the second water pump. When the third temperature sensor detects that the water temperature in the fourth heat exchanger does not reach the preset value of 45℃, the controller instructs the battery to supply power to the heater to heat the fourth heat exchanger. If the heating requirement is still not met, the city power supply line is introduced to provide power to the heater through the bidirectional watt-hour meter and the AC / DC bidirectional inverter to heat the fourth heat exchanger to the preset value of 45℃. When the water in the third heat exchanger is insufficient, the first pressure sensor detects that the pressure is lower than the set value, and the controller starts the first water supplement pump to pump water from the first water supplement tank for water supplement. When the system is short of water, the second pressure sensor detects that the pressure is lower than the set value, and the controller starts the second water supplement pump to pump water from the second water supplement tank for water supplement.

[0020] Case three: winter without light. The second temperature sensor does not detect the photovoltaic collector temperature rise, the second circulating pipeline stops running. Under the action of the first water pump, 7℃ low temperature water enters the geothermal coil heat exchanger from the first circulating pipeline, and the temperature rises to about 15℃ after heat exchange with the earth soil, and then enters the first heat exchanger. At this time, the third circulating pipeline starts the heat pump circulation mode, the controller controls the sixth, seventh and eighth three-way valves to open, and the low temperature liquid refrigerant in the evaporator of the first heat exchanger absorbs the heat of the water in the first heat exchanger to complete the evaporation process. At this time, the first dryness detector detects that the refrigerant in the evaporator of the first heat exchanger has completely evaporated. If the refrigerant in the evaporator of the first heat exchanger has not completely evaporated, increase the power of the first water pump to make the water in the first circulating pipeline flow faster. The low pressure gas state refrigerant after evaporation and heat absorption enters the compressor through the fourth branch pipe, the third branch pipe and the third circulating pipeline under the action of the sixth, seventh and eighth three-way valves, and becomes high pressure gas state refrigerant after being pressurized by the compressor. The high pressure gas state refrigerant enters the condenser in the third heat exchanger, and the high pressure gas state refrigerant releases heat in the condenser of the third heat exchanger to complete the condensation and liquefaction of the water in the third heat exchanger. The high pressure liquid refrigerant after condensation and liquefaction becomes low pressure liquid refrigerant after passing through the expansion valve, and returns to the evaporator in the first heat exchanger through the third circulating pipeline to continue evaporation and heat absorption. In this case, the temperature of the refrigerant in the evaporator of the first heat exchanger is 5℃, the temperature of the refrigerant in the condenser of the third heat exchanger is 60℃, the temperature of the water in the first heat exchanger decreases from 15℃ to 7℃, and the temperature of the water in the third heat exchanger increases from 20℃ to 50℃. The heat stored in the third heat exchanger is stored in the fourth heat exchanger through the fourth circulating pipeline under the action of the third water pump. When the heat is required, the third temperature sensor detects that the water temperature in the fourth heat exchanger reaches about 45℃, and then enters the fan coil through the fifth circulating pipeline under the action of the fourth water pump to heat the room. After heating, the water temperature decreases to about 35℃, and then returns to the fourth heat exchanger through the fifth water pump to enter the next cycle. At the same time, the third temperature sensor detects that the water temperature in the first heat exchanger decreases to about 7℃. The water in the first heat exchanger is heated by the geothermal coil heat exchanger through the first circulating pipeline, and then enters the next cycle under the action of the first water pump. When the room does not need heating, the 50℃ hot water produced by the third heat exchanger is stored in the fourth heat exchanger through the fourth circulating pipeline under the action of the third water pump, ready for use. When the third temperature sensor detects that the water temperature in the fourth heat exchanger does not reach the preset value of 45℃, the controller instructs the battery to supply power to the heater to heat the fourth heat exchanger. If the heating requirement is still not met, the mains power supply is introduced to provide power to the heater through the bidirectional watt-hour meter and AC / DC bidirectional inverter to heat the fourth heat exchanger to the preset value of 45℃.When the third heat exchanger is short of water, the first pressure sensor detects that the pressure is lower than the set value, and the controller starts the first water supplement pump to pump water in the first water supplement tank for water supplement; when the system is short of water, the second pressure sensor detects that the pressure is lower than the set value, and the controller starts the second water supplement pump to pump water in the second water supplement tank for water supplement.

[0021] Case four: summer conditions, the second temperature sensor does not detect photovoltaic heat collector temperature rise, the second circulating pipeline stop running. When the second temperature sensor detects photovoltaic heat collector temperature rise, the controller controls the first water pump, the second water pump, the first three-way valve, the second three-way valve, the third three-way valve and the fourth three-way valve open. Under the action of the first water pump, the second water pump, the first three-way valve and the second three-way valve, 15℃ cold water in the geothermal coil heat exchanger through the first circulating pipeline and the first branch pipe into the third circulating pipeline, 15℃ cold water through the third circulating pipeline into the photovoltaic heat collector heat absorption, and the photovoltaic heat collector complete heat exchange after temperature rise to about 45℃, under the action of the fourth three-way valve through the second branch pipe to the geothermal coil heat exchanger for heat storage, complete heat storage after water temperature reduction, then by the first water pump guided through the first circulating pipeline and the first branch to return to the third circulating pipeline, the cooling water through the third circulating pipeline to absorb the heat of photovoltaic heat collector, water temperature rises to 45℃, then under the second water pump into the next cycle. At the same time start the first circulating pipeline, under the action of the first water pump, 30℃ hot water through the first circulating pipeline into the geothermal coil heat exchanger, and the earth soil complete heat exchange after temperature reduction to about 20℃, again through the first circulating pipeline into the first heat exchanger. At this time, the third circulating pipeline starts the refrigeration cycle mode, the controller controls the first reversing valve, the second reversing valve, the sixth three-way valve, the seventh three-way valve and the eighth three-way valve open, under the action of the first reversing valve and the second reversing valve, the working medium in the heat pump cycle flows reversely, so that the function of the evaporator in the first heat exchanger and the condenser in the third heat exchanger are exchanged, the low temperature liquid working medium in the evaporator of the third heat exchanger absorbs the heat of the water in the third heat exchanger to complete the evaporation process, the low pressure gas state working medium after evaporation heat absorption enters the compressor through the bypass pipe under the action of the first reversing valve and the second reversing valve, becomes high pressure gas state working medium after pressure rise in the compressor, enters the condenser in the first heat exchanger through the bypass pipe, the fifth circulating pipeline, the third branch pipe and the fourth branch pipe under the action of the first reversing valve, the second reversing valve, the sixth three-way valve, the seventh three-way valve and the eighth three-way valve, the high pressure gas state working medium releases heat in the condenser in the first heat exchanger to complete the condensation liquefaction of the water in the first heat exchanger, the high pressure liquid working medium after completing the condensation liquefaction enters the expansion throttle valve through the third circulating pipeline, becomes low pressure liquid working medium under the action of the expansion throttle valve and returns to the evaporator in the third heat exchanger to continue the evaporation heat absorption. In this case, the temperature of the working medium in the evaporator of the third heat exchanger is 5℃, the temperature of the working medium in the condenser of the first heat exchanger is 60℃, the temperature of the water in the third heat exchanger decreases from 20℃ to 7℃, and the temperature of the water in the first heat exchanger increases from 25℃ to 45℃. The cold water stored in the third heat exchanger under the action of the third water pump through the fourth circulating pipeline to the fourth heat exchanger for cold storage, when there is a cold demand, the third temperature sensor detects that the water temperature in the fourth heat exchanger reaches about 7℃, under the action of the fourth water pump through the fifth circulating pipeline into the fan coil for indoor cooling.After the cooling is completed, the water temperature rises to about 20℃, and then the water is guided back to the fourth heat exchanger by the fifth water pump to enter the next cycle. At the same time, the third temperature sensor detects that the water temperature in the first heat exchanger rises to about 45℃. The heated water in the first heat exchanger exchanges heat with the geothermal coil heat exchanger through the first circulating pipeline, and the water temperature decreases. Then, under the action of the first water pump, the water enters the next cycle. When the room does not need cooling, the 7℃ cold water generated by the third heat exchanger is guided to the fourth heat exchanger through the fourth circulating pipeline by the third water pump for cold storage, ready for use by the user. When the first heat exchanger is short of water, the first pressure sensor detects that the pressure is lower than the set value, and the controller starts the first water supplement pump to pump water from the first water supplement tank for water supplement; when the system is short of water, the second pressure sensor detects that the pressure is lower than the set value, and the controller starts the second water supplement pump to pump water from the second water supplement tank for water supplement.

[0022] The electricity storage and power supply unit is connected to the power line network, and the electric energy generated by the photovoltaic heat collector is fully utilized and mobilized. When the geothermal and solar energy supply is sufficient to meet the indoor heating demand, the electric energy generated by the photovoltaic heat collector is stored in the storage battery through the MPPT controller. When the water temperature in the fourth heat exchanger in the system cannot reach the preset temperature of 45℃, the storage battery directly supplies power to the heater in the fourth heat exchanger to supplement heat to meet the system requirements; or the electric energy can be converted into 220V alternating current through the AC / DC bidirectional inverter and connected to the system to supply power to the electrical equipment in the system. The excess electric energy can be used as indoor electrical load, or connected to the power line network through the bidirectional electric meter. When the system is short of electricity, the electric energy in the power line network can also be called through the bidirectional electric meter.

[0023] The beneficial effects of the present application are as follows:

[0024] The photovoltaic heat and geothermal heat pump combined energy supply system provided by the present application utilizes the photovoltaic heat collector to realize heating and electricity generation at the same time, and can collect excess heat for heating and improve the geothermal temperature. Through effective control strategy and reasonable regulation of the operation mode of the system, the system can maintain efficient utilization of solar energy and geothermal energy, and reduce energy consumption. The temperature of the photovoltaic cell is always maintained within the optimal working range, the excess electric energy is stored in the storage battery, and the AC / DC bidirectional inverter is connected to the power line. When the system is short of heat, auxiliary heating is performed, and the power supply can be called when necessary to supplement the heat of the system. The heat and electricity generated by solar energy can be used for heating to the greatest extent. The geothermal energy is used as a heat storage and heat exchange device, which can assist in heating when the system is short of heat, store excess heat when the heat source of the system is sufficient, and also can fully exchange heat with the system when cooling is required in summer. The system fully utilizes geothermal energy and solar energy, two clean energy sources, can effectively solve the problem of soil thermal imbalance caused by long-term energy supply of single geothermal heat pump and low efficiency of traditional geothermal heat pump system, and has wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The whole structure schematic diagram of the photovoltaic and geothermal heat pump combined energy supply system.

[0026] Figure 2 The principle schematic diagram of the working condition one in the working principle of the energy supply system.

[0027] Figure 3 The principle schematic diagram of the working condition two in the working principle of the energy supply system.

[0028] Figure 4 The principle schematic diagram of the working condition three in the working principle of the energy supply system.

[0029] Figure 5 The principle schematic diagram of the working condition four in the working principle of the energy supply system.

[0030] The annotations in the above diagram are as follows:

[0031] 1, geothermal coil heat exchanger 2, photovoltaic heat collector 3, first heat exchanger 4, second heat exchanger

[0032] 5, third heat exchanger 6, fourth heat exchanger 7, first circulating pipeline 8, second circulating pipeline

[0033] 9, third circulating pipeline 10, fourth circulating pipeline 11, controller 12, first branch pipe

[0034] 13, second branch pipe 14, first three-way valve 15, second three-way valve 16, third three-way valve

[0035] 17, fourth three-way valve 18, first water pump 19, second water pump 20, first temperature sensor

[0036] 21, second temperature sensor 22, third branch pipe 23, fifth three-way valve 24, sixth three-way valve

[0037] 25, expansion throttle valve 26, first reversing valve 27, second reversing valve 28, compressor

[0038] 29, fourth branch pipe 30, seventh three-way valve 31, eighth three-way valve 32, first dryness detector

[0039] 33, second dryness detector 34, third water pump 35, first water supplement tank 36, first pressure sensor

[0040] 37, first water supplement pump 38, fifth circulating pipeline 39, fan coil 40, ninth three-way valve

[0041] 41, thirteenth three-way valve 42, fourth water pump 43, fifth water pump 44, second water supplement tank

[0042] 45, second pressure sensor 46, second water replenishment pump 47, fifth branch pipe 48, sixth branch pipe

[0043] 49, eleventh three-way valve 50, twelfth three-way valve 51, tenth three-way valve 52, fourteenth three-way valve

[0044] 53, seventh branch pipe 54, fifteenth three-way valve 55, eighth branch pipe 56, sixteenth three-way valve

[0045] 57, sixth water pump 58, third temperature sensor 59, heater 60, battery

[0046] 61, MPPT controller 62, AC / DC bidirectional inverter 63, bidirectional watt-hour meter. DETAILED DESCRIPTION

[0047] Please refer to Figures 1 to 5 as shown:

[0048] The photovoltaic and ground source heat pump combined energy supply system provided by the application comprises a ground heat coil heat exchanger 1, a photovoltaic collector 2, a first heat exchanger 3, a second heat exchanger 4, a third heat exchanger 5, a fourth heat exchanger 6, a first circulating pipeline 7, a second circulating pipeline 8, a third circulating pipeline 9, a fourth circulating pipeline 10 and a controller 11, wherein the first heat exchanger 3 is connected in communication with the ground heat coil heat exchanger 1 through the first circulating pipeline 7, the second heat exchanger 4 is connected in communication with the photovoltaic collector 2 through the second circulating pipeline 8, the first heat exchanger 3, the second heat exchanger 4 and the third heat exchanger 5 are connected in series through the third circulating pipeline 9, the third heat exchanger 8 and the fourth heat exchanger 6 are connected in communication through the fourth circulating pipeline 10, and the controller 11 is connected with and controls the working of the control valves and water pumps assembled on the first circulating pipeline 7, the second circulating pipeline 8, the third circulating pipeline 9 and the fourth circulating pipeline 10.

[0049] The first circulation pipeline 7 and the second circulation pipeline 8 are further connected with a first branch pipe 12 and a second branch pipe 13, the first branch pipe 12 is equipped with a first three-way valve 14 at the connection with the first circulation pipeline 7, the first branch pipe 12 is equipped with a second three-way valve 15 at the connection with the second circulation pipeline 8, the second branch pipe 13 is equipped with a third three-way valve 16 at the connection with the first circulation pipeline 7, the second branch pipe 13 is equipped with a fourth three-way valve 17 at the connection with the second circulation pipeline 8, the first circulation pipeline 7 between the first three-way valve 14 and the ground heat coil heat exchanger 1 is equipped with a first water pump 18, the second circulation pipeline 8 between the fourth three-way valve 17 and the photovoltaic heat collector 2 is equipped with a second water pump 19, the second circulation pipeline 8 at the rear of the fourth three-way valve 17 is equipped with a first temperature sensor 20, the photovoltaic heat collector 2 is equipped with a second temperature sensor 21, the first temperature sensor 20 and the second temperature sensor 21 are connected with the controller 11, the first temperature sensor 20 and the second temperature sensor 21 can transmit the collected data to the controller 11 in real time, the first three-way valve 14, the second three-way valve 15, the third three-way valve 16, the fourth three-way valve 17, the first water pump 18 and the second water pump 19 are connected with the controller 11 and are controlled to work by the controller 11.

[0050] The third circulating pipeline 9 is connected with a third branch pipe 22 at both ends of the first heat exchanger 3 and the second heat exchanger 4 connected in series, fifth and sixth three-way valves 23 and 24 are respectively arranged at the upper and lower ends of the third branch pipe 22, an expansion throttling valve 25 is arranged on the third circulating pipeline 9 between the fifth three-way valve 23 and the third heat exchanger 5, two bypass pipes connected in parallel are connected to the third circulating pipeline 9 between the sixth three-way valve 24 and the third heat exchanger 5, first and second reversing valves 26 and 27 are respectively arranged at the two ends of the two bypass pipes, a compressor 28 is arranged on the third circulating pipeline 9 between the first and second reversing valves 26 and 27, a fourth branch pipe 29 is arranged between the third circulating pipeline 9 and the third branch pipe 22 between the first heat exchanger 3 and the second heat exchanger 4, seventh and eighth three-way valves 30 and 31 are respectively arranged at the two ends of the fourth branch pipe 29, a first dryness detector 32 is arranged on the third circulating pipeline 9 between the first heat exchanger 3 and the seventh three-way valve 30, a second dryness detector 33 is arranged on the third circulating pipeline 9 between the second heat exchanger 4 and the sixth three-way valve 24, the first and second dryness detectors 32 and 33 are connected with the controller 11, the first and second dryness detectors 32 and 33 can transmit the collected data to the controller 11 in real time, and the controller 11 is connected with the fifth, sixth, seventh and eighth three-way valves 23, 24, 30 and 31, the expansion throttling valve 25, the first and second reversing valves 26 and 27, the compressor 28, and controls the working of the fifth, sixth, seventh and eighth three-way valves 23, 24, 30 and 31, the expansion throttling valve 25, the first and second reversing valves 26 and 27, and the compressor 28.

[0051] The fourth circulating pipeline 10 is arranged with a third water pump 34, and the fourth circulating pipeline 10 is connected with a first water supplement tank 35 through a transmission pipe, the transmission pipe between the first water supplement tank 35 and the fourth circulating pipeline 10 is arranged with a first pressure sensor 36 and a first water supplement pump 37, the first pressure sensor 36 is connected with the controller 11 and can transmit the collected data to the controller 11 in real time, and the controller 11 is connected with the third water pump 34 and the first water supplement pump 37 and controls the working of the third water pump 34 and the first water supplement pump 37.

[0052] The fourth heat exchanger 6 is also connected with a fifth circulating pipeline 38, two parallel fan-coil units 39 are assembled on the fifth circulating pipeline 38 through bypass pipes, the fifth circulating pipeline 38 is respectively connected with a ninth three-way valve 40 and a thirteenth three-way valve 41 at two ends of the bypass pipes, a fourth water pump 42 is assembled on the fifth circulating pipeline 38 between the ninth three-way valve 40 and the fourth heat exchanger 6, a fifth water pump 43 is assembled on the fifth circulating pipeline 38 between the thirteenth three-way valve 41 and the fourth heat exchanger 6, the fifth circulating pipeline 38 is connected with a second water supplement tank 44 through a transmission pipe, a second pressure sensor 45 and a second water supplement pump 46 are assembled on the transmission pipe between the second water supplement tank 44 and the fifth circulating pipeline 38, the second pressure sensor 45 is connected with the controller 11, the second pressure sensor 45 can transmit the collected data to the controller 11 in real time, and the controller 11 is connected with and controls the working of the ninth three-way valve 40, the thirteenth three-way valve 41, the fourth water pump 42, the fifth water pump 43 and the second water supplement pump 46.

[0053] The second circulating pipeline 8 is connected with the fifth circulating pipeline 38 through a fifth branch pipe 47 and a sixth branch pipe 48, the fifth branch pipe 47 is connected with the second circulating pipeline 8 and is provided with an eleventh three-way valve 49, the fifth branch pipe 47 is connected with the fifth circulating pipeline 38 and is provided with a twelfth three-way valve 50, the sixth branch pipe 48 is connected with the second circulating pipeline 8 and is provided with a thirteenth three-way valve 51, the sixth branch pipe 48 is connected with the fifth circulating pipeline 38 and is provided with a fourteenth three-way valve 52, the fourth heat exchanger 6 is connected with the fifth branch pipe 47 through a seventh branch pipe 53, the seventh branch pipe 53 is connected with the fifth branch pipe 47 and is provided with a fifteenth three-way valve 54, the fourth heat exchanger 6 is connected with the sixth branch pipe 48 through an eighth branch pipe 55, the eighth branch pipe 55 is connected with the sixth branch pipe 48 and is provided with a sixteenth three-way valve 56, and the eighth branch pipe 55 is also provided with a sixth water pump 57, the eleventh three-way valve 49, the twelfth three-way valve 50, the thirteenth three-way valve 51, the fourteenth three-way valve 52, the fifteenth three-way valve 54, the sixteenth three-way valve 56 and the sixth water pump 57 are connected with and controlled by the controller 11.

[0054] The first heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5, and the fourth heat exchanger 6 are water tank type heat exchangers, and the flowing medium inside the water tank type heat exchangers is water. Each of the first heat exchanger 3, the second heat exchanger 4, and the third heat exchanger 5 is equipped with an evaporator or a condenser, and the fourth heat exchanger 6 is equipped with a heat exchange coil. Each of the first heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5, and the fourth heat exchanger 6 is equipped with a third temperature sensor 58. The third temperature sensor 58 is connected to the controller 11 and can transmit the collected data to the controller 11 in real time.

[0055] The fourth heat exchanger 6 is also equipped with a heater 59, which is connected to a battery 60. The battery 60 provides power to the heater 59. The heater 59 is connected to a controller 11 and is controlled by the controller 11. The battery 60 is connected to the controller 11 and provides power to the controller 11.

[0056] The battery 60 is connected to the photovoltaic collector 2. An MPPT controller 61 is installed on the connection line between the photovoltaic collector 2 and the battery 60. The MPPT controller 61 is a maximum power point tracking solar controller. The MPPT controller 61 can detect the power generation voltage of the photovoltaic panel in the photovoltaic collector 2 in real time and track the highest voltage and current value, so that the photovoltaic panel charges the battery 60 with maximum power output. The battery 60 is also connected to a power supply line. The battery 60 is connected to the electrical devices in the system through the power supply line. The battery 60 is also connected to the mains power line through a line. An AC / DC bidirectional inverter 62 and a bidirectional electricity meter 63 are installed in sequence on the line connecting the battery 60 and the mains power line. Excess electrical energy in the battery 60 can be sent to the mains power line. When the electrical energy in the battery 60 is insufficient to supply power to the electrical devices in the system, the insufficient electrical energy is provided by the mains power line.

[0057] The geothermal coil heat exchanger 1, the photovoltaic heat collector 2, the first heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5, the fourth heat exchanger 6, the first circulating pipeline 7, the second circulating pipeline 8, the third circulating pipeline 9, the fourth circulating pipeline 10, the controller 11, the first three-way valve 14, the second three-way valve 15, the third three-way valve 16, the fourth three-way valve 17, the first water pump 18, the second water pump 19, the first temperature sensor 20, the second temperature sensor 21, the fifth three-way valve 23, the sixth three-way valve 24, the expansion throttle valve 25, the first reversing valve 26, the second reversing valve 27, the compressor 28, the seventh three-way valve 30, the eighth three-way valve 31, the first dryness detector 32, the second dryness detector 33, the third water pump 34, the first pressure sensor 36, the first water supplement pump 37, the fifth circulating pipeline 38, the fan coil 39, the ninth three-way valve 40, the thirteenth three-way valve 41, the fourth water pump 42, the fifth water pump 43, the second pressure sensor 45, the second water supplement pump 46, the eleventh three-way valve 49, the twelfth three-way valve 50, the tenth three-way valve 51, the fourteenth three-way valve 52, the fifteenth three-way valve 54, the sixteenth three-way valve 56, the sixth water pump 57, the third temperature sensor 58, the heater 59, the battery 60, the MPPT controller 61, the AC / DC bidirectional inverter 62 and the bidirectional watt-hour meter 63 are all assembled from existing devices, therefore, the specific model and specifications are not described in detail.

[0058] Working principle of the present application:

[0059] The photovoltaic light heat and ground source heat pump combined energy supply system provided by the present application utilizes the working principle of the photovoltaic heat collector as follows:

[0060] Working condition one: as shown in Figure 2 Figure 2 ​The arrow direction in the figure represents the circulating direction of the medium in this working condition. In winter, the photovoltaic heat is enough to meet the heating demand. The second temperature sensor 21 detects the temperature rise of the photovoltaic collector 2, and the controller 11 starts the second water pump 19. Under the action of the second water pump 19, 7℃ low-temperature water enters the second circulating pipeline 8 from the sixth branch pipe 48. The 7℃ low-temperature water passing through the second circulating pipeline 8 takes away the heat generated by the photovoltaic collector 2. The second temperature sensor 21 detects that the water temperature rises to 45℃ and opens the eleventh three-way valve 49 through the action of the controller 11. The 45℃ hot water enters the fifth branch pipe 47 under the action of the eleventh three-way valve 49. When the heating demand is required, the first temperature sensor 20 detects that the water temperature reaches 45℃, and the 45℃ hot water enters the fifth circulating pipeline 38 through the fifth branch pipe 47 under the action of the eleventh three-way valve 49 and the twelfth three-way valve 50 to directly heat the fan coil 39. After the heating is completed, the water temperature decreases to about 35℃, and then is guided back to the second circulating pipeline 8 through the sixth branch pipe 48 under the action of the fifth water pump 43 and the fourteenth three-way valve 52. The cooled water exchanges heat with the photovoltaic collector 2 through the second circulating pipeline 8, and the water temperature rises to 45℃, and then enters the next cycle under the action of the second water pump 19. When the room does not need heating, the 45℃ hot water generated by the photovoltaic collector 2 can be guided to the fourth heat exchanger 6 for heat storage under the action of the fifteenth three-way valve 54 through the seventh branch pipe 53, so as to be used by the user. After the heat storage is completed, the cooled water is guided back to the second circulating pipeline 8 through the eighth branch pipe 55 and the sixth branch pipe 48 under the action of the sixth water pump 57 and the sixteenth three-way valve 56. The cooled water absorbs the heat of the photovoltaic collector 2 through the second circulating pipeline 8, and the water temperature rises to 45℃, and then enters the next cycle under the action of the second water pump 19. When the room does not need heating and the heat in the fourth heat exchanger 6 is full, the controller 11 controls the first three-way valve 14, the second three-way valve 15, the third three-way valve 16 and the fourth three-way valve 17 to open. The 45℃ hot water generated by the photovoltaic collector 2 can be guided to the geothermal coil heat exchanger 1 for heat storage under the action of the fourth three-way valve 17 through the second branch pipe 13. The water after the heat storage is completed enters the second circulating pipeline 8 through the first branch pipe 12 under the action of the first water pump 18, the first three-way valve 14 and the second three-way valve 15. The cooled water absorbs the heat of the photovoltaic collector 2 through the second circulating pipeline 8, and the water temperature rises to 45℃, and then enters the next cycle under the action of the second water pump 19. When the system is short of water, the second pressure sensor 45 detects that the pressure is lower than the set value, and the controller 11 starts the second water supplement pump 46 to pump the water in the second water supplement tank 44 for water supplement;

[0061] Working condition two: as shown in Figure 3 Figure 3 ​The arrow direction in the figure represents the circulating direction of the medium in this working condition. In winter, there is light, and the photovoltaic heat is not enough to meet the heating demand. The second temperature sensor 21 detects that the photovoltaic collector 2 is warming up, and the controller 11 controls the second water pump 19 to start. Under the action of the second water pump 19, the low-temperature water at 7°C carries away the heat generated by the photovoltaic light-heat collector 2 through the second circulating pipeline 8, and the water temperature rises. Under the action of the eleventh three-way valve 49, it enters the second heat exchanger 4 through the second circulating pipeline 8. At this time, the third circulating pipeline 9 starts the heat pump circulation mode, and the low-temperature liquid working medium in the evaporator in the second heat exchanger 4 absorbs the heat of the water body in the second heat exchanger 4 to evaporate. The low-pressure gaseous working medium after evaporation and heat absorption enters the compressor 28 through the third circulating pipeline 9, and becomes high-pressure gaseous working medium after being pressurized by the compressor 28, and enters the condenser in the third heat exchanger 5. The high-pressure gaseous working medium releases heat in the condenser of the third heat exchanger 5 to the water body in the third heat exchanger 5 to complete condensation and liquefaction. The high-pressure liquid working medium after completing condensation and liquefaction becomes low-pressure liquid working medium after passing through the expansion throttle valve 25. The controller 11 controls the fifth three-way valve 23, the eighth three-way valve 31 and the seventh three-way valve 30 to open. The low-pressure liquid working medium enters the third circulating pipeline 9 through the third branch pipe 22 and the fourth branch pipe 29 under the action of the fifth three-way valve 23, the eighth three-way valve 31 and the seventh three-way valve 30, and then returns to the evaporator in the second heat exchanger 4 through the third circulating pipeline 9 to continue evaporation and heat absorption. In this working condition, the temperature of the working medium in the evaporator in the second heat exchanger 4 is 5°C, the temperature of the working medium in the condenser in the third heat exchanger 5 is 60°C, the temperature of the water body in the second heat exchanger 4 decreases to 7°C after heat absorption, and the temperature of the water body in the third heat exchanger 5 rises from 20°C to 50°C. When the second dryness detector 33 detects that the working medium in the evaporator in the second heat exchanger 4 is not completely evaporated, the first circulating pipeline 7 is started to heat the system synchronously. The controller 11 controls the first water pump 18 to flow at low speed in the first circulating pipeline 7 in a low-power mode. Under the action of the first water pump 18, the low-temperature water at 7°C enters the geothermal coil heat exchanger 1 through the first circulating pipeline 7, and completes heat exchange with the earth soil to rise the temperature to about 15°C, and then enters the first heat exchanger 3 through the first circulating pipeline 7.At this time, the controller 11 controls the eighth three-way valve 31 to close, and the low-temperature liquid working medium in the evaporator of the first heat exchanger 3 absorbs the heat of the water body of the first heat exchanger 3 to evaporate, and the first dryness detector 32 detects that the working medium in the evaporator of the first heat exchanger 3 has not completely evaporated. The liquid working medium that has not completely evaporated enters the evaporator in the second heat exchanger 4 through the third circulating pipeline 9 to continue to absorb heat. At this time, the second dryness detector 33 detects that the working medium in the second heat exchanger 4 has completely evaporated. If the working medium in the second heat exchanger 4 has not completely evaporated, the power of the first water pump 18 is increased to accelerate the flow of water in the first circulating pipeline 7. The low-pressure gaseous working medium after completing the evaporation and heat absorption enters the compressor 28 through the third circulating pipeline 9, and becomes high-pressure gaseous working medium after being pressurized by the compressor 28, and enters the condenser in the third heat exchanger 5. The high-pressure gaseous working medium releases heat in the condenser of the third heat exchanger 5 to complete condensation and liquefaction. The high-pressure liquid working medium after completing condensation and liquefaction becomes low-pressure liquid working medium after passing through the expansion throttle valve 25, and returns to the evaporator in the first heat exchanger 3 through the third circulating pipeline 9 to continue evaporation and heat absorption. In this working condition, the temperature of the working medium in the evaporator of the first heat exchanger 3 is 5°C, the temperature of the working medium in the evaporator of the second heat exchanger 4 is 10°C, the temperature of the working medium in the condenser of the third heat exchanger 5 is 60°C, and the temperature of the water body in the first heat exchanger 3 and the second heat exchanger 4 decreases to 7°C after heat absorption. The temperature of the water body in the third heat exchanger 5 increases from 20°C to 50°C. The heat stored in the third heat exchanger 5 is stored in the fourth heat exchanger 6 through the fourth circulating pipeline 10 under the action of the third water pump 34. When the useful heat is required, the water temperature in the fourth heat exchanger 6 reaches about 45°C, and the water enters the fan coil 39 through the fifth circulating pipeline 38 under the action of the fourth water pump 42 to supply heat to the room. After completing the heating, the water temperature decreases to about 35°C, and then returns to the fourth heat exchanger 6 by the fifth water pump 43 to enter the next cycle. At the same time, the third temperature sensor 58 detects that the water temperature in the first heat exchanger 3 and the second heat exchanger 4 decreases to about 7°C. The water in the first heat exchanger 3 is heated by the geothermal heat exchanger 1 through the first circulating pipeline 7, and then enters the next cycle under the action of the first water pump 18. The water in the second heat exchanger 4 is heated by the photovoltaic heat collector 2 through the second circulating pipeline 8, and then enters the next cycle under the action of the second water pump 19. When the room does not require heating, the 50°C hot water produced by the third heat exchanger 5 is stored in the fourth heat exchanger 6 through the fourth circulating pipeline 10 under the action of the third water pump 34 for user use.When the room does not need heating and the heat in the fourth heat exchanger 6 has been accumulated, the controller 11 controls the first three-way valve 14, the second three-way valve 15, the third three-way valve 16 and the fourth three-way valve 17 to be opened, the hot water generated by the photovoltaic collector 2 can be stored in the geothermal coil heat exchanger 1 through the second branch pipe 13 under the action of the fourth three-way valve 17, after the heat storage is completed, the water enters the second circulating pipeline 8 through the first branch pipe 12 under the action of the first water pump 18, the first three-way valve 14 and the second three-way valve 15, the cooled water is heat exchanged with the photovoltaic collector 2 through the second circulating pipeline 8, the water temperature rises, and then enters the next cycle under the second water pump 19. When the third temperature sensor 58 detects that the water temperature in the fourth heat exchanger 6 does not reach the preset value of 45℃, the controller 11 instructs the storage battery 60 to supply power to the heater 59 to heat the fourth heat exchanger 6, if the heating requirement is still not met, the city power supply line is introduced to provide power to the heater 59 through the bidirectional watt-hour meter 63 and the AC / DC bidirectional inverter 62 for heating, so that the water temperature in the fourth heat exchanger 6 reaches the preset value of 45℃. When the first pressure sensor 36 detects that the pressure is lower than the set value when the third heat exchanger 5 is short of water, the controller 11 starts the first water supplement pump 37 to suck the water in the first water supplement tank 35 for water supplement; when the second pressure sensor 45 detects that the pressure is lower than the set value when the system is short of water, the controller 11 starts the second water supplement pump 46 to suck the water in the second water supplement tank 44 for water supplement.

[0062] Case three: as shown in Figure 4 Figure 4 ​The arrows indicate the circulation direction of the flowing medium under this operating condition, in winter when there is no sunlight. The second temperature sensor 21 does not detect a temperature rise in the photovoltaic collector 2, and the second circulation pipeline 8 stops operating. Under the action of the first water pump 18, 7°C low-temperature water enters the geothermal coil heat exchanger 1 through the first circulation pipeline 7. After exchanging heat with the soil, the temperature rises to about 15°C, and then enters the first heat exchanger 3 through the first circulation pipeline 7. At this time, the heat pump circulation mode is activated on the third circulation pipeline 9. The controller 11 controls the opening of the sixth three-way valve 24, the seventh three-way valve 30, and the eighth three-way valve 31. The low-temperature liquid working fluid in the evaporator of the first heat exchanger 3 absorbs heat from the water in the first heat exchanger 3 to complete the evaporation process. At this time, the first dryness detector 32 detects that the working fluid in the evaporator of the first heat exchanger 3 has completely evaporated. If the working fluid in the evaporator of the first heat exchanger 3 has not completely evaporated, the power of the first water pump 18 is increased to accelerate the flow of water in the first circulation pipeline 7, evaporating the low-pressure gaseous working fluid after heat absorption. Under the action of the sixth three-way valve 24, the seventh three-way valve 30, and the eighth three-way valve 31, the fluid enters the compressor 28 through the fourth branch pipe 29, the third branch pipe 22, and the third circulation pipe 9. After being pressurized by the compressor 28, it becomes a high-pressure gaseous working fluid and enters the condenser in the third heat exchanger 5. The high-pressure gaseous working fluid releases heat to the water in the third heat exchanger 5 in the condenser, completing condensation and liquefaction. After condensation and liquefaction, the high-pressure liquid working fluid becomes a low-pressure liquid working fluid after passing through the expansion throttle valve 25 and returns to the evaporator in the first heat exchanger 3 through the third circulation pipe 9 to continue evaporation and heat absorption. Under this condition, the temperature of the working fluid in the evaporator in the first heat exchanger 3 is 5℃, the temperature of the working fluid in the condenser in the third heat exchanger 5 is 60℃, the water temperature in the first heat exchanger 3 drops from 15℃ to 7℃, and the water temperature in the third heat exchanger 5 rises from 20℃ to 50℃. The heat stored in the third heat exchanger 5 is transferred to the fourth heat exchanger 6 via the fourth circulation pipe 10 by the third water pump 34. When heating is required, the third temperature sensor 58 detects that the water temperature in the fourth heat exchanger 6 has reached approximately 45°C. Then, under the action of the fourth water pump 42, the water enters the fan coil unit 39 via the fifth circulation pipe 38 to provide indoor heating. After heating is completed, the water temperature drops to approximately 35°C and is then guided back to the fourth heat exchanger 6 by the fifth water pump 43 to enter the next cycle. Simultaneously, the third temperature sensor 58 detects that the water temperature in the first heat exchanger 3 has dropped to approximately 7°C. The cooled water in the first heat exchanger 3 exchanges heat with the geothermal coil heat exchanger 1 via the first circulation pipe 7, causing the water temperature to rise. Then, under the action of the first water pump 18, it enters the next cycle. When heating is not required in the room, the 50°C hot water generated by the third heat exchanger 5 is transferred to the fourth heat exchanger 6 via the fourth circulation pipe 10 by the third water pump 34 for heat storage, ready for user use.When the third temperature sensor 58 detects that the water temperature in the fourth heat exchanger 6 does not reach the preset value of 45℃, the controller 11 instructs the battery 60 to supply power to the heater 59 to heat the fourth heat exchanger 6. If the heating requirement is still not met, the AC power supply line is introduced to provide power to the heater 59 through the bidirectional electric meter 63 and the AC / DC bidirectional inverter 62 for heating, so that the water temperature in the fourth heat exchanger 6 reaches the preset value of 45℃. When the third heat exchanger 5 is water-deficient, the first pressure sensor 36 detects that the pressure is lower than the set value, and the controller 11 starts the first water supplement pump 37 to suck the water in the first water supplement tank 35 for water supplement. When the system is water-deficient, the second pressure sensor 45 detects that the pressure is lower than the set value, and the controller 11 starts the second water supplement pump 46 to suck the water in the second water supplement tank 44 for water supplement.

[0063] Working condition four: as shown in Figure 5 Figure 5 ​The arrow direction in the figure represents the circulating direction of the medium in this working condition. In summer, the second temperature sensor 21 does not detect the temperature rise of the photovoltaic collector 2, and the second circulating pipeline 8 stops running. When the second temperature sensor 21 detects the temperature rise of the photovoltaic collector 2, the controller 11 controls the first water pump 18, the second water pump 19, the first three-way valve 14, the second three-way valve 15, the third three-way valve 16 and the fourth three-way valve 17 to open. Under the action of the first water pump 18, the second water pump 19, the first three-way valve 14 and the second three-way valve 15, 15℃ cold water in the geothermal coil heat exchanger 1 enters the third circulating pipeline 9 through the first circulating pipeline 7 and the first branch pipe 12, and then enters the photovoltaic collector 2 to absorb heat, and the temperature rises to about 45℃ after heat exchange with the photovoltaic collector 2. Under the action of the fourth three-way valve 17, the water is stored in the geothermal coil heat exchanger 1 through the second branch pipe 13, and then the temperature of the water decreases after heat storage, and then the water is guided by the first water pump 18 to return to the third circulating pipeline 9 through the first circulating pipeline 7 and the first branch pipe 12. The cooled water absorbs the heat of the photovoltaic collector 2 through the third circulating pipeline 9, and the temperature of the water rises to 45℃, and then the water enters the next cycle under the action of the second water pump 19. At the same time, the first circulating pipeline 7 is started, and the hot water with a temperature of 30℃ enters the geothermal coil heat exchanger 1 through the first circulating pipeline 7 under the action of the first water pump 18, and then the temperature of the water decreases to about 20℃ after heat exchange with the earth soil, and then the water enters the first heat exchanger 3 through the first circulating pipeline 7. At this time, the third circulating pipeline 9 starts the refrigeration cycle mode, and the controller 11 controls the first reversing valve 26, the second reversing valve 27, the sixth three-way valve 24, the seventh three-way valve 30 and the eighth three-way valve 31 to open. Under the action of the first reversing valve 26 and the second reversing valve 27, the working medium in the heat pump cycle flows reversely, so that the functions of the evaporator in the first heat exchanger 3 and the condenser in the third heat exchanger 5 are exchanged. The low-temperature liquid working medium in the evaporator of the third heat exchanger 5 absorbs the heat of the water in the third heat exchanger 5 to complete the evaporation process. The low-pressure gaseous working medium after evaporation absorbs heat enters the compressor 28 through the bypass pipe under the action of the first reversing valve 26 and the second reversing valve 27, and then becomes high-pressure gaseous working medium after pressure rising in the compressor 28. The high-pressure gaseous working medium enters the condenser in the first heat exchanger 3 through the bypass pipe, the fifth circulating pipeline 38, the third branch pipe 22 and the fourth branch pipe 29 under the action of the first reversing valve 26, the second reversing valve 27, the sixth three-way valve 24, the seventh three-way valve 30 and the eighth three-way valve 31, and then releases heat to the water in the first heat exchanger 3 to complete the condensation and liquefaction. The high-pressure liquid working medium after condensation and liquefaction enters the expansion throttle valve 25 through the third circulating pipeline 9, and then becomes low-pressure liquid working medium under the action of the expansion throttle valve 25 and returns to the evaporator in the third heat exchanger 5 to continue the evaporation and heat absorption. In this working condition, the temperature of the working medium in the evaporator of the third heat exchanger 5 is 5℃, the temperature of the working medium in the condenser of the first heat exchanger 3 is 60℃, the temperature of the water in the third heat exchanger 5 decreases from 20℃ to 7℃, and the temperature of the water in the first heat exchanger 3 increases from 25℃ to 45℃.The cold water stored in the third heat exchanger 5 is guided to the fourth heat exchanger 6 by the fourth circulating pipeline 10 under the action of the third water pump 34 for cold storage. When the cold demand is needed, the third temperature sensor 38 detects that the water temperature in the fourth heat exchanger 6 reaches about 7℃, and then the water is guided into the fan coil 39 by the fourth water pump 42 through the fifth circulating pipeline 38 to supply cold to the indoor. After the cold supply is completed, the water temperature rises to about 20℃, and then the water is guided back to the fourth heat exchanger 6 by the fifth water pump 43 for the next cycle. At the same time, the third temperature sensor 38 detects that the water temperature in the first heat exchanger 3 rises to about 45℃. The heated water in the first heat exchanger 3 is exchanged with the geothermal coil heat exchanger 1 through the first circulating pipeline 7, and the water temperature is lowered. Then the water is guided into the next cycle by the first water pump 18. When the room does not need to be cooled, the 7℃ cold water generated by the third heat exchanger 5 is guided to the fourth heat exchanger 6 by the fourth circulating pipeline 10 under the action of the third water pump 34 for cold storage, ready for use by the user. When the water in the third heat exchanger 5 is insufficient, the first pressure sensor 36 detects that the pressure is lower than the set value, and the controller 11 starts the first water supplement pump 37 to pump the water in the first water supplement tank 35 for water supplement; when the water in the system is insufficient, the second pressure sensor 45 detects that the pressure is lower than the set value, and the controller 11 starts the second water supplement pump 46 to pump the water in the second water supplement tank 44 for water supplement.

[0064] The power storage and supply unit is connected to the power line network to fully utilize and mobilize the electric energy generated by the photovoltaic collector 2. When the geothermal and solar energy supply is sufficient to meet the indoor heating demand, the electric energy generated by the photovoltaic collector 2 is stored in the storage battery 60 through the MPPT controller 61. When the water temperature in the fourth heat exchanger 6 does not reach the preset temperature of 45℃, the storage battery 60 directly supplies power to the heater 59 in the fourth heat exchanger 6 to supplement heat to meet the system requirements; or the AC / DC bidirectional inverter 62 is converted into 220V alternating current to be connected to the system to supply power to the electrical equipment in the system. The excess power can be used as indoor electrical load, or the electric energy in the power line network can be called through the bidirectional electric meter 63.

[0065] The photovoltaic and ground source heat pump combined energy supply system provided by the application can realize heating and power generation by using a photovoltaic collector, and can collect excess heat for heating and improving the ground heat temperature. Through effective control strategies and reasonable regulation of the operation mode of the system, the system can maintain efficient use of solar energy and ground heat energy, and reduce energy consumption. The temperature of the photovoltaic cell is always maintained within the optimal working range, the excess power is stored in the storage battery 60, and is connected to the power line through the AC / DC bidirectional inverter 62, and auxiliary heating is performed when the system heating is insufficient, and the power supply can be called to supplement the heat of the system when necessary, so that the heat and electricity generated by solar energy can be used for heating to the maximum extent. The ground heat energy is used as an energy storage and heat exchange device, which can assist in heating when the system heating is insufficient, store excess heat when the heat source of the system is sufficient, and fully exchange heat with the system when cooling is required in summer. The system fully utilizes the two clean energy sources of ground heat energy and solar energy, can effectively solve the problems of soil heat imbalance caused by long-term energy supply of single ground source heat pump and low efficiency of traditional ground source heat pump system, and has wide application prospect.

Claims

1. A photovoltaic thermal and ground source heat pump combined energy supply system, comprising a geothermal coil heat exchanger, a photovoltaic collector, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a first circulation pipeline, a second circulation pipeline, a third circulation pipeline, a fourth circulation pipeline, and a controller, wherein the first heat exchanger is connected to the geothermal coil heat exchanger via the first circulation pipeline, the second heat exchanger is connected to the photovoltaic collector via the second circulation pipeline, the first, second, and third heat exchangers are connected in series via the third circulation pipeline, the third and fourth heat exchangers are connected via the fourth circulation pipeline, and the controller is connected to control valves mounted on the first, second, third, and fourth circulation pipelines and water pumps respectively, and controls the operation of the control valves and water pumps, characterized in that: A third branch pipe is connected to both ends of the third circulation pipeline of the first and second heat exchangers connected in series on the third circulation pipeline. A fifth three-way valve and a sixth three-way valve are respectively installed at the connection points of the upper and lower ends of the third branch pipe to the third circulation pipeline. An expansion throttle valve is installed on the third circulation pipeline between the fifth three-way valve and the third heat exchanger. Two parallel bypass pipes are connected to the third circulation pipeline between the sixth three-way valve and the third heat exchanger. A first reversing valve and a second reversing valve are respectively installed at the connection points of the two bypass pipes to the third circulation pipeline. A compressor is installed on the third circulation pipeline between the first and second reversing valves. A fourth branch pipe is installed between the third branch pipe and the third circulation pipeline between the first and second heat exchangers. Both ends of the fourth branch pipe are connected to the third circulation pipeline. A seventh three-way valve and an eighth three-way valve are respectively installed at the connection between the first heat exchanger and the third branch pipe. A first dryness detector is installed on the third circulation pipe between the first heat exchanger and the seventh three-way valve. A second dryness detector is installed on the third circulation pipe between the second heat exchanger and the sixth three-way valve. Both the first and second dryness detectors are connected to the controller. The first and second dryness detectors can transmit the collected data to the controller in real time. The controller is connected to the fifth three-way valve, the sixth three-way valve, the expansion throttle valve, the first reversing valve, the second reversing valve, the compressor, the seventh three-way valve, and the eighth three-way valve. The controller controls the operation of the fifth three-way valve, the sixth three-way valve, the expansion throttle valve, the first reversing valve, the second reversing valve, the compressor, the seventh three-way valve, and the eighth three-way valve.

2. The photovoltaic thermal and ground source heat pump combined energy supply system according to claim 1, characterized in that: The first and second circulation pipelines are connected by a first branch pipe and a second branch pipe. A first three-way valve is installed at the connection between the first branch pipe and the first circulation pipeline. A second three-way valve is installed at the connection between the first branch pipe and the second circulation pipeline. A third three-way valve is installed at the connection between the second branch pipe and the first circulation pipeline. A fourth three-way valve is installed at the connection between the second branch pipe and the second circulation pipeline. A first water pump is installed on the first circulation pipeline between the first three-way valve and the geothermal coil heat exchanger. A second water pump is installed on the second circulation pipeline between the fourth three-way valve and the photovoltaic collector. A first temperature sensor is installed on the second circulation pipeline downstream of the fourth three-way valve. A second temperature sensor is installed on the photovoltaic collector. The first and second temperature sensors are connected to the controller and can transmit the collected data to the controller in real time. The first three-way valve, the second three-way valve, the third three-way valve, the fourth three-way valve, the first water pump, and the second water pump are all connected to the controller and controlled by the controller.

3. The photovoltaic thermal and ground source heat pump combined energy supply system according to claim 1, characterized in that: The fourth circulation pipeline is equipped with a third water pump. The fourth circulation pipeline is connected to a first water supply tank through a transmission pipe. A first pressure sensor and a first water supply pump are installed on the transmission pipe between the first water supply tank and the fourth circulation pipeline. The first pressure sensor is connected to a controller and can transmit the collected data to the controller in real time. The controller is connected to the third water pump and the first water supply pump respectively and controls the operation of the third water pump and the first water supply pump.

4. The photovoltaic thermal and ground source heat pump combined energy supply system according to claim 1, characterized in that: The fourth heat exchanger is also connected to a fifth circulation pipeline. Two fan coil units are installed in parallel on the fifth circulation pipeline via bypass pipes. A ninth three-way valve and a thirteenth-way valve are respectively installed at the connection points between the fifth circulation pipeline and the two bypass pipes. A fourth water pump is installed on the fifth circulation pipeline between the ninth three-way valve and the fourth heat exchanger. A fifth water pump is installed on the fifth circulation pipeline between the thirteenth-way valve and the fourth heat exchanger. The fifth circulation pipeline is connected to a second makeup water tank via a transmission pipe. A second pressure sensor and a second makeup water pump are installed on the transmission pipe between the second makeup water tank and the fifth circulation pipeline. The second pressure sensor is connected to a controller and can transmit the collected data to the controller in real time. The controller is connected to and controls the operation of the ninth three-way valve, the thirteenth-way valve, the fourth water pump, the fifth water pump, and the second makeup water pump.

5. A photovoltaic thermal and ground source heat pump combined energy supply system according to claim 1 or 4, characterized in that: The second circulation pipeline is connected to the fifth circulation pipeline via the fifth and sixth branch pipes respectively. An eleventh three-way valve is installed at the connection between the fifth branch pipe and the second circulation pipeline, a twelfth three-way valve is installed at the connection between the fifth branch pipe and the fifth circulation pipeline, a thirteenth three-way valve is installed at the connection between the sixth branch pipe and the second circulation pipeline, and a fourteenth three-way valve is installed at the connection between the sixth branch pipe and the fifth circulation pipeline. The fourth heat exchanger is connected to the fifth branch pipe via the seventh branch pipe, and a fifteenth three-way valve is installed at the connection between the seventh branch pipe and the fifth branch pipe. The fourth heat exchanger is connected to the sixth branch pipe via the eighth branch pipe, and a sixteenth three-way valve is installed at the connection between the eighth branch pipe and the sixth branch pipe. A sixth water pump is also installed on the eighth branch pipe. The eleventh, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth three-way valves and the sixth water pump are all connected to the controller and controlled by the controller.

6. The photovoltaic thermal and ground source heat pump combined energy supply system according to claim 1, characterized in that: The first, second, third, and fourth heat exchangers are water tank type heat exchangers, with water as the flowing medium inside. Each of the first, second, and third heat exchangers is equipped with an evaporator or condenser, while the fourth heat exchanger is equipped with a heat exchange coil. Each of the first, second, third, and fourth heat exchangers is equipped with a third temperature sensor, which is connected to the controller and can transmit the collected data to the controller in real time.

7. A photovoltaic thermal and ground source heat pump combined energy supply system according to claim 1, characterized in that: The fourth heat exchanger is also equipped with a heater, which is connected to a battery that provides power to the heater. The heater is connected to a controller and is controlled by the controller. The battery is connected to the controller and provides power to the controller.

8. A photovoltaic thermal and ground source heat pump combined energy supply system according to claim 7, characterized in that: The battery is connected to the photovoltaic collector. An MPPT controller is installed on the connection line between the photovoltaic collector and the battery. The MPPT controller is a maximum power point tracking solar controller. The MPPT controller can detect the power generation voltage of the photovoltaic panels in the photovoltaic collector in real time and track the highest voltage and current value, so that the photovoltaic panels charge the battery with maximum power output. The battery is also connected to a power supply line, which connects the battery to the electrical devices in the system. The battery is also connected to the mains power line. An AC / DC bidirectional inverter and a bidirectional electricity meter are installed in sequence on the line connecting the battery and the mains power line. Excess electrical energy in the battery can be transmitted to the mains power line. When the electrical energy in the battery is insufficient to supply power to the electrical devices in the system, the insufficient electrical energy is provided by the mains power line.

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