Ground source heat pump coupling system based on photovoltaic light and heat
Technical Field
The invention belongs to the field of photovoltaic/thermal and heat pumps, and particularly relates to a ground source heat pump coupling system based on photovoltaic photo-thermal.
Background
With the continuous increase of population and economy, the demand of human beings on energy is larger and larger, so that the traditional energy is exhausted increasingly, the ecological environment is seriously damaged, and the exploration of new clean energy becomes a new trend of global energy development. The method improves the utilization efficiency of the existing energy and accelerates the development of new energy, and is a main way for solving two fundamental problems of energy and environment in the development process of human beings. Solar energy is widely concerned by people as one of the most abundant clean and renewable energy sources.
The utilization of solar energy is mainly divided into two aspects of photoelectric conversion and photothermal conversion. In the aspect of solar photovoltaic power generation application, the development of the photovoltaic cell is severely restricted by the working efficiency and the price of the photovoltaic cell. The generating efficiency of the crystalline silicon solar cell is often dependent on the working temperature of the cell, and the output power is reduced by 0.4-0.5% when the temperature is increased by 1 ℃. More than 80% of the energy reaching the surface of the solar cell is converted into heat, so that the working temperature of the solar cell is usually more than 50 ℃, even reaches 80 ℃ when the heat dissipation is poor, and further the working efficiency of the solar cell is seriously influenced.
The ground source heat pump system is used for extracting low-grade energy stored underground for human service by consuming a small amount of high-grade energy (electric energy). In winter, the temperature of the underground rock-soil body or the water body is higher than the temperature of the atmosphere, and the heat of the underground is extracted by the heat pump system to supply heat to users; in summer, the temperature of the underground rock-soil body or the water body is lower than the temperature of the atmosphere, and the heat in the room is absorbed through the heat pump circulation and then released back to the underground rock-soil body or the water body. Therefore, the ground source heat pump system has the advantages of high efficiency, energy conservation, safety, reliability, low operation cost and the like. However, when the ground source heat pump is operated for a long time, the soil temperature will be reduced, the unit operation performance is reduced, the problem of unbalanced cold and heat of the soil is caused, and even the system can not operate normally in serious cases.
Disclosure of Invention
The invention aims to solve the problems and provide a ground source heat pump coupling system based on photovoltaic and photo-thermal. Aiming at the condition that solar energy is sufficient in northern areas of China and the heat load in summer is often lower than the cold load in winter, the invention adopts a PV/T system on the basis of realizing the refrigeration and heat supply of a building by utilizing a ground source heat pump, and combines a solar photovoltaic panel and a heat collector. The PV/T system takes away the generated heat from the PV/T heat collector through a medium, and controls the working temperature of the solar cell, thereby more efficiently providing electric energy and being used for supplying power to the ground source heat pump unit and the water pump in the cold and heat source machine room. The heat taken away by the heat-conducting medium from the PV/T heat collector can be used for heating domestic hot water and storing heat in a cross-season manner, so that the utilization rate of solar energy is improved, and the problem of unbalanced cold and heat of ground source heat pump soil is solved.
The invention realizes the purpose through the following technical scheme:
a ground source heat pump coupling system based on photovoltaic photo-thermal comprises a grid-connected photovoltaic power generation system, a solar photo-thermal system and a ground source heat pump system.
The grid-connected photovoltaic power generation system comprises a PV/T heat collector 1, a photovoltaic controller 2, a storage battery 3, a photovoltaic inverter 4, an alternating current power distribution cabinet 5, a ground source heat pump unit and a machine room water pump. The photovoltaic controller 2 is connected with the PV/T heat collector 1, the storage battery 3 and the photovoltaic inverter 4; the direct current generated by the PV/T heat collector 1 is supplied to a photovoltaic inverter 4 through a photovoltaic controller 2 and is stored in a storage battery 3; the storage battery 3 supplies power to the photovoltaic inverter 4 through the photovoltaic controller 2; the photovoltaic inverter 4 is connected with a public power grid through an alternating current power distribution cabinet 5, and is supplied with voltage-regulated power through the alternating current power distribution cabinet 5.
The solar photo-thermal system comprises a PV/T heat collector 1, a heat storage water tank 6, an underground heat storage pipe 15, a first heat exchanger 7, a second heat exchanger 16, a first variable frequency pump 8, a second variable frequency pump 17, a third variable frequency pump 18 and a ground source heat pump unit; the PV/T heat collector 1 further comprises a photovoltaic module, a heat conducting plate, a medium coil and a heat insulating layer. The PV/T heat collector 1 is connected with the heat storage water tank 6 through a medium coil, a third variable frequency pump 18 and an adjusting valve are arranged on a liquid outlet pipeline of the heat storage water tank 6, and liquid outlet is adjusted by adjusting the frequency of the variable frequency pump or the opening of the adjusting valve; the heat storage water tank 6 is connected with the ground source heat pump unit evaporator 13 in parallel at the liquid inlet of the first heat exchanger 7 through a pipeline and is connected with the second heat exchanger 16 through a pipeline; a first variable frequency pump 8 and an electric regulating valve are arranged on a liquid inlet pipeline of the first heat exchanger 7, and liquid inlet is regulated by regulating the frequency of the variable frequency pump or the opening degree of the electric regulating valve; the second heat exchanger 16 is connected with the heat storage water tank 6 and the underground heat storage pipe 15 through pipelines, a second variable frequency pump 17 is arranged on a liquid inlet pipeline of the second heat exchanger 16 connected with the heat storage water tank 6, and liquid inlet is adjusted by adjusting the frequency of the variable frequency pump; and the underground heat storage pipe 15 is connected with the second heat exchanger 16 and the ground source heat pump unit condenser 11 and is controlled by a butterfly valve.
The ground source heat pump system comprises a ground source heat pump unit, an underground buried pipe 14, an underground heat storage pipe 15, a system tail end and a circulating water pump. The ground source heat pump unit also comprises a motor 9, a compressor 10, a condenser 11, a throttle valve 12 and an evaporator 13; the underground buried pipe 14 and the underground heat storage pipe 15 are connected in parallel at the liquid inlet of the ground source heat pump condenser 11.
Specifically, the photovoltaic module on the PV/T heat collector adopts crystalline silicon photovoltaic module, the PV/T heat collector is equipped with four quadrant photoelectric sensors, can follow the sunlight automatically and adjust the angle to the light strongest place.
Specifically, the support and the metal shell of the PV/T heat collector are all connected in an equipotential mode and grounded, and the support and the metal shell and the whole underground space form a common grounding grid.
Specifically, the medium coil is arranged on the back of the heat-conducting aluminum plate, an anti-freezing heat exchange working medium is arranged in the medium coil, and the heat exchange working medium absorbs heat on the PV/T heat collector through the heat-conducting aluminum plate and enters the heat storage water tank for heat exchange.
The invention has the beneficial effects that: 1) the invention adopts three heat sources: solar energy, geothermal energy and heat storage. The solar energy and the geothermal energy are green and environment-friendly renewable energy sources, so that the energy is saved, the emission is reduced, and the solar energy and the geothermal energy are economical and reliable; the heat storage is a special energy form, and the surplus solar energy in summer and transition seasons is stored in underground soil, so that the COP of the ground source heat pump for heating in winter is improved, and the problem of unbalanced cold and heat of the ground source heat pump soil is solved.
2) The invention adopts the PV/T heat collector, and the PV/T heat collector is a device which can simultaneously provide heat energy and electric energy, thereby greatly improving the utilization efficiency of solar energy. Compared with a photovoltaic system and a photothermal system with the same output, the solar photovoltaic system and the photothermal system have the advantages of higher solar energy utilization efficiency, longer service life, smaller occupied area, less investment recovery period and the like.
3) The invention supplies power and supplies heat by applying the photovoltaic photo-thermal technology on the basis of realizing the refrigeration and heat supply of the building by utilizing the ground source heat pump. Compared with the traditional water chilling unit and coal power generation modes, the invention reduces the operation cost, reduces the investment recovery period and has obvious economic benefit; reducing energy consumption and CO2The method improves the ecological environment and actively responds to national carbon peak-reaching and carbon-neutralizing policies.
Drawings
FIG. 1 is a schematic flow diagram of an example embodiment of the present invention;
FIG. 2 is a schematic view of a PV/T concentrator configuration.
In fig. 1: 1. the photovoltaic/T heat collector comprises a PV/T heat collector 2, a photovoltaic controller 3, a storage battery 4, a photovoltaic inverter 5, an alternating current power distribution cabinet 6, a heat storage water tank 7, a first heat exchanger 8, a first variable frequency pump 9, a motor 10, a compressor 11, a condenser 12, a throttle valve 13, an evaporator 14, an underground buried pipe 15, an underground heat storage pipe 16, a second heat exchanger 17, a second variable frequency pump 18 and a third variable frequency pump.
Detailed Description
In order to more fully express the technical scheme provided by the invention, the following further description is provided by specific implementation examples.
Referring to the attached drawings, a ground source heat pump coupling system based on photovoltaic and photo-thermal comprises a grid-connected photovoltaic power generation system, a solar photo-thermal system and a ground source heat pump system.
The grid-connected photovoltaic power generation system comprises a PV/T heat collector 1, a photovoltaic controller 2, a storage battery 3, a photovoltaic inverter 4, an alternating current power distribution cabinet 5, a ground source heat pump unit and a machine room water pump. The photovoltaic controller 2 is connected with the PV/T heat collector 1, the storage battery 3 and the photovoltaic inverter 4; the direct current generated by the PV/T heat collector 1 is supplied to a photovoltaic inverter 4 through a photovoltaic controller 2 and is stored in a storage battery 3; the storage battery 3 supplies power to the photovoltaic inverter 4 through the photovoltaic controller 2; the photovoltaic inverter 4 is connected with a public power grid through an alternating current power distribution cabinet 5, and is supplied with voltage-regulated power through the alternating current power distribution cabinet 5.
The solar photo-thermal system comprises a PV/T heat collector 1, a heat storage water tank 6, an underground heat storage pipe 15, a first heat exchanger 7, a second heat exchanger 16, a first variable frequency pump 8, a second variable frequency pump 17, a third variable frequency pump 18 and a ground source heat pump unit, wherein the PV/T heat collector 1 further comprises a photovoltaic assembly, a heat conducting plate, a medium coil and a heat insulating layer. The PV/T heat collector 1 is provided with a four-quadrant photoelectric sensor which can automatically adjust the angle to the strongest position along with sunlight, is connected with the heat storage water tank 6 through a medium coil, and is provided with a third variable frequency pump 18 and an adjusting valve on a liquid outlet pipeline of the heat storage water tank 6; the heat storage water tank 6 is connected with the ground source heat pump unit evaporator 13 in parallel at the liquid inlet of the first heat exchanger 7 through a pipeline and is connected with the second heat exchanger 16 through a pipeline; a first variable frequency pump 8 and an electric regulating valve are arranged on a liquid inlet pipeline of the first heat exchanger 7; the second heat exchanger 16 is connected with the heat storage water tank 6 and the underground heat storage pipe 15 through pipelines, and a second variable frequency pump 17 is arranged on a liquid inlet pipeline of the second heat exchanger 16 connected with the heat storage water tank 6; and the underground heat storage pipe 15 is connected with the second heat exchanger 16 and the ground source heat pump unit condenser 11 and is controlled by a butterfly valve.
The ground source heat pump system comprises a ground source heat pump unit, an underground buried pipe 14, an underground heat storage pipe 15, a system tail end and a circulating water pump. The ground source heat pump unit also comprises a motor 9, a compressor 10, a condenser 11, a throttle valve 12 and an evaporator 13; the underground buried pipe 14 and the underground heat storage pipe 15 are connected in parallel at the liquid inlet of the ground source heat pump condenser 11.
The operation modes and strategies provided by the present embodiment are as follows: and in summer, the ground source heat pump enters an air-conditioning refrigeration operation mode. When solar energy is sufficient, solar energy is utilized to supply power to the ground source heat pump unit and a motor of a machine room water pump, the electric energy converted from the surplus solar energy can be used for storage battery to store electricity, and a large amount of electricity can be sold to a public power grid after the storage battery is fully charged; because the ambient temperature is higher, the hot water load is reduced, and the solar energy can not only meet the requirement of domestic hot water, but also largely store heat in soil; the geothermal energy of the underground buried pipe is utilized to carry out air conditioning refrigeration through the ground source heat pump unit. When the solar energy is insufficient, the storage battery is utilized to assist the solar energy to supply power, and the insufficient electric quantity can be provided by a public power grid; because the heat load is smaller, the heat of the solar energy and the heat storage water tank can meet the requirement of heating domestic hot water; the geothermal energy of the underground buried pipe is utilized to carry out air conditioning refrigeration through the ground source heat pump unit.
For spring and autumn, the whole building adopts a free fresh air cooling mode, and the ground source heat pump unit does not need refrigeration and heat supply. When solar energy is sufficient, solar energy is utilized to supply power to the ground source heat pump unit and a motor of a machine room water pump, the electric energy converted from the surplus solar energy can be used for storage battery to store electricity, and the electricity can be sold to a public power grid after the storage battery is fully charged; the heat converted by the solar energy is used for heating domestic hot water, and the surplus solar energy can be used for storing soil heat. When the solar energy is insufficient, the storage battery is utilized to assist the solar energy to supply power, and the insufficient electric quantity can be provided by a public power grid; the solar energy is assisted by the ground source heat pump to heat the domestic hot water.
And for winter, the ground source heat pump enters a heating operation mode. When solar energy is sufficient, solar energy is utilized to supply power to the ground source heat pump unit and a motor of a machine room water pump, and the surplus electric energy converted from the solar energy is completely used for storage of a storage battery; the heat converted by the solar energy is used for heating domestic hot water, and the abundant heat can be directly used for heating buildings. When the solar energy is insufficient, the storage battery is utilized to assist the solar energy to supply power, and the insufficient electric quantity can be provided by a public power grid; the heat converted by the solar energy is completely used for heating domestic hot water, and insufficient heat is provided by the ground source heat pump. But the auxiliary heating capacity of the ground source heat pump is the largest, and meanwhile, the ground source heat pump unit also needs to supply heat to the building, so that the heat energy of the underground buried pipe heat storage in summer and transition seasons is used for supplying heat to the building through the ground source heat pump unit.
The working process and principle provided by the embodiment are as follows: when solar energy is sufficient, in the aspect of solar photovoltaic power generation application, a photovoltaic module on a PV/T heat collector 1 converts solar energy into direct current and transmits the direct current to a photovoltaic controller 2, then the direct current is transmitted to a storage battery 3 for storage and standby through the photovoltaic controller 2, on the other hand, the direct current is transmitted to a photovoltaic inverter 4 and converted into alternating current, the alternating current is subjected to voltage regulation through an alternating current power distribution cabinet 5 and then is distributed to a machine room water pump and a motor 9 of a ground source heat pump unit for power supply, and the alternating current power distribution cabinet 5 can sell power to a public power grid under the condition that the storage battery 3 is fully charged; in the aspect of solar photo-thermal application, heat converted by the PV/T heat collector 1 is transferred to the heat storage water tank 6 through the third variable frequency pump 18 by using a medium, and then is subjected to heat exchange through the first heat exchanger 7 by the first variable frequency pump 8 to supply hot water to a user, abundant heat in summer can be subjected to heat exchange through the second variable frequency pump 17 through the second heat exchanger 16 to store heat to the underground heat storage pipe 15, and abundant heat in winter can be directly used for heating buildings through the adjusting valve; in the aspect of ground source heat pump refrigeration and heat supply application, a valve connecting an underground heat storage pipe 15 and a second heat exchanger 16 is opened in summer and transitional seasons, the valve connecting the underground heat storage pipe 15 and a condenser 11 is closed, the ground source heat pump unit directly utilizes an underground buried pipe 14 to exchange heat with the condenser 11, refrigeration and heat supply are carried out on a building through a refrigeration cycle utilization evaporator 13, the valve connecting the underground heat storage pipe 15 and the second heat exchanger 16 is closed in winter, the valve connecting the underground heat storage pipe 15 and the condenser 11 is opened, the ground source heat pump unit can utilize the underground buried pipe 14 and the underground heat storage pipe 15 to exchange heat with the condenser 11, and refrigeration and heat supply are carried out on the building through the refrigeration cycle utilization evaporator 13.
When the solar energy is insufficient, in the aspect of solar photovoltaic power generation application, the storage battery 3 is utilized to assist direct current converted by a photovoltaic module on the PV/T heat collector 1 to be transmitted to the photovoltaic controller 2, then the direct current is transmitted to the photovoltaic inverter 4 through the photovoltaic controller 2 to be converted into alternating current, the alternating current is subjected to voltage regulation through the alternating current power distribution cabinet 5 and then is distributed to the water pump of a machine room and the motor 9 of the ground source heat pump unit for power supply, and under the condition that the power supply does not meet the requirement, the alternating current power distribution cabinet 5 is used for purchasing power for the public power grid for supplement; in the aspect of solar photo-thermal application, the heat converted by the PV/T heat collector 1 is transferred to the heat storage water tank 6 by a medium through the third variable frequency pump 18, then is subjected to heat exchange through the first heat exchanger 7 by the first variable frequency pump 8, and then is supplied to a user for supplying hot water, and is supplemented to the first heat exchanger 7 through the ground source heat pump evaporator 13 under the condition that the heat supply does not meet the requirement; in the aspect of ground source heat pump refrigeration and heat supply application, the valve connecting the underground heat storage pipe 15 and the second heat exchanger 16 is closed, the valve connecting the underground heat storage pipe 15 and the condenser 11 is opened, the ground source heat pump unit can exchange heat with the condenser 11 by utilizing the underground buried pipe 14 and the underground heat storage pipe 15, and the evaporator 13 is utilized for refrigeration and heat supply to the building through refrigeration cycle.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.