PV / T coupling ground source heat pump combined cooling heating and power system model and modeling method

Abstract

The invention provides a PV / T coupling ground source heat pump combined cooling heating and power system model and a modeling method, and the system is characterized in that the energy-saving efficiency of a PV / T coupling ground source heat pump system is improved through an alternate operation mode for regions with sufficient annual irradiation and long heating time. According to the system model and the modeling method provided by the invention, the energy-saving efficiency of the system can be improved, important energy-saving evaluation data such as the energy efficiency ratio, the heat collection / refrigerating capacity, the power generation efficiency and the power generation capacity of the PV / T coupling ground source heat pump combined cooling heating and power supply system can be obtained, and whether thermal unbalance occurs in soil in the long-term operation process of the heat pump or not is quantitatively judged; whether a soil heat recharge system needs to be set or not is judged, and an efficient solution is provided for solving the problem that the energy-saving and carbon-reducing effects, the initial investment and the internal yield of a zero-carbon building scheme cannot be measured and calculated in the early-stage scheme design.

Description

Technical Field

[0001] The present invention relates to a PV / T coupled ground source heat pump cooling, heating and power trigeneration system model and a modeling method, and relates to the technical field of heating system modeling and simulation. Background Art

[0002] In recent years, my country has actively promoted the green and low-carbon transformation of industrial parks. The main way to create zero-carbon industrial parks / buildings is to consider vigorously developing renewable energy, using photovoltaics, air energy, geothermal energy, etc. to provide clean energy for industrial parks / buildings and achieve green and low-carbon substitution.

[0003] PV / T technology improves the efficiency of photovoltaic power generation and outputs heat energy by laying flow channels on the back of photovoltaic cells and cooling photovoltaic cell groups through circulating media, while meeting users' needs for high-quality electricity and low-quality heat energy. However, the performance of PV / T systems is significantly affected by weather conditions and lacks the ability to provide stable heating. Therefore, it is usually combined with ground-source heat pump technology, which can provide stable energy and is less restricted by geographical conditions, to achieve complementary advantages and provide heating or hot water around the clock. In addition, PV / T as a low-temperature heat source can not only reduce the length of buried pipes and improve the energy efficiency of the entire heating system, but also re-inject heat into the soil in spring, summer and autumn to solve the difficult soil temperature imbalance problem caused by the long-term operation of ground-source heat pumps.

[0004] The PV / T coupled ground source system in the current public technical literature focuses on the source side series system. This combination is applied to areas with sufficient radiation throughout the year and long heating time, and the energy saving effect is not ideal. In addition, there is currently no public technical process flow and simulation model that can achieve trigeneration of heat and electricity for the PV / T coupled ground source heat pump system in this scenario. There are no targeted technical parameters and solutions for reference from the early design to construction. Therefore, in the early design of the scheme, the energy efficiency ratio, heat collection / cooling capacity, power generation efficiency and power generation of the trigeneration system, important energy-saving evaluation data such as power efficiency ratio, heat collection / cooling capacity, power generation efficiency and power generation, whether the soil will have thermal imbalance during the long-term operation of the heat pump, and whether the PV / T heat recharge system needs to be set up, cannot be determined, resulting in the energy saving and carbon reduction effect, initial investment and internal rate of return of the zero-carbon building scheme cannot be calculated, and the scheme decision cannot be completed. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, in view of the above problems, the purpose of the present invention is to provide a PV / T coupled ground source heat pump cooling, heating and power trigeneration system model and modeling method, which can effectively improve energy saving efficiency and realize hourly simulation of the PV / T coupled ground source heat pump cooling, heating and power trigeneration system model, and provide a basis and important process data reference for the design and construction of the system.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0007] In the first aspect, the present invention provides a PV / T coupled ground source heat pump trigeneration system model, the system includes a meteorological parameter module, a PV / T collector, a PV / T circulating water pump, a heating / cooling terminal building load, a ground source heat pump unit, a buried pipe heat exchanger, a water pump assembly, a valve assembly, a heating / cold season time controller, a hot water storage tank, an inverter and a controller. The heating subsystem, the cooling subsystem, the power generation subsystem and the control subsystem are respectively constructed by combining the above-mentioned devices, and the switching of the cooling and heating modes is realized by controlling the start and stop and the flow of the valve assembly and the water pump assembly.

[0008] Furthermore, the heating subsystem is implemented by a meteorological parameter module, a PV / T collector, a PV / T circulating water pump, a heating / cooling terminal building load, a ground source heat pump unit, a buried pipe heat exchanger, a water pump assembly, a valve assembly, a heating / cooling season time controller and a hot water storage tank, wherein the meteorological parameter module is connected to the PV / T collector, the PV / T circulating water pump is connected to the PV / T collector and the hot water storage tank, the load side outlet of the hot water storage tank is connected to the heating / cooling terminal building load through a first mixing valve, and the heating / cooling terminal building load is connected to the The cold side inlet of the hot water storage tank; the ground source side outlet of the ground source heat pump unit is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, and the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit; the load side outlet of the ground source heat pump unit is connected to the hot water storage tank through the second diverter valve, and the hot water storage tank is connected to the inlet side of the hot water storage tank through the first mixing valve, the load side circulating water pump, the heating / cooling terminal building load, and the first diverter valve; the heat source outlet of the hot water storage tank is connected to the load side inlet of the ground source heat pump unit through the third diverter valve, the circulating water pump, and the second mixing valve.

[0009] Furthermore, the refrigeration subsystem is implemented by a heating / cooling terminal building load, a ground source heat pump unit, a water pump assembly, a valve assembly and a heating / cooling season time controller, wherein the ground source side outlet of the ground source heat pump unit is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit, the load side outlet of the ground source heat pump unit is connected to the first mixing valve through the second diverter valve, and the first mixing valve is connected to the load side inlet of the ground source heat pump unit through the load side circulating water pump, the heating / cooling terminal building load, the first diverter valve and the second mixing valve.

[0010] Furthermore, the power generation subsystem is implemented by a meteorological parameter module, a PV / T collector and an inverter. The meteorological parameter module is connected to the PV / T collector, and the PV / T collector is connected to the inverter for outputting electric energy.

[0011] Furthermore, the control subsystem controls the start and stop and flow of the valve assembly and the water pump assembly through different controllers to achieve the switching of the cooling and heating modes. The specific process includes one or more of the following controls:

[0012] Control PV / T circulating water pump: The self-feedback temperature difference controller is connected to the heating / cooling terminal building load, the hot water storage tank, the PV / T collector and the PV / T circulating water pump, and transmits the measured outlet temperature of the hot water storage tank heat source and the outlet water temperature of the PV / T collector to the self-feedback temperature difference controller. The self-feedback temperature difference controller transmits the control signal to the PV / T circulating water pump for control based on the obtained temperature value;

[0013] Control the temperature of the hot water storage tank: The water tank temperature controller is connected to the hot water storage tank to monitor the outlet water temperature on the load side of the hot water storage tank. The outlet water temperature is combined with the heating / cooling time and the heating / cooling terminal building load to generate control instructions through calculation. The control instructions are used to control the circulating water pump on the ground source side, the circulating water pump on the load side, and the start and stop of the circulating water pump to achieve switching between different heating modes;

[0014] Control the third diverter valve: The third diverter valve controller is connected to the water tank temperature controller, the heating / cooling season time controller and the heating / cooling terminal building load. After calculation and considering that if the PV / T circulating water pump meets the start-up conditions and the ground source heat pump unit also meets the start-up conditions, the third diverter valve generates a control instruction for control according to the principle determined by the ratio of the circulating water pump flow rate to the PV / T circulating water pump flow rate;

[0015] Controlling the second diverter valve: the second diverter valve controller is connected to the heating / cooling season time controller, and generates a control signal according to the heating / cooling season time controller;

[0016] Control the first diverter valve: The first diverter valve controller is connected to the load-side circulating water pump, the first mixing valve, the hot water storage tank, the heating / cold season time controller and the heating / cooling terminal building load, and generates control conditions based on whether the heating conditions are met and whether the terminal load outlet temperature is higher than the preset temperature.

[0017] Furthermore, the heating operation modes of the heating subsystem include PV / T independent heating mode, mixed heating mode and ground source heat pump independent heating mode, wherein:

[0018] In the PV / T independent heating mode, the operation process of the heating subsystem is as follows: the hot side outlet of the water storage tank is connected to the third diverter valve, the outlet of the third diverter valve is connected to the inlet of the PV / T collector through the PV / T circulating water pump, and the outlet of the PV / T collector is connected to the hot side inlet of the water storage tank through the first mixing valve; the cold side outlet of the water storage tank is connected to the load side circulating water pump, the outlet of the load side circulating water pump is connected to the terminal building load through the first mixing valve, and the terminal building load is connected to the cold side inlet of the water storage tank through the first diverter valve;

[0019] In the hybrid heating mode, the operation process of the heating subsystem is as follows: the hot side outlet of the hot water storage tank is connected to the third diverter valve, and the outlet ① of the third diverter valve is connected to the inlet of the PV / T collector through the PV / T circulating water pump, and the outlet of the PV / T collector is connected to the hot side inlet of the hot water storage tank through the first mixing valve; the hot side outlet of the hot water storage tank is connected to the third diverter valve, and the outlet ① of the third diverter valve is connected to the load side inlet of the ground source heat pump through the circulating water pump and the second mixing valve, and the load side outlet of the ground source heat pump is connected to the hot side inlet of the hot water storage tank through the second diverter valve and the third mixing valve; the ground source side outlet of the ground source heat pump is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, and the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump; the cold side outlet of the hot water storage tank is connected to the load side circulating water pump, and the outlet of the load side circulating water pump is connected to the terminal building load through the first mixing valve, and the terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve;

[0020] In the ground source heat pump separate heating mode, the operation process of the heating subsystem is as follows: the ground source side outlet of the ground source heat pump unit is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, and the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit; the cold side outlet of the hot water storage tank is connected to the load side circulating water pump, and the outlet of the load side circulating water pump is connected to the heating\cooling terminal building load through the first mixing valve, and the heating\cooling terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve.

[0021] In a second aspect, the present invention further provides a modeling method for a PV / T coupled ground source heat pump cooling, heating and power trigeneration system model, comprising:

[0022] Setting heating / cooling terminal building load: The building cooling and heating terminal building load calculation software sets the building's attributes and usage, and considers the influencing factors using the harmonic response method;

[0023] Set meteorological parameter inputs, including outdoor temperature, humidity, wind speed, and solar radiation intensity;

[0024] Set the relevant parameters of the PV / T collector, including the PV / T collector area, the PV / T module tilt angle, the PV / T module heat collection efficiency factor, the medium fluid heat capacity, the PV / T collector plate emissivity, the reference temperature of the photovoltaic part power generation efficiency, the photovoltaic power generation efficiency in the PV / T module at the reference temperature, the photovoltaic power generation efficiency correction temperature coefficient, the packaging coefficient, the PV / T module bottom and edge heat loss coefficient and the number of glass covers;

[0025] Set the parameters of the ground source heat pump unit, including the ground source heat pump rated cooling / heating capacity, rated flow, cooling / heating performance coefficient, heating and cooling mode, rated evaporator and condenser flow;

[0026] Set the parameters of the underground heat exchanger, including the vertical buried pipe length and diameter, and U-shaped pipe parameters;

[0027] Set the parameters of the hot water storage tank, including the volume of the hot water storage tank, the outer wall temperature of the hot water storage tank, the heat capacity and density of the medium in the water tank, the heat loss coefficient per unit area of ​​the hot water storage tank, the node height, the auxiliary heating mode, the set heating temperature and the dead zone temperature difference of the heating water tank;

[0028] Set water pump parameters, including water pump flow, head and efficiency, and start and stop control signals;

[0029] Set the control mode of water pump operation;

[0030] Setting the heating / cooling time, wherein the heating / cooling time is determined according to the regulations and climate conditions of the simulated area;

[0031] Set the control mode of the valve assembly.

[0032] Furthermore, the water pump parameters are set, including the water pump flow, head, efficiency and start / stop control signals. The specific process is as follows:

[0033] The circulating water flow rate of the PV / T circulating water pump is determined according to the total area of ​​PV / T and the unit area flow rate of the working fluid:

[0034] G=A indirect ×m A ;

[0035] Where G is the flow rate of PV / T circulating water pump; A indirect =PV / T total area; m A is the flow rate per unit area of ​​the working fluid;

[0036] The circulating water flow rate of the circulating water pump on the load side is determined according to the larger value of the cold and hot terminal building loads of the designed building and the supply and return water temperature difference on the load side of the terminal building:

[0037]

[0038] Among them, G is the flow rate of the circulating water pump on the load side; Q is the maximum value of the building's cooling and heating load; Δt is the temperature difference between the supply and return water temperatures on the design load side; c is the specific heat capacity of water;

[0039] The circulating water flow rate of the circulating water pump on the ground source side is determined according to the larger value of the cold and hot terminal building load of the designed building, the energy efficiency ratio of the ground source heat pump unit and the temperature difference between the supply and return water on the ground source side:

[0040]

[0041] Among them, G is the flow rate of the circulating water pump on the ground source side; Q is the maximum value of the building's cooling and heating load; Δt is the designed temperature difference between the supply and return water temperatures on the ground source side; c is the specific heat capacity of water;

[0042] The pump power corresponding to the circulating water pump is determined according to the corresponding pump flow, head and efficiency:

[0043]

[0044] Among them, N is the pump power; G is the pump flow; H is the pump head; η is the pump efficiency.

[0045] Furthermore, the water pump operation control mode is set, and the specific implementation process is as follows:

[0046] The PV / T circulating water pump operation control part adopts temperature difference control. The start condition is: when the heating demand is received during the heating period and the difference between the outlet water temperature of the PV / T collector and the outlet temperature of the heat source of the hot water storage tank is greater than 8°C, it is completed by using a differential controller: if the controller is currently in the on state, then:

[0047]

[0048] If the controller is currently in the off state, then:

[0049]

[0050] Where, γ is the output signal; T h is the input high temperature, which is represented by the outlet water temperature of the PV / T collector in this system; T l The input low temperature is represented by the outlet water temperature of the water tank flowing to PV / T in this system; ΔT h is the upper limit of the dead zone; ΔT l The lower limit of the dead zone; 0 means the closing command; 1 means the opening command;

[0051] Conditions for starting the ground source side circulating water pump: receiving hourly heating and cooling load demands during the heating / cooling period and the water tank temperature is lower than 58°C during the heating period;

[0052] Load-side circulating water pump start-up conditions: receiving hourly heating and cooling load demands during the heating / cooling period;

[0053] Conditions for starting the circulating water pump: When the hourly heat load demand is received during the heating period and the water tank temperature is lower than 58°C when PV / T is used for heating alone during the heating period.

[0054] Due to the adoption of the above technical scheme, the present invention has the following characteristics: 1. The present invention is characterized in that for areas with sufficient radiation throughout the year and long heating time, the energy-saving efficiency of the PV / T coupled ground source heat pump system is improved through an alternating operation mode. The alternating operation mode is to use PV / T to directly heat users during the day, and use ground source heat pumps for heating at night or when other PV / T cannot meet the heating conditions, thereby reducing the continuous operation time of the ground source heat pump system. The soil temperature field can be restored to a certain extent when PV / T is used for heating during the day, thereby ensuring that the ground source heat pump will not show a significant decline in operating efficiency under long-term operation, thereby improving the energy-saving efficiency of the entire coupling system and reducing energy consumption. 2. The present invention can obtain important energy-saving evaluation data such as the energy efficiency ratio, heat collection / cooling capacity, power generation efficiency and power generation of the PV / T coupled ground source heat pump trigeneration system model, quantitatively judge whether the soil will have thermal imbalance during the long-term operation of the heat pump, and whether the soil heat recharge system needs to be set up, providing an efficient solution to the problem that the energy-saving and carbon-reduction effect, initial investment and internal rate of return of the zero-carbon building scheme in the early scheme design cannot be calculated. In summary, the present invention can be widely used in the establishment of a PV / T coupled ground source heat pump trigeneration system model. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0056] Figure 1 A schematic diagram of the structure of an embodiment of the present invention;

[0057] Figure 2 A diagram of local outdoor temperature throughout the year and solar radiation intensity on an inclined surface according to an embodiment of the present invention;

[0058] Figure 3 The simulation result diagram of the real-time PV / T heat collection, power generation, and the annual cumulative heat collection and power generation of the embodiment of the present invention;

[0059] Figure 4 This is a simulation result diagram of the annual operating power of the ground source heat pump unit and water pump according to an embodiment of the present invention;

[0060] Figure 5A real-time simulation result diagram of the annual heating / cooling power and energy consumption of the ground source heat pump unit and the hot water storage tank according to an embodiment of the present invention;

[0061] Figure 6 This is a graph showing the real-time simulation results of the inlet and outlet temperatures of the buried pipes and the average soil temperature throughout the year for the ground source heat pump according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0063] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0064] Since the PV / T coupled ground source system in the current public technical literature focuses on the source side series system, this combination is applied to areas with sufficient radiation throughout the year and long heating time, and the energy saving effect is not ideal. The PV / T coupled ground source heat pump trigeneration system model and modeling method provided by the present invention include a meteorological parameter module, a PV / T collector, a PV / T circulating water pump, a heating / cooling terminal building load, a ground source heat pump unit, a buried pipe heat exchanger, a water pump assembly, a valve assembly, a heating / cold season time controller, a hot water storage tank, an inverter and a controller. The heating subsystem, the cooling subsystem, the power generation subsystem and the control subsystem are constructed by combining the above devices. The switching of the cooling and heating modes is realized by controlling the start and stop and flow of the valve assembly and the water pump assembly. Therefore, the present invention can improve the energy-saving efficiency of the system and obtain important energy-saving evaluation data such as the energy efficiency ratio of the PV / T coupled ground source heat pump trigeneration system model, heat collection / cooling capacity, power generation efficiency and power generation. It can also quantitatively determine whether thermal imbalance will occur in the soil during the long-term operation of the heat pump and whether a soil heat reinjection system needs to be set up, thereby providing an efficient solution to the difficult problem of the inability to calculate the energy-saving and carbon-reduction effects, initial investment and internal rate of return of zero-carbon building solutions in the early stage of solution design.

[0065] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0066] The PV / T coupled ground source heat pump trigeneration system model provided in this embodiment includes a meteorological parameter module, a PV / T collector, a PV / T circulating water pump, a heating / cooling terminal building load, a ground source heat pump unit, a buried pipe heat exchanger, a water pump assembly, a valve assembly, a heating / cold season time controller, a hot water storage tank, an inverter and a controller. The heating subsystem, the cooling subsystem, the power generation subsystem and the control subsystem are respectively constructed by combining the above devices, and the switching of the cooling and heating modes is realized by controlling the start and stop and flow of the valve assembly and the water pump assembly.

[0067] In a preferred embodiment, the meteorological parameter module is used to set meteorological parameters. The PV / T collector is used to set the PV / T area, the PV / T installation inclination, the emissivity and absorptivity of the absorption plate in the PV / T collector. The ground source heat pump unit is used to set the rated cooling and heating capacity, rated flow rate, nominal cooling and heating performance coefficient, and rated evaporator and condenser flow rates of the ground source heat pump. The buried pipe heat exchanger is used to set the length and diameter of the vertical buried pipe and the U-shaped pipe parameters of the buried pipe. The heating / cold season time controller is used to set the heating / cooling time. The water pump assembly is used to set the water pump flow rate and power of the PV / T collector circulation side, the terminal building load side, and the ground source side circulation. The water pump assembly includes a PV / T circulation water pump, a load side circulation water pump, a ground source side circulation water pump, and a circulation water pump. The valve assembly is used to set the valve switch, including a first diverter valve, a second diverter valve, a third diverter valve, a first mixing valve, a second mixing valve, and a third mixing valve.

[0068] In a preferred embodiment, the heating subsystem is used to trigger the switching logic of the three heating modes by monitoring the solar radiation intensity and the outlet water temperature of the hot water storage tank, and then determine the performance parameters of each system component in the corresponding mode. The specific implementation process is as follows: the heating subsystem is implemented by the meteorological parameter module, PV / T collector, PV / T circulating water pump, heating / cooling terminal building load, ground source heat pump unit, buried pipe heat exchanger, water pump assembly, valve assembly, heating / cooling season time controller and hot water storage tank. The meteorological parameter module is connected to the PV / T collector to transfer the meteorological parameters to the PV / T assembly. The PV / T circulating water pump is connected to the PV / T collector and the hot water storage tank for heat transfer. The PV / T circulating water pump transfers the temperature and flow of the heat transfer medium to the PV / T collector. The PV / T collector is connected to the lower coil of the hot water storage tank to transfer the heat to the hot water storage tank. The hot water storage tank part is used to set the hot water storage tank volume, the hot water storage tank heat loss coefficient and the auxiliary heating mode. The load side outlet of the hot water storage tank is connected to the heating / cooling terminal building load through the first mixing valve. The terminal building load is used to set the heating / cooling terminal building load parameters. The terminal building load parameters are transmitted through the terminal building load loading file connected to the terminal building load. The heating / cooling terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve; the ground source side outlet of the ground source heat pump unit is connected to the inlet of the ground pipe heat exchanger through the ground source side circulating water pump, and the outlet of the ground pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit, completing the heat flow transfer cycle on the ground source side of the heat pump unit. The load side outlet of the ground source heat pump unit is connected to the hot water tank through the second diverter valve, and the hot water tank is connected to the inlet side of the hot water tank through the first mixing valve, the load side circulating water pump, the heating / cooling terminal building load, and the first diverter valve; the heat source outlet of the hot water tank is connected to the load side inlet of the ground source heat pump through the third diverter valve, the circulating water pump, and the second mixing valve, completing the load side heat flow transfer cycle of the heat pump unit, wherein the graphic and data output device is connected to the meteorological parameter module, PV / T collector, heat pump unit, ground source side circulating water pump, load side circulating water pump, circulating water pump and hot water tank part, and is used to output the annual outdoor temperature, inclined surface solar irradiance, PV / T collection rate, annual cumulative collection, heat pump unit, water pump operating power and energy consumption, heat pump unit heating capacity, heating performance coefficient, load side water outlet temperature of the hot water tank, heating power and cumulative heat supply, and buried pipe inlet and outlet temperatures.

[0069] In a preferred embodiment, the refrigeration subsystem is used to adjust the refrigeration capacity of the ground source heat pump system according to the user terminal load so as to determine the performance parameters of each system component. The specific implementation process is as follows: the refrigeration subsystem is implemented by the heating / cooling terminal building load, the ground source heat pump unit, the water pump assembly, the valve assembly and the heating / cooling season time controller, wherein the heating / cooling terminal building load parameter is transmitted through the terminal building load loading file connected to the heating / cooling terminal building load. The ground source side outlet of the ground source heat pump unit is connected to the inlet of the ground pipe heat exchanger through the ground source side circulating water pump, the outlet of the ground pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit, the load side outlet of the ground source heat pump unit is connected to the first mixing valve through the second diverter valve, and the first mixing valve is connected to the load side inlet of the ground source heat pump unit through the load side circulating water pump, the heating / cooling terminal building load, the first diverter valve and the second mixing valve. Among them, the graphic and data output device is connected to the ground source heat pump unit, the ground source side circulating water pump, and the buried pipe heat exchanger, and outputs the heat pump unit, the water pump operating power and energy consumption, the heat pump unit cooling capacity, the refrigeration performance coefficient, the buried pipe inlet and outlet temperatures, etc.

[0070] In a preferred embodiment, the power generation subsystem is used to determine the power generation that the PV / T module can provide to the user terminal according to the solar radiation intensity, wind speed and ambient temperature. The specific implementation process is as follows: the power generation subsystem is implemented through a meteorological parameter module, a PV / T collector and an inverter. The meteorological parameter module is used to set meteorological parameters. The PV / T collector is used to set the benchmark power generation efficiency, the temperature corresponding to the benchmark power generation efficiency, the emissivity of the photovoltaic panel, and the temperature effect factor on the power generation efficiency. The inverter part is used to set the maximum output power and inverter efficiency. The graphic and data output device is used to set the PV / T power generation power and the annual cumulative power generation. Among them, the meteorological parameter module imports the meteorological parameters into the PV / T collector, and the photovoltaic module in the PV / T collector converts solar energy into electrical energy. Its outlet is connected to the inverter part. The inverter part converts the direct current generated by the photovoltaic module into alternating current so that it can be incorporated into the power grid or directly used by users.

[0071] In a preferred embodiment, the control subsystem includes PV / T circulating water pump control, water tank temperature control, third diverter valve control, second diverter valve control and first diverter valve control, wherein the control subsystem is used to monitor the outlet water temperature of the hot water storage tank, and calculates and generates control instructions based on the outlet water temperature, the heating / cooling time, the outlet water temperature of the PV / T collector, the solar radiation intensity, the difference between the outlet temperature of the water tank heat source and the cold and hot terminal building loads. The control instructions are used to control the start and stop and flow of the valve assembly and the water pump. The control instructions are calculated based on the heating / cooling time and the cold and hot terminal building loads, and the graphic and data output device outputs the control instructions to control the start and stop and flow of the valve assembly and the water pump, which is used for switching between cooling and three heating modes.

[0072] Furthermore, PV / T circulating water pump control: the self-feedback temperature difference controller is connected to the cold and hot terminal building loads, the lower coil of the hot water storage tank, the PV / T collector and the collector water pump, and the outlet temperature of the hot water storage tank heat source and the outlet water temperature of the PV / T collector are transmitted to the controller, and the controller transmits the control signal to the PV / T circulating water pump.

[0073] Furthermore, water tank temperature control: the water tank temperature controller is connected to the hot water storage tank to monitor the outlet water temperature on the load side of the hot water storage tank. The outlet water temperature is combined with the heating / cooling time and the cold and hot terminal building loads to generate control instructions after calculation. The control instructions are used to control the ground source side circulating water pump, the load side circulating water pump and the start and stop of the circulating water pump to switch between three different heating modes.

[0074] Furthermore, the third diverter valve controls: the third diverter valve controller is connected to the water tank temperature controller according to the heating / cooling time and the cold and hot terminal building loads. After calculation and considering that the PV / T circulating water pump meets the start-up conditions and the heat pump unit also meets the start-up conditions, the diverter valve generates a control instruction based on the principle determined by the ratio of the circulating water pump flow rate to the upper PV / T circulating water pump flow rate.

[0075] Further, the second diverter valve controls: the second diverter valve controller is connected to the heating / cooling time, and generates a control signal according to the heating / cooling season time controller.

[0076] Furthermore, the first diverter valve controls: the first diverter valve controller is connected to the load side circulating water pump, the first mixing valve, the hot water storage pump, the heating / cooling time, and the cold and hot terminal building loads, and generates control conditions based on whether the heating conditions are met and whether the terminal load outlet temperature is higher than 55°C.

[0077] Furthermore, the heating operation modes of the heating subsystem include PV / T independent heating mode, mixed heating mode and ground source heat pump independent heating mode, wherein:

[0078] In the PV / T independent heating mode, the operation process of the heating subsystem is as follows: the hot side outlet of the water storage tank is connected to the third diverter valve, the ① outlet of the third diverter valve is connected to the PV / T collector inlet through the PV / T circulating water pump, and the PV / T collector outlet is connected to the hot side inlet of the water storage tank through the first mixing valve; the cold side outlet of the water storage tank is connected to the load side circulating water pump, the outlet of the load side circulating water pump is connected to the terminal building load through the first mixing valve, and the terminal building load is connected to the cold side inlet of the water storage tank through the first diverter valve.

[0079] In the hybrid heating mode, the operation process of the heating subsystem is as follows: the hot side outlet of the hot water storage tank is connected to the third diverter valve, the outlet ① of the third diverter valve is connected to the inlet of the PV / T collector through the PV / T circulating water pump, and the outlet of the PV / T collector is connected to the hot side inlet of the hot water storage tank through the first mixing valve; the hot side outlet of the hot water storage tank is connected to the third diverter valve, the outlet ① of the third diverter valve is connected to the load side inlet of the ground source heat pump through the circulating water pump and the second mixing valve, and the load side outlet of the ground source heat pump is connected to the hot side inlet of the hot water storage tank through the second diverter valve and the third mixing valve; the ground source side outlet of the ground source heat pump is connected to the inlet of the ground pipe heat exchanger through the ground source side circulating water pump, and the outlet of the ground pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump. The cold side outlet of the hot water storage tank is connected to the load side circulating water pump, the outlet of the load side circulating water pump is connected to the terminal building load through the first mixing valve, and the terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve.

[0080] In the ground source heat pump heating mode, the operation process of the heating subsystem is as follows: the ground source side outlet of the ground source heat pump unit is connected to the ground pipe heat exchanger inlet through the ground source side circulating water pump, and the ground pipe heat exchanger outlet is connected to the ground source side inlet of the ground source heat pump unit. The cold side outlet of the hot water storage tank is connected to the load side circulating water pump, and the outlet of the load side circulating water pump is connected to the heating / cooling terminal building load through the first mixing valve, and the heating / cooling terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve.

[0081] This embodiment also provides a modeling method for a PV / T coupled ground source heat pump combined heating and cooling power trigeneration system model, which is applied to a PV / T coupled ground source heat pump combined heating and cooling power trigeneration system model. The modeling method for a PV / T coupled ground source heat pump combined heating and cooling power trigeneration system model provided in this embodiment includes:

[0082] S1. Set the heating / cooling terminal building load.

[0083] In this embodiment, the heating / cooling terminal building load is calculated based on the building cooling and heating terminal building load calculation software: the building cooling and heating terminal building load calculation software sets the building's properties (such as population density, enclosure structure parameters, etc.) and usage, and considers the influence of various factors (such as outdoor temperature changes, solar radiation, etc.), and uses the harmonic response method to calculate the heating / cooling terminal building load.

[0084] S2. Set the meteorological parameter input part.

[0085] In this embodiment, the meteorological parameter input part is set: the meteorological parameter file of a certain area used is generated by Meteonorm software, including outdoor temperature, humidity, wind speed, and solar radiation intensity.

[0086] S3. Set the PV / T collector.

[0087] In this embodiment, setting the PV / T collector includes setting the total area of ​​the PV / T component, the inclination angle of the PV / T component, the thermal collection efficiency factor of the PV / T component, the heat capacity of the dielectric fluid, the emissivity of the PV / T collector plate, the reference temperature of the photovoltaic part power generation efficiency, the photovoltaic power generation efficiency in the PV / T component at the reference temperature, the photovoltaic power generation efficiency correction temperature coefficient, the packaging coefficient, the heat loss coefficient of the bottom and edge of the PV / T component and the number of glass cover plates.

[0088] Furthermore, the PV / T collector area is determined based on the total area of ​​the direct system collector, the total heat loss coefficient of the collector, and the heat transfer coefficient of the heat exchanger, and the expression is:

[0089]

[0090] Among them, A indirect A is PV / T total area; c is the total area of ​​direct system PV / T, m 2 ; U L is the total heat loss coefficient of the collector, W / (m 2 ℃); U hx is the heat transfer coefficient of the heat exchanger, W / (m 2 ℃); A hx is the heat exchange area of ​​the indirect system heat exchanger, m 2 .

[0091] Direct system PV / T total area A c It is determined based on the total heating terminal building load, solar energy guarantee rate, annual average daily solar radiation on the local PV / T collector lighting surface, average heat collection efficiency of PV / T collector and heat loss rate of pipeline and heat storage device. The expression is as follows:

[0092]

[0093] Among them, A c is the total area of ​​direct system PV / T, m 2 ;Q J Design heat load for the solar collector system, kW; J T is the annual average daily solar radiation intensity on the local collector lighting surface (the annual integral of the radiation intensity is calculated and then divided by 365); f is the solar energy guarantee rate; η cd is the average collector efficiency based on the total area, determined according to the product parameters provided by the manufacturer; η L is the heat loss rate of pipelines and heat storage devices.

[0094] S4. Set the ground source heat pump unit. The ground source heat pump unit is used to set the parameters of the buried pipe.

[0095] In this embodiment, the setting of the ground source heat pump unit includes the ground source heat pump rated cooling / heating capacity, rated flow, cooling / heating performance coefficient, heating and cooling mode, and rated evaporator and condenser flow.

[0096] S5. Set the ground heat exchanger part.

[0097] In this embodiment, setting the buried pipe heat exchanger part includes setting the vertical buried pipe length and pipe diameter, and U-shaped pipe parameters.

[0098] S6. Set the hot water tank part.

[0099] In this embodiment, the hot water storage tank setting part includes setting the hot water storage tank volume, the outer wall temperature of the hot water storage tank, the heat capacity and density of the medium in the water tank, the heat loss coefficient per unit area of ​​the hot water storage tank, the node height, the auxiliary heating mode, the set heating temperature, and the dead zone temperature difference of the heating water tank. The hot water storage tank volume is determined according to the heating terminal building load, the design hourly heat consumption duration, and the design hot water storage tank supply and return water temperature difference; the outer wall temperature of the hot water storage tank is set to the ambient temperature.

[0100] S7. Set the circulating water pump.

[0101] In this embodiment, setting the circulating water pump includes setting the water pump flow rate, head and efficiency, and start and stop control signals.

[0102] Furthermore, the circulating water flow rate of the PV / T collector system is determined according to the total PV / T area and the unit area flow rate of the working fluid:

[0103] G=A indirect ×m A ;

[0104] Where G is the flow rate of PV / T circulating water pump, kg / h; A indirect = PV / T total area, m 2 ;m A is the flow rate per unit area of ​​the working fluid, kg / (h·m 2 ).

[0105] Furthermore, the circulating water flow rate of the circulating water pump on the terminal building load side is determined according to the larger value of the cold and hot terminal building loads of the design building and the supply and return water temperature difference on the terminal building load side:

[0106]

[0107] Among them, G is the flow rate of the circulating water pump on the load side, kg / h; Q is the maximum value of the building's cooling and heating load, W; Δt is the temperature difference between the supply and return water temperatures on the design load side, ℃; c is the specific heat capacity of water, J / (kg·℃);

[0108] Furthermore, the circulating water flow rate of the circulating water pump on the ground source side is determined according to the larger value of the cold and hot terminal building load of the designed building, the energy efficiency ratio of the ground source heat pump unit and the supply and return water temperature difference on the ground source side:

[0109]

[0110] Among them, G is the flow rate of the circulating water pump on the ground source side, kg / h; Q is the maximum value of the building's cooling and heating load, W; Δt is the designed temperature difference between the supply and return water temperatures on the ground source side, ℃; c is the specific heat capacity of water, J / (kg·℃);

[0111] Furthermore, the water pump power corresponding to the water pump is determined according to the corresponding water pump flow, head and efficiency:

[0112]

[0113] Among them, N is the pump power, W; G is the pump flow, kg / h; H is the pump head, m; η is the pump efficiency.

[0114] S8. Set the water pump operation control part.

[0115] In this embodiment, the PV / T circulating water pump operation control part adopts temperature difference control. The start condition is: when the heating demand is received during the heating period and the difference between the outlet water temperature of the PV / T collector and the outlet temperature of the water tank heat source is greater than 8°C, the differential controller is used to complete: if the controller is currently in the on state, then

[0116]

[0117] If the controller is currently in the off state, then:

[0118]

[0119] Where, γ is the output signal; T h is the input high temperature, which is represented by the outlet water temperature of the PV / T collector in this system; T l The input low temperature is represented by the outlet water temperature of the water tank flowing to PV / T in this system; ΔT h is the upper limit of the dead zone; ΔT l It is the lower limit of the dead zone; 0 means the closing command; 1 means the opening command.

[0120] Conditions for starting the ground source side circulating water pump: receiving hourly hot and cold load demands during the heating / cooling period and the water tank temperature is lower than 58°C during the heating period.

[0121] Conditions for starting the circulating water pump on the load side: receiving hourly hot and cold load demands during the heating / cooling period.

[0122] Conditions for starting the circulating water pump: When the hourly heat load demand is received during the heating period and the water tank temperature is lower than 58°C when PV / T is used for heating alone during the heating period.

[0123] S9, setting heating / cooling time part.

[0124] In this embodiment, the heating / cooling time is determined according to the specific regulations and climate conditions of the simulated area.

[0125] S10. Set the control mode of the valve assembly.

[0126] In this embodiment, the valve switch corresponding to the valve assembly is controlled by the control subsystem; the differential controller is used to control the third diverter valve. The principle is: if the PV / T circulating water pump reaches the starting condition and the ground source heat pump unit is also started, the diverter valve signal is Q pump / Q PV / Tp ; If the PV / T circulating water pump reaches the start-up conditions and the ground source heat pump unit is not started, the diverter valve signal is 0; if the PV / T circulating water pump does not reach the start-up conditions, the flow of the third diverter valve flows entirely to the ground source heat pump unit, and the signal is 1.

[0127] The control equation is expressed as follows:

[0128]

[0129] Among them, γ valve is the output signal of the third diverter valve; T h is the input high temperature, which is expressed as the outlet water temperature of PV / T in this system; T l The input low temperature is represented by the outlet water temperature of the water tank flowing to PV / T in this system; ΔT h is the upper limit of the dead zone; ΔT l It is the lower limit of the dead zone; 0 means the closing command; 1 means the opening command.

[0130] The control logic of the second diverter valve is: if the ground source heat pump unit heating condition is met, the second diverter valve opens in direction ①; if the ground source heat pump unit cooling condition is met, the second diverter valve opens in direction ②. The control equation is expressed as follows:

[0131]

[0132] The control part of the first diverter valve adopts the form of a control calculator, and the control logic is: if the heating condition is met and the load end outlet temperature is higher than 55°C, the first diverter valve opens in direction ③; if the load end outlet temperature is lower than 55°C, the first diverter valve opens in direction ②. If the heating condition is met, the first diverter valve opens in direction ①.

[0133] In a preferred embodiment, it can also include a simulated graphic and data output device. The data output represents the annual outdoor temperature, inclined solar irradiance, PV / T collector heat collection and power generation, annual cumulative heat collection and power generation, heat pump unit, water pump operating power and energy consumption, heat pump unit cooling and heating capacity, cooling and heating performance coefficient, water storage tank load side outlet water temperature, heating power and cumulative heat supply, buried pipe inlet and outlet temperature and other data.

[0134] The specific implementation process of the PV / T coupled ground source heat pump trigeneration system model and modeling method of the present invention is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0135] like Figure 1 As shown, the PV / T coupled ground source heat pump trigeneration system model provided in this embodiment includes a heating subsystem, a cooling subsystem, a power generation subsystem and a control subsystem.

[0136] The heating subsystem is used to switch the heating mode according to the solar radiation intensity and the outlet water temperature of the hot water storage tank. The heating subsystem is implemented by the meteorological parameter module 1, PV / T collector 2, PV / T circulating water pump 3, hot water storage tank 4, mixing valve 5, heating / cooling terminal building load 6, diverter valve 7, ground source heat pump unit 8, ground source side circulating water pump 9, buried pipe heat exchanger 10, diverter valve 11, load side circulating water pump 12, diverter valve 13, circulating water pump 14 and mixing valve 15. Among them, the meteorological parameter module 1 is connected to the PV / T collector 2 to transmit the meteorological parameters to the PV / T collector 2. The PV / T circulating water pump 3 is connected to the PV / T collector 2 and the hot water storage tank 4 for heat transfer. The PV / T circulating water pump 3 transfers the temperature and flow of the heat transfer medium to the PV / T collector 2. The PV / T collector 2 is connected to the lower coil of the hot water storage tank 4 through the mixing valve 18 to transfer heat to the hot water storage tank 4. The load side outlet of the hot water storage tank 4 is connected to the heating / cooling terminal building load 6 through the mixing valve 5. The heating / cooling terminal building load 6 is connected to the cold side inlet of the hot water storage tank 4 through the diverter valve 7. The ground source side outlet of the ground source heat pump unit 8 is connected to the inlet of the ground pipe heat exchanger 10 through the ground source side circulating water pump 9. The outlet of the ground pipe heat exchanger 10 is connected to the ground source side inlet of the ground source heat pump unit 8, completing the ground source side heat flow transfer cycle of the ground source heat pump unit 8. The load-side outlet of the geothermal heat pump unit 8 is connected to the hot water storage tank 4 through the diverter valve 11, and the hot water storage tank 4 is connected to the inlet side of the hot water storage tank 4 through the mixing valve 5, the load-side circulating water pump 12, the heating / cooling terminal building load 6, and the diverter valve 7. The heat source outlet of the hot water storage tank 4 is connected to the load-side inlet of the geothermal heat pump unit 8 through the diverter valve 13, the circulating water pump 14, and the mixing valve 15, completing the heat flow transfer cycle on the load side of the geothermal heat pump unit 8. Among them, the graphic and data output device 16 is respectively connected to the meteorological parameter module 1, the PV / T collector 2, the ground source heat pump unit 8, the ground source side circulating water pump 9, the load side circulating water pump 12, the circulating water pump 14 and the hot water storage tank 4, and is used to output the annual outdoor temperature, the inclined surface solar irradiance, the PV / T collection rate, the annual cumulative collection heat, the heat pump unit, the water pump operating power and energy consumption, the heat pump unit heating capacity, the heating performance coefficient, the load side water outlet temperature of the hot water storage tank, the heating power and the cumulative heat supply, the inlet and outlet temperature of the buried pipe and other data.

[0137] The refrigeration subsystem is implemented by the heating / cooling terminal building load 6, the ground source heat pump unit 8, the water pump assembly, the valve assembly and the heating / cooling season time controller 17; wherein, the ground source side outlet of the ground source heat pump unit 8 is connected to the inlet of the ground pipe heat exchanger 10 through the ground source side circulating water pump 9, and the outlet of the ground pipe heat exchanger 10 is connected to the ground source side inlet of the ground source heat pump unit 8. The load side outlet of the ground source heat pump unit 8 is connected to the mixing valve 5, the load side circulating water pump 12, the heating / cooling terminal building load 6, the diverter valve 7 and the mixing valve 15 to the load side inlet of the ground source heat pump unit 8 through the diverter valve 11. wherein, the graphic and data output device 16 is connected to the ground source heat pump unit 8, the ground source side circulating water pump 9 and the ground pipe heat exchanger 10, and outputs the heat pump unit, the water pump operating power and energy consumption, the heat pump unit cooling capacity, the cooling performance coefficient, the ground pipe inlet and outlet temperature, etc.

[0138] The power generation subsystem is implemented by the meteorological parameter module 1, the PV / T collector 2 and the inverter 21; wherein the meteorological parameter module 1 is connected to the PV / T collector 2, and the PV / T collector 2 is connected to the inverter 21 for outputting electric energy. The graphic and data output device 16 is connected to the PV / T collector 2 to output the PV / T power generation, the annual cumulative power generation, etc.

[0139] The control subsystem is used to control the start and stop of valve components and water pump components and flow through various controllers to achieve the switching between cooling and three heating modes. The specific implementation process is as follows:

[0140] Control of PV / T circulating water pump 3: The self-feedback temperature difference controller 19 is connected to the heating / cooling terminal building load 6, the lower coil of the hot water storage tank 4, the PV / T collector 2 and the PV / T circulating water pump 3, and transmits the heat source outlet temperature of the hot water storage tank 4 and the water outlet temperature of the PV / T collector to the self-feedback temperature difference controller 19, and the self-feedback temperature difference controller 19 transmits the control signal to the PV / T circulating water pump 3 for control operation.

[0141] Water tank temperature control: The water tank temperature controller is connected to the hot water storage tank 4 to monitor the load-side outlet water temperature of the hot water storage tank 4. The outlet water temperature is combined with the heating / cooling time and the heating / cooling terminal building load to generate control instructions after calculation. The control instructions are used to control the start and stop of the ground source side circulating water pump 9, the load side circulating water pump 12 and the circulating water pump 14 to switch between three different heating modes.

[0142] Control of the diverter valve 13: The controller of the diverter valve 13 is connected to the water tank temperature controller, the heating / cooling season time controller 17, and the heating / cooling terminal building load 6. After calculation and considering that the PV / T circulating water pump 3 meets the starting conditions and the ground source heat pump unit 8 also meets the starting conditions, the diverter valve 13 generates a control instruction according to the principle determined by the ratio of the circulating water pump flow rate to the PV / T circulating water pump flow rate.

[0143] Control of the diverter valve 11: The controller of the diverter valve 11 is connected to the heating / cooling season time controller 17, and generates a control signal according to the heating / cooling season time controller 17.

[0144] Control of diverter valve 7: The controller of diverter valve 7 is connected to the load-side circulating water pump 12, mixing valve 5, hot water storage tank 4, heating / cold season time controller 17 and heating / cooling terminal building load 6, and generates control conditions based on whether the heating conditions are met and whether the terminal load outlet temperature is higher than 55°C.

[0145] For ease of understanding, the functions of each device and module are described below: Meteorological parameter module 1 is used to set meteorological parameters. PV / T collector 2 is used to set the benchmark power generation efficiency, the temperature corresponding to the benchmark power generation efficiency, the emissivity of the photovoltaic panel, and the factor affecting the power generation efficiency by temperature. Hot water storage tank 4 is used to set the volume of the hot water storage tank, the heat loss coefficient of the hot water storage tank, and the auxiliary heating mode. The temperature controller includes a water tank temperature controller and a self-feedback temperature difference controller 19, wherein the water tank temperature controller is used to set the start and stop of the ground source heat pump unit according to the water tank temperature, and the self-feedback temperature difference controller 19 is used to output an open or close command according to the temperature difference between the water temperature at the outlet of the hot water tank and the water temperature at the bottom of the pool; the buried pipe heat exchanger 10 is used to set the length and diameter of the vertical buried pipe and the U-shaped pipe parameters of the buried pipe; the ground source heat pump unit 8 is used to set the rated cooling heating capacity, rated flow, nominal cooling and heating performance coefficient and rated evaporator and condenser flow of the ground source heat pump in the heating and cooling mode; the heating / cooling terminal building load 6 is used to set the system heating heat load and cooling load; the water pump assembly and valve assembly are used to set the water pump flow, power and valve switch; the heating / cold season time controller 17 is used to set the heating / cooling time; the circulating water pump start control calculator 20 is used to set the start and stop of the water pump and valve; the graphic and data output device 16 is used to set the output parameters and output graphics and data, etc.

[0146] like Figure 1 The system is built according to the PV / T coupled ground source heat pump cooling, heating and power trigeneration system model of a gymnasium. The gymnasium construction site is the original basketball court in the park, with a total of 2 floors. It is a multi-storey public building with a total construction area of ​​4128.53m 2 ,The implementation process of the specific modeling method is;

[0147] S1. Set the heating / cooling terminal building load to 6.

[0148] In this embodiment, the heating / cooling terminal building load 6 is calculated according to the building cold and hot terminal building load calculation software; the building cold and hot terminal building load calculation software sets the building attributes (such as population density, enclosure structure parameters, etc.) and usage conditions, and considers the influence of various factors (such as outdoor temperature changes, solar radiation, etc.), and uses the harmonic response method to calculate the heating terminal building load: the maximum cooling load of the building design is 451.75kw, and the air-conditioned area is 2968.17m 2 The building cooling index is 152.20W / m 2 The maximum heat load of the building design is 363.29kw. The cumulative heat consumption in the heating season is 299,100 KWh (low power operation at night). The heating area is 3124.34m 2 The building heat index is 116.28W / m 2 .

[0149] S2. Set the meteorological parameter input part.

[0150] In this embodiment, the meteorological parameter file of Gaobeidian City is generated by Meteonorm software, including outdoor temperature, humidity, wind speed and solar radiation intensity. The solar radiation intensity and ambient temperature are determined by the meteorological parameter input part.

[0151] S3. Set relevant parameters of PV / T collector 2.

[0152] In this embodiment, the PV / T collector area is determined according to the total area of ​​the direct system collector, the total heat loss coefficient of the collector and the heat transfer coefficient of the heat exchanger, and the expression is:

[0153]

[0154] Among them, A indirect =PV / T total area, calculated to be 831m 2 ; A c is the total area of ​​direct system PV / T, m 2 ; U L is the total heat loss coefficient of the collector, taking 4W / (m 2 ℃); U hx The heat transfer coefficient of the heat exchanger is 1100W / (m 2 ℃); A hx Heat exchange area of ​​indirect system heat exchanger, m 2 .

[0155] Among them, direct system PV / T total area A cIt is determined based on the total heating terminal building load, solar energy guarantee rate, annual average daily solar radiation on the local PV / T collector lighting surface, average heat collection efficiency of PV / T collector and heat loss rate of pipeline and heat storage device. The expression is as follows:

[0156]

[0157] Among them, A c is the total area of ​​direct system PV / T, m 2 , Q J Design heat load for the solar collector system, kW; J T is the annual average daily solar radiation intensity on the local collector lighting surface (the annual integral of the radiation intensity is calculated and then divided by 365), which is 2376 kJ / (m 2 ·d); f is the solar energy guarantee rate, which is 17.26%; η cd is the average collector efficiency based on the total area, determined according to the product parameters provided by the manufacturer, and is taken as 48%; η L is the heat loss rate of pipelines and heat storage devices, which is taken as 15%.

[0158] S4. Setting relevant parameters of the ground source heat pump unit 8.

[0159] In this embodiment, the rated cooling and heating capacity, nominal cooling and heating performance coefficient, rated flow rate and rated evaporator and condenser flow rate, rated chilled water outlet temperature for cooling, rated cooling water return temperature, rated water supply temperature for heating, and rated evaporator inlet temperature of the ground source heat pump unit are all determined based on the cooling and heating loads of the building and the product parameters provided by the manufacturer.

[0160] S5. Setting relevant parameters of the ground pipe heat exchanger 10.

[0161] In this embodiment, the selection of the U-tube diameter should be determined according to the flow requirements of the heat exchanger of the ground source heat pump itself and the selected series or parallel form. The length of the U-tube is determined according to the local geological conditions, the available land area and the ground temperature parameters obtained from the geothermal response test. The specific calculation formula is as follows:

[0162] L c =1000Q re / q f ;

[0163] L n =1000nQ ab / q x ;

[0164] Among them, L c is the required length of underground pipe under summer working conditions, m; L n is the required length of underground pipe under winter working conditions; q fThe heat released per unit depth of the borehole is 49.93W / m according to the geotechnical thermal response test under summer working conditions of 35 / 30℃; q x The heat absorbed by the unit depth of the borehole is 33.79W / m according to the geotechnical thermal response test under winter working conditions of 10 / 5℃;

[0165] In summer cooling:

[0166] Q re =Q co ×(1+1 / ERR);

[0167] In winter heating:

[0168] Q ab =Q hot ×(1-1 / COP);

[0169] Where: Q re is the maximum heat release of the heat pump in summer, kW; Q co For the summer design cooling load, take 451.75kW; Q ab is the heat absorbed from the soil in winter, kW; Q hot is the total design heat load in winter, which is 363.29kW; ERR is the refrigeration performance coefficient of the heat pump unit under the design conditions, which is 5.80; COP is the heating performance coefficient of the heat pump unit under the design conditions, which is 4.81.

[0170] The number of holes drilled is determined by the following formula:

[0171]

[0172] Where N is the number of holes drilled, L is the total length of the buried pipe, take L n , L c The larger of the two, m; l-borehole depth, usually in the range of 40-200m. According to the available buried pipe area on site, 100m is selected for this project. According to the calculation results, a certain margin is reserved and the number of boreholes is 120.

[0173] S6. Setting relevant parameters of the hot water storage tank 4.

[0174] In this embodiment, the volume of the hot water storage tank is determined according to the heating terminal building load, the design hourly heat consumption duration, and the design supply and return water temperature difference of the hot water storage tank; the outer wall temperature of the hot water storage tank is set to the ambient temperature;

[0175]

[0176] Where V is the volume of the hot water storage tank, m 3; T is the design hourly heat consumption duration, which is 2h; Q is the water tank heating load, which is 363.29kw; △t is the design water storage tank supply and return water temperature difference, which is 8℃; ρ r is the density of hot water, 1000kg / m 3 ; C is the specific heat of water, 4.178 kJ / (kg·K).

[0177] S7. Set relevant parameters of all circulating water pumps.

[0178] In this embodiment, the circulating water flow rate of the PV / T collector 2 is determined according to the total area of ​​the PV / T and the unit area flow rate of the working fluid:

[0179] G=A indirect ×m A ;

[0180] Where G is the flow rate of PV / T circulating water pump, kg / h; A indirect = PV / T total area, m 2 ;m A is the unit area flow rate of the working fluid, taking 0.09kg / (h·m 2 ).

[0181] The circulating water flow rate of the circulating water pump 12 on the load side of the terminal building is determined according to the larger value of the terminal building load 6 for heating / cooling of the design building and the supply and return water temperature difference on the load side of the terminal building:

[0182]

[0183] Among them, G is the flow rate of the circulating water pump on the load side, kg / h; Q is the maximum value of the building's cooling and heating load, W; Δt is the temperature difference between the supply and return water temperatures on the design load side, which is 5°C; c is the specific heat capacity of water, which is 4180J / (kg·℃);

[0184] The circulating water flow rate of the circulating water pump 9 on the ground source side is determined according to the larger value of the cold and hot terminal building load of the designed building, the energy efficiency ratio of the ground source heat pump unit and the temperature difference between the supply and return water on the ground source side:

[0185]

[0186] Among them, G is the flow rate of the circulating water pump on the ground source side, kg / h; Q is the maximum value of the building's cooling and heating load, W; Δt is the designed temperature difference between the supply and return water on the ground source side, which is 5°C; c is the specific heat capacity of water, which is 4180J / (kg·℃);

[0187] The water pump power corresponding to the water pump is determined according to the corresponding water pump flow, head and efficiency:

[0188]

[0189] Wherein, N is the pump power, W; G is the pump flow, kg / h; H is the pump head, m; η is the pump efficiency, %.

[0190] S8. Set the water pump operation control part.

[0191] In this embodiment, the operation control part of the PV / T circulating water pump 3 adopts temperature difference control. The start condition is: when the heating demand is received during the heating period and the difference between the outlet water temperature of the PV / T collector 2 and the outlet temperature of the water tank heat source is greater than 8°C, the differential controller is used to complete:

[0192] If the controller is currently on, then:

[0193]

[0194] If the controller is currently in the off state, then:

[0195]

[0196] Among them, γ is the output signal, T h is the input high temperature, which is represented by the outlet water temperature of the PV / T collector in this system, T l The input low temperature is represented by the outlet water temperature of the water tank flowing to PV / T in this system, ΔT h For the upper limit of the dead zone, take 8℃, ΔT l The lower limit of the dead zone is 2°C. 0 represents a close command and 1 represents an open command.

[0197] The conditions for starting the ground source side circulating water pump 9 are: the heating and cooling load demand during the heating / cooling period reaches more than 10% of the rated load and the water tank temperature is lower than 58°C during the heating period.

[0198] The start-up condition of the load-side circulating water pump 12 is: receiving hourly hot and cold load demands during the heating / cooling period.

[0199] The conditions for starting the circulating water pump 14 are: the heating and cooling load demand reaches more than 10% of the rated load during the heating / cooling period and the water tank temperature is lower than 58°C when PV / T is used for heating alone during the heating period.

[0200] S9, setting heating / cooling season time part.

[0201] In this embodiment, the heating season is set from November 15 to March 15 of the following year; the cooling season is from June 15 to September 15. The air conditioning operation hours of the gymnasium are: working days (Monday to Friday): 14:00-21:00, the air conditioning is turned on, and the rest of the time is turned off; non-working days (weekends, holidays), 9:00-21:00, the air conditioning is turned on, and the rest of the time is turned off. The heat pump unit does not run at night in the transition season and the cooling season, and the heat pump unit runs at low power at night in the heating season. When the building load is less than 10% of the unit's design load, the system stops running.

[0202] S10, setting the control module of the valve assembly.

[0203] In this embodiment, the control logic of the diverter valve 13 is as follows: if the PV / T circulating water pump 3 reaches the start-up condition, and the ground source heat pump unit 8 also reaches the start-up condition, the diverter valve 13 is determined according to the ratio of the circulating water pump flow rate to the upper PV / T circulating water pump flow rate, and the signal is 0.56; if the PV / T circulating water pump 8 reaches the start-up condition, and the ground source heat pump unit 8 does not reach the start-up condition, then the diverter valve signal is 0; if the PV / T circulating water pump 3 does not reach the start-up condition, the flow of the diverter valve 13 flows entirely to the ground source heat pump unit 8, and the signal is 1. The control equation is expressed in the following form:

[0204]

[0205] Among them, γ valve is the output signal of the diverter valve 13, m pump is the circulating water pump flow rate, m pump is PV / T circulating water pump flow, T h The high temperature is input, which is represented by the outlet water temperature of PV / T in this system, T l The input low temperature is represented by the outlet water temperature of the water tank flowing to PV / T in this system, ΔT h For the upper limit of the dead zone, take 8℃, ΔT l The lower limit of the dead zone is 2°C. 0 represents a close command and 1 represents an open command.

[0206] The control logic of the diverter valve 11 is: if the heating condition of the ground source heat pump unit 8 is met, that is, in the heating season and the heating load reaches more than 10% of the rated load of the unit, the diverter valve 11 opens in direction ①; if the cooling condition of the ground source heat pump unit 8 is met, that is, in the cooling season and the cooling load reaches more than 10% of the rated load of the unit, the diverter valve 11 opens in direction ②. The control equation is expressed as follows:

[0207]

[0208] The control part of the diverter valve 7 adopts the form of a control calculator, and the control logic is: if the heating condition is met and the terminal load outlet temperature is higher than 55°C, the diverter valve 7 opens in direction ③, and if the terminal load outlet temperature is lower than 55°C, the diverter valve 7 opens in direction ②; if the cooling condition is met, the diverter valve 7 opens in direction ①.

[0209] S11, setting the graphics and data output device 16.

[0210] In this embodiment, the data output characterizes the annual outdoor temperature, inclined surface solar irradiance, PV / T collector collection and power generation power, annual cumulative collection and power generation, heat pump unit, water pump operating power and energy consumption, heat pump unit cooling and heating capacity, cooling and heating performance coefficient, load-side outlet water temperature of the hot water storage tank, heating power and cumulative heat supply, buried pipe inlet and outlet temperatures, etc.

[0211] The simulation results of the PV / T coupled ground source heat pump trigeneration system model in this embodiment are as follows: Figure 2-6 As shown. Among them, Figure 2 Indicates the local outdoor temperature throughout the year and the solar radiation intensity on the inclined surface; Figure 3 Indicates the real-time heat collection and power generation of PV / T modules and the cumulative heat collection and power generation throughout the year; Figure 4 Indicates the annual operating power of the heat pump unit and water pump; Figure 5 Indicates the annual heating / cooling power and energy consumption of the ground source heat pump and the hot water storage tank; Figure 6 It indicates the annual underground pipe inlet and outlet temperature and the average soil temperature of the ground source heat pump. Figure 2-6 It can be seen that the simulation results of the PV / T coupled ground source heat pump trigeneration system model of the present invention are in good agreement with the design parameters and theoretical analysis data, indicating the accuracy and reliability of the model.

[0212] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In the description of this specification, the description of reference terms "a preferred embodiment", "further", "specifically", "in the present embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradiction.

[0213] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PV / T coupled ground source heat pump trigeneration system model, characterized in that: The system includes a meteorological parameter module, a PV / T collector, a PV / T circulating water pump, a heating / cooling terminal building load, a ground source heat pump unit, a buried pipe heat exchanger, a water pump assembly, a valve assembly, a heating / cold season time controller, a hot water storage tank, an inverter and a controller. The heating subsystem, the cooling subsystem, the power generation subsystem and the control subsystem are constructed respectively through the combination of the above devices, and the switching of the cooling and heating modes is realized by controlling the start and stop and the flow of the valve assembly and the water pump assembly.

2. The PV / T coupled ground source heat pump trigeneration system model according to claim 1 is characterized in that: The heating subsystem is implemented by a meteorological parameter module, a PV / T collector, a PV / T circulating water pump, a heating / cooling terminal building load, a ground source heat pump unit, a buried pipe heat exchanger, a water pump assembly, a valve assembly, a heating / cold season time controller and a hot water storage tank, wherein the meteorological parameter module is connected to the PV / T collector, the PV / T circulating water pump is connected to the PV / T collector and the hot water storage tank, the load side outlet of the hot water storage tank is connected to the heating / cooling terminal building load through a first mixing valve, and the heating / cooling terminal building load is connected to the heat storage tank through a first diverter valve. The cold side inlet of the water tank; the ground source side outlet of the ground source heat pump unit is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, and the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit; the load side outlet of the ground source heat pump unit is connected to the hot water storage tank through the second diverter valve, and the hot water storage tank is connected to the inlet side of the hot water storage tank through the first mixing water valve, the load side circulating water pump, the heating / cooling terminal building load, and the first diverter valve; the heat source outlet of the hot water storage tank is connected to the load side inlet of the ground source heat pump unit through the third diverter valve, the circulating water pump, and the second mixing water valve.

3. The PV / T coupled ground source heat pump trigeneration system model according to claim 2 is characterized in that: The refrigeration subsystem is implemented by the heating / cooling terminal building load, the ground source heat pump unit, the water pump assembly, the valve assembly and the heating / cooling season time controller, wherein the ground source side outlet of the ground source heat pump unit is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit, the load side outlet of the ground source heat pump unit is connected to the first mixing valve through the second diverter valve, the first mixing valve is connected to the load side inlet of the ground source heat pump unit through the load side circulating water pump, the heating / cooling terminal building load, the first diverter valve and the second mixing valve.

4. The PV / T coupled ground source heat pump trigeneration system model according to claim 3 is characterized in that: The power generation subsystem is implemented by a meteorological parameter module, a PV / T collector and an inverter. The meteorological parameter module is connected to the PV / T collector, and the PV / T collector is connected to the inverter for outputting electric energy.

5. The PV / T coupled ground source heat pump trigeneration system model according to claim 4 is characterized in that: The control subsystem controls the start and stop of the valve assembly and the water pump assembly and the flow rate through different controllers to achieve the switching between the cooling and heating modes. The specific process includes one or more of the following controls: Control PV / T circulating water pump: The self-feedback temperature difference controller is connected to the heating / cooling terminal building load, the hot water storage tank, the PV / T collector and the PV / T circulating water pump, and transmits the measured outlet temperature of the hot water storage tank heat source and the outlet water temperature of the PV / T collector to the self-feedback temperature difference controller. The self-feedback temperature difference controller transmits the control signal to the PV / T circulating water pump for control based on the obtained temperature value; Control the temperature of the hot water storage tank: The water tank temperature controller is connected to the hot water storage tank to monitor the outlet water temperature on the load side of the hot water storage tank. The outlet water temperature is combined with the heating / cooling time and the heating / cooling terminal building load to generate control instructions through calculation. The control instructions are used to control the circulating water pump on the ground source side, the circulating water pump on the load side, and the start and stop of the circulating water pump to achieve switching between different heating modes; Control the third diverter valve: The third diverter valve controller is connected to the water tank temperature controller, the heating / cooling season time controller and the heating / cooling terminal building load. After calculation and considering that if the PV / T circulating water pump meets the start-up conditions and the ground source heat pump unit also meets the start-up conditions, the third diverter valve generates a control instruction for control according to the principle determined by the ratio of the circulating water pump flow rate to the PV / T circulating water pump flow rate; Controlling the second diverter valve: the second diverter valve controller is connected to the heating / cooling season time controller, and generates a control signal according to the heating / cooling season time controller; Control the first diverter valve: The first diverter valve controller is connected to the load-side circulating water pump, the first mixing valve, the hot water storage tank, the heating / cold season time controller and the heating / cooling terminal building load, and generates control conditions based on whether the heating conditions are met and whether the terminal load outlet temperature is higher than the preset temperature.

6. The PV / T coupled ground source heat pump trigeneration system model according to claim 5 is characterized in that: The heating operation modes of the heating subsystem include PV / T independent heating mode, mixed heating mode and ground source heat pump independent heating mode, wherein: In the PV / T independent heating mode, the operation process of the heating subsystem is as follows: the hot side outlet of the water storage tank is connected to the third diverter valve, the outlet of the third diverter valve is connected to the inlet of the PV / T collector through the PV / T circulating water pump, and the outlet of the PV / T collector is connected to the hot side inlet of the water storage tank through the first mixing valve; the cold side outlet of the water storage tank is connected to the load side circulating water pump, the outlet of the load side circulating water pump is connected to the terminal building load through the first mixing valve, and the terminal building load is connected to the cold side inlet of the water storage tank through the first diverter valve; In the hybrid heating mode, the operation process of the heating subsystem is as follows: the hot side outlet of the hot water storage tank is connected to the third diverter valve, and the outlet ① of the third diverter valve is connected to the inlet of the PV / T collector through the PV / T circulating water pump, and the outlet of the PV / T collector is connected to the hot side inlet of the hot water storage tank through the first mixing valve; the hot side outlet of the hot water storage tank is connected to the third diverter valve, and the outlet ① of the third diverter valve is connected to the load side inlet of the ground source heat pump through the circulating water pump and the second mixing valve, and the load side outlet of the ground source heat pump is connected to the hot side inlet of the hot water storage tank through the second diverter valve and the third mixing valve; the ground source side outlet of the ground source heat pump is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, and the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump; the cold side outlet of the hot water storage tank is connected to the load side circulating water pump, and the outlet of the load side circulating water pump is connected to the terminal building load through the first mixing valve, and the terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve; In the ground source heat pump separate heating mode, the operation process of the heating subsystem is as follows: the ground source side outlet of the ground source heat pump unit is connected to the inlet of the buried pipe heat exchanger through the ground source side circulating water pump, and the outlet of the buried pipe heat exchanger is connected to the ground source side inlet of the ground source heat pump unit; the cold side outlet of the hot water storage tank is connected to the load side circulating water pump, and the outlet of the load side circulating water pump is connected to the heating\cooling terminal building load through the first mixing valve, and the heating\cooling terminal building load is connected to the cold side inlet of the hot water storage tank through the first diverter valve.

7. A modeling method based on the PV / T coupled ground source heat pump trigeneration system model according to any one of claims 2 to 6, characterized in that: include: Setting heating / cooling terminal building load: The building cooling and heating terminal building load calculation software sets the building's attributes and usage, and considers the influencing factors using the harmonic response method; Set meteorological parameter inputs, including outdoor temperature, humidity, wind speed, and solar radiation intensity; Set the relevant parameters of the PV / T collector, including the PV / T collector area, the PV / T module tilt angle, the PV / T module heat collection efficiency factor, the medium fluid heat capacity, the PV / T collector plate emissivity, the reference temperature of the photovoltaic part power generation efficiency, the photovoltaic power generation efficiency in the PV / T module at the reference temperature, the photovoltaic power generation efficiency correction temperature coefficient, the packaging coefficient, the PV / T module bottom and edge heat loss coefficient and the number of glass covers; Set the parameters of the ground source heat pump unit, including the ground source heat pump rated cooling / heating capacity, rated flow, cooling / heating performance coefficient, heating and cooling mode, rated evaporator and condenser flow; Set the parameters of the underground heat exchanger, including the vertical buried pipe length and diameter, and U-shaped pipe parameters; Set the parameters of the hot water storage tank, including the volume of the hot water storage tank, the outer wall temperature of the hot water storage tank, the heat capacity and density of the medium in the water tank, the heat loss coefficient per unit area of ​​the hot water storage tank, the node height, the auxiliary heating mode, the set heating temperature and the dead zone temperature difference of the heating water tank; Set water pump parameters, including water pump flow, head and efficiency, and start and stop control signals; Set the control mode of water pump operation; Setting the heating / cooling time, wherein the heating / cooling time is determined according to the regulations and climate conditions of the simulated area; Set the control mode of the valve assembly.

8. The modeling method of the PV / T coupled ground source heat pump trigeneration system model according to claim 7 is characterized in that: Set the pump parameters, including the pump flow, head, efficiency and start / stop control signals. The specific process is as follows: The circulating water flow rate of the PV / T circulating water pump is determined according to the total area of ​​PV / T and the unit area flow rate of the working fluid: G=A indirect ×m A ; Where G is the flow rate of PV / T circulating water pump; A indirect =PV / T total area; m A is the flow rate per unit area of ​​the working fluid; The circulating water flow rate of the circulating water pump on the load side is determined according to the larger value of the cold and hot terminal building loads of the designed building and the supply and return water temperature difference on the load side of the terminal building: Among them, G is the flow rate of the circulating water pump on the load side; Q is the maximum value of the building's cooling and heating load; Δt is the temperature difference between the supply and return water temperatures on the design load side; c is the specific heat capacity of water; The circulating water flow rate of the circulating water pump on the ground source side is determined according to the larger value of the cold and hot terminal building load of the designed building, the energy efficiency ratio of the ground source heat pump unit and the temperature difference between the supply and return water on the ground source side: Among them, G is the flow rate of the circulating water pump on the ground source side; Q is the maximum value of the building's cooling and heating load; Δt is the designed temperature difference between the supply and return water temperatures on the ground source side; c is the specific heat capacity of water; The pump power corresponding to the circulating water pump is determined according to the corresponding pump flow, head and efficiency: Among them, N is the pump power; G is the pump flow; H is the pump head; η is the pump efficiency.

9. The modeling method of the PV / T coupled ground source heat pump trigeneration system model according to claim 7 is characterized in that: Set the water pump operation control mode. The specific implementation process is as follows: The PV / T circulating water pump operation control part adopts temperature difference control. The start condition is: when the heating demand is received during the heating period and the difference between the outlet water temperature of the PV / T collector and the outlet temperature of the heat source of the hot water storage tank is greater than 8°C, it is completed by using a differential controller: if the controller is currently in the on state, then: If the controller is currently in the off state, then: Where, γ is the output signal; T h is the input high temperature, which is represented by the outlet water temperature of the PV / T collector in this system; T l The input low temperature is represented by the outlet water temperature of the water tank flowing to PV / T in this system; ΔT h is the upper limit of the dead zone; ΔT l The lower limit of the dead zone; 0 means the closing command; 1 means the opening command; Conditions for starting the ground source side circulating water pump: receiving hourly heating and cooling load demands during the heating / cooling period and the water tank temperature is lower than 58°C during the heating period; Load-side circulating water pump start-up conditions: receiving hourly heating and cooling load demands during the heating / cooling period; Conditions for starting the circulating water pump: When the hourly heat load demand is received during the heating period and the water tank temperature is lower than 58°C when PV / T is used for heating alone during the heating period.

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