PV / T heat pump energy supply system applied to electric engineering machinery and working method of PV / T heat pump energy supply system
By integrating PV/T components and a heat pump into a multi-loop system, the problem of autonomous power supply and thermal management for electric construction machinery in extreme environments has been solved, achieving efficient energy utilization and rapid response.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XCMG CONSTRUCTION MACHINERY CO LTD SCIENCE & TECHNOLOGY BRANCH
- Filing Date
- 2026-03-23
- Publication Date
- 2026-05-19
AI Technical Summary
Electric construction machinery lacks the ability to independently supply power in open-air areas far from mains power, has low energy utilization efficiency, and struggles to meet the thermal management requirements of the three-electric system and the cab in extreme environments.
It integrates PV/T components, heat pumps, and heat exchange devices for the three-electric system to form multiple circulation loops. The flow of the medium is controlled by a three-way valve and a water pump to achieve efficient utilization of thermal and electrical energy, and to meet the heat exchange needs of the cab and the three-electric system.
It improves the energy utilization efficiency of electric construction machinery, extends its range, solves the problem of low-temperature start-up, provides cab heating and heat dissipation/cooling for the three-electric system, and adapts to the needs of extreme environments.
Smart Images
Figure CN122058710A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a functional system and operating method of a photovoltaic-thermal combined heat pump, and particularly to a PV / T heat pump energy supply system and its operating method applied to electric engineering machinery. Background Technology
[0002] Electric construction machinery often operates in open-air environments far from mains power, placing high demands on its self-powering capabilities and adaptability to extreme environments. Currently, the main shortcomings of electric construction machinery are: complete reliance on external power grid supplementation or battery swapping, resulting in high charging and swapping costs and short operating windows in open-air mines, plateaus, and pastoral areas far from or lacking mains power; the need for additional PTC preheating during winter startup, leading to reduced range; and the inability to recover and utilize waste heat from batteries, motors, and electronic controls, resulting in energy waste.
[0003] Existing technologies include solutions that integrate PV / T modules into new energy vehicles. These solutions primarily combine electrical and thermal energy storage devices to provide vehicles with additional power and heat sources. While these solutions can improve the equipment's self-sufficiency in power supply and enhance its environmental adaptability, the integration of PV / T modules with the existing energy management systems of electric construction machinery is low, resulting in low energy utilization efficiency. Summary of the Invention
[0004] To address the shortcomings of the existing technology, this invention provides a PV / T heat pump energy supply system for electric construction machinery, achieving integration with the existing energy management system of the machinery and improving energy utilization efficiency. This invention also provides a method for operating the PV / T heat pump energy supply system for electric construction machinery, further realizing the effective utilization of photovoltaic and solar thermal energy in the machinery.
[0005] The technical solution of this invention is as follows: A PV / T heat pump power supply system applied to electric engineering machinery includes a PV / T module, a heat storage tank, a heat pump, and a heat exchange device for a three-electric system. The heat exchange channel of the heat collection plate of the PV / T module and the first medium channel of the heat storage tank form a first circulation loop. The second medium channel of the heat storage tank forms a second circulation loop. The heat exchange device for the three-electric system forms a third circulation loop. Both the second and third circulation loops extend to the heat pump. The second and third circulation loops can be switched to form a heat exchange structure with the first or second heat exchanger of the heat pump. The cab of the electric engineering machinery forms a heat exchange structure with the first heat exchanger. The second heat exchanger forms a heat exchange structure on the outside air side. The outlet of the second medium channel is connected to the inlet of the heat exchange device for the three-electric system through an openable and closable first bypass. The outlet of the heat exchange device for the three-electric system is connected to the inlet of the second medium channel through an openable and closable second bypass. The heat exchange directions of the first and second heat exchangers are opposite and change simultaneously when the heat pump changes its operating mode.
[0006] Furthermore, to facilitate the control of the medium flow direction, a first three-way valve is installed on the pipeline from the outlet of the second medium channel to the heat pump in the second circulation loop, and a second three-way valve is installed on the pipeline from the inlet of the second medium channel to the heat pump; in the third circulation loop, a third three-way valve is installed on the pipeline from the inlet of the heat exchange device of the three-electric system to the heat pump, and a fourth three-way valve is installed on the pipeline from the outlet of the heat exchange device of the three-electric system to the heat pump, with the bypass outlet of the first three-way valve connected to the bypass inlet of the third three-way valve, and the bypass inlet of the second three-way valve connected to the bypass outlet of the fourth three-way valve.
[0007] Furthermore, a first heat exchange pipeline is provided on the first heat exchanger, and a second heat exchange pipeline is provided on the second heat exchanger. The inlet ends of the first heat exchange pipeline and the second heat exchange pipeline are respectively connected to the first outlet and the second outlet of the fifth three-way valve, and the outlet ends of the first heat exchange pipeline and the second heat exchange pipeline are respectively connected to the first inlet and the second inlet of the sixth three-way valve. The inlet of the fifth three-way valve and the outlet of the sixth three-way valve respectively constitute the second circulation loop extending to the connection port of the heat pump.
[0008] Furthermore, a third heat exchange pipeline is provided on the first heat exchanger, and a fourth heat exchange pipeline is provided on the second heat exchanger. The inlet ends of the third and fourth heat exchange pipelines are respectively connected to the first and second outlets of the seventh three-way valve, and the outlet ends of the third and fourth heat exchange pipelines are respectively connected to the first and second inlets of the eighth three-way valve. The inlet of the seventh three-way valve and the outlet of the eighth three-way valve respectively constitute the third circulation loop extending to the connection port of the heat pump.
[0009] Furthermore, the system includes an integrated inverter unit, through which the photovoltaic cells of the PV / T module supply power to the electrical equipment of the system and charge the power battery of the three-electric system.
[0010] Furthermore, the photovoltaic cells of the PV / T module are any one or more combinations of monocrystalline silicon cells, polycrystalline silicon cells, and perovskite cells.
[0011] Furthermore, the working fluid in the heat exchange channel of the collector plate of the PV / T module is water.
[0012] Furthermore, the electric construction machinery is an electric loader.
[0013] A method for operating a PV / T heat pump energy supply system applied to electric construction machinery includes: When the three-electric system needs preheating, it operates in either a first mode or a second mode. In the first mode, the heat pump is not working, and the working fluid in the second medium channel enters the heat exchange device of the three-electric system through the first bypass to release heat, and then flows back to the second medium channel through the second bypass. In the second mode, the first bypass and the second bypass are closed, the second circulation loop forms a heat exchange structure with the second heat exchanger, the third circulation loop forms a heat exchange structure with the first heat exchanger, the heat pump works and absorbs heat from the second circulation loop and the outside air on the evaporation side of the second heat exchanger, and releases heat to the third circulation loop on the condensation side of the first heat exchanger. When the three-electric system needs heat dissipation and the cab needs heating, the first bypass and the second bypass are closed, the second circulation loop forms a heat exchange structure with the second heat exchanger, the third circulation loop forms a heat exchange structure with the second heat exchanger, the heat pump works and absorbs heat from the second circulation loop, the third circulation loop and the outside air with the second heat exchanger as the evaporation side, and releases heat to the cab with the first heat exchanger as the condensation side. When the three-electric system needs heat dissipation and the cab needs cooling, the first bypass and the second bypass are closed, the second circulation loop forms a heat exchange structure with the first heat exchanger, the third circulation loop forms a heat exchange structure with the first heat exchanger, the heat pump works and absorbs heat from the second circulation loop, the third circulation loop and the cab as the evaporation side of the first heat exchanger, and releases heat to the outside air as the condensation side of the second heat exchanger.
[0014] Furthermore, when the three-electric system needs to be preheated, a first temperature threshold and a second temperature threshold are set. When the working fluid temperature of the second medium channel exceeds the first temperature threshold, it operates in the first mode. When the working fluid temperature of the second medium channel is lower than the second temperature threshold, it switches to the second mode. When it does not operate in the first mode and the working fluid temperature of the second medium channel is lower than the first temperature threshold, it operates in the second mode.
[0015] Compared with the prior art, the advantages of the technical solution provided by the present invention are as follows: This invention integrates PV / T, heat pumps, and thermal management of electric construction machinery, utilizing solar photovoltaic thermal technology and vehicle thermal management technology to meet the cold, heat, and electrical energy needs of electric construction machinery. The generated electricity can provide power during the day and simultaneously replenish the power battery, extending its range. In winter, the system effectively solves the problem of low-temperature starting and provides heating for the cab, while recovering heat generated by the three-electric system (battery, motor, and electronic control) for cab heating. In summer, during high temperatures, it provides cooling for the cab and dissipates heat from the three-electric system (battery, motor, and electronic control), ensuring stable equipment operation. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the principle structure of a PV / T heat pump energy supply system applied to electric engineering machinery, as an example.
[0017] Figure 2 This is a schematic diagram of the module principle of a heat pump in a PV / T heat pump energy supply system applied to electric engineering machinery, as an example. Detailed Implementation
[0018] The present invention will be further described below with reference to embodiments. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention. After reading this description, any modifications of this description in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.
[0019] Please combine Figure 1As shown in the figure, the PV / T heat pump power supply system for electric construction machinery involved in the embodiment of the present invention includes a PV / T module, a heat storage tank 2, a heat pump 3, and a heat exchange device 4 for the three-electric system, and is applied to an electric loader. It should be noted that the system can also be applied to other electric construction machinery with three-electric systems.
[0020] The PV / T module has photovoltaic cells and a heat collection panel, wherein the photovoltaic cells can be any one or more combinations of monocrystalline silicon cells, polycrystalline silicon cells, and perovskite cells. It is connected to the integrated inverter 5 to provide power to the system, including but not limited to directly charging the power battery, powering the heat pump 3 and various pumps in the system. When the power generated by the PV / T module is insufficient, the power battery supplies power to the entire vehicle, achieving simultaneous operation and charging.
[0021] The solar collector of a PV / T module has heat exchange channels that allow heat to be released to the outside through the flow of the working fluid within, while also providing heat dissipation for the photovoltaic cells to maintain their photoelectric conversion efficiency. The heat exchange channels of the solar collector are connected to the first medium channel 201 of the heat storage tank 2 via a first pipe 6, forming a first circulation loop. The medium in the first circulation loop is water, but other cooling media can also be used. Heat is transferred to the heat storage tank 2 through the first circulation loop. A first water pump 7 and a shut-off valve 10 are installed on the first pipe 6 to control the flow of the working fluid in the first circulation loop.
[0022] The heat storage tank 2 operates using water as the heat storage medium. The outlet of the second medium channel 202 of the heat storage tank 2 is connected to the heat pump 3 via a second pipe 19, and then the heat pump 3 is connected to the inlet of the second medium channel 202 via a third pipe 20, forming a second circulation loop. In the heat storage tank 2, the water in the second medium channel 202 exchanges heat with the water in the first medium channel 201, thereby storing the heat output from the collector plate, which is then supplied to the heat pump 3 as a heat source. A second water pump 8 is installed on the second pipe 19 to control the flow of the working medium in the second circulation loop.
[0023] The heat exchange device 4 of the three-electric system provides preheating and heat dissipation for the power battery, motor, and electronic control system. The heat exchange structures on the power battery, motor, and electronic control system can be connected in series, in parallel, or a combination of both. The illustration in this embodiment shows a series connection. The outlet of the heat exchange device 4 is connected to the heat pump 3 through the fourth pipe 21, and then from the heat pump 3 is connected to the inlet of the heat exchange device 4 through the fifth pipe 22. A third water pump 9 is installed on the fourth pipe 21 to control the flow of the working fluid in the third circulation loop.
[0024] On the second pipeline 19, a first three-way valve 11 is installed after the second water pump 8, and a third three-way valve 13 is installed on the fifth pipeline 22. The bypass outlet c of the first three-way valve 11 is connected to the bypass inlet c of the third three-way valve 13, forming an openable and closable first bypass 23. A second three-way valve 12 is installed on the third pipeline 20, and a fourth three-way valve 14 is installed on the fourth pipeline 21 before the third water pump 9. The bypass inlet c of the second three-way valve 12 is connected to the bypass outlet c of the fourth three-way valve 14, forming an openable and closable second bypass 24. Based on the aforementioned pipeline connections, the working fluid in the second medium channel 202 can flow to the heat pump 3 for circulation or flow to the three-electric system for circulation under the coordinated operation of the second water pump 8 and the first three-way valve 11, the second three-way valve 12, the third three-way valve 13, and the fourth three-way valve 14. The working fluid of the heat exchange device 4 in the three-electric system can flow to the heat pump 3 for circulation or flow to the heat storage tank 2 for circulation, under the cooperation of the third water pump 9 and the first three-way valve 11, the second three-way valve 12, the third three-way valve 13 and the fourth three-way valve 14.
[0025] Please combine Figure 2 As shown in the figure, the working fluid flow of heat pump 3 is illustrated in the cab heating mode. Heat pump 3 includes a compressor 301, a four-way reversing valve 302, a first heat exchanger 303, a throttle valve 305, a second heat exchanger 304, and a gas-liquid separator 306. Taking the heating operation of heat pump 3 as an example, the first heat exchanger 303 is the condensation side, and the second heat exchanger 304 is the evaporation side. The connection of each module of heat pump 3 is the same as that of heat pump 3 in the prior art, and will not be described again. In this invention, in addition to forming a heat exchange structure with the cab of the electric loader, the first heat exchanger 303 is also provided with a first heat exchange pipe 25 and a third heat exchange pipe 27, which exchange heat with both respectively. The second heat exchanger 304, in addition to forming a heat exchange structure with the outside air, is also provided with a second heat exchange pipe 26 and a fourth heat exchange pipe 28, which exchange heat with both respectively.
[0026] After the second pipe 19 is connected to the heat pump 3, it is connected to the inlet a of the fifth three-way valve 15. The first outlet b and the second outlet c of the fifth three-way valve 15 are connected to the inlets of the first heat exchange pipe 25 and the second heat exchange pipe 26, respectively. The outlets of the first heat exchange pipe 25 and the second heat exchange pipe 26 are connected to the first inlet b and the second inlet a of the sixth three-way valve 16, respectively. The outlet c of the sixth three-way valve 16 is connected to the third pipe 20. In this way, the second circulation loop is formed within the heat pump 3 through either the first heat exchange pipe 25 or the second heat exchange pipe 26.
[0027] After the fourth pipe 21 is connected to the heat pump 3, it is connected to the inlet a of the seventh three-way valve 17. The first outlet b and the second outlet c of the seventh three-way valve 17 are connected to the inlet of the third heat exchange pipe 27 and the inlet of the fourth heat exchange pipe 28, respectively. The outlets of the third heat exchange pipe 27 and the fourth heat exchange pipe 28 are connected to the first inlet b and the second inlet a of the eighth three-way valve 18, respectively. The outlet c of the eighth three-way valve 18 is connected to the fifth pipe 22. In this way, the third circulation loop forms a path within the heat pump 3 through the third heat exchange pipe 27 or through the fourth heat exchange pipe 28.
[0028] The PV / T heat pump 3 energy supply system applied to electric engineering machinery in this embodiment works as follows: In scenario one, during winter, the three-electric system is preheated at low temperatures. The first temperature threshold is set to 50℃, and the second temperature threshold is set to 40℃. When the hot water temperature in the second medium channel 202 of the heat storage tank 2 exceeds the first temperature threshold, it operates directly in the first mode: preheating is directly supplied by PV / T. The bypass outlet c of the first three-way valve 11, the bypass inlet c of the third three-way valve 13, the bypass outlet c of the fourth three-way valve 14, and the bypass inlet c of the second three-way valve 12 are opened. The heat pump 3 does not work, allowing the hot water in the second medium channel 202 to directly enter the heat exchange device 4 of the three-electric system for preheating and then flow back to the heat storage tank 2, achieving preheating of the three-electric system without power consumption. During the preheating process, when the hot water temperature in the second medium channel 202 of the heat storage tank 2 is lower than the second temperature threshold, it operates in the second mode: the PV / T supply and air are used as dual heat sources for preheating, and the bypass outlet c of the first three-way valve 11, the bypass inlet c of the third three-way valve 13, the bypass outlet c of the fourth three-way valve 14, and the bypass inlet c of the second three-way valve 12 are closed. The heat pump 3 operates by switching through the four-way reversing valve 302, so that the first heat exchanger 303 is the condensing side, the second heat exchanger 304 is the evaporating side, the first outlet b of the fifth three-way valve 15 is closed and the second outlet c is open, the first inlet b of the sixth three-way valve 16 is closed and the second inlet a is open, the second circulation loop passes through the second heat exchanger 304, the first outlet b of the seventh three-way valve 17 is open and the second outlet c is closed, the first inlet b of the eighth three-way valve 18 is open and the second inlet a is closed, the third circulation loop passes through the first heat exchanger 303, and the heat exchange structure formed by the second heat exchanger 304 on the outside air side operates. In this way, the heat energy of the air and the working fluid in the second circulation loop is absorbed by the heat pump 3 through the second heat exchanger 304, and then released to the working fluid in the third circulation loop through the first heat exchanger 303, thereby preheating the three-electric system. In winter, if the first mode is not used and the hot water temperature in the second medium channel 202 of the heat storage tank 2 does not exceed the first temperature threshold, the second mode is used directly.
[0029] Scenario 2: After starting in winter, heat dissipation is required for the three-electric system and heating for the cab. Heat pump 3 operates by switching the operation of the four-way reversing valve 302, making the first heat exchanger 303 the condenser side and the second heat exchanger 304 the evaporator side. The first outlet b of the fifth three-way valve 15 is closed and the second outlet c is open; the first inlet b of the sixth three-way valve 16 is closed and the second inlet c is open, allowing the second circulation loop to pass through the second heat exchanger 304; the first outlet b of the seventh three-way valve 17 is closed and the second outlet c is open; the first inlet b of the eighth three-way valve 18 is closed and the second inlet a is open, allowing the third circulation loop to pass through the second heat exchanger 304. The heat exchange structure formed by the second heat exchanger 304 on the outside air side is operational, as is the heat exchange structure formed by the first heat exchanger 303 and the cab. In this way, the heat pump 3 absorbs the heat energy from the air, the working fluid in the second circulation loop, and the working fluid in the third circulation loop through the second heat exchanger 304, and then releases it to the heat exchange structure formed by the first heat exchanger 303 and the cab, thus heating the cab.
[0030] Scenario 3: In summer, heat dissipation is needed for the three-electric system and cooling for the cab. Heat pump 3 operates by switching the operation of the four-way reversing valve 302, making the first heat exchanger 303 the evaporator side and the second heat exchanger 304 the condenser side. The first outlet b of the fifth three-way valve 15 is open and the second outlet c is closed; the first inlet b of the sixth three-way valve 16 is open and the second inlet a is closed; the second circulation loop passes through the first heat exchanger 303. The first outlet b of the seventh three-way valve 17 is open and the second outlet c is closed; the first inlet b of the eighth three-way valve 18 is open and the second inlet a is closed; the third circulation loop passes through the first heat exchanger 303. The heat exchange structure formed by the second heat exchanger 304 on the outside air side is operational, as is the heat exchange structure formed between the first heat exchanger 303 and the cab. In this way, the heat pump 3 absorbs the heat energy of the cab, the working fluid in the second circulation loop, and the working fluid in the third circulation loop through the first heat exchanger 303, and then releases it to the heat exchange structure formed on the outside air side through the second heat exchanger 304, thereby cooling the cab.
[0031] Compared to the method of using a heat pump for direct preheating and cooling, this embodiment has the advantages of high energy efficiency and low energy consumption, specifically reflected in: 1. Utilize energy in a cascade manner to improve the overall energy efficiency of the system. The thermal storage tank 2 provides the first-stage low-grade heat energy (PV / T direct supply) to the three-electric system. The heat pump 3 is only activated when the temperature of the hot water storage tank is insufficient to provide the second-stage high-grade heat energy. This realizes the priority utilization of solar thermal energy and avoids the meaningless start-up of the heat pump 3 in the medium-temperature preheating range, which greatly reduces the energy consumption ratio of the heat pump 3 for heating. In contrast, the traditional direct heat pump supply mode requires the heat pump to do work for heating / cooling throughout the process. Even if there is a solar thermal source, it cannot be directly utilized, resulting in the waste of high-grade energy.
[0032] 2. Highly integrated system piping The heat exchange structure of the three-electric system shares a three-way reversing valve 302 and each water pump with the main heat exchange pipeline of the PV / T heat pump system. There is no need to set up separate independent pipelines, valves and heat exchange interfaces for heat pump heating / cooling for the three-electric system, which reduces the number of pipeline interfaces and resistance. At the same time, the PTC preheating module, independent air conditioning radiator in the cab and dedicated radiator of the three-electric system of traditional electric loaders are eliminated. The heat exchange requirements of preheating / cooling of the three-electric system and heating and cooling of the cab are all integrated into heat pump 3, reducing the core heat exchange / preheating equipment.
[0033] 3. Fast thermal response, suitable for the working conditions of construction machinery operating outdoors. The PV / T direct supply mode provides instant heat flow to the three electric components, eliminating the need to wait for the compressor 301 of the heat pump 3 to start and the four-way reversing valve 302 to switch, thus meeting the rapid start-up needs of electric loaders in open-pit mines, high-altitude environments, and other scenarios. In contrast, the traditional heat pump direct supply mode suffers from compressor start-up delays and pipeline heat exchange preheating issues, which cannot meet the rapid operation requirements of construction machinery at low temperatures.
[0034] 4. Flexible load matching, adaptable to the heating requirements of the three main electrical systems and the cab. The thermal management needs of the three-electric system and the cab are distributed through the same set of pipes and valves. The heat energy can be distributed on demand by switching the three-way valve according to the working status of the three-electric system (start-up / operation / high load) and the heating and cooling needs of the cab. In the traditional direct supply mode, the three-electric system and the cab are independent heat pump circuits, which cannot achieve joint distribution of heat energy and are prone to situations where one side has an excess of heat source and the other side has an insufficient heat source.
Claims
1. A PV / T heat pump energy supply system for electric engineering machinery, characterized in that, The system includes a PV / T module, a heat storage tank, a heat pump, and a heat exchange device for a three-electric system. The heat exchange channel of the PV / T module's heat collection plate and the first medium channel of the heat storage tank form a first circulation loop. The second medium channel of the heat storage tank forms a second circulation loop, and the heat exchange device for the three-electric system forms a third circulation loop. Both the second and third circulation loops extend to the heat pump. The working fluid of the second circulation loop and the third circulation loop can be switched to form a heat exchange structure with either the first or second heat exchanger of the heat pump. The cab of the electric engineering machinery forms a heat exchange structure with the first heat exchanger. The second heat exchanger forms a heat exchange structure on the outside air side. The outlet of the second medium channel is connected to the inlet of the heat exchange device for the three-electric system through an openable and closable first bypass. The outlet of the heat exchange device for the three-electric system is connected to the inlet of the second medium channel through an openable and closable second bypass. The heat exchange directions of the first and second heat exchangers are opposite and change simultaneously when the heat pump changes its operating mode.
2. The PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, In the second circulation loop, a first three-way valve is installed on the pipeline from the outlet of the second medium channel to the heat pump, and a second three-way valve is installed on the pipeline from the inlet of the second medium channel to the heat pump; in the third circulation loop, a third three-way valve is installed on the pipeline from the inlet of the heat exchange device of the three-electric system to the heat pump, and a fourth three-way valve is installed on the pipeline from the outlet of the heat exchange device of the three-electric system to the heat pump, the bypass outlet of the first three-way valve is connected to the bypass inlet of the third three-way valve, and the bypass inlet of the second three-way valve is connected to the bypass outlet of the fourth three-way valve.
3. The PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, The first heat exchanger is provided with a first heat exchange pipeline, and the second heat exchanger is provided with a second heat exchange pipeline. The inlet ends of the first heat exchange pipeline and the second heat exchange pipeline are respectively connected to the first outlet and the second outlet of the fifth three-way valve. The outlet ends of the first heat exchange pipeline and the second heat exchange pipeline are respectively connected to the first inlet and the second inlet of the sixth three-way valve. The inlet of the fifth three-way valve and the outlet of the sixth three-way valve respectively constitute the second circulation loop extending to the connection port of the heat pump.
4. The PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, The first heat exchanger is provided with a third heat exchange pipeline, and the second heat exchanger is provided with a fourth heat exchange pipeline. The inlet ends of the third heat exchange pipeline and the fourth heat exchange pipeline are respectively connected to the first outlet and the second outlet of the seventh three-way valve. The outlet ends of the third heat exchange pipeline and the fourth heat exchange pipeline are respectively connected to the first inlet and the second inlet of the eighth three-way valve. The inlet of the seventh three-way valve and the outlet of the eighth three-way valve respectively constitute the third circulation loop extending to the connection port of the heat pump.
5. A PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, The system includes an integrated inverter unit, through which the photovoltaic cells of the PV / T module supply power to the electrical equipment of the system and charge the power battery of the three-electric system.
6. A PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, The photovoltaic cells of the PV / T module are any one or more combinations of monocrystalline silicon cells, polycrystalline silicon cells, and perovskite cells.
7. A PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, The working fluid in the heat exchange channel of the collector plate of the PV / T module is water.
8. A PV / T heat pump energy supply system for electric engineering machinery according to claim 1, characterized in that, The electric construction machinery mentioned is an electric loader.
9. A method for operating a PV / T heat pump energy supply system applied to electric engineering machinery as described in any one of claims 1 to 8, characterized in that, include: When the three-electric system needs preheating, it operates in either a first mode or a second mode. In the first mode, the heat pump is not working, and the working fluid in the second medium channel enters the heat exchange device of the three-electric system through the first bypass to release heat, and then flows back to the second medium channel through the second bypass. In the second mode, the first bypass and the second bypass are closed, the second circulation loop forms a heat exchange structure with the second heat exchanger, the third circulation loop forms a heat exchange structure with the first heat exchanger, the heat pump works and absorbs heat from the second circulation loop and the outside air on the evaporation side of the second heat exchanger, and releases heat to the third circulation loop on the condensation side of the first heat exchanger. When the three-electric system needs heat dissipation and the cab needs heating, the first bypass and the second bypass are closed, the second circulation loop forms a heat exchange structure with the second heat exchanger, the third circulation loop forms a heat exchange structure with the second heat exchanger, the heat pump works and absorbs heat from the second circulation loop, the third circulation loop and the outside air with the second heat exchanger as the evaporation side, and releases heat to the cab with the first heat exchanger as the condensation side. When the three-electric system needs heat dissipation and the cab needs cooling, the first bypass and the second bypass are closed, the second circulation loop forms a heat exchange structure with the first heat exchanger, the third circulation loop forms a heat exchange structure with the first heat exchanger, the heat pump works and absorbs heat from the second circulation loop, the third circulation loop and the cab as the evaporation side of the first heat exchanger, and releases heat to the outside air as the condensation side of the second heat exchanger.
10. The working method of a PV / T heat pump energy supply system applied to electric engineering machinery according to claim 9, characterized in that, When the three-electric system needs to be preheated, a first temperature threshold and a second temperature threshold are set. When the working fluid temperature of the second medium channel exceeds the first temperature threshold, it operates in the first mode. When the working fluid temperature of the second medium channel is lower than the second temperature threshold, it switches to the second mode. When it does not operate in the first mode and the working fluid temperature of the second medium channel is lower than the first temperature threshold, it operates in the second mode.