Photovoltaic air source-water source heat pump drying system with energy storage function

Abstract

The utility model relates to the technical field of drying, in particular to a photovoltaic air source-water source heat pump drying system with energy storage, which comprises an air source heat pump unit and a drying box, the air source heat pump unit consists of a compressor, a condenser, an evaporator and a fan, the compressor is connected with a photovoltaic power generation unit, the condenser is mounted in the drying box, and the evaporator is mounted in the drying box. A water source heat pump unit is arranged on a pipeline between the evaporator and the condenser and connected with a main controller. Compared with the prior art, energy of sunlight is converted into heat of water to be stored in the water source heat pump unit in the daytime in plateau areas, severe cold areas and areas with large day and night temperature difference, and when the air temperature drops and the heating performance of the air source heat pump unit is attenuated at night, the heat in the water source heat pump unit is released, so that stable heating of the heat pump unit is guaranteed; and stable energy supply in the drying box is maintained, and the quality of dried materials is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of drying, in particular to a photovoltaic air source - water source heat pump drying system with energy storage. Background Art

[0002] Traditional material drying and dehumidification generally adopt natural drying or heating drying. Open - air natural drying has low efficiency, large floor area, is vulnerable to weather influence, consumes a large amount of manpower and material resources, is also vulnerable to pollution by dust and insects, and it is difficult to guarantee the quality of dried agricultural and sideline products. Although fossil fuel drying is not restricted by the above - mentioned objective factors, the fossil fuels required for drying, on the one hand, cause environmental pollution, and on the other hand, some components of fossil fuels will pollute the dried products, affecting the quality of agricultural and sideline products. Under the dual crises of environment and energy, reducing the use of fossil fuels and actively developing new energy are the inevitable trends in the development of the green drying industry.

[0003] Heat pump drying technology is a technology that uses electrical energy and a heat pump device to transfer heat from a low - temperature heat source to a high - temperature heat source. One unit of electricity can transfer several units of heat. Compared with general electric heating drying, it can save more than 50% of energy consumption. At the same time, it can have the dual effects of condenser heating and evaporator dehumidification, and is the future development direction of drying technology.

[0004] However, for areas with high altitude, severe cold and large temperature differences between day and night, solar direct drying is affected by the environment. At the same time, after the ambient temperature drops below 0°C for a conventional air - source heat pump, the heating performance of the unit fluctuates and decays, the temperature of the drying room drops significantly. When the ambient temperature continuously drops to the dew point temperature of the air, the evaporator will frost, the compression ratio of the compressor increases, and the exhaust temperature of the compressor rises sharply, resulting in the system alarming and shutting down. In view of this, the present utility model is specifically proposed. Summary of the Utility Model

[0005] In order to overcome the above - mentioned technical defects, the utility model provides a photovoltaic air source - water source heat pump drying system with energy storage, which can provide sufficient heat for the evaporation end under low - temperature conditions, ensure the stable operation and heating of the heat pump unit, and solve the problem that the traditional heat pump drying system cannot continuously dry at night under high - cold and large - temperature - difference conditions.

[0006] The technical solution adopted by the utility model is as follows: A photovoltaic air source - water source heat pump drying system with energy storage, comprising an air - source heat pump unit composed of a compressor, a condenser, an evaporator, and a fan, and a drying box. The compressor is connected to a photovoltaic power generation unit. The condenser is installed in the drying box. A water - source heat pump unit is provided on the pipeline between the evaporator and the condenser, and the water - source heat pump unit is connected to a main controller.

[0007] In a specific solution, the evaporator is a finned-tube evaporator and the condenser is a finned-tube condenser.

[0008] Specifically, according to the working conditions of high altitude, severe cold, and large temperature difference, the main controller controls the opening and closing of the water source heat pump unit, combines air energy and water heat energy, ensures that the heat pump unit can stably generate heat under high cold and large temperature difference, and at the same time ensures that the drying process can proceed continuously. The photovoltaic power generation unit provides electric energy for the stable operation of the air source heat pump unit.

[0009] Further, the water source heat pump unit includes a water storage tank, in which a condensing coil and a water-cooled evaporator are provided. The condensing coil is communicated with the evaporator and the condenser respectively through a first pipeline, and the water-cooled evaporator is communicated with the evaporator and the condenser respectively through a second pipeline. A first solenoid valve and a second solenoid valve are installed on the first pipeline and the second pipeline respectively, and both the first solenoid valve and the second solenoid valve are connected to the main controller.

[0010] In a specific solution, both the first solenoid valve and the second solenoid valve are four-way valves.

[0011] Specifically, when the sunlight is sufficient during the day, the first solenoid valve and the second solenoid valve are switched to form an air source heat pump drying energy storage system composed of a water storage tank, an evaporator, a compressor, a condenser, and a blower. The working medium absorbs heat from the air through the evaporator, part of it releases heat to the drying box 14 through the condenser, and the other part heats the water in the water storage tank through the condensing coil and stores it as the heat of water. When the air temperature drops at night and the heating performance of the air source heat pump unit decays, the first solenoid valve and the second solenoid valve are switched to form a water source heat pump drying system composed of a water storage tank, a water-cooled evaporator, a compressor, a condenser, and a blower. The working medium absorbs heat from the hot water in the water storage tank through the water-cooled evaporator, and after the compressor raises the temperature and pressure, it releases heat to the drying box through the condenser. The heat stored during the day is taken out for the heat pump unit to use, so that the heat pump unit does not operate or reduces the operation time under adverse working conditions, improves the heating performance of the heat pump unit under high cold and large temperature difference, and ensures the drying quality of the materials.

[0012] Further, a first expansion valve is provided on the first pipeline, and the first expansion valve is located between the condensing coil and the evaporator.

[0013] Specifically, the working medium absorbs heat from the air through the evaporator, after the compressor raises the temperature and pressure, it releases heat through the condenser and the condensing coil, and returns to the evaporator after cooling and depressurizing through the first expansion valve, and circulates in this way.

[0014] Further, a second expansion valve is provided on the second pipeline. The second expansion valve is located between the water-cooled evaporator and the condenser. One end of the second pipeline is communicated with the first pipeline through a first electromagnetic valve, and the other end of the second pipeline is communicated with the evaporator through a second electromagnetic valve.

[0015] Specifically, the working medium absorbs heat from the hot water in the water storage tank through the water-cooled evaporator, is heated and pressurized by the compressor, releases heat to the drying box through the condenser, and then returns to the water-cooled evaporator after being cooled and depressurized by the second expansion valve, thus circulating.

[0016] Further, a temperature sensor is further included. The temperature sensor is arranged close to the evaporator, and the temperature sensor is connected to the main controller.

[0017] Specifically, the ambient temperature around the evaporator is monitored by the temperature sensor. When the surface temperature of the evaporator is lower than the set temperature, the main controller controls the switching of the first electromagnetic valve and the second electromagnetic valve, so that the evaporation end switches from absorbing heat from the air to absorbing heat from the water storage tank, improves the attenuated heating performance of the heat pump unit, and ensures the internal energy demand of the drying box.

[0018] Further, the photovoltaic power generation unit includes multiple groups of solar power generation components and a photovoltaic power generation controller. The solar power generation components, the photovoltaic power generation controller and the compressor are electrically connected.

[0019] Specifically, multiple groups of solar power generation components are connected in series and fixedly installed in an open and unobstructed area facing south. The solar power generation components are connected to the photovoltaic power generation controller and drive the compressor to work.

[0020] Further, the drying box is made of heat preservation plates, and a material rack, a material tray and a circulating fan are installed in the drying box.

[0021] In a specific solution, the drying box is a rectangular box body spliced by polyurethane heat preservation plates, and there are four circulating fans. The four circulating fans are respectively placed at the four corners of the rectangular box body.

[0022] Specifically, the air source heat pump unit provides heat energy for the drying box, and the circulating fan helps the hot air in the drying box to circulate, so that the materials placed in the material tray are evenly heated and dried.

[0023] Further, a water mixer is installed at the bottom of the water storage tank.

[0024] In a specific solution, the water mixer is a stirrer, and the heat of the hot water in the water storage tank is made uniform by stirring, so as to continuously provide heat for the water-cooled evaporator.

[0025] Further, a low-pressure gauge and a high-pressure gauge are further included. The low-pressure gauge is located on the pipeline between the compressor and the evaporator, and the high-pressure gauge is located on the pipeline between the compressor and the condenser. Specifically, it is used to monitor the operating stability of the working medium in the air source heat pump unit.

[0026] Beneficial effects: The provided photovoltaic air source-water source heat pump drying system with energy storage can convert the energy of sunlight into the heat of water during the day and store it in the water source heat pump unit in areas with high altitudes, severe cold, and large temperature differences between day and night. When the air temperature drops at night and the heating performance of the air source heat pump unit decays, by releasing the heat in the water source heat pump unit, the stable heating of the heat pump unit can be ensured, the stable energy supply inside the drying oven can be maintained, and the quality of the dried materials can be guaranteed. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the present invention. Specific Embodiments

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention. It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0029] Please refer to Figure 1, in an embodiment of the present utility model, a photovoltaic air source - water source heat pump drying system with energy storage is provided, which includes an air source heat pump unit composed of a compressor 4, a condenser 16, an evaporator 7, and a fan, and a drying box 14. The compressor 4 is connected to a photovoltaic power generation unit. The condenser 16 is installed in the drying box 14. A water source heat pump unit is provided on the pipeline between the evaporator 7 and the condenser 16, and the water source heat pump unit is connected to a main controller;

[0030] In a more optimal specific embodiment, the evaporator 7 is a finned - tube evaporator, the condenser 16 is a finned - tube condenser, and both the finned - tube evaporator and the finned - tube condenser are configured with fans. According to the working conditions of high altitude, severe cold, and large temperature difference, the opening and closing of the water source heat pump unit are controlled by the main controller, combining air energy and water heat energy to ensure that the heat pump unit can stably heat under high - cold and large - temperature - difference conditions, and at the same time ensure that the drying process can proceed continuously. The photovoltaic power generation unit provides electric energy for the stable operation of the air source heat pump unit.

[0031] In a specific embodiment, the water source heat pump unit includes a water storage tank 11. A condensation coil 10 and a water - cooled evaporator 12 are provided in the water storage tank. The condensation coil 10 is respectively communicated with the evaporator 7 and the condenser 16 through a first pipeline 19. The water - cooled evaporator 12 is respectively communicated with the evaporator 7 and the condenser 16 through a second pipeline 20. A first solenoid valve 18 and a second solenoid valve 6 are respectively installed on the first pipeline 19 and the second pipeline 20. Both the first solenoid valve 18 and the second solenoid valve 6 are connected to the main controller;

[0032] In a more optimal specific embodiment, both the first solenoid valve 18 and the second solenoid valve 6 are four - way valves. When the sunlight is sufficient during the day, the first solenoid valve and the second solenoid valve are switched, so that the water storage tank, the evaporator, the compressor, the condenser, and the fan form an air source heat pump drying energy - storage system. The working medium absorbs heat from the air through the evaporator. Part of the heat is released to the drying box through the condenser, and the other part heats the water in the water storage tank through the condensation coil, converting it into the heat of water for storage. When the air temperature drops at night and the heating performance of the air source heat pump unit decays, the first solenoid valve and the second solenoid valve are switched, so that the water storage tank, the water - cooled evaporator, the compressor, the condenser, and the fan form a water source heat pump drying system. The working medium absorbs heat from the hot water in the water storage tank through the water - cooled evaporator, and after the compressor raises the temperature and pressure, it releases heat to the drying box through the condenser;

[0033] The heat stored during the day is taken out for the use of the heat pump unit, so that the heat pump unit does not operate or reduces the operation time under adverse working conditions, improving the heating performance of the heat pump unit under high - cold and large - temperature - difference conditions and ensuring the drying quality of the materials.

[0034] In a specific embodiment, a first expansion valve 9 is provided on the first pipeline 19, and the first expansion valve 9 is located between the condensation coil 10 and the evaporator 7;

[0035] The working medium absorbs heat from the air through the evaporator, releases heat through the condenser and the condensation coil after the compressor raises the temperature and pressure, and returns to the evaporator after reducing the temperature and pressure through the first expansion valve, thus circulating.

[0036] In a specific embodiment, a second expansion valve 13, a first solenoid valve 18 and a second solenoid valve 6 are provided on the second pipeline 20. The second expansion valve 13 is located between the water-cooled evaporator 12 and the condenser 16. One end of the second pipeline 20 is connected to the first pipeline 19 through the first solenoid valve 18, and the other end of the second pipeline 20 is connected to the evaporator 7 through the second solenoid valve 6. The working medium absorbs heat from the hot water in the water storage tank through the water-cooled evaporator, releases heat to the drying oven through the condenser after the compressor raises the temperature and pressure, and then returns to the water-cooled evaporator after reducing the temperature and pressure through the second expansion valve, thus circulating.

[0037] In a specific embodiment, a temperature sensor is further included. The temperature sensor is arranged close to the evaporator 7, and the temperature sensor is connected to the main controller. The ambient temperature around the evaporator is monitored through the temperature sensor. When the surface temperature of the evaporator is lower than the set temperature, the main controller controls the switching of the first solenoid valve 18 and the second solenoid valve 6, so that the evaporation end switches from absorbing heat from the air to absorbing heat from the water storage tank, improves the attenuated heating performance of the heat pump unit, and ensures the energy demand inside the drying oven.

[0038] In a specific embodiment, the photovoltaic power generation unit includes multiple groups of solar power generation components 1 and a photovoltaic power generation controller 2. The solar power generation components 1, the photovoltaic power generation controller 2 and the compressor 4 are electrically connected. Multiple groups of solar power generation components are connected in series and fixedly installed facing south in an open and unobstructed area. The solar power generation components are connected to the photovoltaic power generation controller and drive the compressor to work.

[0039] In a specific embodiment, the drying oven 14 is made of heat-insulating plates. A material rack, a material tray and a circulation fan 21 are installed in the drying oven 14. In a more optimal specific embodiment, the drying oven is a rectangular box body spliced by polyurethane heat-insulating plates. There are four circulation fans 21, and the four circulation fans 21 are respectively placed at the four corners of the rectangular box body. The air source heat pump unit provides heat energy for the drying oven, and the circulation fan helps the hot air in the drying oven to circulate, so that the materials placed in the material trays are evenly heated and dried.

[0040] In a specific embodiment, a water mixer is installed at the bottom of the water storage tank 11; in a more preferred specific embodiment, the water mixer is a stirrer, which makes the heat of the hot water in the water storage tank uniform by stirring, and continuously provides heat for the water-cooled evaporator.

[0041] In other embodiments, the water mixer can also be an aerator, and its function remains the same, so it will not be elaborated here.

[0042] In a specific embodiment, a low-pressure gauge 3 and a high-pressure gauge 5 are further included. The low-pressure gauge 3 is located on the pipeline between the compressor 4 and the evaporator 7, and the high-pressure gauge 5 is located on the pipeline between the compressor 4 and the condenser 16. Specifically, it is used to monitor the operation stability of the working medium in the air source heat pump unit.

[0043] The following further illustrates the present utility model in combination with a specific application scenario:

[0044] A photovoltaic air source-water source heat pump drying system with energy storage includes a solar power generation component 1, a photovoltaic power generation controller 2, a low-pressure gauge 3, a compressor 4, a high-pressure gauge 5, a second solenoid valve 6, a finned-tube evaporator 7, an evaporation fan 8, a first expansion valve 9, a condensation coil 10, a water storage tank 11, a water-cooled evaporator 12, a second expansion valve 13, a drying box 14, dried materials 15, a finned-tube condenser 16, a condensation fan 17, a first solenoid valve 18, a circulation fan 21, a temperature sensor (not shown in the figure) and a main controller (not shown in the figure); wherein, the finned-tube condenser 16 is configured with a condensation fan 17, the finned-tube evaporator 7 is configured with an evaporation fan 8, and the temperature sensor is arranged close to the evaporator; the water storage tank 11 is installed near the drying box, and the condensation coil 10 and the water-cooled evaporator 12 are fixedly installed in the water storage tank 11. The water-cooled evaporator 12 is connected to the finned-tube condenser 16 through the first solenoid valve 18, and a second expansion valve 13 is arranged between the first solenoid valve 18 and the water-cooled evaporator 12. The condensation coil 10 is connected to the finned-tube evaporator 7, and a first expansion valve 9 is arranged between the condensation coil 10 and the finned-tube evaporator 7. The water-cooled evaporator 12 is connected to the second solenoid valve 6 and is connected to the compressor 4. The finned-tube evaporator 7 is connected to the second solenoid valve 6 and is connected to the compressor 4; the finned-tube condenser 16 of the heat pump unit is installed inside the drying box 14, and circulation fans are installed at the four corners inside the drying box to help the hot air in the drying box circulate. A material rack and a material tray 15 are installed inside the drying box for placing materials.

[0045] In use, the solar power generation components are fixedly installed facing south in an open and unobstructed area. Multiple groups of solar power generation components are connected in series to form a photovoltaic power generation unit. Each solar power generation component 1 is connected to a photovoltaic power controller 2 and drives a compressor 4 to work. During the day when solar radiation is sufficient, the compressor 4 is completely driven by the solar power generation components and the photovoltaic controller 2. When solar radiation is insufficient during the day, mains power is used to supplement and drive the compressor 4 to operate.

[0046] The switching of the heat pump working mode is completed by adjusting the closing directions of the second solenoid valve 6 and the first solenoid valve 18. When there is sufficient sunlight and a relatively high ambient temperature during the day, the air source heat pump drying system is started. The working medium absorbs heat from the air through the finned tube evaporator 7. After the compressor 4 raises the temperature and pressure, it releases heat to the drying box 14 through the finned tube condenser 16, and then heats the water in the water storage tank 11 through the condensation coil 10. Finally, it returns to the finned tube evaporator 7 after reducing the temperature and pressure through the first expansion valve 9, and thus circulates.

[0047] When the ambient temperature continuously decreases at night and the heating performance of the air source heat pump unit decays to the point where it cannot meet the requirements of the drying box, and the surface temperature of the finned tube evaporator 7 is lower than the set temperature, the air source heat pump drying system is switched to a water source heat pump drying system. The working medium absorbs heat from the hot water in the water storage tank 11 through the water-cooled evaporator 12. After the compressor 4 raises the temperature and pressure, it releases heat to the drying box 14 through the finned tube condenser 16, and then returns to the water-cooled evaporator 12 after reducing the temperature and pressure through the second expansion valve 13, and thus circulates.

[0048] When the ambient temperature starts to rise the next day and the heating capacity of the air source heat pump unit can meet the heat required for drying the materials inside the drying box, that is, when the surface temperature of the finned tube evaporator 7 is higher than the set temperature, the second solenoid valves 6 and 18 are controlled to switch directions, and the water source heat pump drying system is switched to an air source heat pump drying system. The working medium absorbs heat from the air through the finned tube evaporator 7. After the compressor 4 raises the temperature and pressure, it releases heat to the drying box 14 through the finned tube condenser 16, and reheats the water in the water storage tank 11 through the condensation coil 10, and thus reciprocally circulates to fully utilize and store the air energy during the day.

[0049] By switching the four-way valve, the air energy and water heat energy are combined to extract the heat stored during the day for use by the heat pump unit, so that the heat pump unit does not operate or reduces its operating time under adverse conditions, improves the heating performance of the heat pump unit under high cold and large temperature differences, maintains the stable energy supply inside the drying box, and ensures the drying quality of the materials.

[0050] Finally, it should be noted that the above description is only the preferred embodiment of the present invention. Those skilled in the art, under the inspiration of the present invention and without violating the purpose and claims of the present invention, can make various similar representations, and such transformations all fall within the protection scope of the present invention.

Claims

1. A photovoltaic air-source - water-source heat pump drying system with energy storage, comprising an air-source heat pump unit composed of a compressor (4), a condenser (16), an evaporator (7), and a fan, and a drying box (14), characterized in that: The compressor (4) is connected to a photovoltaic power generation unit. The condenser (16) is installed in the drying box (14). A water source heat pump unit is provided on the pipeline between the evaporator (7) and the condenser (16), and the water source heat pump unit is connected to a main controller.

2. The photovoltaic air source - water source heat pump drying system with energy storage according to claim 1, characterized in that: The water source heat pump unit includes a water storage tank (11). A condensation coil (10) and a water-cooled evaporator (12) are provided in the water storage tank. The condensation coil (10) is communicated with the evaporator (7) and the condenser (16) respectively through a first pipeline (19). The water-cooled evaporator (12) is communicated with the evaporator (7) and the condenser (16) respectively through a second pipeline (20). A first solenoid valve (18) and a second solenoid valve (6) are respectively installed on the first pipeline (19) and the second pipeline (20). Both the first solenoid valve (18) and the second solenoid valve (6) are connected to the main controller.

3. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 2, characterized in that: A first expansion valve (9) is provided on the first pipeline (19), and the first expansion valve (9) is located between the condensation coil (10) and the evaporator (7).

4. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 2, characterized in that: A second expansion valve (13) is provided on the second pipeline (20), and the second expansion valve (13) is located between the water-cooled evaporator (12) and the condenser (16). One end of the second pipeline (20) is communicated with the first pipeline (19) through a first solenoid valve (18), and the other end of the second pipeline (20) is communicated with the evaporator (7) through a second solenoid valve (6).

5. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 1, characterized in that: It further includes a temperature sensor. The temperature sensor is arranged close to the evaporator (7), and the temperature sensor is connected to the main controller.

6. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 2, characterized in that: The photovoltaic power generation unit includes multiple groups of solar power generation components (1) and a photovoltaic power generation controller (2). The solar power generation components, the photovoltaic power generation controller (2) and the compressor (4) are electrically connected.

7. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 1, characterized in that: The drying box (14) is made of heat-insulating plates. A material rack, a material tray (15) and a circulation fan (21) are installed in the drying box (14).

8. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 2, characterized in that: A water mixer is installed at the bottom of the water storage tank (11).

9. A photovoltaic air-source - water-source heat pump drying system with energy storage according to claim 2, wherein: It further includes a low-pressure gauge (3) and a high-pressure gauge (5). The low-pressure gauge (3) is located on the pipeline between the compressor (4) and the evaporator (7), and the high-pressure gauge (5) is located on the pipeline between the compressor (4) and the condenser (16).

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