Fruit and vegetable processing heat energy comprehensive utilization system utilizing solar energy

Abstract

The invention discloses a fruit and vegetable processing heat energy comprehensive utilization system utilizing solar energy, and relates to the technical field of energy utilization, the fruit and vegetable processing heat energy comprehensive utilization system comprises an electric power supply unit, a heat collection unit, a heat storage unit, a drying unit, a heat pump unit, a cold storage unit, a freezing unit and a greenhouse planting unit, the photovoltaic and photo-thermal integrated system is electrically connected with the power utilization unit, the heat collection unit can collect heat through solar energy, a fluid working medium of the heat collection unit communicates with the heat storage unit through a pipeline, and the heat storage unit can store a heat source transmitted by the heat collection unit and can transmit the heat source to the drying unit. A driving heat source of the heat pump unit comes from the photovoltaic photo-thermal integrated system, a cold source from the heat pump unit is sequentially communicated with the cold storage unit and the freezing unit, and a fluid working medium from the freezing unit and a fluid working medium from the drying unit are communicated with the greenhouse planting unit. Solar energy is converted into electric energy and heat energy which are stored as cold / heat energy, and the purposes of energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of energy utilization, and in particular to a fruit and vegetable processing heat energy comprehensive utilization system utilizing solar energy. Background Art

[0002] The main methods of drying agricultural products can be roughly divided into four types: natural drying, freeze drying, hot air drying and solar drying. The quality and efficiency of fruit and vegetable drying are affected by drying temperature and drying time. Generally, the higher the drying temperature and the shorter the drying time, the more effectively the shrinkage rate and hardness of the dried fruit can be reduced, and the rehydration and toughness can be enhanced.

[0003] In order to increase the yield of fruit and vegetable drying, hot air drying is currently the main method in the field of fruit and vegetable drying, which mainly uses coal, electricity and other basic energy sources to generate high-temperature air of about 60℃-150℃ for fruit and vegetable drying. The solar drying method mainly allows the dried object to directly or indirectly absorb the heat energy of solar radiation, and achieves the drying of crops through convection heat transfer. For example, through solar collectors, high-temperature air of about 150℃ can be obtained for fruit and vegetable drying, thereby effectively shortening the drying time and making the taste of agricultural products the best. As a renewable energy source, solar radiation is limited by weather and time. On cloudy days or at night, it cannot meet the needs of 24-hour continuous drying of crops, thus affecting the quality and yield of agricultural products.

[0004] In response to the problems existing in solar fruit and vegetable drying, the existing technology can provide heat energy through solar thermal collection to achieve fruit and vegetable drying, but the utilization of heat energy is relatively simple, and there is no reasonable cascade utilization of the waste heat after drying to improve the comprehensive utilization efficiency of renewable energy in agricultural systems. Summary of the invention

[0005] The purpose of the present invention is to provide a fruit and vegetable processing heat energy comprehensive utilization system using solar energy to solve the problems existing in the above-mentioned prior art, so that the heat energy in the fruit and vegetable processing process can be comprehensively utilized to achieve energy saving and emission reduction.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a fruit and vegetable processing heat energy comprehensive utilization system utilizing solar energy, comprising a power supply unit, a heat collection unit, a heat storage unit, a drying unit, a heat pump unit, a cold storage unit, a freezing unit and a greenhouse planting unit, wherein the power supply unit comprises a photovoltaic-thermal integrated system, the photovoltaic-thermal integrated system is electrically connected to the heat collection unit, the heat storage unit, the drying unit, the heat pump unit, the cold storage unit and the freezing unit, the heat collection unit can utilize solar energy to collect heat, the fluid working medium of the heat collection unit is connected with the heat storage unit through a pipeline, the heat storage unit can store the heat source transferred from the heat collection unit and can transfer it to the drying unit, the drying unit is used for drying fruits and vegetables, the driving heat source of the heat pump unit comes from the photovoltaic-thermal integrated system, the cold source from the heat pump unit is connected with the cold storage unit and the freezing unit in sequence, the fluid working medium after the freezing unit exchanges heat with juice and the fluid working medium from the drying unit are both connected with the greenhouse planting unit, and the greenhouse planting unit is connected with the outside atmosphere.

[0008] Preferably, the freezing unit and the drying unit are both connected to a buffer tank through pipelines, and a temperature sensor and a humidity sensor are provided in the buffer tank and the greenhouse planting unit. The set temperature of the greenhouse planting unit is 15°C-25°C.

[0009] Preferably, the buffer tank is connected to the outside atmosphere, and a valve is provided on each of the four pipelines connected to the buffer tank.

[0010] Preferably, the power supply unit also includes a backup power supply, which is an external power supply; the photovoltaic thermal integration system is connected to a battery, and a heat exchanger is provided on the photovoltaic thermal integration system. The fluid working medium in the heat exchanger exchanges heat with the photovoltaic thermal module in the photovoltaic thermal integration system, and the low-grade heat source coming out of the heat exchanger is connected to the heat pump unit.

[0011] Preferably, the heat collection unit is a concentrating solar collector, which includes a concentrator, a heat collecting tube, a porous heat absorbing material and a fluid working medium. The concentrator is used to concentrate and reflect sunlight onto the heat collecting tube, and the heat collecting tube is provided with the porous heat absorbing material. The fluid working medium is gas or liquid, and the heat collecting tube is connected to the source of the fluid working medium through a fan or a pump body.

[0012] Preferably, the heat storage unit comprises a heat storage tank body and a heat storage medium, wherein the heat storage tank body is provided with a heat storage medium for storing heat, and the heat storage medium is a material with high thermal conductivity and high temperature resistance.

[0013] Preferably, the heat storage medium includes at least one of ceramsite, rock, sand and stainless steel balls.

[0014] Preferably, the drying unit is a drying box, and the temperature of the drying box is set to 50°C-150°C.

[0015] Preferably, the cold source from the heat pump unit is liquid, and the cold storage unit is a phase change cold storage device, which stores the cold source from the heat pump unit in the form of ice slurry or ice-water mixture, and the phase change cold storage device provides a cold source for the refrigeration unit.

[0016] Preferably, the heat storage unit, the drying unit, the cold storage unit, the freezing unit and the greenhouse planting unit can be arranged in parallel or in series in several groups at corresponding positions.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] The present invention converts solar energy into electrical energy and thermal energy, and at the same time provides continuous cold / heat energy for fruit and vegetable processing and cultivation through heat storage and cold storage units, thereby realizing continuous and cascade utilization of renewable energy in the fruit and vegetable comprehensive utilization system, and effectively achieving the purpose of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the flow of a comprehensive utilization system of heat energy for fruit and vegetable processing using solar energy in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structural connection relationship of the heat collection unit in an embodiment of the present invention;

[0022] In the figure: 1- photovoltaic thermal integration system, 2- heat collection unit, 3- heat storage tank, 4- drying box, 5- buffer tank, 6- greenhouse cultivation room, 7- heat pump unit, 8- phase change cold storage device, 9- refrigeration unit, 10- heat storage medium, 11- backup power supply, 12- heat collection tube, 13- fan, 14- porous heat absorption material, 15- valve, 16- temperature sensor, 17- humidity sensor, 18- concentrator. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a fruit and vegetable processing heat energy comprehensive utilization system using solar energy to solve the problems existing in the prior art, so that the heat energy in the fruit and vegetable processing process can be comprehensively utilized to achieve energy saving and emission reduction.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1 to Figure 2 As shown, in this embodiment, a fruit and vegetable processing heat energy comprehensive utilization system using solar energy is provided, including a power supply unit, a heat collection unit 2, a heat storage unit, a drying unit, a heat pump unit 7, a cold storage unit, a freezing unit 9 and a greenhouse planting unit. The power supply unit includes a photovoltaic thermal integration system 1, and the photovoltaic thermal integration system 1 is electrically connected to the heat collection unit 2, the heat storage unit, the drying unit, the heat pump unit 7, the cold storage unit and the freezing unit 9. The heat collection unit 2 can collect heat using solar energy, and the fluid working medium of the heat collection unit 2 is connected to the heat storage unit through a pipeline. The heat storage unit can store the heat source transferred from the heat collection unit 2 and can be transferred to the drying unit. The drying unit is used to dry fruits and vegetables. The driving heat source of the heat pump unit 7 comes from the photovoltaic thermal integration system 1. The cold source from the heat pump unit 7 is connected to the cold storage unit and the freezing unit 9 in turn. The fluid working medium after the freezing unit 9 exchanges heat with the juice and the fluid working medium from the drying unit are both connected to the greenhouse planting unit. The freezing unit 9 provides cold energy to exchange heat with fluids such as juice, and the greenhouse planting unit is connected to the outside atmosphere. The greenhouse planting unit is a greenhouse cultivation room 6.

[0027] As an optional solution, in this embodiment, the freezing unit 9 and the drying unit are connected to the buffer tank 5 through pipelines. The buffer tank 5 and the greenhouse planting unit are provided with a temperature sensor 16 and a humidity sensor 17. The set temperature of the greenhouse planting unit is 15°C-25°C.

[0028] As an optional solution, in this embodiment, the buffer tank 5 is connected to the outside atmosphere, and a valve 15 is provided on each of the four pipelines connected to the buffer tank 5 .

[0029] As an optional solution, the power supply unit in this embodiment also includes a backup power supply 11, which is an external power supply; the external power supply can be a national power grid, a generator or other power supply, and when the photovoltaic thermal integration system 1 is short of power (in bad weather or at night), it can supply power to various electrical devices. The photovoltaic thermal integration system 1 is connected to a battery to facilitate the storage of the remaining power and supply power to various electrical devices when needed at night. A heat exchanger is arranged on the photovoltaic thermal integration system 1, and the fluid working medium in the heat exchanger exchanges heat with the photothermal module in the photovoltaic thermal integration system 1. The low-grade heat source coming out of the heat exchanger is connected to the heat pump unit 7. In this embodiment, the low-grade heat source can be hot air or hot water.

[0030] As an optional solution, the heat collection unit 2 in this embodiment is a concentrating solar collector, which includes a concentrator 18, a heat collecting tube 12, a porous heat absorbing material 14 and a fluid medium. The concentrator 18 is used to collect and reflect sunlight onto the heat collecting tube 12. The heat collecting tube 12 is provided with a porous heat absorbing material 14. The fluid medium is a gas or a liquid and is connected to the heat storage tank body 3 through a pipeline. The heat collecting tube 12 is connected to the source of the fluid medium through a fan 13 or a pump body, and the fluid medium is added to the heat collecting tube 12 and the heat storage unit in sequence. In this embodiment, after the sunlight is reflected by the concentrator 18, it is projected onto the surface of the heat collecting tube 12, and the porous heat absorbing material 14 in the heat collecting tube 12 is heated by thermal radiation; then the room temperature air is blown into the heat collecting tube 12 by the fan 13, and heat is exchanged with the porous heat absorbing material 14 to obtain high-temperature air, which then enters the heat storage tank for heat storage. Among them, the large specific surface area characteristics of the porous heat-absorbing material 14 can effectively increase the convective heat exchange between heat transfer fluids such as air and solid materials, improve the heat exchange efficiency, and the obtained high-temperature air can also be directly used for fruit and vegetable processing and greenhouse cultivation; the heat collecting tube 12 can directly receive solar radiation, and a compound parabolic concentrator 18 (CPC) can be added on the heat collecting tube 12 to improve the concentration ratio and the heat collection temperature.

[0031] As an optional solution, the heat storage unit in this embodiment includes a heat storage tank body 3 and a heat storage medium. The heat storage tank body 3 is provided with a heat storage medium for storing heat, and the heat storage medium is a material with high thermal conductivity and high temperature resistance. In this embodiment, the heat storage medium stores heat, and at night or on cloudy days, the heat exchange between the fluid working medium and the heat storage medium can meet the continuous heat demand of the fruit and vegetable drying device and the fruit and vegetable greenhouse cultivation room 6.

[0032] As an optional solution, the heat storage medium in this embodiment includes at least one of ceramsite, rock, sand and stainless steel balls.

[0033] As an optional solution, the drying unit in this embodiment is a drying box 4, and the temperature of the drying box 4 is set to 50°C-150°C. In this embodiment, the heat provided by solar energy is used to achieve the dehydration and drying of the fruit and vegetable, which is energy-saving and environmentally friendly, and can also effectively shorten the drying time and improve the quality of dried fruits and vegetables; the waste heat from the drying unit and the waste heat from the heat pump device can provide continuous heating for the crops in the greenhouse cultivation room 6, maintaining a certain temperature and humidity in the fruit and vegetable greenhouse cultivation room 6.

[0034] As an optional solution, in this embodiment, the cold source from the heat pump unit 7 is liquid, usually water, and the cold storage unit is a phase change cold storage device 8. The phase change cold storage device 8 stores the cold source from the heat pump unit 7 in the form of ice slurry or ice-water mixture, and the phase change cold storage device 8 provides a cold source for the freezing unit 9. In this embodiment, the phase change cold storage device 8 stores the solar photovoltaic electricity in the form of cold energy, and extracts cold energy from the cold storage device at night or on cloudy days to meet the continuous cold demand of the juice freezing device; the freezing unit 9 is a juice rapid cooling device, which uses the supercooled fluid working medium provided by the heat pump unit 7 and the phase change cold storage device 8 to achieve rapid cooling of the juice and continuous supply of renewable energy.

[0035] As an optional solution, in this embodiment, the heat storage unit, drying unit, cold storage unit, freezing unit 9 and greenhouse planting unit can be arranged in parallel or in series in several groups at corresponding positions to achieve the cascade utilization of thermal energy, so that different grades of thermal energy in fruit and vegetable processing and greenhouse cultivation can be reasonably utilized, achieving the effect of energy saving and emission reduction.

[0036] The photovoltaic-thermal integration system 1 of this embodiment utilizes solar energy to collect solar energy through photovoltaic panels to generate electricity, and utilizes the fluid working medium in the heat exchanger to cool the photothermal module to exchange heat, thereby providing the required medium-low temperature driving heat source for the heat pump unit 7, and the photovoltaic module provides electric energy for the heat pump unit 7. The heat pump unit 7 realizes refrigeration through the heat pump unit, and realizes the storage of cold in the phase change cold storage device 8 in the form of phase change cold storage such as ice slurry, thereby providing a continuous cold source for fruit and vegetable processing and greenhouse cultivation room 6. When the solar energy is sufficient, the heat storage unit stores the high-temperature heat source in the heat collection unit 2 in the heat storage medium through the fluid working medium, and the fluid working medium after heat exchange with the heat storage medium enters the fruit and vegetable processing and greenhouse cultivation room 6; when the solar energy irradiation is insufficient, the storage battery and the backup power supply 11 of the photovoltaic-thermal integration system 1 can provide power guarantee for the electrical equipment in the system, and the fluid working medium can directly obtain medium-high temperature fluid working medium after heat exchange with the high-temperature heat storage medium, and obtain low temperature cold source after heat exchange with the cold storage unit, thereby providing a heat source with suitable temperature and humidity for fruit and vegetable processing, rapid cooling of juice and greenhouse cultivation room 6. The system of this embodiment changes the current situation that the fruit and vegetable drying and cooling systems rely on power grid electricity to provide heat and cold sources, and uses solar energy to provide the energy required by the system, effectively reducing the carbon emissions of the system; the solar energy is converted into high-temperature heat source and green electricity through the heat collection unit 2 and the photovoltaic thermal integration system 1, realizing the application of the zero-carbon system in the comprehensive fruit and vegetable utilization system; and then the high-temperature air is sequentially input into the fruit and vegetable drying device, the fruit and vegetable greenhouse cultivation room 6 and other devices, according to the heat and grade required in the fruit and vegetable production process, the energy ladder and efficient utilization are realized.

[0037] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fruit and vegetable processing heat energy comprehensive utilization system using solar energy, characterized by: It includes a power supply unit, a heat collection unit, a heat storage unit, a drying unit, a heat pump unit, a cold storage unit, a freezing unit and a greenhouse planting unit. The power supply unit includes a photovoltaic thermal integration system. The photovoltaic thermal integration system is electrically connected to the heat collection unit, the heat storage unit, the drying unit, the heat pump unit, the cold storage unit and the freezing unit. The heat collection unit can collect heat using solar energy. The fluid working medium of the heat collection unit is connected with the heat storage unit through a pipeline. The heat storage unit can store the heat source transferred from the heat collection unit and can transfer it to the drying unit. The drying unit is used for drying fruits and vegetables. The driving heat source of the heat pump unit comes from the photovoltaic thermal integration system. The cold source coming out of the heat pump unit is connected with the cold storage unit and the freezing unit in sequence. The fluid working medium after heat exchange between the freezing unit and the juice and the fluid working medium coming out of the drying unit are both connected with the greenhouse planting unit. The greenhouse planting unit is connected with the outside atmosphere.

2. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The freezing unit and the drying unit are both connected to a buffer tank through pipelines. A temperature sensor and a humidity sensor are provided in the buffer tank and the greenhouse planting unit. The set temperature of the greenhouse planting unit is 15°C-25°C.

3. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 2, characterized in that: The buffer tank is connected to the outside atmosphere, and a valve is arranged on each of the four pipelines connected to the buffer tank.

4. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The power supply unit also includes a backup power supply, which is an external power supply; the photovoltaic thermal integration system is connected to a battery, and a heat exchanger is provided on the photovoltaic thermal integration system. The fluid in the heat exchanger exchanges heat with the thermal module in the photovoltaic thermal integration system, and the low-grade heat source coming out of the heat exchanger is connected to the heat pump unit.

5. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The heat collection unit is a concentrating solar thermal collector, which includes a concentrator, a heat collection tube, a porous heat absorbing material and a fluid medium. The concentrator is used to concentrate and reflect sunlight onto the heat collection tube. The porous heat absorbing material is arranged in the heat collection tube. The fluid medium is gas or liquid. The heat collection tube is connected to the source of the fluid medium through a fan or a pump body.

6. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The heat storage unit comprises a heat storage tank body and a heat storage medium. The heat storage tank body is provided with a heat storage medium for storing heat. The heat storage medium is a material with high thermal conductivity and high temperature resistance.

7. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 6 is characterized in that: The heat storage medium includes at least one of ceramsite, rock, sand and stainless steel balls.

8. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The drying unit is a drying box, and the temperature of the drying box is set to 50°C-150°C.

9. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The cold source from the heat pump unit is liquid, and the cold storage unit is a phase change cold storage device. The phase change cold storage device stores the cold source from the heat pump unit in the form of ice slurry or ice-water mixture, and the phase change cold storage device provides a cold source for the refrigeration unit.

10. The system for comprehensive utilization of heat energy for fruit and vegetable processing using solar energy according to claim 1, characterized in that: The heat storage unit, the drying unit, the cold storage unit, the freezing unit and the greenhouse planting unit can be arranged in parallel or in series in a plurality of groups at corresponding positions.

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