Energy-saving tea leaf heat pump drying device and drying method

Abstract

The invention discloses an energy-saving tea leaf heat pump drying device and method, a first circulating hot air unit receives heat energy of external air to generate a first drying medium, the first drying medium is low-pressure high-temperature gas, and after the first drying medium is input into a drying unit, tea leaves in the drying unit are dried; the first drying medium can evaporate a large amount of moisture in the tea leaf drying process, so that the moisture carried by the first drying medium, namely moisture enthalpy-increased gas, is input into the second circulating hot air unit through the ventilation unit and is converted into the second drying medium, and the second drying medium is dry low-pressure high-temperature gas; through mutual fusion of the second drying medium and the first drying medium, tea leaves and moisture in the drying unit are circularly dried, and then the technical problems that when an existing air energy heat pump dryer discharges moisture, the temperature fluctuation of a drying room is large, and the drying quality is affected are solved. And the second circulating hot air unit is pollution-free and low in energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of energy-saving drying, and in particular to an energy-saving tea heat pump drying device and a drying method. Background Art

[0002] Heat pump drying is an energy-efficient drying technology. It achieves heat transfer through a system consisting of an evaporator, compressor, condenser and expansion valve. It can be applied to a variety of materials, such as tea, fruits and vegetables, etc. It has good drying effects and is relatively environmentally friendly. It is a high-quality choice in the drying field.

[0003] At present, the mainstream tea drying system on the market mainly adopts air-energy heat pump tea drying machine, which can accurately control the drying temperature and humidity, so that the tea leaves can be dried evenly in a suitable temperature and humidity environment, which helps to improve the quality of tea leaves; it adopts an intelligent control system, which is easy to operate and does not require a dedicated person to watch for a long time. However, since the air-energy heat pump dryer has a large temperature fluctuation in the drying room when dehumidifying, which affects the drying quality, it is urgent to design an energy-saving tea heat pump drying device that can quickly dehumidify to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide an energy-saving tea heat pump drying device and a drying method to solve the problems described in the background technology.

[0005] The technical solution of the present invention is achieved in this way:

[0006] The present invention provides an energy-saving tea heat pump drying device, comprising a first circulating hot air unit, which is used to receive heat energy from external air and convert it into a first drying medium. The first drying medium is input into the drying unit through a circulation pipeline and circulates in the drying unit. The first drying medium is output through a ventilation unit provided in the drying unit.

[0007] The ventilation unit is connected to a second circulating hot air unit, which receives the first drying medium and converts it into a second drying medium. After the second drying medium is input into the drying unit, it is re-input into the second circulating hot air unit through the ventilation unit.

[0008] A further technical solution is that the first circulating hot air unit includes an evaporator, a first compressor, a condenser, an expansion valve and a hot fan. The evaporator has a built-in liquid refrigerant, and the first gaseous refrigerant is obtained by absorbing the heat energy of the external air through the evaporator. The first gaseous refrigerant is input into the first compressor through the circulation pipe to obtain the second gaseous refrigerant. The second gaseous refrigerant is input into the condenser and converted into the first drying medium and the liquid refrigerant. The first drying medium is input into the drying unit through the hot fan. The liquid refrigerant is throttled by the expansion valve and then input into the evaporator through the circulation pipe to reabsorb the heat energy of the external air.

[0009] A further technical solution is that the drying unit includes a drying chamber and a drying rack arranged in the drying chamber, the drying chamber is connected to the condenser output end, the hot fan inputs the first drying medium into the drying chamber through the condenser output end, and circulates in the drying chamber to dry the tea leaves on the drying rack.

[0010] A further technical solution is that the first drying medium is output to the outside of the drying chamber through the ventilation unit, wherein the ventilation unit includes a first ventilator and a second ventilator, the bottom of the first ventilator extends from the top surface of the drying chamber and is connected to the inside of the drying chamber, the bottom of the second ventilator extends from the side of the drying chamber and is connected to the inside of the drying chamber, the first ventilator and the second ventilator are respectively located above the top and on the side of the drying rack, and the first ventilator and the second ventilator are connected to the second circulating hot air unit through a circulation duct.

[0011] A further technical solution is that the second circulating hot air unit includes a second compressor, a dehumidifier and an expander, the output ends of the first ventilator and the second ventilator are connected to the second compressor through a circulation pipe, the second compressor compresses the first drying medium and obtains a first high-temperature and high-pressure gas, the output end of the second compressor is connected to the dehumidifier, the dehumidifier performs gas-liquid separation on the first high-temperature and high-pressure gas to obtain a second high-temperature and high-pressure gas, the output end of the dehumidifier is connected to the expander, the second high-temperature and high-pressure gas is input into the expander to obtain the second drying medium, and the second drying medium is input into the drying chamber through the circulation pipe.

[0012] A further technical solution is that the second compressor is provided with a first drive shaft, the expander is provided with a second drive shaft, the first drive shaft is connected to a first bevel gear, the second drive shaft is provided with a second bevel gear, and the first bevel gear is meshed with the second bevel gear.

[0013] A further technical solution is that a plurality of drying tubes are arranged in the drying chamber, the drying tubes are passed through the bottom of the drying rack, the output end of the expander is connected to the input end of the drying tube through another flow pipe, the output end of the drying tube is connected to the first input end of the heat exchanger arranged outside the drying chamber, the second drying medium enters the flow pipe of the second compressor input end through the first output end of the heat exchanger, cold liquid circulates between the second input end and the second output end of the heat exchanger, and a first air stop valve is provided between the expander and the drying tube.

[0014] A further technical solution is that the output end of the expander is connected to the input end of the evaporator through a flow pipe, and a second air stop valve is provided between the expander and the evaporator.

[0015] A further technical solution is that the dehumidifier is a water-gas separator.

[0016] Another aspect of the present invention provides an energy-saving tea heat pump drying method, comprising the following steps:

[0017] Step S1, the first circulating hot air unit receives external air heat energy to generate a first drying medium;

[0018] Step S2, the first drying medium flows from the output end of the first circulating hot air unit into the drying unit to dry the tea leaves;

[0019] Step S3, the first drying medium is input into the second circulating hot air unit through the ventilation unit;

[0020] Step S4: the second circulating hot air unit receives the first drying medium and generates a second drying medium, and the second drying medium flows into the drying unit for dehumidification.

[0021] The beneficial effects of the present invention are:

[0022] The present invention receives heat energy from external air through a first circulating hot air unit to generate a first drying medium, which is a low-pressure and high-temperature gas. After the first drying medium is input into the drying unit, the tea leaves in the drying unit are dried. The first drying medium evaporates a large amount of moisture during the drying process of the tea leaves. Therefore, the moisture carried by the first drying medium, i.e., the humidified enthalpy-increasing gas, is input into the second circulating hot air unit through the ventilation unit and converted into a second drying medium. The second drying medium is a dry low-pressure and high-temperature gas. The second drying medium is fused with the first drying medium to circulate and dry the tea leaves and moisture in the drying unit, thereby solving the technical problem that the existing air energy heat pump dryer has a large temperature fluctuation in the drying room during dehumidification, which affects the drying quality. The use of the second circulating hot air unit is pollution-free and has low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the method flow of the present invention.

[0025] In the figure, 1, evaporator; 2, first compressor; 3, condenser; 4, expansion valve; 5, hot fan; 6, drying chamber; 7, drying rack; 8, first ventilator; 9, second ventilator; 10, second compressor; 11, dehumidifier; 12, expander; 13, first drive shaft; 14, second drive shaft; 15, first bevel gear; 16, second bevel gear; 17, drying tube; 18, first stop valve; 19, second stop valve; 20, heat exchanger. DETAILED DESCRIPTION

[0026] In order to better understand the technical content of the present invention, specific embodiments are provided below, and the present invention is further described in conjunction with the accompanying drawings.

[0027] See also Figure 1 to Figure 2 On the one hand, the present invention provides an energy-saving tea heat pump drying device, comprising a first circulating hot air unit, which is used to receive external air heat energy and convert it into a first drying medium. The first drying medium is input into the drying unit through a circulation pipe and circulates in the drying unit. The first drying medium is output through a ventilation unit provided in the drying unit; the ventilation unit is connected to a second circulating hot air unit, which receives the first drying medium and converts it into a second drying medium. After the second drying medium is input into the drying unit, it is re-input into the second circulating hot air unit through the ventilation unit.

[0028] It should be noted that both the first drying medium and the second drying medium are high-temperature low-pressure gases, and when the first drying medium dries the tea leaves in the drying unit, it carries the evaporated moisture of the tea leaves into the ventilation unit. When the second drying medium enters the drying unit, it can also dry the tea leaves and accelerate the dehumidification process.

[0029] Specifically, the first circulating hot air unit receives the heat energy of the external air to generate the first drying medium, which is a low-pressure and high-temperature gas. After the first drying medium is input into the drying unit, the tea leaves in the drying unit are dried. The first drying medium will evaporate a large amount of moisture during the drying process of the tea leaves. Therefore, the moisture carried by the first drying medium, that is, the humidified enthalpy-increasing gas, is input into the second circulating hot air unit through the ventilation unit and converted into the second drying medium. The second drying medium is a dry low-pressure and high-temperature gas. The second drying medium and the first drying medium are mutually integrated to circulate and dry the tea leaves and moisture in the drying unit, thereby solving the technical problem that the existing air energy heat pump dryer has a large temperature fluctuation in the drying room during dehumidification, which affects the drying quality. And the use of the second circulating hot air unit is pollution-free and low in energy consumption.

[0030] In this embodiment, the first circulating hot air unit includes an evaporator 1, a first compressor 2, a condenser 3, an expansion valve 4 and a hot fan 5. The evaporator 1 has a built-in liquid refrigerant. The evaporator 1 absorbs the heat energy of the external air to obtain a first gaseous refrigerant. The first gaseous refrigerant is input into the first compressor 2 through the circulation pipe to obtain a second gaseous refrigerant. The second gaseous refrigerant is input into the condenser 3 and converted into the first drying medium and the liquid refrigerant. The first drying medium is input into the drying unit through the hot fan 5. The liquid refrigerant is throttled by the expansion valve 4 and then input into the evaporator 1 through the circulation pipe to reabsorb the heat energy of the external air.

[0031] The refrigerant of the evaporator 1 is R134a type refrigerant. When the evaporator 1 is started, the refrigerant absorbs the heat energy of the external air. Through the continuous heat absorption, the refrigerant becomes the first gaseous refrigerant, that is, a low-pressure and low-temperature gas, and is input into the first compressor 2 through the circulation pipeline to compress the first gaseous refrigerant to generate the second gaseous refrigerant, that is, a high-temperature and high-pressure gas. The second gaseous refrigerant enters the condenser 3 through the circulation pipeline. The condenser 3 performs heat exchange with the heat energy of the second gaseous refrigerant to generate the first drying medium, and the first drying medium is input into the drying unit through the hot fan 5 to dry the tea leaves. While the condenser 3 performs heat exchange with the second gaseous refrigerant, the second gaseous refrigerant cools itself and converts into a liquid state, and under the pressure release of the expansion valve 4, it flows back into the evaporator 1 through the circulation pipeline in a liquid state to start the next cycle, thereby improving the energy saving effect.

[0032] Furthermore, the drying unit includes a drying chamber 6 and a drying rack 7 arranged in the drying chamber 6, the drying chamber 6 is connected to the output end of the condenser 3, the hot fan 5 inputs the first drying medium into the drying chamber 6 through the output end of the condenser 3, and circulates in the drying chamber 6 to dry the tea leaves on the drying rack 7.

[0033] The drying chamber 6 is a closed drying chamber 6. Tea leaves are placed on a drying rack 7 in the drying chamber 6. The first drying medium circulates in the closed drying chamber 6 to dry the tea leaves on the drying rack 7. The first drying medium is driven to circulate in the drying chamber 6 by the hot fan 5 to increase the circulation rate of the first drying medium, thereby improving the tea drying effect.

[0034] In a preferred embodiment, the first drying medium is output to the outside of the drying chamber 6 through the ventilation unit, wherein the ventilation unit includes a first ventilator 8 and a second ventilator 9, the bottom of the first ventilator 8 extends from the top surface of the drying chamber 6 and is connected to the drying chamber 6, the bottom of the second ventilator 9 extends from the side of the drying chamber 6 and is connected to the drying chamber 6, the first ventilator 8 and the second ventilator 9 are respectively located above the top and on the side of the drying rack 7, and the first ventilator 8 and the second ventilator 9 are connected to the second circulating hot air unit through a circulation duct.

[0035] During the drying process of the first drying medium, the moisture evaporated from the tea leaves cannot be quickly dehumidified, and the dehumidification efficiency is low when drying the tea leaves. Therefore, a first ventilator 8 and a second ventilator 9 are respectively arranged on the top and side of the drying unit. When the first drying medium circulates in the drying chamber 6, the moisture evaporated from the tea leaves is brought into the circulation duct through the first ventilator 8 and the second ventilator 9 and enters the second circulating hot air unit from the circulation duct. The first ventilator 8 and the second ventilator 9 can increase the output of the first drying medium and quickly input the first drying medium into the second circulating hot air unit.

[0036] In this embodiment, the second circulating hot air unit includes a second compressor 10, a dehumidifier 11 and an expander 12. The output ends of the first ventilator 8 and the second ventilator 9 are both connected to the second compressor 10 through a circulation pipeline. The second compressor 10 compresses the first drying medium to obtain a first high-temperature and high-pressure gas. The output end of the second compressor 10 is connected to the dehumidifier 11. The dehumidifier 11 performs gas-liquid separation on the first high-temperature and high-pressure gas to obtain a second high-temperature and high-pressure gas. The output end of the dehumidifier 11 is connected to the expander 12. The second high-temperature and high-pressure gas is input into the expander 12 to obtain the second drying medium. The second drying medium is input into the drying chamber 6 through the circulation pipeline.

[0037] When the first drying medium enters the second compressor 10, the first drying medium is compressed by the second compressor 10 to generate a first high-temperature and high-pressure gas, which carries moisture. After the first high-temperature and high-pressure gas enters the dehumidifier 11, the dehumidifier 11 separates the moisture carried by the first high-temperature and high-pressure gas to obtain a second high-temperature and high-pressure gas, that is, a dry high-temperature and high-pressure gas. The second high-temperature and high-pressure gas is input into the expander 12, and the second high-temperature and high-pressure gas is converted into a second drying medium, that is, a low-pressure and high-temperature gas, by the expander 12. The second drying medium is input into the drying chamber 6, and the second drying medium quickly eliminates the moisture evaporated from the tea leaves to ensure the drying quality of the tea leaves.

[0038] The present invention uses the second drying medium output by the second circulating hot air unit to quickly eliminate moisture evaporated from the tea leaves, and uses the first drying medium as an air source for input, without the need for refrigerant assistance, thereby reducing the degree of air damage, improving environmental protection effects, and having low energy consumption.

[0039] In a preferred embodiment, the second compressor 10 is provided with a first drive shaft 13, the expander 12 is provided with a second drive shaft 14, the first drive shaft 13 is connected with a first bevel gear 15, the second drive shaft 14 is provided with a second bevel gear 16, and the first bevel gear 15 is meshed with the second bevel gear 16.

[0040] The expander 12 is a turbine expander 12. When the second drying medium enters the expander 12, under the high-pressure state of the second drying medium, the internal energy of the expander 12 is converted into mechanical energy, driving the second drive shaft 14 and the second bevel gear 16 to rotate, and the first bevel gear 15 and the first rotating shaft are driven to rotate through the second bevel gear 16. The first rotating shaft starts the second compressor 10 to compress the first drying medium through its own mechanical energy, so that the first compressor 2 reduces the power source input and reduces energy consumption.

[0041] In a preferred embodiment, a plurality of drying tubes 17 are installed in the drying chamber 6, and the drying tubes 17 are installed at the bottom of the drying rack 7. The output end of the expander 12 is connected to the input end of the drying tube 17 through another circulation pipe. The output end of the drying tube 17 is connected to the first input end of the heat exchanger 20 arranged outside the drying chamber 6. The second drying medium enters the circulation pipe of the input end of the second compressor 10 through the first output end of the heat exchanger 20. Cold liquid circulates between the second input end and the second output end of the heat exchanger 20. A first air stop valve 18 is provided between the expander 12 and the drying tube 17.

[0042] The first air stop valve 18 is opened, and the first air stop valve 18 cuts off the flow pipeline of the expander 12 input into the drying chamber 6, and the second drying medium is input into the drying tube 17. When the second drying medium is in a high temperature state, the drying tube 17 generates a high temperature, and when multiple drying tubes 17 are set up at the bottom of the drying rack 7, the bottom of the tea leaves are dried to improve the overall drying efficiency of the tea leaves. When the second drying medium in the drying tube 17 is output through the output end of the drying tube 17, the heat exchanger 20 uses a water pump to circulate cold water, and reduces the temperature of the second drying medium by heat exchange, preventing the high-temperature gas from being input into the second compressor 10 and damaging its mechanical energy.

[0043] The first air check valve 18 of this embodiment is an electric two-way switching valve, which is convenient for switching the flow pipeline between the expander 12 input drying chamber 6 and the drying pipe 17.

[0044] In a preferred implementation, the output end of the expander 12 is connected to the input end of the evaporator 1 through a flow pipe, and a second air stop valve 19 is provided between the expander 12 and the evaporator 1 .

[0045] It should be noted that the second air stop valve 19 is a conventional air stop valve.

[0046] In one example, when drying tea leaves in a low-temperature environment, the expander 12 inputs the second drying medium into the drying chamber 6, and at the same time, opens the second air check valve 19 to input the second drying medium into the evaporator 1. The evaporator 1 receives the second drying medium to improve the gas conversion efficiency of the refrigerant, so that the evaporator 1 avoids using a large amount of energy to convert the refrigerant into gas in a low-temperature environment, thereby improving the energy saving effect.

[0047] Preferably, the dehumidifier 11 is a moisture separator, which converts the moisture carried by the second drying medium into water and removes it from the moisture separator, thereby improving the dryness of the second drying medium.

[0048] Another aspect of the present invention provides an energy-saving tea heat pump drying method, comprising the following steps:

[0049] Step S1, the first circulating hot air unit receives external air heat energy to generate a first drying medium;

[0050] Step S2, the first drying medium flows from the output end of the first circulating hot air unit into the drying unit to dry the tea leaves;

[0051] Step S3, the first drying medium is input into the second circulating hot air unit through the ventilation unit;

[0052] Step S4: the second circulating hot air unit receives the first drying medium and generates a second drying medium, and the second drying medium flows into the drying unit for dehumidification.

[0053] It should be noted that the principle of this step is consistent with the principle of the device and will not be repeated here.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy-saving tea heat pump drying device, characterized in that: It includes a first circulating hot air unit, which is used to receive heat energy from external air and convert it into a first drying medium. The first drying medium is input into the drying unit through a circulation pipe and circulates in the drying unit. The first drying medium is output through a ventilation unit provided in the drying unit. The ventilation unit is connected to a second circulating hot air unit, which receives the first drying medium and converts it into a second drying medium. After the second drying medium is input into the drying unit, it is re-input into the second circulating hot air unit through the ventilation unit.

2. The energy-saving tea heat pump drying device according to claim 1, characterized in that: The first circulating hot air unit includes an evaporator, a first compressor, a condenser, an expansion valve and a hot fan. The evaporator has a built-in liquid refrigerant, and the first gaseous refrigerant is obtained by absorbing the heat energy of the external air through the evaporator. The first gaseous refrigerant is input into the first compressor through the circulation pipe to obtain the second gaseous refrigerant. The second gaseous refrigerant is input into the condenser and converted into the first drying medium and the liquid refrigerant. The first drying medium is input into the drying unit through the hot fan. The liquid refrigerant is throttled by the expansion valve and then input into the evaporator through the circulation pipe to reabsorb the heat energy of the external air.

3. The energy-saving tea heat pump drying device according to claim 2, characterized in that: The drying unit includes a drying chamber and a drying rack arranged in the drying chamber. The drying chamber is connected to the condenser output end. The hot fan inputs the first drying medium into the drying chamber through the condenser output end, and circulates in the drying chamber to dry the tea leaves on the drying rack.

4. The energy-saving tea heat pump drying device according to claim 3, characterized in that: The first drying medium is output to the outside of the drying chamber through the ventilation unit, wherein the ventilation unit includes a first ventilator and a second ventilator, the bottom of the first ventilator extends from the top surface of the drying chamber and is connected to the inside of the drying chamber, the bottom of the second ventilator extends from the side of the drying chamber and is connected to the inside of the drying chamber, the first ventilator and the second ventilator are respectively located above the top and on the side of the drying rack, and the first ventilator and the second ventilator are connected to the second circulating hot air unit through a circulation duct.

5. The energy-saving tea heat pump drying device according to claim 4, characterized in that: The second circulating hot air unit includes a second compressor, a dehumidifier and an expander. The output ends of the first ventilator and the second ventilator are both connected to the second compressor through a circulation pipeline. The second compressor compresses the first drying medium to obtain a first high-temperature and high-pressure gas. The output end of the second compressor is connected to the dehumidifier. The dehumidifier separates the first high-temperature and high-pressure gas into gas and liquid to obtain a second high-temperature and high-pressure gas. The output end of the dehumidifier is connected to the expander. The second high-temperature and high-pressure gas is input into the expander to obtain the second drying medium. The second drying medium is input into the drying chamber through the circulation pipeline.

6. The energy-saving tea heat pump drying device according to claim 5, characterized in that: The second compressor is provided with a first drive shaft, the expander is provided with a second drive shaft, the first drive shaft is connected with a first bevel gear, the second drive is provided with a second bevel gear, and the first bevel gear is meshed with the second bevel gear.

7. The energy-saving tea heat pump drying device according to claim 5, characterized in that: A plurality of drying tubes are arranged in the drying chamber, and the drying tubes are arranged at the bottom of the drying rack. The output end of the expander is connected to the input end of the drying tube through another circulation pipe, and the output end of the drying tube is connected to the first input end of the heat exchanger arranged outside the drying chamber. The second drying medium enters the circulation pipe of the input end of the second compressor through the first output end of the heat exchanger. Cold liquid circulates between the second input end and the second output end of the heat exchanger, and a first air stop valve is arranged between the expander and the drying tube.

8. The energy-saving tea heat pump drying device according to claim 5, characterized in that: The output end of the expander is connected to the input end of the evaporator through a flow pipeline, and a second air stop valve is provided between the expander and the evaporator.

9. The energy-saving tea heat pump drying device according to claim 5, characterized in that: The dehumidifier is a water-gas separator.

10. A drying method of an energy-saving tea heat pump drying device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, the first circulating hot air unit receives external air heat energy to generate a first drying medium; Step S2, the first drying medium flows from the output end of the first circulating hot air unit into the drying unit to dry the tea leaves; Step S3, the first drying medium is input into the second circulating hot air unit through the ventilation unit; Step S4: the second circulating hot air unit receives the first drying medium and generates a second drying medium, and the second drying medium flows into the drying unit for dehumidification.

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