WO2019192314A1

WO2019192314A1 - Machine for on-site rapid pre-cooling of fruit

Info

Publication number: WO2019192314A1
Application number: PCT/CN2019/078613
Authority: WO
Inventors: 郜海燕; 陈孝柳; 陈杭君; 费明华; 周拥军; 房祥军
Original assignee: 浙江省农业科学院; 嘉兴市机械研究所有限责任公司
Priority date: 2017-08-12
Filing date: 2019-03-19
Publication date: 2019-10-10
Also published as: CN108684812A

Abstract

A machine for on-site rapid pre-cooling of a fruit, the machine comprising a container body, a refrigeration device, a dehumidifier device, a control device, and a sterilization device. The container body is internally provided with a pre-cooling chamber and a refrigeration chamber. The refrigeration device comprises a compressor, a condenser, a liquid storage barrel, and an evaporator sequentially connected by a pipeline. The compressor, the condenser, and the liquid storage barrel are provided within the refrigeration chamber. The evaporator is provided within the pre-cooling chamber. The evaporator comprises a finned evaporation tube and a fan. The dehumidifier device comprises an electric heater and a water draining valve. The electric heater is provided at one side of the finned evaporation tube. The water draining valve is at a bottom portion of the pre-cooling chamber. The sterilization device is provided within the pre-cooling chamber.

Description

Fruit on-site rapid pre-cooler

Technical field

The invention relates to the technical field of fruit pre-cooling equipment, in particular to a rapid pre-cooling machine for fruit.

Background technique

Fruits carry a lot of field heat after harvest, which promotes their breathing intensity. The mechanical injury during harvesting will further enhance the respiration, release a large amount of respiratory heat, and cause the fruit temperature to rise, thus accelerating the decline of quality and decay and aging. Therefore, it is the key to maintaining its freshness and nutritional value after the fruit is quickly cooled to low temperature after harvesting and then stored or circulated. At present, developed countries such as Europe, the United States and Japan have taken pre-cooling of fruits and vegetables as an indispensable process. Fruits such as bayberry and blueberry are harvested in high temperature and rainy season. By timely pre-cooling, respiration can be inhibited, nutrient consumption can be reduced, and shelf life can be extended. Pre-cooling is an important step in post-harvest commercialization. Studies have shown that the shorter the interval between the post-harvest and the pre-cooling of the fruits such as bayberry and blueberry, the better the quality is maintained. However, at present, there is no light in-situ pre-cooling equipment available on the market. After harvesting, it usually takes 3-5 hours to be transported to the cold storage to pre-cool, which seriously affects the preservation effect. Therefore, it is essential to research and develop convenient and rapid pre-cooling equipment suitable for the production of fruit such as bayberry and blueberry.

Summary of the invention

In order to solve the above problems in the use of pre-cooling and preservation of fruits such as bayberry and blueberry, the present invention proposes a fruit-based rapid pre-cooling machine capable of achieving rapid cooling, bacteriostatic dehumidification and transport to the field.

In order to achieve the above object, the present invention provides a berry on-site rapid pre-cooling machine, which comprises a box body, a refrigerating device, a dehumidifying device, a control device and a sterilizing device, and a pre-cooling chamber and a refrigerating chamber are provided in the box body. The refrigerating device comprises a compressor, a condenser, a liquid storage tank and an evaporator which are sequentially connected through a pipeline, the compressor, the condenser and the liquid storage cylinder are arranged in the refrigerating chamber, the evaporator is arranged in the pre-cooling chamber, and the evaporator comprises the evaporating fin The tube tube and the fan, the dehumidifying device includes an electric heater and a drain valve, the electric heater is disposed on one side of the evaporating fin tube, the drain valve is at the bottom of the pre-cooling chamber, and the sterilizing device is disposed in the pre-cooling chamber.

The berry on-site rapid pre-cooling machine provided by the invention has the advantages of fast cooling speed, dehumidification and sterilization function, can effectively maintain the post-harvest quality of the berry, and the whole machine is light in weight and convenient for handling in the field. The dehumidification device adopts the refrigeration principle, and is completed by the electric heating frost and the automatic drainage by the refrigeration system of the pre-cooler. The sterilizing device is disposed at the bottom of the pre-cooling chamber and may be a plasma generator or an ozone sterilizer. The sterilizer is a separate component that can be selected for the berry variety.

Further, the condenser is an air-cooled condenser having a condensation finned tube, R=60nvη _v (i ₁ -i ₂ )/v ₁ , Q _c =60nvη _v (i ₃ -i ₄ )/v ₁ , Q ₀ = a ₀ F ₀ Δt ₀ , Q _k = a _k F _k Δt _k , satisfying Q ₀ > R, Q _k > Q _c , where R is the compressor refrigeration capacity of the compressor, and Qc is the condensation The condenser of the device emits heat, Q0 is the evaporator heat exchange amount of the evaporator, Qk is the condenser heat exchange amount of the condenser, n is the compressor speed, and v is the piston moving volume of the compressor, η _v For compressor volumetric efficiency, i ₁ is the enthalpy of the evaporator outlet refrigerant, i ₂ is the enthalpy of the evaporator inlet refrigerant, i ₃ is the enthalpy of the final refrigerant, and i ₄ is the condenser outlet refrigerant 焓, v ₁ is the specific volume of refrigerant in the suction port of the compressor, a ₀ is the surface heat transfer coefficient of the heat dissipation area of the evaporating fin tube, F ₀ is the heat dissipation area of the evaporating fin tube, and Δt ₀ is the heat exchange temperature difference of the evaporator. a _k is the surface heat transfer coefficient of the heat dissipation area of the condensation fin tube, F _k is the heat dissipation area of the condensation fin tube, and Δt _k is the heat exchange temperature difference of the condenser. The invention optimizes the matching between the various parts of the refrigeration device, and the cooling speed is fast, and the rapid pre-cooling is achieved from room temperature 30 ° C to 0 ° C for 10 minutes.

DRAWINGS

Figure 1 is a schematic structural view of the present invention;

Figure 2 is a partial cross-sectional view showing the present invention;

Figure 3 is a schematic view showing the structure of the refrigeration apparatus.

The invention will be further described in detail below with reference to the accompanying drawings.

detailed description

Referring to Fig. 1 and Fig. 2, the box 1 of the fruit on-site rapid pre-cooler is a square flat wall structure, which is filled with a high-density thermal insulation material, including an inner wall, an outer wall and an insulating material sandwiched between the outer walls of the inner wall, the inner wall and The outer wall is made of stainless steel plate and the insulation material is polystyrene foam (EPS). The insulation performance is good and the cabinet is light in weight. A pre-cooling chamber 11 and a refrigerating chamber 12 are provided in the casing 1. There are 4 wheels at the bottom of the box 1. The whole machine weighs less than 100 kg, which is convenient for handling in the field.

Referring to FIG. 3, the refrigerating apparatus includes a compressor 21, a condenser 22, a liquid storage tank 23, and an evaporator 24 which are sequentially connected through a pipeline, and the compressor 21, the condenser 22, and the liquid storage cylinder 23 are disposed in the refrigerating chamber 12, and are cooled. There is enough space in the chamber 12 for heat dissipation. The evaporator 24 is disposed in the pre-cooling chamber 11.

The condenser 22 is an air-cooled condenser having a condensing finned tube 221 and a structural type of a forced-venting finned tube. The evaporator 24 is selected from a cooling fan, and includes a evaporation fin tube 241 and a fan 242. The structure of the evaporation fin tube 241 is a forced ventilation type fin tube, and the fan 242 is a double fan, and the fan is used to forcibly exchange heat.

The present invention is relatively important for the matching between the various parts of the refrigeration device because the refrigeration speed is relatively high. The compressor refrigeration capacity of the compressor 21 is R, the condenser heat release amount of the condenser 22 is Qc, the condenser heat exchange amount of the condenser 22 is Qk, and the evaporator heat exchange amount of the evaporator 24 is Q0. R=60nvη _v (i ₁ -i ₂ )/v ₁ , Q _c =60nvη _v (i ₃ -i ₄ )/v ₁ , Q ₀ =a ₀ F ₀ Δt ₀ ,Q _k =a _k F _k Δt _k , satisfying Q ₀ >R, Q _k >Q _c . Where n is the compressor speed, v is the piston's piston moving volume, η _v is the compressor volumetric efficiency, i ₁ is the enthalpy of the evaporator outlet refrigerant, i ₂ is the evaporator inlet refrigerant i, i ₃ is the compression At the end of the refrigerant enthalpy, i ₄ is the enthalpy of the refrigerant at the outlet of the condenser, v ₁ is the specific volume of the refrigerant at the suction port of the compressor, and a ₀ is the surface heat transfer coefficient of the heat dissipating area of the evaporating fin tube, and F ₀ is The heat dissipation area of the evaporation finned tube, Δt ₀ is the heat exchange temperature difference of the evaporator, a _k is the surface heat transfer coefficient of the heat dissipation area of the condensation fin tube, F _k is the heat dissipation area of the condensation fin tube, and Δt _k is the condensation The heat exchange temperature difference of the device.

In the present embodiment, a Danfoss 5/8HP fully enclosed compressor is selected as the cooling source, the piston moving volume of the compressor is v=18 cm ³ /r, and the compressor volumetric efficiency is η _v =0.75. The refrigeration unit uses R22 refrigerant, set the evaporation temperature t ₀ =-10 ° C, the compressor suction port temperature t ₁ =0 ° C, the condensation temperature t _k =36 ° C, check the thermal properties of the refrigerant R22 to obtain: t ₀ = -10 ° C, P ₀ = 0.356 MPa, i ₁ = 621.6 kj / kg, i ₂ = 407.2 kj / kg, v ₁ = 69.51 × 10 ^-3 m ³ / kg, t _k = 36 ° C, P _k = 1.40 MPa, i ₃ = 636.5 kj/kg, i ₄ = 418.7 kj/kg. When the compressor speed is n=2880r/min,

R=60nvη _v (i ₁ -i ₂ )/v ₁ =7195.3kj/h=2000w,

Q _c = 60 nvη _v (i _{3 -} i ₄ ) / v ₁ = 7309.4 kj / h = 2030.3w.

The evaporator is a cooling fan DE-1.4/5.0, and its heat dissipation area of the finned tube is F ₀ =5.0m ² , a ₀ =75W/m ² .k, when Δt ₀ =10, Q ₀ =a ₀ F ₀ Δt ₀ = 3750W>R.

The condenser is air-cooled condenser FNH-2.0/7.0, its heat dissipation area of finned fin tube is F _k =7.0m ² , a ₀ =75W/m ² .k, when Δt _k =6, Q _k =a _k F _k Δt _k =3150W>Q _c .

The dehumidifying device employs an electric heating cream, automatic drainage, and includes an electric heater and a drain valve 3, the electric heater is disposed on one side of the evaporating fin tube, and the drain valve 3 is at the bottom of the pre-cooling chamber 11. The working process is carried out according to the set program, the refrigeration device is started, the surface of the evaporator 24 is frosted, the electric heater is activated, and after the frost on the surface of the evaporator 24 is quickly dissolved, the drain valve 3 is automatically opened for drainage. The dehumidification device adopts the refrigeration principle, and is completed by the electric heating frost and the automatic drainage by the refrigeration system of the pre-cooler.

The sterilizing device 4 is disposed at the bottom of the pre-cooling chamber 11, and may be a plasma generator or an ozone sterilizer. The sterilizing device 4 is a separate component and can be selected according to the berry variety.

The control system controls the refrigeration device, the dehumidification device and the sterilization device, and is controlled by a PLC program. The operation panel is a color touch screen, and the operation is convenient and intuitive. The control system can control the cooling and defrost temperatures manually or automatically. The manual cooling is started or stopped by the touch screen, and the cooling temperature and the defrosting temperature can be displayed in real time on the touch screen. When the motor is automatic, the cooling temperature and its positive and negative deviation, cooling time, defrost temperature, and defrosting time are set by the touch screen, and then the automatic pre-cooling is turned on.

The invention has the advantages of fast cooling speed, dehumidification and sterilization function, and can effectively maintain the post-harvest quality of the berries, and the whole machine is light in weight and convenient for handling in the field.

Claims

The invention relates to a fruit on-site rapid pre-cooling machine, which comprises a box body, a refrigerating device, a dehumidifying device, a control device and a sterilizing device, wherein a pre-cooling chamber and a refrigerating chamber are arranged in the box body, and the refrigerating device comprises a serial connection through a pipeline. a compressor, a condenser, a liquid storage tank and an evaporator, a compressor, a condenser and a liquid storage cylinder are disposed in the refrigeration chamber, the evaporator is disposed in the pre-cooling chamber, the evaporator includes a evaporation fin tube and a fan, and the dehumidification device includes electricity A heater and a drain valve are disposed on one side of the evaporating fin tube, a drain valve is at a bottom of the pre-cooling chamber, and a sterilizing device is disposed in the pre-cooling chamber.
The fruit in-situ rapid pre-cooler according to claim 1, wherein the condenser is an air-cooled condenser having a condensation finned tube, R = 60nvη v (i 1 - i 2 ) / v 1 , Q c =60nvη v (i 3 -i 4 )/v 1 , Q 0 =a 0 F 0 Δt 0 ,Q k =a k F k Δt k , satisfying Q 0 >R, Q k >Q c , where R For the compressor refrigeration capacity of the compressor, Q c is the condenser heat release of the condenser, Q 0 is the evaporator heat exchange amount of the evaporator, and Q k is the condenser heat exchange of the condenser Quantity, n is the compressor speed, v is the piston moving volume of the compressor, η v is the compressor volumetric efficiency, i 1 is the enthalpy of the evaporator outlet refrigerant, i 2 is the enthalpy of the evaporator inlet refrigerant, i 3 is Compressing the enthalpy of the refrigerant, i 4 is the enthalpy of the refrigerant at the outlet of the condenser, v 1 is the specific volume of the refrigerant at the suction port of the compressor, and a 0 is the surface heat transfer coefficient of the heat dissipating area of the evaporating fin tube, F 0 finned tube evaporation cooling area, Δt 0 is the temperature difference of the evaporator, a k is a finned tube for condensing heat transfer coefficient of the heat dissipation surface area meter, F k is the condensed cooling area finned tube, Δt k is The temperature difference in the condenser.
The fruit in-situ rapid pre-cooler according to claim 2, wherein the sterilizing device is a plasma generator or an ozone sterilizer.
The fruit in-situ rapid pre-cooler according to claim 3, wherein the casing comprises an inner wall, an outer wall and an insulating material sandwiched between the outer walls of the inner wall, and the bottom of the casing is provided with a plurality of wheels.