Liquid nitrogen refrigeration system and method for fishing boat

Abstract

The invention discloses a liquid nitrogen refrigeration system and method for a fishing boat. The system comprises a refrigerating chamber, a liquid nitrogen dewar flask, a liquid nitrogen conveying pipeline, a liquid nitrogen spraying pipeline, a low-temperature electric valve, a controller, a touch display screen and a temperature sensor; the method comprises the following steps that a target temperature of the refrigerating chamber is input, and a starting temperature of the refrigerating chamber is collected; the duty ratio of PWM waves used for controlling the low-temperature electric valve is calculated according to the input target temperature and the initial temperature of the refrigerating chamber; the controller controls the low-temperature electric valve to be conducted throughthe PWM waves, so that the liquid nitrogen is sprayed into the refrigerating chamber to complete refrigeration; and the controller is used for closing the low-temperature electric valve after the temperature of the refrigerating chamber reaches the target temperature. According to the liquid nitrogen refrigerating system and method, the spraying amount of liquid nitrogen is controlled through thePWM waves, and the temperature control precision of the liquid nitrogen refrigerating system can be effectively improved. The system and method can be widely applied to the technical field of refrigeration.

Description

Technical field [0001] The invention relates to the technical field of refrigeration, in particular to a liquid nitrogen refrigeration system and method for fishing boats. Background technique [0002] The current preservation technology of fishing boats includes cooling and freezing. Cooling and preservation is to reduce the temperature of the fish body to close to the freezing point of the juice in the fish body, thereby inhibiting and slowing down the activity of enzymes and microorganisms, so that the fish body can be used for a certain period of time. Keep good freshness inside. The temperature of the fish tank is generally between -5°C and 0°C, and the freshness period is between 10 and 27 days depending on the temperature and the type of fish. Freezing preservation is to freeze fish products below -18°C and inhibit the growth of bacteria to achieve longer-term preservation. The new technologies currently applied include low-temperature preservation, ultraviolet and ozone c...

AI Technical Summary

Problems solved by technology

This type of refrigeration unit system has complex structure, high maintenance costs, long pre-cooling time, and fuel consumption on board. For fishing boats that have been operating at sea for a long time, under the condition of strong moisture and corrosion, the operation reliability of the refrigeration unit must be ensured. , it is necessary to use more expensive units, which will increase the cost of maintenance; secondly, the refrigeration unit needs a lot of electricity, so it needs to consume more fuel and reduce the endurance of fishing boats

[0004] Therefore, some people have proposed to apply liquid nitrogen refrigeration technology on fishing boats to keep fresh, but at present, these technologies have the problem of inaccurate temperature control

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