Energy-saving control method for jet enthalpy gain heat pump vacuum freeze drying unit equipment with economizer

Abstract

The invention relates to an energy-saving control method for jet enthalpy gain heat pump vacuum freeze drying unit equipment with an economizer. The energy-saving control method for a control system is characterized by comprising the following steps of according to requirements of a food drying process, determining the temperature T1 of heating mediums entering an inlet of a heating partition board of a drying chamber; according to vacuum requirements of the unit equipment and the changes of the thickness of a surface frost layer of a water catcher in the operation process of the unit equipment, determining a functional expression of changes of evaporating temperature T3 of the water catcher in the running process of the unit equipment along with running time t; according to the functional expression of the changes of the evaporating temperature T3 of the water catcher along with the running time t, realizing energy-saving control through the opening degree of a main throttle valve, and speed adjustment of a jet enthalpy gain frequency conversion compressor; according to the evaporating temperature T3 of the water catcher and condensing temperature T2 of a condenser, obtaining the best opening degree of an auxiliary throttle valve corresponding to the main throttle valve under different opening degrees through experiment or theoretical arithmetic, and adjusting the opening degree of the auxiliary throttle valve, so that a refrigerating system is in the best energy efficiency ratio of the refrigerating system. The energy-saving control method disclosed by the invention has the advantages that the evaporating temperature of the water catcher can be dynamically adjusted according to the changes of the frosting thickness of the water catcher, energy-saving running of the jet enthalpy gain refrigerating system with the economizer is realized, and the refrigerating system runs in the energy-saving manner.

Description

Technical field [0001] The invention relates to an energy-saving control method of a vacuum freeze-drying combined equipment with an economizer and a jet-enhancing heat pump. Background technique [0002] The quality of the food dried by vacuum freeze drying equipment is better than the food dried by other drying methods, but the energy consumption is high during the processing. In the operation of vacuum freeze-drying equipment, on the one hand, the sublimation of the water in the dried food requires a lot of heat, on the other hand, the sublimation of the water in the water trap requires a lot of cold. Because the condenser of the refrigeration system that provides refrigeration for vacuum freeze-drying equipment emits a lot of heat during the refrigeration process, and this heat is greater than the heat required for food drying, some researchers have proposed to use the condenser heat of the refrigeration system as The heat source for food drying, such as heat pump vacuum fre...

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Problems solved by technology

At the same time, since the temperature required for heating the drying chamber is generally around 60°C, and the evaporation temperature of the refrigeration system is around -40°C, the refrigeration system must use cascade refrigeration, two-stage compression refrigeration or air jet enthalpy-enhancing refrigeration to meet the requirements, but this It also increases the difficulty of controlling the combined equipment

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