Performance calculating method of finned tube evaporator under frosting working condition

Abstract

The invention discloses a performance calculating method of a finned tube evaporator under the frosting working condition. The method comprises the following steps of: determining the operation working condition of the evaporator; setting the defrosting cycle t of the evaporator, the calculating time interval delta t and the initial frost layer thickness; dividing the evaporator calculating areas according to the user setting; calculating the initialization; solving a control equation of single calculating area i; judging whether frost is formed and calculating the surface temperature of the frost layer; updating the calculating parameter of the calculating area; updating the frost layer thickness and density of the calculating areas; and judging whether the calculation is ended or not. The calculating areas of the evaporator are divided based on a certain pipe length, the control equation in each calculating area is solved, and a high-speed calculating function of a computer is used, so that the performance predicating efficiency and accuracy are high under the preset working condition. By using the high-efficiency calculating speed of the computer, the frequency of experiments of the evaporator is greatly reduced, and the development cycle of the products is shortened.

Description

technical field [0001] The invention relates to a design technology of an evaporator in a cooling system, in particular to a performance calculation method of a finned tube evaporator under frosting conditions. Background technique [0002] Frosting is one of the most common phenomena in the fields of refrigeration engineering and refrigeration. Various large and medium-sized cold stores, small-scale refrigeration devices (such as quick-freezers, refrigerators, freezers, etc.), ship refrigeration devices, and ship refrigerated transport containers all have the problem of coil frosting of the refrigeration evaporator without exception. The formation of frost will narrow the air circulation channel, reduce the air volume, and increase the pressure loss of the air, which will eventually completely block the evaporator, seriously hinder the heat exchange between the air and the refrigerant, and reduce the amount of heat exchange; and the heat conduction of the frost layer itself...

AI Technical Summary

Problems solved by technology

However, the frosting condition has a great influence on the performance of the evaporator, and the method of heat test is also relatively complicated.

[0003] At present, in the design and development stage, the performance prediction of finned tube evaporators under frosting conditions is mostly based on previous experimental results and artificial estimation methods, resulting in low efficiency and low accuracy. There is a large gap between the performance of the evaporator and the required performance, resulting in a serious waste of raw materials

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