The method of defrosting the evaporator of the refrigeration machine

 

(57) Abstract:

Usage: in refrigeration, in particular in the steam refrigeration machines and can find application in refrigeration equipment for the food and dairy and meat industry, trade and public catering, refrigerated transport. The inventive method of defrosting the evaporator of the refrigeration machine is for heating the evaporator to the minimum value of the temperature of the thawing and subsequent cyclic heating it until after thawing. When this subsequent heating is carried out for a specified time period and in the specified temperature range. 2 C. p. F.-ly, 3 ill.

The invention relates to refrigeration, and in particular to steam refrigeration machines, and can find application in refrigeration equipment for the food and dairy and meat industry, trade and public catering, refrigeration transport.

Known methods of operation of the refrigeration machine including an evaporator defrost command by continuous heating of its heater within the specified time (see the book by A. A. Gogolin, Y. I. Colote. Defrost unit coolers. Browse M. Niitakayama, 1972, S. 11,incorporating a refrigerating machine in an operating mode in redoutable evaporator, after several cycles of operation mode and thawing will cause an avalanche overgrowing evaporator frost and, as a consequence, failure of the refrigeration machine. It is also possible (with a slight freezing evaporator) excessive heating of the evaporator for a given strictly specified period of time, causing an overload of the refrigeration machine and lead to the violation of storage refrigerated products, which does not allow to achieve a technical result.

Closest to the invention is a method of operation of the refrigeration machine including an evaporator defrost command by continuous heating before reaching the minimum temperature of the beginning of the thawing point of control and subsequent continuous heating before reaching the point of temperature control, obviously the greater the temperature at which there is a release of the evaporator from frost (see the book of L., Kaplan. Commercial refrigeration equipment, Meters, Light and food industry, 1983, S. 164). When implementing the known method, due to the fact that during the defrosting of the evaporator is heated to a temperature that is certainly greater the temperature at which there is a release of the evaporator from freezing, when privnesenie heat in the cooled volume, that leads to an overload of the refrigeration machine and allows you to get the desired effect.

The objective of the invention exclusion of excessive introduction of heat into the cooled volume with a guaranteed assurance defrost the entire surface of the evaporator, and determines the technical result of the claimed method.

The essential features and sufficient in all cases to which the requested scope of legal protection are shared with the prototype defrosting the evaporator on the team by continuous heating to achieve at the point of minimum control temperature of the beginning of the thawing and subsequent heating, which, according to the invention, carried out cyclically.

The features characterizing the invention in particular cases, based on subsequent heating for a specified period of time, and it is turned on and off when the temperature at the point of control, respectively, the minimum and maximum within a specified range.

Between the set of essential features and obtain the technical result there is a causal relationship because the distinctive features not identified in any of the ri guaranteed provision defrost the entire surface of the evaporator, is achieved only by joint use of any and all signs of restrictive and distinctive parts of the formula.

In Fig. 1 shows a diagram of a refrigerating machine of Fig. 2 is a sequence diagram of the operation of the machine at a known (a) and proposed (b) methods; Fig. 3 - graphs of the variation of the temperature of the evaporator during the refrigeration machine is known (a) and proposed (b) methods.

Refrigerating machine includes a compressor 1, a condenser 2, a receiver 3, an inductor 4 and the evaporator 5, equipped with heaters 6. The inductor 4 and the evaporator 5 is placed in the cooled volume A.

The method of operation of the refrigeration machine is implemented as follows.

In the operating mode compressed in the compressor 1 refrigerant vapors enter the condenser 2 where it condenses into liquid, which enters the receiver 3. Then, the liquid refrigerant passes through the orifice 4, which extends, and is sent into the evaporator 5, where boiling, cooling the air in the volume of A.

During operation of the refrigeration machine is in the working mode, the moisture in the cooled volume And precipitated in the form of frost on the finned-tube evaporator 5. The most likely uneven growth of the evaporator 5 frost. After completing the ri achievement of the evaporator 5 in the control point the minimum temperature at the start of the defrost t15oC, the heater 6 is transferred to the cyclical mode of operation, during which they will turn off when reaching into the point of control of the maximum temperature within the specified range, for example, 10oC, and included in the cooling of the evaporator 5 to the minimum temperature, for example, 5oC.

Cyclical heating of the evaporator 5 heater 6 is carried out for a specified time period, if before the end of this period after the next shutdown of the heater 6 is not cooling the evaporator 5 to the temperature t1the heaters 6 do not include, and before the end of the period of the cyclic operation of the heating of the evaporator 5 is not produced.

After a period of cyclical heating include working mode.

1. The method of defrosting the evaporator of the refrigeration machine, which consists in heating the evaporator to the minimum value of the temperature of the thawing and subsequent heating up to the end of defrosting, wherein the subsequent heating are cyclical.

2. The method according to p. 1, characterized in that subsequent heating to produce within a specified period of time.

3. The method according to PP. 1 and 2, characterized in that subsequent heating of the lead in

 

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