SU943502A1 - Device for automatic control of thawing air cooler of regrigerating-heating machine - Google Patents

Description

(54) AUTOMATIC CONTROL DEVICE DEFROSTING THE AIR COOLER REFRIGERATING AND HEATING

1.2

The invention relates to refrigeration equipment, namely to automatic devices for 5Gettling by defrosting the air-cooler of a refrigerating-heating machine.

A device for automatically switching an air-cooler of a refrigerating machine to a heating mode is known, which contains a time switch included in the electric supply circuit of a refrigerator {1).

However, such a device does not allow timely determination of the optimal time for switching on the defrosting system of the air cooler, since the time interval between defrost starts is constant and the physical parameters of the air in the cooled volume are not taken into account and the operation time of the refrigeration unit is not taken into account.

The closest to the invention to the technical essence and the achieved result is the device for automatic control of defrosting the air cooler of the cooling and heating machine, containing a series-connected defrosting unit and a control unit1 and connected to two outputs of the MACHINE

mi with a compressor and heater connected to the air cooler, and a relative humidity sensor {; 2.

The disadvantage of this device lies in the rigid cycle of switching on, defrosting, independent of the operation time of the compressor of the refrigerating machine, and the effect of the air temperature in oh; 1 each volume on the formation of a snow coat on the active surfaces of the air cooler is not taken into account.

The purpose of the invention is to improve the accuracy of determining the moment of defrosting and the reduction of energy consumption.

The circuit is achieved in that the automagical defrosting control device of the air cooler of the chillers of the refrigerating-heating machine contains a series-connected defrosting unit and a control unit connected to the dual outputs with the KOMnpeccoffoM and the heater connected to the air cooler, and the relative humidity sensor is equipped with a temperature sensor, a pulse generator , two schemes I. and a reversible counter, with 394 IJTOM temperature sensor and relative humidity sensor connected to the input of the pulse generator, the output is the last It is connected with one of the inputs of each AND circuit, another input of each AND circuit is connected to the first and second inputs of the control unit, the output of the first AND circuit is connected to the summing input of the reversible counter, the output of the second AND circuit is connected to the subtracting input of the reversible counter, and The last input is connected to the input of the defrosting unit. The drawing shows the functional scheme of the proposed device. The device consists of a cooling machine I machine 1, which includes a series of defrost 2 and a control unit 3 connected in series, two outputs connected to a compressor 4 and a heater 5 connected through air- and pipes with an air cooler 6. The input of the defrost block 2 is connected to a reverse output counter 7, the summing and subtracting inputs of which are connected respectively to the outputs of the circuits AND 8 and 9, while the first inputs of the circuits AND are connected respectively to the first and second outputs of the control unit 3, and the second are connected to eratoru pulses of the pulse generator 10. The two inputs 10 CONNECTION Nena to temperature sensors and humidity iotnositelnoy O device 12 operates as follows. When the air temperature in the room in which the refrigerating heating machine 1 is installed rises above the norm, the control unit 3 turns on the compressor 4 and the air passing through the air cooler 6 begins to decrease the room temperature and simultaneously form frost on the walls of the air cooler 6. At the same time a signal to start cooling from the first output of the control unit 3 opens the first circuit, AND 8, as a result of which the pulses from the pulse generator 10 pass to the summing input of the reversible counter 7, which starts the slave accumulation during the whole time while the refrigerating-heating machine 1 operates in the cooling mode, which causes formation of frost on the walls and pipes of the air-cooler 6. When the compressor 4 is stopped, the pulse counting stops as the prohibitory signal comes from the first output control unit 3. The moment of defrost activation is determined by the overflow pulse of the reversing counter 7, which is fed to the defrost unit 2, after which the defrosting valves of the heating and heating compartment 1 are turned on. is lowered the room temperature below the normal control unit 3 includes a heater 5, and the warm air passing through the cooling coil 6 begins to increase the temperature in the room and simultaneously partially thaw the frost. The signal from the second output of the control unit 3 opens the second circuit AND 9, as a result of which the pulses from the pulse generator 10 are passed to the subtractive input of the reversible counter 7. The counter size of the counter can change the interval between defrosting, which allows the device to be used for refrigerating machines of any refrigerating capacity. As a result, the reversive counter 7 summarizes the pulses, the number of KOTopbix and the compressor compressor operation time 4, when accumulation takes place, does not subtract the pulses, the number of which is proportional to the operating time of the heater 5, when partial defrosting occurs, and does not time out, when the compressor 4 And heater 5 does not work, i.e. air temperature is in the normal range, while frost is not. is formed. The physical properties of air in the cooling volume are taken into account by the fact that the pulse frequency of the pulse generator 10 is directly proportional to the relative humidity of the air and the temperature inside the room. An increase in the relative air humidity measured by the sensor 12 increases the rate of frost formation, and an increase in temperature measured by the sensor 11 increases the moisture content, which also leads to an increase in the rate of frost formation. Sensors 11 and 12; connected to the pulse generator 10 in such a way that the pulse frequency from its output is. the stroke was proportional to the indications of sensors 11 and 12. With an increase in the pulse tracking frequency, overflow of the reversible counter 7 occurs faster, with the result that the defrosting of the air cooler 6 is turned on earlier. In the case of a decrease in the relative humidity and air temperature in the room, the frequency of the pulses decreases and the defrost turns on later. . The use of the proposed device makes it possible to reduce the consumption of energy by about 10% as compared with the known technical solution due to timely removal from the active surfaces of the cooling device and increase, thereby, of the cooling capacity of the machine. In addition, the accuracy of determining the moment of switching on defrosting is ensured, the possibility of unjustified inclusions of defrosting is excluded, which also leads to energy savings and increased reliability and durability.

the corresponding machine nodes, the number of inclusions of which is reduced.

Claims (2)

1. Gogolin A. A., et al. Brazing air coolers. M., DaIITAI somolprom, 1972, p. 23-24. 2. US patent number 3759049, class. 62-80, publ. 1972 (prototype).