SU721646A1 - Method of controlling cooling capacity of refrigeration machines - Google Patents

Description

one

This invention relates to the field of slaving technology, and in particular; to the method of controlling the refrigerating capacity of refrigerating machines with a multi-stage reciprocating compressor.

There is a method of controlling the cooling capacity of refrigeration machines with a multi-stage piston compressor by changing the number of operating compressor stages and choking freon in a valve installed on the compressor suction line, varying according to the temperature of the cooled medium W {and

The disadvantage of this method is that it does not exclude fluctuations of power consumption and does not provide the required accuracy of maintaining the temperature of the medium to be cooled.

The aim of the invention is to improve the accuracy of maintaining the temperature of the cooled medium at a given

level and exclusion of power consumption fluctuations.

This goal is achieved by measuring the pressure in the suction line of the compressor and changing the number of operating stages to determine this value, with the successive shutdown of each stage at the minimum pressure, and switching on at the maximum pressure corresponding to the operation of the compressor with this stage.

FIG. 1 shows a flow chart for adjusting the cooling capacity implementing this method, and FIG. Figure 2 shows the dependence of the cooling capacity on the pressure of vasi van to the compressor when the compressor is operated with a different number of stages.

Claims (2)

The block diagram contains compressor 1, electroforming coils 2 in the cylinders of the compressor stages, valve 3 throttling refrigerant at suction temperature sensor 4, sensor 5 booster, concentrator 6, thermo-regulating fan-7, evaporator 8, and amplifying and converting units 9 and 0 Regulation The choledup efficiency of this method is as follows. When the heat load on the evaporator decreases, control of the coldness of compressor of compressor 1 is carried out in proportion to valve 3 with throttles, OBaifflH refrigerant at the compressor intake according to the temperature of the cooling medium detected by sensor 4, while the suction pressure is reached; detected by sensor 5, corresponding to the compressor’s cooling capacity at a disconnected stage, this stage is disconnected by sensor 5 as a result of pressing the suction valve of the corresponding cylinder using an electromagnet coil 2. Regulation of the compressor’s cooling capacity continues to be proportional with valve 3 throttling the refrigeon according to the temperature of the cooled medium recorded by the sensor 4. FIG. 2, graphically representing / 1, the method of propionic-step regulation smoothing out a piston compressor in terms of cooling capacity — suction pressure in a compressor. Process ab (also Cg-y, d-e, gf) is a proportional change in the suction pressure to the compressor and, accordingly, cold-performance. When the cooling capacity is at points b and d, one first stage is disconnected (process 2-4). Regulation of cooling capacity in the range of points g-d continues to occur proporidonally by means of the same valve of throttling freon on the suction of the compressor. If the cooling capacity is equal at points outside, the next stage shuts off, and so on. With increasing load, the described process occurs in reverse order. Thus, measuring the pressure in the suction line of the compressor and changing the number of operating steps by this value has a positive effect, which reduces the fluctuations in power consumption and increases the accuracy of maintaining the temperature of the medium to be cooled. The use of this method will improve the efficiency of cooling systems. Claims The method of controlling the cooling capacity of chillers with a multi-stage reciprocating compressor by changing the number of operating compressor steps and refrigerating the refrigerant in the valve, installed on the suction line of the compressor, is variable so that, in order to improve the maintenance accuracy the temperature of the cooled medium at a given level and excluding fluctuations in power consumption, measure the pressure in the suction line of the compressor and from enenie number of working steps carried out on this value, the disconnection sequence Noe each stage is performed at a minimum pressure, and the inclusion of - at a maximum pressure corresponding to the kompreosora this stage. Sources of information taken into account in the examination 1. Vavreshok V.M. et al. Throttle controllers of pressure and temperature. - Refrigeration equipment number 3, 1976, p. 61. 2. Bykov A. and others. The use of refrigeration piston compressors with regulation of refrigeration production. in air-conditioning installations, - Refrigeration equipment number 8, 1976, p. 6 / / u to, V W rig. one , Pressure. Suction figure 2