Method for operating a rotational-speed-variable refrigerant compressor

Abstract

The invention relates to a method for operating a rotational-speed-variable refrigerant compressor (2) for cooling a cooling volume (4) of a refrigeration system (1), which refrigeration system does not have its own control unit, wherein the refrigeration system (1) comprises at least one thermostat (3) for directly or indirectly monitoring a temperature state of the cooling volume (4) and wherein the rotational-speed behavior of the refrigerant compressor (2) during a cooling cycle is controlled by means of a specification rotational-speed control stored in an electronic control device (6) of the refrigerant compressor (2). According to the invention, in order to enable adjustment of the rotational-speed behavior in reaction to a preceding special operating state and to enable energy-optimized cooling of the cooling volume (4) that is as fast as possible, at least one comparison parameter is stored in the electronic control device (6) of the refrigerant compressor (2) and exceedance or undershooting of the comparison parameter by a current measured parameter value is monitored, a special cooling cycle different from the specification rotational-speed control is triggered if the current measured parameter value exceeds or undershoots the comparison parameter, possibly, a current cooling cycle controlled by means of the specification rotational-speed control is interrupted by the special cooling cycle.

Description

FIELD OF THE INVENTION[0001]The invention concerns a method for operating a refrigerant compressor having a variable rotary speed for cooling a cooled volume of a refrigeration system, wherein the refrigeration system comprises at least one thermostat for direct or indirect monitoring of a temperature state of the cooled volume and wherein the refrigerant compressor is operated cyclically and a cooling cycle of the refrigerant compressor begins when the refrigerant compressor is set to an ON state by a switching signal triggered by the thermostat, and the cooling cycle ends when the refrigerant compressor is set to an OFF state by another switching signal triggered by the thermostat, wherein an operating cycle comprises, in addition to the cooling cycle, a rest cycle that follows the cooling cycle, and wherein the rotary speed behavior of the refrigerant compressor is controlled during a cooling cycle by means of a preset rotary speed control that is stored in an electronic control ...

AI Technical Summary

Benefits of technology

This patent describes a method for controlling a refrigerant compressor in a refrigeration system that automatically detects when there was a power outage and a cooling cycle is needed. The method uses a temperature measurement device already in the control device of the refrigerant compressor for this purpose. The control device stores the temperature measurements and current operating state of the compressor over time to accurately monitor and model its behavior. The method also involves operating the compressor at a high rotary speed for a short period of time to ensure that it provides a high cooling output. The invention simplifies the installation process of the control device in a refrigeration system without the need for a control unit to transmit signals to the compressor.

Problems solved by technology

A disadvantage of the control of the prior art lies in the fact that the electronic control device of the refrigerant compressor is not capable of reacting to any special operating states such as an increased cooling demand after a defrost operation or after a power outage.

The refrigerant that is in the evaporator unavoidably becomes heated during the defrost operation.

Another problem in simple refrigeration systems results from the fact that simple refrigeration systems are often operated in regions with weak infrastructure, in which a steady supply of electricity is not guaranteed, rather interruptions of the electricity supply are the order of the day.

This results in the length of the cooling cycle that follows the special operating state being disproportionately higher than the duration of the preceding cooling cycles and an increased energy consumption of the refrigerant compressor resulting from the long duration of the cooling cycle.

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