Refrigeration system with filling level monitoring function

Abstract

The invention relates to a method and device used for monitoring refrigerant charge in a refrigerant loop (46) of a refrigeration system; the refrigeration system (10) comprises a compressor (12), a condenser or a gas cooler (14), an expansion device (16) and an evaporator device (18); when the compressor (12) is closed, the method comprises the following steps: measuring at least one temperature, and measuring refrigerant pressure in the refrigeration system; if the measured pressure is out of a nominal pressure scope, determining the refrigerant charge error, when the refrigerant is not enough, the refrigerant nominal pressure is determined according to the measured temperature, and the nominal pressure scope comprises the pressure value having the most regulated deviation from the nominal pressure; when the compressor is opened, the method comprises the following steps: measuring at least one temperature; measuring refrigerant pressure in the exit of the condenser or gas cooler; if the measured pressure is out of the nominal pressure scope, building the refrigerant charge error, especially the refrigerant is not enough, wherein the refrigerant nominal pressure is determined according to the measured temperature, and the nominal pressure scope comprises the pressure value and the pressure value having the most regulated deviation from the nominal pressure; the device also comprises a container (22) used for storing refrigerant; the refrigerant is specially CO2; the device runs in a cross critical range according to work points; at least one refrigerant temperature sensor (32) and at least one refrigerant pressure sensor (34) are provided so as to measure the temperature and pressure of the refrigerant; the refrigerant temperature and pressure can be evaluated in the mode in a control unit (30), so the refrigerant charge error can be detected if the insufficiency is detected, the control unit can control medium on the refrigerant loop (46) so as to start filling.

Description

technical field [0001] The invention relates to a method for monitoring the refrigerant charge of a refrigerant circuit of a refrigeration system to fill such a refrigeration system with refrigerant and to a device, in particular for a vehicle, for monitoring a refrigeration system refrigerant charge. Background technique [0002] Compression refrigeration systems or air-conditioning systems are used as air-conditioning systems, for example, in air-conditioned vehicles, such as cars or buses, in order to reduce the temperature inside the vehicle. A compression refrigeration system of the type described above comprises a refrigerant delivery system having a condenser unit comprising at least one condenser or at least one gas cooler, in addition to an expansion device, an evaporator unit and a compressor through which the refrigerant Conveyor lines are connected together. Refrigerant circulates in this closed circuit. [0003] According to environmental compatibility, carbo...

AI Technical Summary

Problems solved by technology

[0009] Whereas the known methods from US5481884 and DE10061545A1 can indeed be applied in principle to any refrigerant and thus also to CO 2 , but the method only identifies the wrong refrigerant state at the compressor inlet, i.e. on the low pressure side

However, error states can also arise, for example, due to a defective expansion part or a blockage of the refrigerant circuit

Both possible failures pose a serious risk to the compressor

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