Thermal expansion valve

Abstract

The invention relates to a thermal expansion valve which comprises a valve body. The valve body comprises an inlet port, a valve chamber, a valve hole, an outlet port and a reflux channel, wherein the inlet port is used for importing a high pressure refrigerant; the valve chamber is communicated with the inlet port; the valve hole is arranged in the valve chamber; the outlet port is used for exporting out the refrigerant expanded due to opening and closing of the valve hole; the reflux channel is used for the refrigerant which flows through an evaporator and is returned towards a compressor; a valve rod is arranged in the valve body in a sliding mode and passes through the reflux channel and the valve hole, one end of the valve rod is connected a valve element and the other end of the valve rod is pushed by a thermal element so as to control the opening of the valve hole; the valve hole is a horn hole and comprises a section of cylindrical hole and at least two adjacent cone holes which are provided with gradually enlarging openings and are connected with one end of the cylindrical hole; and when the valve element is in contact with the side walls of the cone holes, the valve hole is closed. Compared with the thermal expansion valve in the prior art, the thermal expansion valve disclosed by the invention has the advantage that the matching problem of a low-superheat-degree air conditioning system under the high-load and low-load working conditions is solved.

Description

technical field [0001] The invention relates to the field of automobile air conditioners, in particular to a thermal expansion valve. Background technique [0002] Thermal expansion valve (TXV) is a throttling component commonly used in automobile air conditioners. It throttles and reduces the high-temperature and high-pressure liquid refrigerant from the condenser into a low-temperature and low-pressure liquid refrigerant, and sends it to the evaporator according to the degree of superheat at the outlet of the evaporator. refrigerant flow. The principle of the thermal expansion valve's control of the refrigerant flow is that the air box head senses the superheat of the evaporator outlet, and the valve hole is driven to open and close by the pressure difference caused by the superheated refrigerant and the saturated refrigerant in the air box head. So that as much refrigerant as possible enters the evaporator, so that the evaporator can maximize its performance. [0003] F...

AI Technical Summary

Problems solved by technology

This also leads to excessive flow at low load conditions, causing system pressure fluctuations, noise

Since the refrigerant at the outlet of the evaporator often has no superheat, the valve hole of the thermal expansion valve is at a small opening position that seems to be open but not open, and the instability of the valve hole is likely to cause system pressure fluctuations and noise.

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