Patent ID: 6453690
Filing Date: 2002-09-24
Classification: F25B,Y02B

Abstract:
A method for controlling a linear expansion valve in an air conditioning system with two compressors of a large compressor and a small compressor, comprising the steps of:(a) changing an LEV pulse value from an initial value to P1, when a compressor operation time period reaches to Ts-a after the compressors are put into operation; (b) changing the LEV pulse value from P1 to P2, when the compressor operation time period reaches to Tm-b; (c) changing the LEV pulse value from P2 to a target value, when the compressor operation time period reaches to T1-c; and, (d) starting a superheat control, after the operation time period of the compressors reaches to T2, where P1 denotes an initial pulse value+ a capacity ratio (%) of the small compressor x the target value/100, denotes an initial pulse value+ a capacity ratio (%) of the large compressor x the target value/100, T1 denotes a time period to reach to the target value, T2 denotes a time starting to control superheat, Ts denotes a capacity ratio (%) of the small compressor x T1/100, Tm denotes a capacity ratio (%) of the large compressor x T1/100, â€˜aâ€™ denotes a time period the LEV pulse is changed from the initial value to P1, â€˜bâ€™ denotes a time period the LEV pulse is changed from P1 to P2, and â€˜câ€™ denotes a time period the LEV pulse is changed from P2 to the target value.