A Modeling Study on the Operational Stability of a Variable Speed Direct Expansion Air Conditioning System
نویسندگان
چکیده
This paper reports on a modeling study on the operational stability of an electronic expansion valve (EEV) controlled variable speed (VS) direct expansion (DX) air conditioning (A/C) system. An existing detailed, physical based dynamic model for a VS DX A/C system was further developed by adding equations for EEV’s temperature sensor. Using this further developed model, a modeling study on the stability of a VS DX A/C system based on the classical minimal-stable-signal (MSS) theory was carried out. The influences of the dynamics of EEV’s temperature sensor and the variable speed operation on the operational stability of the VS DX A/C system were investigated. The modelling results suggested that slowing down the rate of degree of superheat (DS) signal transfer would help mitigate the instability, while increasing the compressor speed or decreasing the supply fan speed would cause the movement of a mixture-vapor transition point towards evaporator exit, leading to potential instability of the VS DX A/C system.
منابع مشابه
A New Control Approach for a Direct Expansion (DX) Air Conditioning (A/C)System with Variable Speed Compressor and Variable Speed Supply Fan
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