An Innovative Air Conditioning System for Changeable Heat Loads

Abstract

The efficiency of air conditioning (AC) systems depends on the operation of their air coolers at varying heat loads in response to current changeable climatic conditions. In general case, an overall heat load of any AC system comprises the unstable range, corresponding to ambient air processing with heat load fluctuations, and a comparatively stable part for subsequent air subcooling. Following from this approach, a rational design overall heat load is chosen to provide a maximum annular refrigeration capacity generation and divided into a comparatively stable basic part and a remaining part for ambient air precooling at changeable heat loads. The ambient air precooling mode with considerable heat load fluctuation needs load modulation, whereas the comparatively stable heat load range can be covered by operation at about nominal mode. According to modern trend in AC systems the load modulation is performed by varying refrigerant feed to air coolers in Variable Refrigerant Flow (VRF) system. But with this the problem of inefficient operation of air coolers caused by dry-out of inner walls at the final stage of inside tube refrigerant evaporation followed by dropping the intensity of heat transfer remains unsolved. As alternative approach of the heat load modulation in AC systems there is a concept of incomplete refrigerant evaporation with overfilling air coils that leads to excluding a dry-out of inner surface of air coils and is realized through liquid refrigerant recirculation by injector (jet pump).

Monitoring the efficiency of cooling air at the inlet of gas engine in integrated energy system

“…The efficiency of refrigeration chillers and the whole cooling systems can be increased through intensification of heat transfer in heat exchangers [23,24] first of all of refrigerant boiling in evaporators [25,26] and by application of advanced coolant (refrigerant) circuits with injector [23,27], evaporative [28,29] and two-stage cooling [30] with heat conversion in combined chillers [31].…”

Innovative combined in-cycle trigeneration technologies for food industries

“…The efficiency of cooling systems and chillers can be improved due to intensification of heat transfer in evaporators [26] and condensers [27], advanced scheme decisions [28,29], deep utilization of exhaust heat [30][31][32] with low temperature condensation [33,34] to enhance the heat for conversion into refrigeration.…”

Alternative variable refrigerant flow (VRF) air conditioning systems with rational distribution of thermal load

“…A lot of publications focused to improve the efficiency of ACS by intensification of heat transfer in evaporators [1][2][3], advanced scheme of ACS [4,5] and RM [6,7], vapour ejector [8][9][10], liquid injector or jet pump [11,12] and thermopressor [13,14] technics. Numerous * Corresponding author: nirad50@gmail.com researchers studied the efficiency of ductless Variable Refrigerant Flow (VRF) systems [15,16].…”