EXPERIMENTAL STUDY AND MINIMIZATION OF (LMTD) OF A REFRIGATOR BY BALANCING COOLING WATER

Abstract

This work involves an experimental investigation of the refrigerator equipment. To complete of the study model, an inside and outside temperatures of refrigerant (R12) and cooling water through heat exchanger is assumed to be steady state flow. Special tables of refrigerant (R12) and cooling water are used to know properties at specified temperature , by using refrigeration system basically which work between two pressures, and specific enthalpy is one of the most useful properties which it is need in energy equation application to determine condenser and evaporator tube length of system , which takes as carefully to compression system design for giving temperature difference in cooling or heating systems. Also, tube length of condenser and evaporator are calculated (18 , 9) m respectively. A pressure - specific enthalpy or (p-h) chart of refrigerant R12 is depended on to determine specific enthalpy for each run at present pressure. This investigation is to study the influence of the volume flow rate of cooling water as range (2,4,6,and 8) liter /min which it supplies by control valve to the heat exchangers of system on logarithm mean temperature difference (LMTDe) and cooling coefficient of performance. Also, this work investigates the minimization of the (LMTDe) evaporator by using valve controlled of cooling water. The present results show that, the degree (LMTDe) is decrease as the volume flow rate of cooling water increasing then, due to increase of refrigerating effect at same time cooling coefficient of performance (COP)RF is increasing. Also, in the compression cooling system has been get temperature difference about(6)◦C. Comparison between the obtained experimental performance results and the previous theoretical work shows a good agreement with (±3.8) percentage.