Dimethyl ether is one of the derivative products coal that will be used as a household fuel substitute for LPG in Indonesia. In addition, it can also working fluid refrigeration system. To understand behavior this refrigerant, simulation was carried out to determine flow pattern dimethyl horizontal evaporator. This study applied an evaporator air conditioner with inside diameter 6.3 and 7.9 mm ...

This paper presents the results of the analysis of an ejector refrigeration system operating with Freons as the working substance. Such a system is suitable for operating at subzero evaporator temperatures. The mass of motive refrigerant vaoour per hour per ton and the coefficient of performance are calculated for various assumed operating parameters such as boiler temperature, evaporator temoe...

The capacity control of a vapor-compression refrigeration system is investigated for three different capacity control schemes. In a hot-gas by-pass control scheme, the refrigerant is by-passed from the compressor and injected back into the suction line to decrease the cooling capacity, whereas in cylinder-unloading scheme, one or more cylinders are unloaded to decrease the refrigerant mass flow...

The expansion device is the critical component of micro-to-small scale organic Rankine cycle (ORC) systems, substantially affecting system efficiency and cost. Low isentropic lubrication requirements are main issues associated with using volumetric expanders in ORC systems. Despite contributing to reducing internal leakages an expander, it may compromise performance by adversely evaporator’s th...

In this study, an enhanced heat pipe performance for grooved pipes has been demonstrated through capillary boosting with the introduction of bifurcation grooves. Wider grooves regularly branch to narrower such that total cross-sectional liquid flow area remains approximately same. Following computational framework drawn by a recently developed analysis toolbox (H-PAT), we develop numerical mode...

Denis CLODIC Centre d'Energetique ·Ecole des Mines de Paris 60, boulevard Saint-Michel· F • 75272 PARIS Cedex 06 A test bench has been developed consisting in an open display-case and a refrigerating system composed mainly of four hermetic compressors, an air cross-current condenser and an evaporator. The evaporating temperature of -40°C allows to keep the temperature of the products at ·18°C f...

Studied is a kind of NH3/CO2 two-stage low temperature refrigeration system, in which NH3 is used as the refrigerant in the high-temperature stage and CO2 is used as the refrigerant in the low-temperature stage. The performance of the system is simulated and analyzed by changing the mean temperature of the evaporator-condenser and the temperature of the condenser. The mean temperatures of the e...

The National Renewable Energy Laboratory (NREL) has developed a transient air conditioning (A/C) system model using SINDA/FLUINT analysis software. It captures all the relevant physics of transient A/C system performance, including two-phase flow effects in the evaporator and condenser, system mass effects, air side heat transfer on the condenser/evaporator, vehicle speed effects, temperature-d...

In this study, the experimental performance of use R1234yf refrigerant al-ternative to R134a in an automobile air conditioning system with var-iable capacity compressor was investigated. The conditioner con-sists a variable compressor, evaporator, condenser, liquid tank and expansion element. is equipped computer-aided control systems obtain desired conditions data col-lection for measuring col...

cyproterone acetate (ca) has been loaded to liposome by solvent evaporation and thin film formation technique. the effects of some formulation variables such as temperature of organic solvent evaporation, rotary evaporator speed, volume of organic solvent, volume of balloon and temperature of hydrating buffer has been evaluated. the data showed that bigger balloon with higher surface area has b...