A fully equipped automotive air-conditioning test system consists of 5 main components: a compressor, a condenser, an orifice tube, an evaporator and an accumulator. R-134a is used as refrigerant. The coefficient of performance, evaporator cooling capacity, compressor power consumption, total mass flow rate, vapor mass flow rate, liquid mass flow rate and oil in circulation, pressures and tempe...

This study presents thermodynamic analysis and optimization of single effect LiCl-H2O absorption cooling system. Thermodynamic models are employed in engineering equation solver to compute the optimum performance parameters. In this study, cut off temperature to operate system has been obtained at various operating temperatures. Analysis depicts that on 3.59 % rise in evaporator temperature, th...

In the first part of the present research, an R290/R600 mixture was tested as a drop-in substitute in a 20cubic-feet, single-evaporator, autodefrost, topmount, conventional domestic refrigerator/freezer. All the hardware remained the same, only the capillary tube was lengthened to achieve the optimum performance. The best result with an optimized R290/R600 blend was 6% savings compared to the b...

An experimental investigation was implemented to determine the capacity degradation due to non-uniform refrigerant and air flow distributions, and to assess the potential to recover the lost capacity via controlling refrigerant distribution between individual refrigerant circuits. The tests were performed on a three-circuit, threedepth-row, finned-tube evaporator. Refrigerant inlet quality, exi...

Fred Keller Split Systems Director The National Appliance Energy Conservation Act has established a minimum efficiency of 10 SEER for residential split system air conditioners and heat pumps. Approximately 50% of residential split system air conditioners are sold as replacements for units having much lower SEER levels, typically 5-9 Btu/W·h. This investigation assessed the detrimental affects t...

CORRELATIONS FOR heat transfer performance in sugar factory juice evaporators are important for benchmarking and prediction of evaporator set performance. The correlation recently proposed by Broadfoot and Dunn (2007) (B&D) is examined and comparisons are made between it and formulae currently being used, in particular with the ‘Australian typical’ correlation, using data from Australian and ov...

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford ...

This paper presents the benefits in capacity and performance of a hybrid control of expansion valves for two 5-ton (17.6 kW) domestic heat pumps (HPs) based on experimental results. The hybrid control, as proposed by Kim et al. (2008a), employs a primary expansion valve that provides most of the pressure drop, while small secondary/balancing valves in the distributor lines to the circuits of th...

A capillary pumped loop (CPL) is a closed two-phase loop in which capillary forces developed in a wicked evaporator passively pump the working fluid over long distances to dissipate heat from electronic and power sources. Because it has no moving parts and requires minimal power to sustain operation, the CPL is considered an enabling technology for thermal management of spacecraft. While the st...

A planar, silicon mini capillary pumped loop (CPL) was designed, built, and tested using recent MEMS technology to provide integral cooling and temperature control for electronics. This design featured three silicon fusion bonded wafers incorporating an evaporator, condenser, liquid line and vapor line, all of which were dry plasma etched. Grooves were etched in the condenser and evaporator to ...