liquefied natural gas (LNG) is the most economical way of transporting natural gas (NG) over long distances. Liquefaction of NG by using vapor compression refrigeration system requires high operating and capital cost. Due to lack of systematic design methods for multistage refrigeration cycles, the conventional approaches of determining optimal cycle configuration are mostly based on trial-an...

This paper presents the experimental research into the evaluation of lubricity for polyolester (POE) lubricant with HFC-134a refrigerant in rotary and reciprocating compressors for household refrigerators. In order to evaluate the lubricity for POE lubricant with HFC-134a refrigerant, we conducted 4-balls wear tests in the mixing environment of POE lubricant and HFC-134a refrigerant. In the pre...

Continuous capacity modulation, for example by varying compressor speed, is only one alternative to conventional cycling of vapor compression systems. Cycling the compressor at higher frequencies (~0.01–0.1 Hz) than conventional systems (~0.001 Hz) offers a potentially simpler and less costly alternative. Experiments were conducted to quantify effects of steady vs. pulsed flow on the performanc...

This paper compares two alternative approaches to the transient simulation of vapor-compression air-conditioning cycles that use different descriptions of the thermofluid behavior on the refrigerant side of the heat exchangers. While one of the most common modeling assumptions for two-phase refrigerant flow in transient cycle simulation is that the liquid and gas phases travel at the same veloc...

This research is aimed to define , (1) the effects of refrigerant to the environment, (2) derive the eco friendly refrigerants by using software REFPROP, (3) describe the properties of refrigerant by mixing them in appropriate percentage, (4) reducing GWP and ODP by providing suitable substitute of CFC’s and HCFC’s refrigerants, (5) reducing the effect of refrigerant to the ODP. This analysis i...

Sonny G. Sundaresan Copeland Corporation Sidney, Ohio, U.S.A. HCFC 22 currently used in Air-Conditioning and Heat Pump applications, is being replaced by R407C and R410A, both HFC 32 based blends. Scroll compressors are being developed to meet the improved efficiency and other system performance requirements in Air-Conditioning and Heat Pump products in North America, Europe and Asia-Pacific. L...

Vapor absorption refrigeration system efficiently could be driven by the low grade renewable heat associated with the exhaust gas from the car engine, and uses the eco-friendly refrigerant, i.e. water. The absorption cycle, however, has not yet obtained much attraction in the automobile application due to its large volume and weight per unit of cooling capacity, which has limited to use. A micr...

After almost 20 years of intensive research on magnetocaloric effects near room temperature, magnetic refrigeration with first-order magnetocaloric materials has come close to real-life applications. Many materials have been discussed as potential candidates to be used in multicaloric devices. However, phase transitions in ferroic materials are often hysteretic and a metric is needed to estimat...

Solar Energy Applications Laboratory , Colorado State University . Fort Collins , CO 80523 Design of a vapor transport solar water heater using R-123 is optimized to maximize thermal performance and minimize life cycle cost. Optimal systems for one and twostory homes are identified in a parametric study of collector area, condenser heat transfer area, water storage tank volume and circulating r...

Liquefying hydrogen is an efficient way to store and transport hydrogen. However, the liquefaction process energy intensive. Therefore, integrated of natural gas utilizing mixed refrigerant cycle Claude proposed. The not only couples a steam methane reforming produce carbon dioxide refrigeration assist in pre-cooling, but also employs solar absorption system enhance efficiency. proposed simulat...