Compressor performance for liquefied natural gas (LNG) main refrigeration units is very important due to the direct link between compressor efficiency and LNG production for a fixed amount of power. Dresser-Rand recently designed a series of new stages for the LNG market that provided improved efficiency and a wider range of operation. Industry practice is to rig test new stages prior to applic...

Magnetocaloric refrigeration is an alternative refrigeration technology with significant potential energy savings compared to conventional vapor compression refrigeration technology. Most of the reported active magnetic regenerator (AMR) systems that operate based on the magnetocaloric effect use heat transfer fluid to exchange heat, which results in complicated mechanical subsystems and compon...

After the Great East Japan Earthquake, the saving energy became the one of the most important issues. Especially, saving the electrical power for air-conditioning at summer time is a problem of great urgency. We have been developing the ejector refrigeration system which can improve coefficient of performance of refrigeration systems by converting exhausted expansion energy into useful pressure...

Fluorinated hydrocarbon refrigerants have especially in Europe been drawn into the focus of the public debate concerning the background of reducing greenhouse active substances. This debate concentrates mainly on the GWP (Global Warming Potentials) properties of the substances. To step forward from a material based discussion to a useful dialogue about substances in their respective application...

The energy consumption by heating, ventilation, air conditioning, and refrigeration systems forms a large portion of the total energy usage in buildings. Vehicle fuel consumption and emissions are also significantly affected by air conditioning. Air conditioning is also a critical system for hybrid electric vehicles and electric vehicles as the second most energy consuming system after the elec...

The purpose of this research is to investigate thermoeconomic optimization and exergy analysis of transcritical CO2 refrigeration cycle with an ejector. After modeling thermodynamic equations of elements and considering optimization parameters of emerging temperature of gas of cooler (Tgc) , emerging pressure of cooler's gas (Pgc) , and eva...

Cryosurgery is a technique for destroying undesirable tissue, such as cancers, by exposing it to a very low temperature. This paper presents a thermodynamic modeling tool that has been developed for a two stage, mixed gas Joule-Thomson (MGJT) cryoprobe used for cryosurgery. A conventional vapor compression (VC) cycle using a pure refrigerant precools the MGJT cycle providing refrigeration at th...

The paper focuses on the operation of simple refrigeration cycles. With equipment given, there are, from a control and operational point of iew, five steady-state degrees of freedom; the compressor power, the heat transfer in the condenser, the heat transfer in the evaporator, the choke alve opening and the active charge in the cycle. Different designs for affecting the active charge, including...