Many industrial processes need steam at temperatures from 100 to 200 °C, normally produced by directly heating water via coal, natural gas or oil combustion. Nevertheless, large amounts of unused heat below 100 °C are wasted in other industrial processes. In principle, a high-temperature...

HCFC-22, widely used in variety of refrigerating/heating equipment, has been scheduled to be phased out by Montreal Protocol. This decision will result in significant reduction of ozone depletion and global warming, holding on the climate benefits accrued so far. In this paper, significant...

This paper analyzes the properties of wavelet transform and its potential application in detecting the leakage location of gas pipeline. An entity-part method, which is proposed for the accurate leaking point, has been proved valid in the stimulation experiment. In addition, method of Romberg...

Frost accumulation on evaporator decreased cooling capacity and COP (coefficient of performance) of cold storage refrigeration system, so timely and effective defrost was significant to cold storage energy-saving operation. The EHD (electric heat defrosting) method was commonly used in cold...

The LFL (lower flammable limit) and UFL (upper flammable limit) of R1150 were researched experimentally on a self-made test rig according to the Chinese National Standard GB/T12474 under variable temperature and humidity conditions. Results showed that the LFL increased with the decrease of...

The dynamic behavior of the PEM (proton exchange membrane) fuel cell stack has great effect on the safety and effective operation of its applications. In this paper, a self-designed bulb-array is used to simulate the various loading conditions and study the dynamic behavior of a 2 kW PEM fuel...

We describe a new air-conditioning and heat-pump system, which may be used to separate a refrigerant mixture efficiently and adjust the composition in the system with cooling- or heating-load changes. A dynamic model has been developed to analyze the transient behavior of the capacity-control...

A heat-pump system for heat recovery at substations is analysed. The analysis and test results show that the system yields substantial energy savings and reduces pollution.

Thermodynamic properties and refrigerating performance for the alternative R32/134a mixtures in water-to-water heat pumps have been analyzed. Also, its dynamic model and flammability during the leakage process have been investigated. The results show that R32/134a (30/70) is a good alternative...

The R22 alternatives R32/125/152a and R290 and their mixtures have been analyzed and evaluated in a room air conditioner. The cooling capacities, energy efficiencies, compressor-discharge temperatures, and pressures of alternatives have been compared with R22. R32/125/152a mixtures were found to...