screw compressors are used to produce the compressed air in the refineries. because of the frequent failures and high prices of these compressors, this research was done to determine the failure causes in one of these compressors. in this study and after about 603 working hours , female rotor compressor had been fractured. metallurgical and other experiments showed that the defect in cooling wa...

This study evaluates the performance of air source heat pump (ASHP) and ground source heat pump (GSHP) systems individually and as part of their associated heating and cooling distribution systems in two semi-attached houses. Over the monitoring period, the performance of both heat pumps exceeded manufacturer and EnerGuide ratings, with Coefficients of Performance (COPs) above 5 in the cooling ...

An air-conditioner driven by two compressors with different capacity was developed to improve energy efficiency by use high efficiency components and load matching. An algorithm for driving the two-compressor system was devised for optimum capacity modulation, and seasonal energy efficiency increased by 22%, when compared with that of a conventional air-conditioner of the same rated cooling cap...

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 paper will present the structure of the new system, the control scheme and its performance test results. In this new system, the damper in the conventional refrigerator is replaced by an additional cooling fan Thus, it uses two cooling fans: one (F-fan) is to provide cooled air for freezing compartment (F-compartment) and the other (R-fan) is for refrigerating compartment (R-compartment), ...

In this paper, the reasons of damage water pumps parts of the air compressor cooling system were studied. To reach this goal, the works like preparing metallographic samples, evaluation of structure, investigation of mechanical properties, the alloy parts detection and chemical analysis of deposit and corrosion products collected from the parts were performed. According to studies and results o...

A solar chimney is designed and tested to pump outside air through an underground cooling tube during summer for building cooling. Both theoretical analysis and experimental results show that the solar chimney can be used to power the underground cooling system during daytime without use of electricity. This paper presents the theoretical design principals of the solar chimney, detailed experim...

The performance of two long term replacements R-407C (HFC-32/125/134a (23%/25%/52%)) and R-410A (HFC-32/125 (50%/50%)) was compared to R-22 in a 10.5 kW (3.0 TR) residential central heat pump. The performance evaluations were carried out in a psychrometric calorimeter test facility located at NRC using the Canadian Standards Association (GSA) I Air-Conditioning and Refrigeration Institute (ARI)...

Presently, nearly 26,000 MW gas power plant and nearly 16,000 MW of combined cycle has been installed in the country. But their power output in summer reduces to a minimum, where most demand is required, compared to the winter season. The main reason for that is gas turbine dependence on the ambient air temperature. Since most of our country has warm and dry climates, cooling down the input air...

The air compressor plays an extremely important role in the production of air separation. It provides the required specifications of compressed air for the follow-up air separation processes. It is difficult for an air compressor system to achieve the on-site production requirements because it is a time-varying, delay and nonlinear complex system. Articles for air compressor control system desi...