Efficiency, compressor

High efficiency compressors with crankcase heaters... 

Commercial refrigeration - Alternatives to CFCs for new commercial refrigeration equipment include HCFCs (including HCFC mixtures) and HFCs and HFC mixtures. Retrofit of existing equipment is possible by using both HCFCs and HFCs, in conjunction with reduced charges and more efficient compressors. Hydrocarbons are, to a limited extent, applied in hermetically sealed systems. 

Figure 12-6G. AJAX APV-1000, high-efficiency compressor valve. Suction and discharge losses are 4-8% compared to conventional valves with losses of 6-20% as a percentage of the total indicated horsepower. (Used by permission Bui. 2-214. Cooper-...

Much attention has been given in recent years to the power consumed in the refrigeration process and the development of more efficient compressors. A few points to consider are ... 

Estimate the compressor efficiency. Compressor manufacturer s data should be used where possible. If this is not available, then for a reciprocating compressor, the isentropic efficiency can be estimated from Equation 13.17 ... 

Calculate the work per pound of gas required to compress air from 70°F and 1 atm to 2000 psi with an 80% efficient compressor under the following conditions ... 

An engine operates on the open Brayton cycle and has a compression ratio of 8. Air, at a mass flow rate of 0.1 kg/sec, enters the engine at 27°C and 100 kPa. The amount of heat addition is IMJ/kg. Determine the efficiency, compressor power input, turbine power output, back-work ratio, and net power of the cycle. Show the cycle on a T-s... 

Sum of heat capacities of cold streams Sum of heat capacities of hot streams Efficiency, electric motors Polytropic efficiency, compressors and turbines Force... 

Gas turbine pressure ratio Gas turbine inlet temperature Turbine polytropic efficiency Compressor polytropic efficiency Recuperator effectiveness... 

A single-channel TSA system was developed for NASA COj collection and compression from the Martian atmosphere [196]. Accordingly, there was a need for a lightweight, highly efficient compressor. Based on the results of single-... 

Example 9.4. A 100 percent efficient compressor is required to compress air from 1 to 3 atm. The inlet temperature is 68°F. Calculate the work per pound-mole for an isothermal compressor and an adiabatic compressor. 

This example illustrates the fact that the effect of the. compressor inefficiency is to raise the outlet temperature of the compressor. One may look upon this compressor inefficiency as being a type of friction heating. The extra work above that which would have been required for a 100 percent efficient compressor goes to heat either the gas passing through the compressor or the surroundings. 

In the first part of this chapter, we started with a problem to find the compressor outlet temperature when given the compressor efficiency. Compressor basically used to move gases. In this chapter the user operated a compressor operation in HYSYS to model the compressing process. 

Refrigerators and freezers account for about 20% of the total electricity consumption of household appliances. For this reason the appliance industry is under pressure to improve the energy efficiency of their products to cope with the need to reduce carbon dioxide emissions, as recently mandated by the Kyoto Conference. This objective has to be achieved without penalising product performance. Several options to decrease the energy consumption are under evaluation, ranging from high efficiency compressors to the adoption of intelligent electronic devices [57, 58, 59]. 

Figure 17 Cooling efficiency = compressor capacity Cc/electrical power...

Use the most efficient compressor and the details of the same should be looked into. Cooling water requirements for the unit temperature and flow of cooling water required in m /hour. when the refrigeration unit is running with a water cooled condenser for the working fluid (e.g., ammonia/freon)... 

The dischai e temperature of a compressor can be calculated by Eq, (4) or Eq. (9), it is a fimetion of inl gas temperature, compression ratio, isentioplc exponent, and compressor efficiency. Compressor discharge temperature is sensitive to the value of isentroptc or polytropic exponent. This is true for all types of compressors. 

If the refrigerator in Problem 5.33 had been utilized as a liquefier, determine the liquid yield and the figure of merit for the system. Compare these results to those obtained for an ideal system (100% effective heat exchanger and 100% efficient compressor) operating under the same pressure and temperature conditions. 

These factors, which are component efficiencies, compressor pressure ratio, and turbine inlet temperature, are mainly determined by the design of the engine. 

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