PDF Publication Title:
Text from PDF Page: 067
Heat Pumps for Heating and Cooling 5.1.2. Open compressors In an open compressor, the motor is outside the compressor’s casing and the two are connected by a work transferring shaft. The motor does not come into direct contact with the refrigerant, making the environment of the motor friendlier than it was in the case of a hermetic compressor. Maintenance of an open compressor is relatively easy as the motor can be attended independently. The drawback is that the compressor is little noisy and the refrigerant is vulnerable to leakage. 5.1.3. Semi-hermetic compressor A semi-hermetic compressor is like a hermitic compressor in that the motor is placed inside the casing. However, the casing is bolted, not welded, shut. The bolted casing can be opened for maintenance reasons and when properly bolted the characteristics of a semi-hermitic compressor resemble that of a hermetic compressor. 5.2. Types of Compressors Compressors can also be divided into two groups: dynamic or positive displacement compressors. A positive displacement compressor causes the pressure of a fluid to increase by decreasing its volume. A dynamic compressor on the other hand compresses a fluid by giving it kinetic energy and the pressure rises in accordance with the Bernoulli’s principle. The compressor may be a reciprocating type, rotary type, screw type, or centrifugal type; depending on the capacity of the unit, and whatever design advantages the engineers might have been trying to optimize for the unit. 5.2.1. Reciprocating compressor The reciprocating compressor is a positive displacement compressor. It is made out of a piston, a compression chamber and pressure sensitive valves that allow the refrigerant to flow in and out of the compression chamber. It has the advantage of being a simple and well-known technology with high efficiencies. It can operate at high-pressure ratios and is used in versatile applications. Its disadvantages are sensitivity towards liquid slugging and dirt particles as well as the pulsation nature of the compression process and a large number of moving parts. 5.2.2. Screw compressor A screw compressor is also a positive displacement compressor. It can have one or two screws that compress the refrigerant as it moves down the spiral. The advantages are the continuous flow of refrigerant into the compressor allowing a 66PDF Image | Heat Pumps for Heating and Cooling
PDF Search Title:
Heat Pumps for Heating and CoolingOriginal File Name Searched:
heat-pumps-for-cooling-r1.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |