Gas Refrigerators

The Philips refrigerator is based on the Stirling cycle. The basic components of the refrigerator are a displacer, a regenerator, and a piston all enclosed in a cylinder. The refrigeration cycle involves four process steps (see Fig. 4.25)  

Process 1-2 is an isothermal compression step wherein heat is released to the surroundings by means of cooling water. 

In process 2-3, the displacer is moved toward the piston, forcing the compressed gas through the regenerator where it is cooled. The energy removed is stored in the regenerator. 

Process 3-4 is an isothermal expansion step involving both displacer and piston in which heat is absorbed at the low temperature. 

In process 4-1, the displacer moves away from the piston once again forcing the gas through the regenerator. The energy previously stored in the regenerator is now used to warm the gas. 

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Used to present the heat and material balance of a process. This may be in broad block form with specific key points delineated, or in more detailed form identifying essentially every flow, temperature and pressure for each basic piece of process equipment or processing step. This may and usually does include auxiliary services to the process, such as steam, water, air, fuel gas, refrigeration, circulating oil, etc. This type of sheet is not necessarily distributed to the same groups as would receive and need the piping flowsheet described next, because it may contain detailed confidential process data. 

Storage In air, in vacuum, in inert gas, refrigerated, frozen storage, transport... 

Absorption Air-Conditioning Brayton Gas Refrigeration Cycle Stirling Refrigeration Cycle Ericsson Cycle Liquefaction of Gases Nonazeotropic Mixture Refrigeration Cycle Design Examples Summary... 

The basic gas Brayton refrigeration cycle is the reversed Brayton gas power cycle. The components of the basic gas refrigeration cycle include a compressor, a cooler, a turbine, and a heater, as shown in Fig. 6.26. 

Applying the first and second laws of thermodynamics of the open system to each of the four processes of the basic gas refrigeration yields ... 

The desirable energy output of the basic gas refrigeration cycle is the heat added to the heater (or heat removed from the inner space of the refrigerator). The energy input to the cycle is the net work required. Thus, the coefficient of performance (COP) of the cycle is... 

A combined split-shaft gas turbine power plant and gas refrigeration system to be used in an airplane, as illustrated in Fig. 6.41a, has been designed by a junior engineer. 

During the cruise condition, the split-shaft gas turbine power plant required to produce 240 kW and 10% of the compressed air, is used in the gas refrigeration system, which is required to remove 7kW from the cabin. 

Figure 6.41a Combined gas turbine power plant and gas refrigeration system design. 

The Brayton gas refrigeration cycle is a reversed Brayton gas power cycle. 

Carbon dioxide is a gas at room temperature. Below -78°C it is a solid and is commonly referred to as dry ice. At that temperature it sublimes and changes directly from a solid to a vapor. Because of this unique property, as well as its non-combustible nature, it is a common refrigerant and inert blanket. Table 3.4 shows the uses of carbon dioxide in all its forms liquid, solid, and gas. Refrigeration using dry ice is especially important in the food industry. Beverage carbonation for soft drinks is a very big application. In oil and gas recovery carbon dioxide competes with nitrogen as an inert atmosphere for oil wells. 

Methane, refrigerated liquid (cryogenic liquid) or natural gas, refrigerated liquid (cryogenic liquid - with high methane content) 1972... 

For low-temperature operation, liquid gas refrigerants contained in Dewars surrounding the reactor effectively maintain the sample temperature, but it is critical that the level be maintained constant for precise adsorption studies. Temperatures intermediate between the boiling or critical temperatures of nitrogen can be maintained by controlled pumping of the volume over the refrigerant gas, either as such, or... 

The author gratefully thanks the Public Archives of Canada for permission to publish this article and the Dupont Co., Wilmington, Del., and Dupont of Canada, Ltd., Kingston, Ontario, for guidance in handling liquified gas refrigerants. 

SYNS FIRE DAiMP MARSH GAS METHANE, compressed (UN 1971) QDOT) METHANE, refrigerated liquid (crj ogenic liquid) (UN 1972) OT) METHYL HYDRIDE NATURAL GAS, compressed (with high methane content) (UN 1971) (DOT) NATURAL GAS, refrigerated liquid (cryogenic liquid) (with high methane content) (UN 1972) (DOT)... 

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