Category: Advance Concept Mechanical Eng

Research on use of refrigerant is continuously going on due to adverse effect on depletion of ozone layer. The production of many refrigerants will soon end, including R-22 and R-123 in accordance to the requirements of the Montreal Protocol. Suppliers currently offer a range of refrigerants based on chiller type, capacity, and regulatory requirements. The refrigerants…

The absorption cycle is a process by which refrigeration effect is produced through the use of two fluids and some quantity of heat input, rather than electrical input as in the more familiar vapour compression cycle. Both vapour compression and absorption refrigeration cycles accomplish the removal of heat through the evaporation of a refrigerant at…

Advantages Disadvantages

Heat extracted from system (i.e., absorbed in absorber) = Heat transfer during the process, A−B = refrigerating effect. Heat rejected from condenser

Advantages Disadvantages Example 8.1: Carnot refrigeration cycle absorbs heat at 250 K and rejects heat at 300 K. Solution: Given: T1 = 250 K; T2 = 300 K Example 8.2: The capacity of a refrigerator is 150 TR when working between − 5 and 20°C. Determine the mass of ice produced per day from water at 20°C. Also find the power…

In this system, air is taken into the compressor from atmosphere and compressed and then the hot compressed air is cooled in heat exchanger up to the atmospheric temperature. The cooled air is then expanded in an expander. The temperature of the air coming out from the expander is below the atmospheric temperature due to…

Reversed Carnot cycle Reversed Carnot cycle is shown in Figure 8.2. It consists of the following processes. Figure 8.2 P−V and T−S Diagrams for Reversed Carnot Cycle Process a–b: Absorption of heat by the working fluid from refrigerator at constant low temperature TL during isothermal expansion. Process b–c: Isentropic compression of the working fluid with the aid of external work. The temperature of the fluid…

Broadly, the refrigeration systems can be categorized as

Within the refrigeration system, the expansion valve is located at the end of the liquid line, before the evaporator. The high-pressure liquid reaches the expansion valve, having come from the condenser. The valve then reduces the pressure of the refrigerant as it passes through the orifice, which is located inside the valve. On reducing the…