Refrigeration System Components and Ammonia as Refrigerant Quiz

Heating Ammonia Solution

• When a weak solution of ammonia in water is heated, it releases ammonia gas.

Aqua-Ammonia Absorption Refrigeration System

• In the absorber, the strong and weak solutions are separated and recombined to maintain the refrigeration cycle.

Analyzer-Rectifier Advantage

• Using an analyzer-rectifier in an aqua-ammonia absorption system provides a higher concentration of ammonia, resulting in a more efficient refrigeration process.

Saturation Temperature Comparison

• The saturation temperature of ammonia is lower than that of water at the same pressure.

Energy Expenditure in Vapor Absorption Refrigeration

• Thermal energy needs to be expended in a vapor absorption refrigeration system.

Air-Side Coefficient Equation

• The correct equation to compute the air-side coefficient (hf) in a refrigeration system is hf = (T_r - T_a) / (T_r - T_w), where T_r is the refrigerant temperature, T_a is the ambient temperature, and T_w is the wall temperature.

Metal Tubing Material

• Copper is commonly used for the metal tubing of containers in refrigeration systems.

Frost Detriment

• Frost is detrimental to the operation of refrigeration systems because it reduces heat transfer and increases pressure drop.

Constant Temperature Portion

• When the refrigerant condenses at a constant pressure, its temperature is constant in the subcooling portion of the condenser.

Cold Water Flow

• In a water-type condenser's double pipe setup, the cold water flows through the inner pipe.

Condenser Surface Area Comparison

• The surface area of natural convection type condensers is generally larger than that of forced convection type condensers for the same capacity.

Hermetic Reciprocating Compressor

• When there is an increase in the evaporating temperature in a hermetic reciprocating compressor, the refrigerant flow rate increases.

Direct-Expansion Inner Fin Chiller

• A decrease in the water entering temperature in a direct-expansion inner fin chiller increases the refrigerating capacity.
• An increase in the evaporating temperature in a direct-expansion inner fin chiller decreases the refrigerating capacity.
• An increase in water flow rate in a direct-expansion inner fin chiller increases the refrigerating capacity.

Refrigeration Capacity and Ambient Temperature

• Refrigeration capacity decreases with high ambient temperature.
• At a certain condensing temperature, the heat rejection rate increases with high ambient temperature.

Rectifier and Analyzer Components

• The purpose of using the rectifier and analyzer components in the aqua-ammonia system is to separate and recombine the strong and weak solutions.

Pipe Material for Ammonia

• When using ammonia as a refrigerant fluid, the pipes should be made from steel or stainless steel to resist corrosion.

COP Comparison

• The Coefficient of Performance (COP) of a vapor absorption system is generally lower than that of a vapor compression system.

Heat Addition in Absorption System

• Heat is added to the solution by the generator component in an absorption system.

Work Input Requirement

• The work input requirement for an ammonia absorption refrigeration cycle is low due to the low pressure ratio.

Cooling Water Requirement

• The absorber and condenser equipment in an ammonia absorption plant require cooling water.

Temperature Ranges

• Heating, cooling, and refrigeration take place at temperatures of 80-120°C, 20-40°C, and -10 to 10°C, respectively, in a vapor absorption refrigeration system.

Common Type of Absorption Refrigeration System

• The most common type of absorption refrigeration system used in industrial applications is based on the aqua-ammonia system.

Fittings Material in Li-Br Water System

• Fittings in a Li-Br water absorption refrigeration system are commonly made of stainless steel or bronze.

Refrigerants Used

• Ammonia and lithium bromide (Li-Br) are used as refrigerants in aqua ammonia and Li-Br water refrigeration systems, respectively.