Vapor Compression Cycle
Vapor Compression Cycle - Related Videos
01:18
Vaporization
0 Views •
2019
The physical form of a substance changes by changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. For vaporization to occur, kinetic energy must be greater than the intermolecular forces that keep molecules bonded. The amount of energy needed to vaporize a quantity of liquid at a given pressure and a constant temperature is called the heat of vaporization. When...
02:34
Vapor Pressure
0 Views •
2020
When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules move randomly about, they will occasionally collide with the surface of the condensed phase, and in some cases, these collisions will result in the molecules re-entering the condensed phase. The change from the gas phase to the liquid is called condensation. When the rate of condensation becomes equal to the rate of vaporization, neither the amount of the liquid nor the amount of the vapor...
11:32
Vapor-liquid Equilibrium
0 Views •
2023
Source: Michael G. Benton and Kerry M. Dooley, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Vapor-liquid equilibrium is paramount in engineering applications such as distillation, environmental modeling, and general process design. Understanding the interactions of components in a mixture is very important in designing, operating and analyzing such separators. The activity coefficient is an excellent tool for relating molecular interactions to mixture...
03:28
Vapor Pressure Lowering
0 Views •
2020
The equilibrium vapor pressure of a liquid is the pressure exerted by its gaseous phase when vaporization and condensation are occurring at equal rates: Dissolving a nonvolatile substance in volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be explained by considering the effect of added solute molecules on the liquid's vaporization and condensation processes. To vaporize, solvent molecules must be present at the surface of the solution. The presence of...
13:31
A Neonatal Mouse Spinal Cord Compression Injury Model
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Cited by 4 •
2016
This article describes a method for generating a reproducible spinal cord compression injury (SCI) in the neonatal mouse. The model provides an advantageous platform for studying mechanisms of adaptive plasticity that underlie spontaneous functional recovery.
FAQs
The compressor supplies the mechanical work that drives the cycle and changes the refrigerant’s pressure and temperature before heat rejection occurs. This preparation enables the refrigerant to proceed to the condenser, where it can reject heat and liquefy. Engineers therefore examine compressor behavior when assessing how effectively a system converts mechanical input into controlled heat transfer.
The refrigerant changes phase at two important points. In the condenser, it rejects heat while liquefying; in the evaporator, it absorbs heat while vaporizing. These phase changes connect the system’s heat-rejection and heat-absorption functions, allowing engineers to analyze how the refrigerant moves heat between a cooler region and a warmer one.
The expansion device lowers the refrigerant’s pressure after the condenser. This pressure change prepares the refrigerant for the evaporator, where it can absorb heat and vaporize. Its position is essential because it links heat rejection to heat absorption and helps maintain the repeated sequence required for continuous operation.
Engineers evaluate how the cycle and its components perform when operating conditions change. They consider the compressor, condenser, expansion device, and evaporator as an interacting system rather than isolated parts. This analysis helps identify effects on controlled heat transfer and supports equipment design, performance evaluation, and efforts to improve energy efficiency.
The cycle provides the operating basis for most refrigeration, air-conditioning, and heat-pump systems. Its use extends across equipment designed either to provide cooling or to support controlled heating through heat transfer. In engineering practice, understanding the cycle helps explain how these systems operate and provides a foundation for designing and evaluating their performance.
Refrigerant selection is one factor engineers consider when designing vapor compression equipment and improving energy efficiency. The chosen refrigerant circulates through every major component, undergoing pressure changes and phase changes that enable heat transfer. Engineers therefore relate refrigerant choice to the intended system design, operating conditions, and performance evaluation rather than treating it as an isolated material decision.