Compressor - Compressor The compressor performs 2 functions...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Compressor: The compressor performs 2 functions. It compresses the gas and it moves the refrigerant around the loop so it can perform its function over and over again. We want to compress it because that is the first step in forcing the gas to go back into a liquid form. This compression process unfortunately adds some more heat to the gas but at least this process is also conveniently named; The Heat of Compression . The reciprocating compressor is similar to an automobile engine. A piston is driven by a motor to "suck in" and compress the refrigerant in a cylinder. As the piston moves down into the cylinder (increasing the volume of the cylinder), it "sucks" the refrigerant from the evaporator. The intake valve closes when the refrigerant pressure inside the cylinder reaches that of the pressure in the evaporator. When the piston hits the point of maximum downward displacement, it compresses the refrigerant on the upstroke. The refrigerant is pushed through the exhaust valve into the condenser. Both the intake and exhaust valves are designed so that the flow of the refrigerant only travels in one direction through the system. Types of Compressors: The main types of compressors include the following; Positive Displacement Compressor Piston Compressor Screw Compressor Vane Compressor Centrifugal Compressor
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Refrigeration Cycle: The refrigeration cycle or heat pump cycle is the model describing the transfer of heat from regions of lower temperature to regions of higher temperature. It defines the operating principles behind refrigerators, air conditioners, heaters, and other "heat pumping" devices. This diagram presents a visual overview of the refrigeration cycle: The letters A-D indicate the different system components. The numbers 1-5 indicate the different physical states of the refrigerant fluid as it moves through the system. State 1 is the state after the refrigerant passes through an evaporator (D), where warm air heats the fluid and converts it completely to vapor. State 2 is the state after the fluid passes through a compressor (A) which increases the fluid's pressure and temperature up to superheated levels. States 3 and 4 are when the fluid passes through an evaporator (B), which transfers heat to the ambient and condenses the fluid to liquid.
Image of page 2
State 5 is the state after the fluid passes through an expansion valve or metering device (C), which lowers the pressure of the fluid. This cools the fluid and subsequently turns the liquid into a liquid/vapor mixture. The diagram below depicts temperature-entropy above drawn refrigeration cycle: The following diagram shows pressure-entropy of above drawn refrigeration cycle:
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Description of Types of Compressors: There are a number of different types of compressors used for refrigeration and air conditioning. Positive displacement compressors have chambers which decrease in volume during compression, while non-positive displacement compressors have fixed- volume chambers. Beyond this distinction,
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern