Notes on compression refrigeration compression refrigeration is achieved using a working fluid called refrigerant. Refrigeration cycle tutorial university of oklahoma. The illustration above is a consumers understanding of refrigeration. Some basic refrigeration cycles are discussed here through different diagrams. An analysis would start at the evaporator where cold liquid is changed into a gas as it picks up heat from room air passing over the coil.
The refrigeration basic principle is that with the aid of a heat pump, the refrigerant is being compressed to the condenser and capillary tube thus increasing its temperature 5060c and pressure 750 kpa in the refrigerator being cooled down by the condensing unit to 32c depending the existing ambient temperature. Such systems tend to be more complex primarily due to the volatility of the absorbent which requires the use. Water may instead be used as the absorbent and ammonia as the refrigerant. This is often measured at the liquids boiling point. There are two laws that are significant to understand the basic refrigeration cycle and air conditioning. The highest levels of efficiency in these systems are achieved through a. The problem is how to convey heat from an area of a given temperature to an area of higher temperature. Heat and refrigeration principles learning objective. However, first lets understand air conditioning theory, the basic principle, types of heat, how heat transfers and well discuss how the basic refrigeration cycle diagram works. Feb 06, 2017 the first point to understand about refrigeration theory is that heat is energy, and it can be made to move. Wet refrigeration cycle the expander has been substituted by a throttling valve. However, first lets understand air conditioning theory, the basic principle, types of heat, how heat transfers and i will show you how the basic refrigeration cycle diagram works.
Case1 the basics of refrigeration cycle ph diagram analysis. It is intended to cover only the fundamentals of refrigeration theory and practice. Air conditioning theory there are two laws that are significant to understand the basic refrigeration cycle and air conditioning. The capacity is expressed as ton of refrigeration which is equivalent to 12600 kjh 3000 kcalh heat removed by the plant from the evaporator. Back to basics whether youre new to refrigeration or just want to brush up on your basics, the following information may be useful. As an example, a typical refrigeration circuit of an air conditioner, can, by tracing the refrigerant flow, be classified as a heat pump. The fridge gate method is a theoretical application of using a single logic gate to drive a refrigerator in the most energy. Heat has its own laws, called the laws of thermodynamics. Rev pages chapter 9 refrigerants, refrigeration cycles. In old refrigerators, this gas was chloroflourocarbon, or cfc, but this has harmful effects on people, so refrigerators not contain hfc4a. Industrial refrigeration system basics, in this video well be looking at how ammonia refrigeration systems work, starting at the basics to. Sep 10, 2016 the refrigeration cycle is a critical component of hvac systems and is governed by the principles of thermodynamics. Vapourcompression refrigeration or vaporcompression refrigeration system vcrs, in which. In this article and the next, we look at components.
Refrigeration is a process that removes heat from a space, substance, or system to lower andor. Nov 29, 2012 refrigeration andairconditioningnotes 1. It is 98 pages, reprinted from a military training manual, in pdf format. Just a short video explaining the basics of how most refrigeration systems operate. Basic concepts in refrigeration free download as powerpoint presentation.
This is the temperature at which all molecular motion stops and the. This interactive multimedia training cdrom on refrigeration theory covers the fundamental principles of refrigeration in airconditioning. Jun 02, 2005 this is another in a series of articles addressing advanced basics in the understanding of the refrigeration cycle. Balamugundansenior lecturerpanimalar engg college refrigeration and air conditioningrefrigeration. Industrial refrigeration system basics ammonia refrigeration. Learning about refrigeration is a never ending process and well understood fundamentals make learning more advanced concepts much easier. The refrigeration cycles can also be represented in a ph diagram.
The general rule for rating refrigeration systems excepting for co. This is the amount of heat required to turn a liquid into a gas. Efficient up to 60% of carnots theoretical limit as evaluated in ashrae. Also covered in this chapter are the methods used for installing, maintaining, and repairing refrigeration equipment, including domestic refrigerators and freezers. Having seen all the recent fridge threads happening i figured a little school time might be in order to help those who are a bit befuddled by the electrorefridgery trickery that happens inside all fridges and air conditioning systems, from your house aircon to the local ice rink or supermarket, not just our trusty engelswaecos etc. Download refrigeration and air conditioning ebook by p. Ph diagram representation of a dry refrigeration cycle. In the past, this was done by collecting ice in the winter and using its specific heat to cool as the ice melted.
In an air or gas expansion system, air or gas is compressed to a high pressure by mechanical energy. An overview of the basic refrigeration cycle youtube. Refrigeration fundamentals heatcraft worldwide refrigeration. Basic cryogenic processes joulethomoson process, brayton process as well as claude process are described and compared. Industrial refrigeration best practices guide 1 chapter 1. Explain the basics of heat theory and the basic principles of refrigeration. When that heat is allowed to move back into the ice, the ice will melt. Heres your chance to see how much of the material in this book you have grasped.
So refrigeration cycle should be known to understand the refrigeration system. Refrigeration basic principle refrigeration evaporators. Download free sample and get upto 56% off on mrprental. Working of a refrigerator and refrigeration principle behind it is explained with help of animation in a logical way in this video.
Apr 28, 2017 refrigeration systems have gas installed in a series of tubes. Hfc4a is the sole gas used as a coolant in refrigeration systems. This manual is designed to fill a need which exists for a concise, elementary text to aid servicemen, salesman, students, and others interested in refrigeration. Refrigeration and air conditioning training course principles. To read more about basic refrigeration theory, you might be interested in reading our free introduction to air conditioning and refrigeration online e book. When 1 pound of ice melts, it absorbs 144 btu, as latent energy. This video gives a detailed and logical introduction to the workings of. On completion of this course, students should be able to 1. Introduction chapter 1 introduction courtesy of frick background this guide identifies and discusses best practices for making industrial refrigeration systems both energyefficient and productive. The first point to understand about refrigeration theory is that heat is energy, and it can be made to move. There is no time limit for this test but it is not an.
However, they may expect you to have a much greater indepth understanding of refrigeration to help them solve their cooling needs. A refrigerant is typically a fluid that evaporates at very low pressure and therefore temperature. This article gives details about the functions of the compressor, discharge line, and condenser. Before we dive in, lets get an understanding of four key concepts. Refrigeration cycle refrigeration is the transfer of heat from a lower temperature region to a higher temperature region refrigeration cycle is the vaporcompression refrigeration cycle, where the refrigerant is vaporized and condenses alternately and is compressed in the vapor phase. Refrigeration heat transfer devices such as air cooled condensers and evaporators are often made out of copper pipes with aluminum fins and further enhanced with fans to force air through the fins. Contents this brochure assists you in selecting the right instruments. Compressor basic refrigeration cycle evaporator condenser receiver.
Basic refrigeration cycle a centrifugal chiller utilizes the vapor compression cycle to chill water and reject this heat collected from the chilled water plus the heat from the compressor to a water loop cooled by a cooling tower. Mathematical model of a vapour absorption refrigeration unit the absorbentrefrigerant part need not necessarily be lithium bromide and water. This chapter gives an overview of the principles of low temperature refrigeration and the thermodynamics behind it. The danfoss product range for the refrigeration and air. Here, wika is the competent partner for measuring instruments for pressure, temperature and calibration in all parts of refrigeration plants. Aug 27, 2017 brazing the ac system line set while purging with nitrogen using the flow guard duration. Online practice test on refrigeration and airconditioning.
The online version of refrigeration and airconditioning by g. Heat transfer fluid pressure bar approx evaporation temp c water 1 100 r4a 1 26. Refrigeration technology is commonly used in domestic and industrial applications. Because the temperature of air or gas drops during expansion, a refrigeration effect is produced. Industrial refrigeration and cooling invest northern ireland. The total refrigeration requirement of a dairy plant can be estimated by calculating the cooling load of various operations and based on the hourly refrigeration load requirement. If an expander had been used the line from d to a would be a vertical line. Refrigeration cycle is the basis of all refrigeration systems. Metering device we will now take a closer look at the individual components of the system. The 3way valve in this example is capable of opening to either one port only or to both ports. It can be defined as the process of transferring heat from a low temperature regionto a high temperature region. Refrigeration and airconditioning is the subject which deals with the techniques to control the environments of the living and non living subjects and thus provide them comforts to enable them to perform better and have longer lives.
Your customers may not need to go beyond this simple understanding of refrigeration. Refrigeration and air conditioning training course principles of refrigeration 32 hours, 32 nate cehs, 3. Mechanical refrigeration works by changing the the majority of heat is removed from the the majority of the works by removedchanging the absorbed heat is state of the refrigerant. If enough heat is removed from a glass of water, the water will freeze to ice.
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