Density and specific gravity of some common substances. Th movement cooling by the removal of heat the movement of heat from a place where it is notot a ted to a wanted to a place where it is unobjectionable. Larger is the irreversibility in a refrigeration cycle operating with a given refrigeration load between two fixed temperature levels, larger is the amount of work required to operate the cycle. This amounts to 40% of the energy supplied in the fuel. Heat rejection from the lower cycle to the upper cycle takes place in an adiabatic counterflow heat exchanger where. Diagram of a refrigeratorabove is a diagram of the mechanical components of a refrigerator. The suction line connects the evaporator or cooling coil to. The refrigeration cycle explained in plain english.
Refrigeration may be defined as a process of removing heat from a substance and pumping it to the surroundings. Carefully inspect the unit schematic and the cycle diagram. Atmospheric pressure is the pressure exerted on the earths surface by the weight of the air in the atmosphere above the earths surface. The area contained within the envelope is for a liquid vapour mixture.
It takes less energy to relocate heat than it does to create it. The pressureenthalpy diagram log ph diagram is a very useful tool for refrigerant technicians. The operating cycle of the plant can be plotted on ph diagram corresponding to suction and the discharge pressure of the system to calculate theoretical cop of the plant. The refrigeration system requires some means of connecting the basic major components evaporator, compressor, condenser, and metering device just as roads connect communities. Accumulation the process in which water pools in large bodies like oceans, seas and lakes. Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pumps and refrigerators. The first slide shows a picture that includes all processes in the water cycle. A heat pump is a mechanical system that allows for the transference of heat from one location the source at a lower temperature to another location the sink or heat sink at a higher temperature. The science behind refrigeration berg chilling systems inc.
Refrigeration fundamentals heatcraft worldwide refrigeration. The water cycle bundle contents thomas county schools. Fundamentals of refrigeration part 5 refrigerants refrigerants ph chart this diagram shows a simplified pressure enthalpy chart for a non specified refrigerant. Sep 10, 2016 the refrigeration cycle is a critical component of hvac systems and is governed by the principles of thermodynamics. Jan 19, 2012 this video is an animation of how the refrigeration cycle works, with each components function. This is often measured at the liquids boiling point. The compressor is driven by a heat engine with a thermal efficiency of 40%. Pressureenthalpy diagram for r 12 pressureenthalpy table for r 12 vapor compression refrigeration system p, t, h, and phase changes in a vapor compression refrigeration cycle 2. Heat removed from the engine in the cooling system is recovered. The objective of this experiment is to explore various properties of a refrigeration cycle using r11. Case1 the basics of refrigeration cycle ph diagram analysis. Ii the major 4 components it part i of the refrigeration cycle we explain the general idea of the cycle now we will go more in depth.
Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. Figure shows the components in the cycle and figure 14 shows the basic cycle on the ph diagram. The condenser of the plant is to be cooled by liquid water, which experiences a temperature rise of 8oc as it flows over the coils of the condenser. Ppt refrigeration cycles powerpoint presentation free. Ph diagram representation of a dry refrigeration cycle. Ideal basic refrigeration cycle the ideal basic refrigeration cycle consists of four components, connected by piping with refrigerant flowing through the system. Before we dive in, lets get an understanding of four key. The air is adiabatically compressed, passes through a cooler, and is adiabatically expanded in an expansion engine. If a single refrigeration cycle could be used for the overall temperature range, this would be represented by the cycle 1a7b1.
In the denseair cycle, the refrigerant air is drawn by a compressor from the space to be cooled. If an expander had been used the line from d to a would be a vertical line. Larger is the irreversibility in a refrigeration cycle operating with a given refrigeration load between two fixed temperature levels, larger is the. The compressed gas heats up as it is pressurized orange. Ql representsthe heat being lost from the freezer compartment when the heat is used as energy to power theevaporation. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. Heat rejection from the lower cycle to the upper cycle takes place in an adiabatic counterflow heat exchanger where both streams enter at about 0. Irreversibility includes pressure drops in lines and. It important to understand the basic refrigeration cycle, to comprehend what is going on within the air conditioner units, we cannot see it.
We want to design a vaporcompression refrigeration cycle to absorb heat from a cool environment and reject it to a warm environment. Zubair latif comsats institute of information technology, lahore 2. Figure 15 refrigeration cycle on the ph diagram take the structure image of this refrigeration cycle from figure 15, it. The above figure shows the objectives of refrigerators and heat pumps. Before we dive in, lets get an understanding of four key concepts.
The refrigeration cycle used in denseair refrigerating machines consists of two adiabatic and two isobaric processes. These components may be in difference shape, capacity and size, but it does the same thing. Students will be able to illustrate a labeled diagram of the water cycle. Illustration about very basic diagram of the refrigeration cycle found in air conditioning and heat pump systems. The brayton cycle is often plotted on a pressure volume diagram pv diagram and on a temperatureentropy diagram ts diagram brayton cycle ts. The boiling point of a liquid is affected by the pressure exerted on its surface. Study 35 terms plotting the refrigeration cycle flashcards.
Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. In any cycle application whether it is an air conditioner or. A i t f 200 250 212 100 sensible steam heat measurable temperature temperature above 212 f. Goals of lab to get acquainted with a vaporcompression refrigeration system to be able to use pressureenthalpy diagrams and. Earths water is always in motion, and the natural water cycle, also known as the hydrologic cycle, describes the continuous movement of water. The refrigeration cycle is a critical component of hvac systems and is governed by the principles of thermodynamics. Click the blue headings to jump to that part of the pdf. Figure 15 refrigeration cycle on the ph diagram take the structure image of this refrigeration cycle from figure 15, it becomes the ph diagram for engineering calculation as shown in figure 16. A cyclic process can be represented very clearly in the ts diagram.
The primary difference is in the manner in which heat is utilized. Introduction a major application area of thermodynamics is refrigeration, which is the transfer of heat from a lower temperature region to a higher temperature one. Most of the differences between the ideal and the actual cycles are because of the irreversibilities in various components which are. This is the amount of heat required to turn a liquid into a gas. It also includes the process of maintaining and reducing the temperature of a body below the general temperature of its surroundings. Understanding the basic refrigeration cycle diagram also helps us to find subcooled, superheat and to troubleshoot refrigeration processes much easier. The refrigeration cycles can also be represented in a ph diagram. In practice, the working fluid of the lower cycle is at a higher. The measurement of actual cop, which is the ratio of actual cooling effect produced to the actual power consumption, is difficult under practical conditions. The arrows should show evaporation including transpiration. Process schematic diagram for refrigeration system the refrigeration unit circulates the refrigerant r4a. That noise is the sound of highpressure liquid refrigerant flowing through the expansion valve. A heat pump uses a vapour compression cycle with refrigerant 12.
A heat pump is a mechanical system that allows for. Most of the time, heat pumps used for heating are considered under the refrigeration heading, since the. Heat flows in direction of read urdu novels pdf decreasing temperature, i. The specific gravity of any substance is the ratio of weight of a given volume of the substance to the weight of the same.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Ppt refrigeration cycles powerpoint presentation free to. Subsequent slides discuss each process individually. The heat pump cycle uses an ideal cycle with an evaporator at 5oc and a condenser. Gases give off heat when changed from gas to liquid. The region to the left of the envelope represents liquid in a subcooled condition. Tubing or lines make the system complete so that the refrigerant will not leak out into the atmosphere. The attached figure shows schematically the refrigeration unit located in the heat transfer lab. Remember refrigeration cycle diagram will always have the same basic components compressor, condenser, expansion device, evaporator, and refrigerant tube. The design is to be based upon the ideal vaporcompression refrigeration cycle, with four components. The two cycles are connected through the heat exchanger in the middle, which serves as. Yeah, it seems complicated at first, but it will be easier to understand once i have explained the refrigeration cycle diagram section by section. The purpose of a refrigerator is the removal of heat, called the cooling load, from a lowtemperature medium.
Refrigeration cycle it is a well known fact that heat flows in the direction of decreasing temperature, i. The cold ammonia gas is sucked up by the compressor, and the cycle repeats. The coils on the back of the refrigerator let the hot ammonia gas. If we understand how the refrigeration cycle works, well understand how any air conditioner works.
Rev pages chapter 9 refrigerants, refrigeration cycles, and. This cogitation is to base on idea simple cycle with no losses. Draw arrows in the diagram below to indicate where water moves through the water cycle. Most of the differences between the ideal and the actual cycles are because of the. Water continually cycles from the earth to the atmosphere and back. This video is an animation of how the refrigeration cycle works, with each components function. Liquids absorb heat when changed from liquid to gas. First, an explanation of how the diagram is built up is given, and then its use is describ ed. Refrigeration fundamentals 2175 west park place blvd. Refrigeration cycle article about refrigeration cycle by. Here is a diagram of the natural water cycle, with the words removed.
523 447 113 1125 896 920 732 17 1190 125 596 1062 943 885 836 1008 1029 350 1540 846 799 211 194 1230 371 762 1198 798 449 1458 317 1015 145 350 1174 948