Compression and absorption type refrigerators and freezers. This is the series of articles that describe what is refrigeration, and methods of refrigeration like ice refrigeration, dry ice refrigeration classified as noncyclic refrigeration processes. Using multimedia in learning can also help to promote deeper learning and has positive impact in creating a learnercentred teaching environment. If the condenser is as much as 8 or 10 ft above the compressor, provisions should be made to trap the oil and. When and why the refrigeration evaporator is a container that provides room for the evaporating refrigerant. This term will be used in this study to refer to the teaching using chalk and board for teachers. It has applications in both air conditioning and commercial and industrial refrigeration. Refrigeration is a process that removes heat from a space, substance, or system to lower andor maintain its temperature below the ambient temperature.
Various control methods for refrigeration systems were developed. Methods of refrigeration can be classified as noncyclic, cyclic, thermoelectric and magnetic. Common methods of defrost air defrost offtime hot gas defrost electric defrost. Otherwise, with a dense population, only a quarter of the plate area is streaked. Conventional cooking methods, professional cooking ch. There are two methods of noncyclic refrigeration process as described below. The temperature of ice is considered to be 0 degree celsius hence it can be. To cook foods by surrounding them with hot, dry air, usually in an oven. Methods of refrigeration can be classified as noncyclic, cyclic and nonconventional methods. It has already been proven that incorporation of pcm with refrigeration systems improves the energy efficiency as. The nozzles are of converging or diverging or convergingdiverging type as per the design. Conventional ice rink refrigeration versus geothermal ice rink systems by mike bryson, march 2007 conventional ice rink refrigeration systems are designed solely to make ice. Transforming conventional teaching classroom to learner. These methods are used for smallscale refrigeration such as in laboratories and portable coolers, or in workshops.
G1816 food preservation, safety, and shelf life extension food processing for entrepreneurs series durward a. Magnetic refrigeration magnetic refrigeration is a method of refrigeration based on the magnetocaloric effect. The aim of all food preservation methods is to slow down processes that cause deterioration of quality and wholesomeness. Syed shahrukh madni introduction thermoacoustic liquefiers convert gas to liquid using sound waves.
Another method of equalizing hot gas and receiver pressures and crankcase oil. All methods require sufficient refrigeration capacity to reduce the temperature of the produce within the required time plus the ability to remove the normal heat gain in the facility. Refrigeration is a process that removes heat from a space, substance, or system to lower andor. The above figure shows the objectives of refrigerators and heat pumps. The evaporator transfers heat into the refrigerant.
It also describes cyclic methods of refrigeration like vapor compression cycle, vapor absorption cycle etc. Refrigeration, the process of removing heat from an enclosed space or from a substance for the purpose of lowering the temperature. Energy in the form of heat is removed from a lowtemperature reservoir and transferred to a hightemperature reservoir. Learning objective details of method of refrigeration conventional methods non conventional method concept of heat pump, refrigerator 3. Introduce aspects of various natural refrigeration methods, namely. What is conventional methods of teaching igi global. Another suggested method for hot gas lines, when paralleling two compressors, is shown in figure 66f03a. The most widely used methods are applications of lindes and claudes cycle, however over time various variations have brought about improvements in yield and efficiency. In the noncyclic method of refrigeration there is no thermodynamic cycle followed for creating the cooling effect. Rather the teacher uses other methods such as demonstration using examples, lecture methods, question answer methods among others. In simple vapor compression system we use refrigerant for getting refrigerating effect. The stal rotatune system is ideal for all small and mediumsize installations where the.
Define refrigeration and air conditioning section 1. This effect, discovered in 1881, is defined as the response of a solid to an applied magnetic field which is apparent as a change in its temperature. However, such a conventional technique to cope with. Study on refrigeration system designed for low temperature ijsrp. Book download link provided by engineering study material esm. Iii testing methods in food microbiology tibor deak encyclopedia of life support systems eolss from the edge of the petri dish toward the center. A well designed system with an appropriate control system, sized for the application, will do a good job of. What are the non conventional methods of refrigeration system. Cookchill is a simple, controlled system of food preparation designed to provide more flexibility in food service. Many magnetic refrigeration prototypes with different designs and software models have been built in different parts of the world. Screw compressor capacity regulated by stepless speed control. Refrigeration is the process of removing thermal energy or heat from a low temperature reservoir and transferring it to a high temperature reservoir requiring the input of energy.
A conventional cold store is unsuited for this operation because. Technological and economical analysis of application of non conventional heating and cooling systems. Conventional ice rink refrigeration versus geothermal ice. By replacing conventional methods of capacity control by stepless speed control, an optimum volume ratio can be obtained without energy losses, even at part load. As the name suggests, these types of systems transfer heat by mechanically compressing refrigerant into a lowpressure, cold liquid and expanding it into a highpressure, hot gas. This ppt provide information about the conventional methods of animal vaccine productionit is somewhat differ from my earlier ppt of vaccine production techn slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The temperature of ice is considered to be 0 degree celsius hence it can be used to maintain the temperatures of about 5 to 10 degree celsius. Now in the study of refrigeration we will be observing various methods of cooling the objects and maintaining the temperature of bodies at values lower than surrounding temperature. Refrigeration applications are equipment that transfers heat from the product or enclosure refrigerated cabinet or room to the colder refrigerant.
Industrial refrigeration is often confused with commercial refrigeration because the division between these two areas is not clearly defined. An introduction thermoelectric cooling uses the peltier effect to create a heat flux between the junctions of two different types of materials. Different methods of refrigeration are dry ice refrigeration, evaporative, thermoelectric, steam jet, liquid gas and vortex tube system of refrigeration. Cook on a spit infront of an open fire may also be considered roasting. The most widely used refrigeration cycle method is mechanical compression. In the industrialized nations and affluent regions in the developing world, refrigeration is chiefly used to store foodstuffs at low temperatures, thus inhibiting the. Vortex tube refrigeration it consists of nozzle, diaphragm, valve, hotair side, coldair side. In this paper, the authors try to shed light on the magnetic refrigeration and show its effectiveness compared with conventional refrigeration methods. The aims of preservation methods are to inhibit the microbial spoilage and also to minimize the oxidation and enzymatic spoilage.
Compressor basic refrigeration cycle evaporator condenser receiver expansion device. A fluid or refrigerant repeatedly circulating through the refrigeration systems components accomplishes the heat transfers. Applications of refrigeration and air conditioning. Conventional systems rely on vapor compressors to create the pressure difference that causes.
The refrigerant receives heat by conduction through the walls of the container. Improperly stored fruits and vegetables lose nutrition value over a period of time. Conventional methods of nondestructive testing ndt are used in a variety of industry sectors, including everything from oil and gas, renewables, rail, construction and fabrication, shipbuilding, steel production, biochemical through to theme parks and fairgrounds. This effect is commonly used in camping and portable coolers and for cooling electronic components and small instruments. Refrigeration for food preservation fruits and vegetables are perishable commodities. Improve the cop of vapor compression cycle with change in.
If not stored at recommended temperatures, they rot in a short time by chemical reactions, bacterial attack, or water loss. As a general rule, industrial applications are larger in size than commercial applications and have the distinguishing feature of requiring an attendant on duty, usually a licensed operating engineer. According to american society of heating, refrigeration and airconditioning engineers ashare refrigeration is the science of providing and maintaining. Barrett i nterest in the nutritional value of fruits and vegetables has been increasing, in part because of recent findings on the high level of obesity and other dietrelated. In other words, refrigeration is artificial humanmade cooling. Fundamentals of hvac controls course content fundamentals of hvac controls the application of heating, ventilating, and airconditioning hvac controls starts with an understanding of the building and the use of the spaces to be conditioned and controlled. In this method the ordinary ice is used for keeping the space at temperature below the surrounding temperature. Stratton, manager, laboratory testing operations a host of food preservation options are available. Preservation methods depend upon the food and shelf life extension required. Current meat preservation methods are broadly categorized into three methods a controlling temperature b controlling water activity c use of chemical or biopreservatives 12. The four types of refrigeration systems you need to know. Refrigeration cycles the vapor compression refrigeration cycle is a common method for transferring heat from a low temperature to a high temperature. Onoff control method is the most used conventional technique to control rss 6.
In simple vapor compression system we use refrigerant for getting r. Maximizing the nutritional value of fruits and vegetables. What are the non conventional methods of refrigeration. Nonconventional heating and refrigeration systems energy. Index terms flow control, electronic expansion valve, conventional rss contain four main components. It takes the place of the condenser in conventional refrigeration systems. A phase change material pcm is a substance that can store or release significant amounts of heat energy by changing its phase from liquid to vapor or vice versa. Also covered in this chapter are the methods used for installing, maintaining, and repairing refrigeration equipment, including domestic refrigerators and freezers. Smith, extension food processing specialist jayne e. Consequently pressure and temperature are no longer interdependent during the heat rejection process. Defrosting methods adapted from material originally provided by kenneth s. Improve the cop of vapor compression cycle with change in ev aporator and condenser pressure by shoyab hussan. The non conventional refrigeration system works on the principle same as vapor compression refrigeration system. The nonconventional refrigeration system works on the principle same as vapor compression refrigeration system.
1552 664 630 117 1082 1 424 165 604 158 1000 569 995 1617 685 1079 251 171 886 415 1566 1176 1187 257 252 1105 717 1047 695 746 387 1503 202 1318 435 526 633 707 699 1436 486 381 921 43