Rhetorical Functions in Academic Writing: Describing processes Examples Here is a description of the process of sorting letters. First of all, letters and packets are collected in bags from pillar boxes, post offices and firms, in post office vans.
Similarly, a refrigerator moves heat from inside the cold icebox the heat source to the warmer room-temperature air of the kitchen the heat sink.
The operating principle of the refrigeration cycle was described mathematically by Sadi Carnot in as a heat engine. A heat pump can be thought of as a heat engine which is operating in reverse.
Refrigerator Definitions Of A Right And Left Hand Door Right Hand Refrigerator Door: As you face the front of the refrigerator the handle . · How to Write a Descriptive Paragraph. In this Article: Article Summary Sample Paragraphs Describing a Person Writing about an Object Writing a Descriptive Paragraph About a Place Community Q&A If you want to immerse a reader in an essay or story, there’s no better way to do it than with a crisp, vivid descriptive benjaminpohle.com://benjaminpohle.com · A refrigerator or heat pump that acts on the reversed Carnot cycle is called a Carnot refrigerator and Carnot heat pump respectively. In the first stage of this cycle (process ), the refrigerant absorbs heat isothermally from a low-temperature source, T L, in the amount Q benjaminpohle.comdynamic cycles · Coefficient of performance · References · External linksbenjaminpohle.com
Heat pump and refrigeration cycles can be classified as vapor compression, vapor absorption, gas cycle, or Stirling cycle types. Vapor-compression cycle Main article: Vapor-compression refrigeration The vapor-compression cycle is used in most household refrigerators as well as in many large commercial and industrial refrigeration systems.
Figure 1 provides a schematic diagram of the components of a typical vapor-compression refrigeration system. Vapor-compression refrigeration The thermodynamics of the cycle can be analysed on a diagram   as shown in Figure 2.
In this cycle, a circulating working fluid commonly called refrigerant such as Freon enters the compressor as a vapor. The vapor is compressed at constant entropy and exits the compressor superheated.
The superheated vapor travels through the condenser which first cools and removes the superheat and then condenses the vapor into a liquid by removing additional heat at constant pressure and temperature.
The liquid refrigerant goes through the expansion valve also called a throttle valve where its pressure abruptly decreases, causing flash evaporation and auto-refrigeration of, typically, less than half of the liquid.
Temperature—Entropy diagram of the vapor-compression cycle. That results in a mixture of liquid and vapor at a lower temperature and pressure. The cold liquid-vapor mixture then travels through the evaporator coil or tubes and is completely vaporized by cooling the warm air from the space being refrigerated being blown by a fan across the evaporator coil or tubes.
The resulting refrigerant vapor returns to the compressor inlet to complete the thermodynamic cycle. The above discussion is based on the ideal vapor-compression refrigeration cycle, and does not take into account real-world effects like frictional pressure drop in the system, slight thermodynamic irreversibility during the compression of the refrigerant vapor, or non-ideal gas behavior if any.
Vapor absorption cycle Main article: Absorption refrigerator In the early years of the twentieth century, the vapor absorption cycle using water-ammonia systems was popular and widely used but, after the development of the vapor compression cycle, it lost much of its importance because of its low coefficient of performance about one fifth of that of the vapor compression cycle.
Nowadays, the vapor absorption cycle is used only where heat is more readily available than electricity, such as waste heat provided by solar collectorsor off-the-grid refrigeration in recreational vehicles. The absorption cycle is similar to the compression cycle, except for the method of raising the pressure of the refrigerant vapor.
In the absorption system, the compressor is replaced by an absorber which dissolves the refrigerant in a suitable liquid, a liquid pump which raises the pressure and a generator which, on heat addition, drives off the refrigerant vapor from the high-pressure liquid.
Some work is required by the liquid pump but, for a given quantity of refrigerant, it is much smaller than needed by the compressor in the vapor compression cycle.
In an absorption refrigerator, a suitable combination of refrigerant and absorbent is used. The most common combinations are ammonia refrigerant and water absorbentand water refrigerant and lithium bromide absorbent. Gas cycle When the working fluid is a gas that is compressed and expanded but does not change phase, the refrigeration cycle is called a gas cycle.
Air is most often this working fluid. As there is no condensation and evaporation intended in a gas cycle, components corresponding to the condenser and evaporator in a vapor compression cycle are the hot and cold gas-to-gas heat exchangers. For given extreme temperatures, a gas cycle may be less efficient than a vapor compression cycle because the gas cycle works on the reverse Brayton cycle instead of the reverse Rankine cycle.
As such, the working fluid never receives or rejects heat at constant temperature. In the gas cycle, the refrigeration effect is equal to the product of the specific heat of the gas and the rise in temperature of the gas in the low temperature side. Therefore, for the same cooling load, gas refrigeration cycle machines require a larger mass flow rate, which in turn increases their size.
Because of their lower efficiency and larger bulk, air cycle coolers are not often applied in terrestrial refrigeration. The air cycle machine is very common, however, on gas turbine -powered jet airliners since compressed air is readily available from the engines' compressor sections.
These jet aircraft's cooling and ventilation units also serve the purpose of heating and pressurizing the aircraft cabin. Stirling engine Main article: Stirling engine The Stirling cycle heat engine can be driven in reverse, using a mechanical energy input to drive heat transfer in a reversed direction i.
There are several design configurations for such devices that can be built.
Several such setups require rotary or sliding seals, which can introduce difficult tradeoffs between frictional losses and refrigerant leakage. Reversed Carnot cycle Since the Carnot cycle is a reversible cycle, the four processes that comprise it, two isothermal and two isentropic, can all be reversed as well.a refrigerator, refrigerator compartment, cabinet, or room held at or below 32°F (0°C), used especially for preserving and storing food.
a machine containing cold brine, ice, etc., for making ice cream, sherbet, or the like. a person or thing that freezes or benjaminpohle.com://benjaminpohle.com Describing A Refrigerator Before refrigerators were produced, people were forced to cool their food with ice, snow, or nearby rivers and springs.
Most people also had to can, salt, and pickle their food to preserve their meals. During benjaminpohle.com · a refrigerator b. an electric fan c. a television d. an oven Activity I Instructions: Read the following information and answer the questions.
In the summertime, have you ever gotten out of a swimming pool and then felt very cold standing in the sun? Discuss and conclude the language for describing a work benjaminpohle.com · Rhetorical Functions in Academic Writing: Describing processes Examples. Here is a description of the process of sorting letters.
First of all, letters and packets are collected in bags from pillar boxes, post offices and firms, in post office vans. They are then taken to the sorting office, where the bags are emptied and the letters separated benjaminpohle.com Describing objects worksheets High Quality ESL Lesson Plans - Free Samples - $26 Membership Be a better teacher!
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Zero preparation time required. Listening lesson plans with mp3 files also benjaminpohle.com › Vocabulary worksheets › General vocabulary. · How to Write a Descriptive Paragraph. In this Article: Article Summary Sample Paragraphs Describing a Person Writing about an Object Writing a Descriptive Paragraph About a Place Community Q&A If you want to immerse a reader in an essay or story, there’s no better way to do it than with a crisp, vivid descriptive benjaminpohle.com://benjaminpohle.com