A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the niche application Stirling engine. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.
A Stirling engine is a heat engine that is operated by a cyclic compression and expansion of air or other gas at different temperatures, such that there is a net conversion of heat energy to mechanical work. More specifically, the Stirling engine is a closed-cycle regenerative heat engine with a permanently gaseous working fluid. Closed-cycle, in this context, means a thermodynamic system in which the working fluid is permanently contained within the system, and regenerative describes the use of a specific type of internal heat exchanger and thermal store, known as the regenerator. Strictly speaking, the inclusion of the regenerator is what differentiates a Stirling engine from other closed cycle hot air engines.
An intercooler is a mechanical device used to cool a gas after compression. Compressing a gas increases its internal energy which in turn raises its temperature and reduces its density. An intercooler typically takes the form of a heat exchanger that removes waste heat in a gas compressor. Intercoolers have a variety of applications, and can be found in air compressors, air conditioners, refrigeration, and gas turbines, and automotive engines, for example. They are widely known as an air-to-air or air-to-liquid cooler for forced induction internal combustion engines, used to improve volumetric efficiency. This is accomplished by increasing intake air density through nearly constant pressure cooling.
The Stirling cycle is a thermodynamic cycle that describes the general class of Stirling devices. This includes the original Stirling engine that was invented, developed and patented in 1816 by Robert Stirling with help from his brother, an engineer.
An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling differs from typical air conditioning systems, which use vapor-compression or absorption refrigeration cycles. Evaporative cooling uses the fact that water will absorb a relatively large amount of heat in order to evaporate. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation). This can cool air using much less energy than refrigeration. In extremely dry climates, evaporative cooling of air has the added benefit of conditioning the air with more moisture for the comfort of building occupants.
A refrigerator designed to reach cryogenic temperatures is often called a cryocooler. The term is most often used for smaller systems, typically table-top size, with input powers less than about 20 kW. Some can have input powers as low as 2-3 W. Large systems, such as those used for cooling the superconducting magnets in particle accelerators are more often called cryogenic refrigerators. Their input powers can be as high as 1 MW. In most cases cryocoolers use a cryogenic fluid as the working substance and employ moving parts to cycle the fluid around a thermodynamic cycle. The fluid is typically compressed at room temperature, precooled in a heat exchanger, then expanded at some low temperature. The returning low-pressure fluid passes through the heat exchanger to precool the high-pressure fluid before entering the compressor intake. The cycle is then repeated.
The Ericsson cycle is named after inventor John Ericsson who designed and built many unique heat engines based on various thermodynamic cycles. He is credited with inventing two unique heat engine cycles and developing practical engines based on these cycles. His first cycle is now known as the closed Brayton cycle, while his second cycle is what is now called the Ericsson cycle. Ericsson is one of the few who built open-cycle engines, but he also built closed-cycle ones.
A refrigerator consists of a thermally insulated compartment and a heat pump that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the room temperature. Refrigeration is an essential food storage technique in developed countries. The lower temperature lowers the reproduction rate of bacteria, so the refrigerator reduces the rate of spoilage. A refrigerator maintains a temperature a few degrees above the freezing point of water. Optimum temperature range for perishable food storage is 3 to 5 °C. A similar device that maintains a temperature below the freezing point of water is called a freezer. The refrigerator replaced the icebox, which had been a common household appliance for almost a century and a half.
The Amana Corporation is an American brand of household appliances. It was founded in 1934 by George Foerstner as The Electrical Equipment Co. in Middle Amana, Iowa, to manufacture commercial walk-in coolers. The business was later owned by the Amana Society and became known as Amana Refrigeration, Inc. It is now owned by the Whirlpool Corporation.
Smeg S.p.A. is an Italian manufacturer of domestic appliances. Vittorio Bertazzoni founded the company in 1948 in the town of Guastalla, Reggio Emilia, Italy. The name is an acronym for Smalterie Metallurgiche Emiliane Guastalla.
Economizers, or economisers (UK), are mechanical devices intended to reduce energy consumption, or to perform useful function such as preheating a fluid. The term economizer is used for other purposes as well. Boiler, power plant, heating, refrigeration, ventilating, and air conditioning (HVAC) uses are discussed in this article. In simple terms, an economizer is a heat exchanger.
Voltas Limited, is an Indian Home appliances company specialising in air conditioning and cooling technology. The company is broadly structured into projects and products business. The projects business is divided into Domestic Projects Group (DPG) and International Operations Business Group (IOBG). Meanwhile, the products business is classified into Unitary Products Business Group (UPBG), Mining & Construction Equipment Division (MCED), and Textile Machinery Division. (TMD).
Engine efficiency of thermal engines is the relationship between the total energy contained in the fuel, and the amount of energy used to perform useful work. There are two classifications of thermal engines-
- Internal combustion and
- External combustion engines.
The Harwell TMG Stirling engine, an abbreviation for "Thermo-Mechanical Generator", was invented in 1967 by E. H. Cooke-Yarborough at the Harwell Labs of the United Kingdom Atomic Energy Authority. It was intended to be a remote electrical power source with low cost and very long life, albeit by sacrificing some efficiency. The TMG was at one time the only Stirling engine sold by a manufacturer, namely HoMach Systems Ltd., England.
The pulse tube refrigerator (PTR) or pulse tube cryocooler is a developing technology that emerged largely in the early 1980s with a series of other innovations in the broader field of thermoacoustics. In contrast with other cryocoolers, this cryocooler can be made without moving parts in the low temperature part of the device, making the cooler suitable for a wide variety of applications.
A liquid nitrogen vehicle is powered by liquid nitrogen, which is stored in a tank. Traditional nitrogen engine designs work by heating the liquid nitrogen in a heat exchanger, extracting heat from the ambient air and using the resulting pressurized gas to operate a piston or rotary motor. Vehicles propelled by liquid nitrogen have been demonstrated, but are not used commercially. One such vehicle, Liquid Air was demonstrated in 1902.
Applications of the Stirling engine range from mechanical propulsion to heating and cooling to electrical generation systems. A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the "working fluid", at different temperature levels such that there is a net conversion of heat to mechanical work. The Stirling cycle heat engine can also be driven in reverse, using a mechanical energy input to drive heat transfer in a reversed direction.
Symphony Limited is Indian Manufacturer company of durables products located in Ahmedabad, Gujarat, India was established in the year 1988. It is a public limited, listed company. It manufactures products like domestic air coolers, industrial air coolers. Symphony has its operations in about 60 countries.. It is also certified by the Guinness World Record Ltd. for manufacturing the world's largest functioning air cooler.
An internal combustion engine (ICE) is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is applied typically to pistons, turbine blades, rotor or a nozzle. This force moves the component over a distance, transforming chemical energy into useful work.
Many vaccines require refrigeration to remain active, and the lack of infrastructure to maintain the cool chain to reliably bring vaccines into more remote areas of developing countries poses a serious challenge to national immunization programs. Post millennium, a portable vaccine cooler unit has been proposed by several technologists. The WHO Performance, Quality and Safety (PQS) programme is a driver of the technology.
