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Thermodynamic heat pump cycles or refrigeration cycles are the conceptual and mathematical models for heat pump, air conditioning and refrigeration systems. [1] A heat pump is a mechanical system that transmits heat from one location (the "source") at a certain temperature to another location (the "sink" or "heat sink") at a higher temperature ...
In the United States, in everyday usage the SEER is the more common measure of energy efficiency for cooling devices, as well as for heat pumps when in their heating mode. For energy-conversion heating devices their peak steady-state thermal efficiency is often stated, e.g., 'this furnace is 90% efficient', but a more detailed measure of ...
cycle per second: cps ≡ 1 Hz = 1 cps = 1 Hz degree per second: deg/s ≡ 1 °/s ≡ 1/360 Hz = 0.002 7 Hz hertz (SI unit) Hz ≡ One cycle per second = 1 Hz = 1/s radian per second: rad/s ≡ 1/(2π) Hz ≈ 0.159 155 Hz: revolution per minute: rpm ≡ One rpm equals one rotation completed around a fixed axis in one minute of time. ≈ 0.104 ...
TSFC or SFC for thrust engines (e.g. turbojets, turbofans, ramjets, rockets, etc.) is the mass of fuel needed to provide the net thrust for a given period e.g. lb/(h·lbf) (pounds of fuel per hour-pound of thrust) or g/(s·kN) (grams of fuel per second-kilonewton). Mass of fuel is used, rather than volume (gallons or litres) for the fuel ...
A Carnot cycle is an ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. By Carnot's theorem, it provides an upper limit on the efficiency of any classical thermodynamic engine during the conversion of heat into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference through ...
The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required. [ 1 ] [ 2 ] Higher COPs equate to higher efficiency, lower energy (power) consumption and thus lower operating costs.
In most countries, using the metric system, fuel economy is stated as "fuel consumption" in liters per 100 kilometers (L/100 km) or kilometers per liter (km/L or kmpl).
Two primary classes of thermodynamic cycles are power cycles and heat pump cycles. Power cycles are cycles which convert some heat input into a mechanical work output, while heat pump cycles transfer heat from low to high temperatures by using mechanical work as the input. Cycles composed entirely of quasistatic processes can operate as power ...