efficiency coefficient
COP- describes the heating and cooling efficiency of air conditioning units. It indicates the ratio of heating or cooling provided by the unit with respect to the consumption of electrical energy required to generate it. In principle, the higher the COP values, the more energy efficient the device is.
Efficiency is a dimensionless number that expresses how close to the ideal process the process is in the evaluated machine or equipment. The efficiency is calculated as the ratio of the monitored quantity at the output of the device to the monitored quantity at the input of the device in the same time period. An ideal process is 100% efficient. The up to 100% efficiency plugin evaluates the amount of process losses.
The Greek letter η (eta) is usually used to indicate efficiency. In general, we can write:
η = {\displaystyle {\frac {A_{o}}{A_{p}}}={\frac {A_{p}-As}{A_{p}}}=1-{\frac {A_{s) }}{A_{p}}}}
η - efficiency
Ao - monitored quantity at the outlet (deducted)
Ap - monitored quantity at the input (supplied)
As - unused part of the quantity (loss)
Efficiency is most often used to compare energies (e.g. mechanical work) or power, but for various technical applications other quantities (e.g. volume) may be monitored. It is important that the compared quantities are equivalent, i.e. j. they had the same physical units. By efficiency, we can evaluate the device as a whole, or we can evaluate only part of the process (function) of the device, or compare the real device with its theoretical or other model.
When comparing energy, we can evaluate:
energy transfer efficiency - for example, in a car transmission, there is mechanical work at both the input and the output
efficiency of energy conversion - for example, in an internal combustion engine, the input is chemical energy in the fuel and the output is mechanical work.
It follows from the above that we can define and use a large number of efficiencies within technical devices. In fact, this is what happens, the individual efficiencies have their own established names and designations with an index next to the symbol η.
For the energy evaluation of machines in general, the following main efficiencies are used:
Effective efficiency or overall energy efficiency - which evaluates the efficiency of the entire device. It is calculated from the ratio of the values of the energy supplied to the device and the energy removed from the device.
Mechanical efficiency - which evaluates the efficiency of the mechanical parts of the device. It is calculated from the ratio of the values of the mechanical work at the input of the device and the mechanical work removed from the device.
Exergetic efficiency - which evaluates the efficiency of the entire device taking into account only the available part of the energy in relation to the state of the environment (so-called exergy). It is calculated from the ratio of the values of exergy supplied to the device and energy removed from the device.