No action will be held without loss - it is always there.The result is always less than the efforts that have to spend to achieve it.About how large losses in performing the work, and indicates the efficiency (COP).
What lies behind this abbreviation?In fact, it is the coefficient of efficiency of the mechanism and rate of rational use of energy.The value has no efficiency some units, it is expressed as a percentage.This factor is determined as the ratio of useful work to the device spent on its functioning.To calculate the efficiency of the calculation formula would look like this:
efficiency = 100 * (made useful work / work expended)
in various devices for the calculation of this ratio using different values.For the efficiency of electric motors will appear as the ratio of useful work done by the to the electrical energy received from the network.For the thermal efficiency of the machines will be determined as the ratio of useful work done by the number of expended to heat.
To determine the efficiency necessary for all the different types of energy and work are expressed in the same units.Then it will be possible to compare any objects such as nuclear power plants, power generators, and biological objects, in terms of efficiency.
As already noted, due to unavoidable losses in the efficiency of the mechanisms is always less than 1. Thus, the efficiency of thermal power plants to reach 90% in the efficiency of internal combustion engines is less than 30%, the efficiency of the electrical transformer is 98%.The concept of efficiency can be used as a mechanism in general, and to its individual nodes.With an overall evaluation of the effectiveness of the mechanism as a whole (its efficiency) is taken work efficiency of individual components of the device.
problem of fuel efficiency did not appear today.With the continuous increase in the cost of energy efficiency improvement mechanisms question is transformed from a purely theoretical into a practical question.If the efficiency of a conventional vehicle does not exceed 30%, then 70% of the money spent on fuel for the car, we just throw away.
Consideration of the efficiency of the internal combustion engine (internal combustion engine) shows that losses occur at all stages of its work.Thus, only 75% of the incoming fuel is combusted in cylinders of the engine, and 25% is emitted.Of all the burnt fuel is only 30-35% of the released heat is used to perform useful work, or else the heat is lost with the exhaust gases, or remains in the cooling system of the car.From the resulting power to useful work used about 80%, the rest of the power is spent on overcoming the forces of friction and auxiliary machinery used car.
Even this simple example, the analysis of the effectiveness of the mechanism to determine the direction in which the work must be carried out in order to reduce losses.So, one of the priorities - ensuring complete combustion.This is achieved by additional spray of fuel and the pressure increases, so it is becoming popular engines with direct injection and turbocharging.The heat carrier from the engine is used to heat the fuel to its better evaporation and mechanical losses are reduced by using modern synthetic oil grades.
Here we considered such a thing as efficiency, explains what it is and what does.Consider the example of the engine's efficiency and identify areas and ways to improve the capabilities of the device, and consequently the efficiency.
