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The heat of rejection, also known as just heat rejection, is when heat leaves a system. How much heat is lost depends on the system and its functionality.
Wiki User
∙ 9y ago
Wiki User
∙ 11y agoHeat rejection is the heat leaving a system.
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Why is there heat rejection in a thermodynamic process?
In a practical heat engine, heat is generated by burning a fuel, work is extracted from this heat resulting in the working fluid cooling, and heat is then rejected at the lower temperature. As you must know, in an internal combustion engine heat is rejected both in the engine cooling system and the exhaust. In a power plant, using water/steam as the working fluid in a closed cycle, there are four phases in the cycle: 1. Water is pumped at high pressure into a steam raising unit (boiler) 2. Heat from the fuel, be it coal, oil, gas, or nuclear, is added to the water causing it to become steam 3. the steam is expanded through a turbine doing work, that is driving the generator 4. the steam is condensed back to water using external cooling water. This is called the Rankine cycle. At stage 4 heat is being rejected into the external cooling water, and this heat is lost. It is minimised by running the condenser under vacuum so that steam at less than 100 celsius can still do work, and the final turbine discharge temperature is as low as 30C. Theoretically the efficiency of such a cycle is maximised by making the steam to the turbine as hot as material constraints allows, and the condenser vacuum as low as the local cooling water temperature will allow. The maximum practical efficiency of such a plant is about 42 percent, meaning that 58 percent of the heat from the fuel is rejected. For a PWR nuclear plant the steam temperature is much lower and the cycle efficiency is less, more like 30 percent. I hope this enables you to see why in a practical heat engine there must be heat rejection. There are several entries in Wikipedia for further reading, see 'Heat Engines' first.
Can a given amount of mechanical energy be converted into heat energy?
In any heat engine there is always some rejection of heat to the environment. Thus an internal combustion engine, as in a car, rejects heat in its exhaust gases, and also loses heat into its radiator. An aircraft jet engine rejects heat at its exhaust, it is impractical to extract more energy from this. In a power plant the steam turbine rejects heat to its condenser in order to condense the exhaust steam to water for feeding back to the boilers.
Why are the heat called the heat?
beacause its heat =P
How can you tell that you are absorbing radiant energy from the sun?
It will heat you up.It will heat you up.It will heat you up.It will heat you up.
How does a conductor absorb heat?
A conductor does not absorb heat, it conducts heat so that the heat is evenly dispersed. It seems like it absorbs heat but it transfers heat to somewhere else.
What is the formula for heat rejection rate?
Heat Rejection = mass x specific weight x specific density x difference in temp
Difference between heat rejection and heat absoarb in refrigerator?
Heat is absorbed by the refrigerant liquid inside the fridge, and rejected by the heat exchanger on the back of it.
What is main the function of condenser?
heat rejection through converctional or static means.(fan or air cooled condenser)
What has the author Mark League written?
Mark League has written: 'Solar dynamic heat rejection technology, Task 2'
What is one main function of the condenser?
heat rejection through converctional or static means.(fan or air cooled condenser)
What is a sentence with the word rejection?
an agent's job is full with Rejection. The rejection was inevitable.
What has the author Frederic Cook Scofield written?
Frederic Cook Scofield has written: 'Power plant heat rejection in an arid climate'
The rejection and non rejection regions are divided by the?
The rejection and non rejection regions are divided dividing point. critical value. point of no return. rejection value
Compare Brayton and Otto cycle?
The heat addition and rejection processes in otto cycle are of constant volume, whereas in brayton cycle, they are of constant pressure.
What is rejection of organ transplant called?
organ rejection
What is a total rejection of God's love?
there is no rejection from GODs love
What is total rejection of gods love?
there is no rejection from GODs love
