1 Expert Answer. Assuming very large heat & cold sinks, you can increase the Carnot efficiency by increasing the hot temperature or by decreasing the cold temperature!
How can you increase the efficiency of a heat engine?
Therefore, the efficiency of the heat engine can be increased by decreasing the temperature of the cold sink or increasing the temperature of the hot source.
What is the efficiency of heat engine?
Heat engines often operate at around 30% to 50% efficiency, due to practical limitations. It is impossible for heat engines to achieve 100% thermal efficiency () according to the Second law of thermodynamics.
Can we increase the efficiency of a heat engine by increasing the amount of working substance Why?
More work is done by the system in the first half of the cycle if you raise the temperature of the the hot reservoir, and less heat is “wasted” if you lower the temperature of the cold reservoir for the recovery steps. Hence the efficiency is increased by increasing the difference in temperature between the reservoirs.
Which is the more effective way to increase the efficiency of a Carnot engine to increase t1 keeping t2 constant or to decrease t2 keeping t1 constant?
Hence efficiency of carnot engine can be increased by a greater amount by increasing the temp. of source by 10K.
Is Carnot engine 100 efficient?
In order to achieve 100% efficiency (η=1), Q2 must be equal to 0 which means that all the heat form the source is converted to work. The temperature of sink means a negative temperature on the absolute scale at which the temperature is greater than unity.
Why is a heat engine not 100% efficient?
A heat engine is considered to be 100% efficient if only all the heat is converted into useful work or mechanical energy. Since heat engines cannot convert all the heat energy into mechanical energy, their efficiency can never be 100%.
What is the formula of thermal efficiency?
The thermal efficiency, ηth, represents the fraction of heat, QH, that is converted to work. The air-standard Otto cycle thermal efficiency is a function of compression ratio and κ = cp/cv. Note that, ηth could be 100% only if the waste heat QC will be zero. …
What is the formula of efficiency?
Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula r=P/C, where P is the amount of useful output (“product”) produced per the amount C (“cost”) of resources consumed.
What is the most efficient heat engine?
The most efficient heat engine cycle is the Carnot cycle, consisting of two isothermal processes and two adiabatic processes. The Carnot cycle can be thought of as the most efficient heat engine cycle allowed by physical laws.
What are the factors to thermal efficiency?
In theory, the factors that affect thermal efficiency (the performance of an engine or the work it has done in relation to the value of heat supplied to it) are the heat input and the heat output. Additionally, temperature variations also come in play, the amount and the rate of losing or gaining heat.
What is the basic principle of heat engine?
In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature.
How can I improve the thermal efficiency of my house?
Ways to improve your home to make it energy efficient
- Reduce your heating or use a secondary heating source.
- Use a new, energy efficient boiler.
- Fit insulation.
- Double or triple glazing.
- Draught proofing.
- Generate your own energy from renewable sources.
- Energy efficient fittings.
How do you increase Carnot efficiency?
The efficiency of the carnot engine can be increased by either increasing the sink temperature or by decreasing the reservoir temperature.
What is Carnot cycle efficiency?
The ideal Rankine cycle efficiency (or Carnot cycle efficiency) can be defined as (T2-T1)/T2. T2 is defined as the absolute temperature of the heat source and T1 is the absolute temperature of the heat sink.
What is T1 and T2 in Carnot cycle?
Carnot efficiency is independent of working substance. Heat flows (Q1 and Q2) are determined solely by the reservoir temperatures (T1 and T2). Can define a temperature scale based on thermodynamic principles. … consider ideal gas as a working substance.