Is isothermal heat addition possible?
Table of Contents
- 1 Is isothermal heat addition possible?
- 2 Why Carnot cycle is not possible?
- 3 Can a Carnot heat engine attain 100\% efficiency justify your answer?
- 4 Which is the cycle with isothermal heat addition?
- 5 Why Carnot cycle efficiency is maximum?
- 6 Why is it impossible to have a 100\% efficient engine?
- 7 Why isothermal heat addition is reversible?
- 8 What is the energy added during the Carnot isothermal expansion?
- 9 What is the Carnot cycle?
- 10 How does entropy relate to the heat rejected by an engine?
Is isothermal heat addition possible?
Isothermal heat addition is only possible when the process is very slow and steadily(temperature not vary with time). Which actually means the whole heat supplied to the system completely used to increase the volume ( expansion of gas) without considering any losses.
Why Carnot cycle is not possible?
In real engines, the heat transfers at a sudden change in temperature whereas in a Carnot engine, the temperature remains constant. In our day to day lives, reversible processes can’t be carried out and there is no such engine with 100 \% efficiency. Thus, the Carnot cycle is practically not possible.
Is it possible to have a heat engine functioning with a Carnot cycle?
The Carnot cycle is a theoretical cycle that is the most efficient cyclical process possible. Any engine using the Carnot cycle, which uses only reversible processes (adiabatic and isothermal), is known as a Carnot engine. Any engine that uses the Carnot cycle enjoys the maximum theoretical efficiency.
Can a Carnot heat engine attain 100\% efficiency justify your answer?
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.
Which is the cycle with isothermal heat addition?
Well-known thermodynamic cycles
Cycle | Compression, 1→2 | Heat addition, 2→3 |
---|---|---|
Power cycles normally with external combustion – or heat pump cycles: | ||
Carnot | isentropic | isothermal |
Ericsson | isothermal | isobaric |
Rankine | adiabatic | isobaric |
What is isothermal heat rejection?
During the isothermal heat rejection process of a Carnot cycle, the working fluid experiences an entropy change of -0.7 Btu/R. If the temperature of the heat sink is 95°F, determine (a) the amount of heat transfer, (b) the entropy change of the sink, and (c) the total entropy change for this process.
Why Carnot cycle efficiency is maximum?
The Carnot cycle is reversible representing the upper limit on the efficiency of an engine cycle. The Carnot cycle achieves maximum efficiency because all the heat is added to the working fluid at the maximum temperature.
Why is it impossible to have a 100\% efficient engine?
It is impossible for heat engines to achieve 100\% thermal efficiency () according to the Second law of thermodynamics. This is impossible because some waste heat is always produced produced in a heat engine, shown in Figure 1 by the term.
Why is it impossible to have an efficiency of 100\% on engines?
The efficiency of a heat engine can be 100\% only if all the heat energy gets converted into work (or mechanical energy). Since heat energy can never be transformed completely into mechanical energy, so the efficiency of a heat engine can never be 100 per cent.
Why isothermal heat addition is reversible?
Reversible Isothermal Heat Addition In the first process, the cylinder head is brought into contact with a source at temperature . The gas inside the cylinder is also at temperature . The gas expands reversibly and isothermally . During this process, the system absorbs energy as heat from the source.
What is the energy added during the Carnot isothermal expansion?
The energy added to a working fluid during the Carnot isothermal expansion is given by qs. Not all of this energy is available for use by the heat engine since a portion of it (qr) must be rejected to the environment. and is equal to the area of the shaded region labeled available energy in Figure 28 between the emperatures 1962 and 520R.
What is meant by isothermal expansion?
Isothermal Expansion. Isothermal expansion is performed, absorbing heat from the low temperature heat source T1. From: Solar-Hydrogen Energy Systems, 1979. Related terms: Energy Engineering; Pistons; Thermodynamics; Carnot Cycle; Ideal Gas; Isothermal Compression; Temperature (T) Regenerator
What is the Carnot cycle?
The Carnot cycle is an imaginary energy conversion cycle (heat to mechanical energy) in which all four parts of the cycle are “reversible.” Two parts of the cycle transfer heat across differential (tiny) temperature differences and the other two parts have zero heat transfer (adiabatic). This is the most efficient imaginable heat engine.
How does entropy relate to the heat rejected by an engine?
If the temperature of the heat sink is known, then thec hange in entropy does correspond to a measure of the heat rejected by the engine Figure 29 is a typical power cycle employed by a fossil fuel plant. The working fluid is water, which places certain restrictions on the cycle.