4. At steady state, a new power cycle is claimed by its inventor to develop power at a rate of (a) 90 hp, (b) 100 hp, (c) 110 hp for a heat rejection rate of 5.1 x 105 BTU/hr while operating between hot and cold reservoirs at 1000K and 500 K. Evaluate each claim. Is it impossible, reversible or irreversible

a) Possible

b) Possible

c) Possible

Explanation:

Given:

temperature of hot reservoir,

temperature of the cold reservoir,

heat rejected to the colder reservoir,

We know that:

so,

a)

power rate developed by the power,

Now the Carnot efficiency of the cycle:

.........................(1)

Now the actual efficiency of the cycle:

Since therefore the cycle is possible

b)

power rate developed by the power,

Now the actual efficiency of the cycle:

Since therefore the cycle is possible

c)

power rate developed by the power,

Now the actual efficiency of the cycle:

Since therefore the cycle is possible