Question

A power company desires to use groundwater from a hot spring to power a heat engine. If the groundwater is at 95 deg C and the atmosphere is at 20 deg C, what is the maximum power output for a mass flow of 0.2 kg/s? Assume the water is cooled to atmospheric temperature.

Answer 1

W = 12.8 KW

Step-by-step explanation:

given data:

mass flow rate = 0.2 kg/s

Engine recieve heat from ground water at 95 degree ( 368 K) and reject that heat to atmosphere at 20 degree (293K)

we know that maximum possible efficiency is given as

`\eta = 1- (T_L)/(T_H)`

`\eta = 1 - ( 293)/(368)`

`\eta = 0.2038`

rate of heat transfer is given as

`Q_H = \dot m C_p \Delta T`

`Q_H = 0.2 * 4.18 8(95 - 20)`

`Q_H = 62.7 kW`

Maximuim power is given as

`W = \eta Q_H`

W = 0.2038 * 62.7

W = 12.8 KW