Question

A 5 MW gas turbine power plant is reported to have a thermodynamic efficiency of 35%. Assume products of the combustion reaction exit at 750K with water in the gaseous phase. a. What is the corresponding heat rate of the power cycle

Answer 1

Answer:

The corresponding heat rate of the power cycle is  9749 BTU/kWh

Explanation:

Heat rate is the common measure of system efficiency in a steam power plant. It is defined as "the energy input to a system, typically in Btu/kWh, divided by the electricity generated, in kW."

Heat rate (BTU/kWh) = (Input Energy. Btu/hr)/(output power. kW)

Given;

Electrical energy output of gas turbine power plant = 5 MW = 5000 KW

Chemical energy input of the turbine = ?

Also, Efficiency = output power/input power

Given, efficiency = 35% = 0.35

0.35 = 5000 kW/input power

Input Power (kW) = 5000/0.35

Input Power (kW) = 14,285.7 KW

1 KW = 3412.142 BTU/hr

14,285.7 KW =   48,744,836.97 BTU/hr

Heat rate (BTU/kWh) = (Input Energy. Btu/hr)/(output power. kW)

Heat rate (BTU/kWh) = (48,744,836.97 BTU/hr)/(5000 KW)

Heat rate (BTU/kWh) = 9748.97 BTU/kWh = 9749 BTU/kWh

Therefore, the corresponding heat rate of the power cycle is  9749 BTU/kWh