Steam flow is typically measured in pounds per hour (lb/hr). Steam has a measure of heat that is given in British Thermal Units (Btu) per pound of steam. The heat in steam is also a function of the temperature and pressure of the steam. If the steam flow is known and the duration of flow is also known, then the steam flow can be converted into a measure of power in megawatts. Power plants use steam flow to turn steam turbines, which create electricity. Electricity generation is measured in megawatts.
Determine the heat of steam flow using the resource listed below. Assume there is 2,500 lb/hr of steam flow that has a pressure of 300 pounds per square inch (psi). This provides a heat input (enthalpy of saturated vapor) of 1,203.3 btu/lb.
Determine the heat input per unit of time by multiplying the steam flow by the heat input (25,000 lb/hr x 1,203.3 btu/lb), which is 30,083,500 btu/hr.
Convert the heat input from the steam flow into a unit of power in megawatts. This is done by using the conversion 1 btu/hr is equal to 2.93e-7 megawatts. Multiple the total heat input of 30,083,500 x 2.93e-7 for a result of 8.82 megawatts.