A) A gas-fired heat exchanger uses gas with energy value of 40MJ / m^3 at a rate of 0.4 m^3/h and produces 50kg/h of water at a temperature of 70^oC from feed water at 20^oC. The rest of the question is in the picture attached.PLZ help?
I got this
Let us calculate amount of heat required to raise the temperature of feed water at
Mass of water used in one hour
Rise in temperature
Heat produced by the gas in the heat exchanger in one hour
Thermal efficiency of the heat exchanger
#eta=10475000/16000000=0.65#, rounded to two decimal places.
Start by working out how much energy is required to heat 50 kg of water from
Specific heat capacity of water =
so 50 kg raised 50 degrees will need
Energy/hr in from gas
so thermal efficiency is