Question

A heat pump is used to heat a building. The external temperature is lower than the internal temperature. The pump's coefficient of performance is 3.52, and the heat pump delivers 4.09 MJ as heat to the building each hour. If the heat pump is a Carnot engine working in reverse, at what rate must work be done to run it?

Answer 1

ANS> The coefficient of heat pump is given by,

   . . . .(1)

where , W= the work done

,Q_L= the rejected heat

From the carnot cycle , we know that

where Q_H is the heat to be delivered

Hence we can modify equation (1), as below

=>

Now we will substitute the numerical values in the above equation and we get,

Now we will find the rate of work done by heat pump per second ,