If ten pounds of refrigerant gives up 20 BTUs of heat per pound in a water-cooled condenser, what is the leaving water temperature if the incoming water is at 80 degrees F?

To determine the leaving water temperature in a water-cooled condenser, we start by calculating the total heat transfer occurring with the refrigerant. In this scenario, ten pounds of refrigerant is releasing 20 BTUs of heat per pound. Therefore, the total heat rejected by the refrigerant can be calculated as follows:

Total heat released = Weight of refrigerant (pounds) × Heat rejection per pound (BTUs) Total heat released = 10 pounds × 20 BTUs/pound = 200 BTUs

Next, we need to establish how much the water temperature increases as it absorbs this amount of heat. The formula to find the temperature rise of the water is based on the specific heat capacity of water, which is approximately 1 BTU/(lb·°F). In this case, we are assuming that the flow rate of the water passing through the condenser is sufficient enough to allow for this heat absorption without any additional variables affecting the outcome.

Since we know the incoming water temperature is 80 degrees F, we can calculate the leaving water temperature by adding the temperature rise to the incoming water temperature:

Temp rise = Total heat absorbed by the water / Weight of water In this calculation, we are considering a flow rate of 1