Find mass flow rate using heat differential

AI Thread Summary
The discussion centers on calculating the mass flow rate of cold water in an experimental power plant utilizing ocean temperature gradients. Given the surface temperature of 25°C, deep-water temperature of 7°C, and the exit temperature of 12°C, the challenge is to determine the flow rate in kg/s and L/s. Key equations include the work-energy relationship and the specific heat capacity of water. Participants emphasize the need for additional information, such as the electrical power output of the plant, to accurately determine the required flow rate. Understanding the relationship between temperature change, specific heat, and flow rate is crucial for solving the problem.
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Homework Statement



An experimental power plant at the Natural Energy Laboratory of Hawaii generates electricity from the temperature gradient of the ocean. The surface and deep-water temperatures are 25°C and 7°C respectively.

The cold water that enters the plant leaves it at a temperature of 12°C What must be the flow rate of cold water through the system? Give your answer in kg/s & L/s.

dm/dt = ?

Homework Equations



W = QH - QC
e = 1 - TC / TH
cwater = 4190 J/kg*K

The Attempt at a Solution



I understand that it takes a certain amount of time to raise the water from 7°C to 12°C, but I don't know how to find that or how to relate it to a flow rate.
 
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remember what you have and what you want to know. you have ΔT, c, and P (which is Q/t) and you want kg/s (which is mass/time)...i think there is an equation for that, do you remember it? remember, your answer is going to be in kg/s.
 
How much electrical power is the plant supposed to generate? That would seem to be a critical bit of information in determining how much flow is required.
 

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