Need help regarding heat transfer questions

AI Thread Summary
The discussion revolves around three specific heat transfer questions requiring calculations. The first question involves determining the time needed to heat a 500-litre water cylinder from 12°C to 60°C using a 30kW heat source. The second question seeks to find the mass flow rate of a 400kW plate heat exchanger with specified inlet and outlet temperatures. The final question asks for the inlet temperature of water entering a heat exchanger to achieve a flow rate of 5kg/s from a 210kW source at 20°C. Participants are encouraged to share their attempts and challenges to receive targeted assistance.
wattsie10
Messages
1
Reaction score
0
Please can someone show me how to work out the following questions.

1) A hot water cylinder holds 500 litres. If the primary heat source is 30kW and the supply water inlet to the cylinder is 12°C, how long will it take to heat the whole tank to 60°C?

2) The primary side of a plate heat exchanger rated at 400kW has an inlet temperature of 85°C and the outlet temperature is 40°C. What is the mass flow rate?

3) To achieve a water flow rate of 5kg/s at 20°C from a 210kW source, what would be the temperature of the water as it enters the heat exchanger?

Many thanks
 
Physics news on Phys.org
Welcome to PF!

Hi wattsie10! Welcome to PF! :wink:

Show us what you've tried, and where you're stuck, and then we'll know how to help! :smile:
 
Back
Top