I'm trying to get started on this problem but it looks like I don't have enough information to start it. I'll rewrite it:High pressure 20 degree Celsius water (no boiling) flows at 2 kg/s in a smooth 12 mm diameter pipe with pressurized super heated steam condensing on the outside in a heat exchanger. The steam maintains the pipe wall temperature at 140 degrees Celsius and the water flow is fully developed before entering the heat exchanger section that is 10 meters long. Determine Nu, h, exit temperature and total heat rate q in the heat exchanger. Assume water properties to be k = .613 W/m*K, cp = 4.179 kj/kg*K, u = 855x10^-6 kg/m*s, and Pr = 5.83.The water properties don't lead to any one temperature, and obviously determining T exit is essential in getting the rest of the information. I'm just unsure where exactly to start. I don't even have a value for density so I can't get velocity. Any hints would be appreciated.
If you prefer the hard way, look up heat exchanger in your text. This is a simple case, since the temp outside is fixed. You can set up the integral and integrate to get the temp. Or, should be able to use same inlet and outlet temp to use standard heat exchanger calcs derived in your text. It all gets back to the log mean temperature difference. Good luck!
