Hi,
I try to use Numerical method to simulate very short time temperature response of single U-tube, step by step. my time step is 0.0208333 [d],reference temperature and initial temperature is 11?,Qh is 4.32e8[J/d], refrigerant is water,other reference is fault value. figure 1 is the simulation result of the first step from 0[d] to 0.020833[d], I do not know why the temperature increase so rapidly in such a short time.
figure 2 shows the simulation start from 0.020833[day] to 0.041666[d], this result made me more confused, one is why the response temperature decrease first and then increase, and why it still increase very quickly? the other one is why the simulation temperature start from around 12.56?, why not start from the value gained from the first step ? what does the reference temperature mean?
Thanks in advance.
