Inlet controlled water heater regulating method

摘要

The hot-water heater concerned is divided into n compartments with n heating elements to be controlled, and the heat exchange between heating element and water and between water and wall. The energy balance of the compartments i, considering the water as thoroughly mixed as it flows through, is given by the following equations: x1 = q(t)/Vi x0 - x1+ a1(x2 - x1)+ a2(x3-x1); x2 = -a3(x2 - x1)+ b.u; x3 = -a4(x3 - x1), where (x1 is the water temp. of outflow from compartment), x3 is the wall temp. In matrix form, xi = Ai (t)+biu(t)+Bi(t)xi-1, where A and B are matrices and temperatures can be measured directly.