| 摘要 |
<p>In a method and a system for controlling the discharge temperature (Ta) of liquid from a valve, a mixing control valve (12; 110) is used for adjusting the mixing of at least two liquids supplied in variable proportions and having two substantially different temperatures (Th, Tc). The discharge temperature is calculated utilising data representing the inlet temperatures (Th, Tc) of the incoming liquids and the valve position ( theta ) employing the following equation: Ta = Tc + (Th - Tc)f( theta ) where Ta = discharge temperature Tc = cold liquid supply temperature Th = hot liquid supply temperature theta = angular position of the mixing valve f( theta ) = function of the valve angular position. The calculated discharge temperature (Ta) is compared with a required discharge temperature (TR). If the product of said comparison differs from zero, the relative proportions of the two incoming liquids are changed. Preferably the actual discharge temperature (Ta) of the liquid is sensed and also compared with the calculated discharge temperature (Ta). Again, if the product of this comparison differs from zero, the relative proportions of the incoming liquids are changed.</p> |
