A new signal for the thermostatic valve.

Some experiments about the stability of the refrigerating circuit fed by a thermostatic valve show a peculiar behaviour of the temperatures of the evaporating fluids at the outlet of the evaporator. When the flow rate increases, the temperature in the upper and lower sides of the tube becomes more and more different; this behaviour is correlated with the superheat of the vapour. The authors propose to replace the superheat signal by this difference. The advantages of this choice are discussed.