if main steam header pressure is 160psi.Will Pressure regulation at inlet of heat exchanger help to descipate more heat?
I will suppose that the design of the heat exchanger is adequate, that air has been removed from the steam condensing surfaces. Also that the medium being heated has a desired temperature somewhat below 370 F (for 175 psia) or 363F (for 160 psia) The driving force in heat exchange is temperature difference. If the rate of heat exchange is insufficient, the temperature difference needs to be raised by increasing the condensing pressure of the steam, not lowering it. The pressure regulator should be reset for a higher pressure. If the regulator is already wide open and the condensing pressure is already at 160 psi and insufficient, the initial pressure of the steam supply must be raised.
If your steam is 100% pure steam, I can't see how dropping the pressure would help, in fact you loose some energy due to entropy loss by going through the pressure regulator. However, if your main steam is less than 100% pure, a steam/water mix, it might help. If you drop the pressure, at least some of the water would flash to steam and condensing steam has a much higher heat transfer coefficient than flowing water. This may increase the amount of heat transfer in the exchanger.
