A heat energy recovery system includes an evaporator, a superheater, an expander, a power recovery device, a condenser, a pump, and a controller. The controller includes: an engine load calculation section; a maximum rotation speed determination section for determining a maximum rotation speed of the pump which is obtained when a pinch temperature reaches a target pinch temperature, based on a relational expression representing a relationship between the engine load and the maximum rotation speed, and an engine load; and a rotation speed regulation section for regulating the rotation speed of the pump in such a way as to allow the degree of superheat of the working medium flowing into the expander to be equal to or greater than a reference value, and to allow the rotation speed to be equal to or less than a maximum rotation speed determined by the maximum rotation speed determination section.

A pressure regulator assembly including a regulator valve, a spring guide, a spring extending between the spring guide and regulator valve for setting operation of the regulator valve, a sleeve coupled to the spring guide, a spring cage coupled to the sleeve, an adjustment stem coupled to the sleeve, a dial assembly coupled to the spring cage, and an adjustment cap coupled to the adjustment stem, wherein when the cap is depressed, interaction between the spring cage, spring guide and sleeve causes the spring guide to selectively rotate between a normal mode and a fast-fill mode. In the normal mode, adjustment of the cap determines an output pressure. In the fast-fill mode, the spring is further compressed by movement of the spring guide to a predetermined setting to provide a predetermined output pressure.

A heat energy recovery system includes an evaporator, a superheater, an expander, a power recovery device, a condenser, a pump, and a controller. The controller includes: an engine load calculation section; a maximum rotation speed determination section for determining a maximum rotation speed of the pump which is obtained when a pinch temperature reaches a target pinch temperature, based on a relational expression representing a relationship between the engine load and the maximum rotation speed, and an engine load; and a rotation speed regulation section for regulating the rotation speed of the pump in such a way as to allow the degree of superheat of the working medium flowing into the expander to be equal to or greater than a reference value, and to allow the rotation speed to be equal to or less than a maximum rotation speed determined by the maximum rotation speed determination section.