Rankine cycle apparatus, combined heat and power system, and rankine cycle apparatus operation method

Abstract

A Rankine cycle apparatus includes a pump, an evaporator, an expander, a condenser, and an internal heat exchanger. The internal heat exchanger allows heat exchange to take place between a working fluid discharged from the expander and a working fluid discharged from the pump. A temperature of the working fluid at an inlet of the expander is set so that a temperature of the working fluid at an outlet of the expander be higher than a saturation temperature on a high-pressure side of the cycle.

1 - 11 . (canceled) 
     
     
         12 . A Rankine cycle apparatus comprising:
 a pump;   an evaporator;   an expander;   a condenser; and   an internal heat exchanger that allows heat exchange to take place between a working fluid, being a single organic fluid, discharged from the expander and the working fluid discharged from the pump, wherein   the Rankine cycle apparatus is configured such that:   a temperature of the working fluid at an inlet of the expander is set so that a temperature of the working fluid at an outlet of the expander is higher than the saturation temperature on a high-pressure side of the cycle; and   the working fluid at an inlet of the evaporator is in a liquid phase.   
     
     
         13 . The Rankine cycle apparatus according to  claim 12 , wherein the expander is a positive-displacement expander. 
     
     
         14 . A combined heat and power system comprising:
 the Rankine cycle apparatus according to  claim 12 ; and   a heat medium circuit in which a heat medium as a low-temperature heat source for cooling the working fluid in the condenser of the Rankine cycle apparatus flows.   
     
     
         15 . The combined heat and power system according to  claim 14 , wherein
 the heat medium is water, and   hot water produced in the condenser is used for at least one selected from hot water supply and space heating.   
     
     
         16 . The combined heat and power system according to  claim 14 , wherein
 the heat medium is air, and   hot air produced in the condenser is used for indoor heating.   
     
     
         17 . A method for operating a Rankine cycle apparatus, the Rankine cycle apparatus comprising: a pump; an evaporator; an expander; a condenser; and an internal heat exchanger that allows heat exchange to take place between a working fluid, being a single organic fluid, discharged from the expander and the working fluid discharged from the pump,
 the method comprising setting a temperature of the working fluid at an inlet of the expander so that a temperature of the working fluid at the outlet of the expander be higher than a saturation temperature on the high-pressure side of the cycle and the working fluid at an inlet of the evaporator is in a liquid phase.