Waste heat recovery turbine system

Abstract

Provided is a waste heat recovery turbine system capable of lowering the temperature of hot water returned to a heat source and of suppressing a steaming phenomenon in a preheater without changing the flow rate of a heating medium flowing through an evaporator. The waste heat recovery turbine system comprises a turbine 4 driven by a working medium M, an evaporator 10 which evaporates the working medium M by heat exchange with a heating medium H supplied from a first heat source 20 a and supplies the evaporated working medium M to the turbine 4 , a preheater 12 for preheating the working medium M flowing into the evaporator 10 , a preheating passage 22 b through which the heating medium H is supplied from the evaporator 10 to the preheater 12 , a return passage 22 d which branches from a location of the preheating passage 22 b and serves to return the heating medium H to a second heat source 20 b , and a flow control valve 24 for controlling a flow rate of the heating medium H supplied to the preheater 12 by causing the heating medium H which has radiated heat in the evaporator 10 to flow through the return passage 22 d.

1 . A waste heat recovery turbine system comprising:
 a turbine driven by a working medium;   an evaporator which evaporates the working medium by heat exchange with a heating medium supplied from a heat source and supplies the evaporated working medium to the turbine;   a preheater for preheating the working medium flowing into the evaporator;   a preheating passage through which the heating medium is supplied from the evaporator to the preheater;   a return passage which branches from a location of the preheating passage and serves to return the heating medium to the heat source; and   a flow control mechanism for controlling a flow rate of the heating medium supplied to the preheater by causing the heating medium which has radiated heat in the evaporator to flow through the return passage.   
     
     
         2 . The waste heat recovery turbine system according to  claim 1 , wherein the flow control mechanism is provided in the return passage. 
     
     
         3 . The waste heat recovery turbine system according to  claim 1 , wherein the flow control mechanism is provided in the preheating passage, and the return passage branches from the preheating passage in a location upstream of the flow control mechanism. 
     
     
         4 . The waste heat recovery turbine system according to  claim 1 , further comprising:
 a temperature sensor for detecting a temperature of the working medium at an outlet of the preheater; and   a temperature control means configured to control the flow control mechanism so that the detected temperature does not exceed a predetermined value.   
     
     
         5 . The waste heat recovery turbine system according to  claim 1 ,
 wherein the preheater includes a shell and tubes inserted through an interior of the shell, the working medium being flowed through the tubes and the heating medium being flowed through the interior of the shell.   
     
     
         6 . The waste heat recovery turbine system according to  claim 2 , further comprising:
 a temperature sensor for detecting a temperature of the working medium at an outlet of the preheater; and   a temperature control means configured to control the flow control mechanism so that the detected temperature does not exceed a predetermined value.   
     
     
         7 . The waste heat recovery turbine system according to  claim 3 , further comprising:
 a temperature sensor for detecting a temperature of the working medium at an outlet of the preheater; and   a temperature control means configured to control the flow control mechanism so that the detected temperature does not exceed a predetermined value.   
     
     
         8 . The waste heat recovery turbine system according to  claim 2 ,
 wherein the preheater includes a shell and tubes inserted through an interior of the shell, the working medium being flowed through the tubes and the heating medium being flowed through the interior of the shell.   
     
     
         9 . The waste heat recovery turbine system according to  claim 3 ,
 wherein the preheater includes a shell and tubes inserted through an interior of the shell, the working medium being flowed through the tubes and the heating medium being flowed through the interior of the shell.   
     
     
         10 . The waste heat recovery turbine system according to  claim 4 ,
 wherein the preheater includes a shell and tubes inserted through an interior of the shell, the working medium being flowed through the tubes and the heating medium being flowed through the interior of the shell.   
     
     
         11 . The waste heat recovery turbine system according to  claim 6 ,
 wherein the preheater includes a shell and tubes inserted through an interior of the shell, the working medium being flowed through the tubes and the heating medium being flowed through the interior of the shell.   
     
     
         12 . The waste heat recovery turbine system according to  claim 7 ,
 wherein the preheater includes a shell and tubes inserted through an interior of the shell, the working medium being flowed through the tubes and the heating medium being flowed through the interior of the shell.