Exhaust heat recovery system

Abstract

An exhaust heat recovery system includes an exhaust pipe through which exhaust gas exhausted from an engine moves, a heat exchanger mounted in the exhaust pipe and inducing heat exchange between the exhaust gas and a working fluid flowing therein, a plurality of reservoirs supplying working fluids to the heat exchanger, and channel adjusting valves allowing any one of the plurality of reservoirs to be in communication with the heat exchanger.

What is claimed is: 
     
         1 . An exhaust heat recovery system comprising:
 an exhaust pipe through which an exhaust gas exhausted from an engine moves;   a heat exchanger mounted in the exhaust pipe and inducing heat exchange between the exhaust gas and a working fluid flowing therein;   a plurality of reservoirs supplying working fluids to the heat exchanger; and   channel adjusting valves allowing one of the plurality of reservoirs to be in communication with the heat exchanger.   
     
     
         2 . The exhaust heat recovery system according to  claim 1 , further comprising:
 a pump pressurizing the working fluids from the plurality of reservoirs and supplying the pressurized working fluids to the heat exchanger;   a turbine receiving an evaporated working refrigerant from the heat exchanger to generate electric power; and   a condenser receiving the working refrigerant from the turbine to recover heat of the working refrigerant.   
     
     
         3 . The exhaust heat recovery system according to  claim 2 , wherein the channel adjusting valves include:
 a first channel adjust valve provided in a first connection channel connecting a condenser outlet through which a liquid-phase working fluid is exhausted from the condenser and the plurality of reservoirs to each other; and   a second channel adjusting valve provided in a second connection channel connecting the plurality of reservoirs and the pump to each other.   
     
     
         4 . The exhaust heat recovery system according to  claim 1 , wherein each of the plurality of reservoirs is provided with a temperature sensor and a pressure sensor. 
     
     
         5 . The exhaust heat recovery system according to  claim 2 , further comprising a recuperator allowing heat of a working fluid transferred from the turbine to the condenser to be transferred to the working fluids supplied from the plurality of reservoirs to the heat exchanger. 
     
     
         6 . The exhaust heat recovery system according to  claim 5 , wherein the recuperator is mounted between a supply pipe connecting the pump and the heat exchanger to each other and a recovery pipe connecting the turbine and the condenser to each other. 
     
     
         7 . A method of operating an exhaust heat recovery system, comprising:
 measuring internal temperatures and pressures of a plurality of reservoirs through temperature sensors and pressure sensors included in the plurality of reservoirs;   deciding whether working fluids stored in the plurality of reservoirs are in a liquid phase or a gas phase; and   allowing reservoirs in which the liquid-phase working fluids are stored among the plurality of reservoirs and a pump to be in communication with each other.   
     
     
         8 . The method of operating the exhaust heat recovery system according to  claim 7 , wherein in a case in which all of the working fluids stored in the plurality of reservoirs are in the gas phase, an operation of the pump is stopped. 
     
     
         9 . The method of operating the exhaust heat recovery system according to  claim 7 , wherein when the number of reservoirs in which the liquid-phase working fluids are stored among the plurality of reservoirs is two or more, a reservoir set among the plurality of reservoirs and the pump are in communication with each other. 
     
     
         10 . The method of operating the exhaust heat recovery system according to  claim 7 , wherein at a time of initial start-up, a reservoir set among the plurality of reservoirs and the pump are in communication with each other.