Supplemental heating in waste heat recovery

Abstract

A waste heat recovery apparatus, for use with an internal combustion engine, includes a working fluid circuit to circulate working fluid, a boiler connected on the working fluid circuit and adapted to recover waste heat from a source to heat working fluid, and an expander connected on the working fluid circuit to receive working fluid from the boiler. A supplemental heating arrangement is connected on the working fluid circuit to selectively heat the working fluid when recovered waste heat is not sufficient to heat the working fluid to an operating temperature for the expander.

1 . A waste heat recovery apparatus, comprising:
 a working fluid circuit to circulate working fluid;   a boiler connected on the working fluid circuit and adapted to recover waste heat from a source and transfer recovered waste heat to the working fluid;   an expander connected on the working fluid circuit to receive working fluid from the boiler; and,   a supplemental heating arrangement connected to deliver heat to the working fluid.   
     
     
         2 . The waste heat recovery apparatus of  claim 1 , comprising:
 a temperature sensor disposed to sense a temperature of the working fluid at an exit of the boiler and generate a temperature signal representative thereof; and,   a controller connected to receive the temperature signal from the temperature sensor and connected to control the heating arrangement responsive to the temperature signal.   
     
     
         3 . The waste heat recovery apparatus of  claim 1 , comprising an energy source connected to deliver energy to the heating arrangement. 
     
     
         4 . The waste heat recovery apparatus of  claim 1 , comprising a burner in the heating arrangement. 
     
     
         5 . The waste heat recovery apparatus of  claim 1 , comprising an electric heater in the heating arrangement. 
     
     
         6 . The waste heat recovery apparatus of  claim 1 , wherein, the supplemental heating arrangement is connected to the working fluid circuit between the boiler and the expander. 
     
     
         7 . The waste heat recovery apparatus of  claim 1 , wherein, the supplemental heating arrangement is connected to the working fluid circuit between the pump and the boiler. 
     
     
         8 . The waste heat recovery apparatus of  claim 1 , wherein, the supplemental heating arrangement is connected to deliver heat to the boiler. 
     
     
         9 . The waste heat recovery apparatus of  claim 1 , comprising:
 a temperature sensor disposed to sense a temperature of the working fluid at an exit of the supplemental heating arrangement and generate a temperature signal representative thereof; and,   a controller connected to receive the temperature signal from the temperature sensor and connected to control the heating arrangement responsive to the temperature signal.   
     
     
         10 . The waste heat recovery apparatus of  claim 1 , comprising a bypass valve and bypass circuit connected on the working fluid circuit to selectively direct working fluid to bypass the expander. 
     
     
         11 . The waste heat recovery apparatus of  claim 10 , wherein the supplemental heating arrangement is connected in the working fluid circuit between the boiler and the bypass valve. 
     
     
         12 . The waste heat recovery apparatus of  claim 10 , comprising a second bypass valve, the bypass circuit comprising a first circuit wherein working fluid flows is directed by the first bypass valve to the second bypass valve then by the second bypass valve to the expander and a second bypass circuit wherein working fluid is directed by the first bypass valve to the second bypass valve then by the second bypass valve to bypass the expander. 
     
     
         13 . The waste heat recovery apparatus of  claim 12 , wherein the supplemental heating arrangement is disposed on the first circuit. 
     
     
         14 . The waste heat recovery apparatus of  claim 1 , comprising a valve connected on the working fluid circuit to selectively direct working fluid to one of the expander or to a heating loop, wherein the supplemental heating arrangement is disposed on the heating loop.