Natural gas liquid fractionation plant waste heat conversion to power using organic rankine cycle

Abstract

Certain aspects of a natural gas liquid fractionation plant waste heat conversion to power using Organic Rankine Cycle can be implemented as a system. The system includes a heating fluid circuit thermally coupled to multiple heat sources of a natural gas liquid (NGL) fractionation plant. The system includes a power generation system that includes an organic Rankine cycle (ORC), which includes (i) a working fluid that is thermally coupled to the heating fluid circuit to heat the working fluid, and (ii) an expander configured to generate electrical power from the heated working fluid. The system includes a control system configured to actuate a set of control valves to selectively thermally couple the heating fluid circuit to at least a portion of the multiple heat sources of the NGL fractionation plant.

1 . (canceled) 
     
     
         2 . A system, comprising:
 a heating fluid circuit configured to thermally couple a heating fluid to a plurality of heat sources of a hydrocarbon refining plant, the heating fluid circuit comprising a plurality of heat exchangers fluidly coupled in parallel;   an evaporator that thermally couples the heating fluid circuit to a working fluid to heat the working fluid with the heating fluid;   an expander configured to generate electrical power from the heated working fluid;   a condenser that thermally couples the working fluid to a condenser liquid supply fluid to cool the working fluid;   a heating fluid tank that fluidly couples the plurality of heat exchangers; and   a flow control system that comprises a set of control valves to selectively thermally couple the heating fluid to the plurality of heat sources of the hydrocarbon refining plant.   
     
     
         3 . The system of  claim 2 , further comprising conduits containing the working fluid and the working fluid comprises isobutane. 
     
     
         4 . The system of  claim 2 , wherein the heating fluid circuit further comprises pipes containing water or oil. 
     
     
         5 . The system of  claim 2 , further comprising at least one pump to circulate the working fluid through at least one of the evaporator, the condenser, or the heating fluid tank. 
     
     
         6 . The system of  claim 2 , further comprising at least one pump to circulate the condenser liquid supply fluid through the condenser. 
     
     
         7 . The system of  claim 2 , wherein the heating fluid circuit thermally couples the heating fluid to the plurality of heat sources in the plurality of heat exchangers. 
     
     
         8 . The system of  claim 7 , wherein the plurality of heat exchangers comprises a plurality of sets of heat exchangers, each set of heat exchangers comprising between one and five heat exchangers. 
     
     
         9 . The system of  claim 8 , wherein the plurality of sets of heat exchangers comprise:
 a first set of heat exchangers comprising two heat exchangers;   a second set of heat exchangers comprising five heat exchangers;   a third set of heat exchangers comprising four heat exchangers;   a fourth set of heat exchangers comprising one heat exchanger;   a fifth set of heat exchangers comprising three heat exchangers; and   a sixth set of heat exchangers comprising two heat exchangers.   
     
     
         10 . The system of  claim 9 , wherein the two heat exchangers of the first set of heat exchangers are thermally coupled to at least two ethane system heat sources, the five heat exchangers of the second set of heat exchangers are thermally coupled to at least five propane system heat sources, the four heat exchangers of the third set of heat exchangers are thermally coupled to at least four butane system heat sources, the one heat exchanger of the fourth set of heat exchangers is thermally coupled to at least one pentane system heat source, the three heat exchangers of the fifth set of heat exchangers are thermally coupled to at least three natural gasoline system heat sources, and the two heat exchangers of the sixth set of heat exchangers are thermally coupled to at least two solvent regeneration system heat sources. 
     
     
         11 . The system of  claim 2 , wherein the hydrocarbon refining plant comprises a natural gas liquid (NGL) fractionation plant. 
     
     
         12 . A method, comprising:
 circulating a heating fluid in a heating fluid circuit that comprises a plurality of heat exchangers fluidly coupled in parallel;   thermally coupling the heating fluid to a plurality of heat sources of a hydrocarbon refining plant in the plurality of heat exchangers;   circulating the heating fluid through an evaporator that thermally couples the heating fluid circuit to a working fluid to heat the working fluid with the heating fluid;   generating electrical power with an expander from the heated working fluid;   cooling the heated working fluid in a condenser that thermally couples the working fluid to a condenser liquid supply fluid;   circulating the cooled working fluid to a heating fluid tank that fluidly couples the plurality of heat exchangers; and   actuating, with a flow control system, a set of control valves to selectively thermally couple the heating fluid to the plurality of heat sources of the hydrocarbon refining plant.   
     
     
         13 . The method of  claim 12 , further comprising circulating the working fluid through conduits that contain the working fluid, and the working fluid comprises isobutane. 
     
     
         14 . The method of  claim 12 , further comprising circulating the heating fluid through pipes of the heating fluid circuit, and the heating fluid comprises water or oil. 
     
     
         15 . The method of  claim 12 , further comprising operating, with the flow control system, at least one pump to circulate the working fluid through at least one of the evaporator, the condenser, or the heating fluid tank. 
     
     
         16 . The method of  claim 12 , further comprising operating, with the flow control system, at least one pump to circulate the condenser liquid supply fluid through the condenser. 
     
     
         17 . The method of  claim 12 , further comprising operating, with the flow control system, at least one pump to circulate the heating fluid from the heating fluid tank to the plurality of heat exchangers. 
     
     
         18 . The method of  claim 12 , wherein the plurality of heat exchangers comprises a plurality of sets of heat exchangers, each set of heat exchangers comprising between one and five heat exchangers. 
     
     
         19 . The method of  claim 18 , wherein the plurality of sets of heat exchangers comprise:
 a first set of heat exchangers comprising two heat exchangers;   a second set of heat exchangers comprising five heat exchangers;   a third set of heat exchangers comprising four heat exchangers;   a fourth set of heat exchangers comprising one heat exchanger;   a fifth set of heat exchangers comprising three heat exchangers; and   a sixth set of heat exchangers comprising two heat exchangers.   
     
     
         20 . The method of  claim 19 , wherein the two heat exchangers of the first set of heat exchangers are thermally coupled to at least two ethane system heat sources, the five heat exchangers of the second set of heat exchangers are thermally coupled to at least five propane system heat sources, the four heat exchangers of the third set of heat exchangers are thermally coupled to at least four butane system heat sources, the one heat exchanger of the fourth set of heat exchangers is thermally coupled to at least one pentane system heat source, the three heat exchangers of the fifth set of heat exchangers are thermally coupled to at least three natural gasoline system heat sources, and the two heat exchangers of the sixth set of heat exchangers are thermally coupled to at least two solvent regeneration system heat sources. 
     
     
         21 . The method of  claim 12 , wherein the hydrocarbon refining plant comprises a natural gas liquid (NGL) fractionation plant.