Delayed coking plant combined heating and power generation
A system includes a heat exchange system and a power generation system. The heat exchange system includes first, second, and third heat exchangers each operable as a continuous source of heat from a delayed coking plant. The first and second heat exchangers heat first and second fluid streams to produce heated first and second fluid streams, respectively. The heated second fluid stream has a lower temperature and a greater quantity of heat than the heated first fluid stream. The third heat exchanger heats a third fluid stream to produce a heated third fluid stream that includes the heated first fluid stream and a hot fluid stream. The heated third fluid stream has a lower temperature than the heated first fluid stream. The power generation system generates power using heat from the heated second and third fluid streams.
1. A system comprising:
a heat exchange system comprising:
a first heat exchanger operable as a continuous source of heat from a delayed coking plant, the first heat exchanger configured to heat a first fluid stream to produce a heated first fluid stream;
a second heat exchanger operable as a continuous source of heat from the delayed coking plant, the second heat exchanger configured to heat a second fluid stream to produce a heated second fluid stream, wherein the heated second fluid stream has a lower temperature and a greater quantity of heat than the heated first fluid stream;
a third heat exchanger operable as a continuous source of heat to the delayed coking plant, the third heat exchanger configured to heat a third fluid stream to produce a heated third fluid stream, wherein the third fluid stream includes the heated first fluid stream and a hot fluid stream, wherein the heated third fluid stream has a lower temperature than the heated first fluid stream; and
a power generation system configured to generate power using heat from the heated second fluid stream and the heated third fluid stream.
2. The system of claim 1 , further comprising a fluid storage tank configured to receive an intermittent stream of hot fluid and to pass the hot fluid stream continuously.
3. The system of claim 2 , further comprising a fourth heat exchanger operable as an intermittent source of heat from the delayed coking plant, the fourth heat exchanger configured to heat a fourth fluid stream to produce the intermittent stream of hot fluid.
4. The system of claim 3 , wherein the intermittent hot stream has a greater quantity of heat and a lower temperature than the heated first fluid stream.
5. The system of claim 3 , wherein the fourth heat exchanger recovers heat from an output stream from a coker blowdown tower in the delayed coking plant, wherein the output stream is an intermittent heat source.
6. The system of claim 3 , wherein the heat exchange system comprises multiple fourth heat exchangers each configured to heat a portion of the intermittent fluid stream, wherein each fourth heat exchanger recovers heat from a corresponding intermittent heat source in the delayed coking plant.
7. The system of claim 1 , wherein the first heat exchanger recovers heat from a continuous heat source in the delayed coking plant, the continuous heat source having a temperature of at least about 134° C.
8. The system of claim 1 , wherein the first heat exchanger recovers heat from a bottom stream from a debutanizer in the delayed coking plant.
9. The system of claim 1 , wherein the first heat exchanger recovers heat from a stream output from a fractionator in the delayed coking plant.
10. The system of claim 1 , wherein the heat exchange system comprises multiple first heat exchangers each configured to heat a portion of the first fluid stream, wherein each first heat exchanger recovers heat from a corresponding continuous heat source in the delayed coking plant.
11. The system of claim 1 , wherein the second heat exchanger recovers heat from a continuous heat source in the delayed coking plant, the continuous heat source having a temperature of less than about 134° C.
12. The system of claim 1 , wherein the second heat exchanger recovers heat from an overhead stream from a fractionator in the delayed coking plant.
13. The system of claim 1 , wherein the second heat exchanger recovers heat from an inter-stage stream or a discharge stream of a coker gas compressor in the delayed coking plant.
14. The system of claim 1 , wherein the heat exchange system comprises multiple second heat exchangers each configured to heat a portion of the second fluid stream, wherein each second heat exchanger recovers heat from a corresponding continuous heat source in the delayed coking plant.
15. The system of claim 1 , wherein the temperature of the heated third fluid stream is less than the temperature of the third fluid stream.
16. The system of claim 1 , wherein the third heat exchanger is configured to heat a stripper bottom product from a stripper in the delayed coking plant by exchange with the third fluid stream.
17. The system of claim 1 , wherein the third heat exchanger is configured to heat a rich sponge oil stream from a sponge absorber in the delayed coking plant by exchange with the third fluid stream.
18. The system of claim 1 , wherein the heat exchange system comprises multiple third heat exchangers each configured to heat a corresponding stream in the delayed coking plant by exchange with a portion of the third fluid stream.
19. The system of claim 1 , wherein the power generation system comprises an Organic Rankine cycle system.
20. The system of claim 1 , wherein the system is integrated into the delayed coking plant as a retrofit to the delayed coking plant.
21. The system of claim 20 , wherein one or more existing heat exchangers in the delayed coking plant are no longer used following the retrofit.
22. The system of claim 20 , wherein, following the retrofit, the delayed coking plant uses up to about 13% less in heating utility consumption compared to the heating utility consumption of the delayed coking plant prior to the retrofit.
23. A method comprising:
heating a first fluid stream to produce a heated first fluid stream by exchange with a first continuous source of heat from a delayed coking plant;
heating a second fluid stream to produce a heated second fluid stream by exchange with a second continuous source of heat from the delayed coking plant, wherein the heated second fluid stream has a lower temperature and a greater quantity of heat than the heated first fluid stream;
heating a stream in the delayed coking plant by exchange with a third fluid stream to produce a heated third fluid stream, wherein the third fluid stream includes the heated first fluid stream and a hot fluid stream, wherein the heated third fluid stream has a lower temperature than the heated first fluid stream; and
generating power using heat from the heated second fluid stream and the heated third fluid stream.
24. The method of claim 23 , further comprising:
receiving an intermittent hot stream at a fluid storage tank; and
continuously passing the hot fluid stream from the fluid storage tank.
25. The method of claim 24 , further comprising heating a fourth fluid stream to produce the intermittent hot stream by exchange with an intermittent source of heat from the delayed coking plant.
26. The method of claim 25 , wherein heating the fourth fluid stream comprises heating the third fluid stream using heat recovered from an output stream from a coker blowdown tower in the delayed coking plant, wherein the output stream is an intermittent heat source.
27. The method of claim 23 , wherein heating the first fluid stream comprises heating the first fluid stream using heat recovered from a bottom stream from a debutanizer in the delayed coking plant.
28. The method of claim 23 , wherein heating the first fluid stream comprises heating the first fluid stream using heat recovered from a stream output from a fractionator in the delayed coking plant.
29. The method of claim 23 , wherein heating the second fluid stream comprises heating the second fluid stream using heat recovered from an overhead stream from a fractionator in the delayed coking plant.
30. The method of claim 23 , wherein heating the second fluid stream comprises heating the second fluid stream using heat recovered from an inter-stage stream and or a discharge stream of a coker gas compressor in the delayed coking plant.
31. The method of claim 23 , wherein heating a stream in the delayed coking plant comprises heating a stripper bottom product from a stripper in the delayed coking plant.
32. The method of claim 23 , wherein heating a stream in the delayed coking plant comprises heating a rich sponge oil stream from a sponge absorber in the delayed coking plant.
33. The method of claim 23 , wherein generating power comprises generating power using an Organic Rankine cycle system.
34. The method of claim 23 , wherein generating power comprises generating at least about 9 MW of power.
35. The method of claim 23 , further comprising returning the heated second fluid stream and the heated third fluid stream to an accumulation tank.