초록 ▼

This invention relates to a process for cooling or liquefying a fluid product (e.g., natural gas) in a heat exchanger, the process comprising: flowing a fluid refrigerant through a set of refrigerant microchannels in the heat exchanger; and flowing the product through a set of product microchannels

This invention relates to a process for cooling or liquefying a fluid product (e.g., natural gas) in a heat exchanger, the process comprising: flowing a fluid refrigerant through a set of refrigerant microchannels in the heat exchanger; and flowing the product through a set of product microchannels in the heat exchanger, the product flowing through the product microchannels exchanging heat with the refrigerant flowing through the refrigerant microchannels, the product exiting the set of product microchannels being cooler than the product entering the set of product microchannels. The process has a wide range of applications, including liquefying natural gas.

대표청구항 ▼

The invention claimed is: 1. A process for cooling a fluid product in a heat exchanger, the process comprising: compressing a fluid refrigerant, expanding the fluid refrigerant and flowing the fluid refrigerant through a set of refrigerant microchannels in the heat exchanger; and flowing the produc

The invention claimed is: 1. A process for cooling a fluid product in a heat exchanger, the process comprising: compressing a fluid refrigerant, expanding the fluid refrigerant and flowing the fluid refrigerant through a set of refrigerant microchannels in the heat exchanger; and flowing the product through a set of product microchannels in the heat exchanger; the product flowing through the product microchannels exchanging heat with the refrigerant flowing through the refrigerant microchannels, the product exiting the set of product microchannels being at a temperature in the range from about-250째 C. to about 500째 C. and being cooler than the product entering the set of product microchannels. 2. The process of claim 1 wherein the heat exchanger is a two-stream heat exchanger. 3. The process of claim 1 wherein the heat exchanger is a three-stream heat exchanger. 4. The process of claim 1 wherein the heat exchanger is a multi-stream heat exchanger employing more than three streams. 5. The process of claim 1 wherein the refrigerant flowing through the refrigerant microchannels comprises a refrigerant flowing through a set of first microchannels in the heat exchanger and another refrigerant flowing through a set of second microchannels in the heat exchanger, the refrigerant flowing through the set of second microchannels having a different composition and/or being at a different temperature and/or pressure than the refrigerant flowing through the set of first microchannels. 6. The process of claim 1 wherein the flow of refrigerant through the refrigerant microchannels is non-turbulent. 7. The process of claim 1 wherein the refrigerant entering the refrigerant microchannels is at a pressure of up to about 2000 psig and a temperature of about-180 to about 100째 C. 8. The process of claim 1 wherein the refrigerant exiting the refrigerant microchannels is at a pressure of up to about 2000 psig and a temperature of about-180 to about 100째 C. 9. The process of claim 1 wherein the product entering the product microchannels is at a pressure of up to about 5000 psig and a temperature of about-40 to about 40째 C. 10. The process of claim 1 wherein the product exiting the product microchannels is at a pressure of up to about 5000 psig, and a temperature of about-170 to about-85째 C. 11. The process of claim 1 wherein the product flowing through the product microchannels is at a pressure in the range of about 500 to about 5000 psig. 12. The process of claim 1 wherein the pressure drop for the refrigerant flowing through the refrigerant microchannels is up to about 30 psi/ft. 13. The process of claim 1 wherein the product microchannels are adjacent to the refrigerant microchannels. 14. The process of claim 1 wherein the flow of refrigerant through the refrigerant microchannels is countercurrent relative to the flow of product through the product microchannels. 15. The process of claim 1 wherein the flow of refrigerant through the refrigerant microchannels is cross-current relative to the flow of product through the product microchannels. 16. The process of claim 1 wherein the flow of refrigerant through the refrigerant microchannels is co-current relative to the flow of product through the product microchannels. 17. The process of claim 5 wherein the refrigerant entering the set of first microchannels comprises a single phase vapor, a single phase liquid, or a mixture of vapor and liquid, the Reynolds Number for the flow of vapor refrigerant through the set of first microchannels being up to about 100,000 and the Reynolds Number for the flow of liquid refrigerant through the set of first microchannels being up to about 10, 000. 18. The process of claim 5 wherein the refrigerant entering the set of second microchannels comprises a mixture of vapor and liquid, the Reynolds Number for the flow of vapor refrigerant through the set of second microchannels being up to about 4000, and the Reynolds Number for the flow of liquid refrigerant through the set of second microchannels being up to about 4000. 19. The process of claim 1 wherein the refrigerant is compressed in a compressor and then cooled prior to flowing through the refrigerant microchannels. 20. The process of claim 5 wherein the refrigerant flows from the set of first microchannels through an expansion device to the set of second microchannels. 21. The process of claim 5 wherein the flow of refrigerant through the set of first microchannels is countercurrent relative to the flow of refrigerant through the set of second microchannels. 22. The process of claim 5 wherein the flow of refrigerant through the set of first microchannels is cocurrent relative to the flow of refrigerant through the set of second microchannels. 23. The process of claim 5 wherein the flow of refrigerant through the set of first microchannels is cross-current relative to the flow of refrigerant through the set of second microchannels. 24. The process of claim 5 wherein the refrigerant entering the set of first microchannels is at a pressure of up to about 2000 psig and a temperature of about-50 to about 100째 C. 25. The process of claim 5 wherein the refrigerant exiting the set of first microchannels is at a pressure of up to about 2000 psig and a temperature of about-180 to about 900째 C. 26. The process of claim 5 wherein the refrigerant entering the set of second microchannels is at a pressure of up to about 1000 psig and a temperature of about-180 to about-90째 C. 27. The process of claim 5 wherein the refrigerant exiting the set of second microchannels is at a pressure of up to about 1000 psig and a temperature of about-50 to about 100째 C. 28. The process of claim 5 wherein the product entering the set of third microchannels is at a pressure of up to about 5000 psig and a temperature of about-40 to about 40째 C. 29. The process of claim 5 wherein the product exiting the set of third microchannels is at a pressure of up to about 5000 psig, and a temperature of about-170 to about-85째 C. 30. The process of claim 5 wherein the pressure drop for the refrigerant flowing through the set of first microchannels is up to about 30 psi/ft, and the pressure drop for the refrigerant flowing through the set of second microchannels is up to about 30 psi/ft. 31. The process of claim 1 wherein the refrigerant comprises nitrogen, carbon dioxide, an organic compound containing 1 to about 5 carbon atoms per molecule, or a mixture of two or more thereof. 32. The process of claim 1 wherein the product comprises carbon dioxide, helium, nitrogen, argon, an organic compound containing 1 to about 5 carbon atoms per molecule, or a mixture of two or more thereof. 33. The process of claim 1 wherein the product entering the product microchannels comprises natural gas. 34. The process of claim 1 wherein the product exiting the product microchannels comprises liquefied natural gas. 35. The process of claim 1 wherein the product microchannels and refrigerant microchannels are constructed of a material comprising metal, ceramics, plastic, or a combination thereof. 36. The process of claim 1 wherein the refrigerant microchannels have internal dimensions of height of up to about 2 mm. 37. The process of claim 1 wherein the product microchannels have internal dimensions of height of up to about 2 mm. 38. The process of claim 1 wherein the refrigerant microchannels have lengths of up to about 10 meters. 39. The process of claim 1 wherein the product microchannels have lengths of up to about 10 meters. 40. The process of claim 1 wherein the coefficient of performance for the heat exchanger is at least about 0.5. 41. The process of claim 1 wherein the interstream planar heat transfer area percent for the refrigerant microchannels or the product microchannels is at least about 20%. 42. The process of claim 1 wherein the volumetric heat flux for the heat exchanger is at least about 0.5 W/cm3. 43. The process of claim 1 wherein the effectiveness of the heat exchanger is at least about 0.8. 44. The process of claim 1 wherein the product is cooled from a temperature of about 40째 C. to a temperature of about-160째 C., the rate of flow of product through the heat exchanger being at least about 1500 pounds per hour per cubic meter of the core volume of the heat exchanger. 45. The process of claim 44 wherein the pressure drop for the flow of refrigerant through the refrigerant microchannels is up to about 30 psi. 46. The process of claim 1 wherein the approach temperature for the heat exchanger is up to about 50째 C. 47. The process of claim 1 wherein the heat exchanger has a microchannel volume to heat exchanger volume ratio of at least about 0.2. 48. The process of claim 1 wherein micro-scale structures are formed on the interior surfaces of the refrigerant microchannels. 49. The process of claim 1 wherein the product exiting the product microchannels is advanced to another heat exchanger wherein the product is subjected to additional cooling, the another heat exchanger comprising another set of refrigerant microchannels and another set of product microchannels, another refrigerant flows through the another set of refrigerant microchannels, the product flows through the another set of product microchannels, the product flows through the another set of product microchannels exchanging heat with the another refrigerant flowing through the another set of refrigerant microchannels, the product exiting the another set of product microchannels being cooler than the product entering the another set of product microchannels. 50. The process of claim 49 wherein the product exiting the another set of product microchannels is advanced to a third heat exchanger wherein the product is subjected to additional cooling, the third heat exchanger comprising a third set of refrigerant microchannels and a third set of product microchannels, a third refrigerant flows through the third set of refrigerant microchannels, the product flows through the third set of product microchannels exchanging heat with the third refrigerant flowing through the third set of refrigerant microchannels, the product exiting the third set of product microchannels being cooler than the product entering the third set of product microchannels. 51. The process of claim 50 wherein the product is natural gas, the refrigerant is propane or propylene, the another refrigerant is ethane or ethylene, and the third refrigerant is methane. 52. The process of claim 1 wherein the product comprises natural gas, the natural gas flows through a series of microchannel heat exchangers to remove water, butanes or butylenes, propanes or propylene, and ethane or ethylene, from the natural gas prior to flowing the natural gas through the product microchannels. 53. The process of claim 1 wherein the walls of the product microchannels undergo a change in temperature of at least about 25째 C. per meter of length of the product microchannels in the direction of flow of product through the product microchannels. 54. The process of claim 1 wherein the heat exchanger is equipped with two or more sub-manifolds for supplying refrigerant and product to the microchannels and removing refrigerant and product from the microchannels. 55. The process of claim 1 wherein the heat exchanger is equipped with a header at the entrance to the microchannels, the refrigerant is in the form of a mixture of vapor and liquid, the vapor and liquid being mixed in the header. 56. The process of claim 1 wherein the refrigerant is in the form of a mixture of vapor and liquid, the vapor and liquid being mixed in the microchannels. 57. The process of claim 1 wherein the refrigerant flowing through the refrigerant microchannels, the product flowing through the product microchannels, or both the refrigerant flowing through the refrigerant microchannels and the product flowing through the product microchannels are at a pressure of at least about 1500 psig. 58. The process of claim 1 wherein an additional heat exchanger is positioned upstream of the heat exchanger, the product flowing through the additional heat exchanger prior to flowing through the product microchannels in the heat exchanger. 59. The process of claim 1 wherein an additional heat exchanger is positioned downstream of the heat exchanger, the product flows through the product microchannels in the heat exchanger and then flows through the additional heat exchanger. 60. The process of claim 49 wherein an additional heat exchanger is positioned between the heat exchanger and the another heat exchanger, the product flows through the product microchannels in the heat exchanger, then flows through the additional heat exchanger, and then flows through the another set of product microchannels in the another heat exchanger. 61. A process for cooling a fluid product in a heat exchanger, the process comprising: flowing a fluid refrigerant through a set of refrigerant microchannels in the heat exchanger, the refrigerant microchannels having lengths in the range from about 0.5 to about 10 meters; and flowing the product through a set of product microchannels in the heat exchanger, the product microchannels having lengths in the range from about 0.5 to about 10 meters; the product flowing through the product microchannels exchanging heat with the refrigerant flowing through the refrigerant microchannels, the product exiting the set of product microchannels being at a temperature in the range from about-250째 C. to about 500째 C. and being cooler than the product entering the set of product microchannels. 62. A process for cooling a fluid product in a heat exchanger, the process comprising: flowing a fluid refrigerant through a set of refrigerant microchannels in the heat exchanger; and flowing the product through a set of product microchannels in the heat exchanger; the product flowing through the product microchannels exchanging heat with the refrigerant flowing through the refrigerant microchannels, the product exiting the set of product microchannels being cooler than the product entering the set of product microchannels; the heat exchanger being equipped with a header at the entrance to the microchannels, the refrigerant being in the form of a mixture of vapor and liquid as it enters the refrigerant microchannels, the vapor and liquid being mixed in the header. 63. A process for cooling a fluid product in a heat exchanger, the process comprising: flowing a fluid refrigerant through a set of refrigerant microchannels in the heat exchanger, the refrigerant being in the form of a mixture of vapor and liquid, the vapor and liquid being mixed in the refrigerant microchannels; and flowing the product through a set of product microchannels in the heat exchanger; the product flowing through the product microchannels exchanging heat with the refrigerant flowing through the refrigerant microchannels, the product exiting the set of product microchannels being cooler than the product entering the set of product microchannels.