TWI618792B - Processes and compositions for organic rankine cycles for generating mechanical energy from heat - Google Patents

Abstract

This paper discloses a composition of a novel working fluid that is uniquely designed to achieve higher cycle efficiency and thus higher overall system efficiency. In particular, such working fluids can be used in an organic Rankine cycle system for efficiently converting heat from any heat source into mechanical energy. The present invention also relates to a novel process for recovering heat from a heat source using an ORC system containing a novel working fluid, wherein the novel working fluid comprises at least about 20 weight percent of cis-1,1,1,4,4,4-hexafluoro-2. Butene (HFO-1336mzz-Z), trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzzE) or a mixture thereof.

Description

Process and composition for an organic Rankine cycle for generating mechanical energy from heat

The present invention relates generally to a novel working fluid that is uniquely designed to reduce the effects of climate change and achieve higher cycle efficiencies, thereby achieving higher overall system efficiency. In particular, these working fluids can be used in organic Rankine cycle (ORC) systems for efficiently converting heat from various heat sources into mechanical energy. The present invention also relates to a novel process for recovering heat from a heat source using an ORC system containing a novel working fluid, wherein the novel working fluid comprises at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2 Butene (HFO-1336mzz-Z), trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or a mixture thereof.

Previous Rankine cycle systems have used various working fluids containing flammable or combustible working fluids, such as fluids with relatively high toxicity, fluids with a relatively high global warming potential (GWP), and ozone depletion potential (ODP). Zero fluid. The industry is already working to replace the ozone-depleting CFCs and hydrochlorofluorocarbons (HCFCs). Langken cycle applications are extremely promising for working fluids that are non-flammable, less toxic, and environmentally sustainable.

It has been discovered that the novel working fluid of the present invention surprisingly provides a high degree of cycle efficiency in an ORC system, thereby achieving a higher overall system efficiency in the power cycle while being low toxicity, non-flammable, zero ODP and very low GWP.

In one embodiment, the invention is directed to a process for recovering heat from a heat source and generating mechanical energy, comprising the steps of: (a) passing a first working fluid of the liquid phase through a heat exchanger or an evaporator, wherein The heat exchanger or the evaporator is in communication with the heat source supplying heat; (b) removing at least a portion of the vapor phase of the first working fluid from the heat exchanger or the evaporator; (c) the at least a portion of the vapor phase The first working fluid is transferred to an expander, wherein at least a portion of the heat is converted to mechanical energy; (d) the at least a portion of the vapor phase of the first working fluid is transferred from the expander to a condenser, wherein At least a portion of the vapor phase of the first working fluid is condensed into a liquid phase of a second working fluid; (e) selectively compressing and mixing the liquid phase of the second working fluid and the liquid phase of step (a) a working fluid; and (f) selectively repeating steps (a) through (e) at least once; wherein at least about 20 weight percent of the first working fluid comprises HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof .

More particularly, the invention relates to a process for recovering heat from a heat source and generating mechanical energy, comprising the steps of: (a) compressing a first working fluid of the liquid phase above a critical pressure of the first working fluid; (b) causing the steps The first working fluid of (a) passes through a heat exchanger or a fluid heater and heats the first working fluid to a temperature above or below a critical temperature of the first working fluid, wherein the heat exchanger or The fluid heater is in communication with the heat source that supplies heat; (c) removing at least a portion of the heated first working fluid from the heat exchanger or the fluid heater; (d) transferring the at least a portion of the heated first working fluid to an expander; at least a portion of The heat is converted into mechanical energy, and wherein the pressure of the at least a portion of the heated first working fluid is reduced below a critical pressure of the first working fluid, thereby causing the at least a portion of the first work to be heated The fluid becomes a first working fluid vapor or a vapor and liquid mixture of a first working fluid; (e) transferring the first working fluid vapor or the vapor and liquid mixture of the first working fluid from the expander to a condenser Wherein the at least a portion of the working fluid vapor or the vapor and liquid mixture of the working fluid is completely condensed into a second working fluid in the liquid phase; (f) selectively compressing and mixing the second working fluid of the liquid phase and The first working fluid of the liquid phase in step (a); (g) selectively repeating steps (a) through (f) at least once; wherein at least about 20 weight percent of the first working fluid comprises HFO-1336 mzz-Z, HFO-1336mzz-E or a mixture thereof.

In one embodiment, the invention is more directed to a composition comprising HFO-1336mzz-Z having a temperature in the range of from about 250 ° C to about 300 ° C, wherein the HFO-1336mzz-Z is present in an amount of from about 50 weight percent to Within 99.5 weight percent range.

In yet another embodiment, the present invention is directed to an organic Rankine cycle for extracting heat at operating pressures ranging from about 3 MPa to about 10 Mpa. A system wherein about 20 weight percent of the working fluid comprises HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof.

In another embodiment, the present invention is directed to a composition as a working fluid for power cycling, wherein the temperature of the composition is in the range of from about 50 ° C to about 400 ° C, and wherein about 20 percent by weight The composition comprises HFO-1336mzz-Z, HFO-1336mzz-E or a mixture thereof.

In another embodiment, the invention is directed to a method of replacing HFC-245fa in a power cycle system. The method includes removing the HFC-245fa from the power cycle system and filling the system with a working fluid comprising HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof.

The Global Warming Potential (GWP) is an index that assesses the relative global warming contribution of atmospheric emissions of one kilogram of specific greenhouse gases based on one kilogram of carbon dioxide emissions. By calculating the GWP for different time horizons, you can understand the effect of a particular gas remaining in the atmosphere. The GWP is usually referenced over a hundred years.

The net cycle power output is the mechanical work rate at the expander (eg, turbine) minus the mechanical power consumed by the compressor (eg, the liquid pump).

The volume of the power cycle is the net cycle power output per unit volume of the working fluid circulating in the cycle (measured at the outlet of the expander).

Cycle efficiency (also known as thermal efficiency) is the net cycle power output divided by the heat ratio accepted by the working fluid during the heating phase.

Subcooling is a decrease in the temperature of the liquid below a saturation point of the liquid at a certain pressure. The saturation point is the temperature at which the vapor composition completely condenses into a liquid (also known as a bubble point). However, too cold continues to cool the liquid to a lower temperature liquid at a certain pressure. The amount of subcooling is a cooling amount (in degrees) below the saturation temperature or a liquid composition is cooled to a level below its saturation temperature.

Overheating is a term that defines the extent to which a vapor composition is heated above its saturation temperature (the temperature at which the first drop of liquid is formed, also referred to as the "dew point" if the composition is cooled).

Temperature glide (sometimes simply referred to as "slip") is the absolute difference between the start and end temperatures of a refrigerant in a component of a refrigerant system and excludes any supercooling or overheat. This term can be used to describe the condensation or evaporation of a near azeotropic or non-azeotropic composition. Average slip is the average of the slip in the condenser of a particular refrigeration system operating under a particular set of conditions and the slip in the evaporator.

The term "dry", for example as used in "dry expansion", means an expansion that occurs entirely in the vapor phase and is free of the presence of a liquid working fluid. Therefore, the "dry" used in this article does not relate to the presence or absence of water.

An azeotropic composition is a mixture of two or more different components which, when in a liquid form at a particular pressure, boils at a substantially fixed temperature which may be higher or lower than the boiling of the individual components. The temperature, and will provide a vapor composition substantially the same as the bulk liquid composition in which the boiling occurs. (See for example M.F. Doherty and M.F. Malone, Conceptual Design of Distillation Systems, McGraw-Hill (New York), 2001, 185-186, 351-359).

Therefore, the main feature of the azeotropic composition is that the boiling point of the liquid composition is fixed at a specific pressure, and the vapor composition above the boiling composition is substantially an integral boiling liquid composition (ie, no liquid composition occurs) Fractionation of components). As also recognized in the art, as the azeotrope boils at different pressures, the boiling point and weight percentage of each component may vary. Thus, the azeotrope composition can be defined by the exact weight percentage of the components of the composition having a fixed boiling point at a particular pressure, or as defined by the compositional range of the components, or as defined by the unique relationship between the components. .

For the purposes of the present invention, a class of azeotrope compositions means a composition that behaves substantially like an azeotrope composition (i.e., has a fixed boiling character or has a tendency to not fractionate upon boiling or evaporation). Therefore, if there is any change in the vapor and liquid composition during boiling or evaporation, the change is only minimal or negligible. This vapor and liquid composition can be contrasted when the non-azeotrope composition is boiled or evaporated.

The terms "comprising," "comprising," "having," or "said" or "comprising", as used herein, are intended to encompass non-exclusive inclusions. For example, a set of compounds, processes, methods, articles, or devices containing the plural elements listed in the list are not necessarily limited to the elements listed in the list, but may include, but not explicitly listed, Process, method, article or other element inherent in the device. In addition, unless expressly stated to the contrary, “or” is an inclusive “or” rather than an exclusive “or”. For example, any of the following conditions satisfies condition A or B: A is true (or exists) and B is false (or non-existent), A is false (or non-existent) and B is real (or existing), and A and B are real (or exist).

The conjunction "consisting of" excludes any element, step or component that is not specifically described. If used in the scope of patent application, in addition to the impurities normally associated with it, this language should limit the scope of the patent application to the scope of the materials listed. When the phrase "consisting of" appears in the clause of the subject matter in the scope of the patent application, rather than directly following the preface, it only limits the elements in the clause; other elements are not excluded from the scope of the patent application. .

The word "consisting essentially of" is used to define a composition, method or device that includes materials, steps, features, components or elements other than those disclosed in the text, provided that such additional The materials, steps, features, components or elements do have a substantial impact on the basic and novel features of the invention. The term "mainly composed" is between "contains" and "contains".

If the applicant defines an invention or part thereof in an open-ended language such as "including", it means that (unless otherwise stated) the description should be construed as describing the invention as "mainly composed" or "consisting of".

Also, "a" or "an" is used to describe the elements and components described herein. This is done for convenience only and provides a general sense of the scope of the invention. This description should be understood to include one or at least one, and the singular also includes the plural.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning The meaning is the same. Although methods or materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, suitable methods and materials are still described below. All publications, patent applications, patents, and other references mentioned herein are hereby incorporated by reference in their entirety in their entirety in the entirety of the disclosure. In the event of a conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting.

E-1,1,1,4,4,4-hexafluoro-2-butene (also known as HFO-1336mzz-E or anti-HFO-1336mzz, and having the structure of E-CF ₃ CH=CHCF ₃ ) And Z-1,1,1,4,4,4-hexafluoro-2-butene (also known as HFO-1336mzz-Z or cis-HFO-1336mzz, and having a structure of Z-CF ₃ CH=CHCF ₃ ) can be produced by methods known in the art, such as hydrodechlorination of 2,3-dichloro-1,1,1,4,4,4-hexafluoro-2-butene, such as U.S. Patent Application The invention is described in US 2009/0012335 A1, which is incorporated herein by reference.

Process for recovering heat or converting heat into mechanical energy

For the purposes of the present invention, a transcritical organic Rankine cycle is defined as an organic Rankine cycle that extracts heat at a pressure above the critical pressure of the working fluid used in the cycle.

In one embodiment, the present invention is directed to a novel process for recovering heat from a heat source and generating mechanical energy using an organic Rankine cycle (ORC) system utilizing a novel working fluid.

In one embodiment, the foregoing process for recovering heat from a heat source and generating mechanical energy comprises the steps of: (a) passing a first working fluid of the liquid phase through a heat exchanger or an evaporator, wherein the heat exchanger or the evaporator is in communication with the heat source supplying heat; (b) from the heat exchanger or the evaporation Removing at least a portion of the vapor phase of the first working fluid; (c) transferring the at least a portion of the vapor phase of the first working fluid to an expander, wherein at least a portion of the heat is converted to mechanical energy; (d) The first working fluid of the at least a portion of the vapor phase is transferred from the expander to a condenser, wherein the first working fluid of the at least a portion of the vapor phase is condensed into a second working fluid in the liquid phase; (e) selective Compressing and mixing the second working fluid of the liquid phase and the first working fluid of the liquid phase in step (a); and (f) selectively repeating steps (a) through (e) at least once; wherein at least about 20 The weight percent of the first working fluid comprises HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the first working fluid comprises at least 30 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the first working fluid comprises at least 40 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the first working fluid comprises at least 50 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof.

The aforementioned working fluid comprises at least about 20 weight percent of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or at least about 20 weight percent of trans-1 1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of a mixture thereof. In another embodiment, the working fluid comprises at least about 30 weights Percentage of HFO-1336mzz-Z, HFO-1336mzz-E or mixtures thereof. In another embodiment, the working fluid comprises at least 40 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the working fluid comprises at least 50 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In a suitable embodiment, the at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or the at least about 20 weight percent The trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or the mixture of at least about 20 weight percent is selected from the following percentages of the working fluid. : about 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 50.5, 51, 52, 52.5, 53, 53.5, 54, 54.5, 55, 55.5, 56, 56.5, 57, 57.5, 58, 58.5, 59, 59.5, 60, 60.5, 61, 61.5, 62, 62.5, 63, 63.5, 64, 64.5, 65, 65.5, 66, 66.5, 67, 67.5, 68, 68.5, 69, 69.5, 70, 70.5, 71, 71.5, 72, 72.5, 73, 73.5, 74, 74.5, 75, 55.5, 76, 76.5, 77, 77.5, 78, 78.5, 79, 79.5, 80, 80.5, 81, 81.5, 82, 82.5, 83, 83.5, 84, 84.5, 85, 85.5, 86, 86.5, 87, 87.5, 88, 88.5, 89, 89.5, 90, 90.5, 91, 91.5, 92, 92.5, 93, 93.5, 94, 94.5, 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99, 99.5 and about 100%.

In another suitable embodiment, the at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or the About 20% by weight of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20% by weight of the mixture thereof is selected from the foregoing The range defined by the two percentage values (endpoints are included).

In an embodiment of the foregoing process, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 10 weight percent HFO-1336mzz-E and 90 or more weight percent HFO-1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 15 weight percent HFO-1336mzz-E and 85 or more weight percent HFO -1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 20 weight percent HFO-1336mzz-E and 80 or more weight percent HFO -1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 25 weight percent HFO-1336mzz-E and 75 or more weight percent HFO -1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising from about 25 weight percent to about 75 weight percent HFO-1336mzz-E and about 75 weight percent Up to about 25 weight percent of HFO-1336mzz-Z.

The working fluid may also comprise less than about 80 weight percent of one or more other components selected from the group consisting of: cis-HFO-1234ze, anti-HFO-1234ze, HFO-1234yf, HFO-1234ye-E or Z , HFO 1225ye (Z), HFO-1225ye (E), HFO-1225yc, HFO-1243zf (3,3,3-trifluoropropene), HFO-1233zd-E or Z, HFO-1233xf, CF ₃ CH=CHCF ₃ (E), (CF ₃ ) ₂ CFCH=CHF(E & Z), (CF ₃ ) ₂ CFCH=CF ₂ , CF ₃ CHFC=CHF(E & Z), (C ₂ F ₅ )(CF ₃ ) C=CH ₂ , HFC-245fa, HFC-245eb, HFC-245ca, HFC-245cb, HFC-227ea, HFC-236cb, HFC-236ea, HFC-236fa, HFC-365mfc, HFC-43-10mee, CHF ₂ - O--CHF ₂ , CHF ₂ -O-CH ₂ F, CH ₂ FO-CH ₂ F, CH ₂ FO-CH ₃ , cyclo-CF ₂ -CH ₂ -CF ₂ -O, ring-CF ₂ -CF ₂ -CH ₂ -O, CHF ₂ -O--CF ₂ -CHF ₂ , CF ₃ -CF ₂ -O-CH ₂ F, CHF ₂ -O-CHF-CF ₃ , CHF ₂ -O-CF ₂ -CHF ₂ , CH ₂ FO-CF ₂ -CHF ₂ , CF ₃ -O-CF ₂ -CH ₃ , CHF ₂ -CHF-O-CHF ₂ , CF ₃ -O-CHF-CH ₂ F, CF ₃ -CHF-O- CH ₂ F, CF ₃ -O-CH ₂ -CHF ₂ , CHF ₂ -O-CH ₂ -CF ₃ , CH ₂ F-CF ₂ -O-CH ₂ F, CHF ₂ -O-CF ₂ -CH ₃ , CHF ₂ -CF ₂ -O-CH ₃ , CH ₂ FO-CHF--CH ₂ F, CHF ₂ -C HF-O-CH ₂ F, CF ₃ -O-CHF-CH ₃ , CF ₃ -CHF-O-CH ₃ , CHF ₂ -O-CH ₂ -CHF ₂ , CF ₃ -O-CH ₂ -CH ₂ F , CF ₃ -CH ₂ -O-CH ₂ F, CF ₂ H-CF ₂ -CF ₂ -O-CH ₃ , propane, cyclopropane, butane, isobutane, n-pentane, isopentane, neopentane Alkanes, cyclopentane, n-hexane, isohexane, heptane, trans-1,2-dichloroethylene and mixtures thereof with cis-HFO-1234ze and HFC-245fa.

In an embodiment, the working fluid comprises 80% by weight or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 70 weight percent or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 60 weight percent or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 50 weight percent or less of at least one of the foregoing compounds.

In an embodiment, the working fluid used to extract heat may be comprised of HFO-1336mzz-Z. In another embodiment, the working fluid used to extract heat may be comprised of HFO-1336mzz-E. In another embodiment, the working fluid used to extract heat may be comprised of a mixture of HFO-1336mzz-Z and HFO-1336mzz-E.

It should be noted that although the working fluid in the foregoing process description is referred to as a "first" working fluid and a "second" working fluid, it should be understood that the difference between the two working fluids is only that the first working fluid is entering the ORC. The fluid of the system, and the second working fluid is the fluid that enters the ORC system after at least one step of the preceding process.

In an embodiment of the foregoing process, the efficiency (cycle efficiency) of converting heat to mechanical energy is at least about 7%. In a suitable embodiment, the efficiency can be selected by the following: about 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5 and about 25%.

In another embodiment, the efficiency is selected from the range of endpoints (inclusive) as a range of any two efficiency values. Should understand the ORC system The instantaneous efficiency of the system can vary at any particular time depending on, for example, the source temperature and the pressure of the working fluid and its temperature.

In one embodiment of the foregoing process, the working fluid is HFO-1336mzz-Z having a very small amount of other components, and the evaporator operating temperature (the highest temperature at which the working fluid extracts heat) is less than or equal to about 171 °C. In a suitable embodiment, the operating temperature can be any of the following temperatures or within a range defined by any two of the following values (end points are included): about 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162 and about 163, 164 , 165, 166, 167, 168, 169, 170 and about 171 ° C.

In one embodiment of the foregoing process, the working fluid is primarily HFO-1336mzz-E and the evaporator operating temperature (the highest temperature at which the working fluid extracts heat) is less than or equal to about 137 °C. In a suitable embodiment, the operating temperature can be any of the following temperatures or within a range defined by any two of the following values (endpoints are included): About 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109 , 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134 , 135, 136 and about 137 ° C.

In another embodiment, the working fluid is a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, and the evaporator operating temperature (the highest temperature at which the working fluid extracts heat) is between about 137 ° C and about 171 ° C. Within the scope.

In an embodiment of the foregoing process, the evaporator operating pressure is less than about 2.5 MPa. In a suitable embodiment, the operating pressure can be any of the following pressures or within a range defined by any two of the following values (end points are included): about 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45 and About 2.50 MPa.

In an embodiment of the foregoing process, the working fluid has a GWP of less than 35. In a suitable embodiment, the GWP can be any of the following values or within a range defined by any of the following two values (endpoints are included): 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5 and about 35.

Figure 1 shows a schematic diagram of an embodiment of an ORC system for using heat from a heat source. A heat supply heat exchanger 40 transfers heat supplied from a heat source 46 to a working fluid entering the liquid phase of the heat supply heat exchanger 40. The heat supply heat exchanger 40 is in thermal communication with a heat source (which may be in direct contact or otherwise). In other words, the heat supply heat exchanger 40 receives thermal energy from the heat source 46 by any known heat transfer means. The ORC system working fluid circulates through the heat supply heat exchanger 40 to obtain thermal energy. At least a portion of the liquid working fluid is converted to vapor in the heat supply heat exchanger (in some instances, an evaporator) 40.

The working fluid, now in vapor form, is routed to an expander 32 where the expansion process from the heat source causes at least a portion of the thermal energy supplied from the heat source to be converted to mechanical energy, typically shaft energy. The shaft power can be used for any mechanical work by using a conventionally configured belt, pulley, gear, transmission or the like depending on the desired speed and the required torque. In an embodiment, the shaft may also be coupled to an electrodynamic generating device 30 such as an induction generator. The generated power can be used locally or transmitted to the grid.

The working fluid exiting the expander 32 is still in vapor form and continues to the condenser 34 where sufficient heat is removed to cause the fluid to condense into a liquid.

It is also desirable to have a liquid buffer tank 36 between the condenser 34 and the pump 38 to ensure that the working fluid in liquid form is adequately supplied to the pump suction. The working fluid in liquid form flows to a pump 38 which increases the pressure of the fluid so that the fluid can be directed back to the heat supply heat exchanger 40, thus completing the Rankine cycle.

In another embodiment, a second heat exchange loop that operates between the heat source and the ORC system can also be used. In Figure 2, an organic Rankine cycle system is shown using a second heat exchange loop. The operation of the main organic Rankine cycle is as described in Figure 1 above. The second heat exchange loop shown in Figure 2 operates as follows: heat from heat source 46' is delivered to heat supply heat exchanger 40' using a heat transfer medium (i.e., a second heat exchange loop fluid). The heat transfer medium moves from the heat supply heat exchanger 40' to a pump 42' where the pump 42' pumps the heat transfer medium back to the heat source 46'. This configuration provides another means of removing heat from the heat source and transferring it to the ORC system. This configuration provides flexibility by promoting the use of various fluids for sensible heat transfer. In fact, the working fluid of the present invention can be used as a second heat exchange loop fluid if the pressure within the loop is maintained at a fluid saturation pressure greater than or equal to the fluid temperature within the loop. In another aspect, the working fluid of the present invention can be used as a second heat exchange loop fluid or hot carrier fluid to extract heat from a heat source in an operational mode, wherein the working fluid can evaporate during the heat exchange process thereby generating a large fluid The difference in density is sufficient to maintain fluid flow (thermosiphon effect). Additionally, high boiling fluids such as glycol, brine, polyoxane or other substantially non-volatile fluids may be used as sensible heat transfer in the second loop configuration. The high boiling fluid may be a fluid having a boiling point of 150 ° C or higher. The second heat exchange loop makes maintenance of the heat source or ORC system easier because the two systems can be more easily isolated or separate. This approach simplifies heat exchanger design as compared to a heat exchanger having a high mass flow/low heat flux portion followed by a high heat flux/low mass flow portion.

Organic compounds usually have an upper temperature limit above which thermal decomposition occurs. The onset of thermal decomposition is related to the specific structure of the chemical and therefore will vary for different compounds. In order to be able to utilize a high temperature source for direct heat exchange via a working fluid, the aforementioned heat flux and mass flow design considerations can be used to promote heat exchange while maintaining the working fluid below its thermal decomposition onset temperature. Direct heat exchange in such situations often requires additional engineering and mechanical features and therefore increases costs. In this case, the second loop is designed to promote the utilization of high temperature heat sources by temperature control while avoiding the problems caused by direct heat exchange.

Other ORC system components for the second heat exchange loop embodiment are substantially identical to those described in FIG. As shown in Fig. 2, a liquid pump 42' circulates a second fluid (e.g., a heat transfer medium) in a second loop, and a portion of the second fluid entering the loop in the heat source 46' thereby obtains heat. The fluid then passes through a heat exchanger 40' wherein the second fluid releases heat to the ORC working fluid at heat exchanger 40'.

In yet another embodiment, the present invention is directed to a novel working fluid that is uniquely designed for higher cycle efficiency in a power cycle, thereby resulting in higher overall system efficiency. In particular, these working fluids are beneficial to organic Rankine Cycle (ORC) systems for efficiently converting the heat of various heat sources into mechanical energy. This workflow system is described before.

Transcritical organic Langken cycle

In one embodiment, the organic Rankine cycle is a transcritical cycle. Accordingly, the present invention is directed to a process for recovering heat from a heat source comprising the steps of: (a) compressing a first working fluid of the liquid phase above a critical pressure of the first working fluid; (b) causing the step ( a) the first working fluid passes through a heat exchanger or a fluid heater and heats the first working fluid to a temperature above or below a critical temperature of the first working fluid, wherein the heat exchanger or the a fluid heater in communication with the heat source supplying heat; (c) removing at least a portion of the heated first working fluid from the heat exchanger or the fluid heater; (d) the at least a portion of the heated portion a working fluid is transferred to an expander; wherein at least a portion of the heat is converted to mechanical energy, and wherein a pressure of the at least a portion of the heated first working fluid is reduced to a lower pressure than the first working fluid Dissolving the at least a portion of the heated first working fluid as a first working fluid vapor or a first working fluid vapor and liquid mixture; (e) the first working fluid vapor or the first working fluid The vapor-liquid mixture is transferred from the expander to a condenser, wherein the at least a portion of the working fluid vapor or the vapor-liquid mixture of the working fluid is completely condensed into a second working fluid in the liquid phase; (f) selective And compressing and mixing the second working fluid of the liquid phase and the first working fluid of the liquid phase in step (a); (g) selectively repeating steps (a) to (f) at least once; Wherein at least about 20 weight percent of the first working fluid comprises HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the first working fluid comprises at least 30 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the first working fluid comprises at least 40 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the first working fluid comprises at least 50 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof.

In an embodiment of the foregoing process, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 10 weight percent HFO-1336mzz-E and 90 or more weight percent HFO-1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 15 weight percent HFO-1336mzz-E and 85 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 20 weight percent HFO-1336mzz-E and 80 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 25 weight percent HFO-1336mzz-E and 75 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising from about 25 weight percent to about 75 weight percent HFO-1336mzz-E and about 75 weight percent to about 25 weight percent HFO-1336mzz-Z.

In one embodiment of the foregoing process, the efficiency (cycle efficiency) of converting heat to mechanical energy is at least about 7%. In a suitable embodiment, the efficiency can be selected by the following: about 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5 and about 25%.

In another embodiment, the efficiency is selected from the range of endpoints (inclusive) as a range of any of the foregoing efficiency values.

The aforementioned working fluid comprises at least about 20 weight percent of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or at least about 20 weight percent of trans-1,1 1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of a mixture thereof. In a suitable embodiment, the at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or the at least about 20 weight percent The trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or the mixture of at least about 20 weight percent is selected from the following percentages of working fluid: About 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44 45, 46, 47, 48, 49, 50, 50.5, 51, 52, 52.5, 53, 53.5, 54, 54.5, 55, 55.5, 56, 56.5, 57, 57.5, 58, 58.5, 59, 59.5, 60 , 60.5, 61, 61.5, 62, 62.5, 63, 63.5, 64, 64.5, 65, 65.5, 66, 66.5, 67, 67.5, 68, 68.5, 69, 69.5, 70, 70.5, 71, 71.5, 72, 72.5, 73, 73.5, 74, 74.5, 75, 55.5, 76, 76.5, 77, 77.5, 78, 78.5, 79, 79.5, 80, 80.5, 81, 81.5, 82, 82.5, 83, 83.5, 84, 84.5, 85, 85.5, 86, 86.5, 87, 87.5, 88, 88.5, 89, 89.5, 90, 90.5, 91, 91.5, 92, 92.5, 93, 93.5, 94, 94.5, 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99, 99.5 and about 100 weight percent.

In another suitable embodiment, the at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or the at least about 20 weight The percentage of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or the mixture of at least about 20 weight percent is selected from any of the foregoing two percentage values. The defined range (endpoints included).

In one embodiment, the working fluid used to extract heat may be comprised of HFO-1336mzz-Z. In another embodiment, the working fluid used to extract heat may be comprised of HFO-1336mzz-E. In another embodiment, the working fluid used to extract heat may be comprised of a mixture of HFO-1336mzz-Z and HFO-1336mzz-E.

It should be noted that at high operating temperatures, cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) in the working fluid may undergo isomerization. It becomes its trans isomer, namely trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E). It has surprisingly been found that such isomerization can be extremely small even at high temperatures of, for example, 250 °C.

The working fluid may also comprise less than about 80 weight percent of one or more other components selected from the group consisting of: cis-HFO-1234ze, anti-HFO-1234ze, HFO-1234yf, HFO-1234ye-E or Z, HFO-1225ye(Z), HFO-1225ye(E), HFO-1243zf(3,3,3-trifluoropropene), HFO1225yc, HFO-1233zd-E or Z, HFC-1233xf, CF ₃ CH=CHCF ₃ ( E), (CF ₃ ) ₂ CFCH=CHF(E & Z), (CF ₃ ) ₂ CFCH=CF ₂ , CF ₃ CHFC=CHF(E & Z), (C ₂ F ₅ )(CF ₃ )C= CH ₂ , HFC-245fa, HFC-245eb, HFC-245ca, HFC-245cb, HFC-227ea, HFC-236cb, HFC-236ea, HFC-236fa, HFC-365mfc, HFC-43-10mee, CHF ₂ -O- -CHF ₂ , CHF ₂ -O-CH ₂ F, CH ₂ FO-CH ₂ F, CH ₂ FO-CH ₃ , ring-CF ₂ -CH ₂ -CF ₂ -O, ring-CF ₂ -CF ₂ -CH ₂ -O, CHF ₂ -O--CF ₂ -CHF ₂ , CF ₃ -CF ₂ -O-CH ₂ F, CHF ₂ -O-CHF-CF ₃ , CHF ₂ -O-CF ₂ -CHF ₂ ,CH ₂ FO-CF ₂ -CHF ₂ , CF ₃ -O-CF ₂ -CH ₃ , CHF ₂ -CHF-O-CHF ₂ , CF ₃ -O-CHF-CH ₂ F, CF ₃ -CHF-O-CH ₂ F, CF ₃ -O-CH ₂ -CHF ₂ , CHF ₂ -O-CH ₂ -CF ₃ , CH ₂ F-CF ₂ -O-CH ₂ F, CHF ₂ -O-CF ₂ -CH ₃ , CHF ₂ -CF ₂ -O-CH ₃ , CH ₂ FO-CHF--CH ₂ F, CHF ₂ -CHF-O- CH ₂ F, CF ₃ -O-CHF-CH ₃ , CF ₃ -CHF-O-CH ₃ , CHF ₂ -O-CH ₂ -CHF ₂ , CF ₃ -O-CH ₂ -CH ₂ F, CF ₃ - CH ₂ -O-CH ₂ F, CF ₂ H-CF ₂ -CF ₂ -O-CH ₃ , propane, cyclopropane, butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane Alkane, n-hexane, isohexane, heptane, trans-1,2-dichloroethylene and mixtures thereof with cis-HFO-1234ze and HFC-245fa.

In an embodiment of the foregoing process, the working fluid comprises 80% by weight or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 70 weight percent or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 60 weight percent or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 50 weight percent or less of at least one of the foregoing compounds.

Note that although the working fluid in the foregoing process description is referred to as a "first" working fluid and a "second" working fluid, it should be understood that the difference between the two working fluids is only that the first working fluid is entering the ORC system. And the second working fluid is a fluid that has undergone at least one step of the foregoing process.

In an embodiment of the foregoing process, the temperature at which the first working fluid is heated in the step (b) is in the range of from about 50 ° C to about 400 ° C, preferably in the range of from about 150 ° C to about 300 ° C. It is preferably in the range of about 175 ° C to 275 ° C, and more preferably in the range of about 200 ° C to 250 ° C.

In a suitable embodiment, the operating temperature at the inlet of the expander can be any of the following temperatures or within a range defined by any two of the following values (end points are included): about 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162 and about 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177 , 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202 , 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227 , 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252 ,253,254,255,256,257,258,259,260,261,262,263,264,265,266,267,268,2 69, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 323, 323, 324, 325, 326, 327, 328, 329, 330, 331, 323, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400 °C.

In an embodiment of the foregoing process, the working fluid in step (a) is pressurized to a range of from about 3 MPa to about 10 MPa. In a suitable embodiment, the operating pressure can be any of the following pressures or within a range defined by any two of the following values (end points are included): about 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 and 10.0 MPa.

In an embodiment of the foregoing process, the working fluid has a GWP of less than 35. In a suitable embodiment, the GWP can be any of the following values or within the range defined by any two of the following values (endpoints are included): 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5 and about 35.

In the first step of the aforementioned transcritical organic Rankine cycle (ORC) system, comprising at least about 20 weight percent of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz) -Z) or at least about 20 weight percent of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of the liquid phase of the mixture thereof The workflow system is compressed above its critical pressure. The critical pressure of HFO-1336mzz-Z is 2.903 MPa, while the critical pressure of HFO-1336mzz-E is 3.149 MPa. In a second step, the fluid is heated to a higher temperature by a heat exchanger prior to entering the expander, wherein the heat exchanger is in thermal communication with the heat source. In other words, the heat exchanger receives thermal energy from the heat source by any known heat transfer means. The ORC system working fluid circulates in the heat recovery heat exchanger and obtains heat.

In the next step, at least a portion of the heated first working fluid is removed from the heat exchanger. The working fluid is routed to the expander, where at least a portion of the energy content of the working fluid is converted to mechanical energy, typically shaft energy, during the expansion process of the expander. The shaft power can be used for any mechanical work by using a conventionally configured belt, pulley, gear, transmission or the like depending on the desired speed and the required torque. In an embodiment, the shaft may also be coupled to an electrodynamic generating device such as an induction generator. The electricity generated can be used locally or transmitted to the transmission grid. The pressure of the working fluid is lowered below the critical pressure of the working fluid, thereby causing the working fluid to become the first working fluid of the vapor phase.

In the next step, the working fluid, now vapor phase, is passed from the expander to the condenser where the working fluid of the vapor phase is condensed into a working fluid in the liquid phase. The foregoing steps form a loop system and can be repeated many times.

Example 1 - Transcritical ORC; Complete Dry Expansion

Figure 5 shows an embodiment of the invention in which a transcritical ORC is used. Fig. 5 is a pressure-enthalpy diagram of the cycle of the present embodiment. The substantial vertical line in the figure is an isentropic line. The line that is vertical in the left half of the curve but begins to show deviation and bends in the right half of the figure is an isotherm. The dotted line to the left of the dome shape is the saturated liquid line. The dotted line to the right of the dome shape is the saturated vapor line. In a first step, the working fluid is compressed (pressurized) above the critical pressure of the working fluid, which is typically substantially isentropic. It is then heated to a temperature above its critical temperature under substantially fixed pressure (isostatic) conditions. In the next step, the working fluid is typically expanded in a substantially isentropic manner. The fluid temperature is lowered below its critical temperature during the expansion step. The fluid at the end of the expansion step is in a superheated vapor state. In the next step, the working fluid is cooled and condensed, and the heat is discharged and the temperature is lowered. The working fluid passes through two phase change boundaries, the saturated vapor curve shown on the right, and then the saturated liquid curve on the left. At the end of this step the working fluid is in a slightly subcooled liquid state.

Example 2 - Transcritical ORC; partial condensation at expansion / dry vapor at the exit of the expander

Figure 6 shows an embodiment of the invention in which a transcritical ORC is used. Figure 6 is a pressure-enthalpy diagram of the cycle of the present embodiment. The substantial vertical line in the figure is an isentropic line. The line that is vertical in the left half of the curve but begins to show deviation and bends in the right half of the figure is an isotherm. The dotted line to the left of the dome shape is the saturated liquid line. The dotted line to the right of the dome shape is the saturated vapor line. In the first step, the working fluid is compressed (pressurized) higher than the work The critical pressure of a fluid, which is usually substantially isentropic. It is then heated to a temperature above its critical temperature under substantially fixed pressure conditions.

The extent to which the working fluid temperature is above its critical temperature is such that, in the next step, the working fluid is generally expanded in a substantially isentropic manner and its temperature is lowered, the isentropic expansion is substantially followed by expansion to cause partial condensation or fogging of the working fluid. Saturated vapor curve. At the end of this expansion step, however, the workflow system is in a superheated vapor state, i.e., it is on the right side of the saturated vapor curve.

In the next step, the working fluid is cooled and condensed and the heat is removed and the temperature is lowered. The working fluid passes through two phase change boundaries, the saturated vapor curve shown on the right, and then the saturated liquid curve on the left. At the end of this step the workflow system is in a slightly subcooled liquid state.

Example 3 - Transcritical ORC; Wet Expansion; T _{Expander_Inlet} >T _Critical

Figure 7 shows an embodiment of the invention in which a transcritical ORC is used. Figure 7 is a pressure-enthalpy diagram of the cycle of the present embodiment. The substantial vertical line in the figure is an isentropic line. The line that is vertical in the left half of the curve but begins to show deviation and bends in the right half of the figure is an isotherm. The dotted line to the left of the dome shape is the saturated liquid line. The dotted line to the right of the dome shape is the saturated vapor line.

In a first step, the working fluid is compressed (pressurized) above the critical pressure of the working fluid, which is typically substantially isentropic. It is then heated to a temperature that is only slightly above its critical temperature under substantially fixed pressure conditions.

The extent to which the working fluid temperature is above its critical temperature is reduced only when the working fluid is normally expanded in a substantially isentropic manner in the next step. Temperature, and isentropic expansion is wet expansion. Specifically, the working fluid is a vapor-liquid mixture at the end of this expansion step.

In the next step, the working fluid is cooled, the vapor portion of the working fluid is partially condensed and the heat is removed and the temperature is lowered. The working fluid in the vapor-liquid mixture state passes through the phase change boundary of the saturated liquid curve. At the end of this step the workflow system is in a slightly subcooled liquid state.

Example 4 - Transcritical ORC; Wet Expansion; T _{Expander_Inlet} <T _Critical

Figure 8 shows an embodiment of the invention in which a transcritical ORC is used. Figure 8 is a pressure-enthalpy diagram of the cycle of the present embodiment. The substantial vertical line in the figure is an isentropic line. The line that is vertical in the left half of the curve but begins to show deviation and bends in the right half of the figure is an isotherm. The dotted line to the left of the dome shape is the saturated liquid line. The dotted line to the right of the dome shape is the saturated vapor line.

In a first step, the working fluid is compressed (pressurized) above the critical pressure of the working fluid, which is typically substantially isentropic. It is then heated to a temperature below its critical temperature under substantially fixed pressure conditions.

In the next step, the working fluid is typically expanded in a substantially isentropic manner to a low pressure and temperature state (wet expansion) that forms a vapor-liquid mixture.

In the next step, the working fluid is cooled, the vapor portion of the working fluid is condensed and heat is removed. At the end of this step the workflow system is in a slightly subcooled liquid state.

Although the foregoing examples show substantial isentropic, isothermal or isothermal expansion and pressurization, and isostatic heating or cooling, others do not maintain, for example, isentropic, etc. Other cycles of helium, isothermal or isostatic conditions but completing the cycle are also within the scope of the invention.

One embodiment of the present invention relates to a Variable Phase Cycle or a Trilateral Cycle (Phil Welch and Patrick Boyle: "New Turbines to Enable Efficient Geothermal Power Plants" GRC Transactions , Vol. 33, 2009). . The liquid working fluid is pressurized and then heated in a heat exchanger without evaporation. The heated, pressurized liquid exiting the heat exchanger is expanded directly in the two-phase expander. Condensing the low pressure fluid and closing the cycle.

In one embodiment, the present invention is directed to a working fluid composition for recovering heat from a heat source in an ORC system, wherein the working fluid composition is maintained at a temperature in the range of from about 175 ° C to about 300 ° C, preferably from about 200 ° C. a range of 250 ° C, and wherein the composition comprises at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or at least about 20 weight Percent of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of its mixture.

ORC system

In yet another embodiment, the present invention is directed to an ORC system using a novel working fluid, wherein the working fluid comprises at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2 - butene (HFO-1336mzz-Z) or at least about 20 weight percent of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight Percent of its mixture. In another embodiment of the system, the working fluid comprises at least 30 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment of the system, the working fluid comprises at least 40% by weight of HFO-1336mzz-Z, HFO-1336mzz-E or a mixture thereof. In another embodiment of the system, the working fluid comprises at least 50 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof.

In an embodiment of the foregoing system, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 10 weight percent HFO-1336mzz-E and 90 or more weight percent HFO-1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 15 weight percent HFO-1336mzz-E and 85 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 20 weight percent HFO-1336mzz-E and 80 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 25 weight percent HFO-1336mzz-E and 75 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising from about 25 weight percent to about 75 weight percent HFO-1336mzz-E and about 75 weight percent to About 25 weight percent of HFO-1336mzz-Z.

In one embodiment, the working fluid in the ORC system can be comprised of HFO-1336mzz-Z. In another embodiment, the working fluid in the ORC system can be comprised of HFO-1336mzz-E. In another reality In the example, the working fluid in the ORC system can be composed of a mixture of HFO-1336mzz-Z and HFO-1336mzz-E.

In another embodiment, the invention comprises an organic Rankine cycle system for extracting heat at an operating pressure in the range of from about 3 MPa to about 10 MPa, wherein the system contains a working fluid, and wherein about 50 weight percent of the work The fluid comprises HFO-1336mzz-Z, HFO-1336mzz-E or a mixture thereof.

The novel working fluid of the present invention can be used in an ORC system to extract thermal energy from a heat source and convert it into mechanical energy, such as low pressure steam, low order energy such as industrial waste heat, solar energy, geothermal hot springs, low pressure geothermal steam ( Primary or secondary configuration) or a decentralized power plant utilizing a fuel cell or a prime mover such as a turbine, micro-turbine or internal combustion engine. Low pressure steam can also be obtained in processes well known as binary Rankine cycles. A large amount of low pressure steam can be found in many places, such as fossil fuel-driven power generation plants. The working fluid of the present invention can be modified to match the power plant coolant characteristics (its temperature) to achieve maximum efficiency of the binary cycle.

Other heat sources include waste heat recovered from mobile internal combustion engines (such as diesel engines for trucks or trains or ships), exhaust gases from aircraft engines, waste heat from gases emitted from stationary internal combustion engines (such as stationary diesel engine generators), and fuel from fuel. Waste heat from batteries, heat from complex heating, cooling and power or district heating and cooling plants, waste heat from biofuel engines, methane from a variety of sources including biogas, landfill gas and coal bed methane Natural gas or methane gas or methane-fired boilers or methane fuel cells (eg in decentralized power plants), heat from paper mills burning bark and lignin, heat from incinerators, from traditional steam power plants Use at least about 20% by weight of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or at least about 20% by weight of anti-1,1,1,4,4 , 4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of the composition of the mixture as a working fluid to drive the heat of the "bottom" Rankine cycle of low pressure steam for use About 20% by weight of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or at least about 20% by weight of anti-1,1,1,4, 4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of the composition of the mixture thereof as a Rankine cycle in which the working fluid circulates on the ground (eg, a binary cycle geothermal power plant) Geothermal, used as a mixture of HFO-1336mzz-Z or HFO-1336mzz-E or HFO-1336mzz-Z and HFO-1336mzz-E as a Rankine cycle working fluid and as a dedicated or large temperature-induced fluid density change drive The geothermal heat of the geothermal carrier circulating in deep underground wells (known as the "thermo siphon effect" (see, for example, Davis, AP and EE Michaelides: "Geothermal power production from abandoned oil wells", Energy, 34 (2009) 866-872; Matthews, HB U.S. Patent No. 4,142,108-Feb. 27, 1979)), solar heat from solar panel arrays containing parabolic solar panel arrays, solar heat from photovoltaic solar power plants, self-photovoltaic (PV) solar system removal to cool PV systems The heat that maintains the efficiency of high PV systems. In other embodiments, the present invention also uses other types of ORC systems, such as a small scale (e.g., 1-500 kw, preferably 5-250 kw) Rankine cycle system using a micro-turbine or a small-sized positive displacement expander (e.g. Tahir, Yamada and Hoshino: "Efficiency of compact organic Rankine cycle system with Rotary-vane-type expander for low-temperature waste heat recovery", Int'l. J. of Civil and Environ. Eng 2:12010), composite multi-stage and multi-level Rankine cycle and with reheater to leave The vapor of the expander recovers the heat of the Rankine cycle system.

Other heat sources include at least one operation selected from at least one of the group consisting of: refining industry, petrochemical plant, oil and gas pipeline industry, chemical industry, commercial building, hotel, shopping mall, supermarket, baking industry , food processing industry, restaurants, paint curing ovens, furniture manufacturing, plastic molding, cement kiln, wood kiln, calcining operations, steel industry, glass industry, wafer industry, smelting industry, air conditioning industry, refrigeration industry and Central heating.

Method of replacing HFC-245fa in ORC system

Current ORC systems utilizing HFC-245fa may require a new working fluid with a lower global warming potential (GWP). The GWP of HFC-245fa is 1030. The GWP of the working fluid of the present invention is quite low. HFO-1336mzz-Z has a GWP of 9.4, while HFO-1336mzz-E has a GWP of about 32. Thus for ORC systems using HFO-1336mzz-Z, HFO-1336mzz-E or mixtures thereof, many working fluids can be formulated to provide a working fluid that is more environmentally sustainable.

In one embodiment, a method of replacing HFC-245fa in a power cycle system is provided, comprising removing the HFC-245fa from the power cycle system and comprising at least about 20 weight percent HFO-1336mzz-Z, HFO An alternative working fluid of -1336mzz-E or a mixture thereof fills the system. In another embodiment, the replacement working fluid comprises at least 30 weight percent HFO-1336mzz-Z, HFO-1336mzz-E or a mixture thereof. In another embodiment, the replacement working fluid comprises at least 40 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the replacement working fluid comprises at least 50 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof.

In an embodiment of the foregoing process, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 10 weight percent HFO-1336mzz-E and 90 or more weight percent HFO-1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 15 weight percent HFO-1336mzz-E and 85 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 20 weight percent HFO-1336mzz-E and 80 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 25 weight percent HFO-1336mzz-E and 75 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising from about 25 weight percent to about 75 weight percent HFO-1336mzz-E and about 75 weight percent to About 25 weight percent of HFO-1336mzz-Z.

The aforementioned working fluid comprises at least about 20 weight percent of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or at least about 20 Percent by weight of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or at least about 20 weight percent of its mixture. In another embodiment, the working fluid comprises at least 30 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the working fluid comprises at least 40 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In another embodiment, the working fluid comprises at least 50 weight percent HFO-1336mzz-Z, HFO-1336mzz-E, or a mixture thereof. In a suitable embodiment, the at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or the at least about 20 weight percent The trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or the mixture of at least about 20 weight percent is selected from the following percentages of the working fluid: About 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44 45, 46, 47, 48, 49, 50, 50.5, 51, 52, 52.5, 53, 53.5, 54, 54.5, 55, 55.5, 56, 56.5, 57, 57.5, 58, 58.5, 59, 59.5, 60 , 60.5, 61, 61.5, 62, 62.5, 63, 63.5, 64, 64.5, 65, 65.5, 66, 66.5, 67, 67.5, 68, 68.5, 69, 69.5, 70, 70.5, 71, 71.5, 72, 72.5 , 73, 73.5, 74, 74.5, 75, 55.5, 76, 76.5, 77, 77.5, 78, 78.5, 79, 79.5, 80, 80.5, 81, 81.5, 82, 82.5, 83, 83.5, 84, 84.5, 85 , 85.5, 86, 86.5, 87, 87.5, 88, 88.5, 89, 89.5, 90, 90.5, 91, 91.5, 92, 92.5, 93, 93.5, 94, 94.5, 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99, 99.5 and about 100%.

In another suitable embodiment, the at least about 20 weight percent cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z) or the at least about 20 weight The percentage of trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-E) or the mixture of at least about 20 weight percent is selected from any of the foregoing two percentage values. The defined range (endpoints included).

In an embodiment of the foregoing process, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 10 weight percent HFO-1336mzz-E and 90 or more weight percent HFO-1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 15 weight percent HFO-1336mzz-E and 85 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 20 weight percent HFO-1336mzz-E and 80 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising at least about 25 weight percent HFO-1336mzz-E and 75 or more weight percent HFO- 1336mzz-Z. In another embodiment, wherein the working fluid comprises a mixture of HFO-1336mzz-Z and HFO-1336mzz-E, the working fluid comprising from about 25 weight percent to about 75 weight percent HFO-1336mzz-E and about 75 weight percent to about 25 weight percent HFO-1336mzz-Z.

The working fluid may also comprise less than about 80 weight percent of one or more other components selected from the group consisting of: cis-HFO-1234ze, anti-HFO-1234ze, HFO-1234yf, HFO-1234ye-E or Z , HFO 1225ye (Z), HFO-1225ye (E), HFO-1225yc, HFO-1243zf (3,3,3-trifluoropropene), HFO-1233zd-E or Z, HFO-1233xf, CF ₃ CH=CHCF ₃ (E), (CF ₃ ) ₂ CFCH=CHF(E & Z), (CF ₃ ) ₂ CFCH=CF ₂ , CF ₃ CHFC=CHF(E & Z), (C ₂ F ₅ )(CF ₃ ) C=CH ₂ , HFC-245fa, HFC-245eb, HFC-245ca, HFC-245cb, HFC-227ea, HFC-236cb, HFC-236ea, HFC-236fa, HFC-365mfc, HFC-43-10mee, CHF ₂ - O--CHF ₂ , CHF ₂ -O-CH ₂ F, CH ₂ FO-CH ₂ F, CH ₂ FO-CH ₃ , cyclo-CF ₂ -CH ₂ -CF ₂ -O, ring-CF ₂ -CF ₂ -CH ₂ -O, CHF ₂ -O--CF ₂ -CHF ₂ , CF ₃ -CF ₂ -O-CH ₂ F, CHF ₂ -O-CHF-CF ₃ , CHF ₂ -O-CF ₂ -CHF ₂ , CH ₂ FO-CF ₂ -CHF ₂ , CF ₃ -O-CF ₂ -CH ₃ , CHF ₂ -CHF-O-CHF ₂ , CF ₃ -O-CHF-CH ₂ F, CF ₃ -CHF-O- CH ₂ F, CF ₃ -O-CH ₂ -CHF ₂ , CHF ₂ -O-CH ₂ -CF ₃ , CH ₂ F-CF ₂ -O-CH ₂ F, CHF ₂ -O-CF ₂ -CH ₃ , CHF ₂ -CF ₂ -O-CH ₃ , CH ₂ FO-CHF--CH ₂ F, CHF ₂ -CHF-O-CH ₂ F, CF ₃ -O-CHF-CH ₃ , CF ₃ -CHF-O-CH ₃ , CHF ₂ -O-CH ₂ -CHF ₂ , CF ₃ -O-CH ₂ -CH ₂ F, CF ₃ -CH ₂ -O-CH ₂ F, CF ₂ H-CF ₂ -CF ₂ -O-CH ₃ , propane, cyclopropane, butane, isobutane, n-pentane, isopentane, new Pentane, cyclopentane, n-hexane, isohexane, heptane, trans-1,2-dichloroethylene and mixtures thereof with cis-HFO-1234ze and HFC-245fa.

In an embodiment, the working fluid comprises 80% by weight or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 70 weight percent or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 60 weight percent or less of at least one of the foregoing compounds. In another embodiment, the working fluid comprises 50 weight percent or less of at least one of the foregoing compounds.

In an embodiment, the working fluid used to extract heat may be comprised of HFO-1336mzz-Z. In another embodiment, the working fluid used to extract heat may be comprised of HFO-1336mzz-E. In another embodiment, the working fluid used to extract heat may be comprised of a mixture of HFO-1336mzz-Z and HFO-1336mzz-E.

Instance

The concepts described herein are further illustrated by the following examples which do not limit the scope of the invention described in the claims.

Example A

Example A shows the heat generated by the diesel engine under subcritical conditions using the Rankine cycle of HFO-1336mzz-Z, where the evaporation temperature T _{evap is} lower than the critical temperature of HFO-1336mzz-Z (T _{cr_HFO-1336mzz-Z} =171.28 ° C).

The following example shows the use of heat extracted from a gas discharged from an internal combustion engine (for example, a diesel engine) using a Rankine cycle system using HFO-1336mzz-Z as a working fluid to generate mechanical power. The mechanical power generated by the Rankine cycle is in addition to the mechanical power generated by the engine from the combustion of the fuel, and it increases the total amount of mechanical power generated per unit of combustion fuel mass.

Compare the performance of the working fluid containing HFO-1336mzz-Z (CF ₃ CH=CHCF ₃ ) with the well-known working fluid HFC-245fa (CHF ₂ CH ₂ CF ₃ ).

Example A1: Low temperature operation (T _evaporator = 132.22 ° C)

Evaporator (boiler) temperature: T _evaporator = 270 ° F = 132.22 ° C

Condenser temperature: T _condenser = 130 ° F = 54.44 ° C

_Superheated steam entering the expander: △T _suph =36°F=20°C

_Subcooled liquid: △T _subc =14°F=7.78°C

Expander efficiency η _exp =0.85

Pump efficiency η _pump =0.85

Table A1 shows that HFO-1336mzz-Z can substantially match the energy efficiency of HFC-245fa while providing a lower GWP. Furthermore, HFO-1336mzz-Z produces operating pressures substantially lower than HFC-245fa. However, the HFO-1336mzz-Z produces a power volume (CAP) that is lower than HFC-245fa.

The thermal power efficiency of the Rankine cycle operating at HFO-1336mzz-Z was 11.41%, which substantially matched HFC-245fa under the same cycle operating conditions. The evaporator pressure (1.41 MPa) using HFO-1336mzz-Z is substantially lower than HFC-245fa (2.45 MPa). Compared to HFC-245fa, the use of HFO-1336mzz-Z requires a relatively high volumetric flow rate at the exit of the expander to produce the target mechanical power rate. Correspondingly, when the unit volume of HFO-1336mzz-Z is circulated in the cycle, a small amount of mechanical work (311.86 kJ/m3) is generated than HFC-245fa (543.63 kJ/m ³ ).

Example A2: High temperature operation (T _evaporator = 155 ° C)

HFO-1336mzz-Z has a higher critical temperature than HFC-245fa (see Table A2) and produces a lower vapor pressure. Therefore, HFO-1336mzz-Z can perform subcritical organic Rankine cycle operation at a temperature higher than HFC-245fa (see Table A3).

HFO-1336mzz-Z can be used as a working fluid for a subcritical organic Rankine cycle operating at a heat source that can bring the evaporator temperature to 155 ° C (ie, above the critical temperature of HFC-245fa). Table A3 shows that the evaporator temperature of 155 ° C is substantially improved by the efficiency and power generation volume compared to the evaporation temperature of 132.22 ° C (14.90% and 18.53% improvement, respectively).

Example A3: High temperature operation (T _evaporator = 161.60 ° C)

At a certain temperature, HFO-1336mzz-Z produces a lower vapor pressure than HFC-245fa. Therefore, at any particular maximum allowable evaporator operating pressure, HFO-1336mzz-Z allows the organic Rankine cycle to operate at higher evaporator temperatures than HFC-245fa. Table A4 compares the organic Rankine cycle operating at HFO-1336mzz-Z with an evaporator temperature of 161.6 °C and operating at HFC-245fa with an evaporator temperature of 132.22 °C. Organic Langken cycle. Both cycles were run at an evaporator operating pressure of 2.45 MPa. The cycle operating with HFO-1336mzz-Z achieved a higher energy efficiency (13.51%) than HFC-245fa (11.42%).

Instance B

Example B shows that the Rankine cycle using HFO-1336mzz-Z generates power from the heat emitted by the diesel engine under transcritical conditions.

Unexpectedly, HFO-1336-mzz-Z maintains chemical stability at temperatures substantially above its critical temperature (171.28 °C). Therefore, HFO-1336-mzz-Z can achieve the Rankine cycle using HFO1336-mzz-Z as the working fluid in the supercritical state and obtaining a heat source with a temperature higher than 171.28 °C. The higher the temperature of the heat source, the higher the cycle energy efficiency and the volume generated by the power (compared to the use of a low temperature heat source).

When using a supercritical fluid heater instead of a conventional subcritical Rankine cycle evaporator (or boiler), the heater pressure and heater outlet temperature (or corresponding expander inlet temperature) must be indicated. Figure 3 shows the energy efficiency of a cross-critical Rankine cycle operating with HFO-1336mzz-Z as the working fluid versus the pressure of the supercritical fluid heater and the temperature of the working fluid at the inlet of the expander. For example, operating a supercritical fluid heater at a pressure of 5 MPa and a heater outlet temperature of 225 ° C (or expander inlet temperature) can achieve a Rankine cycle energy efficiency of 15.5%. The higher the expander inlet temperature, the higher the maximum heater pressure can be achieved. The higher operating pressures in supercritical fluid heaters require the more robust equipment to be used.

Usually the temperature of the heat source is reduced during the heat exchange process. In the subcritical Rankine cycle operation example, the temperature of the working fluid is fixed during the heat extraction evaporation process. Compared to the subcritical operation example, the use of supercritical fluid to extract thermal energy has a good match between the temperature of the heat source and the supercritical working fluid. Thus, the effect of the heat exchange procedure of the transcritical cycle can be higher than that of the subcritical cycle (see Chen et al., Energy, 36, (2011) 549-555 and incorporated herein by reference).

Example B1: T _{expander _ inlet} = 200 or 250 ° C transcritical organic Rankine cycle

Table B1 shows the Rankine cycle of heating the HFO-1336mzz-Z to 200 °C before 3 MPa and then expanding the heated HFO-1336mzz-Z to a condenser of Tcond=54.44 °C (0.21 MPa), which can reach 14.2 The thermal efficiency of % and the volume generated by the power of 412.03 kJ/m ³ . When the working fluid (HFO-1336mzz-Z) is heated to 250 ° C under a pressure of 6 MPa, it can even reach higher efficiency and volume generated by power. HFO-1336mzz-Z still maintains sufficient stability at 250 °C. In Example A, the transcritical cycle achieves higher efficiency and volume relative to the subcritical cycle. Table B2 compares HFO-1336mzz-Z and HFC-245fa with the same fluid heater pressure, heater outlet temperature, condenser temperature, liquid subcooling, expander efficiency, and liquid compressor (ie pump) efficiency. The effectiveness of the cross-critical Rankine cycle of the working fluid.

Example C1: Subcritical ORC using HFO-1336mzz-Z at an evaporator pressure of 2.18 MPa

Table C1 shows that HFO-1336mzz-Z can combine the organic Rankine cycle with commonly available low cost HVAC-type equipment that operates at moderate evaporator pressures (not exceeding about 2.18 MPa) while providing attractive safety, Health and environmental characteristics as well as attractive energy efficiency. The practical application of real-life expansion of ORC using low-cost equipment (see Joost J. Brasz, Bruce P. Biederman and Gwen Holdmann: "Power Production from a Moderate-Temperature Geothermal Resource", GRC Annual Meeting, September 25-28th, 2005; Reno , NV, USA). Table C1 shows that the energy efficiency of 15.51% for HFO-1336mzz-Z is 15.06% higher than that for HFC-245fa.

Example C2: Transcritical ORC operating with HFO-1336mzz-Z as the working fluid

For both HFO-1336mzz-Z and HFC-245fa, the Rankine cycle energy efficiency of the expander inlet temperature of 250 °C increases monotonically as the heater pressure increases from above the critical pressure to 9 MPa. The heater pressure (9 MPa) selected in Table C2 is higher than the maximum working pressure of most commonly used HVAC equipment.

Table C2 shows that HFO-1336mzz-Z enables the transcritical Rankine cycle system to convert heat available at a relatively high temperature (250 ° C) to an energy efficiency of 2.7% higher than HFC-245fa (under the same operating conditions). Power while providing more attractive safety and environmental features.

Tables C1 and C2 show that the HFO-1336mzz-Z can be used to convert the heat available at a relatively high temperature (250 °C) into a dynamic transcritical Rankine cycle system that achieves a subcritical ORC operation with HFO-1336mzz-Z. To have high energy efficiency.

Example C3: Supercritical Fluid Heater Pressure for Maximum Energy Efficiency for a Rankine Cycle Operating at HFO-1336mz-Z for a Selected Expander Inlet Temperature

Figure 4 shows a plot of energy efficiency versus heater pressure at different expander inlet temperatures. It has unexpectedly been found that energy efficiency increases with higher heater pressure at the expander inlet temperature. The efficiency of the extruder temperature at 250 ° C at 10 MPa was found to be greater than 18%.

Example C4: Chemical Stability of HFO-1336mzz-Z

The chemical stability of HFO-1336mzz-Z in the presence of metals was tested according to the sealed tube test method of ANSI/ASHRAE Standard 97-2007. The HFO-1336mzz-Z material used for the sealed tube test was 99.9864 + weight percent (136 ppmw impurity) and was substantially free of water or air.

The sealed glass tubes each containing three metal test pieces made of steel, copper and aluminum and infiltrated in HFO-1336mzz-Z were aged for 14 days in a heating oven of various temperatures up to 250 °C. After hot curing, the sealed glass tube was visually inspected to show a clear liquid with no discoloration or other visible fluid deterioration. Furthermore, the appearance of the metal test piece did not show any change in corrosion or other deterioration.

Table C3 shows the fluoride ion concentration measured in the aged liquid sample. The fluoride ion concentration can be interpreted as an indicator of the degree of deterioration of HFO-1336mzz-Z. Table C3 shows that the degradation of HFO-1336mzz-Z is surprisingly small even at the highest test temperature (250 °C).

Table C4 shows the compositional changes quantified by GCMS for HFO-1336mzz-Z samples after two weeks of curing at various temperatures in the presence of steel, copper and aluminum. Even at the highest test temperature (250 ° C), ripening only results in a new unknown compound that is negligible.

The trans isomer of HFO-1336mzz, HFO-1336mzz-E, is expected to have about 5 kcal/mole of thermodynamic stability over the cis isomer HFO-1336mzz-Z. Unexpected, although useful In terms of the substantial thermodynamic driving force that makes HFO-1336mzz-Z a heterogeneous trans isomer, the measurement in Table C4 shows that even at the highest test temperature (250 ° C), HFO-1336mzz- Z is still present in large amounts in the Z (or cis) isomeric form. The thermodynamic properties of the working fluid (HFO-1336mzz-Z) and the effect on the cycle performance of a small portion of HFO-1336mzz-E (3,022.7 ppm or 0.30227 weight percent) formed after two weeks of ripening at 250 °C can be ignored.

Example D Subcritical ORC of HFO-1336mzz-E at an evaporator pressure of 2.18 MPa

Table D compares the performance of the subcritical Rankine cycle with HFO-1336mzz-E as the working fluid and the subcritical Ranken cycle with HFO-1336mzz-Z or HFC-245fa as the working fluid. The evaporator pressures for all cycles compared in Table D were 2.18 MPa. The cycle energy efficiency of HFO-1336mzz-E is lower than HFC-245fa 8.46%. The volume produced by the power of HFO-1336mzz-E is 8.6% higher than that of HFC-245fa.

The performance of HFC-245fa is summarized by the performance of HFO-1336mzz-Z and HFO-1336mzz-E. This represents a blend of HFO-1336mzz-Z and HFO-1336mzz-E that can be used to replace HFC-245fa in both Rankine cycle applications.

Example E Subcritical ORC of HFO-1336mzz-E at an evaporator temperature of 120 °C

Table E compares the Rankine cycle efficiency with HFO-1336mzz-E compared to HFO-1336mzz-Z and HFC-145fa at an evaporation temperature of 120 °C. The cycle energy efficiency with HFO-1336mzz-E is 3.8% lower than that of HFC-245fa. The volume produced by the power of HFO-1336mzz-E is 16.2% higher than that of HFC245fa.

The performance of HFC-245fa is summarized by the performance of HFO-1336mzz-Z and HFO-1336mzz-E. This represents a blend of HFO-1336mzz-Z and HFO-1336mzz-E that can be used to replace HFC-245fa in both Rankine cycle applications.

Example F Subcritical ORC with HFO-1336mzz-E/HFO-1336mzz-Z as working fluid

Table F summarizes the Rankine cycle efficiencies of the three different components of the HFO-1336mzz-E/HFO-1336mzz-Z blend. The composition of the HFO-1336mzz-E/HFO-1336mzz-Z blend can be varied to achieve different performance goals.

Example G Cross-critical ORC of HFO-1336mzz-E

Table G compares the 50/50 wt% blend of HFO-1336mzz-E, HFO-1336mzz-Z, HFO-1336mzz-E, and HFO-1336mzz-Z with the cross-critical ORC potency of HFC-245fa.

From the data, HFO-1336mzz-Z and its mixture with HFO-1336mzz-E provide efficiency close to HFC-245fa. In addition, the addition of HFO-1336mzz-E to HFO-1336mzz-Z allows the use of such a mixture to provide a volume that is close to the power generated by HFC-245fa while providing the industry with a more environmentally sustainable working fluid.

30‧‧‧Electrical power generating device

32‧‧‧Expansion machine

34‧‧‧Condenser

36‧‧‧Liquid buffer tank

38‧‧‧ pump

40‧‧‧heat exchanger

46‧‧‧heat source

30'‧‧‧Electrical power generating device

32'‧‧‧Expansion machine

34'‧‧‧Condenser

36'‧‧‧Liquid buffer tank

38'‧‧‧ pump

40'‧‧‧heat exchanger

42'‧‧‧ pump

46'‧‧‧heat source

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of a heat source for direct heat exchange and an organic Rankine cycle system in accordance with the present invention.

2 is a block diagram of a heat source and an organic Rankine cycle system in accordance with the present invention that uses a second loop configuration to provide heat from a heat source to a heat exchanger for conversion to mechanical energy.

Figure 3 shows the selected temperature of the working fluid at the inlet of the expander (T _cond = 54.44 ° C; T _subcooling = 7.78 ° C; expander efficiency = 0.85; and pump efficiency = 0.85), with HFO-1336mzz-Z as the working fluid A plot of the energy efficiency of a transcritical organic Rankine cycle operating with the pressure of a fluid heater.

Figure 4 shows the selected temperature of the working fluid at the inlet of the expander (T _cond = 40 ° C; T _subcooling = 0 ° C; expander efficiency = 0.85; and pump efficiency = 0.85), with HFO-1336mzz-Z as the working fluid A plot of the energy efficiency of a transcritical organic Rankine cycle operating with the pressure of a fluid heater.

Figure 5 shows a fully dry expanded transcritical ORC.

Figure 6 shows a transcritical ORC that partially condenses upon expansion but has dry vapor at the exit of the expander.

Figure 7 shows a transcritical ORC with a wet expansion and a temperature at the inlet of the expander that is above the critical temperature of the working fluid.

Figure 8 shows a transcritical ORC with a wet expansion but at a temperature at the inlet of the expander that is below the critical temperature of the working fluid.

Claims (3)

A process for recovering heat from a heat source and generating mechanical energy, comprising the steps of: (a) compressing a first working fluid of the liquid phase above a critical pressure of the first working fluid; (b) causing step (a) The first working fluid passes through a heat exchanger or a fluid heater and heats the first working fluid to a temperature higher or lower than a critical temperature of the first working fluid, wherein the heat exchanger or the fluid heater And communicating with the heat source that supplies heat; (c) removing at least a portion of the heated first working fluid from the heat exchanger or the fluid heater; (d) the at least a portion of the first working fluid being heated Passing to an expander; wherein at least a portion of the heat is converted to mechanical energy, and wherein the pressure of the at least a portion of the heated first working fluid is reduced to a lower pressure than the first working fluid, thereby At least a portion of the heated first working fluid becomes a first working fluid vapor or a first working fluid vapor and liquid mixture; (e) the first working fluid vapor or the first working fluid vapor Mixture delivered by the expander to a condenser, wherein the at least a portion of the first working fluid vapor in the vapor or liquid mixture of the first working fluid is fully condensed working fluid into the first liquid phase; Wherein the first working fluid is mainly composed of a refrigerant composed of a mixture of HFO-1336mzz-E or HFO-1336mzz-E and HFO-1336mzz-Z; wherein when the refrigerant is composed of the mixture, the first A working fluid comprises from 25 weight percent to 75 weight percent HFO-1336mzz-E. An organic Rankine cycle system for extracting heat at an operating pressure ranging from 3 MPa to 10 MPa, wherein the system contains a working fluid, and wherein the working fluid is mainly composed of a refrigerant consisting of HFO-1336mzz-E or HFO-1336mzz a mixture of -E and HFO-1336mzz-Z; wherein when the refrigerant consists of the mixture, the first working fluid comprises from 25 weight percent to 75 weight percent HFO-1336mzz-E. A method of replacing HFC-245fa in a power cycle system comprising removing the HFC-245fa from the power cycle system and filling the system with a working fluid consisting essentially of a refrigerant; wherein the refrigerant is HFO-1336mzz- E or a mixture of HFO-1336mzz-E and HFO-1336mzz-Z; wherein when the refrigerant consists of the mixture, the first working fluid comprises from 25 weight percent to 75 weight percent HFO-1336mzz-E.