Supersonic diffuser for turbomachine arranged to transfer thermal energy to process fluid

Abstract

A supersonic diffuser is provided for a turbine adapted to transfer thermal energy to a process fluid. The diffuser includes a vane region configured to define a channel having a flow area through which the process fluid flow passes at supersonic velocities. The vane region is configured to define a step change in the flow area of the channel at a given location, such as at a location where the process fluid flow exits the vane region. The diffuser further includes an impingement region coupled to the vane region to pass the process fluid stream exiting the vane region. The shockwave zone is configured to support a shockwave system that increases a static temperature of the process fluid downstream of the shockwave system. The mixing and subsonic diffusion zone is configured to decelerate the process fluid from the impingement zone to a reduced subsonic velocity before the process fluid is discharged through the outlet of the diffuser.

Description

Background Art

[0001] The disclosed embodiments relate generally to the field of turbomachines, and more particularly to turbomachines arranged to transfer thermal energy to a process fluid, such as for performing an endothermic process associated with the process fluid, and even more particularly to supersonic diffusers suitable for use in such turbomachines.

[0002] An endothermic process is a thermochemical process that involves heating a fluid to promote an endothermic reaction. Endothermic processes can be used in conjunction with various industrial operations to separate or "crack" molecules that may be components of the process fluid. Thermal cracking can involve breaking apart the chemical bonds of relatively complex molecular species to form simpler molecular species. Summary of the invention

[0003] In one aspect, a supersonic diffuser includes a blade section configured to define a passage having a flow area for passing a process fluid flow at a supersonic velocity. The blade section is configured to define a step change in the flow area of ​​the passage. An impingement zone is fluidly coupled to the blade section to pass a process fluid flow exiting the blade section. The impingement zone is configured to support a shock wave system that increases a static temperature of a process fluid downstream of the shock wave system. A mixing and subsonic diffusion zone is fluidly coupled to the impingement zone. A mixing and subsonic diffusion zone having a flow below a Mach number is configured to decelerate a process fluid from the impingement zone to a reduced subsonic velocity before the process fluid is discharged through an outlet of the supersonic diffuser.

[0004] The above content has generally summarized some technical features of the present disclosure so that those skilled in the art can better understand the detailed description below. Other features and advantages of the present disclosure that form the subject matter of the claims will be described below. Those skilled in the art will understand that they can easily use the disclosed schemes and specific embodiments as the basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of the present disclosure in its broadest form.

[0005] In addition, before describing the following detailed description, it should be understood that various definitions of certain words and phrases are provided throughout this patent document, and those skilled in the art will understand that these definitions apply in many, if not most, cases to existing and future uses of such defined words and phrases. Although some terms may include a variety of embodiments, the appended claims may expressly limit these terms to specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1is a schematic diagram of one non-limiting embodiment of a turbine arranged to transfer thermal energy to a process fluid.

[0007] Figure 2 is a partial cross-sectional view of a non-limiting embodiment of a disclosed supersonic diffuser that may form a turbine (e.g., Figure 1 A portion of the turbine shown.

[0008] Figure 3 is a partial cross-sectional view of another non-limiting embodiment of the disclosed supersonic diffuser.

[0009] Figure 4 yes Figure 3 Isometric view of the illustrated embodiment.

[0010] Figure 5 Various exemplary plots are shown for designing an impingement region in a disclosed supersonic diffuser, wherein the impingement region is configured to support a shock wave system that increases the static temperature of a process fluid.

[0011] Figures 6 to 8 are partial cross-sectional views of further non-limiting embodiments of the disclosed supersonic diffuser.

[0012] Fig. 9 is a partial cross-sectional view of yet another non-limiting embodiment of the disclosed supersonic diffuser that may form a portion of a turbomachine.

[0013] Fig.10 yes Fig. 9 Isometric view of the illustrated embodiment.

[0014] Fig.11 and Fig.12 are respective partial cross-sectional views of further embodiments of the disclosed supersonic diffuser, which embodiments may involve respective shock attenuation structures.

[0015] Fig.13 is a plot obtained from an example model of the disclosed supersonic diffuser. The plot shows the spatial distribution of static temperature in a process fluid that initially flows at supersonic speeds from the vane region of the diffuser to the impingement region and finally to the mixing and subsonic diffusion region of the diffuser. DETAILED DESCRIPTION

[0016] The disclosed supersonic diffuser embodiments effectively diffuse an internal supersonic flow of an elastomeric fluid, which can be used, for example, in a turbine arranged to transfer thermal energy to a process fluid to perform various industrial processes, which can, for example, involve thermochemical reactions for separating or "cracking" relatively complex molecular species (e.g., precursor molecular species) into simpler molecular species, which can, for example, have a relatively lower molecular weight than the precursor molecular species.

[0017] It should be appreciated that the disclosed supersonic diffuser embodiments not only convert the kinetic energy of the fluid into internal energy, but also provide an impingement region in which a desired increase in the static temperature of the fluid is achieved to initiate certain thermochemical reactions. The disclosed embodiments demonstrate a robust and compact topology that can appropriately handle a wide range of backpressures while substantially isolating upstream fluid flow conditions.

[0018] Before explaining the disclosed embodiments in detail, it should be understood that the disclosed embodiments are not limited in applicability to the details of construction and arrangement of components set forth in this specification or shown in the following drawings. The basic principles embodied in the disclosed embodiments may be implemented by further embodiments and may be practiced or performed in various ways. In addition, it should be understood that the words and terms used in the present invention are for descriptive purposes and should not be considered as limiting.

[0019] Various techniques related to the device and / or method will now be described with reference to the accompanying drawings, wherein the same reference numerals represent the same elements throughout. The accompanying drawings discussed below and the various embodiments for describing the principles of the present disclosure in this patent document are intended to be illustrative only and should not be interpreted as limiting the scope of the present disclosure in any way. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any suitably arranged device. It should be understood that the functions described as being performed by certain elements can be performed by multiple elements. Similarly, for example, an element can be constructed to perform the functions described as being performed by multiple elements. Multiple innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0020] It should be understood that the words or phrases used in the present invention should be interpreted broadly, unless explicitly limited in some examples. For example, the terms "include", "have" and "include" and their derivatives are meant to include but are not limited to. The singular forms "one", "an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. In addition, the term "and / or" used in the present invention refers to and covers any and all possible combinations of one or more items in the relevant listed items. The term "or" is inclusive, meaning and / or, unless the context clearly indicates otherwise. The phrases "associated with..." and "associated with it" and their derivatives can refer to including, being included in, interconnected with, including, being included in, connected to, or connected with, connected to, or connected with, can communicate with, collaborate with, interlace, juxtapose, approach, bound to, or bound with, have, have, etc. characteristics. In addition, although multiple embodiments or configurations can be described herein, any features, methods, steps, components, etc. described with respect to one embodiment are equally applicable to other embodiments without a specific description to the contrary.

[0021] In addition, although the terms "first", "second", "third", etc. can be used to refer to various elements, information, functions or actions in the present invention, these elements, information, functions or actions should not be limited by these terms. On the contrary, these ordinal adjectives are used to distinguish between different elements, information, functions or actions. For example, a first element, information, function or action can be referred to as a second element, information, function or action, and similarly, a second element, information, function or action can be referred to as a first element, information, function or action without departing from the scope of this disclosure.

[0022] Additionally, the term "adjacent" may refer to an element being relatively close to but not touching another element, or that the element is in contact with another part, unless the context clearly indicates otherwise. Additionally, the phrase "based on" is intended to mean "based at least in part on," unless otherwise clearly indicated. The terms "about" or "substantially" or similar terms are intended to encompass variations in values ​​within standard industry manufacturing tolerances for the dimensions described. If no industry standard is available, a variation of 20% will fall within the meaning of these terms unless otherwise indicated.

[0023] Figure 1 1 is a schematic diagram of a non-limiting embodiment of a turbine 100 configured to transfer thermal energy to a process fluid. Figure 1 As shown, multiple rows of rotatable blades 102 are coupled to a rotor shaft 104, which is in turn coupled to and driven by a shaft rotation power source or drive 106, such as an electric motor, a steam or gas turbine, or another turbine.

[0024] The rows of rotatable blades 102 transfer kinetic energy to the process fluid through a well-known momentum transfer process. Figure 1 In FIG. 1 , three rows of rotatable blades 102 are used to add kinetic energy to the process fluid. It should be understood that Figure 1 The number of rows of rotatable blades shown in should be interpreted as exemplary and not limiting, as the number may be adjusted based on the needs of any given application. The process fluid is then fluidly coupled to be processed by the supersonic diffuser 110 to decelerate the flow and convert kinetic energy in the process fluid into thermal energy, as described in more detail below.

[0025] Figure 2 is a partial cross-sectional view of a non-limiting embodiment of a supersonic diffuser 110 that is fluidly coupled to receive the supersonic diffuser 110 from the rotatable blades 102 ( Figure 1 ) is a process fluid flow leaving the most downstream row. The supersonic diffuser 110 includes a blade area 202, an impact area 204 and a mixing and subsonic diffusion area 206. The blade area 202 is configured to define a channel 203, which has a flow area for allowing the process fluid flow to pass at a supersonic speed. In this embodiment, the blade area 202 is configured to define a step-change in the flow area of ​​the channel at the position where the process fluid flow leaves the blade area. It should be understood that the blade area 202 is formed by a series of circumferentially arranged independent flow channels 203 leading to the impact area 204. That is, the impact area 204 is located downstream of the blade area 202. In order to avoid unnecessary visual confusion, only one such channel 203 is pointed to in the figure, because for each channel 203, the structural relationship and / or operational relationship will be the same.

[0026] Regardless of the specific implementation, the step change provides a sudden increase in flow area at a given location and results in the formation of a shock wave system that enters the impact zone 204, which in turn increases the static temperature of the process fluid, as explained in more detail below. That is, the step change in flow area per channel constitutes a specific discontinuous change in flow area at the interface between the blade area 203 and the impact zone 204 to induce the shock wave system. Typically, the transition between the blade area 203 and the impact zone 204 is defined by a step change in flow area, and then the impact zone 204 may or may not continue with a defined channel.

[0027] In an exemplary embodiment, Figure 2As shown, the blade area 202 includes a pair of spaced blades 210 disposed between the outer wall 212 and the inner wall 214 of the supersonic diffuser. In this embodiment, the pair of blades 210 are configured to make the flow direction of the process fluid parallel or approximately parallel along the axial direction of the supersonic diffuser 110 (schematically represented by the centerline 216). Each of the pair of blades 210 has a blunt trailing edge 218 (e.g., a truncated trailing edge) that defines a step change in the flow area of ​​the passage 203 along the circumferential direction. Once again, in order to avoid unnecessary visual confusion, only one pair of such pairs of spaced blades 210 is indicated in the figure, because the structural relationship and / or operational relationship of each pair of spaced blades 210 will be the same. In one embodiment, the position of the step change can be designed at the intersection of the blade area 202 and the impact zone 204.

[0028] It should be understood that in these embodiments ( Figure 2 ; Figure 3 ) is formed by a plurality of circumferentially positioned blade pairs 210 that collectively span 360 degrees of an annular space defined by an outer wall 212 and an inner wall 214, wherein each blade pair 210 defines a respective channel 203 for a respective stream or jet of a process fluid. That is, the plurality of circumferentially positioned blade pairs 210 collectively define a series of circumferentially arranged independent flow channels 203 leading to an impact zone 204.

[0029] In another embodiment, if Figure 3 and Figure 4 As shown, each blade pair 210 may include an axial extension characterized by a tapered section 220 (schematically represented by double-headed arrow 218) that allows a small amount of area expansion in the passage 203 before the process fluid leaves the blade area. This embodiment allows for greater tolerance to back pressure variations that may be encountered in a given application, depending on the needs of the given application. In this example, the total increase in flow area can be up to about 200%.

[0030] In another embodiment, if Fig. 9 and Fig.10 As shown, the blade area 202 includes a pair of low-camber blades 710. As an example, each corresponding blade in the pair of low-camber blades 710 can have a camber angle of about 20 degrees or less. The pair of low-camber blades 710 are placed between the outer wall 212 and the inner wall 214 of the supersonic diffuser. The pair of low-camber blades 710 are arranged to guide the process fluid flow to meet the step change of the flow area of ​​the channel 203. In this embodiment, at least one of the outer wall 212 and the inner wall 214 has a step change in radius (marked as Δr), which radially defines the step change of the flow area of ​​the channel 203.

[0031] In this embodiment, as described above, the blade area 202 is formed by a plurality of circumferentially positioned low-camber blade pairs 710 that collectively span 360 degrees of the annular space defined by the outer wall 212 and the inner wall 214, wherein each low-camber blade pair 710 defines a respective channel for a respective stream or jet of a process fluid. That is, the plurality of circumferentially positioned low-camber blade pairs 710 collectively define a series of circumferentially arranged independent flow channels 203 leading to the impact zone 204. For simplicity of description and explanation, the structural relationship and / or operational relationship of the plurality of circumferentially positioned low-camber blades 710 will be described with respect to only one of such low-camber blade pairs 710, as such structural relationship and / or operational relationship will be the same for each respective low-camber blade pair 710.

[0032] It should be understood that the above Figure 2 as well as Fig. 9 and Fig.10 The embodiments described in the context of can be combined with each other. That is, the blunt trailing edge 218 ( Figure 2 ) and a step change in radius (Δr) to implement a step change in the flow area of ​​the channel, such as in Fig. 9 and Fig.10 discussed in the context of .

[0033] Regardless of the specific implementation used to achieve the step change in flow area, for example, the step change can be configured to provide an increase in flow area in the range of about 30% to about 200% at the location where the step change is located.

[0034] Figure 5 Various example diagrams are shown for designing a shock wave system 302 that may be formed in a shock zone 204 that may be part of a disclosed supersonic diffuser, wherein the shock wave system 302 allows for an increase in the static temperature of a process fluid downstream of the shock wave system. Figure 5 As shown, in an exemplary embodiment, the respective intensities of successive shock waves in shock wave system 302 gradually decay as the shock wave system propagates in shock zone 204. For readers who wish to obtain more background information regarding the behavior of the shock wave system, reference is made to the paper “Flow Establishment of Precombustion Shock Trains in a Shock Tunnel” by Andrew N. Ridings and Michael K. Smart, published in 2017 by the American Institute of Aeronautics and Astronautics.

[0035] Figures 6 to 82 are cross-sectional views of other non-limiting example embodiments 110', 110", and 110'" respectively of the disclosed supersonic diffuser. As an example, the supersonic diffuser 110' has an outer wall 212 and an inner wall 214 that are parallel or approximately parallel to a centerline 216 passing through the blade area 202. As an example, the impact zone 204 can be configured to rotate a few degrees (e.g., up to about 10 to 15 degrees) toward the centerline, with a substantially constant area (e.g., height increase) for the corresponding passage for the process fluid.

[0036] By comparison, the supersonic diffuser 110 ( Figure 2 ), 110″ and 110″′ may each have appropriately contoured walls 212, 214 to suppress the bending effects that may exist in the annular passage defined by these walls. It should be understood that the supersonic diffuser 110 ( Figure 2 ), 110 ′, 110 ″ are each configured to provide discharge of process fluid in an axial direction (eg, coaxial pipe discharge). As an example, supersonic diffuser 110 ″′ is configured to provide discharge of process fluid in a radial direction after turning flow from an initial axial direction, as schematically represented by arrow 610 .

[0037] Without limitation, the meridional area distribution in one embodiment of a supersonic diffuser may be configured to account for boundary layer growth and increase the meridional area distribution by about 5% to about 15% through the blade area 202. In the mixing and subsonic diffusion region 206, in certain embodiments, the net divergence of the passage with an equivalent half angle of up to about 8 degrees may allow for effective total pressure recovery in the diffuser. In an exemplary embodiment, the ratio of the hub to tip radius of the corresponding blades in the blade area 202 may be in the range from about 0.80 to about 0.95, and the ratio of the pitch spacing to the axial chord may be between about 0.8 and about 1.0. In an exemplary embodiment, the length of the impact zone 204 may range from about eight times to about ten times the hydraulic diameter of the passage defined by the blade area (e.g., where the process fluid flow leaves the blade area).

[0038] Fig.11 and Fig.12 2 is a partial cross-sectional view of a further embodiment of the disclosed supersonic diffuser, which may include a corresponding shock attenuation structure located in the shock zone 204 near the outlet of the blade zone 202. For example, Fig.11 As shown, the supersonic diffuser 110 includes an array of prismatic triangular shock attenuation structures 910. These shock attenuation structures 910 may project radially across the flow path downstream of and aligned with the outlet of the passages of the blade section 202. Fig.11 and Fig.12 Shown in Figure 2 The blade area topology is discussed in the context of , but it should be understood that the shock attenuation structure may alternatively be used in any other of the aforementioned embodiments of the disclosed supersonic diffuser.

[0039] In another exemplary embodiment, Fig.12 As shown, supersonic diffuser 110 includes an array of circular shock-attenuating structures 1010. If optionally desired, arrays 910, 1010 may include multiple rows of shock-attenuating structures spaced apart in the axial direction to further enhance the performance of the diffuser in quickly and uniformly converting the supersonic velocity of the fluid into internal energy.

[0040] In an exemplary embodiment, the process fluid subjected to the thermochemical reaction may include ammonia to produce a mixture of ammonia and hydrogen. As will be appreciated by those skilled in the art, the mixture of ammonia and hydrogen constitutes a carbon-free fuel. In another exemplary embodiment, the process fluid subjected to the thermochemical reaction may include saturated hydrocarbons (e.g., propane, naphtha, or ethane) to produce olefins.

[0041] In an exemplary embodiment, the series of shock waves is effective to increase the static temperature of the process fluid downstream of the series of shock waves by at least ten percent (10%) within ten milliseconds (10 MS) without varying the static pressure by more than plus or minus twenty-five percent (25%).

[0042] Fig.13 is a plot obtained from an example model of the disclosed supersonic diffuser. The figure shows the spatial distribution of the static temperature of a process fluid initially flowing at supersonic speed from the vane region 202 of the diffuser to the impingement region 204 and finally to the mixing and subsonic diffusion region 206 of the diffuser.

[0043] In operation, the disclosed supersonic diffuser embodiments effectively achieve the desired increase in static temperature of the fluid to initiate certain thermochemical reactions. The disclosed embodiments demonstrate a robust and compact topology that can handle a wide range of backpressures while isolating upstream fluid flow conditions.

[0044] Although the exemplary embodiments of the present disclosure have been described in detail, those skilled in the art will understand that various changes, substitutions, variations and alterations may be made herein without departing from the spirit and scope of the disclosure in its broadest form.

[0045] Nothing in this application should be read as implying that any particular element, step, action, or function is an essential element that must be included within the scope of the claims. The scope of the subject matter of this patent is limited only by the claims that are issued. Furthermore, unless the exact phrase "means for..." is followed by a participle, none of the claims are intended to invoke a means-plus-function claim construction.

Claims

1. A supersonic diffuser, comprising: a blade region configured to define a passage having a flow area for flow of a process fluid at supersonic speeds, the blade region configured to define a step change in the flow area of ​​the passage; an impingement zone fluidly coupled to the blade zone for passage of a process fluid exiting the blade zone, the impingement zone being configured to support a shockwave system that increases a static temperature of a process fluid downstream of the shockwave system; as well as a mixing and subsonic diffuser region fluidly coupled to the impingement region, the mixing and subsonic diffuser region having a flow below Mach number one, the mixing and subsonic diffuser region being configured to decelerate process fluid from the impingement region to a reduced subsonic velocity prior to discharge of the process fluid through an outlet of the supersonic diffuser.

2. The supersonic diffuser according to claim 1, wherein: The blade section includes a pair of spaced-apart blades disposed between an outer wall and an inner wall of the supersonic diffuser, and wherein the pair of blades are configured to parallelize a flow direction of the process fluid along an axial direction.

3. The supersonic diffuser according to claim 2, wherein: Each of the pair of blades has a blunt trailing edge that circumferentially defines a step change in flow area of ​​the passage.

4. The supersonic diffuser according to claim 1, wherein: The step change in flow area of ​​the passage is located where the process fluid flow exits the blade area.

5. The supersonic diffuser according to claim 2, wherein: At least one of the outer wall and the inner wall has a step change in radius, and the step change in radius further defines a step change in the flow area of ​​the channel in the radial direction.

6. The supersonic diffuser according to claim 1, wherein: The flow area is located between an outer wall and an inner wall of the supersonic diffuser, wherein at least one of the outer wall and the inner wall has a step change in radius that radially defines a step change in the flow area of ​​the passage.

7. The supersonic diffuser according to claim 1, wherein: The blade section includes a pair of low-camber blades, each low-camber blade having a camber angle of 20 degrees or less, the pair of low-camber blades being positioned between an outer wall and an inner wall of the supersonic diffuser, and wherein the pair of low-camber blades are arranged to direct the process fluid flow to encounter a step change in flow area of ​​the passage.

8. The supersonic diffuser according to claim 7, wherein: At least one of the outer wall and the inner wall has a step change in radius that radially defines a step change in flow area of ​​the passage.

9. The supersonic diffuser according to claim 1, wherein: The step change increases the flow area by a range from 30% to 200% at the location where the process fluid flow exits the blade area.

10. The supersonic diffuser according to claim 1, wherein: The step change increase in flow area is located at the intersection of the blade region and the impact region downstream.

11. The supersonic diffuser according to claim 1, wherein: The impact zone has a constant flow area.

12. The supersonic diffuser according to claim 1, wherein: The length of the impingement zone is in the range of eight to ten times the hydraulic diameter of the passage defined by the blade area at the location where the process fluid flow exits the blade area.

13. The supersonic diffuser according to claim 1, wherein: The mixing and subsonic diffusion zone is configured to discharge the process fluid in one of the following directions: axially, radially, or in a direction including an axial component and a radial component.

14. The supersonic diffuser according to claim 1, wherein: As the shock wave system propagates in the shock zone, the respective intensities of successive shock waves in the shock wave system gradually decay.

15. The supersonic diffuser according to claim 1, wherein: The increase in the static temperature of the process fluid induces a thermochemical reaction in the process fluid configured to break apart molecules in the process fluid prior to discharge of the process fluid.

16. The supersonic diffuser according to claim 15, wherein: The process fluid subjected to the thermochemical reaction includes ammonia to produce a mixture of ammonia and hydrogen.

17. The supersonic diffuser according to claim 16, wherein: The mixture of ammonia and hydrogen constitutes a carbon-free fuel.

18. The supersonic diffuser according to claim 15, wherein: The process fluid subjected to the thermochemical reaction includes hydrocarbons to produce olefins.

19. The supersonic diffuser according to claim 1, wherein: The series of shock waves is effective to increase the static temperature of the process fluid downstream of the shock wave system by at least 10% within 10 milliseconds (10 mS) without varying the static pressure by more than plus or minus 25%.

20. The supersonic diffuser of claim 1, wherein: A ratio of a hub to a tip radius of a respective blade in the blade region is in the range of 0.80 to 0.95, and wherein a ratio of a pitch spacing to an axial chord of the respective blade is in the range of 0.8 to 1.

0.

21. The supersonic diffuser according to claim 2, wherein: The channel is one of a series of circumferentially arranged independent channels fluidly coupled to the impingement zone.

22. The supersonic diffuser according to claim 21, wherein: The spaced-apart pair of blades is one of a plurality of circumferentially positioned blade pairs that collectively define a series of circumferentially arranged passages fluidly coupled to the impingement zone.

23. The supersonic diffuser according to claim 7, wherein: The channel is one of a series of circumferentially arranged independent channels fluidly coupled to the impingement zone.

24. The supersonic diffuser of claim 23, wherein: The pair of low camber blades is one of a plurality of circumferentially positioned pairs of low camber blades that collectively define a series of circumferentially arranged passages fluidly coupled to the impingement zone.

25. A turbine operable to transfer thermal energy, the turbine having a supersonic diffuser according to claim 1.

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