Friction-free design of high-pressure cycle heat pump

Abstract

A heat pump includes a sealed housing divided into a primary housing volume and one or more secondary volumes. The heat pump includes a shaft. The heat pump includes a displacer coupled to the shaft and oscillating to produce a pressure gain between a high pressure phase and a low pressure phase. The heat pump includes one or more displacer rings, wherein the displacer rings are made of a material having thermal properties below a threshold. The heat pump includes an insert, where the insert is configured to form a perimeter of the main shell volume, where the insert is made of a material having thermal properties below the threshold. The heat pump includes one or more liners, wherein the one or more liners separate the primary shell volume from the one or more secondary volumes. The heat pump includes one or more gas bearings configured to prevent contact between the shaft and the sealed housing.

Description

[0001] CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 411,115, filed on September 29, 2022, under 35 U.S.C. §119(e), the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to heat pump systems, and more particularly, the present disclosure relates to frictionless operation of a heat pump. Background Art

[0004] Various types of bearings can be used to prevent side contact between the shaft and the housing. However, many of the bearings used are not suitable for operation in clean and / or high pressure environments due to the need for lubrication or to accommodate pressure differentials. Operating conventional bearing systems in clean and / or high pressure environments can result in significantly reduced component life due to excessive friction or other undesirable component wear conditions. Therefore, there is a need to provide solutions to provide suitable shaft stability and life in clean and / or high pressure environments. Summary of the invention

[0005] According to an embodiment of the present disclosure, a heat pump is disclosed. In an embodiment, the heat pump includes a sealed shell, wherein the sealed shell is divided into a main shell volume and one or more secondary volumes. In an embodiment, the heat pump includes a shaft, wherein the shaft is configured to be driven to cause the shaft to oscillate linearly within the sealed shell. In an embodiment, the heat pump includes a displacer, wherein the displacer is coupled to the shaft and oscillates within the main shell volume based on the oscillation of the shaft, wherein the oscillation of the displacer produces a pressure gain between a high pressure phase and a low pressure phase. In an embodiment, the heat pump includes one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main shell volume, wherein the one or more displacer rings are made of a displacer ring material, and the displacer ring material is selected so that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold. In an embodiment, the heat pump comprises an insert, wherein the insert is configured to form a perimeter of the primary shell volume, wherein the insert is made of an insert material, the insert material being selected so that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below the threshold, wherein the one or more displacer rings and the insert direct gas through the displacer. In an embodiment, the heat pump comprises one or more bushings, wherein the one or more bushings separate the sealed shell into the primary shell volume and the one or more secondary volumes. In an embodiment, the heat pump comprises one or more gas bearings configured to prevent contact between the shaft and the sealed shell, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by the pressure oscillations caused by the oscillations of the displacer.

[0006] According to an embodiment of the present disclosure, a system is disclosed. In an embodiment, the system includes a broadband plasma light source. In an embodiment, the system includes a heat pump configured to provide pressurized gas to the broadband plasma light source. In an embodiment, the heat pump includes a sealed shell, wherein the sealed shell is divided into a main shell volume and one or more secondary volumes. In an embodiment, the heat pump includes a shaft, wherein the shaft is configured to be driven to cause the shaft to oscillate linearly within the sealed shell. In an embodiment, the heat pump includes a displacer, wherein the displacer is coupled to the shaft and oscillates within the main shell volume based on the oscillation of the shaft, wherein the oscillation of the displacer produces a pressure gain between a high pressure phase and a low pressure phase. In an embodiment, the heat pump includes one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main shell volume, wherein the one or more displacer rings are made of a displacer ring material, and the displacer ring material is selected so that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold. In an embodiment, the heat pump comprises an insert, wherein the insert is configured to form a perimeter of the primary shell volume, wherein the insert is made of an insert material selected so that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below the threshold, wherein the one or more displacer rings and the insert direct gas through the displacer. In an embodiment, the heat pump comprises one or more bushings, wherein the one or more bushings divide the sealed shell into the primary shell volume and the one or more secondary volumes. In an embodiment, the heat pump comprises one or more gas bearings configured to prevent contact between the shaft and the sealed shell, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by the pressure oscillations caused by the oscillations of the displacer.

[0007] According to an embodiment of the present disclosure, a method for operating a heat pump is disclosed. In an embodiment, the method includes isolating one or more secondary volumes from a main shell volume by one or more bushings. In an embodiment, the method oscillates a displacer coupled to a shaft to cause a pressure change in the main shell volume, wherein the heat pump has a high pressure phase and a low pressure phase caused by oscillating the displacer. In an embodiment, the method supplies at least a first portion of the high pressure phase of the heat pump to a broadband plasma light source. In an embodiment, the method supplies at least a second portion of the high pressure phase of the heat pump to one or more gas bearings positioned in each of the one or more secondary volumes. In an embodiment, the method prevents contact between the shaft and the shell of the heat pump by the one or more gas bearings. In an embodiment, the method directs gas through the displacer via one or more displacer rings and inserts within the heat pump, wherein the gas directed through the displacer produces the high pressure phase of the heat pump, wherein the one or more displacer rings are coupled to the shaft and extend radially outward into the main shell volume, wherein the displacer rings are made of a displacer ring material, the displacer ring material being selected so that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold, wherein the insert is configured to form a perimeter of the main shell volume, wherein the insert is made of an insert material, the insert material being selected so that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below the threshold.

[0008] It should be understood that both the above general description and the following detailed description are exemplary and illustrative only and do not necessarily limit the present invention.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and together with the general description serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Those skilled in the art may better appreciate the numerous advantages of the present disclosure by referring to the accompanying drawings.

[0010] Figure 1 is a schematic cross-sectional view of a heat pump according to one or more embodiments of the present disclosure.

[0011] Figure 2 is a block diagram of a system according to one or more embodiments of the present disclosure.

[0012] Figure 3 is a flow chart of a method according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0013] Reference will now be made in detail to the disclosed objects illustrated in the accompanying drawings. The present disclosure has been particularly shown and described with respect to specific embodiments and specific features thereof. The embodiments described herein should be regarded as illustrative rather than limiting. It should be readily apparent to those skilled in the art that various changes and modifications may be made to the form and details without departing from the spirit and scope of the present disclosure.

[0014] The extended operation of pistons and / or linear axes in clean and sealed (e.g., pressurized) environments can cause problems. Typical solutions for pistons (e.g., in applications such as engines, piston pumps, or the like) include bearings (e.g., ball bearings) and / or bushings. Bearings and / or bushings require active lubrication (e.g., grease) to extend their life and prevent problems caused by excessive friction. However, lubrication (e.g., grease) suitable for non-clean environments may not be suitable for use in clean environments. Therefore, bearings and / or bushings operating in clean environments can use dry lubricants or no lubrication. However, bearings and / or bushings using dry lubricants or no lubrication experience significantly limited life.

[0015] In certain applications, magnetic bearings can be used to provide frictionless stabilization suitable for clean environments. However, the applications of magnetic bearings are generally limited to rotational stabilization. Magnetic bearings can sometimes be suitable for other uses, however, making magnetic bearings suitable for uses related to linear axis stabilization can be extremely difficult.

[0016] Similarly, conventional piston rings (e.g., for sealing pistons and compensating for thermal expansion) also have problems with operating in a clean environment in conjunction with a heat pump. Precision mechanical systems designed to operate in a clean environment (cleanless mechanical piston pumps) typically use temperature stabilization to minimize expansion and thus limit the clearance between moving components. In addition, lubricant-free operation is typically used, but it results in a shortened life below reasonable limits for a given application. However, for heat pumps, this temperature stabilization is not feasible due to the necessary temperature difference between the hot and cold sides of the sealed housing. Finally, the use of very clean vacuum-compatible greases is not feasible due to the temperature range associated with the operation of heat pumps. Therefore, conventional piston rings may not be suitable for use in conjunction with heat pumps.

[0017] The present disclosure discloses a system for operating a heat pump in a clean and high pressure environment with a significantly extended life, especially compared to other techniques previously described herein. More specifically, the present disclosure presents a heat pump with frictionless linear axis operation in a clean high pressure environment. This heat pump can be used in conjunction with a broadband plasma (BBP) flow-based light source. More generally, the heat pump can be used with a plasma tube light source, such as a light source in which a plasma is placed in a gas flow, such as a wind tunnel.

[0018] Reference Figures 1 to 2According to one or more embodiments of the present disclosure, an implementation of a frictionless heat pump 100 suitable for use in clean and high pressure environments is disclosed.

[0019] Figure 1 is a schematic cross-sectional view of a heat pump 100 according to one or more embodiments of the present disclosure. A possible design of a heat pump is disclosed in U.S. Patent No. 11,450,521 issued on September 20, 2022, the entire text of which is incorporated herein by reference.

[0020] In an embodiment, the heat pump 100 includes a displacer 102 in a sealed shell 104. The displacer 102 may be a body configured to move linearly (e.g., upward and downward) in the sealed shell 104. The displacer 102 may be designed to allow gas to flow through the displacer, for example, by incorporating a channel. The displacer 102 may further include one or more channels (e.g., vertical channels). For example, the channel may be designed to allow gas to flow through the channel when the heat pump 100 is in operation (e.g., when the displacer 102 oscillates). The displacer 102 may combine two functions: isolating the gas in the hot and cold ends of the sealed shell 104 and providing heat exchange with the gas passing through it. In order to meet these requirements, the displacer 102 is usually made of several components, one of which may be a heat accumulator (not drawn) (e.g., a relatively small component having high thermal conductivity and high heat capacity and placed at the core of the displacer 102), and the remainder of the displacer 102 may be made of a lightweight material exhibiting low thermal conductivity and low heat capacity. In an embodiment, the heat accumulator may be made of a multilayer copper mesh. In addition, the displacer 102 may be made of a material having a high coefficient of thermal expansion. Because the displacer 102 may have low thermal conductivity and capacity and have a high coefficient of thermal expansion, the displacer 102 may exhibit relatively large thermal expansion during operation of the heat pump 100. As a non-limiting example, the displacer 102 may be made of Teflon. In this way, the displacer 102 may include components with various thermal conductivities (e.g., the heat accumulator may have a high thermal capacity and the remainder of the displacer 102 may have a low thermal capacity). It should be noted that for the purposes of this application, reference will be made to the entire displacer 102 rather than to individual components.

[0021] The displacer 102 may be configured to move gas between the hot and cold ends of the sealed vessel 104. Moving gas between the hot and cold ends of the sealed vessel 104 may create a pressure gain between the high pressure phase and the low pressure phase.

[0022] In an embodiment, the heat pump 100 includes a sealed shell 104. The sealed shell 104 can enclose a main shell volume 106 through which the displacer 102 linearly translates. The sealed shell 104 can have a significant temperature difference on both sides of the sealed shell 104 (e.g., the top of the sealed shell 104 can be very cold and the bottom of the sealed shell 104 can be very hot, or vice versa). The large temperature difference between the two sides of the sealed shell 104 can cause significant thermal expansion. It should be noted that because the displacer 102 does not generate a large pressure drop due to its oscillation, only moderate sealing and driving forces are required within the heat pump 100.

[0023] In an embodiment, the heat pump 100 includes a shaft 108. The displacer 102 may be coupled to the shaft 108 such that linear motion of the shaft 108 drives the displacer 102. Furthermore, the shaft 108 may be configured to be driven such that the heat pump 100 may be maintained as a sealed system (e.g., the shaft 108 remains within the sealed housing 104 during operation of the heat pump 100). For example, the shaft 108 may be magnetically driven. In this manner, the shaft 108 may have one or more magnets 110 coupled thereto.

[0024] The magnets 110 may correspond to one or more magnetic drives 112. The magnetic drives 112 may be positioned outside the heat pump 100 (e.g., outside the sealed housing 104) and translate linearly. The magnets 110 coupled to the shaft 108 may be attracted to the magnetic drives 112 in a manner that causes the shaft 108 to translate in a manner that corresponds to the translation of the magnetic drives 112. The magnetic drives 112 may cause the shaft 108 (e.g., and thus the coupled displacer 102) to move periodically. For example, the shaft 108 may oscillate once per second.

[0025] In an embodiment, the heat pump 100 includes one or more displacer rings 114. Each displacer ring 114 may be directly coupled to the displacer 102. The displacer ring 114 may further extend radially outward through the main shell volume 106. The displacer ring 114 may be made of a low expansion material (e.g., a material whose size is not affected by temperature changes). In addition, the displacer ring 114 may be made of a material that exhibits both low expansion and low conductivity. For example, the displacer ring 114 may be made of a material having a low displacer ring thermal conductivity coefficient and / or a low displacer ring thermal expansion coefficient (e.g., but not limited to glass, machinable glass (e.g., MACOR), ceramic, or the like). As an illustration, MACOR has a thermal conductivity of 1.46 W / (K*m) compared to 15 W / (K*m) of stainless steel. Therefore, when using a material such as machinable glass, the heat flow between the top of the main shell volume 106 and the bottom of the main shell volume 106 and the expansion potential of the displacer ring 114 can be significantly reduced.

[0026] In this manner, the displacer ring 114 can be manufactured with a diameter that is slightly smaller than the diameter of the main housing volume 106 because the diameter of the displacer ring 114 does not change significantly with temperature changes (e.g., without contact due to expansion, the displacer ring 114 can be nearly the same size as the main housing volume 106). It should be noted that thermal expansion of the shaft 108 can be minimized due to the small diameter of the shaft.

[0027] The displacer ring 114 may be positioned at various locations on the displacer 102. For example, the displacer ring 114 may be placed so that it is on one or more sides of the displacer 102 (e.g., above the displacer 102 or below the displacer 102). As another example, the displacer ring 114 may be placed at a location along the displacer 102 (e.g., the displacer 102 is made of two or more discrete pieces with one or more displacer rings 114 therebetween). As another example, the displacer ring 114 may be placed at one or more ends of the displacer 102.

[0028] In an embodiment, the heat pump 100 includes an insert 116. The insert 116 can be a hollow cylinder and can be concentrically mounted within the sealed shell 104 (e.g., the insert forms the perimeter of the main shell volume 106). In this way, the displacer ring 114 can be configured to be slightly smaller than the insert 116 (e.g., the displacer ring 114 can be slightly smaller than the insert 116 rather than slightly smaller than the main shell volume 106). The insert 116 can be made of a material having a low insert thermal conductivity coefficient and / or a low insert thermal expansion coefficient. For example, the insert 116 can be made of a material such as, but not limited to, glass, machinable glass (e.g., MACOR), ceramic, or the like (e.g., the insert 116 can be made of the same material as the displacer ring 114 or a different material than the displacer ring 114). It should be noted that this insert 116 can be used because there is no pressure difference between the areas in the main shell volume 106.

[0029] The insert 116, in addition to the displacer ring 114, can also result in a stable gap 118 (e.g., because low expansion materials are used on both sides, the gap 118 is not susceptible to significant expansion and / or contraction of the material). Furthermore, the insert 116, in addition to the displacer ring 114, can also result in enhanced thermal insulation of the heat pump 100. Because both the insert 116 and the displacer ring 114 can be made of low conductivity materials, the heat flow between the high and low temperature areas of the main shell volume 106 can be reduced and heat can be prevented from escaping the heat pump 100 through the sealed shell 104. In this way, adding the insert 116 and / or the displacer ring 114 can improve the efficiency and / or performance of the heat pump 100.

[0030] In addition, the displacer ring 114 and the insert 116 can minimize the gap 118 therebetween. Thus, oscillating the displacer 102 and the displacer ring 114 can force the gas to pass through the displacer 102 and exchange heat (e.g., the gas flows only (or almost only) through the channels of the displacer 102 rather than around the displacer 102). In addition, the displacer ring 114 can isolate the hot end of the heat pump 100 from the cold end of the heat pump 100. The radial extension of the displacer ring 114 can compensate for thermal expansion of other components of the heat pump 100 between the displacer 102 and the cold end of the main shell volume 106 and the hot end of the main shell volume.

[0031] The material used for the displacer ring 114 and / or the insert 116 can be selected so that the thermal conductivity and / or the coefficient of thermal expansion is below a threshold value. For example, the threshold value can be selected so that expansion of the displacer ring 114 and / or the expansion of the insert 116 (e.g., expansion caused by temperature differences within the heat pump 100) does not result in contact with any solid surface (e.g., to prevent friction). Similarly, the size of the displacer ring 114 and / or the insert 116 can be selected based on the thermal conductivity and / or the coefficient of thermal expansion to minimize expansion of the heat pump 100 and maximize thermal insulation.

[0032] Efficient operation of the heat pump 100 may be based on gas flowing through the passages of the displacer 102 and thus through the regenerator (e.g., if the regenerator is manufactured as a separate component) rather than around the displacer 102. Thus, a precision displacer ring 114 and / or insert 116 may be used to minimize the gap 118. For example, a small gap 118 may result in nearly all of the gas in the main shell volume 106 flowing through the passages of the displacer 102 rather than around the displacer 102.

[0033] In an embodiment, the heat pump 100 includes one or more secondary volumes 120 (e.g., the sealed shell 104 creates one or more secondary volumes 120 in addition to the primary shell volume 106). For example, there may be a secondary volume 120 at the top of the heat pump 100 and a secondary volume 120 at the bottom of the heat pump 100. The secondary volumes 120 may be configured for linear movement of the shaft 108 while the displacer 102 remains within the primary shell volume 106.

[0034] In an embodiment, the heat pump 100 includes one or more gas bearings 122. For example, each secondary volume 120 may include a gas bearing 122. The gas bearings 122 may operate using the pressure gain generated by the heat pump 100.

[0035] In an embodiment, the heat pump 100 includes one or more bushings 124. For example, each secondary volume 120 can be delimited from the main shell volume 106 by a bushing 124. The bushing 124 can form a tight fit with the shell 104 and / or the shaft 108. In this way, gas can be prevented from traveling between the main shell volume 106 and the secondary volumes 120. The bushing 124 can further divide (e.g., separate) the sealed shell 104 into the main shell volume 106 and one or more secondary volumes 120.

[0036] In an embodiment, the heat pump 100 includes a high pressure supply 126 and a low pressure supply 128. The pressures of the high pressure supply 126 and the low pressure supply 128 may be caused by a pressure gain caused by the heat pump 100. For example, the high pressure supply 126 may be coupled to a high pressure location of the heat pump 100, such as an output of the heat pump 100. As another example, the low pressure supply 128 may be coupled to a low pressure location of the heat pump 100, such as an input of the heat pump 100. High pressure gas may be supplied to the center of the gas bearing 122 (e.g., to form a thin layer of gas to prevent contact between the shaft 108 and the sealed shell 104).

[0037] It should be noted that while the pressure in the main housing volume 106 varies between a high pressure phase and a low pressure phase (e.g., the main housing volume 106 oscillates between a high pressure phase and a low pressure phase), the pressure in the secondary volume 120 may remain stable or constant (e.g., or nearly constant). The pressure in the secondary volume 120 may remain constant due to the bushing 124. The bushing 124 may be configured such that it significantly reduces the gas flow between the main housing volume 106 and the secondary volume 120 (e.g., by reducing the space between the main housing volume 106 and the secondary volume 120 for gas to flow around the shaft). Because the secondary volume 120 has high pressure gas therein, the bushing 124 does not have to completely block the gas flow between the main housing volume 106 and the secondary volume 120. Instead, the bushing 124 only needs to form a precise aperture to leave a small space between the bushing 124 and the shaft 108 (e.g., for preventing friction between the shaft 108 and the bushing 124). Furthermore, it should be noted that the pressure drop may be as high as the amount of the pressure gain in the heat pump 100 and the air flow may be significantly lower than the flow rate of the heat pump 100 .

[0038] The gas bearing 122 can operate by creating a gas layer (e.g., high pressure gas) between two surfaces (e.g., the shaft 108 and the sealed shell 104). This gas layer can prevent the two surfaces from contacting during the linear translation of the shaft 108, so that the shaft 108 can operate in a frictionless environment (e.g., below a certain speed threshold, the friction due to the gas is negligible). In addition, because no lubrication is required (e.g., because there is no contact), the gas bearing 122 can be suitable for use in a clean environment. The bushing 124 can also cause a stable pressure in the secondary volume 120 (e.g., the volume where the gas bearing 122 is located), which can make the gas bearing 122 suitable for operation in a high pressure environment.

[0039] The high pressure supply 126 and the low pressure supply 128 can be used to operate the gas bearing 122 (e.g., the gas bearing 122 can operate based on the pressure difference between the input of the heat pump 100 and the output of the heat pump 100). The gas flow required to operate the gas bearing 122 can be significantly less than the gas flow generated by the heat pump 100, and thus the gas bearing 122 can operate (e.g., create a frictionless environment) while the heat pump 100 maintains its operating capacity. The gas used within the heat pump 100 and for the gas bearing 122 can be any gas. For example, the gas can be argon (Ar).

[0040] Figure 2 is a block diagram of a system 200 according to one or more embodiments of the present disclosure.

[0041] In an embodiment, the system 200 includes a heat pump 100 .

[0042] In an embodiment, the system 200 includes a broadband plasma (BBP) light source 202. However, it should be noted that the heat pump 100 disclosed herein can be used with any device that requires the operation of the heat pump 100. The heat pump 100 can be configured to provide a pressurized gas to the BBP light source 202. For example, the BBP light source 202 can be configured to operate based in part on high pressure gas. For example, the BBP light source 202 requires pressurized gas to power the laser within the BBP light source 202. Therefore, the heat pump 100 can provide this pressurized gas to the BBP light source 202. This configuration is disclosed in U.S. Patent No. 11,450,521, issued on September 20, 2022, previously cited herein, the entire contents of which are incorporated herein by reference.

[0043] Furthermore, the BBP light source 202 can be used for any purpose known in the art. For example, the BBP light source 202 can be used for metrology.

[0044] Figure 3 is a flow chart of a method 300 according to one or more embodiments of the present disclosure. Applicants note that the embodiments and implementation techniques previously described herein in the context of heat pump 100 and / or system 200 should be interpreted as extending to method 300. However, it should be further noted that method 300 is not limited to the architecture of heat pump 100 and / or system 200.

[0045] In an embodiment, method 300 includes step 302 of isolating one or more secondary volumes from a main housing volume by one or more bushings. For example, the bushing may form a tight aperture around a shaft that penetrates the one or more secondary volumes and the main housing volume. Because the secondary volumes may be under high pressure and there may be little room for gas to escape between the bushing and the shaft, the bushing may effectively isolate the one or more secondary volumes from the main housing volume.

[0046] In an embodiment, method 300 includes step 304 of oscillating a displacer coupled to a shaft to vary pressure within the main housing volume, wherein the heat pump has a high pressure output and a low pressure input caused by the oscillating displacer.

[0047] In an embodiment, method 300 includes step 306 of supplying at least a first portion of the high pressure output of the heat pump to the broadband plasma light source. For example, a large portion of the pressure gain generated via the oscillating displacer can be utilized by the broadband plasma light source.

[0048] In an embodiment, method 300 includes step 308 of supplying at least a second portion of the high pressure output of the heat pump to one or more gas bearings positioned within each of the one or more secondary volumes. For example, the second portion of the high pressure output can be used by the gas bearings to generate a gas film. In addition, the gas escaping the film can be redirected into the low pressure input of the heat pump and re-pressurized.

[0049] In an embodiment, method 300 includes step 310 of preventing contact between the shaft and the housing of the heat pump by one or more gas bearings. For example, a thin film of pressurized gas can be used to prevent contact between the shaft and the housing. In this way, the heat pump can operate without friction (e.g., negligible friction) between the shaft and the housing.

[0050] In an embodiment, method 300 includes step 312 of directing gas through a displacer through one or more displacer rings and inserts within a heat pump, wherein directing gas through the displacer produces a high pressure output of the heat pump, wherein the one or more displacer rings are coupled to a shaft and extend radially outward into a main shell volume, wherein the displacer rings are made of a displacer ring material selected such that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold, wherein an insert is configured to form a perimeter of the main shell volume, wherein the insert is made of an insert material selected such that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below a threshold. For example, the displacer and insert may be configured such that they minimize a gap within the main shell volume (e.g., a gap between a displacer ring and an insert). Minimizing this gap may result in improved performance of the heat pump due to substantially all of the gas within the heat pump flowing through the displacer.

[0051] The present invention sometimes illustrates different components contained in other components or connected to other components. It should be understood that such depicted architecture is for demonstration only, and in fact, many other architectures that realize the same function can be implemented. In terms of concept, any arrangement of components that realize the same function is effectively "associated" to realize the desired function. Therefore, no matter how the architecture or intermediate components are, any two components combined to realize a specific function herein can be regarded as being "associated" with each other to realize the desired function. Similarly, any two components so associated can also be regarded as being "connected" or "coupled" to realize the desired function, and any two components that can be so associated can also be regarded as "coupling" with each other to realize the desired function. The specific examples of "coupling" include but are not limited to physically interactable and / or physically interactive components and / or wirelessly interactive and / or wirelessly interactive components and / or logically interactive and / or logically interactive components.

[0052] It is believed that the present disclosure and its many attendant advantages will be understood from the above description, and it should be appreciated that various changes may be made to the form, structure and arrangement of components without departing from the present disclosure or sacrificing all of its material advantages. The described forms are for illustration only and the appended claims are intended to cover and encompass such changes. Furthermore, it should be understood that the invention is defined by the appended claims.

Claims

1. A heat pump, comprising: a sealed shell, wherein the sealed shell is divided into a main shell volume and one or more secondary volumes; a shaft, wherein the shaft is configured to be driven to cause the shaft to oscillate linearly within the sealed housing; a displacer, wherein the displacer is coupled to the shaft and oscillates within the main housing volume based on oscillations of the shaft, wherein oscillations of the displacer produce a pressure gain between a high pressure phase and a low pressure phase; one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main housing volume, wherein the one or more displacer rings are made of a displacer ring material selected such that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold; an insert, wherein the insert is configured to form a perimeter of the main housing volume, wherein the insert is made of an insert material selected such that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below the threshold, wherein the one or more displacer rings and the insert direct gas through the displacer; one or more liners, wherein the one or more liners separate the sealed shell into the primary shell volume and the one or more secondary volumes; and One or more gas bearings configured to prevent contact between the shaft and the sealed housing, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by the pressure oscillations caused by the oscillations of the displacer. 2 . The heat pump of claim 1 , wherein the shaft comprises one or more magnets coupled to the shaft.

3. The heat pump of claim 2, wherein the shaft is magnetically driven via one or more external magnetic drivers and the one or more magnets coupled to the shaft.

4. The heat pump of claim 1, wherein the one or more secondary volumes are maintained at a constant pressure.

5. The heat pump of claim 1, wherein the primary housing volume varies between two or more pressures.

6. The heat pump of claim 1, wherein one or more of the insert or the one or more displacer rings are made of one of glass, machinable glass, or ceramic.

7. The heat pump of claim 1, wherein at least one of the one or more displacer rings is positioned at one or more ends of the displacer.

8. The heat pump of claim 1, wherein the displacer is formed from two or more discrete pieces.

9. The heat pump of claim 8, wherein at least one of the one or more displacer rings is positioned between the two or more discrete pieces of the displacer.

10. A system comprising: Broadband plasma light source; and a heat pump configured to provide a pressurized gas to the broadband plasma light source, the heat pump comprising: a sealed shell, wherein the sealed shell is divided into a main shell volume and one or more secondary volumes; a shaft, wherein the shaft is configured to be driven to cause the shaft to oscillate linearly within the sealed housing; a displacer, wherein the displacer is coupled to the shaft and oscillates within the main housing volume based on oscillations of the shaft, wherein oscillations of the displacer produce a pressure gain between a high pressure phase and a low pressure phase; one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main housing volume, wherein the one or more displacer rings are made of a displacer ring material selected such that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold; an insert, wherein the insert is configured to form a perimeter of the main housing volume, wherein the insert is made of an insert material selected such that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below the threshold, wherein the one or more displacer rings and the insert direct gas through the displacer; one or more liners, wherein the one or more liners separate the sealed shell into the primary shell volume and the one or more secondary volumes; and One or more gas bearings configured to prevent contact between the shaft and the sealed housing, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by the pressure oscillations caused by the oscillations of the displacer.

11. The heat pump of claim 10, wherein the shaft includes one or more magnets coupled to the shaft.

12. The heat pump of claim 11, wherein the shaft is magnetically driven via one or more external magnetic drivers and the one or more magnets coupled to the shaft.

13. The heat pump of claim 10, wherein the one or more secondary volumes are maintained at a constant pressure.

14. The heat pump of claim 10, wherein the primary housing volume varies between two or more pressures.

15. The heat pump of claim 10, wherein one or more of the insert or the one or more displacer rings are made of one of glass, machinable glass, or ceramic.

16. The heat pump of claim 10, wherein at least one of the one or more displacer rings is positioned at one or more ends of the displacer.

17. The heat pump of claim 10, wherein the displacer is formed from two or more discrete pieces.

18. The heat pump of claim 17, wherein at least one of the one or more displacer rings is positioned between the two or more discrete pieces of the displacer.

19. A method of operating a heat pump, comprising: isolating one or more secondary volumes from the main housing volume by one or more bushings; oscillating a displacer coupled to a shaft to cause a pressure change within the main shell volume, wherein the heat pump has a high pressure phase and a low pressure phase caused by oscillating the displacer; supplying at least a first portion of the high pressure phase of the heat pump to a broadband plasma light source; supplying at least a second portion of the high pressure phase of the heat pump to one or more gas bearings positioned within each of the one or more secondary volumes; preventing contact between the shaft and a housing of the heat pump by the one or more gas bearings; Gas is directed through the displacer by one or more displacer rings and inserts within the heat pump, wherein the gas directed through the displacer produces the high pressure phase of the heat pump, wherein the one or more displacer rings are coupled to the shaft and extend radially outward into the main shell volume, wherein the displacer rings are made of a displacer ring material, the displacer ring material being selected so that at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient is below a threshold, wherein the insert is configured to form a perimeter of the main shell volume, wherein the insert is made of an insert material, the insert material being selected so that at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient is below the threshold.

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