Frictionless design of high pressure recirculation heat pumps.

Abstract

The heat pump 100 includes a sealed housing 104 divided into a main housing volume 106 and one or more secondary volumes 120. The heat pump 100 includes a shaft 108. The heat pump includes a displacer 102 coupled to the shaft 108 and reciprocating to create a pressure gain between a high-pressure phase and a low-pressure phase. The heat pump includes one or more displacer rings 114, each made from a material having a thermal property less than a threshold value. The heat pump 100 includes an insert 116 configured to form a perimeter of the main housing volume 106, the insert 116 being made from a material having a thermal property less than a threshold value. The heat pump 100 includes one or more bushings 124, each separating the main housing volume 106 from the one or more secondary volumes 120. The heat pump 100 includes one or more gas bearings 122 configured to prevent contact between the shaft 108 and the sealed housing 104 .

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to heat pump systems, and more particularly to frictionless operation of heat pumps. [Background technology]

[0002] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 63 / 411,115, filed September 29, 2022, which is incorporated herein by reference in its entirety.

[0003] Various bearings may be used to keep the shaft from contacting the housing side. 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 an appropriate pressure differential. Operating conventional bearing systems in clean and / or high-pressure environments can result in significantly reduced component life due to excessive friction, leading to less-than-ideal conditions for component wear. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 6,506,030 [Patent Document 2] U.S. Patent Application Publication No. 2010 / 0212311 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, there is a need to provide a solution that provides suitable shaft stability and life in clean and / or high pressure environments. [Means for solving the problem]

[0006] According to an embodiment of the present disclosure, a heat pump is disclosed. In an embodiment, the heat pump includes a sealed housing, the sealed housing being divided into a main housing volume and one or more secondary volumes. In an embodiment, the heat pump includes a shaft configured to be driven to linearly reciprocate the shaft within the sealed housing. In an embodiment, the heat pump includes a displacer, the displacer coupled to the shaft and reciprocating within the main housing volume based on the reciprocation of the shaft, the reciprocation of the displacer creating 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 coupled to the displacer and extending radially outward into the main housing volume, the one or more displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient that is less than a threshold value. In embodiments, the heat pump includes an insert configured to form a periphery of the main housing volume, the insert being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient less than a threshold, and the one or more displacer rings and insert direct gas through the displacer. In embodiments, the heat pump includes one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and one or more secondary volumes. In embodiments, the heat pump includes one or more gas bearings configured to prevent contact between the shaft and the sealed housing, the one or more gas bearings configured to operate based on high-pressure and low-pressure phases created by pressure oscillations caused by the reciprocating motion of the displacer.

[0007] 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 housing, the sealed housing being divided into a main housing volume and one or more secondary volumes. In an embodiment, the heat pump includes a shaft, the shaft being configured to be driven to linearly reciprocate within the sealed housing. In an embodiment, the heat pump includes a displacer, the displacer coupled to the shaft and reciprocating within the main housing volume based on the reciprocation of the shaft, the reciprocation of the displacer creating 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 coupled to the displacer and extending radially outward into the main housing volume, the one or more displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient that is less than a threshold value. In embodiments, the heat pump includes an insert configured to form a periphery of the main housing volume, the insert being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient less than a threshold, and the one or more displacer rings and insert direct gas through the displacer. In embodiments, the heat pump includes one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and one or more secondary volumes. In embodiments, the heat pump includes one or more gas bearings configured to prevent contact between the shaft and the sealed housing, the one or more gas bearings configured to operate based on high-pressure and low-pressure phases created by pressure oscillations caused by the reciprocating motion of the displacer.

[0008] According to an embodiment of the present disclosure, a method of heat pump operation is disclosed. In an embodiment, the method includes isolating one or more secondary volumes from a main housing volume with one or more bushings. In an embodiment, the method includes reciprocating a displacer coupled to a shaft to vary the pressure within the main housing volume, the heat pump having a high-pressure phase and a low-pressure phase caused by the reciprocating displacer. In an embodiment, the method includes supplying 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 includes supplying at least a second portion of the high-pressure phase of the heat pump to one or more gas bearings disposed within each of the one or more secondary volumes. In an embodiment, the method includes preventing contact between the shaft and the heat pump housing with the one or more gas bearings. In an embodiment, a method includes directing gas through a displacer with one or more displacer rings and inserts within a heat pump, the gas directed through the displacer creating a high-pressure phase of the heat pump, the one or more displacer rings coupled to a shaft and extending radially outward into a main housing volume, the displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient that is less than a threshold value, and the inserts being configured to form a periphery of the main housing volume, the inserts being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient that is less than a threshold value.

[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not necessarily restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description, serve to explain the principles of the invention.

[0010] The many advantages of the present disclosure may be better understood by those skilled in the art with reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional schematic diagram of a heat pump according to one or more embodiments of the present disclosure. [Figure 2] FIG. 1 is a block diagram of a system in accordance with one or more embodiments of the present disclosure. [Figure 3] 1 is a flow diagram of a method according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Reference will now be made in detail to the disclosed subject matter, as illustrated in the accompanying drawings. The present disclosure has been shown and described in detail with respect to several embodiments and specific features thereof. The embodiments described herein are intended to be illustrative and not limiting. It will be readily apparent to those skilled in the art that various changes and modifications in form and detail can be made therein without departing from the spirit and scope of the present disclosure.

[0013] Extended operation of pistons and / or linear shafts in clean, sealed (e.g., pressurized) environments can pose problems. Typical solutions for pistons (e.g., in applications such as engines, piston pumps, etc.) include bearings (e.g., ball bearings) and / or bushings. The bearings and / or bushings may require active lubrication (e.g., grease) to extend their life and prevent problems caused by excessive friction. However, lubrication (e.g., grease) that is suitable for non-clean environments may not be suitable for use in clean environments. Therefore, bearings and / or bushings operating in clean environments may use dry lubrication or no lubrication. However, bearings and / or bushings that use dry lubrication or no lubrication can have significantly limited lifespans.

[0014] In some applications, magnetic bearings can be used to provide frictionless stabilization suitable for clean environments. However, magnetic bearing applications are generally limited to rotational stabilization. While magnetic bearings can often be adapted for other applications, adapting magnetic bearings for linear axis stabilization applications can be prohibitively difficult.

[0015] Similarly, conventional piston rings (e.g., for sealing the piston and compensating for thermal expansion) may similarly have problems when operating in conjunction with heat pumps in clean environments. Typically, precision mechanical systems designed to operate in clean environments (no clean mechanical piston pumps exist) use temperature stabilization to minimize expansion and consequently limit clearances between moving components. The use of lubrication-free operation is also common, resulting in unreasonably reduced lifespans for a given application. However, for heat pumps, such temperature stabilization is not possible due to the essential temperature difference between the hot and cold sides of the sealed enclosure. Finally, the use of highly clean, vacuum-compatible greases is not possible in the temperature ranges associated with heat pump operation. Therefore, conventional piston rings may be unsuitable for heat pump applications.

[0016] The present disclosure discloses a system for operating a heat pump in a clean, high-pressure environment, particularly with a significantly improved lifespan compared to other technologies previously described herein. More specifically, the present disclosure presents a heat pump with frictionless, direct-acting shaft operation in a clean, high-pressure environment. Such a heat pump can be used in conjunction with broadband plasma (BBP) flow-based light sources. More broadly, the heat pump can be used with plasmatron light sources (e.g., light sources in which a plasma is placed within a gas flow (e.g., a wind tunnel)).

[0017] 1 and 2, in accordance with one or more embodiments of the present disclosure, an implementation of a frictionless heat pump 100 suitable for use in clean, high-pressure environments is disclosed.

[0018] 1 is a cross-sectional schematic diagram of a heat pump 100 according to one or more embodiments of the present disclosure. Possible designs for the heat pump are disclosed in U.S. Patent No. 11,450,521, issued September 20, 2022, the entirety of which is incorporated herein by reference.

[0019] In an embodiment, the heat pump 100 includes a displacer 102 within a sealed housing 104. The displacer 102 may be a body configured to move linearly (e.g., up and down) within the sealed housing 104. The displacer 102 may be designed to allow gas flow therethrough, for example, by incorporating a flow path. The displacer 102 may further include one or more flow paths (e.g., vertical flow paths). For example, the flow paths may be designed to allow gas flow therethrough when the heat pump 100 is in operation (e.g., when the displacer 102 is oscillating). The displacer 102 may combine two functions: isolating gas at the hot and cold ends of the sealed housing 104 and providing heat exchange with gas passing through the displacer 102. To meet these requirements, the displacer 102 is often made from several components, one of which may be a regenerator (not shown) (e.g., a relatively small part with high thermal conductivity and high heat capacity located in the center of the displacer 102), while the remainder of the displacer 102 may be made from a lightweight material exhibiting low thermal conductivity and low heat capacity. In an embodiment, the regenerator may be made from multi-layered copper mesh. Additionally, the displacer 102 may be made from a material with a large thermal expansion coefficient. Because the displacer 102 may have low thermal conductivity and heat capacity, and because it has a large thermal expansion coefficient, 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 from Teflon. In this manner, the displacer 102 may include components with different thermal conductivities (e.g., the regenerator may have a high heat capacity, while the remainder of the displacer 102 may have a low heat capacity). It should be noted that for purposes of this application, the displacer 102 will be referred to as a whole rather than referring to individual components.

[0020] The displacer 102 can be configured to move gas between a hot end and a cold end of the sealed housing 104. By moving gas between the hot end and the cold end of the sealed housing 104, a pressure gain between a high pressure phase and a low pressure phase can be created.

[0021] In an embodiment, the heat pump 100 includes a sealed housing 104. The sealed housing 104 can enclose a main housing volume 106 through which the displacer 102 translates linearly. The sealed housing 104 can have a large temperature difference on either side of the sealed housing 104 (e.g., the top of the sealed housing 104 can be very cold and the bottom of the sealed housing 104 can be very hot, or vice versa). The large temperature difference between the two sides of the sealed housing 104 can cause large thermal expansion. Note that only gentle sealing and driving forces are required within the heat pump 100 because the displacer 102 does not create a large pressure drop as it shuttles back and forth.

[0022] 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. As such, the shaft 108 may have one or more magnets 110 coupled to the shaft 108.

[0023] The magnet 110 can correspond to one or more magnetic drivers 112. The magnetic drivers 112 can be located outside the heat pump 100 (e.g., outside the sealed housing 104) and can translate linearly. The magnet 110 coupled to the shaft 108 can be attracted to the magnetic drivers 112 such that the shaft 108 is translated in a manner corresponding to the translation of the magnetic drivers 112. The magnetic drivers 112 can cause periodic motion of the shaft 108 (e.g., of the coupled displacer 102). For example, the shaft 108 may reciprocate once per second.

[0024] 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 rings 114 may also extend radially outward through the main housing volume 106. The displacer rings 114 may be made from a low-expansion material (e.g., a material whose size is not affected by changes in temperature). Additionally, the displacer rings 114 may be made from a material that exhibits both low expansion and low conductivity characteristics. For example, the displacer rings 114 may be made from a material with a low displacer thermal conductivity coefficient and / or a low displacer thermal expansion coefficient, such as, but not limited to, glass, machinable glass (e.g., MACOR), ceramic, etc. Illustratively, MACOR has a thermal conductivity of 1.46 W / (K*m), compared to 15 W / (K*m) for stainless steel. Therefore, using a material such as machinable glass can greatly reduce the flow of heat between the top of the main housing volume 106 and the bottom of the main housing volume 106, and at the same time, can greatly reduce the possibility of the displacer ring 114 expanding.

[0025] In this manner, displacer ring 114 can be manufactured with a diameter slightly smaller than the diameter of main housing volume 106 because the diameter of displacer ring 114 does not change significantly with temperature (e.g., displacer ring 114 may be approximately the same size as main housing volume 106 without contact due to expansion). Note that due to the small diameter of shaft 108, thermal expansion of shaft 108 can be minimal.

[0026] The displacer ring 114 can be positioned at various locations on the displacer 102. For example, the displacer ring 114 can be positioned to be on one or both sides of the displacer 102 (e.g., above or below the displacer 102). As another example, the displacer ring 114 can be positioned at a location along the displacer 102 (e.g., the displacer 102 is made from two or more pieces with one or more displacer rings 114 between them). As another example, the displacer ring 114 can be positioned at one or both ends of the displacer 102.

[0027] In an embodiment, the heat pump 100 includes an insert 116. The insert 116 may be a hollow cylinder and may fit concentrically within the sealed housing 104 (e.g., the insert forms the periphery of the main housing volume 106). As such, the displacer ring 114 may be configured to be slightly smaller than the insert 116 (e.g., the displacer ring 114 may be slightly smaller than the insert 116 rather than being slightly smaller than the main housing volume 106). The insert 116 may be made from a material with a low insert thermal conductivity coefficient and / or a low insert thermal expansion coefficient. For example, the insert 116 may be made from a material such as, but not limited to, glass, machinable glass (e.g., MACOR), ceramic, etc. (e.g., the insert 116 may be made from the same material as the displacer ring 114 or a different material from the displacer ring 114). It is noted that use of such an insert 116 may be possible because there is no pressure difference between regions within the main housing volume 106.

[0028] The insert 116, in addition to the displacer ring 114, may result in a stabilized gap 118 (e.g., the gap 118 does not experience significant material expansion and / or contraction due to the use of low-expansion material on both sides). Furthermore, the insert 116, in addition to the displacer ring 114, may result in enhanced insulation of the heat pump 100. Because the insert 116 and the displacer ring 114 may both be made from low-conductivity materials, heat flow between high-temperature and low-temperature regions of the main housing volume 106 may be reduced, preventing heat from escaping the heat pump 100 through the sealed housing 104. In this manner, the addition of the insert 116 and / or the displacer ring 114 may improve the efficiency and / or performance of the heat pump 100.

[0029] Additionally, the displacer ring 114 and insert 116 can minimize the gap 118 therebetween. Therefore, the movement of the displacer 102 and displacer ring 114 back and forth forces the gas to pass through the displacer 102 and exchange heat (e.g., the gas passes exclusively (or nearly exclusively) through the flow passages of the displacer 102 rather than around it). Additionally, 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 the thermal expansion of the displacer 102 and other components of the heat pump 100 between the cold end of the main housing volume 106 and the hot end of the main housing volume.

[0030] The materials used for the displacer ring 114 and / or insert 116 may be selected to have a thermal conductivity coefficient and / or a thermal expansion coefficient less than a threshold value. For example, the threshold value may be selected so that expansion of the displacer ring 114 and / or the insert 116 (e.g., expansion caused by temperature differences within the heat pump 100) does not result in contact with any solid surfaces (e.g., friction is prevented). Similarly, the dimensions of the displacer ring 114 and / or the insert 116 may be selected based on the thermal conductivity coefficient and / or the thermal expansion coefficient to minimize expansion and maximize insulation of the heat pump 100.

[0031] Efficient operation of the heat pump 100 can be based on gas flowing through the passages in the displacer 102, and thus through the regenerator (e.g., if the regenerator is made as a separate piece), rather than around the displacer 102. Accordingly, a precision displacer ring 114 and / or insert 116 can be used to minimize the gap 118. For example, a small gap 118 can result in substantially all of the gas in the main housing volume 106 flowing through the passages in the displacer 102, rather than around it.

[0032] In an embodiment, the heat pump 100 includes one or more secondary volumes 120 (e.g., the sealed housing 104 creates one or more secondary volumes 120 in addition to the main housing 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 main housing volume 106.

[0033] In an embodiment, 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 be operated using the pressure gain generated by heat pump 100.

[0034] In an embodiment, the heat pump 100 includes one or more bushings 124. For example, each secondary volume 120 may be defined from the main housing volume 106 by a bushing 124. The bushings 124 may form an interference fit with the housing 104 and / or the shaft 108. In this manner, gas may be prevented from migrating between the main housing volume 106 and the secondary volumes 120. The bushings 124 may further divide (e.g., separate) the sealed housing 104 into the main housing volume 106 and one or more secondary volumes 120.

[0035] In an embodiment, heat pump 100 includes a high-pressure source 126 and a low-pressure source 128. The pressures of high-pressure source 126 and low-pressure source 128 may be generated by a pressure gain generated by heat pump 100. For example, high-pressure source 126 may be coupled to a high-pressure point of heat pump 100, such as the output of heat pump 100. As another example, low-pressure source 128 may be coupled to a low-pressure point of heat pump 100, such as the input of heat pump 100. High-pressure gas may be supplied to the center of gas bearing 122 (e.g., to form a thin layer of gas to prevent contact between shaft 108 and sealed housing 104).

[0036] It is noted that while the pressure in the main housing volume 106 fluctuates between high and low pressure phases (e.g., the main housing volume 106 oscillates between high and low pressure phases), the pressure in the secondary volume 120 may remain stabilized or constant (e.g., or nearly constant). The pressure in the secondary pressure volume 120 may be kept constant by the bushing 124. The bushing 124 may be configured to significantly reduce the flow of gas between the main housing volume 106 and the secondary volume 120 (e.g., by reducing the space for gas to flow between the main housing volume 106 and the secondary volume 120 about the axis). Because the secondary volume 120 has high-pressure gas, the bushing 124 need not completely block the flow of gas between the main housing volume 106 and the secondary volume 120. Instead, the bushing 124 only needs to form a precision opening, leaving a small amount of space between the bushing 124 and the shaft 108 (e.g., to prevent friction between the shaft 108 and the bushing 124). Furthermore, it is noted that the pressure drop may be up to the amount of pressure gain in the heat pump 100, and the gas flow may be much less than the flow of the heat pump 100.

[0037] The gas bearing 122 can operate by creating a layer of gas (e.g., high-pressure gas) between two surfaces (e.g., the shaft 108 and the sealed housing 104). This layer of gas prevents the two surfaces from contacting during linear translation of the shaft 108, allowing the shaft 108 to operate in a frictionless environment (e.g., gas friction can be negligible below a certain speed threshold). Furthermore, because no lubrication is required (e.g., there is no contact), the gas bearing 122 can be suitable for use in clean environments. The bushing 124 can also result in a stabilized pressure in the secondary volume 120 (e.g., the volume in which the gas bearing 122 is located), making the gas bearing 122 suitable for operation in high-pressure environments.

[0038] High pressure source 126 and low pressure source 128 may be used to operate gas bearing 122 (e.g., gas bearing 122 may operate based on the pressure difference between the input of heat pump 100 and the output of heat pump 100). The gas flow required to operate gas bearing 122 may be much less than the gas flow generated by heat pump 100, and thus gas bearing 122 may operate while maintaining the operational capability of heat pump 100 (e.g., creating a frictionless environment). The gas used within heat pump 100 and for gas bearing 122 may be any gas. For example, the gas may be argon (Ar).

[0039] FIG. 2 is a block diagram of a system 200 in accordance with one or more embodiments of the present disclosure.

[0040] In an embodiment, the system 200 includes a heat pump 100 .

[0041] 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 requiring the operation of the heat pump 100. The heat pump 100 can be configured to provide pressurized gas to the BBP light source 202. For example, the BBP light source 202 can be configured to operate in part based on high-pressure gas. For example, the BBP light source 202 may require pressurized gas to power a laser within the BBP light source 202. Thus, the heat pump 100 can provide such pressurized gas to the BBP light source 202. Such a configuration is disclosed in U.S. Pat. No. 11,450,521, issued September 20, 2022, previously referenced herein and incorporated by reference in its entirety.

[0042] Additionally, the BBP light source 202 may be used for any application known in the art, for example, the BBP light source 202 may be used for metrology.

[0043] 3 is a flow diagram of a method 300 according to one or more embodiments of the present disclosure. Applicant notes that the embodiments and enabling techniques described herein above in the context of heat pump 100 and / or system 200 should be interpreted in an expansive manner with respect to method 300. However, it is further noted that method 300 is not limited to the mechanisms of heat pump 100 and / or system 200.

[0044] In an embodiment, method 300 includes step 302 of isolating one or more secondary volumes from a main housing volume with one or more bushings. For example, the bushings may form tight openings through the one or more secondary volumes and the main housing volume around the axis. The bushings may effectively isolate the one or more secondary volumes from the main housing volume because the secondary volumes may be under high pressure, substantially eliminating space for gas to escape between the bushings and the axis.

[0045] In an embodiment, the method 300 includes a step 304 of reciprocating a displacer coupled to a shaft to vary the pressure within the main housing volume, the heat pump having a high pressure output caused by the reciprocating displacer, and a low pressure input.

[0046] In an embodiment, the method 300 includes providing at least a first portion of the high pressure output of the heat pump to a broadband plasma light source 306. For example, a majority of the pressure gain generated by the oscillating displacer may be utilized by the broadband plasma light source.

[0047] 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 disposed within each of the one or more secondary volumes. For example, the second portion of the high-pressure output may be utilized by the gas bearings to create a film of gas. Further, gas escaping the film may be redirected to the low-pressure input of the heat pump and repressurized.

[0048] In an embodiment, method 300 includes step 310 of preventing contact between the shaft and the housing of the heat pump with one or more gas bearings. For example, a thin film of pressurized gas may 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.

[0049] In an embodiment, method 300 includes step 312 of directing gas through a displacer by one or more displacer rings and inserts within the heat pump, the gas directed through the displacer producing a high-pressure output of the heat pump, the one or more displacer rings coupled to the shaft and extending radially outward into the main housing volume, the displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient that is less than a threshold value, and an insert configured to form a periphery of the main housing volume, the insert being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient that is less than a threshold value. For example, the displacer and insert can be configured to minimize clearances within the main housing volume (e.g., clearances between the displacer ring and the insert). Minimizing such clearances can result in substantially all of the gas within the heat pump flowing through the displacer, thereby improving heat pump performance.

[0050] The subject matter described herein often illustrates various components contained within or connected to other components. It will be understood that such depicted arrangements are merely exemplary, and that many other arrangements that achieve similar functionality may actually be implemented. Conceptually, any configuration of components to achieve similar functionality is effectively “associated” such that the desired functionality is achieved. Thus, any two components combined herein to achieve specific functionality may be viewed as “associated” with each other such that the desired functionality is achieved, regardless of the mechanism or intermediate components. Similarly, any two components so associated may also be considered to be “connected” or “coupled” with each other to achieve the desired functionality, and any two components so associated may also be considered to be “couplable” with each other to achieve the desired functionality. Specific examples of “couplable” include, but are not limited to, physically interactable and / or physically interacting components, wirelessly interactable and / or wirelessly interacting components, and / or logically interactable and / or logically interacting components.

[0051] With the foregoing description, it will be apparent that the present disclosure and many of its attendant advantages will be understood and that various changes may be made in the form, construction, and arrangement of the elements without departing from the disclosed subject matter or sacrificing all of its essential advantages. The forms described are merely illustrative, and it is the intent of the appended claims to embrace and include all such modifications. It will further be understood that the invention is defined by the appended claims.

Claims

1. 1. A heat pump comprising: a sealed housing, the sealed housing being divided into a main housing volume and one or more secondary volumes; a shaft, the shaft configured to be driven to linearly reciprocate the shaft within the sealed housing; and a displacer coupled to the shaft and reciprocating within the main housing volume based on the reciprocation of the shaft, the reciprocation of the displacer creating a pressure gain between a high pressure phase and a low pressure phase; one or more displacer rings coupled to the displacer and extending radially outward into the main housing volume, the one or more displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient that is less than a threshold value; an insert configured to form a periphery of the main housing volume, the insert being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient less than the threshold value, the one or more displacer rings and the insert directing gas through the displacer; one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and the one or more secondary volumes; one or more gas bearings configured to prevent contact between the shaft and the sealed housing, the one or more gas bearings configured to operate based on the high-pressure phase and the low-pressure phase generated by pressure oscillations caused by the reciprocating motion of the displacer; A heat pump comprising:

2. 10. The heat pump of claim 1, wherein the shaft includes one or more magnets coupled to the shaft.

3. 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. 10. The heat pump of claim 1, wherein the one or more secondary volumes remain at a constant pressure.

5. 10. The heat pump of claim 1, wherein the main housing volume fluctuates between two or more pressures.

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

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

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

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

10. 1. A system comprising: a broadband plasma light source; and a heat pump configured to provide pressurized gas to the broadband plasma light source, the heat pump comprising: a sealed housing, the sealed housing being divided into a main housing volume and one or more secondary volumes; a shaft, the shaft configured to be driven to linearly reciprocate the shaft within the sealed housing; and a displacer coupled to the shaft and reciprocating within the main housing volume based on the reciprocation of the shaft, the reciprocation of the displacer creating a pressure gain between a high pressure phase and a low pressure phase; one or more displacer rings coupled to the displacer and extending radially outward into the main housing volume, the one or more displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient that is less than a threshold value; an insert configured to form a periphery of the main housing volume, the insert being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient less than the threshold value, the one or more displacer rings and the insert directing gas through the displacer; one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and the one or more secondary volumes; one or more gas bearings configured to prevent contact between the shaft and the sealed housing, the one or more gas bearings configured to operate based on the high-pressure phase and the low-pressure phase generated by pressure oscillations caused by the reciprocating motion of the displacer; Including heat pumps A system comprising:

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

12. 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. 11. A heat pump according to claim 10, wherein the one or more secondary volumes remain at a constant pressure.

14. 11. The heat pump of claim 10, wherein the main housing volume fluctuates between two or more pressures.

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

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

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

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

19. 1. A method of heat pump operation comprising: isolating one or more secondary volumes from the main housing volume by one or more bushings; reciprocating a displacer coupled to a shaft to vary the pressure within the main housing volume, the heat pump having high pressure and low pressure phases caused by the reciprocating 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 disposed in 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; directing gas through the displacer with one or more displacer rings and inserts within the heat pump, the gas directed through the displacer producing the high pressure phase of the heat pump, the one or more displacer rings coupled to the shaft and extending radially outward into the main housing volume, the displacer rings being made from a displacer ring material selected to have at least one of a displacer ring thermal conductivity coefficient or a displacer ring thermal expansion coefficient less than a threshold value, the insert configured to form a periphery of the main housing volume, the insert being made from an insert material selected to have at least one of an insert thermal conductivity coefficient or an insert thermal expansion coefficient less than the threshold value; A method comprising:

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