A Thermally-Driven Heat Pump Having a Heat Exchanger Located Between Displacers
A thermally driven heat pump is disclosed in which at least most of the warm heat exchanger is disposed within the cylinder between the hot and cold displacers. Such an arrangement is not suitable for a prior art heat pump in which movement of the displacers is based on a crank because it would lead to too much dead volume in the system. However, with mechatronically-controlled displacers in which the displacers are independently controlled, the displacers can reciprocate up to the heat exchanger. Such a configuration reduces dead volume compared to prior art Vuilleumier heat pumps in which the warm exchanger occupies a portion of an annular space between the cylinder in which the displacers move.
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The present disclosure relates to arrangement of a heat exchanger in a thermally-driven heat pump.
BACKGROUND ART
A prior art Vuilleumier heat pump 5 is shown in
A thermally-driven heat pump in which the displacers are mechatronically actuated is disclosed in commonly-assigned patent application PCT/US13/36101 filed 11 Apr. 2013. The displacers are independently actuated such that one displacer may be held stationary while the other moves. In the heat pump disclosed in PCT/US13/36101, neither displacer reciprocates into the stroke of the other displacer, i.e., no overlap over in space of the two displacers. This is in contrast with the movement shown in
To exploit an opportunity provided by independent displacer operation over prior Vuilleumier heat pumps associated with crank movement, a heat pump is disclosed that includes a housing having: a hot cap, a cold cap, a hot cylinder portion proximate the hot cap, and a cold cylinder portion proximate the cold cap. The heat pump includes a cold displacer disposed within the cold cylinder portion, a hot displacer disposed within the hot cylinder portion, a post coupled to the cold cap and extending toward the hot cap along a centerline of the cold cylinder portion, and a substantially disk-shaped warm heat exchanger. The warm heat exchanger is located between the hot and cold displacers. An opening is defined in the warm heat exchanger to accommodate the post. A diameter of the opening in the warm heat exchanger is less than a diameter of the cold displacer. The warm heat exchanger is housed within a warm heat exchanger cylinder portion. In some embodiments, the hot cylinder portion, the cold cylinder portion, and the warm heat exchanger cylinder portion are of the same diameter.
The warm heat exchanger has an inlet that pierces the warm heat exchanger cylinder portion and an outlet that pierces the warm heat exchanger cylinder portion.
In one embodiment, the warm heat exchanger comprises at least one tube wrapped in a spiral with adjacent turns of the spiral separated by at most a predetermined distance. A working fluid within the hot and cold cylinder portions pass through the separations between adjacent turns of the spiral in response to movement of the displacers. Alternatively, the warm heat exchanger comprises a tube-and-shell heat exchanger with a working fluid within the hot and cold cylinder portions passing between the tubes in response to movement of the displacers. Alternatively, any suitable heat exchanger configuration may be provided for the warm heat exchanger.
The heat pump may further include a hot heat exchanger located proximate the hot cap and fluidly coupled to a chamber within the hot cylinder portion, a hot regenerator having one end fluidly coupled to the hot heat exchanger and one end fluidly coupled to a chamber within the cold cylinder portion, a cold heat exchanger fluidly coupled to a cold chamber within the cold cylinder portion, and a cold regenerator having one end fluidly coupled to the cold heat exchanger and one end fluidly coupled to a hot warm chamber within the hot cylinder portion.
The hot displacer reciprocation is limited by the hot cap and the warm heat exchanger. The cold displacer reciprocation is limited by the cold cap and the warm heat exchanger.
The heat pump may further include a hot heat exchanger proximate the hot cap and fluidly coupled to a hot chamber within the hot cylinder portion; a cold heat exchanger fluidly coupled to a cold chamber within the cold cylinder portion; an annular-shaped hot regenerator arranged outside the hot cylinder portion; and an annular-shaped cold regenerator arranged outside the cold cylinder portion. A first end of the hot regenerator is fluidly coupled to the hot heat exchanger and a second end of the hot regenerator is fluidly coupled to a cold warm chamber within the cold cylinder portion. A first end of the cold regenerator is fluidly coupled to the cold heat exchanger and a second end of the cold regenerator is fluidly coupled to a hot warm chamber within the hot cylinder portion.
The hot chamber is delimited by the hot cap, the hot cylinder portion, and the hot displacer. The cold chamber is delimited by the cold cap, the cold cylinder portion, and the cold displacer. The hot warm chamber is delimited by the warm heat exchanger, the hot cylinder portion, and the hot displacer. The cold warm chamber is delimited by the warm heat exchanger, the cold cylinder portion, and the cold displacer.
Also disclosed is a heat pump that includes a heat pump housing with: a hot cap, a cold cap, a hot cylinder portion near the hot cap, and a cold cylinder portion near the cold cap. The heat pump has a cold displacer disposed within the cold cylinder portion, a hot displacer disposed within the hot cylinder portion, and a substantially disk-shaped warm heat exchanger between the hot cylinder portion and the cold cylinder portion. The cold displacer reciprocates between the warm heat exchanger and the cold cap; and the hot displacer reciprocates between the warm heat exchanger and the hot cap.
The heat pump has a post coupled to the cold cap and extending toward the hot cap along a centerline of the cold cylinder portion. An opening is defined in the warm heat exchanger to accommodate the post. A diameter of the opening in the warm heat exchanger is less than a diameter of the cold displacer.
The heat pump further includes: a hot heat exchanger located proximate the hot cap and fluidly coupled to the hot cylinder portion, a hot regenerator having one end fluidly coupled to the hot heat exchanger and one end fluidly coupled to the cold cylinder portion, a cold heat exchanger fluidly coupled to the cold cylinder portion, and a cold regenerator having one end fluidly coupled to the cold heat exchanger and one end fluidly coupled to the hot cylinder portion.
The heat pump may include an annularly-shaped hot regenerator arranged outside the hot cylinder portion, an annularly-shaped cold regenerator arranged outside the cold cylinder portion, a hot chamber delimited by the hot cylinder portion, the hot displacer, and the hot cap, a hot warm chamber delimited by the hot cylinder portion, the hot displacer, and the warm heat exchanger, a cold warm chamber delimited by the cold cylinder portion, the cold displacer, and the warm heat exchanger, a cold chamber delimited by the cold cylinder portion, the cold displacer, and the cold cap, a hot heat exchanger fluidly coupled to the hot chamber and to the hot regenerator, and a cold heat exchanger fluidly coupled to the cold chamber and to the cold regenerator. The hot regenerator is fluidly coupled to the hot heat exchanger and the cold warm chamber. The cold regenerator is fluidly coupled to the cold heat exchanger and the hot warm chamber.
In some embodiments, the heat pump also has a hot heat exchanger disposed in the hot cap and a cold heat exchanger annularly arranged around the cold cylinder portion.
According to an embodiment of the present disclosure, a heat pump has a housing having a hot cap on one end of the housing and a cold cap on the other end of the housing, a cylinder within the housing, a substantially disk-shaped warm heat exchanger disposed within the housing and roughly centrally located between the hot cap and the cold cap, a hot displacer disposed in a portion of the cylinder between the warm heat exchanger and the hot cap, and a cold displacer disposed in a portion of the cylinder between the warm heat exchanger and the cold cap. The cylinder has a hot cylinder portion and a cold cylinder portion. A hot chamber is delimited by the hot cap, the hot cylinder portion, and the hot displacer. A cold chamber is delimited by the cold cap, the cold cylinder portion, and the cold displacer. A hot warm chamber is delimited by the warm heat exchanger, the hot cylinder portion, and the hot displacer. A cold warm chamber is delimited by the warm heat exchanger, the cold cylinder portion, and the cold displacer. The heat pump includes: a hot heat exchanger proximate fluidly coupled to the hot chamber, a cold heat exchanger fluidly coupled to the cold chamber, a hot regenerator, and a cold regenerator. A first end of the hot regenerator is fluidly coupled to the hot heat exchanger. A second end of the hot regenerator is fluidly coupled to a cold warm chamber. A first end of the cold regenerator is fluidly coupled to the cold heat exchanger. A second end of the cold regenerator is fluidly coupled to a hot warm chamber.
In some embodiments, the hot regenerator is annularly arranged outside the cylinder near the hot cap and the cold regenerator is annularly arranged outside the cylinder near the cold cap.
In heat pumps in which the displacers are driven by a crank arrangement, a warm heat exchanger cannot be placed within the cylinder unless the displacers were to be separated so that they do not overlap the same space. Such an arrangement would yield too much dead volume and would seriously impair thermal efficiency. The mechatronically-driven heat pump allows for the warm heat exchanger to be located within the cylinder without such a large dead volume. The gases in the cylinder readily flow over the warm heat exchanger compared with the prior-art configuration where the warm heat exchanger was in an annular volume outside the cylinder.
An advantage of the disclosed configuration is that the warm heat exchanger is more easily manufactured compared to a heat exchanger that resides in an annular volume. Another advantage of embodiments in which recuperators are disposed in the passages is that the recuperators are more easily formed in a circular or other simple cross-sectional shape compared with an annulus. Yet another advantage in some alternatives is a reduction in dead volume by obviating passages to and from the warm heat exchanger.
Vuilleumier heat pump 5 in
As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the Figures may be combined with features illustrated in one or more other Figures to produce alternative embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. Those of ordinary skill in the art may recognize similar applications or implementations whether or not explicitly described or illustrated.
A thermally-driven heat pump 300 has a housing 302 which has a hot cap 304 on each end is shown in
Continuing to refer to
One example of motion of the displacers of
In
In the embodiment in
Movement of the displacers of
In
In
In
In
In
In
In
In
The description of the gas movement implies that the gases make a complete loop. However, the gases move in the path described, but gases starting on one side of the displacer do not make the complete path to the other side of the displacer, but instead make travel through part of the loop.
An alternative heat pump 100 configuration is illustrated in
A view down the cylinder of the two warm heat exchanger alternatives previously illustrated is shown in
A shell-and-tube heat exchanger 160 similar to that illustrated in
In the embodiment of heat pump 200 in
While the best mode has been described in detail with respect to particular embodiments, those familiar with the art will recognize various alternative designs and embodiments within the scope of the following claims. While various embodiments may have been described as providing advantages or being preferred over other embodiments with respect to one or more desired characteristics, as one skilled in the art is aware, one or more characteristics may be compromised to achieve desired system attributes, which depend on the specific application and implementation. These attributes include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. The embodiments described herein that are characterized as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
Claims
1. A heat pump, comprising:
- a heat pump housing having: a hot cap, a cold cap, a hot cylinder portion proximate the hot cap, and a cold cylinder portion proximate the cold cap;
- a cold displacer disposed within the cold cylinder portion;
- a hot displacer disposed within the hot cylinder portion; and
- a substantially disk-shaped warm heat exchanger between the hot cylinder portion and the cold cylinder portion wherein: the cold displacer reciprocates between the warm heat exchanger and the cold cap; and the hot displacer reciprocates between the warm heat exchanger and the hot cap.
2. The heat pump of claim 1, further comprising:
- a post coupled to the cold cap and extending toward the hot cap along a centerline of the cold cylinder portion wherein:
- an opening is defined in the warm heat exchanger to accommodate the post; and
- a diameter of the opening in the warm heat exchanger is less than a diameter of the cold displacer.
3. The heat pump of claim 1, further comprising:
- a hot heat exchanger located proximate the hot cap and fluidly coupled to the hot cylinder portion; and
- a hot regenerator having one end fluidly coupled to the hot heat exchanger and one end fluidly coupled to the cold cylinder portion.
4. The heat pump of claim 1, further comprising:
- a cold heat exchanger fluidly coupled to the cold cylinder portion; and
- a cold regenerator having one end fluidly coupled to the cold heat exchanger and one end fluidly coupled to the hot cylinder portion.
5. The heat pump of claim 1, further comprising:
- a hot regenerator arranged outside the hot cylinder portion; and
- a cold regenerator arranged outside the cold cylinder portion.
6. The heat pump of claim 5, further comprising:
- a hot chamber delimited by the hot cylinder portion, the hot displacer, and the hot cap;
- a hot warm chamber delimited by the hot cylinder portion, the hot displacer, and the warm heat exchanger;
- a cold warm chamber delimited by the cold cylinder portion, the cold displacer, and the warm heat exchanger;
- a cold chamber delimited by the cold cylinder portion, the cold displacer, and the cold cap; and
- a hot heat exchanger fluidly coupled to the hot chamber and to the hot regenerator;
- a cold heat exchanger fluidly coupled to the cold chamber and to the cold regenerator, wherein: the hot regenerator is fluidly coupled to the hot heat exchanger and the cold warm chamber; and the cold regenerator is fluidly coupled to the cold heat exchanger and the hot warm chamber.
7. The heat pump of claim 1, further comprising:
- a hot heat exchanger disposed in the hot cap; and
- a cold heat exchanger annularly arranged around the cold cylinder portion.
8. The heat pump of claim 1 wherein:
- the warm heat exchanger comprises at least one tube wrapped in a spiral;
- adjacent turns of the spiral are separated by at most a predetermined distance; and
- a working fluid within the hot and cold cylinder portions pass through the separations between adjacent turns of the spiral in response to movement of the displacers.
9. The heat pump of claim 1, further comprising:
- a hot heat exchanger proximate the hot cap and fluidly coupled to a hot chamber within the hot cylinder portion;
- a cold heat exchanger fluidly coupled to a cold chamber within the cold cylinder portion;
- an annular-shaped hot regenerator arranged outside the hot cylinder portion; and
- an annular-shaped cold regenerator arranged outside the cold cylinder portion wherein:
- a first end of the hot regenerator is fluidly coupled to the hot heat exchanger;
- a second end of the hot regenerator is fluidly coupled to a cold warm chamber within the cold cylinder portion;
- a first end of the cold regenerator is fluidly coupled to the cold heat exchanger; and
- a second end of the cold regenerator is fluidly coupled to a hot warm chamber within the hot cylinder portion.
10. The heat pump of claim 1 wherein the warm heat exchanger is housed within a warm heat exchanger cylinder portion; and the hot cylinder portion, the cold cylinder portion, and the warm heat exchanger cylinder portion are of the same diameter.
11. The heat pump of claim 1 wherein the warm heat exchanger is housed within a warm heat exchanger portion; and the warm heat exchanger has an inlet that pierces the warm heat exchanger cylinder portion and an outlet that pierces the warm heat exchanger cylinder portion.
12. A heat pump, comprising:
- a housing having a hot cap on one end of the housing and a cold cap on the other end of the housing;
- a cylinder within the housing;
- a substantially disk-shaped warm heat exchanger disposed within the housing and roughly centrally located between the hot cap and the cold cap;
- a hot displacer disposed in a portion of the cylinder between the warm heat exchanger and the hot cap; and
- a cold displacer disposed in a portion of the cylinder between the warm heat exchanger and the cold cap.
13. The heat pump of claim 12 wherein the cylinder has a hot cylinder portion and a cold cylinder portion, the heat pump further comprising:
- a hot chamber delimited by the hot cap, the hot cylinder portion, and the hot displacer;
- a cold chamber delimited by the cold cap, the cold cylinder portion, and the cold displacer;
- a hot warm chamber delimited by the warm heat exchanger, the hot cylinder portion, and the hot displacer;
- a cold warm chamber delimited by the warm heat exchanger, the cold cylinder portion, and the cold displacer;
- a hot heat exchanger proximate fluidly coupled to the hot chamber;
- a cold heat exchanger fluidly coupled to the cold chamber;
- a hot regenerator; and
- a cold regenerator, wherein:
- a first end of the hot regenerator is fluidly coupled to the hot heat exchanger;
- a second end of the hot regenerator is fluidly coupled to a cold warm chamber;
- a first end of the cold regenerator is fluidly coupled to the cold heat exchanger; and
- a second end of the cold regenerator is fluidly coupled to a hot warm chamber.
14. The heat pump of claim 13 wherein:
- the hot regenerator is annularly arranged outside the cylinder near the hot cap; and
- the cold regenerator is annularly arranged outside the cylinder near the cold cap.
15. A heat pump, comprising:
- a heat pump housing having: a hot cap, a cold cap, a hot cylinder portion proximate the hot cap, and a cold cylinder portion proximate the cold cap;
- a cold displacer disposed within the cold cylinder portion;
- a hot displacer disposed within the hot cylinder portion; and
- a substantially disk-shaped warm heat exchanger wherein:
- the warm heat exchanger is located between the hot and cold displacers.
16. The heat pump of claim 1.5 wherein:
- the warm heat exchanger is housed within a warm heat exchanger cylinder portion; and
- the hot cylinder portion, the cold cylinder portion, and the warm heat exchanger cylinder portion are of the same diameter.
17. The heat pump of claim 15 wherein the warm heat exchanger has an inlet that pierces the warm heat exchanger cylinder portion and an outlet that pierces the warm heat exchanger cylinder portion.
18. The heat pump of claim 15 wherein:
- the warm heat exchanger comprises at least one tube wrapped in a spiral;
- adjacent turns of the spiral are separated by at most a predetermined distance; and
- a working fluid within the hot and cold cylinder portions pass through the separations between adjacent turns of the spiral in response to movement of the displacers.
19. The heat pump of claim 15, further comprising:
- a hot heat exchanger located proximate the hot cap and fluidly coupled to a chamber within the hot cylinder portion;
- a hot regenerator having one end fluidly coupled to the hot heat exchanger and one end fluidly coupled to a chamber within the cold cylinder portion.
20. The heat pump of claim 15, further comprising:
- a hot heat exchanger proximate the hot cap and fluidly coupled to a hot chamber within the hot cylinder portion;
- a cold heat exchanger fluidly coupled to a cold chamber within the cold cylinder portion;
- an annular-shaped hot regenerator arranged outside the hot cylinder portion; and
- an annular-shaped cold regenerator arranged outside the cold cylinder portion wherein:
- a first end of the hot regenerator is fluidly coupled to the hot heat exchanger;
- a second end of the hot regenerator is fluidly coupled to a cold warm chamber within the cold cylinder portion;
- a first end of the cold regenerator is fluidly coupled to the cold heat exchanger; and
- a second end of the cold regenerator is fluidly coupled to a hot warm chamber within the hot cylinder portion.
Type: Application
Filed: Feb 21, 2015
Publication Date: Jun 15, 2017
Applicant: ThermoLift, Inc. (Stony Brook, NY)
Inventor: Peter Hofbauer (West Bloomfield, MI)
Application Number: 15/118,332