Solid-state refrigeration driver based on unloading mechanical work recovery and refrigeration equipment

Abstract

The invention relates to a rotary solid-state refrigeration driver based on unloading mechanical work recovery and solid-state refrigeration equipment. The rotary solid-state refrigeration driver comprises a rotary motor, a main transmission shaft, N eccentric transmission mechanisms and N pistons, wherein the main transmission shaft is driven by the rotary motor to rotate; the N eccentric transmission mechanisms are mounted at different axial positions of the main transmission shaft; the N pistons are respectively driven by the N eccentric transmission mechanisms to do reciprocating motion; the N eccentric transmission mechanisms are used for driving the N pistons to reciprocate, the N elastic clamping materials are periodically loaded and unloaded through the reciprocating motion of the N pistons, and the N eccentric transmission mechanisms have different phase angles, so that the unloading time periods of the N elastic clamping materials are different; each elastic clamping material releases self mechanical work to provide thrust for rotation of the main transmission shaft in the unloading process; n is an integer greater than 1. According to the rotary type solid-state refrigeration driver, elastic mechanical energy stored in the unloading process of an elastic clamping material is utilized, recycling of unloading mechanical work is achieved, and then the energy utilization rate of elastic clamping solid-state refrigeration is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state refrigeration, and specifically relates to a rotary solid-state refrigeration driver for realizing unloading mechanical work recovery of ejected stuck materials under rotational motion, and a solid-state refrigeration device including the rotary solid-state refrigeration driver. Background Art

[0002] Space cooling is an important guarantee for people to maintain a high quality of life in modern times, including the use of air conditioners to reduce indoor temperatures or refrigerators to preserve food in a specific space at low temperatures. However, under the challenge of future sustainable development, today's gas compression-based refrigerators have exposed many problems: First, there are many problems with the refrigerants used in gas compression refrigerators. Looking around the world, refrigerants in gas compression refrigerators (such as chlorine and bromine refrigerants) are manufactured and released into the environment in large quantities. Although this type of refrigerant itself is not toxic to organisms, its evaporation in the atmosphere will cause a sharp drop in the ozone content in the atmosphere, and the earth's atmosphere has been irreversibly damaged by the chemical action of this type of refrigerant. The earth's surface is directly exposed to a large amount of ultraviolet rays under the ozone hole, which not only increases the overall temperature of the earth and induces more extreme weather, but also makes it very easy for organisms to have adverse effects on their bodies (such as skin cancer) under excessive ultraviolet radiation. Although new refrigerants have been developed through technological iteration (such as fluorine-containing and ammonia refrigerants), and their harm to the environment has been reduced, such refrigerants have the disadvantages of being flammable and explosive, and there are great safety risks when used by the public. Secondly, the energy conversion rate of refrigeration through gas compression is low, and a large part of the electricity produced by power plants is not well converted in the refrigeration process, resulting in a great waste of public resources. The indicator for evaluating the energy efficiency performance of refrigerators today is the energy efficiency ratio (based on the ratio of output refrigeration power to input electrical power). For example, the energy efficiency ratio of air conditioners generally circulated in the market is about 2.3 to 3.5. If air conditioners with a higher energy efficiency ratio (for example, greater than 6) can be used for refrigeration, then only half of the original electrical energy support is needed to obtain the same refrigeration effect. However, due to the low entropy change of the gas-liquid two-phase phase transition, the improvement of the energy efficiency ratio of such refrigerators has encountered its own technical bottleneck. Therefore, the proposal and development of a new generation of environmentally friendly and efficient refrigeration technology has become an important prerequisite for achieving sustainable development of mankind in the future.

[0003] The elastocaloric solid-state refrigeration technology is a new refrigeration technology that utilizes the first-order phase change of solid materials. This technology mechanically deforms the material to induce a phase change in the material, resulting in the release and absorption of latent heat, thereby reducing the temperature of the target object. The elastocaloric refrigeration cycle generally includes four processes: loading, holding and heat exchange, unloading, and holding and heat exchange. Since this new technology was proposed by British scientists in 2004, it has received extensive attention from researchers around the world. The most important reason is its high energy conversion efficiency, safety during use, and no additional emissions to the environment. In the future refrigeration technology development guidelines released by the US Department of Energy in 2014, the elastocaloric solid-state refrigeration technology using elastocaloric materials received the highest score and was evaluated as one of the refrigeration technologies most likely to replace existing gas compression refrigeration. Elastocaloric materials refer to solid materials with elastocaloric (thermal) effects. The elastocaloric effect is one of the thermal effects of solid materials. It is the release or absorption of heat generated by applying an external stress field, causing the material to undergo strain. Elastocaloric materials based on the elastocaloric effect of phase change have the characteristic of high entropy change, which can greatly improve the energy conversion efficiency. There are many materials with elastocaloric properties, including shape memory alloys, natural rubber, synthetic polymers, plastic crystals, etc. Among them, shape memory alloys (such as nickel-titanium alloys, copper-aluminum-manganese alloys, nickel-manganese-copper-cobalt alloys, nickel-iron-gallium alloys, etc.) are widely used in elastocaloric solid-state refrigeration technology due to their extremely high phase change entropy values and material energy efficiency ratios. For example, the widely used nickel-titanium alloy can produce an entropy change of 0.32 J / cm 3 K under adiabatic phase change, far higher than the entropy change (0.035 J / cm 3 K) of the most widely used gas compression refrigerant R-32 (hydrofluorocarbon) nowadays. Due to its high phase change entropy value, the energy efficiency ratio of shape memory alloys can reach more than 30. In recent years, many research results have been obtained in the development of prototypes in the research of elastocaloric solid-state refrigeration. Especially in terms of refrigeration effect, a large temperature difference of 50 K and a specific refrigeration power of 6 W / g have been achieved. However, the actual working energy efficiency ratio of the prototype (about 1) is far less than the material energy efficiency ratio. The problems of energy utilization and conversion seriously hinder the further development of this technology in commercialization.

[0004] One of the main reasons for the low energy efficiency ratio of the elastocaloric solid-state refrigeration prototype system is that the unloading mechanical work of the elastocaloric material from deformation to restoration of its original state is not effectively utilized. When the material is in a deformed state, it is a state of energy storage. If the external constraints are removed, the elastocaloric material can release the mechanical energy stored inside. If this part of the mechanical work can be utilized, the power requirement for the external driver can be greatly reduced, thus achieving a higher system energy efficiency ratio. The current elastocaloric refrigeration prototypes generally adopt a structure with linear drive (such as hydraulic push rods, linear push rods, etc.). For example, a research team from the University of Michigan designed and developed a refrigeration prototype with a hydraulic push rod as the driver and the compression of a nickel-titanium alloy tube as the principle. Using water as the heat exchange medium, a maximum temperature difference of 20K was obtained, and the results were published in the international academic journal Science; a research team from the University of Ljubljana also used a hydraulic push rod as the driver of the prototype, and a sleeve structure was used to compress the nickel-titanium alloy tube to achieve the elastocaloric effect, and the results were published in the international academic journal Nature Energy; Chinese Patent CN201810660524.1 (Publication No. CN108954901A, Publication Date: December 7, 2018) discloses an elastocaloric refrigeration device using the compression deformation of a nickel-titanium alloy tube. Water is used as the heat transfer medium. Through the axial reciprocating motion of a linear motor, the nickel-titanium alloy tube is compressed to cause compressive deformation, and an external water pump is used to drive the water circulation to conduct convective heat transfer on the nickel-titanium alloy tube. Although linear drive is conceptually feasible, whether using a linear motor or a hydraulic device, when there is no external energy supply, due to the limitations of the mechanical structure, the ram will be locked. The driver still needs to input electrical energy to retract the ram during the actual unloading process, which will increase the power consumption of the driver. If the ram is not a movable part, the released mechanical energy during the unloading of the material cannot be transferred to the next stage and drive the next loading. In contrast, mechanical energy can be easily transferred through rotation. During the unloading process, the linear motion of the material can be used to push the rotation of the shaft in the tangential direction to maintain the rotation of the shaft; and the rotating shaft can continuously drive the compression of the next stage. In addition, due to fewer mechanisms and components, the rotary drive system has a higher mechanical efficiency (the ratio of the electrical input power to the mechanical output power). An efficient rotary drive system has a mechanical efficiency of 90%, which can greatly reduce the power waste during the energy conversion itself. Although the rotary drive system has great application potential in elastocaloric refrigeration, so far, no clear technical route and structural design of the drive system have been provided in the existing literature and patents. Summary of the Invention

[0005] To solve at least one of the above problems, the present disclosure provides a rotary solid-state refrigeration driver based on the recovery of unloading mechanical work and a solid-state refrigeration device including the rotary solid-state refrigeration driver.

[0006] According to a first aspect of the present disclosure, there is provided a rotary solid-state refrigeration driver based on the recovery of unloading mechanical work. The rotary solid-state refrigeration driver includes: a rotary motor, a main transmission shaft driven by the rotary motor to rotate, N eccentric transmission mechanisms installed at different axial positions of the main transmission shaft and all driven by the main transmission shaft, N pistons respectively driven by the N eccentric transmission mechanisms to perform reciprocating motions, and N elastocaloric materials respectively periodically loaded-unloaded through the reciprocating motions of the N pistons, where N is an integer greater than 1; the N eccentric transmission mechanisms have different phase angles relative to the main transmission shaft, such that the time periods during which the N elastocaloric materials are unloaded are different; and each elastocaloric material provides a thrust for the rotation of the main transmission shaft by releasing its own mechanical work during the unloading process.

[0007] Optionally, along the axial direction of the main transmission shaft, the difference in the phase angles between any two adjacent eccentric transmission mechanisms among the N eccentric transmission mechanisms is 360 / N degrees.

[0008] Optionally, the eccentric transmission mechanism cooperates with the main transmission shaft and the piston to form an eccentric connecting rod mechanism, an eccentric cam mechanism, an eccentric bearing mechanism or a crank connecting rod mechanism.

[0009] Optionally, at each of the different axial positions of the main transmission shaft: the cross-section of the main transmission shaft is circular and the center of the circle does not coincide with the rotation axis of the main transmission shaft; and the eccentric transmission mechanism includes a connecting rod portion and a pin, one end of the connecting rod portion away from the piston includes a circular ring portion, the circular ring portion is sleeved on the outer peripheral surface of the main transmission shaft and can slide circumferentially relative to the outer peripheral surface of the main transmission shaft, and the other end of the connecting rod portion is hinged to one end of the piston away from the elastocaloric material through the pin.

[0010] Optionally, the connecting rod portion includes an upper connecting rod portion and a lower connecting rod portion, the circular ring portion is formed by the lower part of the upper connecting rod portion and the lower connecting rod portion, and the upper connecting rod portion and the lower connecting rod portion are connected together by screws.

[0011] Optionally, the rotary solid-state refrigeration driver further includes: a linear bearing sleeved outside the corresponding piston for defining the direction of the reciprocating motion of the piston and reducing radial friction.

[0012] Optionally, the rotary solid-state refrigeration driver further includes: a first external frame supporting the corresponding piston and elastocaloric material, and both ends of each elastocaloric material are fixed between the corresponding piston and the first external frame in a manner of direct contact, threaded connection, welding or bonding.

[0013] Optionally, the rotary solid-state refrigeration driver further includes: an upper housing part and a lower housing part, which are respectively used to carry the piston and the main transmission shaft.

[0014] Optionally, the rotary motor is selected from: servo motor, stepper motor, torque motor, switched reluctance motor, brushless DC motor.

[0015] Optionally, the rotary solid-state refrigeration driver further includes a speed reducer, and the speed reducer is used to increase the torque of the rotary motor.

[0016] Optionally, the rotary motor drives the speed reducer and then drives the main transmission shaft to rotate.

[0017] Optionally, the rotary solid-state refrigeration driver further includes a second outer frame for fixing the speed reducer and the eccentric transmission mechanism.

[0018] Optionally, the geometric shape of the elastic card material is selected from: cylindrical, cubic, cuboid, circular tube, rectangular tube.

[0019] Optionally, the elastic card material is selected from: shape memory alloy, natural rubber, synthetic polymer, plastic crystal.

[0020] Optionally, the elastic card material is selected from: nickel-titanium alloy, copper-aluminum-manganese alloy, nickel-manganese-titanium alloy, nickel-titanium-cobalt alloy, nickel-titanium-copper-cobalt alloy, nickel-iron-gallium alloy.

[0021] Optionally, the deformation mode of the loading-unloading process of the elastic card material is uniaxial linear deformation, and the uniaxial linear deformation includes linear compression and linear tension.

[0022] According to a second aspect of the present disclosure, there is provided a solid-state refrigeration device, which includes a rotary solid-state refrigeration driver based on recovery of unloading mechanical work according to the first aspect of the present disclosure, and further includes a heat exchange structure, and the heat exchange structure is used to exchange heat with the elastic card material to transfer the heat and cold generated by the elastic card material.

[0023] Compared with the prior art, the rotary solid-state refrigeration driver and the solid-state refrigeration device of the present disclosure have the following advantages:

[0024] 1. Adopting a rotary loading method: Compared with the existing hydraulic or linear motor drive, the number of mechanical transmission devices is greatly reduced, thereby reducing the loss of mechanical energy and electrical energy.

[0025] 2. Realizing the recovery of unloading mechanical work: The present disclosure adopts a multi-cylinder structure including a plurality of eccentric transmission mechanisms and a plurality of pistons, and the unloading mechanical work of one of the elastic card materials can be recovered and reused to load another elastic card material, realizing the recovery and utilization of energy and reducing energy consumption.

[0026] 3. Large and adjustable temperature drop of solid refrigerant: By adjusting the eccentricity distance, the maximum temperature drop of the snap spring material can reach 30 degrees in a single time.

[0027] 4. Continuous output of cooling capacity: Compared with traditional snap spring materials that need to wait for heat dissipation before using the cooling capacity, in this disclosure, due to the multi-cylinder design, the intermittent refrigeration of multiple snap spring materials can be superimposed into continuous refrigeration, greatly improving the efficiency and refrigeration power.

[0028] 5. Miniaturization and commercialization: Compared with existing hydraulic or linear motor drives, the overall weight and volume are greatly reduced, and the safety and portability are improved.

[0029] 6. High-frequency operation: The highest operating frequency can reach 5 Hz, improving the refrigeration power. Description of the Drawings

[0030] Figure 1 is a schematic diagram showing the principle of unloading mechanical work recovery according to the present disclosure;

[0031] Figure 2 is a perspective view showing a part of a rotary solid-state refrigeration driver according to an exemplary embodiment of the present disclosure;

[0032] Figure 3 is a front view showing the structure and installation process of a part of a rotary solid-state refrigeration driver according to an exemplary embodiment of the present disclosure;

[0033] Figure 4 is a front view showing a part of a rotary solid-state refrigeration driver according to an exemplary embodiment of the present disclosure;

[0034] Figure 5 is a perspective view showing a part of a rotary solid-state refrigeration driver according to an exemplary embodiment of the present disclosure;

[0035] Figure 6 is a graph showing the change of torque on the main transmission shaft with respect to the rotation angle according to an exemplary embodiment of the present disclosure and a comparative example.

[0036] Description of Reference Numerals:

[0037] 1 piston 2 main transmission shaft 3 connecting rod part

[0038] 3a upper part of the connecting rod 3b lower part of the connecting rod 4 pin

[0039] 5a upper part of the housing 5b lower part of the housing 6 linear bearing

[0040] 7a second external frame 7b first external frame 8 speed reducer

[0041] 9 Rotary motor 10 Elastic card material 0 Axis of rotation Detailed implementation mode

[0042] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the forms of unloading mechanical work recovery and the structure of the unloading work recovery driver applying its principle provided by the present disclosure will be described in detail below with reference to the accompanying drawings.

[0043] The terms used in the present disclosure are only for describing specific embodiments and are not intended to limit the present disclosure. As used in the present disclosure, the term "and / or" includes any and all combinations of one or more related listed items. As used in the present disclosure, the singular forms "a" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. As used in the present disclosure, the terms "comprising", "made of", specify the presence of the stated features, wholes, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their groups.

[0044] In the description of the present disclosure, it should be noted that the orientation or positional relationship indicated by the terms "top", "bottom", "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product is normally placed during use. It is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present disclosure.

[0045] Unless otherwise defined, the meanings of all terms (including technical and scientific terms) used in the present disclosure are the same as those commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in common dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and the context of the present disclosure, and will not be interpreted as having an idealized or overly formal meaning unless the present disclosure clearly so defines.

[0046] As Figure 1As shown, it shows the principle of offloading mechanical work recovery according to the present disclosure. Based on the principle of object deformation, when an object deforms (tension, compression, torsion, bending, etc.), it stores elastic deformation mechanical energy by itself. As the deformation ends, the object outputs the stored mechanical energy to the outside world. The same is true for the elastocaloric material. Generally speaking, the material applied to elastocaloric refrigeration has superelasticity (or pseudoelasticity), that is, it can undergo large elastic deformation and can return to its original state without residual strain. Based on this characteristic, the present disclosure adopts an eccentric drive mechanism to drive the elastocaloric material to deform, and uses the elastic deformation mechanical energy stored by the elastocaloric material itself to drive the transmission shaft of the eccentric mechanism to rotate in the reverse direction; at the same time, the elastocaloric material itself will undergo a phase change when subjected to external deformation, releasing or absorbing heat, so that refrigeration work can be carried out.

[0047] For the sake of simplicity of explanation, Figure 1 an eccentric wheel is taken as an example of the eccentric drive mechanism. When the distal part of the eccentric wheel rotates to below the elastocaloric material, the distal part presses against the elastocaloric material, causing the elastocaloric material to release heat while undergoing compressive deformation; as the eccentric wheel continues to rotate, after passing over the highest point of the distal part, the elastocaloric material enters the unloading process, releasing the elastic deformation mechanical energy and absorbing the heat of the surrounding environment. The mechanical energy released by the elastocaloric material can be transmitted to the eccentric wheel, thereby helping to drive the eccentric wheel to rotate. The inventor also found that since the transmission shaft needs to be connected to the motor, the gear structure of the motor itself has self-locking and cannot instantaneously change speed and rotate (that is, it cannot maintain rotation by inertia). If only a single-cylinder design is adopted, that is, there is only one elastocaloric material in the device, the mechanical work of unloading instantaneously transmitted to the transmission shaft cannot be stored and transmitted to the same elastocaloric material for loading in the next time period. Therefore, the present disclosure adopts a multi-cylinder mechanism design (at least two cylinders or more). Through the phase angle design of the eccentric position, that is, when one material is loaded, the other is unloaded, the torque on the transmission shaft will be reduced due to the simultaneous action of the two materials. That is, driving two materials simultaneously will require less torque than the sum of the torques required to drive the two materials separately. The reason is the occurrence of offloading work recovery. According to the above principle, the offloading work recovery ratio of the driver can be roughly calculated according to the following formula:

[0048]

[0049] where W 1 refers to the mechanical work required for a single elastocaloric material to be loaded and deformed without offloading work recovery; n refers to the number of cylinders of the driver (that is, how many materials are there in the driver); W in refers to the total mechanical work required to realize the driving process under the actual working conditions using the rotary solid-state refrigeration driver of the present disclosure (refers to the measured value); W 2 refers to the offloading mechanical work contained in a single material under the working conditions. Generally speaking, for materials with a constant elastic modulus coefficient such as springs, W 1Equal to W 2 In actual working conditions, due to the two-phase change process during the phase change of the shape memory alloy, its Young's modulus is constantly changing, which will cause hysteresis. At this time, a part of the unloading mechanical work will be converted into hysteresis heat and dissipated. Therefore, for the analysis of the shape memory alloy system, W 1 Greater than W 2 .

[0050] Based on the above principle, the exemplary embodiments of the present disclosure provide a rotary solid-state refrigeration driver (hereinafter referred to as the rotary solid-state refrigeration driver) that realizes the recovery of the unloading mechanical work of the snap-fit material under rotational motion. As Figures 2 to 5 shown. The rotary solid-state refrigeration driver includes: a rotary motor 9, a main transmission shaft 2, two eccentric transmission mechanisms, two pistons 1, and two snap-fit materials 10.

[0051] The rotary motor 9 is used to drive the main transmission shaft 2 to rotate. The two eccentric transmission mechanisms are installed at different axial positions of the main transmission shaft 2. The function of the eccentric transmission mechanism is to convert the rotational motion of the main transmission shaft 2 into a linear reciprocating motion of the piston 1, and the two snap-fit materials 10 are respectively loaded and unloaded periodically through the reciprocating motion of the two pistons 1. The phase angles of the two eccentric transmission mechanisms with respect to the main transmission shaft 2 (rotation axis O) differ by 180 degrees, so that the time periods during which the two snap-fit materials 10 are unloaded (or loaded) are staggered from each other. In other words, when one snap-fit material 10 is loaded, the other snap-fit material 10 is unloaded. During the unloading process, each snap-fit material 10 will generate a downward thrust on one of the pistons 1, and this thrust will push the piston 1 downward, thereby driving the eccentric transmission mechanism to move downward simultaneously. The transmitted thrust will act on the main transmission shaft 2 in the tangential direction to provide thrust for its rotation. Since the two snap-fit materials 10 do not provide thrust to the main transmission shaft 2 simultaneously, this thrust does not hinder the rotation of the main transmission shaft 2, but promotes the rotation of the main transmission shaft 2 and reduces the input work of the rotary motor 9.

[0052] Specifically, as Figure 2 shown, the main transmission shaft 2 can rotate around the rotation axis 0. The cross-section of the part of the main transmission shaft 2 where the eccentric transmission mechanism is installed is circular, and the center of this circle does not coincide with the rotation axis 0. In other words, the part of the main transmission shaft 2 where the eccentric transmission mechanism is installed is an eccentric circular structure with respect to the rotation axis 0 of the main transmission shaft 2, that is, the main transmission shaft 2 has a (partial) eccentric shaft structure. There is a 180-degree angular deviation in the radial direction between the two eccentric circular parts, that is, the phase angles of the two eccentric circular parts differ by 180 degrees. In addition, the eccentricity of each eccentric circular part can be set to 1.5 mm, that is, the radial distance between the centers of the two eccentric circular parts is 3 mm.

[0053] As Figure 2As shown, each eccentric drive mechanism includes a connecting rod portion 3 and a pin 4. The connecting rod portion 3 includes an upper connecting rod portion 3a and a lower connecting rod portion 3b connected together by screws. The lower end of the upper connecting rod portion 3a and the lower connecting rod portion 3b together form an annular portion. The inner diameter of the annular portion matches the outer diameter of the eccentric circular structure, so that the annular portion can be sleeved on the outer peripheral surface of the eccentric circular portion of the main transmission shaft 2 and circumferentially slide (rotate) relative to the outer peripheral surface. The other end of the connecting rod portion 3, that is, the upper end of the upper connecting rod portion 3a, is hinged to the lower end of the piston 1 through the pin 4, thereby restricting the piston 1 from moving back and forth or left and right. In addition, since the annular portion of the connecting rod portion 3 is sleeved on the eccentric circular portion with an eccentricity of 1.5 mm, when the main transmission shaft 2 rotates, the connecting rod portion 3 can swing relative to the piston 1 around the pin 4, and at the same time, the upper end of the connecting rod portion 3 drives the piston 1 to make a reciprocating motion with a stroke of about 3 mm through the pin 4.

[0054] As Figure 3 , 5 shown, the rotary solid-state refrigeration driver of the exemplary embodiment of the present disclosure may further include two linear bearings 6. Each linear bearing 6 is sleeved outside the corresponding piston 1 for providing restraint for the piston 1 and reducing frictional losses when the piston 1 moves up and down.

[0055] As Figure 5 shown, the rotary solid-state refrigeration driver of the exemplary embodiment of the present disclosure may further include two first external brackets 7b. The first external bracket 7b is a support structure for supporting the corresponding piston 1 and the elastic card material 10. The first external bracket 7b can also be used to fix the corresponding elastic card material 10. Both ends of the elastic card material 10 are fixed between the corresponding piston 1 and the first external bracket 7b in a manner of direct contact, threaded connection, welding or bonding. The first external bracket 7b can be installed on the linear bearing 6 and may include a plurality of screws fixed to the top surface of the linear bearing 6 and a top cover fixed to the screws through nuts. The position of the top cover can be adjusted through each nut, and receiving blind holes or screw holes for receiving the ends of the elastic card material 10 can be provided on the bottom surface of the top cover and the top surface of the piston 1.

[0056] As Figure 4 shown, the rotary solid-state refrigeration driver of the exemplary embodiment of the present disclosure may further include a speed reducer 8. The rotary motor 9 is connected to the main transmission shaft 2 through the speed reducer 8. The speed reducer 8 is axially connected to the rotary motor 9 and the main transmission shaft 2 for increasing the torque on the main transmission shaft 2. In addition, the rotary motor 9 of the rotary solid-state refrigeration driver of the exemplary embodiment of the present disclosure can adopt a servo motor, a stepper motor, a torque motor, a switched reluctance motor, a DC brushless motor, etc., or a mechanical device that can generate rotational motion can be adopted.

[0057] As Figure 3 and Figure 4As shown, the rotary solid-state refrigeration driver of the exemplary embodiment of the present disclosure may further include a second outer frame 7a for fixing the speed reducer 8 and the eccentric drive mechanism.

[0058] In addition, as Figure 3 shown, the rotary solid-state refrigeration driver of the exemplary embodiment of the present disclosure may further include an upper housing part 5a and a lower housing part 5b. The upper housing part 5a and the lower housing part 5b serve as housing support parts, respectively carrying the piston 1 and the main transmission shaft 2. The linear bearing 6 may be fixed on the upper housing part 5a. The lower housing part 5b may be fixedly connected to the second outer frame 7a.

[0059] It should be noted that although the rotary solid-state refrigeration driver in the exemplary embodiment of the present disclosure adopts a two-cylinder structure, that is, the number of eccentric drive mechanisms, pistons, and elastic clip materials is two, the present invention is not limited thereto, and the rotary solid-state refrigeration driver may also adopt a three-cylinder, four-cylinder or more-cylinder structure. Optionally, in the case of adopting an N-cylinder structure where N>2, the phase angle difference between any two adjacent eccentric drive mechanisms is 360 / N degrees. In other words, for any intermediate eccentric drive mechanism, if its phase angle is α, the phase angles of its adjacent front and rear eccentric drive mechanisms may be α+360 / N and α+360 / N, respectively; or, the phase angles of multiple eccentric drive mechanisms may not have an increasing / decreasing relationship, as long as they are evenly distributed within the range of 360 degrees.

[0060] Under working conditions, the rotary motor 9 drives the main transmission shaft 2 to rotate through the speed reducer 8. The eccentric circle part, connecting rod part 3, pin 4 and piston 1 of the main transmission shaft 2 constitute a crank - connecting rod structure. When the main transmission shaft 2 rotates, the eccentric circle part drives the connecting rod part 3 to vibrate up and down and swing left and right through the circular ring part. At the same time, since the upper end of the connecting rod part 3 is connected to the piston 1, and the piston 1 is restricted by the linear bearing 6, the rotation of the main transmission shaft 2 is converted into the linear reciprocating motion of the piston 1. The piston 1 loads and unloads the resilient - clamping material 10 thereon through this reciprocating motion, thereby inducing the resilient - clamping effect. The resilient - clamping effect means that when the resilient - clamping material 10 is compressed, heat is released to the environment, and when it recovers from deformation, heat is absorbed from the environment. Since multiple eccentric drive mechanisms have different phase angles relative to the main transmission shaft 2, the non - simultaneous linear reciprocating motions of multiple pistons 1 are realized. Subsequently, the time periods during which each resilient - clamping material 10 is unloaded (or loaded) by the piston 1 are different, that is, each resilient - clamping material 10 is in a different deformation stage. During the unloading process of each resilient - clamping material 10, that is, in the deformation stage from compressive deformation to deformation recovery, a downward thrust is generated on the piston 1. This thrust will push the piston 1 downward, thereby driving the eccentric drive mechanism to move downward simultaneously. The transmitted thrust will act on the main transmission shaft 2 in the tangential direction, providing thrust for its rotation. Since multiple resilient - clamping materials 10 do not provide thrust to the main transmission shaft 2 simultaneously, this thrust can reduce the torque required to load other resilient - clamping materials, realize work recovery, promote the uniform rotation of the main transmission shaft 2, reduce the input work of the rotary motor 9, and achieve power saving and energy conservation.

[0061] Optionally, although the eccentric drive mechanism according to the present disclosure preferably can have the structure described in the above - mentioned embodiments, it can also have other structures. For example, the eccentric drive mechanism can cooperate with the main transmission shaft 2 and the piston 1 to form an eccentric - connecting - rod mechanism, an eccentric - cam mechanism, an eccentric - bearing mechanism or a crank - connecting - rod mechanism. For example, when an eccentric - cam mechanism is adopted, the main transmission shaft 2 may not be provided with an eccentric - circle structure, and the cam fixed on the main transmission shaft 2 can directly replace the connecting - rod part 3. The cam surface of the cam contacts the bottom of the piston 1 (so as to push the piston 1 when loading the resilient - clamping material or be pushed by the piston 1 when unloading the resilient - clamping material), and each cam has a different phase angle.

[0062] Optionally, the resilient - clamping material 10 is selected from shape - memory alloys, natural rubbers, synthetic polymers, plastic crystals, etc. When the resilient - clamping material 10 is a shape - memory alloy, it can be selected from the group including the following: nickel - titanium alloy, copper - aluminum - manganese alloy, nickel - manganese - titanium alloy, nickel - titanium - cobalt alloy, nickel - titanium - copper - cobalt alloy, nickel - iron - gallium alloy.

[0063] Optionally, the eccentric drive mechanism, piston 1, main drive shaft 2, linear bearing 6, upper housing part 5a, and lower housing part 5b are formed of plastic, metal, resin, or other materials by additive manufacturing (such as 3D printing) or subtractive manufacturing (such as wire cutting).

[0064] Optionally, the rotation mode of the main drive shaft 2 can be set to uniform rotation, differential rotation, or intermittent rotation.

[0065] Optionally, the deformation mode of the loading-unloading process of each elastic card material 10 is uniaxial linear deformation including linear compression and linear tension.

[0066] The following further elaborates on the rotary solid-state refrigeration driver of the present disclosure in combination with experiments.

[0067] Related tests

[0068] The structure of the rotary solid-state refrigeration driver used in this experiment is as Figures 2 to 5 shown. The linear bearing 6, second outer frame 7a, first outer frame 7b, speed reducer 8, and elastic card material 10 used are commercial standard parts; among them, the piston 1, main drive shaft 2, upper connecting rod part 3a, lower connecting rod part 3b, pin 4, upper housing part 5a, and lower housing part 5b are machined alloy components. The components are connected to each other by screws. The rotary motor 9 is a servo motor. In the experiment, in order to achieve a better display effect, a spring is used to replace the elastic card material 10.

[0069] The operation process of the rotary solid-state refrigeration driver is as Figure 1 shown. By the rotation of the rotary motor 9, the main drive shaft 2 rotates, and the eccentric drive mechanism converts the rotation into a linear reciprocating motion of the piston 1, thereby compressing the spring. Reverse unloading elastic mechanical work recovery means that after the spring is unloaded, it pushes the main drive shaft 2 to rotate, thereby reducing the required torque of another loaded spring.

[0070] The torque sensor is axially installed between the main drive shaft 2 and the speed reducer 8 to measure the torque change on the main drive shaft 2. Two springs replacing the elastic card material 10 are respectively installed in the two cylinders of the rotary solid-state refrigeration driver of the present disclosure. Among them, initially, one spring is in a compressed state, that is, in a loaded state; the other spring is in a non-deformed state, that is, in an unloaded state. After installing the springs, start the rotary motor 9 and set the rotary motor 9 to work in a uniform rotation mode, and the rotation speed is set to 16 revolutions per minute. The data of the torque on the shaft changing with the rotation angle of the drive shaft is collected and recorded by the torque sensor. For comparison, the torque change of the solid-state refrigeration driver with only a single spring installed is collected.

[0071] The experimental results are as Figure 6As shown in the figure, the area enclosed by the torque change curve on the shaft and the horizontal axis of the rotation angle is the input work of the rotary motor 9. It can be seen that the input work required to drive two materials simultaneously and use the elastic unloading work of one material to drive the other material to load is smaller than the input work required to drive the two materials separately (the area enclosed by the torque curve of a single material is twice that of the torque curves of two materials). According to the principle described above, the recovery ratio of the unloading work of the driver can be roughly calculated by the following formula:

[0072]

[0073] Where W 1 refers to the mechanical work required for a single elastic card material to be loaded and deformed without unloading work recovery, which refers to the area enclosed by the torque curve of a single material here; the number 2 represents the number of cylinders of the driver (i.e., how many materials are in the driver); W in refers to the total mechanical work required to realize the driving process under the actual working conditions by using the rotary solid-state refrigeration driver of the present disclosure (refers to the measured value), which refers to the area enclosed by the torque curves of two materials here; W 2 refers to the unloading mechanical work contained in a single material under the working conditions. Generally speaking, for materials with a constant elastic modulus coefficient such as springs, W 1 is equal to W 2 . Through calculation, the work recovery ratio is obtained as 53%, indicating that the rotary solid-state refrigeration driver of the present disclosure has the function of unloading work recovery. By recovering the unloading elastic mechanical work of the material, the input work required by the rotary motor will be reduced, and the system operation can be maintained, that is, the requirement of reducing energy consumption is met.

[0074] Accordingly, compared with the prior art, the rotary solid-state refrigeration driver of the present disclosure has the following advantages:

[0075] 1. In terms of structural design: The present disclosure adopts a rotary loading method. Compared with the existing hydraulic or linear motor drive, the number of mechanical transmission devices is greatly reduced, thereby reducing the mechanical energy and electrical energy losses. The multi-cylinder arrangement method is adopted to greatly reduce the overall length, making the overall structure more compact.

[0076] 2. In terms of energy utilization: The rotary solid-state refrigeration driver of the present disclosure realizes the recovery of unloading mechanical work. The unloading mechanical work of one elastic card material is recovered and reused to load another elastic card material, achieving energy recovery and utilization and reducing energy consumption. Compared with traditional elastic card materials that need to wait for heat dissipation before using the cooling capacity, due to the multi-cylinder design of this driver, the intermittent refrigeration of multiple elastic card materials can be superimposed into continuous refrigeration, greatly improving the efficiency and refrigeration power. By adjusting the eccentric distance, the maximum temperature drop of the elastic card material per single time can reach 30 degrees. The recovery of unloading mechanical work does not require additional waiting time, and the overall driving operation frequency can be increased, up to a running frequency of 5 Hz, thereby obtaining a large refrigeration power.

[0077] 3. In terms of commercial applications: Compared with existing hydraulic or linear motor drives, the rotary solid-state refrigeration driver of the present disclosure significantly reduces the overall weight and volume, improving safety and portability. At the same time, during the operation of the driver, since it only involves rotational motion and there is no additional mechanical transmission device, the overall mechanical stability is high and the safety factor of use is high. Most importantly, the recovery of unloading mechanical work is realized, and the energy consumption coefficient of the elastic card solid-state refrigerator will exceed that of existing air conditioners, not only reducing the electricity expenditure of consumers, but also meeting the requirements of environmental protection and carbon neutrality.

[0078] In summary, the rotary solid-state refrigeration driver of the present disclosure utilizes the elastic mechanical energy stored by the elastic card material during the unloading process, realizes the recovery and utilization of unloading mechanical work, reduces the electric energy consumption required for the overall driver, improves the energy consumption ratio and the stability of the driver during operation, providing new possibilities for the development of lightweight and commercial elastic card solid-state refrigeration devices.

[0079] In the second aspect, the present disclosure also provides a solid-state refrigeration device, which includes the rotary solid-state refrigeration driver based on the recovery of unloading mechanical work described above, and further includes a heat exchange structure for exchanging heat with the elastic card material to transfer the heat and cold generated by the elastic card material.

[0080] Optionally, the heat exchange structure can be a solid heat exchanger (transferring heat directly through solid-solid contact) or a fluid heat exchanger (using gases, liquids, liquid metals, etc. for solid-liquid convective heat exchange).

[0081] Since this solid-state refrigeration device includes the rotary solid-state refrigeration driver described above, it has all the advantages of this rotary solid-state refrigeration driver.

[0082] It is understandable that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present disclosure. However, the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

1. A rotary solid-state refrigeration driver based on the recovery of unloading mechanical work, Characterized in that, The rotary solid-state refrigeration driver includes: a rotary motor, a main transmission shaft driven by the rotary motor to rotate, N eccentric transmission mechanisms installed at different axial positions of the main transmission shaft and all driven by the main transmission shaft, N pistons respectively driven by the N eccentric transmission mechanisms to perform reciprocating motions, and N elastocaloric materials respectively periodically loaded-unloaded through the reciprocating motions of the N pistons, wherein, N is an integer greater than 1; The N eccentric transmission mechanisms have different phase angles relative to the main transmission shaft, such that the periods during which the N elastocaloric materials are unloaded are different; and Each elastocaloric material provides a thrust for the rotation of the main transmission shaft by releasing its own mechanical work during the unloading process.

2. The rotary solid-state refrigeration driver according to claim 1, Characterized in that, Along the axial direction of the main transmission shaft, the difference in the phase angles between any two adjacent eccentric transmission mechanisms among the N eccentric transmission mechanisms is 360 / N degrees.

3. The rotary solid-state refrigeration driver according to claim 1 or 2, Characterized in that, The eccentric transmission mechanism cooperates with the main transmission shaft and the piston to form an eccentric connecting rod mechanism, an eccentric cam mechanism, an eccentric bearing mechanism or a crank connecting rod mechanism.

4. The rotary solid-state refrigeration driver according to claim 1 or 2, Characterized in that, At each of the different axial positions of the main transmission shaft: The cross-section of the main transmission shaft is circular and the center of the circle does not coincide with the rotation axis of the main transmission shaft; and The eccentric transmission mechanism includes a connecting rod part and a pin. The end of the connecting rod part away from the piston includes a circular ring part. The circular ring part is sleeved on the outer peripheral surface of the main transmission shaft and can slide circumferentially relative to the outer peripheral surface of the main transmission shaft. The other end of the connecting rod part is hinged to the end of the piston away from the elastocaloric material through the pin.

5. The rotary solid-state refrigeration driver according to claim 4, Characterized in that, The connecting rod part includes an upper connecting rod part and a lower connecting rod part. The circular ring part is composed of the lower part of the upper connecting rod part and the lower connecting rod part. The upper connecting rod part and the lower connecting rod part are connected together by screws.

6. The rotary solid-state refrigeration driver according to claim 5, Characterized in that, It further includes: A linear bearing sleeved outside the corresponding piston for defining the direction of the reciprocating motion of the piston; A first external frame for supporting the corresponding piston and elastocaloric material. Both ends of each elastocaloric material are fixed between the corresponding piston and the first external frame in a direct contact, threaded connection, welding or bonding manner; And / or An upper housing part and a lower housing part respectively used for carrying the piston and the main transmission shaft.

7. The rotary solid-state refrigeration driver according to claim 1 or 2, Characterized in that, The rotary motor is selected from: servo motor, stepper motor, torque motor, switched reluctance motor, brushless DC motor, and The rotary solid-state refrigeration driver further includes a speed reducer, and the rotary motor drives the main transmission shaft to rotate through the speed reducer.

8. The rotary solid-state refrigeration driver according to claim 7, wherein, it further includes a second outer frame for fixing the speed reducer and the eccentric transmission mechanism.

9. The rotary solid-state refrigeration driver according to claim 1 or 2, wherein, the geometric shape of the elastic card material is selected from: cylindrical, cubic, cuboid, circular tube, rectangular tube; and the elastic card material is selected from: shape memory alloy, natural rubber, synthetic polymer, plastic crystal.

10. The rotary solid-state refrigeration driver according to claim 1 or 2, wherein, the deformation mode of the loading-unloading process of the elastic card material is uniaxial linear deformation, and the uniaxial linear deformation includes linear compression and linear tension.

11. A solid-state refrigeration device, comprising; a rotary solid-state refrigeration driver based on unloading mechanical work recovery according to any one of claims 1 to 10; and a heat exchange structure for exchanging heat with the elastic card material to transfer the heat and cold generated by the elastic card material.

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