WO2016151416A1

WO2016151416A1 - Metal hydride heat pump providing continuous uniform output

Info

Publication number: WO2016151416A1
Application number: PCT/IB2016/050931
Authority: WO
Inventors: Devadatta Pundlik NAVALE
Original assignee: Thermax Limited
Priority date: 2015-03-25
Filing date: 2016-02-22
Publication date: 2016-09-29

Abstract

A metal hydride heat pump (100) is disclosed. The metal hydride heat pump (100) comprises a first module (102) including a first metal hydride reactor assembly (106) and a second module (104) including a second metal hydride reactor assembly (108). The first and the second modules are partitioned into a plurality of insulated chambers, each chamber of said first and second modules comprising a portion of said first and second metal hydride reactor assemblies, respectively. A portion of said first metal hydride reactor assembly (106) is connected to a portion of the second metal hydride reactor assembly (108) via a hydrogen tubing unit (110). The heat pump is a continuous operation metal hydride heat pump which provides continuous uniform output, minimizes temperature variations and enhances the system performance.

Description

METAL HYDRIDE HEAT PUMP PROVIDING CONTINUOUS UNIFORM OUTPUT

FIELD OF THE DISCLOSURE

The present disclosure relates to a metal hydride heat pump.

More particularly, the present disclosure relates to a metal hydride heat pump having a constant uniform output.

BACKGROUND

Metals or alloys react with hydrogen exothermic ally to produce metal hydrides, and the metal hydrides reversibly release hydrogen gas endothermically. LaNi₅H_x, MmNi₅H_x, MmCo₅H_x, FeTiH_x, VNbH_x and Mg₂ CuH are common examples of metal hydrides which have the ability to occlude a significant amount of hydrogen and release a large amount of the heat of reaction. Various metal hydride devices are known, such as heat pumps/air conditioning devices, which utilize these properties of metal hydrides to provide heating and/or refrigeration. Hydrogen is used as a refrigerant and metal hydrides are used as absorbents.

A conventional metal hydride heat pump comprises a first receptacle filled with a first metal hydride, a second receptacle filled with a second metal hydride, the first and the second metal hydrides having different equilibrium dissociation characteristics, a hydrogen flow pipe connecting these receptacles, and heat exchangers provided in the respective receptacles. Typically, a heating output and a cooling output based on the heat generation and absorption of the metal hydrides within the receptacle is obtained by means of a medium flowing within the heat exchangers.

The metal hydride heat pump operates in a cyclic manner. A pair of two different types of metal hydrides are used, viz., regenerating alloy A and refrigerating alloy B, as sorbents, and hydrogen as a refrigerant. In the first cycle of operation of the paired reactors of alloys A & B, alloy A discharges hydrogen using a first medium of high temperature as a heat source. The discharged hydrogen is absorbed by alloy B and in the process heat is conducted/transmitted to a second medium, typically ambient air. In the second cycle alloy B desorbs hydrogen using a third stream of low temperature heat source. The discharged hydrogen is absorbed by alloy A and in the process heat is transmitted/conducted to the fourth stream, typically ambient air. Thus, the operation of the metal hydride heat pump requires each alloy to go through a temperature swing for charging and discharging. Due to the cyclic operation of the system, the output varies with time during the cycle. FIGURE 1 of the accompanying drawing illustrates a graph showing the inlet air temperature (A) and the cold air outlet temperature (B) of a typical metal hydride heat pump. It can be seen that the cold air outlet temperature (B) is not constant, and the variation can be up to + 6 °C when compared to the average outlet temperature (C). Thus, large temperature variations are observed which lead to underperformance of the system. Further, dampers, ducting and the casing of the heat pump form a part of the thermal cycling, which results in increased thermal inertia. Higher thermal inertia is highly undesirable for the system and results in reduced performance. Also, the arrangement of the reactor casings connected with multiple dampers by interconnecting ducting requires multiple bends and higher flow length for the air streams used as the heat transfer medium. This results in higher pressure drop in the system requiring higher power for the air fans and blowers. Thus, the air distribution is not uniform resulting in reduced performance. Additionally, since multiple dampers are connected to the reactor casing by interconnecting ducting, this makes the system bulky and heavy. Also, the interconnecting ducting results in increased height of the system which is undesirable for applications such as mobile air conditioning in vehicles, due to the increased drag force on the vehicle. There is therefore need for a metal hydride heat pump that overcomes the above-noted drawbacks of the conventional metal hydride heat pumps and provides a constant uniform output. OBJECTS

Some of the objects of the system of the present disclosure, which at least one embodiment herein satisfies, are as follows:

It is an object of the present disclosure to provide an improved continuous operation metal hydride heat pump which provides a constant uniform output.

It is another object of the present disclosure to provide a metal hydride heat pump which minimizes temperature variations and enhances the system performance.

It is yet another object of the present disclosure to provide a metal hydride heat pump that has reduced thermal inertia.

It is still another object of the present disclosure to provide a metal hydride heat pump that has reduced pressure drop in the heat transfer medium while flowing through the heat pump, thereby reducing the power consumption in running fans and blowers.

One more object of the present disclosure is to provide a metal hydride heat pump which gives uniform air distribution in the reactor assembly.

Still one more object of the present disclosure is to provide a metal hydride heat pump which is compact, has a reduced weight and a reduced height, which decreases the drag forces on a vehicle.

Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure. SUMMARY

In accordance with an embodiment of the present disclosure, there is provided a metal hydride heat pump comprising:

a first module and a second module connected by means of a hydrogen tubing unit (110);

a first metal hydride reactor assembly and a second metal hydride reactor assembly positioned inside said first module and said second module, respectively; wherein, said first module and said second module are each partitioned into a plurality of insulated chambers such that each chamber of said first module has within it a portion of said first metal hydride reactor assembly and each chamber of said second module has within it a portion of said second metal hydride reactor assembly, each of said portions within said insulated chambers comprises a fin and tube arrangement, wherein the tubes of the fin and tube arrangement of the insulated chambers of said first and second modules comprise a regenerating alloy and a refrigerating alloy respectively, and each tube of the fin and tube arrangement disposed within each chamber of said plurality of insulated chambers in said first module is connected via said hydrogen tubing unit to one of the tubes of the fin and tube arrangement disposed within a chamber of said plurality of insulated chambers of said second module, such that, said metal hydride reactor assemblies operatively connected via said tubing unit are configured to rotate about an axis.

Typically, in accordance with the present disclosure, a bearing assembly can be provided for supporting said metal hydride reactor assemblies, said bearing assembly supports a shaft that is coupled to a drive mechanism for rotating, about an axis, said operatively connected metal hydride reactor assemblies via said tubing unit.

Preferably, in accordance with the present disclosure, each of said chambers comprises an inlet and an outlet for a heat transfer medium. Each of said chambers receives a different stream of said heat transfer medium. Typically, in accordance with the present disclosure, partitioning means is provided to create a partition in said metal hydride reactor assemblies for preventing mixing of said heat transfer medium between said chambers. Additionally, at least one flexible seal is provided in each of said metal hydride reactor assemblies for preventing mixing of said heat transfer medium between said chambers. Furthermore, at least one air seal is provided in each of said metal hydride reactor assemblies for preventing short circuiting of said heat transfer medium between said inlet and said outlet of said chambers. The present disclosure provides a method of operation of the metal hydride heat pump comprising the step of rotating the operatively connected metal hydride reactor assemblies continuously in one direction at a selective low speed.

The present disclosure also provides a method of operation of the metal hydride heat pump comprising the step of rotating the operatively connected metal hydride reactor assemblies in a step-wise manner in a pre-defined direction at a selective low speed in a cyclic frequency. The frequency is based on at least one pre-defined condition. The pre-defined direction may be in clockwise direction or anti-clockwise direction or both.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

The metal hydride heat pump having a constant uniform output of the present disclosure will now be described with the help of the accompanying drawing, in which:

FIGURE 1 illustrates a graphical representation of the inlet air temperature and the cold air outlet temperature of a typical conventional cyclic metal hydride heat pump;

FIGURE 2 illustrates a graphical comparison of the outlet air temperature of the continuous operation metal hydride heat pump of the present disclosure and a typical conventional cyclic metal hydride heat pump; FIGURE 3 illustrates a graphical comparison of the outlet air temperature for multiple incremental changeover steps using the metal hydride heat pump of the present disclosure and a typical conventional cyclic metal hydride heat pump;

FIGURE 4 illustrates a preferred embodiment of the continuous operation metal hydride heat pump of the present disclosure;

FIGURE 5 illustrates a front-view of the preferred embodiment of the continuous operation metal hydride heat pump of FIG. 4; and

FIGURE 6 illustrates a schematic of the fin geometry of the metal hydride reactor assembly of the preferred embodiment of the continuous operation metal hydride heat pump of FIG. 4.

DETAILED DESCRIPTION

A metal hydride heat pump having a constant uniform output of the present disclosure will now be described with reference to the embodiments which do not limit the scope and ambit of the disclosure.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The metal hydride heat pump of the present disclosure includes a cylindrical metal hydride reactor assembly, which can be rotated between the absorption mode and the desorption mode. Thus, only the metal hydride reactor assembly with the support structure is rotated for the changeover of the streams of the heat transfer medium. Hence, the heat pump of the present disclosure provides a continuous operation. The continuous operation metal hydride heat pump avoids sudden step changes due to cycle changeover and provides continuous uniform output. The present disclosure provides a multiple steps incremental changeover system. In the heat pump of the present disclosure the number of steps can be increased by smaller rotation angles in each cycle time, i.e. instead of rotating by 180° for each changeover, the heat pump can be rotated twice by 90° or thrice by 60°, and so on.

Continuous rotation avoids sudden changes in the process parameters, and hence provides a continuous uniform output. FIGURE 1 of the accompanying drawing shows the inlet air temperature (A) and the cold air outlet temperature (B) of a typical cyclic metal hydride heat pump. It can be seen that the cold air outlet temperature (B) is not constant, and the variation can be up to + 6 °C when compared to the average outlet temperature (C). FIGURE 2 of the accompanying drawing shows a comparison of the outlet air temperature of the continuous operation metal hydride heat pump of the present disclosure (E) and the outlet air temperature of a typical conventional cyclic metal hydride heat pump (D). It is observed that the continuous operation provides a continuous uniform output air temperature (E). A uniform output air temperature is also obtained in the system with multiple incremental changeover steps. FIGURE 3 of the accompanying drawings illustrates a comparison of the outlet air temperature for multiple incremental changeover steps using the metal hydride heat pump of the present disclosure (G) and the outlet air temperature of a typical conventional cyclic metal hydride heat pump (F). FIGURE 3 shows temperature variations for a system which has three steps of rotation in a half cycle of operation (i.e. 180°).

As sudden changes are avoided in the continuous system, the temperature variations are very small, this gives optimum system performance. In case of the multiple incremental changeover steps by small rotations, the sudden change of parameters is distributed over multiple steps; this gives reduced temperature variations and better system performance. The rotating arrangement results in reduced thermal inertia. The reactor casing remains stationary during the operation cycle, and after the changeover, it experiences the same heat transfer medium stream. Since the casing does not contribute to the temperature cycling, the thermal inertia of the system is reduced, resulting in higher performance. Also, the system has no or very little ducting, which reduces the ducting thermal inertia, thereby improving the system performance.

Further, the arrangement of the present disclosure has fewer bends and a reduced flow length for the heat transfer medium, which decreases the pressure drop in the medium across the heat pump. The decreased pressure drop reduces the energy consumption of running air fans and blowers. The arrangement provides uniform air distribution over the reactor modules as dampers and interconnecting ducting are absent. The absence of dampers and ducting also reduces the size, weight and height of the metal hydride heat pump, and assists in reducing the drag forces on a vehicle in dynamic applications. The heat pump uses one or more sets of paired refrigerating and regenerating alloy metal hydride reactor modules to give continuous cooling, as each pair provides an output only during a half cycle. The paired reactors are arranged in such a way so as to make the system compact. FIGURES 4 & 5 of the accompanying drawings illustrate one embodiment of the metal hydride heat pump of the present disclosure; the heat pump is generally referenced by the numeral 100 in the FIGS. 4 & 5. FIG. 4 shows the side-view and FIG. 5 shows the front-view of the preferred embodiment of the metal hydride heat pump. The metal hydride heat pump 100 comprises a first module 102 and a second module 104. The first module 102 contains a first metal hydride reactor assembly 106 and the second module 104 contains a second metal hydride reactor assembly 108. The first metal hydride reactor assembly 106 of the first module 102 and the second metal hydride reactor assembly 108 of the second module 104 are operatively connected by means of a hydrogen tubing unit 110 for supply of Hydrogen. The reactor casings 116 & 118 are provided for the metal hydride reactor assemblies to guide air streams through the metal hydride reactor assembles & to isolate them from the atmosphere. The first module 102 and the second module 104 both are partitioned into a plurality of insulated chambers. Each of the chambers in the first module 102 and the second module 104 includes an inlet and an outlet for a heat transfer medium. Each of the chambers receives a different stream of the heat transfer medium, which is typically air. The outer casings 116 & 118 are adapted to guide streams of the heat transfer medium through the chambers of the modules 102 & 104, respectively, and also insulate the chambers.

The first metal hydride reactor assembly 106 and the second metal hydride reactor assembly 108 are supported on a shaft 114 along the partition by means of a supporting structure 112. The shaft 114 is supported by a bearing assembly 120. The bearing assembly 120 supports the first metal hydride reactor assembly 106 and the second metal hydride reactor assembly 108. The bearing assembly 120 is firmly supported on a baseframe 122. The bearing assembly 120 supports a shaft that is coupled to a drive mechanism having a reduction gear box adapted to rotate the metal hydride reactor assemblies 106 and 108 of the first module 102 and the second module 104 respectively along with the shaft 114 and the supporting structure 112 centrally about the partition. Partitioning means 124 are provided to create a partition of the metal hydride reactor assemblies 106 & 108 between the outer casing and the metal hydride reactor assemblies for preventing mixing of different streams of the heat transfer medium flowing through each of the chambers. Also, one or more flexible seals 126 are provided in the metal hydride reactor assemblies 106 & 108 for preventing mixing of the different streams of the heat transfer mediums between the chambers while the metal hydride reactor assemblies are rotating or are stationary, and to prevent bypassing of the streams in the chambers. Additionally, one or more air seals 128 are provided inside the metal hydride reactor assemblies 106 & 108 for preventing short circuiting of the heat transfer mediums between the inlet and the outlet of the chambers, while the metal hydride reactor assemblies are rotating or are stationary. The air seals 128 are installed on the outer casing 116 & 118 or the stationary baseframe 122 of the heat pump 100. The air seals 128 are made of a flexible material.

The chambers have a fin and tube arrangement. The fin and tube arrangement is shown in the FIGURE 6 of the accompanying drawings. The fin and tube arrangement comprises a circular fin with a central hole, such as a doughnut. The fin includes plurality of punched holes 130 for the tubes. The tubes are inserted axially through each of the holes 130 provided on the fin to define the fin and tube arrangement of the metal hydride reactor assembly. Filter with metal hydride powder is assembled inside the tubes of the fin and tube arrangement forming the metal hydride reactor assembly. The tubes of the fin and tube arrangement of the insulated chambers of said first and second modules comprise a regenerating alloy and a refrigerating alloy respectively, and each tube of the fin and tube arrangement disposed within each chamber of said plurality of insulated chambers in said first module 102 is connected via said hydrogen tubing unit 110 to one of the tubes of the fin and tube arrangement disposed within a chamber of said plurality of insulated chambers of said second module 104, such that, said metal hydride reactor assemblies 106 & 108 operatively connected via said tubing unit 110 are configured to rotate about an axis. This allows each tube pair (one tube from the first metal hydride reactor assembly 106 and one tube from the second metal hydride reactor assembly 108) to independently act as a mini metal hydride heat pump where each tube can be operated at a different pressure and temperature condition. This also enables the metal hydride reactor assemblies 106 & 108 connected via the tubing unit 110 to rotate about the partition during the operation, and during each small rotation only one or few tubes see the cycle change.

As shown in FIGURE 4, the first module 102 receives Stream 1 (SI) and Stream 2 (S2) in its chambers. Stream 1 (SI) is ambient air, which is used for transmitting heat during the hydrogen absorption process in the portion of the metal hydride reactor assembly 106 in the chamber that receives stream 1 (SI). Stream 2 (S2) is hot air, which acts as a heat source for desorbing hydrogen at high pressure and high temperature in the portion of the metal hydride reactor assembly 106 in the chamber that recives stream 2 (S2). The second module 104 receives Stream 3 (S3) and Stream 4 (S4) in its chambers. Stream 3 (S3) is cold air, which acts as a low temperature heat source, and which is further cooled in the portion of the metal hydride reactor assembly 108 in the chamber that receives stream 3 (S3) during the desorption process. Stream 4 (S4) is ambient air, which is used for transmitting heat during the hydrogen absorption process in the portion of the metal hydride reactor assembly 108 in the chamber that receives stream 4 (S4). The portion of the metal hydride reactor assembly 106 in the chamber of the first module 102 receiving Stream 1 (SI) is operatively connected via the tubing unit 110 to the portion of the metal hydride reactor assembly 108 in chamber of the second module 104 receiving the Stream 3 (S3). The portion of the metal hydride reactor assembly 106 in the chamber of the first module 102 receiving Stream 2 (S2) is operatively connected via the tubing unit 110 to the portion of the metal hydride reactor assembly 108 in the chamber of the second module 104 receiving the Stream 4 (S4). The hydrogen desorbed in the metal hydride reactor assembly 106 in the chamber of the first module 102 receiving the Stream 2 (S2) is absorbed in the metal hydride reactor assembly 108 in the chamber of the second module 104 receiving the Stream 4 (S4). The hydrogen desorbed in the metal hydride reactor assembly 108 in the chamber of the second module 104 receiving the Stream 3 (S3) is absorbed in the metal hydride reactor assembly 106 in the chamber of the first module 102 receiving the Stream 1 (SI).

When the metal hydride heat pump 100 is operated in the continuous changeover mode, the metal hydride reactor assemblies 106 & 108 are continuously rotated in the same direction at a very low speed during the operation. For example: In an operation cycle of 8 minutes, the metal hydride reactor assemblies 106 & 108 may be rotated at 0.125 revolutions per minute or 7.5 revolutions per hour. The variations in the outlet temperature of all the streams are substantially reduced due to the multiple rotations as the thermal inertia of the heat pump is equally divided in the complete cycle. Thus, a continuous uniform output is obtained. In case of a conventional cyclic system, there is a sudden cycle change during each half cycle time resulting in higher outlet temperature variations in all the air streams. When the metal hydride heat pump 100 is operated in the step-wise changeover mode, the metal hydride reactor assemblies 106 & 108 are rotated according to a pre-defined condition in a clockwise direction or anti-clock wise direction at a very low speed, in a cyclic frequency and said frequency is based on at least one pre-defined condition. For example: In an operation cycle of 8 minutes, the chambers of the first and second modules 102 and 104 may be rotated thrice by 60° with a stay period of 80 seconds. Thus, the chambers of the first and the second modules 102 and 104 will be rotated 6 times in each cycle. The variations in the outlet temperature of all the streams are substantially reduced due to the multiple rotations as the thermal inertia of the heat pump is equally divided in the complete cycle. Thus, a continuous uniform output with minimum variations is obtained.

TECHNICAL ADVANCEMENT

The metal hydride heat pump, as described in the present disclosure, has several technical advantages including, but not limited to, the realization of:

- it is a continuous operation metal hydride heat pump which provides constant uniform output;

- minimizes temperature variations and enhances the system performance;

- reduces the thermal inertia;

- reduces pressure drop in the heat transfer medium while flowing through the heat pump, thereby reducing the power consumption in running fans and blowers;

- gives uniform air distribution in the metal hydride reactor assembly; and

- is compact, has a reduced weight, and a reduced height, which decreases the drag forces on the vehicle Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the invention as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the invention, unless there is a statement in the specification specific to the contrary.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

CLAIMS:

1. A metal hydride heat pump (100) comprising:

a first module (102) and a second module (104) connected by means of a hydrogen tubing unit (110);

a first metal hydride reactor assembly (106) and a second metal hydride reactor assembly (108) positioned inside said first module (102) and said second module (104), respectively;

wherein, said first module (102) and said second module (104) are each partitioned into a plurality of insulated chambers such that each chamber of said first module (102) has within it a portion of said first metal hydride reactor assembly (106) and each chamber of said second module (104) has within it a portion of said second metal hydride reactor assembly (108), each of said portions within said insulated chambers comprises a fin and tube arrangement, wherein the tubes of the fin and tube arrangement of the insulated chambers of said first and second modules comprise a regenerating alloy and a refrigerating alloy respectively, and each tube of the fin and tube arrangement disposed within each chamber of said plurality of insulated chambers in said first module (102) is connected via said hydrogen tubing unit (110) to one of the tubes of the fin and tube arrangement disposed within a chamber of said plurality of insulated chambers of said second module (104), such that, said metal hydride reactor assemblies (106,108) operatively connected via said tubing unit (110) are configured to rotate about an axis.

2. The metal hydride heat pump (100) as claimed in claim 1, wherein said metal hydride reactor assemblies (106, 108) are provided with a bearing assembly (120) supporting a shaft that is coupled to a drive mechanism for rotating, about an axis, said metal hydride reactor assemblies (106,108) operatively connected via said tubing unit (110).

3. The metal hydride heat pump (100) as claimed in claim 1, wherein each insulated chamber of said plurality of insulated chambers of said first and second modules (102,104) comprises an inlet and an outlet for a heat transfer medium.

4. The metal hydride heat pump (100) as claimed in the claim 3, wherein each chamber of said plurality of insulated chambers of said first and second modules (102,104) receives a different stream of said heat transfer medium.

5. The metal hydride heat pump (100) as claimed in claim 1 or claim 4, wherein each of said metal hydride reactor assemblies (106, 108) is provided with a partitioning means (124) to create a partition for preventing mixing of said different streams of said heat transfer medium between said chambers.

6. The metal hydride heat pump (100) as claimed in claim 1 or claim 4, wherein at least one flexible seal (126) is provided in each of said metal hydride reactor assemblies (106, 108) for preventing mixing of said different streams of said heat transfer medium between said chambers.

7. The metal hydride heat pump (100) as claimed in claim 1 or claim 3, wherein each of said metal hydride reactor assemblies (106, 108) is provided with one or more air seal(s) (128) for preventing short circuiting of said heat transfer medium between said inlet and said outlet of said chambers.

8. A method of operation of a metal hydride heat pump comprising a first module including a first metal hydride reactor assembly and a second module including a second metal hydride reactor assembly, each of said first and said second modules being partitioned into a plurality of insulated chambers such that each chamber of said first module has within it a portion of said first metal hydride reactor assembly and each chamber of said second module has within it a portion of said second metal hydride reactor assembly, each of said portions within said insulated chambers comprises a fin and tube arrangement, wherein the tubes of the fin and tube arrangement of the insulated chambers of said first and second modules comprise a regenerating alloy and a refrigerating alloy respectively, and each tube of the fin and tube arrangement disposed within each chamber of said plurality of insulated chambers in said first module is connected via a hydrogen tubing unit to one of the tubes of the fin and tube arrangement disposed within a chamber of said plurality of insulated chambers of said second module, said method comprising the step of rotating said operatively connected metal hydride reactor assemblies continuously in one direction at a selective low speed.

9. A method of operation of a metal hydride heat pump comprising a first module including a first metal hydride reactor assembly and a second module including a second metal hydride reactor assembly, each of said first and said second modules being partitioned into a plurality of insulated chambers such that each chamber of said first module has within it a portion of said first metal hydride reactor assembly and each chamber of said second module has within it a portion of said second metal hydride reactor assembly, each of said portions within said insulated chambers comprises a fin and tube arrangement, wherein the tubes of the fin and tube arrangement of the insulated chambers of said first and second modules comprise a regenerating alloy and a refrigerating alloy respectively, and each tube of the fin and tube arrangement disposed within each chamber of said plurality of insulated chambers in said first module is connected via a hydrogen tubing unit to one of the tubes of the fin and tube arrangement disposed within a chamber of said plurality of insulated chambers of said second module, said method comprising the step of rotating said operatively connected metal hydride reactor assemblies in a step-wise manner in a pre-defined direction at a selective low speed in a cyclic frequency and said frequency is based on at least one pre-defined condition.

10. The method of operation of a metal hydride heat pump as claimed in claim 9, wherein said pre-defined direction is at least one of the following: a) a clockwise direction; and b) an anti-clockwise direction.