Description:TECHNICAL FIELD
[001] The present disclosure relates to a heat management system, more particularly relates to a hybrid cold plate having combination of active and passive cooling/heating technology.

BACKGROUND
[002] Heat Sinks and Cold Plates are primarily used as heat management system. Further a cold plate is used in application that have size constraint and need high energy absorption. The size constraint and high energy absorption by cold plates is enabled by passages provided within the cold plates. The passages are further configured to contain coolant to extract the heat from the source/target and transfer away by pumping.
[003] The cold plates usually used to extract heat from a heat source, by moving a low temperature coolant within the cold plate surface. The low temperature coolant is directed towards the inlet into of the passage provided in the cold plate. The coolant as it passes through the flow channels/passages extracts the heat from the source the cold plate.
[004] Thus, the flow of heat energy during a cooling operation is from the target body into the cold plate and from the surface of the cold plate the heat flows into the coolant. The heat absorbed by the coolant is then released in a heat sink which can be radiator fan arrangement. The heat extraction using a cold plate is termed as active cooling since an active power consuming part like a pump is used to direct the coolant into the cold plate. The active cooling methods provide enable rapid exchange of heat as compared to passive cooling methods since the heat transfer rate is high. The heat transfer rate within the active cooling methods like cold plate can be significantly varied by changing the flow parameters like mass flow rate of the coolant, temperature of the coolant etc.
[005] However, one of the major drawbacks of the cold plate is the region where the coolant enters is favoured more in terms of heat transfer whereas the region where the coolant leaves is favoured less. Further the coolant flow leads to temperature gradient within the cold plate and forms temperature hotspots/cold spots. Typically, the region wherein the coolant enters the cold plate shows a lower temperature whereas the region near the outlet port of the coolant has a relatively high temperature due to the cascading effect of heat addition. The formation of these temperature gradients and temperature hotspots is undesirable since it leads to uneven heat extraction from the target body. Typical solution to tackle this problem is to design the flow passages in such a way that the temperature non uniformity is maintained within the desired limits. However, this can be achieved by the design of intricate and complex flow passages wherein the temperature on uniformity issue can be resolved however as the coolant passages become complex, the coolant pressure losses increase leading to high power consumption by the pump. Thus, a trade-off is to be made between the uniform heat extraction and energy consumption of the cold plate system. Also, as the flow passages become complex, the cost of manufacturing of the cold plate also increases drastically. Thus, typically several trade-offs are made in terms of design of the cold plate in terms of complexity, energy consumption and cost of manufacturing.
[006] Further when the coolant in the cold plate is replaced by a phase change material the method is known as passive cooling, since there is no active power consuming device. In passive cooling the heat transfer process mainly relies on a phase change of the material. Generally, an organic/inorganic salt are used as phase change materials, configured to extract heat from a heat source by absorbing the heat in form of latent energy. The organic/inorganic salt absorbs heat at a constant temperature and changes its phase say from liquid into gas or from solid into liquid during the phase change process. The phase change material is generally used when external power source is not available and or when the space availability is too low to accommodate the pump and fan system. However, the phase change material operates only within the specified temperature range, once the phase change process is completed, heat needs to be extracted from the phase change material so that it again comes back into the actual state.
[007] However, one of the limitations of phase change material is its low thermal conductivity. This severely slows down the heat transfer rate as the thermal resistance is high thereby leading to higher thermal response time.

OBJECTS OF THE INVENTION
[008] The principal object of the present disclosure is to provide a hybrid cold plate with combination of active and passive cooling/heating technology.
[009] Another object of the present disclosure is to provide a phase change material with high latent heat to maintain the temperature of the cold plate within the uniform range.
[0010] Yet another object of present disclosure to provide a cold plate configured to have dual cooling that is active liquid cooling/heating as well as passive cooling.

SUMMARY
[0011] In an implementation of the present disclosure a cold plate assembly 100 is disclosed. The cold plate assembly 100 further comprises, a hybrid structure. The hybrid structure further comprises an active cooling/heating apparatus. The active cooling/heating apparatus comprises a base substrate 3. Further a first connector 1 and a second connector 2 is mounted on the base substrate 3. The hybrid structure further comprises a passive active cooling/heating apparatus. The passive active cooling/heating apparatus comprises a honeycomb matrix 4. Further a phase change material (PCM) material 13 is infused within the honeycomb matrix 4.

BRIEF DESCRIPTION OF DRAWINGS
[0012] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
[0013] Figure 1, illustrates exploded view of a cold plate assembly in accordance with the exemplary embodiment.
[0014] Figure 2 illustrates a surface of the cold plate assembly in accordance with the exemplary embodiment.
[0015] Figure 2 illustrates a detailed view of the honeycomb matrix with coolant path in accordance with the exemplary embodiment.

DETAILED DESCRIPTION
[0016] Some embodiments of the present disclosure, illustrating all its features, will now be discussed in detail. It must also be noted that as used herein and in the appended claims, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary system discloses portable mini air conditioner with efficient heat exchanger.
Part List
- First Connector 1
- Second Connector 2
- Base Substrate 3
- Honeycomb Matrix 4
- Cover Plate 5
- Fluid Cover Plate 6
- Top Surface 7
- Matrix 9
- Entry Channels 10
- Intermediate Channels 11
- Exit Channels 12
- PCM material 13
- Honeycomb Matrix Side 14
[0017] In accordance with an exemplary embodiment a hybrid cold plate comprising a combination of active and passive cooling/heating system. The hybrid cold plate may comprise a fluid channel engraved within the cold plate. Further an infusion of phase change material may be embedded inside a honey comb structure. Further the honey comb structure may fit inside the cold plate. The phase change material has high latent heat thereby maintaining the temperature of the cold plate within the uniform range. The encapsulation of these phase change material within the honeycomb structure increases the thermal mass of the system. The present disclosure further enables extreme light weighting of the cold plate since the honeycomb structure within the cold plate is made of low density high thermal conductivity material and has minimum wall thickness for maximum accommodation of the PCM Material. Along with light weighting the overall structural strength of the said cold plate is enhanced due to the honeycomb matrix present inside the cold plate.
[0018] Referring to Figure 1, illustrates exploded view of a cold plate assembly in accordance with the exemplary embodiment. The cold plate assembly 100 may comprise a hybrid structure. The hybrid structure comprises an active cooling/heating apparatus and a passive active cooling/heating apparatus. The active cooling/heating apparatus comprises a base substrate 3. The base substrate 3 may be fabricated using an aluminium or other thermal conducting materials. Further the base substrate 3 may comprise a first connector 1 and a second connector 2. The first connector 1 may be configured to enable flow of a coolant fluid into a plurality of channel provided internally within the cold plate 100. Further the second connector 2 may be configured to enable the exit of the coolant fluid from the plurality of channels.
[0019] Further in accordance with the exemplary embodiment, the passive active cooling/heating apparatus may comprise of a honeycomb matrix 4 embedded into the cold plate. The honeycomb matrix 4 may be inserted onto the base substrate 3. Further a cover plate 5 may be positioned above the honeycomb matrix 4. The cover plate 5 may be provided to encapsulate the honeycomb matrix 4 between the base substrate 3 and a fluid cover plate 6. The fluid cover plate 6 may be configured to enclose the plurality of channels integrally provided within the cold plate.
[0020] Now referring to Figure 2 and Figure 3, the cold plate assembly 100, may further comprise a top surface 7. The top surface 7, may be in contact with a target body. The heat or energy flows from a surface of the target boy in contact with the top surface 7 of the cold plate assembly 100. The top surface 7 of the cold plate assembly 100 may be further in physical contact with the honeycomb matrix 4 where the heat flow is directed. Further a phase change material (PCM) material 13 infused within the honeycomb matrix 4 absorbs heat while undergoing phase change. Further the plurality of channels 10, 11, 12 may be provided along the periphery of the honeycomb matrix 4, as illustrated as entry channels 10, intermediate channels 11, and exit channels 12.
[0021] In accordance with Figure 1, Figure 2, and Figure 3, a coolant enters in the cold plate assembly 100 through the first connector 1. Further coolant flows around the periphery of PCM material 13 infused within the honeycomb matrix 4 within the plurality of channels 10, 11, 12. Further the coolant may exit from the cold plate assembly 100 through the second connector 2. The PCM material 13 may be embedded inside a hexagonal cavity resembling a shape of the honeycomb. The honeycomb matrix 4 surrounds the PCM material 13 from all side 14. The honeycomb matrix 4 is made of highly thermally conductive material typically metals like Aluminium, Copper etc. Within the matrix 9 there are numerous of these honeycomb cavities within which the PCM material 13 is embedded. Thus, the present disclosure leverages the heat absorbing capacity of the PCM material by ensuring high heat transfer rate due to high thermal conductivity offered by the Honeycomb Matrix.
[0022] In an aspect of the present disclosure the Hybrid structure comprises a mix of active cooling and passive cooling technologies. The active cooling component are preferably the coolant flow path 10,11 and 12. Further the passive cooling component is of the honeycomb matrix infused with PCM. The honeycomb matrix within the cold plate assembly, the mechanical properties of the cold plate like stiffness, torsional strength and overall structural integrate is enhanced and at the same time, its weight is drastically reduced.
[0023] Further the present disclosure provides following advantage:
- Temperature uniformity is maintained within 1 deg C across the cold plate.
- Thermal mass of the Cold Plate as a system is increased, thereby desired temperature control is maintained for a longer duration of time even after the coolant supply is cut-off by the pump.
- Intermittent supply of coolant is sufficient in accordance with the present disclosure since the PCM Material is continuously extracting heat from the target body irrespective the coolant is circulation is On or Off. This leads energy saving in the system.
- The PCM infused inside the honeycomb matrix absorbs sudden thermal shock from the target body thereby avoiding any damage to the target body due to overheating.
- The infusion of the PCM inside the Honeycomb structure inherently increases the overall thermal conductivity of the PCM system.
- The honeycomb structure has maximum surface area in contact with PCM thereby drastically enhancing the heat transfer rate through the PCM.
- The aluminum honeycomb matrix drastically enhances the structural integrity of the cold plate in terms of the shearing strength, bending strength and crushing strength.
- The PCM infused honeycomb matrix, is ultra-light, and enables an ultra-lightweight design of the cold plate.
- The coolant line along the periphery of the PCM infused Aluminum honeycomb matrix extract the heat from the PCM material thereby reconverting it to the original phase.
, Claims: We claim:

1. A cold plate assembly 100 comprises:
a hybrid structure comprising:
an active cooling/heating apparatus, and a passive cooling/heating apparatus,
wherein the active cooling/heating apparatus comprises:
a base substrate 3;
a first connector 1 and a second connector 2 mounted on the base substrate 3;
wherein the passive cooling/heating apparatus comprises:
a honeycomb matrix 4; and
a phase change material (PCM) material 13 infused within the honeycomb matrix 4.

2. The cold plate assembly 100 as claimed in claim 1, wherein the honeycomb matrix 4 is inserted onto the base substrate 3.
3. The cold plate assembly 100 as claimed in claim 1, further comprises a cover plate 5 positioned above the honeycomb matrix 4.
4. The cold plate assembly 100 as claimed in claim 3, wherein the cover plate 5 is provided to encapsulate the honeycomb matrix 4 between the base substrate 3 and a fluid cover plate 6.
5. The cold plate assembly 100 as claimed in claim 1, further comprises a plurality of channels 10, 11, 12 provided along the periphery of the honeycomb matrix 4.
6. The cold plate assembly 100 as claimed in claim 4, wherein the fluid cover plate 6 is configured to enclose the plurality of channels 10, 11, 12 integrally provided within the cold plate.
7. The cold plate assembly 100 as claimed in claim 1, further comprises a top surface 7, in contact with a target body.
8. The cold plate assembly 100 as claimed in claim 1, wherein the honeycomb matrix 4 provides enhanced stiffness and structural strength.
9. The cold plate assembly 100 as claimed in claim 1, wherein the honeycomb matrix 4 further enables reduction in weight of the cold plate assembly 100.

Dated this 26th day of October, 2023