Dual Heat Pipe Thermoelectric Cooler

Abstract

Cooling sub-assemblies with thermoelectric element(s), coupling clamps, hot side and cold side heat exchanger having a direct insertion or removal of cooling modules onto a fixed mounting frame arranged in rows and columns to produce desired and required cooling levels.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent Application No. 62/339,341, filed May 20, 2016, entitled Enhanced Thermoelectric Cooling with Heat Pipes and/or Pyrolytic Graphite Film and U.S. Provisional Patent Application No. 62/396,404, filed Sep. 19, 2016, entitled Construction of a Thin-Flat Heat Pipe Air Conditioner, the disclosure of which is incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The invention relates to a dual heat pipe thermoelectric cooler using preassembled modules.

b) Description of the Related Art

Individual heat transfer of cooling modules as known in the art do not produce enough cooling for many industrial applications so that grouping is required. Direct assembly of individual parts would work but is inefficient and costly. Direct vertical insertion into a mounting frame is not an option because the need for sealing and very close spacing of the individual modules. The present invention described herein, uses pre-assembled cooling modules populated onto a single mounting platform (frame) in an inventive form.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a method and device for thermoelectric cooling, which overcomes the above-mentioned and other disadvantages of the heretofore-known devices and methods of this general type and which provides for an improvement over the prior art and solves both the problem of removing heat from a sealed contained space.

Although the invention is illustrated and described herein as embodied in dual heat pipe thermoelectric cooler, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic front view of a partial assembly hot side 13 inch by 13 inch mounting frame.

FIG. 1B is a view of a four module 13 inch by 13 inch mounting frame.

FIG. 1C is a view of the slot profile.

FIG. 2 is a side view of the construction of a thermoelectric enclosure cooler using an array of prefabricated thermoelectric cooling modules showing two modules.

FIG. 3 is a comparison chart showing the improved thermal performance with new heat-pipe modules of the present invention.

FIG. 4 is a view of the new slot detail for fin improvement to enhance interface heat transfer.

FIG. 5A shows various heat pipe construction styles.

FIG. 5B shows a flattened dual round heat pipe style.

FIG. 6A shows a thermoelectric clamp set having to clamp plates; and

FIG. 6B shows a side view and a front view of heat pipe configurations mounted on an angle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawing in detail, and first, particularly to FIGS. 1A, 1B, 1C and 2.

The present invention discloses using individual cooling sub-assemblies with thermoelectric element(s), coupling clamps, hot side and cold side heat exchanger (referred as thermoelectric cooling modules or module). The present invention pertains to direct insertion or removal of cooling modules onto a fixed mounting frame 20, a standard size is 13 inches by 13 inches. This mounting frame 20 is arranged in rows and columns to produce desired and required cooling levels. The thermoelectric cooling modules of the present invention have been manufactured tested and produce 80 watts (273 btu) or more of cooling.

The mounting frame 20 shown in FIG. 1A shows a prototype design having four (4) cooling modules on an industry standard 13×13 inch frame with space for up to six (6) modules. The frame mounting 20 as shown in FIG. 1B has a large opening 22 in the center of the frame 20 that provides space for an electronic AC to DC (alternating current to direct current) converter or power supply 32 and provides a sealed opening to load or remove modules (for service). Individual thermoelectric cooling modules 30 can be lowered into the opening 22 and inserted into slots 24 (see FIG. 1C) having rubber seals 24s to assure leak free operation.

FIG. 2 shows the construction of a thermoelectric enclosure cooler assembly 10 using an array of prefabricated thermoelectric cooling modules 30. FIG. 2 is a side view of the enclosure to be cooled 40, shown with two thermoelectric cooling modules 30, including part locations and air flow patterns. The enclosure to be cooled includes one or more heat generating components 15 such as electronic circuitry. The assembly 10 has both the waste or hot side 34 of the assembly 10 and the cold side 36 which is totally separate and isolated by the base plate or mounting frame 20 and supplemental insulation (not shown) at the power supply 32 and the around the clamping sections. In use, the entire cooler assembly 10 is mounted onto the outside of a sealed enclosure 40 to be cooled through a sealed gasket using mechanical fasteners. There are two thermoelectric modules 30 visible but the device has four (4) as seen in FIG. 1A. Other configurations can carry many other modules to produce desired cooling levels. The cooler assembly 10 outer portion is external of the enclosure 40 and includes the waste heat elements 35 of each of the thermoelectric modules 30. An inner portion of the cooler assembly 10 is disposed inside the enclosure 40 and transfers air which is cooled by respective cooling elements of each of the thermoelectric cooling modules 30 and circulates air using fans 50 into the sealed enclosure 40 and back returning through vents top and bottom. The thermoelectric cooling modules have heat pipes 52, which pass through slots 24 in the mounting frame 20. The slots 24 are provided with seals 24s that seal the periphery of the heat pipes 52. As seen in FIG. 1C, the slots 24 accommodate the seals 24s (only a portion of which is schematically shown in FIG. 1C). The ac to dc converter power supply 32 uses mains power and generates direct current to activate the thermoelectric modules and fans. Heat produced by the power supply 32 is designed to be expelled to the waste side along with the extracted heat, to maintain cooler efficiency.

FIG. 3 is a chart that shows projected performance of the new thermoelectric cooler module 30 compared to an existing industrial product manufactured by EIC Solutions, Inc., Warminster, Pa., USA, Model no. AAC-141 having 4 cooling modules. As tested the present invention provides 2 times improvement and with 6 modules provides 3 times cooling over the referenced commercial product No. AAC-141 within the same 13×13 inch mounting plate format.

It has been found that the fins 60 of the present invention as shown in FIG. 4 includes manufacturing imperfections and applicant found that small imperfections along the long slot shear line 69 flanges 65 and tends to separate the entire fin slot 67 from the heat exchanger heat pipe 52 (not shown in this FIG. 4). The new design divides the long shear line into multiple smaller segments of the flanges 65 and thereby promotes substantially better thermal contact since imperfection only affects a single section.

FIGS. 5A and 5B show several alternate configurations for heat pipes 52. FIG. 5A shows both an extruded heat pipe 52 using straight and u-shape elements for use with a dual path thermoelectric element, using a U-shape heat pipe that will reduce manufacturing costs with fewer components. The heat pipes have a crimpled seal 52s. FIG. 5B shows a design using a round but flattened U-shaped pipe using water as the working fluid. This configuration can only be used on the heat exchanger on the hot or waste side of the cooling unit. The advantage of this configuration is use of water within the heat pipes is not position sensitive, and works irrespective of the angle.

FIG. 6A shows a thermoelectric clamp set 70 with the development of thermal access ports 72 to allow thermocouples or other temperature measuring devices to monitor cooling performance and/or control signals for safety or control purposes, i.e. overheating shutoff signals, calibration or in process testing among others. The ports 72 allow access to the inner portions so that accurate measurements are possible. Thermal samples at locations on the outside will not react as quickly or provide the required critical positional thermal feedback.

Applicant has found, that as shown in FIG. 6B, some of the heat pipe configurations perform best when mounted on angle above horizontal. It has been found experimentally that the new heat pipe performs best at an angle of approximately six (6) degrees above horizontal. FIG. 6B shows a tilt bracket 74 to achieve this angle. The bracket 74 is made from a thin gage stainless steel that has very low thermal conductivity. Cross sections are kept long and is constructed and mounted in a way to isolate heat migration from the waste side 35 of the thermoelectric interface to the mounting plate 20. This improvement has shown to reduce parasitic losses.

101 is a 13×13 inch mounting frame.

103 are clamps and mounting angles strips 16 pc.

105 are fins.

107 are fans 90/120 mm mounted on cover.

109 are slots, detail in FIG. 1-c.

111 are four module 13×13 inch mounting frame.

113 is a panel hole layout.

115 is an insert individual modules, from inside, 4×8 inch cut out and cover plate for power supply module.

Alpha is 3.605 space for two fin 3.60 fin sets.

117 is an Acme U channel #CAU05 in here—allow 0.097 heat pipe snug fit.

119 is a slot profile and panel cut out area.

a is 2.500

b is 0.097

c is 1.800

121 is a rubber seal slot.

123 is an insert pipe set here.

125 is an enclosure air return.

127 is an ambient air in.

129 is a cold air out.

131 is waste hot air out.

133 is a mounting frame.

135 is one of N layers.

137 is an alternative to straight heat pipe for hot side.

139 is a straight design—cold side only.

141 is flattened to give broader contact with TEC module.

143 is a half clamp dual heat pie increases cooling.

145 is the clamp part A.

147 is the clamp part B.

149 are multiple thermal test and calibration ports.

151 are thermal barrier rings to reduce thermal loss.

153 is the TEC

155 is the cold side

157 is the hot side

Claims

1. A thermoelectric cooling system comprising:

a thermoelectric module;

said thermoelectric module sandwiched between heat pipes,

at least one of said heat pipes is an extruded microchannel heat pipe having a plurality of individual channels.

2. The thermoelectric cooling system set forth in claim 1, wherein said heat pipe arrangement is tilted.

3. The thermoelectric cooling system set forth in claim 1, wherein said extruded microchannel heat pipe contains individual channels that wick fluid against gravity.

4. The thermoelectric cooling system set forth in claim 1, wherein said heat pipes contain acetone.

5. The thermoelectric cooling system set forth in claim 1, wherein said heat pipe is tilted greater than five degrees and preferably 6 degrees.