09/994,580, entitled,"FLUID HEAT EXCHANGER ASSEMBLY AND PERSONAL COOLING DEVICE", filed on November 27, 2001.

BACKGROUND 1. Field of the Invention [0002] The present invention relates to a fluid heat exchanger assembly and more particularly to a personal cooling device. The invention utilizes commercially available thermoelectric heat transfer devices having the capability to concurrently provide heating and cooling on opposing sides of the device.

2. Description of the Related Art <BR> <BR> [0003] The heating and/or cooling of fluid (i. e. , gases or liquids) in transmit or at a point of accumulation has been effected in a multitude of fashions dating back as far as the origin of the very reasons for such heat transfer. A majority of the pieces of prior art typically center around heat transfer from or to a fluid by the circulation of currents from one region to another.

[0004] In the area of vehicle racing in particular, special suits are used by individuals in an attempt to maintain a cooler epidermal temperature while performing various strenuous or dangerous acts. One such product, in particular, the K&P Temp Suit, is a hooded vest made from a loose-knit cotton fabric with a nylon inner liner worn by a driver while competing in an automobile race. The system is supplied with the suit, an ice with chest with a pump, a timer, fittings, wire connecters and enough hose and wires to mount the components almost anywhere in the vehicle. The cooling system, in particular, consists of either a 16-quart or 8- quart ice chest with a built-in pump and attached hose. The manufacturer of this device indicates that using the 16-quart chest the ice load will last up to four hours depending upon the cooling line insulation, test location and heat load. Temperature control is accomplished by a variable timer. This timer cycles the pump on and off at various rates thereby controlling the temperature. The suit, in particular, has a chin strap which keeps a cooling tube against the back of the neck thereby cooling the back of the neck. The chin strap and the vest front are fastened by velcro, thereby making fastening or unfastening simple. The suit is connected to the cooling system by a quick release or dry brake connecter.

[0005] Other designs of racing suits have centered around various forms of fabric which are considered to"breath. "These fabrics allow water vapor emitted from the epidermal layer to pass through the fabric thereby taking heat from the epidermal layer to the environment.

Additionally, body-suits worn by those involved in hazardous activities typically provide regions or layers which are impervious to air flow for various safety reasons. However, these safety reasons often conflict with the ability of the wearer to stay relatively cool in performing their duties by inhibiting air flow for cooling the epidermal region of the wearer, thus generally inhibiting the stamina of the wearer. These systems have compromised the cooling capabilities of various fabrics directly to inhibit the very air flow which could present a danger to the wearer. Other body-suits have been developed in which cool liquids are circulated throughout a particular apparel, only to be refrigerated and reticulated again.

[0006] Additionally, racing helmets for stock car drivers have been fitted with built-in side ports to accommodate air conditioning hoses or ventilation hoses. An example of such a ventilation hose attachment may be seen on NASCAR Winston Cup type vehicles where a duct is placed in the driver's window opening, which is cupped inward toward the driver, pulling air into an attached ventilation hose which flows into a side port on the driver's helmet. Additionally, these helmets have various vents which can be opened to provide variable flow, thus directing the air flow to a particular region (s) that the driver desires.

Helmets worn by open wheel racers or motorcycle racers, in general, typically have vents which can be opened in a variable fashion or completely closed thereby directing airflow into the helmet in various orientations. These helmets need not use the duct and ventilation hose used by stock car drivers, because in large part their helmet is directly in the line of fluid or air flow over the cockpit.

SUMMARY [0007] The present invention relates to a heat transfer system for cooling fluids utilizing one or more thermoelectric devices being made up of two ceramic wafers and a series of P and N doped semi-conductor blocks positioned there between. The ceramic wafered thermoelectric devices are used to cool a conduit (s) through which the fluid is passed. Effective heat transfer is brought about when the fluid moves through the conduit enabling conduction between the ceramic wafered thermoelectric device and the particles of the conduit.

[0008] Advantageously, the ceramic wafered thermoelectric devices operate on relatively low power and voltages and are relatively durable. Because the ceramic wafered thermoelectric devices emanate thermal energy on the side of the devices opposite that of the cooling side, the exemplary embodiment of the present invention may utilize a plurality of conduits for fluid flow enabling the heat withdrawn from a first conduit to be distributed to at least a second conduit.

[0009] It is a first aspect of the present invention to provide a fluid heat exchanger assembly comprising: a fluid inlet; a cooler fluid conduit in fluid communication with the fluid inlet having a cooler fluid outlet; a warmer fluid conduit in fluid communication with the fluid inlet and having a warmer fluid outlet; and at least one ceramic wafered thermoelectric device having a cooling wafer surface and an opposed warming wafer surface, positioned between the warmer fluid conduit and the cooler fluid conduit, such that the cooling wafer surface faces the cooler fluid conduit and the warming wafer surface faces the warmer fluid conduit; where upon electrical activation of the ceramic wafered thermoelectric device the cooling wafer becomes relatively cool in comparison to the warming wafer surface becoming relatively warm.

[0010] It is a second aspect of the present invention to provide a method of exchanging heat between at least two fluid conduits comprising the steps of : providing at least one ceramic wafered thermoelectric device having at least a cooling wafer surface and a warming wafer surface opposing the cooling wafer surface; and positioning the ceramic wafered thermoelectric device to develop a thermal gradient between fluid within a conduit to be cooled and the cooling wafer surface of the ceramic wafered thermoelectric device, and to develop a thermal gradient between fluid within a conduit to be heated and the warming wafer surface of the ceramic wafered thermoelectric device.

[0011] It is a third aspect of the present invention to provide a fluid heat exchanging assembly comprising: a fluid inlet; a cooler fluid conduit in fluid communication with the fluid inlet and splitting into at least two parallel conduits between the fluid inlet and at least one cooler fluid outlet; at least one warmer fluid conduit in fluid communication with the fluid inlet; at least two ceramic wafered thermoelectric devices each having a cooling wafer surface opposing a warming wafer surface, a first one of the ceramic wafered thermoelectric wafer devices being positioned between the warmer fluid conduit and a first one of the parallel conduits, such that the cooling wafer surface faces the first one of the parallel conduits and the warming wafer surface faces a section of the warmer fluid conduit, the second ceramic wafered thermoelectric device being positioned between the warmer fluid conduit and a second one of the parallel conduits such that the cooling wafer surface faces the second one of the parallel conduits and the warming wafer surface faces a section of the warmer fluid conduit; a power source operatively coupled to the ceramic wafered thermoelectric device; and a warmer fluid outlet in fluid communication with the warmer fluid conduit.

[0012] It is a fourth aspect of the present invention to provide a fluid heat exchanging assembly comprising: a fluid inlet; a warmer fluid conduit in fluid communication with the fluid inlet and splitting into at least two parallel conduits between the fluid inlet and at least one warmer fluid outlet; at least one cooler fluid conduit in fluid communication with the fluid inlet; at least two ceramic wafered thermoelectric devices each having a cooling wafer surface opposing a warming wafer surface, the first one of the ceramic wafered thermoelectric devices being positioned between the cooler fluid conduit and a first one of the parallel conduits such that the warming wafer surface faces the first one of the parallel conduits and the cooling wafer surface faces a section of the cooler fluid conduit, the second ceramic wafered thermoelectric device being positioned between the cooler fluid conduit and a second one of the parallel conduits such that the warming wafer surface faces the second one of the parallel conduits and the cooling wafer surface faces a section of the cooler fluid conduit; a power source operatively coupled to the ceramic wafered thermoelectric device; and a cooler fluid outlet in fluid communication with the cooler fluid conduit.

[0013] It is a fifth aspect of the present invention to provide a method of cooling the epidermis of a human being comprising the steps of : providing at least one ceramic wafered thermoelectric device having at least a cooling wafer surface and an opposed warming wafer surface; developing a thermal gradient between the fluid to be cooled and the cooling wafer surface of the ceramic wafered thermoelectric device by the ceramic wafered thermoelectric device; and directing the cooled fluid through a region in fluid communication with the epidermis of a human being.

[0014] It is a sixth aspect of the present invention to provide a method for protecting the epidermis of a human being comprising the steps of : providing at least one ceramic wafered thermoelectric device having at least a cooling wafer surface and an opposed warming wafer surface; developing a thermal gradient between the fluid to be cooled and the cooling wafer surface of the ceramic wafered thermoelectric device by the ceramic wafered thermoelectric device; directing the cooled fluid to a region approximate the epidermis of a human being; and selectively dispersing a combustion suppression fluid in place of, or in combination with, the cooled fluid when conditions for combustion are present or are detected.

[0015] It is a seventh aspect of the present invention to provide a method of cooling the epidermis of a human being comprising the steps of providing at least one ceramic wafered thermoelectric device having at least a cooling wafer surface and an opposed warming wafer surface; utilizing the ceramic wafered thermoelectric device to develop a thermal gradient between the fluid to be cooled and the cooling wafer surface of the ceramic wafered thermoelectric device; donning hazardous duty apparel by a human being, the apparel having a plurality of conduits for cooling fluid flow; and directing the cooled fluid to the plurality of conduits in the apparel.

[0016] It is an eighth aspect of the present invention to provide a personal cooling device for use with hazardous duty equipment and/or apparel (such as racing equipment and/or apparel), comprising: an air conduit having an inlet and an outlet, the outlet being in fluid communication with an item of racing apparel, an item of hazardous duty apparel, a protective helmet, a harness, a belt, a shoe, a sock, a glove, and/or a body suit; and at least one ceramic wafered thermoelectric device having a warming wafer surface opposing a cooling wafer surface, positioned in close proximity to the air conduit and such that the cooling wafer surface faces the air conduit so as to allow heat transfer between the air conduit and the cooling wafer surface.

[0017] It is a ninth aspect of the present invention to provide a personal cooling system for a racecar driver, comprising: a protective helmet having at least one coolant air path extending therein in fluid communication with an inlet; an air intake mounted to the racecar adapted to receive at least a portion of air flowing past the racecar; a coolant conduit coupled between, and providing fluid communication between the inlet of the protective helmet and the air intake; at least one ceramic wafered thermoelectric device having a warming wafer surface opposing a cooling wafer surface, positioned in close proximity to the coolant conduit and oriented such that the cooling wafer faces the coolant conduit; and a power supply operatively coupled to the ceramic wafered thermoelectric device, whereby the ceramic wafered thermoelectric device promotes heat transfer between the coolant conduit and the cooling wafer surface.

BRIEF DESCRIPTION OF THE DRAWINGS [0018] Fig. 1 is a perspective view of an exemplary fluid heat exchanger apparatus according to certain aspects of the present invention; [0019) Fig. 2 is a cross-sectional view of the fluid heat exchanger apparatus of Fig. 1, taken along lines 2-2 of Fig. 1 ; [0020] Fig. 3 is a perspective view of an optional blower for use with the fluid heat exchanger apparatus of Fig. 1; [0021] Fig. 4 is a schematic representation of a cooled racing jumpsuit for use with the fluid heat exchanger apparatus of Fig. 1 ; [0022] Fig. 5 is a perspective view of a 3-way valve assembly coupled between the fluid heat exchanger apparatus, the cooled jumpsuit and a source of flame suppression fluid; and [0023] Fig. 6 is a schematic representation of a cooled racing helmet assembly utilizing a fluid heat exchanger apparatus according to an aspect of the present invention.

DETAILED DESCRIPTION [0024] A method and apparatus for heating and/or cooling fluids in transit is disclosed. More particularly, a personal cooling device for use with hazardous duty equipment or apparel, or for use with racing equipment or apparel is disclosed. In the following description, for purposes of explanation, specific references are set forth to provide a thorough understanding of exemplary embodiments of the present invention. However, those of ordinary skill in the art will understand these detailed explanations to be non-limiting and encompassing obvious variations of the detailed description.

[0025] The ceramic wafered thermoelectric devices (CWTD) utilize two thin ceramic wafers with a series of bismuth telluride semi-conductor blocks sandwiched therebetween which are sufficiently doped to exhibit an excess of electrons (P) or a deficiency of electrons (N). The ceramic wafer material provides an electrically-insulated and mechanically rigid support structure for the thermoelectric device. The"P & N"type semiconductor blocks are electrically interconnected such that, upon electrical activation and depending upon the polarity, heat is transferred from one ceramic wafer to the opposite wafer causing a first ceramic wafer to become cooled while the opposing ceramic wafer becomes hot. The CWTDs are commercially available, for example, as the ZMAX line from Tellurex Corporation, Traverse City, MI (www. tellurex. com).

[0026] The structure of an exemplary embodiment of the present invention may be assembled utilizing 1.5 inch aluminum tubing, 0.375 inch polymer tubing, two ceramic wafered thermoelectric devices having wafer surface area approximately measuring 2.25 inches squared, and two aluminum conduits for distributing the fluid flow between the sections of 0.375 inch polymer tubing.

[0027] As shown in Figs. 1 and 2, an exemplary embodiment of a fluid heat exchanger assembly 10 for use with the present invention includes a primary fluid conduit 12 having a fluid inlet 14 and a fluid outlet 16, and a secondary fluid conduit 18 having a fluid inlet 20 and a fluid outlet 22. In this exemplary embodiment, the secondary fluid conduit 18 branches from, and is in fluid communication with, the primary fluid conduit at a point 24 upstream from a heat exchange section 26 such that fluid flowing into the inlet 14 of the primary fluid conduit 12 will flow into the fluid inlet 20 of the secondary fluid conduit 18. At a point 24 upstream from the heat exchanger section 26, the secondary fluid conduit 18 branches into a pair of parallel (in a flow sense), conduit branches 28A and 28B, each of which are coupled to a respective pair of heat exchange conduits 30A and 30B.

[0028] Each heat exchange conduit 30A, 30B is a fluid conduit of heat transfer material, such as aluminum, having an inlet 32A, 32B, an outlet 34A, 34B and a substantially planar heat exchange segment 36A, 36B positioned therebetween. Each heat exchange conduit 30A, 30B is positioned on opposite radial sides of the primary fluid conduit 12 in the heat exchange section 26, and each sandwiches a ceramic wafered thermoelectric device 38 therebetween.

As discussed above, each CWTD 38 includes a ceramic wafer 40A, 40B that becomes relatively hot and a ceramic wafer 42A, 42B that becomes relatively cool when power is supplied to the leads 44 of the CWTD 38. A power source (not shown) provides 12VDC to the leads 44 when activated. In the present exemplary embodiment, the hot wafer 40A, 40B faces the primary fluid conduit 12 and the cool wafer 42A, 42B faces the heat exchange segment 36A, 36B of the heat exchange conduit 30 in fluid communication with the secondary fluid conduit 18. In the exemplary embodiment, the heat exchange segment 36A, 36B of the heat exchange conduit 30A, 30B is divided into a plurality of discrete paths 46A, 46B to increase surface area contact between the heat exchange material of the heat exchange conduit 30A, 30B and the fluid flowing therethrough (See Fig. 2 in particular).

[0029] As power is delivered to the CWTDs 38 by leads 44, the hot ceramic wafer 40A, 40B becomes relatively hot by drawing the thermal energy away from cold ceramic wafer 42A, 42B and the thermal energy generated by the semiconductors as a result of current flow therethrough. The difference in temperature between the hot ceramic wafer 40A, 40B and the temperature of the fluid within the primary fluid conduit 12 establishes a gradient for thermal energy transfer to the fluid in the primary fluid conduit from the hot ceramic wafer 40A, 40B.

Concurrently, the cold ceramic wafer 42A, 42B becomes relatively cold as thermal energy is drawn away from its surface. The difference in temperature between the cold ceramic wafer 42A, 42B and the fluid within heat exchange conduit 30A, 30B establishes a gradient for thermal energy transfer from the fluid flowing within heat exchange conduit 30A, 30B to the cold ceramic wafer 42A, 42B. In sum, the result is fluid passing within primary fluid conduit 12 being heated or increased in temperature by operation of the CWTDs 38; and, simultaneously, the fluid passing within secondary fluid conduit 18 is cooled or decreased in temperature by operation of the CWTDs 38.

[0030] After the fluid within primary fluid conduit 12 has passed through the heat exchange section 26, the warmer fluid is expelled via the fluid outlet 16. Concurrently, cooler fluid within secondary fluid conduit 18, after having passed through the heat exchange section 26, is thereafter expelled via the fluid outlet 22.

[0031] As will be described in a first exemplary application of this heat exchanger assembly 10, the fluid outlet 22 from the secondary fluid conduit 18 provides a source of cooled air to an apparel item of a race-car driver and the fluid outlet 16 from the primary fluid conduit 12 is in fluid communication with an exhaust port or channel.

[0032] If the orientation of the CWTDs 38 are switched, or if the polarity of the power supplied to the leads 44 of the CWTDs 38 were reversed, then the fluid flowing through the primary fluid conduit 12 would be cooled and the fluid flowing through the secondary fluid conduit 18 would be heated. Thus, as will be described below in a second exemplary application of this heat exchanger assembly 10, the CWTDs 38 are reversed as described, the fluid outlet 16 from the primary fluid conduit 12 provides a source of cooled air to a helmet of a race-car driver and the fluid outlet 22 from the secondary fluid conduit 18 is in fluid communication with an exhaust port or channel.

[0033] As shown in Fig. 3, it is within the scope of the present invention to utilize a fluid pump, such as a blower 48, to accelerate the fluids flowing through the primary and/or secondary conduits 12,18. The blower 48 of Fig. 3 is coupled in fluid communication with the primary conduit 12, upstream from the heat exchange section 26, by a fluid conduit 50 that branches from the primary fluid conduit 12. As the blower 48 operates, fluid is drawn from the environment into the blower 48 and pushed through the branch conduit 50, thereafter arriving in primary fluid conduit 12. The fluid flow generated by blower 48 results in a decrease in fluid pressure in the inlet 14 upstream from primary conduit 12. This decrease in pressure results in a pressure differential between the fluid source and fluid at the entrance of the inlet 14, thus inducing fluid flow into the inlet 14 and directionally toward primary fluid conduit 12. It is within the scope of the present invention to provide a pump with more than one fluid outlet, or provide a plurality of pumps with one or more fluid outlets for generating flow in the direction of the primary conduit 12. It is within the scope of this aspect of the present invention that the blower 48 be substituted with any type of pump which can create a pressure differential in the fluid, thereby promoting fluid flow in a desired direction. Examples of pumps which may be used with the present invention include, without limitation, fans, positive displacement pumps, gear pumps and centrifugal pumps.

[0034] As shown in Fig. 4, a first exemplary application for the fluid heat exchanger assembly 10 is to cool a jumpsuit 52 worn by a race-car driver. The jumpsuit 52 includes a plurality of conduits 54 extending into various regions of the jumpsuit 52, where the conduits 54 include air exit ports 56 that allow cool air to be released in the respective region of the jumpsuit 52. Each of the conduits 54 are coupled for fluid communication with an inlet conduit 57 that, in turn, includes a quick-disconnect coupling 58 for providing fluid communication with a source of cooled air, such as the fluid outlet 22 of the fluid heat exchanger assembly 10.

[0035] The plurality of conduits 54 are a structure of flexible hoses divided into five sections for total body cooling. The sections are: left front lower conduit 54A, right front lower conduit 54B, right front upper conduit 54C, left front upper conduit 54D and a conduit 54E for the neck and/or head cooling, or for leading to the rear of the jumpsuit 52. Inlet conduit 57 may be secured to the jumpsuit (Kevlar Safety Suit) 52. The user may additionally have a mechanism (not shown) conveniently placed in relation to the position of the user's appendages thereby enabling the user to provide restriction of the fluid flow if the desired cooling effect is being or has been achieved.

[0036] In addition to the jumpsuit 52, it is also within the scope of the present invention to provide conduits for fluid flow within a protective harness, a belt, a shoe, a sock, a glove, hazardous duty apparel (such as firefighting apparel) and/or racing apparel.

[0037] As shown in Fig. 5, a three-way valve 60 may be provided in fluid communication between the source of cooled air 62, a source of combustion suppression fluid 64 and a fluid outlet 65, which includes a quick-disconnect coupling 66 adapted to mate with the quick- disconnect coupling of the jumpsuit 52. The source of cooled air 62 may be the fluid outlet 22 of the fluid heat exchanger assembly 10. The three-way valve 60 may be operated in such a manner so as to selectively provide fluid communication between the fluid outlet 65 and the source of the cooled air 62 to the exclusion of combustion suppression source 64, or to selectively provide fluid communication between the fluid outlet 65 and the combustion suppression source 64 to the exclusion of the source of cooled air 62. The three-way valve 60 may be electrically connected via leads 68 to a power source (not shown) in which case the user may utilize a manual switch 70 or an automatic switch (not shown) to option between the fluid communication possibilities offered.

[0038] The combustion suppression source 64 may be continuously in fluid communication with a combustion suppression hose 72. Combustion suppression fluid may be any available combustion suppression agent having as a suppression ingredient fluid or solid matter disbursed utilizing a fluid medium. Examples of such suppression ingredients include water, carbon dioxide, sand and dry powders.

[0039] As shown in Fig. 6, a second exemplary application for the fluid heat exchanger assembly 10 is to provide cooling air to a racer's helmet 74. In this application, the polarity of the CWTDs 38 are reversed so that the air in the primary conduit 12 is cooled and the air in the secondary conduit 18 is heated. A duct 76, positioned at the inlet 14 of the primary conduit 12, may be mounted, for example, in a driver's door window opening in the lower corner closest to the front of the vehicle to receive air flowing thereover. As the velocity of the air passing by the duct 76 increases, more and more air is drawn into the duct 76, and, in turn, the inlet 14. The duct 76 may be cupped in shape to induce air to be drawn into the duct 76 and thereby push air into primary conduit 12. At the cupped based of duct 76, an interface 78 is formed between primary conduit 12 and duct 76. The interface 78 is the point at which the air becomes axially surrounded by primary conduit 12. The continual flow of air into the duct 76 provides the driving force to move the air from the duct 76 into primary conduit 12.

Commercially available ducts can be ordered as part number FA-NACA from helmetcity. com.

[0040] The helmet 74 includes a built in side helmet port 80 for mating with the outlet 16 of the primary conduit 12. The side helmet port 80 is in fluid communication with an inner conduit or bladder 82 for distributing the cooled air about and/or onto the wearer's head. The construction of such an inner bladder 82 or conduit will be readily ascertained by those of ordinary skill in the art. The fluid outlet 18, in this application, is coupled to an exhaust port or conduit (not shown) for removing the heated air.

[0041] While exemplary applications for the fluid heat exchanger assembly 10 utilize cooled fluid expelled within a hazardous duty/racing suit or helmet, it is also within the scope of the present invention to provide a similar apparatus which expels heated fluid in situations in which such heated fluid is desired by the user in either a suit or helmet.

[0042] With each of the embodiments disclosed herein, it is within the scope of the invention to incorporate a feedback control system with power supplied to the CWTDs 38 for regulating the temperature of the fluid being heated or cooled. Such a control system would be easily available to one of ordinary skill in the art.

[0043] Following from the above description and invention summaries, it should be apparent to those of ordinary skill in the art that, while the processes and systems herein described constitute exemplary embodiments of the present invention, it is understood that the inventions contained herein are not limited to these precise processes and systems and that changes may be made to them without departing from the scope of the inventions as defined by the claims.

[0044] Additionally, it is to be understood that the invention is defined by the claims and it is not intended that any limitations or elements describing the exemplary embodiments set forth herein are to be incorporated into the meanings of the claims unless such limitations or elements are explicitly listed in the claims. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the inventions disclosed herein in order to fall within the scope of any claims, since the invention is defined by the claims and since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.

[0045] What is claimed is: