Heat exchanger with passive in-line temperature control

Abstract

The invention describes a heat exchanger that continuously and passively regulates the transfer of heat across each part of the heat exchanger's partitions. Such partitions composed of typically two tubes, one inside the other's bore, that at various points, contact each other or separate from each other, thereby increasing or decreasing heat transfer across their walls at those points. Such separations and contacts being spontaneously effected by changes in the shape of at least one of the tubes which is driven by elements connected to that tube and which change their shape in response to temperature changes, such as shape memory alloys (SMA's) or bi-metal strips.

What is claimed is:  
     
         1 . A system that controls thermal energy from passing from one medium to another medium, comprising: 
 two or more partitions that are thermally conductive and at least one of the said partitions is connected to a container or to the end of another partition, in such a way that they in cooperation physically segregate the said media preventing them from substantially commingling with one another; and    said partitions where they are separated from each other act to significantly reduce thermal transmission between them, across the points of separation, and consequently, between said media, across those same points of separation, and    said partitions where they are contacting each other act to significantly increase thermal transmission between them across the points of contact and consequently, between the said media, across those same points of contact, and    at least one of the said partitions is flexible which simultaneously allows all or parts of its surface to contact or separate from, a corresponding part of the surface of another of the said partitions, and    at least one motive element that changes shape in response to changes in temperature, and    the said motive element is in contact with or in transmission with, and has its temperature changed by, and in relation to, the changes of temperature of the medium to which it is most proximate and does not change its shape or does less so in relation to another medium to which it is not as proximate, and    the said motive element, as its parts change shape in response to the temperature of the most proximate medium, in turn changes the shape of a flexible partition to which it is connected or a part and the change of shape can cause all or corresponding parts of the surface of the said flexible partition to contact or separate from all or corresponding parts of the surface of another of the said partitions and thereby alter the thermal transmission from one media through to the other across the parts of the partitions that are separated or in contact.    
     
     
         2 . A system that controls thermal energy from passing from one medium to another medium, comprising: 
 two or more partition tubes that line or are lined or both by at least one other partition tube, and    said partition tubes are thermally conductive and at least one of the said partition tubes is connected to a container, or to the end of another partition tube, in such a way that they in cooperation physically segregate the said media preventing them from substantially commingling with one another; and    said partition tubes where they are separated from each other act to significantly reduce thermal transmission between the said partition tubes, across the points of separation, and consequently, between said media, across those same points of separation, and    said partition tubes where they contact each other act to significantly increase thermal transmission between them, across the points of contact, and consequently, between the said media, across those same points of contact, and    at least one of the said partition tubes is flexible which allows all or a part of its surface to alternatively contact and separate from, a corresponding part of the surface of another of the said partition tubes, and    at least one motive element that changes shape in response to changes in temperature, and the said motive element is in contact with or in transmission with, and has its temperature changed by, and in relation to, the changes of temperature of the medium that it is most proximate to and does not change its shape or does less so in relation to another medium to which it is not as proximate, and    the said motive element, as it changes shape in response to the temperature of the most proximate medium, in turn changes the shape of those parts of the flexible partition tube to which it is connected or of which it is part, and    those parts of the said flexible partition tube which have their shape changed, depending upon the preferred embodiment, may contact or separate from corresponding parts of the surface of another partition tube and thereby alter the heat transmission from one media through to the other across the parts of the partition tubes that are separated or in contact.    
     
     
         3 . A system of  claim 2 , wherein a flexible partition tube  5  includes at least one bellow that allows the said flexible partition tube  5  to expand and; and in cooperation with the cross-sectional shape of any partitions it lines or is lined by, facilitates contacting and separating from any of those other partitions.  
     
     
         4 . A system of  claim 2 , wherein a flexible partition tube  5  contains features that assist in aligning the said flexible partition tube  5  with another partition tube that it immediately lines or is immediately lined by, perhaps in cooperation with some aligning features contained in the said partition tubes it immediately lines or is lined by, that facilitates the intended and substantial separation or the substantial contacting of the said flexible partition tube  5  with the said partition tubes it immediately lines or is lined by.  
     
     
         5 . A system of  claim 2 , wherein a flexible partition tube  5  contains one or more bellows  7  that assist in aligning the said flexible partition tube  5  with another partition tube that it immediately lines or is immediately lined by, perhaps in cooperation with some aligning features contained in the said partition tubes it immediately lines or is lined by, that facilitates the intended and substantial separation or the substantial contacting of the said flexible partition tube  5  with the said partition tubes it immediately lines or is lined by.  
     
     
         6 . A system of  claim 2 , wherein a flexible partition tube  5  has one or more motive elements connected to it or that are incorporated into it, that change shape in response to the temperature of the medium that is most proximate to it, and 
 that in turn change the cross-sectional shape of the flexible partition tube, and  
 thereby cause the said flexible partition tube  5  to expand and contract in a direction that causes the said flexible partition tube  5  to either contact or separate from any partition tubes it lines or is lined by.  
 
     
     
         7 . A system of  claim 2 , wherein the motive elements are made of shape memory alloy (SMA), or other shape memory material and has a memorized shape which is relaxed by the extraction of thermal energy, and is at least partly recovered with the application of thermal energy thereby causing the motive element to change shape upon the said extraction of thermal energy or by the application of thermal energy, such energy being applied or extracted by the temperature of the medium that is most proximate to it, and 
 that in turn change the shape of the flexible partition, and    thereby cause the said flexible partition tube  5  to expand and contract, in cooperation with any other spring in the said flexible partition tube, and    thereby cause the expanding or contracting flexible partition tube  5  to either contact or separate from any partition tubes it lines or is lined by.    
     
     
         8 . A system of  claim 2 , wherein the motive element is made of shape memory alloy (SMA), wherein the said motive element  9  is deformed by the spring of the flexible partition tube, normal to its longitudinal axis, from a previously memorized shape in a deformation state selected from one or more of bending, tension and torsion, and at a temperature at or above an austenite finish temperature of the SMA material such that the SMA material exhibits superelastic behavior by forming stress-induced martensite or exhibits pure elastic behavior, or some combination of both superelastic and elastic behavior in different areas or layers of the said motive element, and 
 wherein the application of thermal energy, by the temperature of the medium that is most proximate to it, causes the SMA material to increase in temperature, which causes the stiffness of the said motive element to increase and thereby attempt to resume its memorized shape  
 either by a concomitant increase in elastic modulus of the SMA material or by an increase in a value of a superelastic stress plateau, which is a stress at which the stressinduced martensite is first formed, or by a combination thereof, or other more complex deformation and recovery paths occurring as a function of stress, strain and temperature, including complex sub-loops at temperatures at or above the austenite finish temperature of the SMA material, and  
 in attempting to resume its memorized shape overcomes or partly overcomes the said deformation by the spring of the flexible partition tube; and  
 when energy is extracted from it by the temperature of the medium that is most proximate to it, causes the said motive element to relax and be partly or completely overcome by the spring of the flexible partition tube, and  
 that the said stiffness and relaxation of the said motive element acting in cooperation with the said spring of the flexible partition tube changes the cross-sectional shape of the said flexible partition tube, and  
 thereby cause the said flexible partition tube  5  to expand or contract, and  
 cause the expanding or contracting flexible partition tube  5  to either contact or separate from any partitions it lines or is lined by.  
 
     
     
         9 . The system of  claim 2 , wherein the motive element is made of bi-metal strips of metal, or other materials, that change their shape upon the said extraction of thermal energy or by the application of thermal energy, such energy being applied or extracted by the temperature of the medium that is most proximate to it, and 
 that in turn change the shape of flexible partition tube's  5 , and    thereby cause the said flexible partition tube  5  to expand or contract, in cooperation with any other spring in the flexible tube, and    thereby cause the expanding or contracting flexible partition tube  5  to either contact or separate from any partition tubes it lines or is lined by.    
     
     
         10 . The system of  claim 2 , wherein flexible partition tube  5 , can simultaneously and along different parts of its wall surface, in response to the varying temperatures of media acting on motive elements  9  and said flexible partition tube  5  adjacent to those parts, contact and separate from the immediately adjacent parts of partition tubes that the said flexible partition tube  5  lines or is lined by.  
     
     
         11 . The system of  claim 2 , wherein the flexible partition tube  5  includes means for imparting or adding flexibility to the said tube, and 
 such flexibility allows the said flexible partition tube  5  to expand and contract in directions that facilitate contacting and separating the said flexible partition tube  5  from another partition tube that it immediately lines or is immediately lined by.  
 
     
     
         12 . The system of  claim 2 , wherein the flexible partition tube  5  includes means for imparting or adding flexibility to the said tube, and 
 such flexibility allows the said flexible partition tube  5  to expand and contract in directions that facilitate contacting and separating the said flexible partition tube  5  from another partition tube that it immediately lines or is immediately lined by, and  
 those means include any number of bellows  7  that form a part of the wall of the said flexible partition tube, and run along the walls of the flexible partition tube continuously or discontinuously, straight, annularly, longitudinally, helically or along any required path.  
 
     
     
         13 . The system of  claim 2 , wherein the flexible partition tube  5  includes means for maintaining alignment with the partition tube that it immediately lines or is immediately lined by, and 
 such means includes any number of bellows  7  that form a part of the wall of the said flexible partition tube, and run along the walls of the flexible partition tube continuously or discontinuously, straight, annularly, longitudinally, helically or along any required path, and  
 such bellows  7  are shaped such that they allow the said flexible partition tube to expand and contract, and  
 such bellows  7  are shaped such that they cooperate with a T-rail  8  that is connected to or a part of the facing wall of a partition tube that the said flexible partition tube immediately lines or is immediately lined by, and  
 and said T-rails run along the walls of the flexible partition tube in a complementary manner to the said bellows  7  with which they cooperate, and  
 when the said flexible partition tube  5  lines another partition tube, to which the T-rail is connected or is a part and when the said flexible partition tube  5  contracts, the bellows  7  grasps the said T-rail  8 ; and the skirt  8   b , waste  8   c  and the bulb  8   d  of the T-rail act in concert to hold the said flexible partition tube at a proper distance from the inside walls of the partition wall to which the T-rail is connected, perhaps in concert with other bellow and T-rail combinations located around the radius of the flexible partition tube  5  and the other partition tube it lines. and 
 when the said flexible partition tube  5  lines another partition tube, to which the T-rail is connected or a part of and when the said flexible partition tube expands, the bellows  7  release the said skirt and said waste of the said T-rail  8 , but the bellows maintain contact with the head of the bulb  8   d  of the T-rail  8 , which in cooperation with perhaps one or more other sets of bellows  7  and T-rail  8  combinations, act to hold the said flexible partition tube at a proper distance from the inside of the walls of the partition wall it lines, until the said flexible partition tube is fully expanded and in some preferred embodiments fully contacts the inside of the walls of the partition tube it lines, and  
 
 when the said flexible partition tube  5  is lined by another partition tube, to which the T-rail is connected and when the said flexible partition tube expands, the bellows  7  release the skirt and waste of the said T-rail  8 , but still maintain contact with the head of the bulb  8   d , which in cooperation with perhaps another set of bellows  7  and T-rail  8 , but preferably two additional sets, evenly spaced around the perimeter of the said flexible partition tube, acts to hold the said flexible partition tube at a proper distance from the outside walls of the partition wall to which the T-rail is connected, and 
 when the said flexible partition tube  5  is lined by another partition tube, to which the T-rail is connected and when the said flexible partition tube  5  contracts, the bellows  7  grasp the skirt  8   b , waste  8   c  and bulb  8   d  of T-rail  8 , and act to hold the said flexible partition tube at the proper distance from the outside of the walls of the partition wall to which the T-rail is connected, until the said flexible partition tube is fully contracted and in some preferred embodiments fully contacts the outside walls of the partition wall to which the T-rail is connected.  
 
 
     
     
         14 . The system of  claim 2 , wherein there are pressure relief means that relieve the pressure difference hat may develop between the flexible partition tube and another partition tube that the said flexible partition tube lines or is lined by, when the said partition tube expands away from or approaches that other partition tube.  
     
     
         15 . The system of  claim 2 , wherein the space between the flexible partition tube  5  and another partition tube that the said flexible partition tube lines or is lined by, forms a vacuum when the said partition tube expands away from that other partition tube, thereby further interrupting the conduction of heat across the said space  6 .  
     
     
         16 . The system of  claim 2 , wherein pressure equalization means are included to neutralize the effect of the pressure of the medium contained in a flexible partition tube, or surrounding a flexible partition tube, on the shape of the flexible partition tube.  
     
     
         17 . The system of  claim 2 , wherein pressure equalization means are included to neutralize the effect of the pressure of the medium contained in a flexible partition tube  5 , or surrounding a flexible partition tube  5 , on the shape of the flexible partition tube, and 
 these means include a means for keeping separate the two streams of media that are separated by the partition tubes.    
     
     
         18 . The system of  claim 2 , wherein the motive element or elements are connected to various parts of the flexible partition tube to control the expansion and contraction of each part of the said flexible partition tube in response to the temperature and temperature changes in the medium most proximate to the said motive element, and 
 said motive element or elements can be continuous or discontinuous, and    the said motive element or elements can form part of the flexible partition tube  5 , be connected or attached to either side of the bellows  7  or be connected at both ends to the inside walls of the said flexible partition tube or be located at other places within or outside the said flexible partition tube  5  that change the shape of the said flexible partition tube in response to changes in temperature of the medium most proximate to it.    
     
     
         16 . The system of  claim 2 , wherein the motive element is further isolated from the thermal effects of the medium on the other side of the other thermal partition by the interposition of insulation and insulation means including flexible insulation.  
     
     
         17 . The system of  claim 2 , wherein the motive element is made more responsive to the medium in which it is most proximate, by the addition of fins and other means of increasing the surface area of the said motive element.  
     
     
         18 . The system of  claim 2 , wherein the means of aligning the flexible partition tube from other partition tubes is the inclusion of spurs on the folds in the flexible partition tube  5  proximal to the bellows, that act to align and control the separation and contacting of the flexible partition tube and the other partition tube that it immediately lines or is immediately lined by.  
     
     
         19 . The system of  claim 2 , wherein the motive element and its complementary bellows to which it is attached includes means for increasing the force and distance over which the force is applied to cause the connected bellows and groove to change shape, in response to temperature changes in the medium most proximal to the said motive element.  
     
     
         20 . The system of  claim 2 , wherein the system may include a T-rail  8 , referred to as the “dog bone” T-rail that controls the motion of two flexible partition tubes  5 ,  5   a  that have facing bellows, and how the geometry of the said dog bone T-rail can be varied to effect the functions of the partition tubes and the consequent conductivity between the media separated by the said partition tubes.  
     
     
         21 . The system of  claim 2 , wherein the relative shape of the flexible partition tube and the other partition tube that it lines or is lined by, permits the gradual contacting and separation of the partition tubes, and thereby the gradual application or extraction of heat across the partition tubes.  
     
     
         22 . The system of  claim 2 , wherein partition tubes are sectioned longitudinally to facilitate the assembly of said partition tubes around each other.  
     
     
         23 . The system of  claim 2 , wherein motive elements are snapped over partition tubes that are sectioned, longitudinally along the bellows, to hold the said sectioned tubes together, to facilitate easier assembly.  
     
     
         24 . The system of  claim 2 , wherein methods to further thermally isolate the partition tubes and the motive element by treating the facing surfaces of the partition tubes to reduce radiant and convective heat transmission.  
     
     
         25 . The system of  claim 2 , wherein the system is used to regulate the temperature of working medium or product medium and both for various purposes.  
     
     
         26 . The system of  claim 2 , wherein the system is used to regulate the temperature of working medium or product medium and both for regulating the temperature of fuel for efficient combustion, including engines and heating devices, by using waste heat from the engine or the exhaust stream or the exhaust flue.  
     
     
         27 . The system of  claim 2 , wherein the system is used to regulate the temperature of working medium or product medium and both for controlling the temperature of the cooling medium used in an engine.  
     
     
         28 . The system of  claim 2 , wherein the system is used to regulate the temperature of working medium or product medium and both for controlling the temperature of medium in a container, to prevent over-heating or under-heating of the said medium.  
     
     
         29 . The system of  claim 2 , wherein the system is used to regulate the temperature of working medium or product medium and both for heat storage, including storing heat recovered from the exhaust stream of an engine or from the engine itself during operation for later recovery, usually at cold-start up, for heating the vehicle, the engine, a catalytic converter, battery or any other device that requires heating.  
     
     
         30 . The system of  claim 2 , wherein the flexible partition tube is given a cross-sectional shape normal to its longitudinal axis that is complementary to the cross-sectional shape normal to its longitudinal axis that of another partition tube that it lines or is lined by such that when the flexible partition tube is contracted or expanded toward the said other partition tube that the two tubes have a greater surface in contact than when the said flexible partition tube is contracted or expanded away from the other partition tube, by in both cases the motive element responding to the temperature of the medium in which it is most proximate and it in turn expanding or contracting the said flexible partition tube, and 
 including the preferred embodiment where the flexible tube is approximately elliptical and the other partition tube it lines or is lined by is approximately round, or the other way around.    
     
     
         31 . The system of  claim 2 , wherein the vacuum that may develop between the flexible partition tube and another partition tube that the said flexible partition tube lines or is lined by, when the said partition tube expands away from that other partition tube is relieved by the introduction of ambient air or some other gas having a higher insulative value such as argon or carbon dioxide.  
     
     
         32 . The system of  claim 2 , wherein carbon dioxide or other gas that is a good absorber of radiant energy is circulated through the space between partition tubes, and perhaps cooled outside the system illustrated herein, to enhance the thermal isolation of the media that are separated by the thermal partitions.  
     
     
         33 . The system of  claim 2 , wherein various materials and interposed between the partition tubes that act as thermal insulators, when the said partition tubes are separated, but are relatively good thermal transmitters when the said partition tubes are in contact.  
     
     
         34 . The system of  claim 2 , wherein various surface treatments, including reflective surfaces, are applied to the facing surfaces of the said partition tubes to reduce thermal transmission by radiation between the said partition tubes and between the media they separate.  
     
     
         35 . The system of  claim 2 , wherein one or more of the said partition tubes can have closed ends.  
     
     
         36 . The system of  claim 2 , wherein means are described for making the flexible tube flexible in a direction normal as well as parallel to the said tube's axis, including bellows, that form part of the wall of the said flexible tube and that run continuously or discontinuously along the wall of the said tube in any direction including, annularly, or straight or helically along or around the longitudinal axis of the tube.  
     
     
         37 . The system of  claim 2 , that includes means to create and maintain a vacuum between the partition tubes to reduce thermal energy transfer across the said tubes.  
     
     
         38 . The system of  claim 2 , wherein the said partition tubes do either not contact or separate from each other, but rather approach or recede from each other and in so doing vary the thermal transmission between and through them and consequently between the media they separate.  
     
     
         40 . The system of  claim 1 , wherein the said partition tubes do either not contact or separate from each other, but rather approach or recede from each other and in so doing vary the thermal transmission between and through them and consequently between the media they separate.