Abstract:
Disclosed are various thermoelectric heaters. A thermal transfer component has a first plate attached to a second plate. A heating channel is formed by at least one of the first plate or the second plate of the thermal transfer component. The heating channel is between the first plate and the second plate of the thermal transfer component. A heating element is within the heating channel.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to CN Application No. 201610527750.3, filed on Jul. 1, 2016, which is incorporated by reference herein in its entirety. 
       BACKGROUND 
       [0002]    The temperature in an area or room can be raised to a more desirable level using an electrical heater. Thermal transfer can be grouped into three broad categories: conduction, convection, and radiation. Thermal conduction generally refers to transfer of thermal energy through physical contact. Thermal convection generally refers to transfer of thermal energy through heating a fluid, such as liquid or gas (e.g. air). As the air in a room is heated, the warmer air rises, displacing cooler fluid and causing the air to circulate. Thermal radiation generally refers to transfer of thermal energy using electromagnetic waves. Raising the temperature of an object can cause it to radiate infrared waves, which can come into contact with another object causing a heating effect. 
         [0003]    Some heaters, such as oil filled radiators, can cause a combination of convection heating and radiant heating to heat a room. However, using oil can cause problems in manufacture and end use. If seals fail, the oil can leak out, causing problems for the end user. Oil seals can require costly manufacturing requirements, which can be burdensome for manufacturers to implement. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0005]      FIG. 1  is a drawing of an example of a thermoelectric space heater. 
           [0006]      FIG. 2  is a drawing of an example of a thermal transfer component of the thermoelectric space heater. 
           [0007]      FIG. 3 . is a drawing of an example of an exploded view of the thermal transfer component of the thermoelectric space heater. 
           [0008]      FIG. 4  is a drawing of an example of a sectional view of the thermal transfer component of the thermoelectric space heater. 
           [0009]      FIG. 5  is a drawing of a heating element of the thermoelectric space heater. 
           [0010]      FIG. 6  is a drawing of another example of a thermal transfer component of the thermoelectric space heater. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    The present disclosure relates to thermoelectric space heaters. The heaters described herein can provide fast heating by distributing the heating element throughout the thermal transfer fin or component. This can overcome the long heating times of existing oil-filled heaters that have a heating element only across a bottom of the heater, requiring oil convection within the heater to distribute heating. The thermoelectric space heaters described can heat at nominal power for long durations, without causing the outer edges to go over safe operating temperatures (e.g., 85° C.). The design of the heating element and its arrangement in a channel of the thermoelectric space heater can allay the danger of causing scorching or burning. Also, a tip-over switch may not be needed, for example, by using lower resistance per unit length for the heating element in a lower temperature region and a higher resistance per unit length heating element for a higher temperature region in a heating channel. The structure of the thermoelectric space heaters described in the present disclosure is robust, has few parts, assembles conveniently, and has low production cost. 
         [0012]    Referring now to the figures,  FIG. 1  shows an example of a thermoelectric space heater  100 . The thermoelectric space heater  100  has a number of thermal fins or thermal transfer components  106 A- 106 G (individually, “thermal transfer component  106 ,” collectively, “thermal transfer components  106 ”). The thermal transfer components  106  can be connected to each other using convex protrusions  109 A and  109 B (collectively, “convex protrusions  109 ”). The convex protrusions  109  can provide a spacing distance between thermal transfer components  106  of the thermoelectric space heater  100 , as well as an interconnection thoroughfare  112 . The spacing between the thermal transfer components  106  can allow for efficient heating and convection of the air around the thermal transfer components  106  to heat an area. The interconnection thoroughfare  112  can be used to contain the electrical connections to each of the heating elements of the thermal transfer components  106 . For example, the heating elements can be connected by an electrical circuit board, pinboard, or wires within the interconnection thoroughfares  112 . In some cases an electronic control module can be included for the thermoelectric space heater  100  in the interconnection thoroughfare  112 , for example, on a circuit board or a pinboard for connecting the heating elements. A tip-over switch can be included in the electronic control module to prevent dangerous conditions when the thermoelectric space heater  100  tips over. In other embodiments, the thermal transfer components and other parts of the thermoelectric heater  100  can be designed such to prevent dangerous conditions even when the thermoelectric space heater  100  tips over. For example, the temperature of the exterior portions of the thermoelectric space heater  100 , like the outer edges of the thermal transfer components  106 , can be designed to stay below a specified temperature. 
         [0013]    The thermal transfer components  106  can have the convex protrusions  109  on one or both sides (e.g. left and right sides as shown) of the thermal transfer components  106 . For example, a first thermal transfer component  106  can be substantially flat on one side, and can still be connected to the next thermal transfer component  106  while maintaining the spacing distance by convex protrusions  109  on the next thermal transfer component  106 . 
         [0014]    The thermal transfer components  106  shown in  FIG. 1  each have two convex protrusions on each side. The convex protrusions of the thermal transfer components  106  can be connected to each other, and in some examples the connection can be facilitated by screws or rivets or a weld such as a rolling weld. In other examples, a thermal transfer component  106  can have additional, fewer, or no convex protrusions  109 , and the thermal transfer components  106  can be connected in another manner, for example, using bars or bolts. Where no convex protrusions  109  are used, an interconnection thoroughfare  112  can be provided by a tube or conduit that connects the thermal transfer components  106 , or by a base or a top of the thermoelectric space heater  100 . 
         [0015]    In some situations, the inner thermal transfer components  106  (e.g.  106 B- 106 F) can be different from the outer thermal transfer components  106  (e.g.  106 A and  106 G). For instance, in some cases, the thermal transfer component  106 A can be made without convex protrusions  109  on one or both sides. Additionally, the heating elements for the outer thermal transfer components  106  can differ from the inner thermal transfer components  106 , as will be discussed further below. For example, the outer thermal transfer components  106  can be made to stay below a certain maximum temperature delta between the ambient temperature and the end temperature (e.g., 85° C.). In some examples, an outer thermal transfer component  106  can be covered by a control panel. 
         [0016]    Moving now to  FIG. 2 , shown is a drawing of an example of a front view of one side of a thermal transfer component  106  of the thermoelectric space heater  100 . The thermal transfer component  106  can have a heating channel  133 , an insulating channel  136 , and insulating holes  139 . The thermal transfer component  106  can be said to have a heating area  142  and an insulating area  145 . The heating area  142  refers to a center portion of the surface area of each of the plates of the thermal transfer component  106 , and the insulating area  145  refers to the periphery of the surface area of each of the plates of the thermal transfer component  106  around the heating area  142 . 
         [0017]    The heating channel  133  is in the heating area  142  and can be used to contain a heating element of the thermoelectric space heater  100 . In some situations a thermal transfer component  106  can have multiple channels  133  for multiple heating elements, and in other situations a single heating channel  133  can be used. The heating channel  133  can be designed to cover a surface area of the thermal transfer component  106 . To this end, the heating channel  133  can have a number of curves, and can meander or snake along a height and a width of the thermal transfer component  106  within the heating area  142 . The heating channel  133  can have one or both ends opening into one or both of the interconnection thoroughfares  112 . As shown in  FIG. 2 , the heating channel  133  has both ends opening into the bottom interconnection thoroughfare  112 . In this way, electrical connections to a heating element in the heating channel  133  can be made in the interconnection thoroughfare  112 . In some examples, a single heating element can run the entire length of the heating channel  112 . When the convex protrusions  109  are in the heating area  142  as shown, they can become heated. Adjacent convex protrusions  109  of adjacent thermal transfer components  106  can be connected. The connection can provide for heat transfer or conduction between the thermal transfer components  106 . In other embodiments, the heating channel  133  can have one end connecting to the bottom interconnection thoroughfare  112  and another end connecting to the top interconnection thoroughfare  112 . The thermal transfer component  106  can also have more than one heating channel  133 . The form of the heating channel  133  can improve mechanical strength of the thermal transfer component  106 . 
         [0018]    The insulating channel  136  can be in the insulating area  145  of the thermal transfer component  106 . The insulating channel  136  can provide a measure of thermal isolation for an outer edge of the thermal transfer component  106  from the heating channel  133  of the heating area  142 . In this way, the outer edge of the thermal transfer component  106  can be cooler than the heating channel  133 . The insulating channel  136  can be substantially along the outer edge of the thermal transfer component  106 . In some situations the insulating channel  136  can itself compose the outer edge of the thermal transfer component  106 , and in other cases, the thermal transfer component  106  can have a flat outer edge extending beyond the insulating channel  136 . In other words, the thermal transfer component  106  can have an insulating channel  136  along an outer edge of the thermal transfer component  106  and can have a fin composing the outer edge of the thermal transfer component. In some cases, the insulating channel  136  can contain insulation or an insulating material, and in other cases, the insulating channel  136  can be empty. The insulating material can be cotton. 
         [0019]    The thermal transfer component  106  can further have insulating holes  139  in the insulating area  145 . The insulating holes  139  can provide a measure of thermal isolation between areas of the thermal transfer component  106  by limiting thermal conduction between areas. For example, the insulating holes  139  can provide thermal isolation between the area of the heating channel  133  and the outer edge of the thermal transfer component  106 . The insulating holes  139  can be any shape, including circular, clover-shaped, or kidney-shaped as shown, or can be square, rectangular, ovular, or have another shape. The insulating holes  139  can be stamped in a plate of the thermal transfer component  106  and can be alignment holes, such as rivet holes, or holes with ridges for connecting plates of the thermal transfer component  106  together as will be discussed below. While the insulating holes  139  can be anywhere in the thermal transfer component  106 , the insulating holes can be in a fin composing the outer edge of the thermal transfer component  106 , and can be used along with, or in lieu of, the insulating channel  136 . The insulating holes  139  can also provide for cross-ventilation between the thermal transfer components  106  of the thermoelectric space heater  100 . 
         [0020]      FIG. 3  shows an example of an exploded view of the thermal transfer component  106 . The thermal transfer component  106  can have a plate  160  and a plate  161  that form or compose an exterior of the thermal transfer component  106 . The thermal transfer component  106  can also have a heating element  163 , and can further have a sheet  166  and a sheet  169 . When assembled, the plate  160  and the plate  161  can be connected using rivets, screws, welds, a rolling weld, or another manner. 
         [0021]    The heating element  163  can be a flexible electrical wire or cord, and in some examples, can be insulated. In other situations, the heating element  163  can be a rigid heating element. The heating element  163  can be between the sheets  166  and  169 . In some examples, the sheets  166  and  169  can be metal foil sheets such as aluminum or tin foil. Where the heating element  163  is flexible, the sheets  166  and  169  can serve to hold the heating element in a particular arrangement or shape. To this end, the sheets  166  and  169  can be formed with a recess or indent with the shape of the heating channel  133 , and can be used to hold the heating element  163  in place during manufacture or assembly of the thermal transfer component  106  while positioning the heating element  163  in the heating channel  133 . In addition, when assembled in the thermal transfer component  106 , the sheets  166  and  169  can help with conduction or other transfer of heat from the heating element  163  to the thermal transfer component  106 , while preventing direct contact between the heating element  163  and the thermal transfer component  106 , which can prevent damage or influence to the thermal efficiency of the heating element  163 . The sheets  166  and  169  can prevent the heating element  163  from coming out of the heating channel  133  and increase ease of assembly and manufacturing efficiency. In some examples, the heating element  163  can be assembled in the heating channel  133  without the sheets  166  and  169 . 
         [0022]    Looking back to  FIG. 1 , where a thermoelectric space heater  100  has multiple thermal transfer components  106 , each with a heating element  163 , the heating elements  163  can be connected using a circuit board, a pinboard or wiring in the interconnection thoroughfare  112 . The heating elements  163  can be connected in series or parallel. In other examples there can be a single heating element  163  that goes through all of the thermal transfer components  106 , connected through the interconnection thoroughfare  112 . 
         [0023]    With reference to  FIG. 4 , shown is an example of a sectional view of the thermal transfer component  106 , and a zoomed view of a portion of the thermal transfer component  106 . The sectional view of  FIG. 4  can correspond to section A-A of the thermal transfer component  106  indicated in  FIG. 2 . The sectional view of the thermal transfer component  106  shows the plate  160  and the plate  161  of the thermal transfer component  106 . The thermal transfer component  106  can have the insulating channel  136 , the heating channel  133 , the insulating holes  139 , and the convex protrusions  109 . Here, the plate  160  and the plate  161  each have a convex protrusion  109 . In other embodiments, only one (or neither) of the plates of the thermal transfer component  106  can have the convex protrusion  109 . 
         [0024]    The heating channel  133  can be formed between the plates  160  and  161 . Each of the plates  160  and  161  can have an indent that forms the heating channel  133 . In other embodiments, only one of the plates  160  or  161  has an indent, and the other plate can be flat, while still forming the heating channel  133  between the plates  160  and  161  when assembled. The heating element  163  can be within the heating channel  133  as shown. 
         [0025]    In some aspects like the heating channel  133 , the insulating channel  136  can be formed between the plates  160  and  161 . Each of the plates  160  and  161  can have an indent that forms the insulating channel  136 . In other embodiments, only one of the plates  160  or  161  has an indent, and the other plate can be flat, while still forming the insulating channel  136  between the plates  160  and  161  when assembled. 
         [0026]    The insulating holes  139  are also shown in the sectional view. This view illustrates that the insulating holes  139  can be holes through both of the plates  160  and  161 . The insulating holes  139  can be stamped in the plates  160  and  161  of the thermal transfer component  106 . The insulating holes  139  can also be rivet holes. In other examples, the insulating holes  139  can be alignment holes that aid the connection of the plate  160  to the plate  161 , using a ridge, or curl as shown. In some instances the ridge or curl of the insulating hole  139  through the plate  160  can be larger than the ridge or curl of the same insulating hole  139  through the plate  161 . In other instances only one of the plates can have the ridge or curl. The outer edge of the thermal transfer component  106  is also shown to have a ridge or curl to connect the plates  160  and  161 . In other words, one or both of the plates  160  and  161  can form ridges or curls that facilitate a connection of the plate  160  to the plate  161 , both along the outer edge of the thermal transfer component  106  and along edges of the insulating holes  139 . 
         [0027]    The zoomed-in region shows the heating element  163  within the heating channel  133 . In the zoomed view, the sheets  166  and  169  can be seen sandwiched around the heating element  163 , between the plates  160  and  161 . While the heating elements  163  is within the heating channel  163 , the sheets  166  and  169  are between the plates  160  and  161  both inside the heating channel  163  as well as sandwiched between the plates  160  and  161  outside of the heating channel  163 . The heating element  163  is located substantially at the center of the heating channel  133  such that there is an air gap or space between the heating element  163  and the heating channel  133 . This can prevent temperature imbalances from one side to another side of the thermal transfer component  106 , and can prevent the temperature from becoming too high as a result of direct contact. 
         [0028]    Moving to  FIG. 5 , shown is a cut-away drawing of an example of a section of the heating element  163 . The heating element  163  can have an inner core  182 , a resistive heating wire  184 , and an outer insulation layer  186 . As mentioned earlier, the heating element  163  can be relatively flexible or can be rigid. The resistive heating wire  184  can be wrapped around the inner core  182  of the heating element  163 . Voltage or current applied to the resistive heating wire  184  can cause the resistive heating wire to produce heat. To this end, the resistive heating wire  184  can be wrapped around the inner core  182  with a desired wrapping density in order to produce a desired heating level for the section of the heating element  163  as a result of the resistance per unit length of the resistive heating wire wrapped around the inner core  182 . In some examples, the desired wrapping density, and changes in wrapping density, can be achieved by wrapping the resistive heating wire  184  wrapped around the inner core  182  in a spiral winding pattern. In other embodiments, the winding pattern can achieve the desired wrapping density and variations using a square pattern, a pattern of connected loops, or another pattern. 
         [0029]    In some situations, the entire heating element  163  has a single desired resistance per unit length of the heating element  163 . In that case, the heating element  163  can have a restive heating wire  184  wrapped at a substantially constant wrapping density around the inner core  182  for the entire length of the heating element  163 , the constant wrapping density causing the heating element to have the single desired resistance per unit length. In other situations, the heating element  163  can have different desired resistance per unit length for different sections along the length of the heating element  163 , to create different heating levels in different locations of the heating element  163 . One way to achieve this is to wrap the resistive heating wire  184  with a variable wrapping density, with a higher wrapping density where more heat or more resistance per unit length is desired and a lower wrapping density where less heat or less resistance per unit length is desired. In this way, a single heating element can be used for the entire length of a heating channel while, and the single heating element in the heating channel can provide one or more different heating levels with the single heating element. 
         [0030]    The heating element  163  shown in  FIG. 5  has a different wrapping density in different areas along its length. While the heating element  163  can be oriented in any way, and can be curved or meandered when assembled, the terms top and bottom are used with specific reference to the orientation of the section of the heating element  163  shown in  FIG. 5 . The top of the heating element  163  shows the resistive heating wire  184  wrapped around the inner core  182  at different wrapping density than the bottom of the heating element  163 . The wrapping density corresponds to the distance that can be measured between the wraps of the resistive heating wire  184  on one side of the inner core  182 , where a lower wrapping density corresponds to greater distance and higher wrapping density corresponds to lesser distance. The distance d 1  between the spiral structure of the resistive heating wire  184  wrapped around the inner core  182  at the top of the heating element  163  indicates one wrapping density while the distance d 2  at the bottom of the heating element  163  indicates another wrapping density in that location. Because d 1  is greater than d 2 , the top of the heating element  163  (corresponding to d 1 ) has a lower wrapping density, and a lesser resistance per unit length, than the bottom of the heating element  163  (corresponding to d 2 ). Generally, lower wrapping density corresponds to a lower heating level, or less heat produced per unit length of the heating element  163 . The heating element  163  can be designed, along with the heating channel  133 , the insulating holes  139 , insulating channels  136  or other components of the thermoelectric space heater  100 , such that the does not need over-temperature electrical controls or a tip-over sensor. In other cases, over-temperature electrical control or a tip-over sensor can nevertheless be utilized. 
         [0031]      FIG. 6  shows an example of another thermal transfer component  106  that illustrates how different heating regions  191  and  192  of a heating channel can have different heating levels. For example, the heating element  163  can have different resistance per unit length in the region  191  compared to the region  192 . In this example, the heating level in the center of the thermal transfer component  106  can be designed to be higher than the periphery. To this end, the region  191  can indicate where the heating element  163  has a higher resistance per unit length, for example by having a higher wrapping density. The region  192  can indicate where the heating element  163  has a lower resistance per unit length, for example by having a lower wrapping density. In this way, the thermal transfer component  106  can produce more heat in the center, which can be transferred to the air by convection, while the outside edge of the thermal transfer component  106  is cooler to the touch. 
         [0032]    As shown, the heating element  163  can start with a first wrapping density in region  191  within the heating channel  133 , change to another wrapping density in region  192 , and then transition back to the first wrapping density. While two regions  191  and  192  are shown, additional regions can be designed, and the wrapping density or resistance per unit length can be abruptly or gradually transitioned along the length of the heating element  163 . In some examples, additional heating elements can be used, each with constant or varied resistance per unit length. 
         [0033]    Referring back to  FIG. 1 , the outer thermal transfer components  106  can be designed to have a different heating level than the inner thermal transfer components. In some cases, government, industry, or other regulations can require that a limited temperature that is allowed for the outermost edges of a heater (e.g., 85° C.), while the inner areas can have greater temperatures. For example, the thermal transfer component  106 A can have a lower resistance per unit area than the thermal transfer component  106 B for the respective heating elements in the respective heating channels. Further, each thermal transfer component  106  of the thermoelectric space heater  100  can be designed with its own respective heating element, causing its own set of heating regions as discussed. 
         [0034]    It is emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations described for a clear understanding of the principles of the disclosure. Many variations and modifications can be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure.