Abstract:
A method of controlling a heat transfer apparatus comprising the steps of: providing a heat transfer apparatus; providing a control apparatus comprising a thermal sensor configured to control operation of the heat transfer apparatus; providing a casing comprising a casing wall enclosing a casing chamber, a casing entrance, and a casing seal; and inserting the thermal sensor into the casing chamber through the casing entrance an aperture in the casing seal.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a method and system for controlling a heat transfer apparatus and, more particularly, to an a method and system for increasing the operational efficiency of the heat transfer apparatus. 
       BACKGROUND OF THE INVENTION 
       [0002]    Since the early 1800s, first generation refrigeration systems have accomplished heat exchange via a vapor compressor controlled by a thermostat receiving air temperature data from inside the refrigeration cabinet via a thermal sensor. This is problematic because the ultimate goal of the refrigeration system is to maintain product temperature, and air temperature fluctuates much more rapidly than product temperature, thus creating creating premature compressor starts and stops. These premature compressor starts and stops create unnecessarily high fluctuations in product temperature, increase mechanical shock on the system, and create significant energy waste. 
       SUMMARY OF THE INVENTION 
       [0003]    According to one embodiment of the present invention, there is a method of controlling a heat transfer apparatus comprising the steps of: providing a heat transfer apparatus; providing a control apparatus comprising a thermal sensor configured to control operation of the heat transfer apparatus; providing a casing comprising a casing wall enclosing a casing chamber, a casing entrance, and a casing seal; inserting the thermal sensor into the casing chamber through the casing entrance and an aperture in the casing seal. 
         [0004]    In one aspect, the casing is configured to cause the air temperature in the casing chamber to substantially mimic a product temperature. In another aspect, the casing seal is configured to substantially prevent air from flowing into the casing chamber. In another aspect, the aperture in the casing seal is stretchable so that the casing seal is configured to receive a first thermal sensor of a first diameter at a first time and a second thermal sensor of a second diameter different than the first diameter at a second time. In another aspect, the casing wall comprises a casing seat having an inside dimension greater then an inside dimension of the casing chamber, and wherein the casing seal is seated in the casing seat. In another aspect, the casing comprises a fluid chamber enclosed between an inner casing wall and an outer casing wall. In another aspect, the casing wall is further configured to have a substantially uniform thickness. In another aspect, the casing further comprises a casing cap configured to prevent the casing seal from becoming dislodged during thermal sensor extraction. 
         [0005]    In another aspect, the method further comprises removing the thermal sensor through the aperture in the casing seal; inserting a second thermal sensor through the aperture in the casing seal; wherein the casing seal retains its ability to substantially prevent air flow through the aperture of the casing seal. In another aspect, the fluid chamber is further configured to comprise a fluid that is configured to cause the air temperature in the casing chamber to substantially mimic a product temperature. 
         [0006]    In another embodiment of the present invention, there is a system for transferring heat, comprising: a casing wall enclosing a casing chamber that is closed at one end; a casing entrance at another end of the casing; a casing cap removably connected to the casing wall at the casing entrance; and a casing seal connected between the casing cap and the casing wall at the casing entrance, the casing seal comprising a compressible material and an aperture passing through the compressible material. 
         [0007]    In another aspect, the system further comprises a casing comprising a casing seat having an inside dimension greater than an inside dimension of the casing chamber, and wherein the casing seal is seated in the casing seat. In another aspect, the system further comprises a thermal sensor located inside the casing and connected to a thermal sensor connection passing through the aperture in the casing seal, wherein the casing seal is configured to substantially prevent the flow of air through the aperture of the casing seal. In another aspect, the system further comprises a control apparatus connected to and configured to receive information from the thermal sensor via the thermal sensor connection. In another aspect, the system further comprises a heat transfer apparatus connected to and configured to be controlled by the control apparatus based at least in part on the temperature information. In another aspect of the system, the casing wall comprises plastic having a thickness of between approximately 1 mm and 15 mm. In another aspect of the system, the thermal sensor is substantially not in contact with the casing wall. In another aspect of the system, the casing seal comprises a silicone foam. In another aspect, the silicone foam is further configured to be a closed-cell silicone foam. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which: 
           [0009]      FIG. 1  is a diagrammatic view of a heat transfer apparatus with thermal sensor inserted into a casing; 
           [0010]      FIG. 2  is a perspective view of a casing according to one embodiment of the present invention; 
           [0011]      FIG. 3  is a side view of a casing according to one embodiment of the present invention; 
           [0012]      FIG. 4  is a perspective view of a casing according to another embodiment of the present invention; and 
           [0013]      FIG. 5  is a side view of a casing according to another embodiment of the present invention. 
       
    
    
       [0014]    For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures. 
       DETAILED DESCRIPTION 
       [0015]    In the following description, the use of “a,” “an,” or “the” can refer to the plural. All examples given are for clarification only and are not intended to limit the scope of the invention. 
         [0016]      FIG. 1  is a diagrammatic view of a heat transfer apparatus  10  controlled by a control apparatus  20  comprising a thermal sensor  30 . The heat transfer apparatus  10  may comprise any device or system known in the art for moving or transferring heat, including but not limited to a refrigerator, air conditioner, freezer, heat pump, etc. In the embodiment described herein, heat transfer apparatus  10  may comprise a refrigerator having, for example, an enclosed fluid conduit, a working medium within the conduit, a fluid pump, a condenser, and an evaporator. Control apparatus  20  may comprise any device, system, processor, or computer that is known in the art and is configured, through any means known (such as via mechanical components, electrical components, hydraulics, pneumatics, etc.), to control a heat transfer apparatus  10 . In the embodiment described herein, control apparatus  20  may comprise a mechanical or electronic thermostat electronically connected to the heat transfer apparatus  10 . Thermal sensor  30  may comprise any device or apparatus configured to sense heat and/or temperature that is known in the art. For example, thermal sensor  30  may comprise thermal sensor connection  140  further comprising a mechanical copper bulb sensing element connected to the control apparatus  20  via a capillary tube. Thermal sensor  30  may also comprise a thermal sensor connection  140  further comprising a digital sensing element connected to the control apparatus  20  via electrical wire. 
         [0017]    In this view in  FIG. 1 , the thermal sensor  30  has been inserted into a casing  40  through a casing entrance  70  which may create a product temperature simulating thermal barrier around the thermal sensor  30  that simulates or substantially matches a temperature of a product whose temperature aims to be sensed by the thermal sensor  30 . The casing  40  may be configured to comply with industry standards for mimicking product temperature, such as the NSF P235 protocol. 
         [0018]    In one embodiment, the present invention may comprise machine-readable instructions located on a storage medium and configured to interface with the control apparatus  20  and to receiving air temperature data from the thermal sensor  30 . The machine-readable instructions may be configured to analyze air temperature data according to a moving average algorithm configured to simulate or substantially match a temperature of a product whose temperature aims to be sensed by the thermal sensor  30  and to calculate a simulated product temperature. The control apparatus  20  comprising the machine-readable instructions may then be configured to control the heat transfer apparatus  10  according to the simulated product temperature. 
         [0019]    Referring now to  FIGS. 2 and 3 , casing  40  comprises a casing entrance  70 , a casing wall  50 , a casing seal  80 , a casing cap  90  and a casing chamber  60 . In one embodiment, the casing seal  80  is seated against a casing seat  100  to prevent the casing seal  80  from being pushed into the casing chamber  60  during insertion of the thermal sensor  30 . Likewise, the casing cap  90  may also be designed to prevent the casing seal  80  from being dislodged during extraction of the thermal sensor  30 . 
         [0020]    Casing wall  50  may have an approximately cylindrical shape with one open end and one closed end (which may be rounded), although it is not limited to this shape, and could instead having any other shape, such as an extruded square, rectangle, oval, etc. The casing wall  50  may be shaped and configured to receive and accommodate the thermal sensor  30  inside casing chamber  60 . The casing wall  50  may have a thickness of between approximately 1 mm and 15 mm, which may or may not be substantially uniform. For instance, the casing wall  50  may have a thickness near the casing entrance  70  that is greater or less than a thickness opposite the casing entrance  70 . In one embodiment, the casing  40  is configured such that the thermal sensor  30  is substantially not in contact with the casing wall  50 . 
         [0021]    The casing seal  80  may be made from any number of compressible materials designed to accommodate a thermal sensor  30  and substantially prevent airflow into the casing chamber  60  by creating a seal around the thermal sensor connection  140 . In one embodiment, the casing seal  80  is made of closed-cell silicone foam with a central aperture to allow insertion of the thermal sensor  30 . In another embodiment, the casing seal  80  is stretchable so that the casing seal  80  is configured to receive a first thermal sensor  30  of a first diameter at a first time and a second thermal sensor  30  of a second diameter different than the first diameter at a second time, without losing its ability to prevent substantially all air flow from passing through the aperture of the casing seal  80 . 
         [0022]    Casing seat  100  may comprise a groove or cut-out in the casing wall  50  that has a dimension larger than an inside dimension of the casing wall  50  and a dimension smaller than an outside dimension of the casing wall  50 , so that a thickness of material surrounding the casing seat  100  is less than a thickness of the casing wall  50 , such as between 0.5 mm and 7 mm. Casing seat  100  has an inside dimension approximately equal to an outside dimension of casing seal  80 , discussed as follows, so that casing seal  80  can rest inside and seal off the casing chamber  60  without being able to slide beyond casing seat  100 . In one embodiment, the casing seal  80  may be configured to have a slightly larger dimension which may create a more effective seal against the thermal sensor connection  140 . 
         [0023]    The casing wall  50  may comprise any rigid solid that can contain the thermal sensor  30  as well as conduct heat to and from the casing chamber  60 , such as (but not limited to), plastic, metal, ceramics, and composite materials. The casing wall  50  has one purpose of transferring heat sufficiently slowly that the air inside casing chamber  60  has a temperature representing a moving average of the temperature in the substance or environment whose temperature is being probed. In other words, the casing wall  50  may damp sharp fluctuations in the environmental temperature, so that the control apparatus  20  does not over react to changes in the environmental temperature. One aspect of the present invention includes providing different materials, dimensions, and wall thicknesses of casing wall  50  so as to achieve the desired response time between environmental temperature and temperature sensed by the thermal sensor  30 . 
         [0024]    In one embodiment, the casing wall  50  is configured to allow the air inside the casing chamber  60  to substantially mimic product temperature. The casing wall  50  may be made from a number of materials, but preferably an impact-resistant plastic that is configured to be safe for use near food. 
         [0025]    The casing chamber  60  and casing entrance  70  may be of any diameter and length configured to allow a thermal sensor  30  to be housed in the casing chamber  60 , such as at least approximately 5 mm in diameter and approximately 60 mm in length to accommodate a digital thermal sensor  30 , and at least approximately 10 mm in diameter and approximately 90 mm in length to accommodate a mechanical thermal sensor  30 . The length of the casing chamber  60  may be configured to In one embodiment, the casing wall  50  and casing seal  80  may be configured to create a substantially uniform thermal barrier around the thermal sensor  30 , which may ensure that the air temperature inside the casing chamber  60  is not asymmetrically influenced by the ambient temperature. 
         [0026]    Referring now to  FIGS. 4 and 5 , casing  40  comprises a casing entrance  70 , an inner casing wall  120 , an outer casing wall  130 , a casing seal  80 , a casing cap  90 , a casing chamber  60 , and a fluid chamber  110 . Fluid chamber  110  may be configured to hold a variety of fluids which may be configured to simulate or substantially match a temperature of a product whose temperature aims to be sensed by the thermal sensor  30 . 
         [0027]    Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
         [0028]    Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.