Patent Publication Number: US-2010107663-A1

Title: Automatic control system for combustion unit of refrigerator

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an automatic control system for a combustion gas refrigerator, and especially to an automatic control system for a combustion unit of a combustion gas refrigerator. 
     2. Description of the Prior Art 
     Refrigerators available in the markets presently mostly are electric refrigerators driven by electric power, such electric refrigerators will not work when they are put in a district having no electric power or in the field, thereby a kind of combustion gas refrigerator has been developed for the markets; a combustion gas refrigerator is provided with a cooling unit and a combustion unit, the cooling unit uses ammonia as a refrigerating agent refrigerating by absorbing and diffusing without supplying with electric power, and only is driven by heat generated by the combustion unit; this solves the trouble that electric refrigerators do not work in a district having no electric power. 
     A combustion gas refrigerator gets the effect of cooling mainly by changing over between gas state ammonia and liquid state ammonia by the physical and chemical functions to exchange heat with the outside environment, the heat required for changing over between gas and liquid phases can be provided by using various combustion material, such as gas, natural gas, kerosene, coal balls or remained heat of a stove, thereby the gas refrigerator can run without supplying electric power. 
     A conventional cooling unit and a conventional combustion unit of a gas refrigerator generally are provided at the rear of the refrigerator, when one needs to know the state of running of the refrigerator, he shall observe the burning state of the combustion unit through an observation hole, and thereby is very inconvenient; and one can only control fire power of the conventional gas refrigerator and to do ignition by a manual operation mode, this is too very inconvenient; a bottle neck thereby has been formed for popularizing of gas refrigerators in the markets. 
     There have been control devices for gas refrigerators developed and provided for markets to eliminate the defects of the manual operation mode to ignite a gas refrigerator, they include adjusting valves, pulse igniting devices and electromagnetic valves; an adjusting valve can adjust combustion gas flow, an electromagnetic valve can control blocking/opening of a combustion gas passage, a pulse igniting device is composed of a high voltage coil and an ignition induction needle provided at a combustion gas output port, the induction needle can create high voltage electric discharging at the combustion gas output port. 
     Although a control device as mentioned above for a gas refrigerator can make ignition according to the amount of combustion gas flow needed to be adjusted and can save the necessity of doing ignition by a manual operation mode, a device for igniting and fire power controlling are provided at the rear of the refrigerator, one still needs to observe the sensed high temperature in burning of the combustion unit through an observation hole at the rear of the refrigerator for adjusting the combustion gas, and this can only be done according to experience in adjusting the amount of combustion gas flow rather than according to automatic control when being at the set temperature for the inside of the refrigerator. Hence such a control device still is quite inconvenient. 
     In view of this, the inventor of the present invention studied and invented an automatic control system for a combustion gas refrigerator, the system can automatically control a combustion unit without the necessity of observing the sensed high temperature in burning of the combustion unit and adjusting the combustion gas flow by a manual operation mode, and thereby use of the system is convenient and highly safe. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide an automatic control system for a combustion gas refrigerator, the system can automatically control a combustion unit without the necessity of observing the sensed high temperature in burning of the combustion unit and adjusting the combustion gas flow by a manual operation mode, and thereby use of the system is convenient and highly safe. 
     In order to get the above stated object, the automatic control system for a combustion gas refrigerator the present invention comprises a control module, a temperature sensing device and a thermoelectric couple, the gas refrigerator is provided at its rear with a combustion unit and a cooling unit, the combustion unit is provided with a combustion gas passage in connecting with a combustion gas bottle, and is provided with an electric power supply for supplying electric power required for firing combustion gas by a pulse igniting device for burning, in order that the cooling unit can be driven by heat energy from burning, thus the gas refrigerator can keep its low temperature. 
     Wherein: the control module further includes a control circuit and an electromagnetic valve provided in the combustion gas passage, the control circuit is connected with the electromagnetic valve and a pulse igniting device to control the electromagnetic valve to block or let go of combustion gas from/for entering the combustion unit, and to control the pulse igniting device in high voltage electric discharging and igniting the combustion gas when the electromagnetic valve let go of combustion gas. 
     The temperature sensing device is provided in the gas refrigerator to sense the inside temperature of the refrigerator and to transmit a temperature signal sensed to the control circuit; if the temperature inside the gas refrigerator does not reach a set temperature value, the control circuit activates the electromagnetic valve and the pulse igniting device to ignite the combustion gas, when the temperature inside the gas refrigerator reaches the set temperature value, the control circuit shuts the electromagnetic valve to block the combustion gas from entering the combustion unit to stop burning of the latter. 
     The thermoelectric couple provided in the combustion unit is used to transmit burning signals to the control circuit, when the electromagnetic valve is in the state of letting go of the combustion gas while the flame in the combustion unit extinguishes, the thermoelectric couple will transmit an extinguishing lower temperature signal meaning abnormal burning back to the control circuit, the control circuit can thus judge to be a state of insufficiency of combustion gas or circuit abnormality, and then makes the electromagnetic valve block the combustion gas from entering the combustion unit. After the circuit equipment is examined and repaired or has its combustion bottle changed, the control module is reactivated to activate the electromagnetic valve and the pulse igniting device to reignite the combustion gas, thus an object of safe control is achieved. 
     As compared with the prior art, the present invention can automatically control the combustion unit to drive operation of the cooling unit in pursuance of the temperature inside of the gas refrigerator by means of the temperature sensing device, the thermoelectric couple and the control module, and can make re-ignition with a set time period against abnormal flame extinguishing, and can stop supplying of combustion gas with a set time period, thereby the present invention can get the effect of convenience and safety in use. 
     The present invention will be apparent in its technical measures after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective schematic view showing the structure of the present invention; 
         FIG. 2  is a schematic view showing the systematic skeleton of the present invention; 
         FIG. 3  is a perspective view of an embodiment of the present invention provided with a wind shield; 
         FIG. 4  is a perspective view of an embodiment of the present invention provided with an electric power line and an electric heating pipe. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring firstly to  FIGS. 1 and 2 , in the automatic control system for a combustion gas refrigerator  10  of the present invention, the combustion gas refrigerator  10  is provided at its rear with a combustion unit  11  and a cooling unit  12 , the combustion unit  11  is provided with a combustion gas passage in connecting with a combustion gas bottle, and is provided with an electric power supply  13  for supplying electric power required for firing combustion gas by a pulse igniting device  14  for burning; the cooling unit  12  can be driven by heat obtained by burning of the combustion unit  11 , in order that the gas refrigerator  10  can keep a low temperature. The automatic control system comprises a control module  20 , a temperature sensing device  30  and a thermoelectric couple  40 . 
     Wherein: the control module  20  further includes a control circuit  21  and a normally closed type electromagnetic valve  22  provided in the combustion gas passage, the control circuit  21  is connected with the electromagnetic valve  22  and the pulse igniting device  14  to control the electromagnetic valve  22  to block or let go of combustion gas from/for entering the combustion unit  11 , and to control the pulse igniting device  14  in high voltage electric discharging and igniting the combustion gas to render the combustion unit  11  to start burning when the electromagnetic valve  22  let go of combustion gas. 
     The temperature sensing device  30  is provided in the gas refrigerator  10  to sense the inside temperature of the refrigerator  10  and to transmit a temperature signal sensed to the control circuit  21 ; if the temperature inside the gas refrigerator  10  does not reach a set temperature value, the control circuit  21  activates the electromagnetic valve  22  and the pulse igniting device  14  to ignite the combustion gas, heat energy generated by burning of the combustion unit  11  drives the cooling unit  12  to operate, so that the temperature inside the gas refrigerator  10  is lowered; when the temperature inside the gas refrigerator  10  reaches the set temperature value, the control circuit  21  shuts the electromagnetic valve  22  to block the combustion gas from entering the combustion unit to stop burning of the latter. 
     The thermoelectric couple  40  provided in the combustion unit  11  is used to transmit burning signals to the control circuit  21 , when the electromagnetic valve  22  is in the state of letting go of the combustion gas while the flame in the combustion unit  11  extinguishes, the thermoelectric couple  40  is unable to transmit burning signals back to the control circuit  21 , then the control circuit  21  makes the pulse igniting device  14  discharge and ignite to fire the combustion gas, thus an effect of automatically restarting igniting can be obtained. 
     If the thermoelectric couple  40  is unable to transmit burning signals back to the control circuit  21  in a predetermined time after the pulse igniting device  14  restarts igniting, the control circuit  21  can judge to be a state of insufficiency of combustion gas or circuit abnormality, and then makes the electromagnetic valve  22  block the combustion gas from entering the combustion unit  11 . After the circuit equipment is examined and repaired or has its combustion bottle changed, the control module  20  is reactivated to activate the electromagnetic valve  22  and the pulse igniting device  14  to reignite the combustion gas, thus an object of safe control is achieved. 
     As shown in  FIGS. 2 and 3 , when in practicing, for avoiding accident flame extinguishing by wind blowing, a wind shield  50  of heat durable glass material can be provided on the exterior side of the combustion unit  11 . Additionally, the above mentioned electric power supply  13  can be a battery  131  or can be composed of a solar energy plate  132  and a storage battery  133 , the solar energy plate  132  can be provided on an outer wall of the wind shield  50  for storing the light energy generated from burning, and is provided in front of the gas refrigerator  10  with an indicating lamp  15  that is directly connected with the solar energy plate  132 ; when the combustion gas burns, the solar energy plate  132  not only can convert the light energy into electric energy for storing in the storage battery  133 , but also can turn on the indicating lamp  15 , in favor of observing whether the combustion gas is in the state of normally burning. 
     Moreover, the electric power supply  13  can be connected with an illumination lamp  60 , and the gas refrigerator  10  is provided on its door with a door controlling switch  61  to turn on the circuit between the illumination lamp  60  and the electric power supply  13 , in order that when the door of the gas refrigerator  10  is opened, the door controlling switch  61  turns on the circuit to make the illumination lamp  60  illuminate the gas refrigerator  10 ; while when the door of the gas refrigerator  10  is closed, the door controlling switch  61  turns off the circuit to make the illumination lamp  60  extinguish. 
     As shown in  FIG. 4 , by virtue that the cooling unit  12  of the present invention is driven by heat for running, the gas refrigerator  10  can not only make the cooling unit  12  operate to lower the temperature of itself by making the combustion unit  11  burn to generate heat to drive the cooling unit  12  for operation, but also can be provided at the rear of itself with an electric power line  70  and an electric heating pipe  71  in connecting with the electric power line  70 . When the electric power line  70  is connected to a municipal electric power source, it can provide the electric heating pipe  71  with electric power to get the required heat, and to make the cooling unit  12  operate to maintain low temperature inside of the refrigerator  10 . In other words, in addition to that the refrigerator  10  of the present invention can burn the combustion gas to make the cooling unit  12  operate to maintain low temperature inside of the refrigerator  10  at a location such as an outdoor field lack of a municipal electric power source, the electric heating pipe  71  can also make the cooling unit  12  operate to maintain low temperature inside of the refrigerator  10  at any location such as an indoor area where a municipal electric power source is available. 
     The names of the members and the drawings for the present invention are only for illustrating preferred embodiments of the present invention, and not forgiving any limitation to the scope of the present invention. It will be apparent to those skilled in this art that various equivalent modifications or changes can be made to the elements of the present invention without departing from the spirit, scope and characteristic of this invention shall fall within the scope of the appended claims and are intended to form part of this invention.