Hydrogen-oxygen mixed gas generating system Technical Field This invention is about hydrogen-oxygen generating system which generates hydrogen oxygen mixed gas. Background Hydrogen-oxygen mixed-gas generating system is made to produce hydrogen and oxygen from electrolyzed water and to gain pollution-free energy source, hydrogen oxygen mixed gas. Water containing small amount of electrolytes is provided to the storage with positive (+) and negative (-) electrodes and electrolyzed by direct current to produce this mixture. Hydrogen and oxygen are produced at the ratio of 2 : 1 and hydrogen is formed as bubbles on the surface of negative (-) electrode and oxygen in bubbles on the surface of positive (+) electrode. Hydrogen and oxygen produced can be mixed and combusted and the mixture does not produce any pollutants when ignited, making it an important eco-friendly energy source. However, during the process of electrolyzing water, a great amount of heat is produced. To cool the heat, heat-protective system should be implicated; however, it would enlarge and complicate the machine for it will need to include various electric systems such as cooling pan or pumps. Also, hydrogen-oxygen mixed gas includes oxygen itself so it can be burned without outside oxygen. This suggests that the fire produced at the combustion always have possibility to backfire. Content of the Invention Problem to Solve The invention is created to solve above mentioned problem; by implicating the endothermic radiation system, heat can be radiated without using any electric systems 1 such as cooling pans or pumps, which would simplify the structure and provide a compact mixed gas generating system. The invention's other goal is to provide a safe hydrogen-oxygen generating system without any possibility of backfiring in combustion. The method of solution To reach the goals, a hydrogen-oxygen mixed gas generating system according to the invention include water capture-storage (10) where water is stored and hydrogen oxygen mixed gas is captured, electrode plate (20) containing multiple electrodes (21) (22) to electrolyze water, multiple water supplying pipes (30) (30') that provide water from the water capture-storage (10) to the electrode unit (20) by connecting the lower part of the water capture-storage (10) and the electrode plate (30), the gas supplying pipes (40) (40') which connect the upper water capture-storage (10) and electrode unit (20) to provide hydrogen-oxygen mixed gas produced from the electrode plate (20) to the upper part of the store water in the water capture-storage (10), the endothermic heat radiant system (50) which absorb and radiate the heat from the water capture-storage (10) in the water capture-storage (10), and the endothermic heat radiant system (50) includes multiple heat radiant pipes (51) that penetrating the water capture-storage (10) up and down and heat radiant pin formation (52) contained in the heat radiant pipes (51) to expand the contact area with air. Effect The hydrogen-oxygen generating system according to the invention, heat can be radiated through natural circulation without using any cooling pans or pumps, overall structure can be simplified and further more, it can be materialized in a compact size. Further more, by using reflux preventing filter unit, highly pure mixed gas is produced and backfire is prevented, creating a safer hydrogen-oxygen generating system. Modes for carrying out the invention The explanation below is based on the diagrams attached Diagram 1 is a sketch to explain the composition of hydrogen-oxygen mixed gas 2 generating system and the diagram 2 is a sketch to explain the endothermic heat radiant system. As drawn, the hydrogen-oxygen mixed gas generating system based on the invention contains water capture-storage (10) where water is stored and hydrogen-oxygen mixed gas is captured, electrode unit (20) to electrolyze water and multiple electrodes are built in, multiple water supplying pipes (30) (30') that provide water from the water capture storage (10) to the electrode unit (20) by connecting the lower part of the water capture storage (10) and the electrode plate (30), the gas supplying pipes (40) (40') which connect the upper water capture-storage (10) and electrode unit (20) to provide hydrogen-oxygen mixed gas produced from the electrode plate (20) to the upper part of the store water in the water capture-storage (10), the endothermic heat radiant system (50) which absorb and radiate the heat from the water capture-storage (10) in the water capture-storage (10), the water lever balancer (60) connected to the main water supplying pipe (S), supplying water from outside, maintains the certain height of water stored in the water capture- storage (10), reflux preventing filter unit (70) which is to prevent hydrogen-oxygen mixed gas inflow from the water capture- storage (10) from flowing back into the water capture-storage (10), and a nozzle (80) connected to the reflux preventing system (70) spraying hydrogen-oxygen mixed gas. Water capture-storage (10) provides water to the electrode plate (20) and capture the hydrogen-oxygen mixed gas produced from the electrode unit (20) at the same time. Water capture-storage (10) is shaped as a cylinder and is made from a metal with high durability to stand the internal pressure. Inside the water capture-storage (10) a mixed gas centrifuge (11) is installed to separate the hydrogen-oxygen mixed gas produced from the electrode unit (20) from water, and the capturing device (12) to capture the hydrogen-oxygen mixed gas can be formed at the upper part of the mixed gas centrifuge (11). In this case, catalyst, preferably tourmaline catalyst is applied on the mesh net of the mixed gas centrifuge (11). Tourmaline catalyst is coated on the mesh net or contained during the manufacturing process of the net. The mixed gas centrifuge (11) makes it possible to capture the pure hydrogen-oxygen mixed gas by filtering any debris contained in the elevating hydrogen-oxygen mixed gas produced from -, + electrodes in electrolysis or debris that came in with the water. These rubbles are more effectively 3 eliminated by the catalysis. For water capture-storage, it is favorable to form thermal conduction on the surface to increase its heat radiance efficiency. The thermal conduction can be formed by using carbon nano-tube in nanometer size, preferably in 10 to 20 nanometer, and tourmaline catalyst alone or together. The electrode unit (20)'s goal is to produce hydrogen and oxygen by electrolyzing water, thereby includes multiple negative (-) and positive (+) electrodes (21) (22) placed certain distance from away from each other. These electrodes are polished by nano technology to electrolyze water effectively and help formed hydrogen-oxygen bubbles to separate easily. Nono-technology mean polishing -, + electrodes' (21) (22) surface by nano units. Polishing by nano technology would minimize the electrodes' surface friction, making hydrogen or oxygen gas bubbles to separate easily. The technical, thermal, electrical, magnetic, and optical properties change when the size of the matter decreases from bulk to nano meter, making electrolysis on water effortless. On the surfaces of -, + electrodes (21) (22), the carbon nano-tube or tourmaline catalyst can be attached. The tourmaline catalyst would be grinded into micro to nanometer powder, burned in 1300 'C and glued to the -, + electrodes(21) (22). Tourmaline is a mineral under the hexagonal system like crystal; it produced electricity by friction, massive amount of anion, and lots of hydrogen and oxygen by electrolysis. Tourmaline becomes a catalyst with tiny pores on; it can increase the contact area with electrolyte after being powdered and burned. The tourmaline catalyst can promote the electrolysis of electrolytes when attached on -, + electrodes (21) (22). Water supplying pipes (30) (30') are pipes that provide water from water capture storage (10)to electrode unit (20) and the gas supplying pipes(40)(40') are pipes that provide hydrogen-oxygen mixed gas formed in the electrode unit (20) to water capture storage (10). The endothermic heat radiant system (50) absorbs and radiates the heat from the water capture-storage (10). Multiple heat radiant pipes (51) penetrates the water capture storage (10) from up and down and the heat radiant pins formation (52) are built inside 4 the pipes (51) to increase contact surface with air are included in the endothermic heat radiant system (50). The heat radiant pan (53) on the upper or the lower part of the heat radiant pipes (51) and the temperature sensor which would signal the heat radiant pan (53) to act when the temperature of water capture-storage (10) is above the certain temperature would be nice if implicated. The heat radiant pan (51) is composed of multiple small pipes piercing the water capture-storage from all different angles and in the example, seven pipes are used. The heat radiant pins formation (52) expands the contacting surface area of the heat radiant pipes (51). These formations (52) can be made into various shapes, however, in our example as described in the diagram 2, is a thin and long metal twisted like a screw and forms a multiple irregularities on the metal plate. The thermal conduction plate (51a) is preferably formed on the surface of the heat radiant pins formation (52) to increase the heat absorption and radiation. The thermal conduction plate (51a) is preferably composed of 10-60 nanometer size of carbon nano tube and tourmaline catalyst. The heat radiant pan (53) inhales the air and makes it go through the heat radiant pipes. The temperature sensor (54) signals the heat radiant pan (53) when the temperature of the water capture-storage (10) has elevated to high. The water level balancer(60) connected to the main water supplying pipes (S) maintains the water level stored in the water capture-storage (10) and can be formed in many different ways. In the example, the water level balancer (60) is composed of solenoid valves connected to the main water supplying pipes (S) and the water level sensor (62) inside the water capture-storage (10) that would send signals to open the solenoid valves (61) if the water level overrides the certain point. However the water level balancer (60) can be also made in the form of buoy in the toilet. The reflux preventing filter unit (70) is to make a highly pure mixed gas by eliminating any debris from the hydrogen-oxygen mixed gas flowing from the capturing system (12) through the gas line (75). It (70) also plays a role in preventing the hydrogen oxygen mixed gas flowing back to the capturing system (12). To establish the goal, the reflux preventing filter unit (70) includes water storage (71) where gas line (75) is 5 connected and water is stored, catalyst storage (72) located on the upper part of the water storage (71) storing the catalysts, and the bentyulibu (73) which connects water storage (71) and catalyst storage (72). The sub-capturing system (71a) is formed on the water storage (71) to catch the hydrogen-oxygen mixed gas traveling through the water. The catalyst storage (72) stores catalysts such as tourmaline catalyst or platinum catalyst. The catalyst storage (72) removes matters in chemical forms by catalysis. The 1" bentyulibu (73) mixes hydrogen gas and oxygen gas that goes through evenly and prevent the mixed gas transferred to the catalyst storage (72) from drawing back to the sub-capturing system (71a). To accomplish these goals, tiny water pipes are placed inside the bentyulibu (73), admiringly in a screw form. The diameter of the tiny water pipes is preferably between 0.2mm to 10mm. Actually, the hydrogen gas and oxygen gas in the water storage (71) are partially not mixed. However, as the gas travel through the bentyulibu (73), they blend into each other naturally. The water level sensing device (74) is installed inside the water storage (71). The water level sensing device (74) measures the water used and make the water tank to provide water to the water storage (71). The water level sensing device (74) can be made in various forms, such as buoy or sensor. Because water level sensor and the water tank is a technology used in the field, detailed explanation is omitted. Debris removing filter (76) can also be set up inside the water storage (71). Debris removing filter (76) removes any foreign matters included in the hydrogen-oxygen mixed gas coming through the gas line (75). According to the reflux preventing filter unit (70)'s structure described above, any rubbish included in the hydrogen-oxygen gas flowing through the gas line (75) is removed by debris removing filter (76). The filtered hydrogen-oxygen mixed gas elevates to the sub-capturing system (71a), unable to reflux to the gas line (75). And the mixed gas in the sub-capturing system (71a) become more evenly blended as it goes through the bentyulibu (73), and anything left behind is eliminated as it goes through the catalyst storage (72) becoming highly pure mixed gas. 6 Hydrogen-oxygen mixed gas generating system's mechanic will be explained according to the structure described above. According to the structure described above, when hydrogen and oxygen gas bubbles are produced when electrolysis occur between - electrode (21) and positive electrode (22) as electric current is put through the electrode unit and the mixed gas flows into the upper part of the water in the water capture-storage (10) with water through the gas providing pipes (40) (40'). Then the internal pressure in the water capture-storage increases and water flows out to the water supplying pipes (30) (30'). This means that without applying structures like pump, water is provided to the electrode unit (20) through water supplying pipes (30) (30') by the pressure of the hydrogen-oxygen mixed gas inflowing from the water capture-storage (10). Afterward, the hydrogen-oxygen mixed gas is gathered in the capturing system (12) through mixed gas centrifuge (11) and the gas in the capturing system (12) is used as combusting gas after going through the gas line (75), reflux preventing filter unit (70), and the nozzle (80). Electrolysis in the electrode unit (20) produce massive amount of heat and the heat is transferred to the water capture-storage (10) through gas supplying pipes (40) (40') elevating the temperature in the water capture-storage (10). Then the temperature of the heat radiant pipe (51) and the heat radiant pins formation (52) of the endothermic heat radiant system (50) penetrating through the water capture-storage and the temperature of the air inside the endothermic heat radiant system (50) elevates and goes outside the system. This means that natural heat radiation is conducted when the heat from the heat radiant pipe (51) and the heat radiant pins formation (52) transferred to the water capture-storage makes the air in the endothermic heat radiant system (50) making it go outside. Also when the temperature of the water capture-storage (10) elevated beyond the certain point, the heat radiant pan (53) is activated by temperature sensor (54), making immediate cooling possible. The invention is explained based on the example experimented but keep in mind that this is only one of the possibilities and anyone with sufficient knowledge in the field would understand that variations can be applied. 7 Simple explanation on the sketches Diagram 1 is a sketch to explain the composition of hydrogen-oxygen mixed gas generating system Diagram 2 is a sketch to explain the endothermic heat radiant system. Important symbols on the sketches 10 - water capture-storage 10a - thermal conduction plate 11 - mixed gas centrifuge 12 - capturing system 20 - electrode unit 21, 22 - electrodes 30, 30' - water supplying pipes 40, 40' - gas supplying pipes 50 - endothermic heat radiant system 51 - heat radiant pipe 51a - thermal conduction plate 52 - heat radiant pins formation 53 - heat radiant pan 54 - temperature sensor 60 - water level balancer 61 - solenoid valve 62 - water level sensor 70 - reflux preventing filter unit 8 71 - water storage 71a - sub-capturing system 72 - catalyst storage 73 - Bentyulibu 74 - water level sensing device 75 - gas line 76 - debris removing filter 80 - nozzle 9