JP2005221202A - Catalytic combustion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalytic combustion device capable of raising catalyst temperature to the active temperature thereof in a short time by restricting adhesion of moisture to a surface of the catalyst after starting catalytic combustion. <P>SOLUTION: A water separating filter 5 as a liquid phase capturing means provided with multiple fine passages is provided between a gas mixing unit 4 and a catalytic combustor 6 inside a passage 8 in a mixture gas flowing direction. Water drops and steam contained in the mixture gas flowing out of the gas mixing unit 4 is surely caught by the water separating filter 5, and made to stay inside the water separating filter 5, and the mixture gas, from which moisture is eliminated, can flow into the catalytic combustor 6. Problems in an existing catalytic combustion device such as instability of catalytic combustion by contact failure of the mixture gas with the catalyst due to adhesion of moisture to a surface of the catalyst and consumption of the heat generated by catalytic combustion as the water drop vaporizing latent heat can be prevented. Consequently, the catalytic combustion heater 1 capable of raising catalytic temperature to the active temperature or more in a short time is thereby realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a catalytic combustion apparatus that is used as a heat source for a heater for home use or automobile, and burns a mixed gas of air and fuel with a catalyst and heats a heat medium using the generated heat.

  Catalytic combustion devices have features such as low-temperature flameless combustion that can almost completely suppress NOx emissions, high flame safety, high absorption efficiency of far-infrared rays with high absorption rate for low-temperature heated materials, and energy saving. And is widely used.

  In general, in catalytic combustion, a combustible gas such as hydrogen gas, LPG (liquefied petroleum gas), or the like is used as a fuel, and a mixed gas of the fuel gas and air is supplied to the catalyst for catalytic combustion.

  Further, in a vehicle or the like equipped with a hydrogen fuel cell, it is preferable to use a catalytic combustion device that uses hydrogen as a fuel for heating the vehicle because the fuel mounted on the vehicle can be unified. By the way, the gas discharged from the hydrogen fuel cell (so-called off-gas) contains unreacted hydrogen that has not been used for power generation. Generally, this off gas is supplied to the hydrogen fuel cell again after being subjected to a treatment such as moisture removal. If this off gas is used as a part of the fuel of the catalytic combustion apparatus, the energy required for the off gas treatment can be saved.

  As a conventional catalytic combustion apparatus, for example, heat exchange in which an electric heating catalyst, a combustion catalyst, and a heat medium are passed through a flow path to which a mixed gas of hydrogen gas and air is supplied by a fuel supply means in order from the upstream side. To start combustion of the mixed gas of hydrogen gas and air by energizing the electric heating catalyst, and to burn the mixed gas of hydrogen gas and air even in the combustion catalyst heated by the combustion gas in the electric heating catalyst There is a configuration (see Patent Document 1).

In the conventional catalytic combustion apparatus described above, Pt (platinum) is used as a catalyst. Pt is suitable as a catalyst for a catalytic combustion apparatus because Pt has high reaction activity and can perform catalytic combustion even when the mixed gas temperature is low.
Japanese Patent Laid-Open No. 14-12211

  The catalyst has a unique temperature (activation temperature) that can sufficiently exhibit its function as a catalyst, that is, an oxidation function. That is, the activity decreases below this activation temperature.

  When the temperature of the catalytic combustion device is low, such as immediately after the start of operation of the catalytic combustion device, the catalyst temperature does not reach the activation temperature and the oxidation function is not sufficient, but the catalyst temperature rises due to the heat generated by the catalytic combustion and becomes active When the temperature is reached, stable catalytic combustion is achieved. That is, the amount of heat generated by the catalytic combustion device, that is, the amount of heat transmitted to the heat medium becomes the rated heat amount.

  By the way, when the temperature of the catalytic combustion apparatus is low, moisture contained in the air and moisture generated by catalytic combustion, that is, water vapor, may condense on the low temperature catalyst surface and adhere to the catalyst surface. In particular, when hydrogen gas is used as the fuel, most of the product resulting from catalytic combustion is water, and therefore there is a high possibility that water droplets will adhere to the catalyst surface.

  When water droplets adhere to the surface of the catalyst, the water droplets obstruct the contact between the mixed gas of fuel and air and the catalyst, thereby destabilizing catalytic combustion. That is, the amount of heat generated by catalytic combustion is reduced. Further, the water droplets adhering to the catalyst surface evaporate upon receiving the heat generated by the catalyst combustion, and ride on the mixed gas flow and flow downstream. In other words, the heat generated by catalytic combustion is lost to water droplets. That is, the amount of heat that is transferred to the heat medium in the catalytic combustion device is increased by reducing the amount of heat generated by catalytic combustion and the amount of heat generated by catalytic combustion being absorbed by water droplets, thereby increasing the time until the catalyst temperature reaches the activation temperature. There is a problem that it takes a long time to reach the rated heat quantity.

  For example, in a vehicle equipped with a hydrogen fuel cell, the catalytic combustion apparatus is used not only for heating the passenger compartment but also for warming up the fuel cell. In this case, if the temperature increase of the heat medium in the catalytic combustion device becomes slow, the warm-up time of the fuel cell becomes longer, that is, the time until the output of the fuel cell reaches a steady level at the start of the vehicle equipped with the fuel cell. The problem of lengthening arises.

  As a countermeasure against this, in the conventional catalytic combustion apparatus described above, an electric heating catalyst is provided upstream of the combustion catalyst, and the electric heating catalyst is energized to start combustion of a mixed gas of hydrogen gas and air. Thereby, the temperature of the mixed gas flowing into the combustion catalyst can be quickly increased, and moisture adhesion to the combustion catalyst can be suppressed.

  However, this method has a problem that it is necessary to add an electric heating catalyst, power consumption by the electric heating catalyst is large, and energy efficiency is lowered.

  On the other hand, a method of raising the catalyst temperature by spark-igniting and burning a mixed gas of hydrogen and air upstream of the catalyst and passing the mixed gas at a high temperature through the catalyst can be considered. In this case, since the combustion of hydrogen is continued by flame propagation, the power consumption can be suppressed.

  However, in the case of a mixed gas combustion method using sparks, it is difficult to obtain an appropriate mixing ratio because the range of the mixture ratio of hydrogen and air that can be ignited is narrow. There are problems such as the need for countermeasures.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to reduce the adhesion of moisture to the catalyst surface after the start of catalytic combustion and to reduce the catalyst temperature in a short time by adopting easy means. It is an object of the present invention to provide a catalytic combustion apparatus that can be raised above the activation temperature.

  The present invention employs the following technical means to achieve the above object.

  The catalytic combustion apparatus according to claim 1 of the present invention includes a gas mixing means for forming a mixed gas of air and fuel, an air supply means for supplying air to the gas mixing means, and a fuel for supplying fuel to the gas mixing means. A supply means, a passage connected to the gas mixing means and supplied with the mixed gas formed by the gas mixing means, and disposed downstream of the gas mixing means in the passage and formed by supporting the catalyst on the catalyst carrier A catalytic combustion apparatus comprising a catalytic combustion section provided with a liquid phase collection means comprising a number of fine passages in the passage between the gas mixing means and the catalyst combustion part in the flow direction of the mixed gas It was.

  When the catalyst temperature immediately after the start of operation of the catalytic combustion apparatus is low, moisture contained in the air, that is, water vapor, may condense on the low temperature catalyst surface and adhere to the catalyst surface. In particular, when off-gas discharged from a hydrogen fuel cell is used as fuel, the off-gas contains a large amount of water vapor, which is a reaction product of the fuel cell. Very expensive.

  When moisture adheres to the catalyst surface, the contact between the catalyst and the mixed gas is hindered and the catalytic function is lowered, that is, the calorific value of catalytic combustion is reduced. In addition, the heat generated by the combustion of the catalyst is lost as the latent heat of vaporization of the water droplets adhering to the catalyst, so that the temperature rise of the catalyst itself becomes slow, and there is a problem that it takes a long time for the catalyst temperature to reach the activation temperature.

  According to the configuration of the catalytic combustion apparatus of the first aspect of the present invention, the mixed gas flowing out from the gas mixing means flows into the catalytic combustion section after passing through the liquid phase collecting means. Here, since the liquid phase collecting means includes a large number of fine passages, water droplets and water vapor, which are moisture contained in the mixed gas, collide with and adhere to the wall surface of the fine passage. Therefore, water droplets and water vapor, which are moisture, can be removed from the mixed gas by the liquid phase collecting means.

  This allows the mixed gas from which water droplets and water vapor have been removed to flow into the catalytic combustion section, so that after catalyst combustion starts, moisture adhesion to the catalyst surface is suppressed and the catalyst temperature rises above the activation temperature in a short time. The catalytic combustion apparatus which can be made to be able to be made can be provided.

  When water particles are large, that is, water droplets are reliably captured by the liquid phase collection means, but water particles with small water vapor may pass through without being captured by the liquid phase collection means. However, since such small particles hardly adhere to the catalyst surface, there is no possibility of condensation on the catalyst surface and deteriorating the function of the catalyst.

  By the way, after the start of catalytic combustion, the amount of water staying in the liquid phase collecting means increases with time. At the same time, the temperature of the catalytic combustion section rises due to catalytic combustion, and accordingly, the temperature of the liquid phase collecting means rises by receiving radiant heat from the catalytic combustion section. For this reason, the water | moisture content staying in a liquid phase collection means evaporates, and flows into a catalyst combustion part with mixed gas. However, since the temperature of the catalyst combustion part is sufficiently high, that is, above the activation temperature of the catalyst, the water vapor that flows along with the mixed gas flows out of the catalyst combustion part without adhering to the catalyst surface.

  In the catalytic combustion apparatus according to claim 2 of the present invention, the liquid phase collecting means includes a heat generating means.

  In this case, for example, the heat generation means included in the liquid phase collection means is heated simultaneously with the start of the operation of the catalytic combustion apparatus, and the temperature of the liquid phase collection means is increased, so that the water vapor passing through the liquid phase collection means is increased. The temperature can be increased to make the water particles of water vapor smaller. Thereby, it can prevent reliably that the water vapor | steam which flows into a catalyst combustion part with mixed gas adheres to the catalyst surface.

  Further, the heat generated by the heat generating means can accelerate the temperature rise of the liquid phase collecting means and promote the re-evaporation of the water staying in the liquid phase collecting means. For this reason, the amount of water staying in the liquid phase collecting means can be reduced, and the liquid phase collecting means can be downsized.

  In the catalytic combustion apparatus according to claim 3 of the present invention, the heating means is an electric heating element.

  In this case, since the heat generation amount of the heat generating means can be easily controlled, the heat generation amount of the heat generating means can be adjusted as necessary, and the energy consumption by the heat generating means can be minimized.

  The catalytic combustion apparatus according to claim 4 is configured such that the liquid phase collecting means is formed of a conductive material and generates heat when energized.

  In this case, since the liquid phase collection means itself generates heat, the heat generation means becomes unnecessary. Therefore, without increasing the number of parts and physique, the temperature of the water vapor passing through the liquid phase collecting means is increased to make the water particles of the water vapor smaller, so that the water vapor flowing into the catalytic combustion section together with the mixed gas is applied to the catalyst surface Adherence can be reliably prevented.

  Further, since the liquid phase collecting means itself generates heat, the temperature of the liquid phase collecting means can be quickly raised, and power consumption by the liquid phase collecting means can be saved.

  In the catalytic combustion apparatus according to claim 5 of the present invention, the liquid phase collecting means is a porous air-permeable solid.

  The porous air-permeable solid is generally formed from various monolith ceramics, sintered metal, and the like, and fine air holes communicate with each other in a complex manner. For this reason, the water droplet and water vapor | steam which are the water | moisture contents in mixed gas can be capture | acquired reliably.

  Moreover, in the case of various monolith ceramics, sintered metal, etc., it can be easily molded into a shape that can be installed in the passage of the catalytic combustion apparatus.

  The catalytic combustion apparatus according to claim 6 of the present invention is configured such that the fuel is hydrogen gas.

  Thereby, for example, even when applied to a fuel cell stack preheating device or the like of a hydrogen fuel cell system using hydrogen as a fuel, the catalyst temperature can be raised to the activation temperature in a short time after the start of catalytic combustion.

  According to a seventh aspect of the present invention, there is provided the catalytic combustion apparatus, which is disposed downstream of the catalytic combustion section in the passage and is supplied with a heat medium to generate heat between the heat medium and the combustion gas from the catalytic combustion section. It was set as the structure provided with the heat exchanger which replaces | exchanges.

  In this case, the heat generated in the catalytic combustion unit is transmitted to the heat medium by the heat exchanger, the heat medium is guided to a predetermined place, and the heat of the heat medium can be used there. That is, even when the catalytic combustion apparatus is separated from the portion that uses the generated heat, the generated heat of the catalytic combustion section can be easily used through the heat medium.

(First embodiment)
Hereinafter, the case where the catalytic combustion apparatus according to an embodiment of the present invention is applied to a catalytic combustion heater 1 mounted on a fuel cell vehicle using hydrogen as a fuel and used for vehicle interior heating of the vehicle will be described with reference to the drawings. To do.

  FIG. 1 is a schematic diagram illustrating the overall configuration of a heating system 100 including a catalytic combustion heater 1 according to a first embodiment of the present invention.

  FIG. 2 is a partial cross-sectional view of the catalytic combustion heater 1 according to the first embodiment of the present invention.

  As shown in FIG. 1, the heating system 100 is a catalyst combustion heater 1, a heater core that is an apparatus for exchanging heat of water, which is a heat medium heated by the catalyst combustion heater 1, with air and using it for vehicle interior heating. Reference numeral 101 denotes a pump 102 for pressurizing water as a heat medium and circulating it between the catalytic combustion heater 1 and the heater core 101.

  The catalytic combustion heater 1 uses a fuel common to a fuel cell as a power source of the vehicle, that is, hydrogen, and raises the temperature of water as a heat medium by catalytic combustion of the fuel.

  Below, the structure of the catalytic combustion heater 1 by 1st Embodiment of this invention is demonstrated.

  As shown in FIG. 2, the catalytic combustion heater 1 is formed with a passage 81 in which a mixed gas of hydrogen gas and air as a fuel is supplied in a casing 8 as a container. Further, a hydrogen introduction part 32 for introducing hydrogen gas from the blower 2 as air supply means and the hydrogen supply device 3 as fuel supply means into the passage 81, and a gas for mixing air and hydrogen gas to form a mixed gas of both A gas mixer 4 which is a mixing means, a water separation filter 5 which is a liquid phase collecting means, a catalyst combustor 6 which is a catalytic combustion section, and a heat exchanger 7 are arranged.

  The casing 2, which is a container, is formed of a heat-resistant metal, such as a stainless steel plate, and its internal space forms a passage 81 through which a mixed gas of hydrogen gas and air as fuel flows, as shown in FIG. .

  At the upstream end (the left end in FIG. 2) of the passage 81, the blower 2 as air supply means is disposed. The blower 2 is driven by an electric motor, and supplies air sucked through a filter (not shown) into the passage 81. On the downstream side of the blower 2 (on the right side in FIG. 2), a hydrogen introduction portion 32 that supplies hydrogen gas as fuel to the gas mixer 4 described later is disposed.

  The fuel supply means for supplying fuel to the gas mixer 4 adjusts the pressure of hydrogen gas supplied from the outside to a predetermined value and controls the flow rate of hydrogen gas supplied to the gas mixer 4 to a desired value. 3, a hydrogen introduction part 32 that is arranged upstream of the gas mixer 4 and uniformly introduces hydrogen gas into the gas mixer 4, and a hydrogen passage that supplies hydrogen from the hydrogen gas supply device 3 to the hydrogen introduction part 32 31.

  In the case of the catalytic combustion heater 1 according to the first embodiment of the present invention, the hydrogen gas supplied to the hydrogen gas supply device 3 is supplied from a hydrogen tank (not shown) that is a component of the fuel cell system mounted on the vehicle. , And an off-gas passage that is exhaust gas from a fuel cell (not shown). For example, hydrogen gas is supplied from a hydrogen tank (not shown) only when off gas is preferentially supplied to the hydrogen gas supply device 3 and only the off gas is insufficient with respect to the hydrogen gas flow rate required by the catalytic combustion heater 1. Gas is supplied.

  The hydrogen introduction unit 32 uniformly introduces hydrogen gas supplied from the hydrogen supply device 3 serving as fuel supply means through the hydrogen passage 31 into the passage 81 in the outer peripheral direction of the passage 81. A gas mixer 4 that is a gas mixing means is disposed on the downstream side (right side in FIG. 2) of the hydrogen introduction part 32.

  The gas mixer 4 is constituted by, for example, a so-called static mixer having a configuration in which a spiral fixed blade (not shown) is disposed in a pipe-shaped passage (not shown), and the inside of the gas mixer 4 is air and hydrogen gas. Is passed (from left to right in FIG. 2), a mixed gas of air and hydrogen gas is formed by the above-described spiral fixed blade. The hydrogen concentration in the mixed gas is substantially uniform in the cross section of the passage 81 in the direction orthogonal to the mixed gas flow. A water separation filter 5 which is a liquid phase collecting means is installed on the downstream side of the gas mixer 4 (the right side in FIG. 2).

  The water separation filter 5 is formed in a plate shape from monolith ceramics, for example, cordierite, as a porous air-permeable fixing. In general, when the water separation filter 5 is made of monolith ceramics, a mixture of ceramic particles and a binder is formed into the shape of the water separation filter 5 and then fired at a high temperature. At this time, the binder is volatilized in the firing step, and the ceramic particles are in a sintered state. That is, a large number of holes are formed in the portion where the binder exists. These holes have a complicated shape inside the water separation filter 5 and communicate with each other to form a large number of fine passages. These fine passages are not formed linearly from the upstream side to the downstream side of the water separation filter 5, but are formed to meander and bend. Therefore, when the mixed gas of air and hydrogen gas flowing out from the gas mixer 4 passes through the water separation filter 5 from the left side to the right side in FIG. 2, the mixed gas becomes the wall surface of the fine passage of the water separation filter 5. Will flow with repeated collisions. As a result, fine water droplets and water vapor, which are water contained in the mixed gas, collide with and adhere to the wall surface of the fine passage of the water separation filter 5. As a result, the water separation filter 5 can reliably capture and collect fine water droplets and water vapor in the mixed gas.

  By causing the mixed gas from which moisture has been removed to flow into the catalytic combustor 6, a problem in the conventional catalytic combustion apparatus, that is, immediately after the start of the operation of the catalytic combustion apparatus, the low temperature of the water contained in the mixed gas is low. By adhering to the catalyst surface, the contact between the mixed gas and the catalyst is hindered and the catalyst combustion becomes unstable, and it is possible to reliably prevent the heat generated by the catalyst combustion from being consumed as the latent heat of vaporization of water droplets. . Thereby, catalyst temperature can be raised to activation temperature in a short time.

  By the way, in the water separation filter 5, the moisture collection characteristic becomes higher as the number of collisions with the fine passage wall surface when the mixed gas passes through the water separation filter 5 increases. The number of collisions of the mixed gas with the water separation filter 5 decreases the particle diameter of the cordierite and decreases the porosity of the water separation filter 5 (the ratio of the volume of all the pores to the apparent volume of the water separation filter 5). This can be increased. However, if it does in this way, ventilation resistance of water separation filter 5 will increase, and in order to secure a predetermined mixed gas flow rate, it will be necessary to raise more generation pressure of blower 3, and generation pressure of a hydrogen supply device. This leads to an increase in the size of the catalytic combustion heater 1. Therefore, in order to realize the water separation filter 5 that can obtain a low pressure loss while maintaining high moisture collection efficiency, it is necessary to appropriately select the particle diameter of cordierite and the porosity of the water separation filter 5.

  The catalytic combustor 6 generates high-temperature combustion gas by catalytic combustion of a mixed gas of air and hydrogen gas. That is, the heat generating part in the catalytic combustion heater 1 according to the first embodiment of the present invention is formed. The catalytic combustor 6 is one in which Pt (platinum) is supported as a catalyst on a catalyst carrier 61 formed in a honeycomb shape from monolith ceramics, for example, alumina, cordierite or the like.

  On the downstream side of the catalytic combustor 6 (right side in FIG. 2), heat exchange is performed to exchange heat between the mixed gas that has become high temperature by catalytic combustion, that is, between the combustion gas from catalytic combustion and the coolant that is the heat medium. A vessel 7 is arranged. As the coolant, for example, water or an aqueous ethylene glycol solution is used. The heat exchanger 7 includes a plurality of tubes 71 arranged so as to be orthogonal to the mixed gas flow in the passage 81 and fins 72 arranged in contact with both tubes 71 so as to allow heat conduction between the adjacent tubes 71. Yes. Since the tube 71 and the fin 72 are exposed to a high-temperature mixed gas and the coolant flows in the tube 71, it is desirable that the tube 71 and the fin 72 be formed of a material having excellent heat resistance and corrosion resistance. According to the first embodiment of the present invention, The catalytic combustion heater 1 is formed from a stainless steel plate. Further, as shown in FIG. 1, the heat exchanger 7 is heated by a pump 102 through a heater delivery pipe 73 and a heater core 101 that supply high-temperature coolant from the heat exchanger 7 to the heater core 101 of the heating system 100. A heater return pipe 74 for introducing pressurized coolant is provided. The coolant that has flowed into the one end side of each tube 71 from the heater return pipe 74 is heat-exchanged with the combustion gas flowing outside the tube 71 while passing through the tube 71, and the temperature is increased. It flows out to the heater core 101 through the heater delivery pipe 73.

  Next, the operation and effect of the water separation filter 5 which is the feature of the catalytic combustion heater 1 according to the first embodiment of the present invention described above will be described in correspondence with the operating state of the catalytic combustion heater 1.

  (1) Immediately after the start of the operation of the catalytic combustion heater 1.

  When the catalytic combustion heater 1 starts to operate, air is supplied from the blower 2 and hydrogen gas (off-gas) is supplied from the hydrogen supply device 3 to the gas mixer 4. Then, the mixed gas formed by the gas mixer 4 flows into the water separation filter 5.

  When the mixed gas passes through the water separation filter 5, water drops and water vapor in the air supplied from the blower 2 and water drops and water vapor in the off-gas that is hydrogen gas supplied from the hydrogen supply device 3 are removed from the water separation filter 5. It collides with and adheres to the wall surface of the fine passage.

  Here, immediately after the start of the operation of the catalytic combustion heater 1, the temperature of the water separation filter 5 is at a low level, that is, the outside air temperature level. Therefore, water droplets and water vapor captured by the water separation filter 5 stay in the water separation filter 5 as they are.

  Further, when water droplets or water vapor in the mixed gas flowing into the water separation filter 5 collides with water droplets already captured on the wall surface of the fine passage of the water separation filter 5, they adhere to it.

  As a result, water droplets and water vapor in the mixed gas are removed by the water separation filter 5, so that the mixed gas containing no water droplets and water vapor flows into the catalytic combustor 6.

  When the mixed gas flows into the catalytic combustor 6, the mixed gas immediately undergoes catalytic combustion, and the temperature of the catalyst carried on the catalytic combustor 6 rises due to the generated heat. Here, since the mixed gas does not contain moisture, contact of the mixed gas with the catalyst is hindered due to moisture adhering to the catalyst surface as in the conventional catalytic combustion apparatus, the catalytic combustion becomes unstable, and the heat generated by the catalytic combustion is reduced. It is not consumed as the latent heat of vaporization of water droplets. Therefore, in the catalytic combustion heater 1 according to the first embodiment of the present invention, the catalyst temperature can be raised to the activation temperature in a short time.

  Moreover, in the catalytic combustion heater 1 according to the first embodiment of the present invention, cordierite is adopted as the material of the water separation filter 5, but the cordierite has a polarity on the surface. On the other hand, water molecules have polarity due to their atomic arrangement. For this reason, the fine passage wall surface of the water separation filter 5 having polarity and the water droplets and water vapor having polarity attract each other, and the water droplets and water vapor adhere to the catalyst also by the attractive force. That is, in the catalytic combustion heater 1 according to the first embodiment of the present invention, the water separation filter 5 is formed of cordierite, and the intermolecular attractive force is also used for the water droplet and water vapor collecting action of the water separation filter 5. Yes. Therefore, water droplets and water vapor in the mixed gas can be collected with higher efficiency.

  In addition, the porous breathable solid having polarity similar to cordierite includes γ-alumina and the like, and even when the water separation filter 5 is formed of γ-alumina, intermolecular attractive force is collected in collecting water droplets and water vapor. Can be used.

  (2) When a certain period of time has elapsed after the start of the operation of the catalytic combustion heater 1.

  When time elapses after the start of the operation of the catalytic combustion heater 1, the temperature of the water separation filter 5 rises due to the radiant heat from the catalytic combustor 6.

  As a result, the water remaining in the water separation filter 5 evaporates to become water vapor, and rides on the flow of the mixed gas, leaves the water separation filter 5 and flows into the catalytic combustor 6.

Further, water droplets and water vapor newly included in the mixed gas from the gas mixer 4 and flowing into the water separation filter 5 evaporate after adhering to the water separation filter 5 once or passing through the water separation filter 5. Then, it also rides on the flow of the mixed gas, leaves the water separation filter 5 and flows into the catalytic combustor 6.
At this time, since the temperature of the catalytic combustor 6 is sufficiently high, the water vapor that flows together with the mixed gas flows out of the catalytic combustor 6 without adhering to the catalyst surface.

  In the catalytic combustion heater 1 according to the first embodiment of the present invention described above, a liquid phase having a number of fine passages in the middle of the gas mixer 4 and the catalytic combustor 6 in the flow direction of the mixed gas in the passage 8. A water separation filter 5 as a collecting means was provided.

  The mixed gas produced by the gas mixer 4 contains moisture contained in air or the like. In the catalytic combustion heater 1 according to the first embodiment of the present invention, off gas discharged from the fuel cell is used as hydrogen gas, but the off gas contains a large amount of water vapor, which is a reaction product in the fuel cell. Yes.

  In the catalytic combustion heater 1 according to the first embodiment of the present invention, water droplets and water vapor in the mixed gas flowing out from the gas mixer 4 are reliably captured by the water separation filter 5 and retained in the water separation filter 5. Yes.

  As a result, the mixed gas from which moisture has been removed can flow into the catalytic combustor 6, so that contact between the mixed gas and the catalyst is hindered due to moisture adhering to the catalyst surface as in the conventional catalytic combustion apparatus, and catalytic combustion. Becomes unstable and the heat generated by catalytic combustion is not consumed as the latent heat of vaporization of water droplets. Therefore, the catalytic combustion heater 1 that can raise the catalyst temperature to the activation temperature or higher in a short time can be realized.

  In the catalytic combustion heater 1 according to the first embodiment of the present invention described above, the water separation filter 5 is formed of cordierite. However, the water separation filter 5 is not limited to cordierite and can capture water droplets and water vapor. Other materials may be used as long as they are porous and breathable solids. For example, you may form from gamma alumina. Furthermore, you may form from materials other than ceramic material, for example, a sintered metal.

(Second Embodiment)
In FIG. 3, the fragmentary sectional view of the catalytic combustion heater 1 by 2nd Embodiment of this invention is shown.

  In the catalytic combustion heater 1 according to the second embodiment of the present invention, the configuration of the water separation filter 5 is changed with respect to the catalytic combustion heater 1 according to the first embodiment of the present invention.

  That is, the water separation filter 5 is equipped with an electric heater 51 which is a heat generating means and is an electric heating element. For example, a nichrome wire, a nickel wire, or the like is used for the electric heater 51 and is embedded in the cordierite when the water separation filter 5 is molded. Further, as shown in FIG. 3, the electric heater 51 is electrically connected to the outside of the catalytic combustion heater 1 by lead wires 52 and 53.

  In this case, energization of the electric heater 51 is started simultaneously with the start of the operation of the catalytic combustion heater 1 to cause the electric heater 51 to generate heat, thereby faster than the catalytic combustion heater 1 according to the first embodiment of the present invention. The temperature of the water separation filter 5 can be increased.

  Thereby, after the start of the operation of the catalytic combustion heater 1, it is possible to shorten the time during which water droplets and water vapor trapped in the water separation filter 5 stay.

  The water separation filter 5 has a function of capturing water droplets and water vapor in the mixed gas and storing the captured water. That is, the water separation filter 5 receives a radiant heat from the catalyst combustor 6 and becomes high temperature, and water droplets and water vapor newly flowing into the water separation filter 5 are temporarily evaporated after adhering to the water separation filter 5, or the water separation filter. The time required to evaporate while passing through the interior 5 needs to have a capacity sufficient to store the trapped moisture so as not to flow out, that is, the length in the mixed gas flow direction.

  In the catalytic combustion heater 1 according to the second embodiment of the present invention, an electric heater 51 is attached to the water separation filter 5 so that water droplets or water vapor newly flowing into the water separation filter 5 is passing through the water separation filter 5. The time to evaporate is shortened. In other words, the amount of water stored in the water separation filter 5 is reduced. Thereby, since the length of the water separation filter 5 in the mixed gas flow direction can be shortened, the catalytic combustion heater 1 can be reduced in size.

  In the catalytic combustion heater 1 according to the second embodiment of the present invention, the electric heater 51 is embedded in the water separation filter 5, that is, the electric heater 51 and the water separation filter 5 are integrated. However, the electric heater 51 and the water separation filter 5 may be formed as two independent parts, and the electric heater 51 may be disposed in the passage 81 on the upstream side of the water separation filter 5.

(Third embodiment)
In FIG. 4, the fragmentary sectional view of the catalytic combustion heater 1 by 3rd Embodiment of this invention is shown.

  In the catalytic combustion heater 1 according to the third embodiment of the present invention, the configuration of the water separation filter 5 is changed with respect to the catalytic combustion heater 1 according to the first embodiment of the present invention.

  That is, the water separation filter 5 is formed from a conductive substance and a porous air-permeable solid. Further, as shown in FIG. 4, the water separation filter 5 is electrically connected to the outside of the catalytic combustion heater 1 via lead wires 54 and 55. When the water separation filter 5 is energized, Joule heat is generated by its own electrical resistance, and the temperature rises.

  Examples of such a conductive substance and a porous air-permeable solid include a sintered metal or a conductive ceramic.

  In this case as well, the energization of the water separation filter 1 is started simultaneously with the start of the operation of the catalytic combustion heater 1 to cause the water separation filter 5 to generate heat, similarly to the case of the catalytic combustion heater 1 according to the second embodiment of the present invention. Compared to the catalytic combustion heater 1 according to the first embodiment of the present invention, the temperature of the water separation filter 5 can be increased more quickly.

  Therefore, also in the catalytic combustion heater 1 according to the third embodiment of the present invention, the same effect as that of the catalytic combustion heater 1 according to the second embodiment of the present invention can be obtained. That is, the time until water droplets or water vapor newly flowing into the water separation filter 5 evaporates while passing through the water separation filter 5 is shortened, and the length of the water separation filter 5 in the mixed gas flow direction is shortened. Therefore, the catalytic combustion heater 1 can be reduced in size.

  The above-described catalytic combustion heaters 1 according to the first to third embodiments of the present invention each include the heat exchanger 7 and have a function of being incorporated in the heating system 100 and increasing the temperature of the coolant that is a heat medium. Plays. However, it is not necessary to limit the application of the catalytic combustion heater 1 according to the present invention to heating the heating medium of the heating system 100. For example, the heat exchanger 7 may be eliminated, and the catalytic combustion heater 1 according to the present invention may be used for use in which the combustion gas flowing out from the catalytic combustor 6 is used as hot air.

  In this case, since hydrogen gas is used as the fuel for catalytic combustion, the components of the combustion gas flowing out from the catalytic combustor 6 are air and water vapor, and no harmful substances such as NOx are included. Therefore, the combustion gas flowing out from the catalytic combustion heater 1 can be directly used for indoor heating.

  In the catalytic combustion heater 1 according to the first to third embodiments of the present invention described above, hydrogen gas is used as the fuel. However, it is not necessary to limit to hydrogen gas, and other types of gaseous fuels are used. May be used.

It is a mimetic diagram explaining the whole heating system 100 composition containing catalyst combustion heater 1 by a 1st embodiment of the present invention. 1 is a partial cross-sectional view of a catalytic combustion heater 1 according to a first embodiment of the present invention. It is a fragmentary sectional view of the catalytic combustion heater 1 by 2nd Embodiment of this invention. It is a fragmentary sectional view of the catalytic combustion heater 1 by 3rd Embodiment of this invention.

Explanation of symbols

1 Catalytic combustion heater (catalytic combustion equipment)
2 Blower (Air supply means)
3 Hydrogen supply device (fuel supply means)
31 Hydrogen passage (fuel supply means)
32 Hydrogen introduction part (fuel supply means)
4 Gas mixer (gas mixing means)
5 Water separation filter (liquid phase collecting means)
51 Electric heater (heating means, electric heating element)
52 Lead wire 53 Lead wire 54 Lead wire 55 Lead wire 6 Catalytic combustor 61 Catalyst carrier 7 Heat exchanger 71 Tube 72 Fin 73 Heater feed pipe 74 Heater return pipe 8 Casing 81 Passage 9
100 Heating System 101 Heater Core 102 Pump

Claims (7)

A gas mixing means for forming a mixed gas of air and fuel;
Air supply means for supplying air to the gas mixing means;
Fuel supply means for supplying the fuel to the gas mixing means;
A passage connected to the gas mixing means and supplied with the mixed gas formed by the gas mixing means;
A catalytic combustion device that is disposed downstream of the gas mixing means in the passage and includes a catalytic combustion section formed by supporting a catalyst on a catalyst carrier;
A catalytic combustion apparatus comprising a liquid phase collecting means having a number of fine passages in the passage between the gas mixing means and the catalytic combustion section in the flow direction of the mixed gas.   The catalytic combustion apparatus according to claim 1, wherein the collection unit includes a heat generation unit.   The catalytic combustion apparatus according to claim 2, wherein the heat generating means is an electric heating element.   The catalytic combustion apparatus according to claim 1, wherein the collecting means is made of a conductive material and generates heat when energized.   The catalytic combustion apparatus according to any one of claims 1 to 4, wherein the collecting means is a porous air-permeable solid.   The catalytic combustion apparatus according to any one of claims 1 to 5, wherein the fuel is hydrogen gas.   A heat exchanger is provided in the passage on the downstream side of the catalyst combustion unit, and a heat exchanger is provided to exchange heat between the heat medium and the combustion gas from the catalyst combustion unit. The catalytic combustion apparatus according to any one of claims 1 to 6.

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