JP3766814B2 - Catalytic combustion apparatus and control method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a catalytic combustion apparatus that mixes vaporized fuel with air and performs catalytic combustion in a catalyst layer, and a control method thereof.
[0002]
[Prior art]
Catalytic combustion is known in which the combustion temperature is lower than flame combustion, and combustion is performed without flame. Catalytic combustion is a clean combustion method with few harmful components in combustion exhaust gas such as NOx. In addition, the combustion sound is low, so it is quiet, and since it does not generate flames, it is a highly safe combustion method. Further, since there are various merits such as being able to make use of a large amount of infrared rays emitted from the catalytic combustion layer, development is being promoted as a device for heating or drying.
[0003]
A catalytic combustion apparatus in which a plate-like catalyst layer is disposed in the front, and a supply chamber is provided at the rear of the catalyst layer for mixing vaporized fuel and air and supplying the mixture to the front catalyst plate. Infrared rays emitted from the plate can be efficiently used for heating and the like. In this type of catalytic combustion device, the supply chamber is heated by infrared rays radiated from the catalyst plate into the supply chamber, so that the fuel and air can be preheated by the heat from the catalytic combustion, and a stable catalyst with a simple configuration. Combustion can be realized. Further, as the fuel, a gas obtained by vaporizing a liquid fuel such as gas oil as well as a gas such as gas can be used. However, the liquid fuel can be vaporized by heat of catalytic combustion in the supply chamber. In such a catalytic combustion apparatus, the supply chamber may be called a vaporization chamber.
[0004]
[Problems to be solved by the invention]
In the catalytic combustion apparatus, when the temperature of the supply chamber rises excessively during catalytic combustion, a so-called flashback phenomenon (back combustion) occurs in which fuel burns in the supply chamber. When flame combustion occurs, the catalytic combustion effect characterized by flameless combustion cannot be obtained. On the other hand, if the temperature of the supply chamber is too low, the temperature of the catalyst plate is lowered, the combustion efficiency is lowered, and in the worst case, the combustion is not continued. Further, in the case of a combustion apparatus of a type that vaporizes liquid fuel, the vaporization efficiency is lowered when the temperature of the supply chamber is lowered, or the phenomenon of reliquefaction occurs and the combustion efficiency is lowered. Therefore, it is desirable to maintain the temperature of the supply chamber at such a high temperature that back combustion does not occur.
[0005]
However, the temperature of the supply chamber varies depending on various factors. For example, if the temperature (outside air temperature) of the outside air supplied to the supply chamber rises, the temperature of the supply chamber rises, so that back combustion is likely to occur. At the timing when the output of the catalytic combustion apparatus is increased, the amount of fuel and air supplied increases, so the temperature of the supply chamber decreases. Conversely, at the timing when the output decreases, the temperature of the supply chamber tends to increase. Furthermore, if the capacity of the supply chamber is large, the temperature change due to various factors becomes relatively small. However, if the capacity of the supply chamber is made as small as possible to provide a compact catalytic combustion apparatus, the temperature change tends to be large. Further, the possibility of back combustion is increased.
[0006]
Since the back combustion itself can be easily extinguished by shutting off the fuel supply for a short period of time when it occurs, it does not become dangerous due to the occurrence of a flame. However, it is easy for the user to judge that the state of intermittently shutting off the fuel is an unstable state, which is not a preferable combustion state. In addition, by repeating the generation and stop of the flame, vibrations and rapid temperature changes are applied to the catalyst plate, which may cause deterioration in durability. On the other hand, when a design that does not generate back combustion is adopted, the temperature of the supply chamber is lowered and the combustion efficiency is lowered or incomplete combustion is caused. Also, a design that enlarges the supply room is not an economical design.
[0007]
Therefore, the present invention provides a catalytic combustion apparatus that can maintain the temperature of the supply chamber at a high temperature at which back combustion does not occur even if various environments of the catalytic combustion apparatus change, and a control method therefor. And it aims at providing the catalytic combustion apparatus which can enjoy the merit of catalytic combustion, such as compact, good combustion efficiency, and low noise and clean exhaust gas.
[0008]
[Means for Solving the Problems]
For this reason, in the catalytic combustion apparatus of the present invention, when it is determined that a flame is detected during catalytic combustion, a control is adopted in which the amount of outside air supplied to the supply chamber is increased. By increasing the amount of outside air supplied to the supply chamber, the temperature of the supply chamber is lowered, so that back combustion can be prevented. Further, since the amount of fuel is not decreased by increasing the amount of outside air to prevent back combustion, the output of the catalytic combustion apparatus can be maintained at the target output desired by the user. Furthermore, since the control is performed by directly checking the presence or absence of a flame, not the indirect control for keeping the temperature of the supply chamber constant, as described above, the supply chamber is maintained at a high temperature so that back combustion does not occur. The catalytic combustion apparatus can be maintained in a stable state with the best combustion efficiency.
[0009]
That is, the catalytic combustion apparatus of the present invention has a catalyst plate for catalytic combustion of vaporized fuel, a supply chamber for supplying the catalyst plate with fuel and outside air mixed, and an amount of outside air supplied to the supply chamber. Control means for controlling based on the value, means for detecting the flame generated in the supply chamber, Means for measuring the temperature of the supply chamber and means for measuring the outside air temperature; When the control means determines that a flame has been detected during catalytic combustion, the control means increases the target value. If it is determined that the temperature of the supply chamber has decreased, the target value is lowered. Further, if it is determined that the outside air temperature has fluctuated beyond the predetermined range, the previous target value is canceled once, The target value is set to a value associated with the outside air temperature in advance so that stable catalytic combustion can be obtained. The Therefore, the present invention Catalytic combustion equipment control Do The method includes a step of controlling the amount of outside air supplied to the supply chamber based on a target value, and a step of increasing the target value when it is determined that a flame is detected during catalytic combustion. If it is determined that the temperature of the supply chamber has decreased, the target value is lowered, and if it is determined that the outside air temperature has fluctuated beyond a predetermined range, the previous target value is canceled once, Setting a target value to a value associated with the outside air temperature in advance so that stable catalytic combustion can be obtained. Have This control method can also be realized by a sequencer. Moreover, in a catalytic combustion apparatus equipped with a program control device such as a microcomputer, When the program controller determines that the flame is detected by the means for detecting the flame generated in the supply chamber during catalytic combustion, the target value of the rotation speed of the blower that supplies outside air to the supply chamber is increased. When it is determined that the temperature of the supply chamber has been lowered by the means for measuring the temperature, the temperature is lowered. Further, when the means for measuring the outside air temperature is determined to have fluctuated beyond the predetermined range, the previous target value is temporarily set. To cancel and set the value associated with the outside temperature in advance so that basically stable catalytic combustion is obtained at that outside temperature. The program or control program product can be realized by being recorded on an appropriate recording medium or provided via a computer network.
[0010]
When the temperature of the supply chamber is controlled to the extent that back combustion does not occur due to the detection of flame, when the combustion conditions change and back combustion occurs again, it can be dealt with by increasing the air volume again. . However, if back combustion does not occur, there is a possibility that the temperature of the supply chamber will be too low. Therefore, it is desirable to provide means for measuring the temperature of the supply chamber, and to lower the target value when the control means determines that the temperature of the supply chamber, for example, the temperature of the outer shell of the supply chamber has decreased. That is, in the control method, it is desirable to provide a step of lowering the target value when it is determined that the temperature of the supply chamber has decreased. By this step, the air volume can be lowered and the temperature of the supply chamber can be raised. If back combustion occurs due to a reduction in the air volume, the air volume increases accordingly, so that the temperature of the supply chamber can be raised to the extent that back combustion does not occur.
[0011]
Catalytic combustion device In order to raise the temperature of the supply chamber to such an extent that back combustion does not occur when the environment changes, the air volume is finally adjusted by detecting the flame after catalytic combustion is performed in a state suitable for the environment. It is desirable to do so. Therefore, for the outside air temperature, a means for measuring the outside air temperature is provided, and the control means Beyond the prescribed range If you think it has fluctuated, Cancel the target value before that, Pre-associated with its outside temperature value Target value Setting And then the flame is detected Then It is desirable to add to the target value. Value associated with the outside air temperature in advance (outside air temperature factor value) May be obtained by a function having the outside air temperature as a variable, or may be obtained from a lookup table set in advance for the outside air temperature. Of course, it is possible to use a function or look-up table that takes into account other effects such as atmospheric pressure.
[0012]
In addition, when it is determined that the temperature of the supply chamber is lower than the set value, the target value is once reset to a value obtained by subtracting the room temperature factor value previously associated with the room temperature factor value, and then a flame is detected. It is desirable to add the flame factor value related to the number of times to the target value. In order not to repeat the control that requires the air volume to decrease due to the increase in the air volume due to the detection of the flame, the fluctuation range due to the flame factor value should be changed according to the room temperature factor value. It is desirable to make it smaller than the width.
[0013]
In the catalytic combustion apparatus and the control method thereof according to the present invention, the temperature of the supply chamber can be maintained at such a high temperature that back combustion does not occur even when the environment changes. For this reason, it is possible to provide a compact and low-cost catalytic combustion apparatus and control method that have good combustion efficiency and can make the most of the merits of catalytic combustion such as low noise and clean exhaust gas.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a catalytic combustion apparatus according to the present invention. In the catalyst combustion apparatus 1 of this example, liquid fuel 70 such as kerosene is vaporized in a vaporization chamber (supply chamber) 12 and then burned on a catalyst plate 20 disposed in front of the vaporization chamber 12. The catalyst plate 20 is a member made of metal or ceramic. For example, a metal having a honeycomb structure, lime aluminate-dissolved silica-titanium oxide, or the like is used. Metal or ceramic is a catalyst, or they become a carrier for a catalyst for combustion such as platinum, and catalytic combustion is performed when fuel vaporized at a predetermined temperature is supplied together with oxygen (air). Due to catalytic combustion, the catalyst plate 20 becomes high temperature, and infrared rays are emitted from the ceramic or metal catalyst plate. Infrared rays emitted from the front surface 21 of the catalyst plate 20 can be used for heating purposes. On the other hand, the infrared rays emitted from the rear surface 22 are used to heat the vaporizing chamber 12 and vaporize the liquid fuel 70 released to the vaporizing chamber 12.
[0015]
The vaporizing chamber 12 is a hollow space in which an outer shell (shell) 11 is formed of a heat-resistant material such as SUS430 and an aluminum-containing ferrite. Behind the vaporization chamber 12 are a fuel spray section 13 for spraying the liquid fuel 70 supplied from the fuel pump 7, a blower (blower) 15 for supplying outside air as combustion air 71, and a blower motor 15 a for driving the blower 15. Has been placed. The fuel spray section 13 of this example also has a function as a burner. When the vaporizing chamber 12 and the catalyst layer 20 are preheated, the liquid fuel sprayed from the burner 13 is ignited by the igniter 14 to form a flame. On the other hand, during the catalytic combustion, liquid fuel is sprayed from the burner 13 without igniting, thereby generating a mixed gas 72 in which the fuel 70 gasified in the vaporizing chamber 12 and the outside air 71 are mixed and supplied to the catalyst plate 20. .
[0016]
In the vaporization chamber 12, a porous radiation plate 30 made of SUS is disposed so as to face the catalyst layer 20 and face the catalyst layer 20 substantially parallel to the catalyst layer 20. The radiation plate 30 directly receives radiant heat from the rear surface 22 of the catalyst layer 20. Therefore, when catalytic combustion is started, the heat is received and the temperature becomes high, and the liquid fuel 70 supplied from the rear of the vaporizing chamber 12 is brought into contact with and promotes the vaporization. The radiation plate 30 may be a SUS surface sprayed with ceramic or made of ceramic.
[0017]
The catalytic combustion apparatus 1 of this example includes a flame sensor 40 that detects the flame of the vaporization chamber 12. As the flame sensor 40, an optical sensor that detects light having a wavelength emitted by a flame can be used. In this example, CdS (cadmium cell) is adopted. The flame sensor 40 is used to monitor whether a flame is normally generated from the burner 13 during preliminary combustion, and to detect whether backfire (back combustion) has occurred during catalytic combustion. .
[0018]
A vaporization chamber temperature sensor 41 is attached to the shell 11 of the vaporization chamber 12. The temperature sensor 41 uses a contact-type resistance temperature detector, and is detected and used as a representative value of the room temperature of the vaporizing chamber 12. Further, a temperature sensor 42 for detecting the outside air temperature is provided so that the temperature of the combustion air supplied to the vaporizing chamber 12 can be measured.
[0019]
The control device 50 of the catalytic combustion apparatus 1 of the present example controls the preliminary combustion and catalytic combustion using the outputs from these sensors 40 to 42. The control device 50 of this example is a microcomputer, and includes a sequence control unit 51 that controls the sequence of preliminary combustion and catalytic combustion, a pump control unit 52 that controls the operation of the fuel pump 7, and a blower control that controls the blower motor 15a. Unit 53, a flame detection unit 54 that determines the presence or absence of a flame based on the output from the flame sensor 40, a target value setting unit 55 that supplies a target rotational speed to the blower control unit 53, and a target value setting unit 55 A lookup table 56 referred to in FIG.
[0020]
The target value setting unit 55 has a first setting function 57 that sets the first target value 57t by the output of the outside air temperature sensor 42, and the second target value from the first target value by the output of the vaporizing chamber temperature sensor 41. A second setting function 58 for setting 58t and a third setting function 59 for setting the third target value 59t from the second target value by the output of the flame detection unit 54 are provided. Then, the blower motor 15a is controlled so that the third target value 59t becomes the target value Tb of the blower control unit 53, and the rotational speed of the target value Tb is obtained. As a result, the amount of outside air supplied to the vaporizing chamber 12 is reduced. Be controlled.
[0021]
FIG. 2 shows an example of the lookup table 56 referred to by the target value setting unit 55. In the look-up table 56 of this example, the values of five patterns P1 to P5 whose numerical values increase at a pitch of 50 or 100 to the ranges R1 to R8 are set. First, one of the ranges R1 to R8 is selected by the first setting function 57 according to the measured temperature θ1 of the outside air temperature sensor 42. Further, a dip switch 45 is connected to the control device 50, and one of the patterns P1 to P5 is selected according to the value of the dip switch 45. Therefore, the first target value 57t is determined by the output of the outside air temperature sensor 42.
[0022]
The dip switch 45 is manually set when the catalytic combustion apparatus 1 is installed at a certain location. For example, the value is changed depending on the altitude at which the catalytic combustion apparatus 1 is installed. When the altitude is high, the density of air becomes small, so that an appropriate pattern close to the pattern P5 having a high rotational speed as a whole is selected. Further, as the outside air temperature θ1 increases, the air density decreases. Therefore, when the outside air temperature θ1 is increased, a value of a range that is close to the range R8 having a high rotation speed in the selected pattern and is associated with the outside air temperature θ1 in advance is set as the first target value 57t.
[0023]
In the second setting function 58, when the value of the vaporization chamber temperature sensor 41 becomes equal to or lower than a preset setting value S1, the value of the same range R obtained by lowering the pattern P selected as the first target value 57t by one. Is set as the second target value 58t. the same range Even in the case of R, the look-up table 56 of this example is made so that the number of rotations is reduced by about 100 to 200 rpm by reducing the pattern P by one. Accordingly, the amount of outside air supplied to the vaporizing chamber 12 is reduced, and the condition is changed in a direction in which the temperature of the vaporizing chamber 12 is increased. On the other hand, if the value of the vaporization chamber temperature sensor 41 is larger than the set value S1, the first target value 57t is set as it is as the second target value 58t. The set value S1 varies greatly depending on the size of the vaporizing chamber 12, the thickness of the shell 11, the position measured as a representative temperature of the vaporizing chamber 12, and the like. In this example, the temperature of the lower surface of the shell 11, which is likely to change in temperature when the temperature of the vaporizing chamber 12 is lowered and reliquefied, is measured as a representative value of the vaporizing chamber 12, and a value around 200 ° C. is set. It is adopted as the value S1.
[0024]
In the third setting function 59, when a flame is detected by the flame detection function 54, a value having a larger range R in the same pattern P as the second target value 58t is set as the third target value 59t. Is done. In the same pattern P range By increasing R, the look-up table 56 of this example is made so that the rotational speed increases by about 50 to 100 rpm. Accordingly, the amount of outside air supplied to the vaporizing chamber 12 increases, the conditions are changed in a direction in which the temperature of the vaporizing chamber 12 decreases, and back combustion hardly occurs. The look-up table 56 of this example shows the difference in the number of rotations between the patterns P within a range that can be selected by the second setting function 58 and the third setting function 59 when the first target value 57t is determined. Is made larger than the difference in rotational speed between the ranges R. Therefore, from the first state, when the pattern P is reduced by one by the second setting function 58 and the air volume is reduced, the temperature of the vaporizing chamber 12 is increased and back combustion occurs, the third setting is then performed. Even if the range 59 is increased by one by the function 59 and the air volume increases, the first state is not returned, and the same state is not cyclically repeated to become unstable.
[0025]
FIG. 3 is a flowchart showing an outline of the operation of the catalytic combustion apparatus 1. In step 81, the blower 15 is started to start the preliminary combustion. A table similar to the lookup table 56 is prepared for the rotation speed of the blower motor 15a, and is selected in accordance with the outside air temperature within a preset pattern. Next, in step 82, fuel 70 is sprayed from the burner 13 and ignited by the igniter 14, and preliminary combustion is started. When the temperature of the vaporizing chamber 12 reaches a predetermined temperature, the fuel pump 7 is stopped once in step 83, the flame is extinguished, and preparations for shifting to catalytic combustion (main combustion) are completed.
[0026]
In this combustion, in step 84, the target value setting unit 55 sets the target value Tb of the air volume, and in step 85, the blower control unit 53 drives the blower motor 15a so as to reach the target value Tb, and desired air is generated. The gas is supplied to the vaporizing chamber 12. Next, in step 86, if the conditions for starting the fuel pump 7 by the fuel pump control unit 52 are satisfied, the fuel pump 7 is started to start catalytic fuel. After the fuel pump 7 is stopped to complete the preliminary combustion, or after the fuel pump 7 is once stopped by the back combustion, if the conditions are satisfied, the catalytic combustion is started or restarted at step 88. On the other hand, when the condition is not satisfied, the process returns to step 84 and waits until the condition for resuming is satisfied. At this time, when the fuel pump 7 is stopped due to an error or a stop signal, the fuel pump 7 is stopped at step 87, and the sequence for stopping the catalytic combustion apparatus 1 is entered. Further, if the flame detection unit 54 determines that the flame is detected by the flame sensor 40 during the catalytic combustion, it is determined in step 89 that back combustion has occurred, and the fuel pump 7 is temporarily stopped in step 90. .
[0027]
FIG. 4 shows the process for setting the target value of the air volume in step 84 in more detail. In step 91, the outside air temperature θ1 is obtained from the outside air temperature sensor 42, and in step 92, the vaporizing chamber temperature θ2 is obtained from the vaporizing chamber temperature sensor 41. Next, at step 93, when the main combustion starts (initial) or when the outside air temperature θ1 fluctuates beyond the range of the lookup table 56 shown in FIG. The target value Tb set before that is temporarily canceled, and the first target value 57t selected from the outside air temperature θ1 and the DIP switch 45 is set as the target value Tb. Therefore, when the outside air temperature θ1 fluctuates, the target value Tb reflecting the vaporizing chamber temperature θ2 and back combustion described below is cleared, and the values of the pattern P and the range R corresponding to the outside air temperature θ1 are newly set as the target value Tb. Set. The target value Tb corresponding to the outside air temperature θ1 is basically the amount of air that provides stable catalytic combustion, and when the outside air temperature θ1 fluctuates, it returns to the basic setting, thereby leaving the basic setting. The main combustion can be prevented from continuing (main loop).
[0028]
When the vaporization chamber temperature θ2 falls below the set value S1 in step 95, the target value Tb set before is temporarily canceled by the second setting function 58 in step 96, and the vaporization chamber temperature is set. The second target value 58t when θ2 becomes equal to or less than the set value S1 is set as the target value Tb. Therefore, when the vaporization chamber temperature θ2 decreases, the target value Tb reflecting back combustion described below is cleared, and the value of the same range R is the target value Tb in the pattern P that is one smaller than the pattern P corresponding to the outside air temperature θ1. Set as For this reason, the control is performed in a direction in which the air volume decreases and the vaporization chamber temperature θ2 increases (low temperature loop).
[0029]
Further, when it is determined in step 97 that the flame has been generated by the flame detection unit 54, in step 98, the third setting function 59 sets the target value Tb in the pattern P that has been selected before. The value of the range R that is one greater than the range R selected before is set as the target value Tb. For this reason, the air volume is increased, the vaporization chamber temperature θ2 is lowered, and the back combustion hardly occurs (high temperature loop).
[0030]
Thus, according to the control method of the catalytic combustion apparatus 1 of this example, when the back combustion occurs, the fuel pump 7 is temporarily stopped to quickly eliminate the back combustion, and the air volume supplied to the vaporization chamber 12 is reduced. By raising it, it is possible to prevent the back combustion from occurring continuously. If the outside air temperature θ1 rises under that condition and the range R is increased by one, back combustion may not occur, but there is too much air flow for proper catalytic combustion, and the temperature of the vaporization chamber 12 decreases, There is a possibility that the power consumption for driving the blower 15 is excessively larger than necessary. On the other hand, in this example, when the outside air temperature θ1 fluctuates, the target value Tb increased by the back combustion is once reset to a value selected by the outside air temperature θ1. Thereafter, when back combustion occurs, a large value of the range R is automatically set as the target value Tb, and an air volume that does not cause back combustion is selected. Therefore, the minimum value that does not cause back combustion is always selected as the target value Tb of the air volume, and the temperature of the vaporization chamber 12 is maintained in an ideal state that is high enough to prevent back combustion. In addition, since the power consumed by the blower 15 is minimized under the conditions, the power consumed as auxiliary machine power can be suppressed.
[0031]
As described above, the catalytic combustion apparatus 1 of the present example varies the rotational speed of the blower motor 15a and corrects the output of the blower 15 based on the state of the vaporization chamber 12 via the control unit 50, thereby correcting the vaporization chamber 12. The temperature can be maintained optimally. That is, in the catalytic combustion apparatus 1 of this example, the condition of the vaporization chamber of the type heated by the radiant heat of the catalyst layer is optimized by controlling the air volume according to the control method or the combustion method described based on the above flowchart. It is possible to automatically control the state. Therefore, insufficient vaporization or backfire of the liquid fuel 70 in the vaporization chamber is prevented, and a catalytic combustion apparatus that can stably maintain safe and efficient catalytic combustion can be provided. For this reason, it is possible to provide a catalytic combustion apparatus that can make the most of the merits of catalytic combustion, which is flameless, has a low generation rate of harmful substances such as nitrogen oxides, and has less odor and noise.
[0032]
In the above description, an example of a control method using a program for setting a target value with reference to the lookup table 56 has been described. However, it is also possible to create a program so as to calculate the target value from a function having the outside air temperature θ1, the vaporizing chamber temperature θ2, or the number of back combustions as a variable, and such a program is included in the scope of the present invention. . Further, the control device 50 is not limited to a microcomputer-based one, and the control method of the present invention can be realized even with a wired logic type sequencer.
[0033]
Furthermore, in the above description, the present invention is described by taking as an example a catalytic combustion apparatus that uses a supply chamber for supplying fuel to the catalyst plate as a vaporizing chamber for vaporizing liquid fuel. However, the present invention is also applied to a catalytic combustion apparatus that mixes pre-gasified fuel with air in a supply chamber and supplies the gas to the catalyst plate, thereby preventing the occurrence of back combustion and efficiently performing the catalyst. A catalytic combustion apparatus capable of continuing combustion stably can be provided.
[0034]
【The invention's effect】
As described above, in the catalytic combustion apparatus and the control method thereof according to the present invention, the presence or absence of back combustion (backfire phenomenon) is monitored, and if there is back combustion, the air volume is increased to lower the temperature in the supply chamber, The supply chamber is maintained at such a high temperature that back combustion does not occur. Therefore, since the amount of air supplied to the supply chamber is controlled by detecting the actually generated back combustion, the temperature of the supply chamber can be more reliably maintained at such a high level that back combustion does not occur. During catalyst combustion, it is possible to avoid the occurrence of back combustion (backfire phenomenon) due to excessive increase in the temperature of the supply chamber.
[0035]
Moreover, it is possible to prevent the combustion of the catalyst from becoming unstable due to insufficient vaporization when the temperature of the supply chamber is excessively lowered and the liquid fuel is vaporized. Therefore, in a catalytic combustion apparatus that uses a supply chamber as a vaporization chamber for vaporizing liquid fuel by radiant heat from the catalyst layer or the catalyst plate as well as an apparatus for catalytic combustion of gasified fuel, a highly efficient and safe catalyst. It is possible to provide a catalytic combustion apparatus that can stably maintain combustion.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a catalytic combustion apparatus according to the present invention.
FIG. 2 is a diagram showing an example of a look-up table used for control of the catalytic combustion apparatus shown in FIG.
FIG. 3 is a flowchart showing control of the catalytic combustion apparatus shown in FIG. 1;
FIG. 4 is a flowchart showing processing for setting a target value of air volume.
[Explanation of symbols]
1 Catalytic combustion device
7 Fuel pump
11 Vaporization chamber shell
12 Vaporization room
13 Spraying device (burner)
14 Igniter
15 Blower
15a Blower motor
20 Catalyst layer (catalyst plate)
30 Radiant plate
40 Flame sensor
41 Temperature sensor for vaporization chamber
42 Outside temperature sensor
50 Control unit (control device)
70 Liquid fuel (kerosene)

Claims (7)

A catalyst plate for catalytic combustion of vaporized fuel;
A supply chamber for mixing and supplying fuel and outside air to the catalyst plate;
Control means for controlling the amount of outside air supplied to the supply chamber based on a target value;
Means for detecting a flame generated in the supply chamber ;
Means for measuring the temperature of the supply chamber;
Means for measuring the outside air temperature,
When the control means determines that a flame is detected during catalytic combustion, the control means increases the target value ,
When it is determined that the temperature of the supply chamber has decreased, the target value is decreased,
further,
If it is determined that the outside air temperature has fluctuated beyond a predetermined range, the target value before that time is once canceled, and a value associated with the outside air temperature in advance is obtained so that basically stable catalytic combustion is obtained at that outside air temperature. A catalytic combustion apparatus for setting the target value . In Claim 1, the said control means refers to the look-up table containing the value previously linked | related with external temperature, and when the temperature of the said supply chamber is lower than a setting value, with respect to the value previously linked | related with the external temperature Set the target value as the target value,
When a flame is detected, a catalytic combustion apparatus that sets, as the target value, a value added to a value associated with the outside air temperature in advance. 3. The lookup table according to claim 2, wherein the lookup table has a plurality of patterns of values associated with the outside temperature in advance.
Furthermore, the catalytic combustion apparatus which has a switch for selecting either of those patterns. A method for controlling a catalytic combustion apparatus that mixes vaporized fuel and outside air in a supply chamber and supplies the mixed fuel to a catalyst layer to perform catalytic combustion,
A step of controlling the amount of outside air supplied to the supply chamber based on a target value;
If it is determined that a flame has been detected during catalytic combustion, the step of increasing the target value ;
If it is determined that the temperature of the supply chamber has decreased, the step of decreasing the target value;
When it is determined that the outside air temperature has fluctuated beyond a predetermined range, the target value before that time is temporarily canceled, and a value associated with the outside air temperature is set in advance so that basically stable catalytic combustion can be obtained at that outside air temperature. and a step of setting the target value, the method. 5. The step of lowering the target value according to claim 4, wherein a lookup table including a value associated with an outside temperature in advance is referred to, and when the temperature of the supply chamber is lower than a set value, the temperature is associated with the outside temperature in advance. The value subtracted from the value is set as the target value,
In the step of raising the target value, the method refers to the look-up table, and when a flame is detected, a value added to the value associated with the outside air temperature in advance is set as the target value. A program of a program control device that controls a catalytic combustion device that mixes vaporized fuel and outside air in a supply chamber, supplies the mixture to a catalyst layer, and performs catalytic combustion,
By means of the program control device, a target value for the rotational speed of a blower for supplying outside air to the supply chamber is determined.
When it is determined that the flame is detected by the means for detecting the flame generated in the supply chamber during catalytic combustion,
When it is determined that the temperature of the supply chamber has been lowered by the means for measuring the temperature of the supply chamber,
If it is determined by the means for measuring the outside air temperature that the outside air temperature has fluctuated beyond a predetermined range, the target value before that time is once canceled, and the outside air is obtained in advance so that basically stable catalytic combustion is obtained at that outside air temperature. A control program that sets a value associated with temperature .   7. The program control device according to claim 6, wherein the program control device refers to a look-up table including a value associated with an outside temperature in advance, and if the temperature of the supply chamber is lower than a set value, the value associated with the outside temperature in advance. A program for setting, as the target value, a value added to a value previously associated with the outside air temperature when a flame is detected when the value subtracted by the above is set as the target value.

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