JP2001272031A - Heat exchanger and fuel reforming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately stably heat a fluid to be heated and, at the same time, to detect the abnormal heat-exchanging state between a heating fluid and the fluid to be heated. SOLUTION: A plurality of temperature sensors 51-58 is installed to a heat exchanger 30 which vaporizes the fluid to be heated maintained in a liquid state by using the heat obtained by burning fuel sprayed from an injector 28 on a combustion catalyst and the surface level of the fluid in the exchanger 30 is calculated based on the temperatures detected by the sensors 51-58. When the calculated surface level does not fall within an appropriate range, the heat- exchanging state is controlled by driving and controlling a blower 26 which supplies air and a fuel pump 24 which supplies the fuel so that the surface level may fall within the appropriate range. Therefore, the fluid to be heated can be vaporized efficiently and stably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a fuel reformer, and more particularly, to a heat exchanger and a hydrocarbon fuel for performing heat exchange between a heating fluid and a fluid to be heated in both gas and liquid phases. The present invention relates to a fuel reformer for reforming a fuel gas into a hydrogen-rich fuel gas.

[0002]

2. Description of the Related Art Conventionally, as this type of heat exchange device, there has been proposed a so-called catalytic combustion heating device for heating a fluid to be heated by burning fuel using a catalyst (for example, Japanese Patent Application Laid-Open No. 5-223201). Gazettes). The catalytic combustion heating device has a heating fluid flow path carrying a catalyst for burning fuel on the surface thereof, and a heated fluid flow path arranged to be heat-exchangeable with the heating fluid flow path, and supplies the heating fluid flow path to the heating fluid flow path. The fluid to be heated is heated using the heat obtained by burning the fuel on the catalyst.

[0003]

However, in such a catalytic combustion heating device, the fluid to be heated is heated by the heat obtained by burning the fuel in the heating fluid flow path. In many cases, it is more difficult to heat a desired amount of the fluid to be heated to a desired temperature than to heat the heated fluid. In the catalytic combustion heating device, the combustion of fuel occurs in a wide portion of the heating fluid flow path, and depending on the temperature distribution of the heating fluid flow path, heat exchange with the fluid to be heated may not be sufficiently performed, or overheating may occur. In some cases.

[0004] It is an object of the present invention to heat a fluid to be heated more appropriately. Another object of the present invention is to improve the responsiveness and stability of heat exchange. Still another object of the present invention is to detect an abnormality in a heat exchange state between a heating fluid and a fluid to be heated. An object of the fuel reformer of the present invention is to vaporize a reforming raw material more appropriately. Another object of the fuel reformer of the present invention is to improve the responsiveness and stability of vaporization of a reforming raw material.

The applicant has proposed a catalytic combustion heating apparatus for controlling the flow rate of a fluid to be heated based on the temperature of the fluid to be heated, as a solution to a part of the above-mentioned problem (Japanese Patent Application No. Hei 10-214,878). No. 9-306556).

[0006]

Means for Solving the Problems and Their Functions and Effects The heat exchange device and the fuel reformer of the present invention employ the following means in order to achieve at least a part of the above objects.

A heat exchange device according to the present invention is a heat exchange device for exchanging heat between a heating fluid and a fluid to be heated in both gas and liquid phases, wherein the heat exchange device performs heat exchange between the heating fluid and the fluid to be heated. Exchanging means, liquid level detecting means for detecting the liquid level of the fluid to be heated inside the heat exchanging means, and controlling a heat exchange state in the heat exchanging means based on the detected liquid level. The gist is to provide a heat exchange control means.

In the heat exchange apparatus according to the present invention, the heat exchange control means includes a heat exchange unit for exchanging heat between the heated fluid and the heated fluid detected by the liquid level detecting means. The heat exchange state in the heat exchange means is controlled based on the surface position. According to the heat exchange device of the present invention, since the heat exchange state is controlled by the liquid level of the fluid to be heated, it is possible to cope with a shortage or excess of the fluid to be heated, and to cope with a load fluctuation. Stable heat exchange can be performed with good responsiveness.

In the heat exchange apparatus of the present invention, the liquid level position detecting means includes a temperature distribution detecting means for detecting a temperature distribution of the heat exchanging means, and the liquid level position based on the detected temperature distribution. And a liquid level position estimating means for estimating the liquid level. When the pressure is constant, the boiling point of the substance is specified, so that the liquid level position can be estimated based on the temperature distribution of the heat exchange means. In the heat exchange device according to the aspect of the present invention, the temperature distribution detecting means may be means for detecting temperatures at a plurality of points of the heat exchange means.

[0010] In the heat exchange device of the present invention, the heat exchange control means may be means for controlling the liquid level to be within a predetermined height range.
In this case, more stable heat exchange can be performed.

Further, in the heat exchange apparatus according to the present invention, the heat exchange control means controls a flow rate of the heating fluid and / or a flow rate of the fluid to be heated to be supplied to the heat exchange means based on the liquid surface position. It can also be a means to perform.

Alternatively, in the heat exchange device of the present invention,
The heat exchange means has a heating fluid flow path that carries a combustion catalyst that burns fuel on the surface, and a heated fluid flow path that can exchange heat with the heating fluid flow path, wherein the heating fluid is composed of fuel and air. The fuel may be a mixed gas of combustion gas, unburned fuel, and air when the fuel is burned by the combustion catalyst when supplied to the heating fluid flow path. This makes it possible to reduce the size and efficiency of the device as compared with a device that holds a predetermined amount of the heating fluid. In the heat exchange device according to the aspect of the present invention, the heat exchange control means may be a means for controlling supply amounts of fuel and air supplied to the heating fluid flow path.

Further, in the heat exchange device of the present invention, the heat exchange control means includes a gradient detection means for detecting a gradient of the liquid level in the heat exchange means, and a gradient of the liquid level detected. The heat exchange state may be controlled based on the gradient. This way,
More stable heat exchange can be performed. In the heat exchange device of this aspect, the heat exchange control means may be means for controlling the gradient of the liquid level position to be within a predetermined gradient range. In the heat exchange apparatus according to the aspect of the present invention, which includes a gradient detection unit and the heating fluid is a mixed gas of combustion gas, unburned fuel, and air when the fuel is burned by the combustion catalyst, the heat exchange control unit includes: A means for controlling a ratio of fuel and air supplied to the heating fluid flow path may be used.

In addition, in the heat exchange device of the present invention,
Abnormality detection means for detecting an abnormality in the heat exchange state based on the liquid surface position detected by the liquid surface position detection means; and warning output means for outputting a warning when the abnormality is detected. Can also. In this case, it is possible to quickly cope with the abnormality in the heat exchange state.

A fuel reforming apparatus according to the present invention is a fuel reforming apparatus for reforming a hydrocarbon-based fuel into a hydrogen-rich fuel gas, wherein a reforming raw material comprising the hydrocarbon-based fuel and water is used. An evaporating section for evaporating, and a reforming section for reforming the vaporized reforming material to the fuel gas, wherein the evaporating section exchanges heat with the reforming material as the fluid to be heated. The gist of the present invention is a heat exchange device according to an aspect of the present invention.

According to the fuel reformer of the present invention, the heat exchange device of the present invention is used as an evaporator for evaporating a reformed raw material composed of a hydrocarbon fuel and water, so that the reformed raw material can be used. It can be vaporized stably.

In such a fuel reformer of the present invention,
The hydrocarbon-based fuel may be methanol.

[0018]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram schematically showing the configuration of a heat exchange device 20 according to one embodiment of the present invention. The heat exchange device 20 according to the embodiment receives an injector 28 that sprays fuel supplied from a fuel tank 22 by a fuel pump 24 and mixes the fuel with air supplied by a blower 26, and a mixed gas of fuel and air. The fuel in the mixed gas is combusted by the combustion catalyst to obtain heat to obtain a liquid to be heated from a heated fluid tank 42 which stores a liquid to be heated (for example, a reforming raw material composed of methanol and water and other liquids). The heat exchanger 30 includes a heat exchanger 30 that heats and evaporates the fluid to be heated supplied by the heating fluid pump 44, and an electronic control unit 60 that controls the entire apparatus.

FIG. 2 is a configuration diagram schematically showing the structure of the heat exchanger 30. As shown in the figure, the heat exchanger 30 has a corrugated heated fluid flow path member 3 having open ports at the top and bottom in the figure.
2 and a fuel flow path member 34 having corrugated plates having open ports on the left and right in the figure are alternately laminated. A combustion catalyst for burning fuel,
For example, a platinum catalyst or the like is carried, and the fuel burns on the combustion catalyst when flowing through the fuel flow path member 34. Since the heated fluid flow path member 32 and the fuel flow path member 34 are alternately laminated, the heated fluid flowing from the vertically lower side to the upper side in the heated fluid flow path member 32 is supplied to the fuel flow path member 34 from the left side. It exchanges heat with the combustion gas flowing to the right side, and is heated and vaporized.

As shown in FIG. 1, the mixed gas obtained by spraying the fuel by the injector 28 and mixing it with the air flows in a zigzag manner by two connecting pipes 36 and 37 attached to the heat exchanger 30, and the exhaust gas pipe It is discharged from 38. On the other hand, the liquid to be heated supplied to the heated fluid inlet 46 by the heated fluid pump 44 is vaporized by heat exchange by the heat exchanger 30 and sent out from the apparatus through the vapor outlet pipe 48.

The heat exchanger 30 includes four temperature sensors 5 in the vertical direction on the left side in FIG. 1 and four temperature sensors 5 in the vertical direction on the right side.
1 to 58 are provided so that the temperatures T1 to T8 of the respective parts in the heat exchanger 30 can be detected.

The electronic control unit 60 is configured as a microprocessor mainly including a CPU 62, and includes a ROM 64 storing a processing program, a RAM 66 temporarily storing data, and an input / output port (not shown). Prepare. The temperatures T1 to T8 from the temperature sensors 51 to 58 are input to the electronic control unit 60 via input ports. In addition, the electronic control unit 60 supplies the fuel pump 24, the blower 26, the heated fluid pump 4
A drive signal to the indicator 4 and a lighting signal to the indicator 70 are output via the output port.

Next, the operation of the heat exchanger 20 of the embodiment configured as described above will be described. FIG. 3 is a flowchart illustrating an example of a heat exchange control routine executed by the electronic control unit 60 of the heat exchange device 20 according to the embodiment. This routine is performed at predetermined time intervals (for example, immediately after the heat exchange device 20 of the embodiment is started and enters a steady operation state).
(Every 100 msec).

When the heat exchange control routine is executed, the CPU 62 of the electronic control unit 60
1 to 58, the temperature T of each part of the heat exchanger 30
1 to T8 are read (step S10).
0). Then, based on the read temperatures T1 to T8, the liquid surface positions (liquid surface heights) H1 and H2 of the fluid to be heated in the heat exchanger 30 are calculated (step S102). The liquid level height H1 is calculated by the proportional distribution from the height of the temperature sensor that detects the temperature using the temperature immediately above and below the boiling point of the fluid to be heated among the read temperatures T1 to T4. , The liquid level height H2 depends on the read temperatures T5 to T8.
From the same way. FIG. 4 shows an example of how the liquid level heights H1 and H2 are calculated. In the figure, Ha to Hd of the height axis
Are temperature sensors 51-54 and temperature sensors 55-58
From the heated fluid inlet 46 is shown. Also,
In the figure, black circles indicate the temperatures T1 to T4 detected by the temperature sensors 51 to 54, and white circles indicate the temperatures T5 to T8 detected by the temperature sensors 55 to 58. Assuming that the boiling point of the fluid to be heated is Te, the liquid level height H1 is the height Hc at which the temperature sensor 53 that detects the temperature T3 immediately above the boiling point Te is detected and the temperature T4 immediately below the boiling point Te is detected. The liquid level height H2 is calculated using the height Hd at which the temperature sensor 54 is located by the following equation (1), and the height Hb at which the temperature sensor 56 at which the temperature T6 immediately above the boiling point Te is detected is detected. And the height Hc at which the temperature sensor 57 that detects the temperature T7 immediately below the boiling point Te is calculated by the equation (2). The liquid level heights H1, H2 calculated in this way
Strictly speaking, the liquid level of the fluid to be heated may be different from the liquid level in the heat exchanger 30, but it can be considered as a sufficient value for use in controlling the apparatus. The liquid level estimated from the liquid level heights H1 and H2 thus calculated is shown as a liquid level A in the heat exchanger 30 in FIG.

[0025]

(Equation 1)

Subsequently, it is determined whether or not the calculated liquid level heights H1 and H2 are within an appropriate range (step S10).
4). Here, the appropriate range of the liquid level is determined by the apparatus, and in the embodiment, the height H of the temperature sensor 54 is set.
The range from the height slightly higher than d to the height Hb of the temperature sensor 52 was set. When the liquid level heights H1 and H2 are within an appropriate range, the liquid level gradient Δ is obtained by subtracting the liquid level height H1 from the liquid level height H2.
H is calculated (step S112), and the calculated liquid level gradient Δ
It is determined whether H is within an appropriate range (step S1).
14). Here, the appropriate range of the liquid surface gradient ΔH is determined by the apparatus.
20% of the distance between the sensor and the temperature sensor 58.
It is considered that the liquid surface gradient ΔH is preferably closer to 0 in order to obtain a uniform vapor of the fluid to be heated. When the liquid level gradient ΔH is within the appropriate range, the apparatus determines that the apparatus is operating within the appropriate range, and terminates this routine.

Returning to step S104, the liquid level H
When any one of H1 and H2 is not within the appropriate range, the liquid level heights H1 and H2 are compared with the thresholds HH and HL (steps S106 and S108). Here, the threshold value HH is set as an upper limit value of the liquid level heights H1 and H2, and the threshold value HL is set as a lower limit value of the liquid level heights H1 and H2. In the embodiment, the height Ha of the temperature sensor 51 is used as the threshold value HH, and the height Hd of the temperature sensor 54 is used as the threshold value HL. If either of the liquid level heights H1 and H2 is larger than the threshold value HH, it is determined that fuel combustion in the heat exchanger 30 is defective, and the misfire of the indicator 70 is turned on as a misfire alarm (step S118), and this routine ends. I do. If either of the liquid level heights H1 and H2 is smaller than the threshold value HL, it is determined that the fluid to be heated has not been supplied, and the emptying of the indicator 70 is turned on as an emptying warning (step S120). End the routine.

When the liquid level heights H1 and H2 are both between the threshold value HH and the threshold value HL, the supply amounts of fuel and air are controlled so that the liquid level heights H1 and H2 fall within appropriate ranges (step S1). S110). Specifically, the liquid level heights H1, H
If any one of the two values exceeds the appropriate range, it is determined that the fuel is insufficient, and control is performed to increase both the amount of fuel supplied by the fuel pump 24 and the amount of air supplied by the blower 26. If either H1 or H2 is below the appropriate range, it is determined that the fuel is excessive, and control is performed to reduce the amount of fuel supplied by the fuel pump 24 and the amount of air supplied by the blower 26. As described above, by setting the liquid level heights H1 and H2 of the fluid to be heated within the appropriate range, the fluid to be heated can be efficiently vaporized. After the control of the supply amounts of the fuel and the air amount, the process from step S112 is performed.

If the liquid level gradient ΔH is not within the proper range in step S114, it is determined that it is difficult to generate uniform vapor of the fluid to be heated by the heat exchanger 30, and the liquid level gradient ΔH is determined.
Control is performed to change the air-fuel ratio, which is the amount of fuel supplied with respect to the amount of air supplied, so that H falls within the appropriate range (step S116), and this routine ends. Specifically, the air-fuel ratio change control performs control to increase the amount of air supplied by the blower 26 when the liquid level gradient ΔH exceeds an appropriate range, and performs control by the blower 26 when the liquid level gradient ΔH falls below the appropriate range. This is performed by performing control to reduce the supply amount of air. By setting the liquid level gradient ΔH within the appropriate range, the fluid to be heated can be efficiently vaporized.

According to the heat exchanger 20 of the embodiment described above, the liquid surface heights H1 and H2 of the fluid to be heated are calculated based on the temperatures of the respective parts of the heat exchanger 30, and the liquid surface heights H1 and H2 are calculated. H
2, the heat exchange state in the heat exchanger 30 can be controlled. That is, by setting the liquid level heights H1 and H2 within an appropriate range and the liquid level gradient ΔH within an appropriate range, it is possible to efficiently and stably vaporize the fluid to be heated by heat exchange. Further, according to the heat exchange device 20 of the embodiment, the abnormality of the heat exchange state of the heat exchanger 30 can be detected by comparing the liquid level heights H1 and H2 with the threshold values HH and HL. Moreover, since the indicator 70 is turned on when an abnormality is detected, the operator can quickly respond to the abnormality.

In the heat exchanger 20 of the embodiment, the liquid level H
1, H2 and the control based on the liquid surface gradient ΔH are performed simultaneously, but the liquid surface heights H1, H2
And the control based on the liquid surface gradient ΔH may be separately performed. Further, only the control based on the liquid surface heights H1 and H2 is performed and the control based on the liquid surface gradient ΔH is not performed, or only the control based on the liquid surface gradient ΔH is performed and the control based on the liquid surface heights H1 and H2 is performed. The control may not be performed.

In the heat exchanger 20 of the embodiment, the liquid level heights H1 and H2 are calculated based on the temperatures T1 to T8 detected by the eight temperature sensors 51 to 58.
The liquid level heights H1 and H2 may be calculated based on the temperatures detected by the number of or more or seven or less temperature sensors. Further, the liquid level height in the heat exchanger 30 may be calculated or estimated by calculating or detecting the temperature distribution of the heat exchanger 30.

In the heat exchanger 20 of the embodiment, the liquid level H
If any one of H1 and H2 is larger than the threshold value HH, it is determined that a misfire has occurred, and if any of the liquid level heights H1 and H2 is smaller than the threshold value HL, it is determined that there is no air and the indicator 70 is turned on. Make a different decision, indicator 70
May be turned on, characters may be displayed on a liquid crystal display or the like instead of the indicator 70, or a warning may be issued by voice output.

Next, the heat exchange apparatus 20 of this embodiment is used to convert a hydrocarbon-based fuel into a hydrogen-rich fuel gas. An example in which the evaporator is used as an evaporator to evaporate will be described. FIG. 5 is a configuration diagram schematically showing the configuration of the fuel reformer 100 using the heat exchange device 20 of the embodiment as an evaporator. As shown in the figure, a fuel reforming apparatus 100 receives a reforming raw material composed of methanol and water as hydrocarbon-based fuels as a heated fluid, vaporizes this, and converts the vaporized reforming raw material into oxygen. Is provided with the heat exchange device 20 of the embodiment as an evaporating unit which mixes air as an oxygen-containing gas containing oxygen as a raw material gas.
A reforming unit 120 that receives a supply of raw material gas from 0 and generates a hydrogen-rich gas having a very low carbon monoxide concentration by a reforming reaction of the following equations (3) and (4) and an oxidation reaction of carbon monoxide: Reforming device 110 including CO reduction unit 130
And In the fuel reforming apparatus 100, in the heat exchange apparatus 20 of the embodiment, an air introduction pipe is provided in the steam outlet pipe 48, and the introduced air is mixed with the vaporized reforming raw material to form a raw material gas. And

CH ₃ OH + 2H ₂ O → 3H ₂₊ CO ₂ + H ₂ O + (CO) −49.5 kJ (3) CH ₃ OH + (１ ／) O ₂ → CO ₂ + 2H ₂ +189 kJ (4)

As shown in the figure, a reforming raw material in which methanol and water are mixed at a predetermined mixing ratio is first supplied to a reformer 110.
Is heated by the heat generated when the carbon monoxide is introduced into the CO reduction unit 130 and oxidizes the carbon monoxide. Then, the heated reformed raw material is sent to the heat exchange device 20 of the embodiment, and is vaporized by heat exchange with the combustion gas. The vaporized reforming raw material is used as a raw material gas for performing a reforming reaction by introducing air as an oxygen-containing gas containing oxygen at a predetermined ratio with respect to methanol. 120
And reforms the raw material gas into a hydrogen-rich reformed gas by the reforming reactions of the above formulas (3) and (4). This reformed gas is sent to the CO reduction unit 130, where the unreacted carbon monoxide is oxidized by oxygen in the air as the introduced oxygen-containing gas, and the hydrogen-rich fuel gas having a very low carbon monoxide concentration is obtained. It is said.

In the fuel reforming apparatus 100 configured as described above, the heat exchange device 20 of the embodiment efficiently and stably vaporizes the reformed material, so that the reformed material can be reformed efficiently and stably. it can.

In the fuel reformer 100 of the embodiment, air is introduced into the heat exchanger 20.
It is also possible to introduce air into the zero. Further, in the fuel reforming apparatus 100 of the embodiment, the reforming material as the fluid to be heated is heated by the CO reduction unit 130.
The heating may not be performed by the reducing unit 130.

In the fuel reforming apparatus 100 of the embodiment, methanol is used as the hydrocarbon fuel, but another hydrocarbon fuel may be used.

In the heat exchange apparatus 20 of the embodiment, an example is used in which the evaporating section of the fuel reforming apparatus 100 for reforming a hydrocarbon fuel is used. However, the fluid to be heated is supplied as a liquid and vaporized. Any fluid may be used as long as the fluid is delivered.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the scope of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically illustrating a configuration of a heat exchange device 20 according to an embodiment of the present invention.

FIG. 2 is a configuration diagram schematically showing a structure of a heat exchanger 30.

FIG. 3 is a flowchart illustrating an example of a heat exchange control routine executed by an electronic control unit 60 of the heat exchange device 20 according to the embodiment.

FIG. 4 is an explanatory diagram showing an example of a state of calculation of liquid level heights H1 and H2.

FIG. 5 is a configuration diagram schematically showing a configuration of a fuel reformer 100 using the heat exchange device 20 of the embodiment as an evaporator.

[Explanation of symbols]

Reference Signs List 20 heat exchange device, 22 fuel tank, 24 fuel pump, 26 blower, 28 injector, 30 heat exchanger, 32 heated fluid flow path member, 34 fuel flow path member,
36, 37 connecting pipe, 38 exhaust gas pipe, 42 heated fluid tank, 44 heated fluid pump, 46 heated fluid inlet, 48 steam outlet pipe, 51-58 temperature sensor, 60
Electronic control unit, 62 CPU, 64 ROM, 66
RAM, 70 indicator, 100 fuel reformer, 110 reformer, 120 reformer, 130 CO reduction unit.

Continued on the front page F term (reference) 3K005 AA10 AB12 AB19 AC05 BA05 BA06 CA01 DA01 3K065 TA19 TD04 TK02 TN01 4G040 EA02 EA03 EA06 EB03 EB14 EB43 EB44

Claims (13)

[Claims] 1. A heat exchange device for exchanging heat between a heating fluid and a fluid to be heated in both gas and liquid phases, comprising: a heat exchange means for exchanging heat between the heating fluid and the fluid to be heated; A liquid level position detecting means for detecting a liquid level position of the fluid to be heated inside the exchanging means; and a heat exchange controlling means for controlling a heat exchange state in the heat exchanging means based on the detected liquid level position. Equipped heat exchange equipment. 2. The liquid level position detecting means includes a temperature distribution detecting means for detecting a temperature distribution of the heat exchanging means, and a liquid level position estimating means for estimating the liquid level position based on the detected temperature distribution. The heat exchange device according to claim 1, comprising: 3. The heat exchange device according to claim 2, wherein said temperature distribution detecting means is means for detecting temperatures at a plurality of points of said heat exchanging means. 4. The heat exchange apparatus according to claim 1, wherein said heat exchange control means is means for controlling said liquid level to be within a predetermined height range. 5. The heat exchange control means for controlling a flow rate of the heating fluid supplied to the heat exchange means and / or a flow rate of the fluid to be heated based on the liquid level position. 4. The heat exchange device according to any one of 4. 6. The heat exchange device according to claim 1, wherein the heat exchange means includes a heating fluid flow path having a surface on which a combustion catalyst for burning fuel is carried, and a heating fluid flow path, Having a replaceable fluid passage to be heated, wherein the heating fluid is a combustion gas and an unburned gas when the fuel is burned by the combustion catalyst when fuel and air are supplied to the heating fluid passage. A heat exchange device that is a mixed gas of fuel and air. 7. The heat exchange apparatus according to claim 6, wherein said heat exchange control means is a means for controlling supply amounts of fuel and air supplied to said heating fluid flow path. 8. The heat exchange control means includes gradient detection means for detecting a gradient of the liquid level in the heat exchange means, and the heat exchange state is determined based on the detected gradient of the liquid level. The heat exchange device according to any one of claims 1 to 7, wherein the heat exchange device is a means for controlling the temperature. 9. The heat exchange device according to claim 8, wherein said heat exchange control means is means for controlling a gradient of said liquid level position to be within a predetermined gradient range. 10. The heat exchange apparatus according to claim 8, wherein the heat exchange control means is means for controlling a ratio of fuel and air supplied to the heating fluid flow path. 11. The heat exchange device according to claim 1, wherein abnormality detection means for detecting an abnormality in a heat exchange state based on a liquid surface position detected by the liquid surface position detection means, A heat output unit that outputs a warning when the abnormality is detected. 12. A fuel reformer for reforming a hydrocarbon-based fuel into a hydrogen-rich fuel gas, comprising: an evaporator for vaporizing a reforming raw material comprising the hydrocarbon-based fuel and water; 12. The heat generating apparatus according to claim 1, further comprising: a reforming unit configured to reform the vaporized reforming raw material into the fuel gas, wherein the evaporating unit exchanges heat with the reforming raw material as the fluid to be heated. A fuel reformer that is an exchange device. 13. The fuel reformer according to claim 12, wherein the hydrocarbon-based fuel is methanol.