JP2003279160A - Fluid heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with vacuuming a heating medium tank. <P>SOLUTION: A hot water boiler is formed by providing a combustion chamber 4 with a burner 5 to the lower part of the heating medium tank 14 in which a heating medium 15 is stored, and providing a heat transfer tube 10 to the upper part of the heating medium tank 14. The heating medium 15 is used as wax with a melting point equal to the desired temperature of hot water 9a and as suspension for water. When the heating medium 15 in the heating medium tank 14 is heated to the melting point of the wax by burning the burner 5 in the combustion chamber 4, the heating medium 15 is kept at the constant temperature during the solid-to-liquid phase transition of the wax. At this point, water is supplied to and runs through the heat transfer tube 10, and it is heated to the melting point of the wax and turns hot water 9a, and then it is collected. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid heating device used for heating a fluid to be heated such as a process fluid to a temperature of 100 ° C. or lower.

[0002]

2. Description of the Related Art Conventionally, 100% of water is used as a process fluid.
As a fluid heating device for heating hot water by heating to a temperature of ℃ or less, there is a hot water boiler that indirectly heats water via heat transfer water to produce hot water. One of them is a vacuum hot water boiler.

In such a vacuum hot water boiler, as shown schematically in FIG. 2, an inside of a lower portion of a heat transfer water storage tank (can body) 1 in which a heat transfer water 3 is enclosed so that a steam chamber 2 is formed in the upper part. , A combustion chamber 4 is provided so as to be submerged in the heat transfer water 3, a burner 5 is installed, a vacuum pump 6 is provided at the top of the heat transfer water storage tank 1, and a vacuum drawing line 7 having an opening / closing valve 8 is provided. And a heat transfer tube 10 as a heat exchanger that allows water 9 to be heated to flow from the outside at the upper position in the heat medium water storage tank 1 that serves as the steam chamber 2. As a configuration, in a state where the inside of the heat transfer water storage tank 1 is evacuated by the operation of the vacuum pump 6, the burner 5 is burned to heat the heat transfer water 3 through the wall surface of the combustion chamber 4, thereby The heat transfer water 3 in vacuum is heated to a temperature of 100 ° C. or lower, for example, Rapidly boils at 80 ° C., evaporated, under reduced pressure vapor generated by condensing on the surface of the heat transfer tube 10 causes filling the steam chamber 2, the heat transfer tubes 9
The heat water is exchanged with the water 9 flowing therethrough, and the hot water 9a heated to the temperature of the reduced pressure steam can be recovered from the outlet of the heat transfer tube 9. In addition, 11 is an exhaust port of the combustion chamber 4, 12 is a fire weir installed so as to face the burner 5 in the central portion of the combustion chamber 4, and 13 is a portion of the combustion chamber 4 behind the fire weir 12 that becomes a flue. Is a water pipe for heat transfer provided so as to pass through in the vertical direction.

As described above, in the vacuum hot water boiler, the heat transfer area can be reduced by utilizing the condensing heat transfer, and the temperature of the condensing region of the heat transfer water 3 under the reduced pressure is set to the control temperature. Even in the case of intermittently exchanging heat with the water 9 that is the heating target fluid, the temperature of the heat transfer water 3 does not change significantly, so that the hot water 9a that is always heated to a constant temperature can be manufactured. It has the characteristics of

[0005]

However, in the above-mentioned conventional vacuum hot water boiler, the inside of the heat transfer water storage tank 1 needs to be evacuated, and therefore equipment such as the vacuum pump 6 must be attached. There is a problem that the heat transfer water storage tank 1 needs to have pressure resistance against the atmospheric pressure acting from the outside.

Therefore, according to the present invention, it is possible to eliminate the need to evacuate the heating medium tank and to always heat the fluid to be heated to a constant temperature even when the fluid to be heated is intermittently heat-exchanged. It is intended to provide a device.

[0007]

In order to solve the above problems, the present invention provides a combustion chamber and a heat medium tank in contact with the combustion chamber,
A heat medium containing a phase change substance that undergoes a phase change at a required temperature of 100 ° C. or less under atmospheric pressure is housed in the heat medium tank, and a fluid to be heated is circulated from the outside in the heat medium tank. A heat exchange section for exchanging heat with the heat medium is provided.

When combustion is performed in the combustion chamber, the heat medium in the heat medium tank is heated through the wall surface of the combustion chamber, and the heat medium is
When the required temperature of 100 ° C. or less is reached, the phase change of the phase change substance contained in the heat medium is started, and the temperature of the heat medium is kept constant while the phase change substance undergoes the phase change. At this time, when the fluid to be heated is supplied to the heat exchange portion from the outside and circulated, the fluid to be heated is heated to the required temperature of 100 ° C. or lower and then collected.

Further, by adopting a constitution in which the phase change substance has a melting point at atmospheric pressure and a required temperature of 100 ° C. or less, the phase change of the phase change substance at the required temperature is between solid and liquid. Since it becomes a phase change, it is possible to eliminate the need to make the heat medium tank airtight, and it is possible to open to the atmosphere. Therefore, the pressure acting on the inside and outside of the heat medium tank can be reduced to reduce the heat medium tank. It is possible to reduce the strength required for the tank.

Further, the phase change material is a wax having a required temperature of 100 ° C. or lower under atmospheric pressure, and the heat medium is a suspension of the wax and water. Can be easily prepared, and the heating temperature of the fluid to be heated can be easily set by using waxes having different melting points.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows, as an embodiment of the fluid heating apparatus of the present invention, a case where the fluid heating apparatus is applied to a hot water boiler for producing hot water by heating water as a fluid to be heated.

Heat medium tank 1 having a vent port 20 at the top
4, a heat medium 15 described later is housed in the heat medium tank 14, and a combustion chamber 4 is provided at a lower position in the heat medium tank 14 so as to be submerged in the heat medium 15 and a burner 5 is provided. The exhaust port 11 of the combustion chamber 4 is connected to the exhaust pipe 17 rising along the heat medium tank 14, and the combustion exhaust gas 16 generated by the combustion of the burner 5 is circulated in the exhaust pipe 17. The exhaust pipe 17 is generated by the waste heat of the combustion exhaust gas 16.
Through the wall 14a that forms the boundary between the heat medium layer 14 and the heat medium layer 14
4 to heat the heat medium 15 inside, and further to the upper position of the heat medium tank 14 above the combustion chamber 4, to circulate water 9 as a heating target fluid from the outside so as to heat the water 9 and the heat medium. Heat transfer tube 1 as a heat exchanger so that 15 can exchange heat
0 (two sets in the figure) are arranged so as to be submerged in the heat medium 15, and a water supply line 18 for guiding water 9 from a water supply unit (not shown) to the inlet of the heat transfer tube 10 Heat transfer tube 10
At the outlet of the hot water recovery line 19 for recovering the hot water 9a produced by exchanging heat of the water 9 with the heat medium 15.
Connect each.

The heat medium 15 has a phase change materia that undergoes a phase change under atmospheric pressure at a required temperature lower than 100 ° C. corresponding to the temperature of the hot water 9a to be produced.
For example, a suspension (suspension) of wax, which is a phase change substance having a melting point of 60 ° C., and water is prepared and used.

Further, a temperature controller 21 is installed at the upper end of the heat medium tank 14. The temperature control device 21 includes a heating medium tank 1
4 detects the temperature of the heat medium 15 in the fuel cell 4 and, when the detected temperature exceeds the melting point of the wax contained in the heat medium 15, adjusts the flow rate provided in the fuel supply line 22 connected to the burner 5. The valve 23 is closed to stop the supply of the fuel 24 to the burner 5 to stop the combustion, and when the detected temperature becomes lower than the melting point of the wax, the flow rate adjusting valve 23 is opened to open the burner 5. To fuel 24
Is supplied to restart combustion.

At the position of the exhaust port 11 side of the combustion chamber 4,
A water tube 13 for heat transfer is provided so as to penetrate the combustion chamber 4 in the horizontal direction.

In the case of producing the hot water 9a using the hot water boiler having the above structure, first, when the fuel 24 is supplied to the burner 5 and burned, the combustion heat causes the combustion heat to pass through the wall surface of the combustion chamber 4,
Further, the heat medium 15 in the heat medium tank 14 is heated via the wall 14a by the waste heat of the combustion exhaust gas 16 flowing through the exhaust pipe 17. When the temperature of the heat medium 15 is heated to the melting point of the above-mentioned wax as a constituent, that is, 60 ° C., melting of the wax is started, and thereafter, until all the waxes are melted, The temperature will be kept constant. At this time, when the water 9 introduced from the water supply portion through the water supply line 18 is supplied to the heat transfer tube 10, the water 9 reaches the melting point of the wax of 60 ° C. while passing through the heat transfer tube 10 from the inlet to the outlet. Since heat is exchanged with the held heat medium 15 through the tube wall of the heat transfer tube 15, the water 9 has a temperature of 60 ° C.
The hot water 9a is heated up to
a is recovered through the hot water recovery line 19.

In the above, when the burner 5 continues to burn and all the wax in the heat medium 15 is melted, the temperature of the heat medium 15 rises above the melting point of the wax, 60 ° C., When this temperature rise is detected by the temperature control device 21, the combustion of the burner 5 is stopped, so that further heating is not performed, so that the solidification of the wax in the heating medium 15 is started, and then the heating medium is started. The temperature of the heating medium 15 is kept constant at the required temperature which is the melting point of the wax until all the wax in 15 solidifies. After that, when all the wax in the heat medium 15 is solidified, the temperature of the heat medium 15 becomes lower than the melting point of the wax. This temperature decrease is detected by the temperature control device 21 and the burner 5 burns. Is restarted, wax melting will start again,
By repeating the melting and solidification of the wax, the temperature of the heat medium 15 can be kept constant at the required temperature. Therefore, even when the water 9 is supplied from the water supply unit to the heat transfer tube 10 intermittently, the hot water 9a having a constant temperature heated to the required temperature is manufactured and collected.

As described above, according to the hot water boiler as the fluid heating apparatus of the present invention, since the heat medium 15 can be easily maintained at a constant temperature, the water 9 as the fluid to be heated is intermittently supplied. Even if there is, it is possible to produce and collect the hot water 9a heated to the required temperature at a constant temperature. At this time, since it is not necessary to make the heating medium tank 14 into a vacuum, the heating medium in the conventional vacuum hot water boiler is used. Equipment such as the vacuum pump 6 required for making the inside of the water storage tank 1 vacuum can be eliminated, and the heat medium tank 14 does not need to have a structure capable of withstanding atmospheric pressure from the outside.

Further, since the heat medium 15 is composed of wax, which is a phase change substance having a melting point at the above-mentioned required temperature, and water, the wax will melt or solidify at the above-mentioned required temperature. Since the phase change in the case is performed between the solid and the liquid, it is not necessary to make the heat transfer medium tank 14 airtight, and therefore the vent port 20 allows the heat transfer medium tank 1 to be heated.
If 4 is exposed to the atmosphere, even if the volume changes when the wax melts or solidifies, it is possible to eliminate the risk that the pressure of the gas acts in the inward and outward directions of the heat medium tank 14, and thus the heat medium tank The pressure acting on 14 can be reduced, and the strength required for the heat medium tank 14 can be reduced.

Furthermore, the heating medium 15 can be easily prepared by dispersing a wax having a melting point at a required temperature in water, and the heating temperature of the hot water 9a can be adjusted by selecting a wax having a different melting point and using it as a raw material. It becomes possible to set easily.

It should be noted that the present invention is not limited to the above-described embodiment, and in the above description, the combustion chamber 4 is provided inside the heat medium tank 14, but the burner 5 in the combustion chamber 4 is shown. If the heat medium 15 stored in the heat medium tank 14 can be heated by the combustion of the heat medium tank 14, the heat medium tank 14 and the combustion chamber 4 can be arranged such that the heat medium tank 14 is provided adjacently in the vertical and horizontal directions of the combustion chamber 4. The heat medium 15 may be determined as
Although the suspension composed of wax and water is shown, if the hot water 9a contains a phase change substance that undergoes a phase change at a desired heating temperature, the phase change substance may be used alone as the heat medium 15. As the change substance, the heat medium tank 14
It has been shown that a substance that undergoes a phase change between a liquid and a gas may be adopted if the vent port 20 is not provided in the above, and a case where the substance is applied to a hot water boiler as a fluid heating device. As a matter of course, the present invention can be applied to a fluid heating device for heating any fluid other than water, such as oil or gas, and various changes can be made without departing from the scope of the present invention.

[0023]

As described above, according to the fluid heating apparatus of the present invention, the following excellent effects are exhibited. (1) A combustion chamber and a heat medium tank in contact with the combustion chamber are provided, and the heat medium tank contains a heat medium containing a phase change substance that undergoes a phase change at a required temperature of 100 ° C. or less under atmospheric pressure. In addition, since the heat exchange part for circulating the fluid to be heated from the outside to exchange heat with the heat medium is provided in the heat medium tank, the heat medium is set to the phase change temperature of the phase change substance. Since the fluid to be heated can be easily maintained at a constant temperature, the fluid to be heated can be always heated to a constant temperature even when the fluid to be heated is intermittently supplied to perform heat exchange. Further, at this time, since it is not necessary to make the heat medium tank vacuum, it is not necessary to use equipment such as a vacuum pump which is required to make the heat medium water storage tank vacuum in the conventional vacuum hot water boiler. As well as
The heat medium tank does not need to be structured to withstand the atmospheric pressure from the outside. (2) By making the phase change substance a substance whose melting point at atmospheric pressure is the required temperature of 100 ° C. or lower,
Since the phase change of the phase change substance at the required temperature is a phase change between a solid and a liquid, it is possible to eliminate the need to make the heat medium tank airtight, and to open to the atmosphere, It is possible to reduce the pressure applied to the inside and outside of the heat medium tank to reduce the strength required for the heat medium tank. (3) The phase change material is a wax having a required temperature of 100 ° C. or lower at atmospheric pressure, and the heat medium is
By using the above suspension of wax and water, the heat medium can be easily prepared, and the heating temperature of the fluid to be heated can be easily set by using waxes having different melting points. be able to.

[Brief description of drawings]

FIG. 1 is a schematic sectional side view showing an embodiment of a fluid heating device of the present invention.

FIG. 2 is a cut side view schematically showing an example of a conventional vacuum hot water boiler.

[Explanation of symbols]

4 Combustion chamber 5 burners 9 Water (fluid to be heated) 14 Heat transfer tank 15 heat medium 10 Heat transfer tube (heat exchange section)

Claims (3)

[Claims] 1. A heat medium comprising a combustion chamber and a heat medium tank in contact with the combustion chamber, the heat medium tank containing a phase change substance that undergoes a phase change at a required temperature of 100 ° C. or less under atmospheric pressure. And a heat exchanging unit for allowing the fluid to be heated to flow from the outside to exchange heat with the heat medium in the heat medium tank. 2. The fluid heating device according to claim 1, wherein the phase change substance is a substance having a required temperature of 100 ° C. or lower at a melting point under atmospheric pressure. 3. A wax having a melting point of 100 ° C. or lower at atmospheric pressure as the phase change substance, and
The fluid heating device according to claim 2, wherein the heat medium is a suspension of the wax and water.