JP2003097893A - Heat recovering type heat accumulating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat recovering type heat accumulating device of high reliability and favorable efficiency which is compact, and which generates no water leak in an exhaust gas duct. SOLUTION: Gas from a compressed gas source (stream generating source) 1 is introduced through a pipe 7 to a heat exchanger 6 in the exhaust gas duct 4 in a furnace 2. This gas receives heat possessed by exhaust gas 5 and is heated, and it is erupted from an eruption part 9 provided in a tank 50 into liquid 12. Bubbles 13 generated at this time rise by buoyancy, where its stay time is elongated by a baffle plate 53 provided in the tank 50 to improve heat exchanging performance. The liquid 12 heated in these processes overflows from a pipe 52 to be transferred to a tank 10 adjoining it to be thermally stored there.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat treatment furnace, an electric furnace,
The present invention relates to a heat recovery type heat storage device that recovers and stores exhaust heat of exhaust gas generated from a heat exhaust device such as an engine.

[0002]

2. Description of the Related Art Conventionally, there is a heat recovery method using a partition type gas / gas heat exchanger, which uses a blower on the secondary side (heat recovery side) of a heat exchanger installed in high temperature exhaust gas. The air to be sent is sent to exchange heat to raise the temperature, and the heated air is used for heating, or hot water is further produced using a water / gas secondary heat exchanger to be used for hot water supply.

A heat pipe type heat exchanger is used as a heat exchanger to transfer the heat of combustion gas to one end of the heat pipe, transfer this heat to the other end of the heat pipe, and heat the water around it. It is known that the temperature is raised to store heat.

Further, heat exchange using direct contact between exhaust gas and liquid is disclosed in, for example, JP-A-4-244590.
And JP-A No. 11-337273.

[0005]

In the above-mentioned prior art, while water is passed through the secondary side, the temperature is raised to be changed to hot water, so that water scale adheres to the inner wall of the heat exchanger on the water side, resulting in heat exchange efficiency. The heat exchanger heats up and burns out to form holes, water may flow into the exhaust gas, and a steam explosion may occur.

Further, in the case of using the heat pipe, when the temperature of the exhaust gas is high, the vapor pressure of the working medium in the heat pipe increases and there is a risk that the heat pipe is pressure-ruptured.

Further, in the case of heat exchange using direct contact between the exhaust gas and the liquid, the exhaust gas is jetted directly into the liquid in the tank, so that the liquid is contaminated by mist and impurities in the exhaust gas.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a heat recovery type heat storage device which is small and compact and which is highly reliable and efficient.

[0009]

In order to solve the above problems, the present invention provides a heat recovery type heat storage device for transporting exhaust heat of exhaust gas from a heat exhaust device and storing the exhaust heat, and an exhaust duct for exhausting the exhaust gas. A heat exchanger provided inside, a compressed gas source or a steam generation source connected to the heat exchanger via an inlet pipe, and an end pipe of the outlet pipe of the heat exchanger, and stored in a tank And a jetting part placed in a liquid (water / oil, etc.) introduced into the heat exchanger from the compressed gas source (or the vapor generating source) to introduce the gas into the liquid from the jetting part. It is something to infuse.

Further, in the above structure, it is desirable to provide a nozzle having a small hole in the ejection portion.

Further, in the above-mentioned apparatus, it is preferable that a serpentine plate, a spiral screw, or the like is provided in the liquid in the tank, and gas is blown into the liquid in the plate or screw through the ejection portion.

Further, according to the present invention, a packing material is arranged on the upper part of the tank, and the liquid in the tank is supplied to the outer surface of the packing material to make it fall in the form of a falling liquid film. It is desirable to carry out direct contact heat exchange of the gas.

Further, in the present invention, in the heat exchange section in the exhaust gas, it is desirable to introduce the gas whose temperature has been raised into a separate gas / liquid heat exchanger to raise the temperature of the liquid.

Further, in the present invention, the vessel has a high-pressure vessel structure, the pressure in the vessel is increased by utilizing the pressure of the gas blown into the vessel, and the particle size of the bubbles generated when blowing into the liquid is reduced to heat. It is desirable to improve exchangeability.

Further, in the above, it is desirable that the compressed gas from the compressed gas source or the steam generation source is a gas or steam containing heated steam or mist.

Further, according to the present invention, in a heat recovery type heat storage device utilizing exhaust heat of exhaust gas, a heat exchanger is provided in an exhaust duct for exhausting the exhaust gas, and gas is introduced into the heat exchanger to rise. The gas is heated and the heat of the heated gas is stored and supplied to the heat utilization equipment.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an embodiment of the heat recovery type heat storage device of the present invention. The furnace 2 containing a heat source (combustion heat, etc.) 3 has an exhaust duct 4, and the exhaust duct 4
The exhaust gas 5 is discharged more. The exhaust gas 5 has a large amount of exhaust heat, and its recovery is important.

In FIG. 1, a heat exchanger 6 is provided in the exhaust duct 4 and a heat medium is introduced into the heat exchanger 6. As the heat medium, it is preferable to introduce gas (such as air) from the compressed gas source or the vapor generation source 1 through the pipe 7. Heat exchanger 6
The gas introduced into the inside is exhaust gas 5 from the outer surface of the heat exchanger 9.
The temperature is raised by receiving the heat of the water, and then the water is blown through the pipe 8 into the liquid (water, oil, etc.) 12 in the tank 50 which is smaller than the ejection portion 9. The bubbles 13 thus generated move upward in the liquid 12 by buoyancy. This small tank 50 is connected to a separately installed large tank 10 by a pipe 51 and a pipe 52 so as to form a circulation path. As the bubbles 13 rise, the liquid 12 around them also moves upward. The bubbles 13 and the liquid 12 are directly contacted and heat-exchanged, and the heat held by the bubbles 13 is transferred to the liquid 12.
As a result, the liquid 12 whose temperature has risen overflows from the upper pipe 52 and moves into the large tank 10. On the other hand, the low temperature liquid 12 in the lower portion of the large tank 10 enters the small tank 50 through the lower pipe 51 and repeats the same cycle as before. A large number of serpentine plates 53 are provided in this small tank 50.
The bubbles 13 rising from the lower part ascend by meandering by 53, so that it takes a long time to stay in the small tank 50, which promotes heat exchange with the liquid 12. In this embodiment, the baffle plates 53 are alternately arranged on the inner wall of the small tank 50.

FIG. 2 shows a block diagram of another embodiment of the baffle plate 53 in the small tank 50 of FIG. In this system, disc-shaped baffle plates 53 with holes 56 are installed on rods 55 at predetermined intervals and are inserted into a small tank 50. Since the holes 56 provided in the adjacent baffle plates 53 are staggered, the baffle plate 53 must be moved in order for the bubbles 13 to pass through the holes and move upward.
The liquid 12 in between must be moved almost horizontally, so that the residence time in the small tank 50 is long and the heat exchange property is enhanced.

FIG. 3 is a block diagram of a modified embodiment of the baffle plate in the small tank 50 of FIG. This is a disc-shaped baffle plate 53 with one side cut away. By arranging the cutout portions 57 of the adjacent baffle plates 53 alternately, the same effect as that of the embodiment of FIG. 2 can be obtained.

FIG. 4 is a block diagram of another embodiment of the heat recovery type heat storage device of the present invention. This is one in which a helical screw 53 provided on a rod 55 is installed in a small tank 50. The bubbles 13 ejected from the ejection part 9 into the liquid 12 rise while spirally swirling in the liquid 12 between the spiral screws 53. Therefore, the residence time of the bubbles 13 in the small tank 50 becomes long, and the heat exchange performance is improved. If a hole as shown in the embodiment of FIG. 2 is provided on the surface of the spiral screw 53, the liquid 12
Will move downward through this hole 56,
The rise of 13 and the fall of the liquid 12 are smoothly performed. The same effect can be obtained by providing a small cutout portion on the outer end portion of the spiral screw 53. In this embodiment, the compressed gas source (or steam generation source), the furnace, and the heat exchanger contained therein are omitted.

FIG. 5 is a block diagram of another embodiment of the heat recovery type heat storage device of the present invention. This is packed at the top of tank 10 46
A pump 42 is used to suck the liquid 12 in the lower part of the tank 10 through a pipe 16, and further, a pipe 43 and a manifold 45.
It is adapted to be sprayed from the discharge part 44 through. On the other hand, the high temperature gas in the pipe 8 is jetted upward from the small hole 9-a provided in the jet portion 9. The liquid 12 blown from the discharge part 44 descends downward while flowing down the outer surface of the packing material 46, and in the process of heat exchange between the liquid 12 and the high temperature gas moving from the lower part to the upper part. , The temperature of the liquid 12 rises. As the packing material 46 used in this embodiment, a plastic ball, a metal sphere, a ceramic sphere or the like, or an uneven plastic plate or the like is effective.

FIG. 6 is a block diagram of another embodiment of the heat recovery type heat storage device of the present invention. This is the heat exchange section that sucks the liquid 12 in the tank 10 from the pipe 16 by the pump 42 and the pipe 43.
It is introduced into the tank 48 and returned to the tank 12 from the discharge part 49. On the other hand, the high temperature gas introduced into the pipe 8 is introduced into the outer cylinder 47 which surrounds the heat exchange section 48. As a result, the high temperature gas and the liquid 12 passing therethrough are heat exchanged in the heat exchange section 48,
The temperature of the liquid 12 rises and drops into the tank 10 as droplets 12-a. This raises the temperature of the liquid 12 in the tank 10,
The heat of the exhaust gas is stored in the liquid 12.

In this embodiment, the gas / liquid heat exchange section 48 is used, but since this heat exchange section 48 is not directly installed in the exhaust gas, even in the case where there is a hole, there is an important heating part in the heat treatment furnace. It is possible to avoid the situation of steam explosion in the electric furnace.

FIG. 7 is a block diagram of another embodiment of the heat recovery type heat storage device of the present invention. In this, the tank 10 has a structure of a pressure resistant container, a pipe 61 is provided in a part of the tank 10, and a pressure adjusting valve is provided therein.
62 is provided. By adjusting the opening degree of the pressure adjusting valve 62, the resistance of the high temperature gas 63 supplied from the pipe 8 while escaping from the small hole 9-a of the ejection portion 9 through the liquid 12 to the outside of the pipe 61. Changes and the internal pressure in the tank 10 is adjusted to a desired pressure. When the pressure in the tank 10 is raised above the atmospheric pressure in this way, the size of the bubbles 13 rising in the liquid 12 is miniaturized, and the heat exchange property is improved. When the liquid 12 is evaporative like water, etc., the internal pressure of the tank 10 is increased to increase the temperature of the liquid 12 to a region where the vapor pressure is high and heat can be stored, thus increasing the heat storage capacity of the tank 10. it can.

In this embodiment, as a method of utilizing the heat of the liquid 12 having a high temperature in the tank 10, the liquid 12 is transferred to another portion through a pipe equipped with a valve and used after being taken out. . Also the liquid 12 decreases with this,
It is also preferable to supply the liquid from another via a pipe with a valve.

FIG. 8 is a block diagram of another embodiment of the heat recovery type heat storage device of the present invention. This is provided with a high-pressure container 70 separately from the tank 10, a pipe 61 is provided in a part of this, and a valve 62 is attached. The pipe 8 is also provided with a valve 64, and the ejection portion 9 attached to the other end is exposed to the liquid 12 in the tank 63. The role of this tank 70 and the heat exchange property are the same as those described in FIG. In this embodiment, the large tank 10 and the high-pressure tank 70 are connected by a pipe 65 with a valve 66, and a separate pipe 67 with a valve 68 is attached to the tank 70 and the other end of the tank 10 is attached. It is facing the upper part. The hot gas 70 is ejected from the pipe 8 from the ejection part 9 into the liquid 12 in the tank 70 to exchange heat, and then the liquid 12 in the tank 70 is elevated while being discharged to the atmosphere through the pipe 61 and the valve 62. Heat to temperature. Then, this high-temperature liquid 12 is placed in a large tank 10
Perform the following operations to move it inside. When the valve 68 attached to the pipe 67 is opened, the internal pressure in the tank 70 increases
The liquid level of the liquid 12 in the 70 is pushed down, and along with this, the bath 70
The liquid 12 therein is transferred into the tank 10. When the desired amount of liquid 12 has been transferred to the tank 10 side, the valve 68 is closed. Also pipe
Fully open the valve 62 attached to 61 to open to the atmosphere. If necessary, the valve 64 attached to the pipe 8 is closed to stop the supply of the high temperature gas 63. Then, while opening the valve 66 attached to the pipe 65, the liquid 12 in the tank 10 is transferred from the tank 10 side to the tank 70 side by utilizing the head difference. When the predetermined liquid 12 is accumulated in the tank 70, each valve is returned to the original state and a high temperature gas is supplied from the pipe 8 into the tank 70 to restart heating. In this embodiment, if a partition plate 69 is provided in the liquid 12 in the tank 10 as shown in the drawing to separate the high temperature liquid 12 and the low temperature liquid 12-a, the heat exchange efficiency is increased.

FIG. 9 is a block diagram of another embodiment of the present invention. This is an embodiment in the case of recovering the exhaust heat of the heat treatment furnace to store the heat. This heat treatment furnace is a belt conveyor (made of iron)
A case is shown in which exhaust heat generated when a component 84 to be heat-treated such as annealing is placed and moved on 81 and heated to a predetermined temperature and then cooled is stored. parts
84 is mounted on a belt conveyor 81 which is moved by drive wheels 82 and 83 attached to a gantry 80, and moves from the left side to the right side in a furnace surrounded by a heat insulating cover 92. In the left half of the furnace surrounded by the cover 92, the components are heated to a high temperature by a radiant main burner (fuel is butane gas, LPG gas, etc.) 85. The radiant burner is a pipe-shaped burner that burns fuel in the pipe to heat the pipe, and heats the component 84 with radiant heat from the heated outer surface of the pipe. In this embodiment, the metamorphic gas (mixture of O2, CO2, H2, etc.) generated by the combustion of fuel in the pipe is taken out and introduced into a cooling device (not shown) to control a predetermined temperature (the dew point is controlled to a negative temperature). ) And introduce this modified gas (neutral gas) into the furnace surrounded by the cover 92 on the right side to prevent the component 84 from oxidizing. In such a radiant main burner, the amount of heat is insufficient, and the temperature control in the furnace may not be sufficient, but in this case, half of the main burner uses the radiant burner shown for producing the shift gas, The other half may be replaced with an electric heater. By such a heating method, when the heated component 84 moves to the space on the right side, the ambient temperature in the furnace is lowered by the cooler 86 that is cooled by water or the like, and the component 84 is appropriately cooled at the outlet. It The component 84 drops to the lower part at the end of the furnace, and a bucket 93 is prepared under this, and is stored in the bucket 93. By such a process, the heat treatment of the component 84 is completed, but in order to prevent the oxidizing air from entering the furnace surrounded by the cover 92 through the left and right open ports and oxidizing the component 84, Auxiliary burners 87 and 88 are provided on the cover 94 and the outlet cover 95 to form a frame curtain, and the fuel generated from the auxiliary burners 87 and 88 is burned by the oxidizing air to prevent oxygen from entering. However, since exhaust heat is discharged from the flues 89 and 90 and the chimney 91 connected to the flues 89, it is important to recover this heat. In this embodiment, the inlet cover 94,
The heat exchanger 6 of the present invention is provided in the outlet cover 95,
Gas is introduced into the inside from the pipe 7, and then the pipe 8
A gas is blown into the liquid 12 in the tank 10 via. As a result, the waste heat is stored in the liquid 12. This heat is effectively used as room heating and washing water when desired. In this embodiment, since gas is introduced into the heat exchanger 6, even if the heat exchanger 6 is damaged, no water leak will occur and no steam explosion will occur. Therefore, no damage is caused to the part 84.

Although cold water is introduced into the cooler 86 inside the cover 92, the temperature rises due to the heat of the gas inside the cover 92, and this heat also needs to be recovered. In this embodiment, a pipe 105 with a valve 104 is branched and connected to the pipe 102, and the water whose temperature has risen is introduced into the tank 10 through the pipe 106 with the valve 107 or the pipe 108 with the valve 109.
It is used as residual heat of the liquid 12 when the bubble 13 of which the temperature has risen is blown into the liquid 12 therein to heat it.

Further, the cooler 86 is changed from a water cooling type to an air cooling type,
A gas (or steam) is introduced into the cooler 86 to recover heat, and then the gas (or steam) is blown directly into the tank 10 or is introduced into the pipe 7 and put into the heat exchanger 6 to further Heat to a high-temperature gas (or vapor) and tank 10
Even more effective when placed inside.

In this embodiment, the heat exchanger 6 for recovering heat has a flue 89, in addition to the inlet cover 94 and the outlet cover 95.
90 and 91 may be provided in the chimney.

FIG. 10 is a block diagram of another embodiment of the heat recovery type heat storage device of the present invention. This is a heat storage tank 110 containing a heat storage material 111 between the tank 10 and the heat exchanger 6 installed in the exhaust gas 5.
Is provided. The heat storage material 111 has, for example, a melting point of 3
A high temperature latent heat material such as sodium nitrate (NaNO3) having a latent heat of 173 kJ / kg at 10 ° C. is used, and heat exchangers 115 and 116 are installed therein. The gas whose temperature has risen in the heat exchanger 6 is pipe 8
It enters into the heat exchanger 115 through the and is discharged to the outside. The gas passing through the heat exchanger 115 passes through the wall of the heat exchanger 115 to store the heat storage material.
The heat storage material 111 is melted by heating the heat storage material 111. When heat is taken out, the heat (heat or air) held in the heat storage material 111 is passed through a separate heat exchanger 116 installed in the heat storage material 111 to the fluid, and the fluid is transferred into the tank 10. For this purpose, the valve 113 attached to the inlet pipe 112 of the heat exchanger 116 is opened to introduce the fluid into the heat exchanger 116, and the fluid is introduced into the tank 10 through the outlet pipe 114 from the ejection portion 9. In this way, the high-density high-temperature heat storage material 111 can store heat at any time when exhaust heat is discharged, and it can be taken out at a desired time and the high-temperature liquid 12 (hot water) can be stored in the tank 10.

The heat storage tank 110 accommodating the heat storage material 111 of the embodiment shown in FIG. 10 can be used for the pipe 8 for gas transportation shown in FIGS. 1, 4, 5, 6, 7, 8 and 9. Needless to say.

As described above, a gas / gas heat exchanger is provided in the exhaust gas, but compressed air (using a compressed air source for a factory, etc.) in the heat exchange passage on the secondary side (heat recovery side). ) Is introduced and heat is exchanged to raise the temperature of the liquid, so the heat exchange efficiency is good, there is no fear of burnout of the heat exchanger, steam explosion, pressure destruction, etc., and the liquid is contaminated by mist and impurities in the exhaust gas. Nothing.

In the above example, the gas is not air or nitrogen, and superheated steam generated from the boiler, steam containing fine liquid particles (mist), and steam obtained by reheating the drain water of the boiler are used. Is also advantageous in terms of cost and the like. Further, it is desirable in terms of efficiency and cost to use a gas having a residual pressure in a cascaded manner after once using it for rotating the machine tool. Further, it is desirable to fill the inside of the tank 10 with a latent heat storage type heat storage container and increase the heat storage amount in order to improve the efficiency.

[0036]

As described above, according to the present invention, gas is introduced into the heat exchanger in the exhaust duct to raise the temperature, and the heat of the heated gas is stored and can be used. Thus, the device can be small and compact, and a highly reliable and efficient heat recovery type heat storage device can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a heat recovery type heat storage device of the present invention.

FIG. 2 is a configuration diagram of another embodiment of the baffle plate in the small tank of FIG.

FIG. 3 is a configuration diagram of a modified embodiment of the baffle plate in the small tank of FIG.

FIG. 4 is a configuration diagram of another embodiment of the heat recovery type heat storage device of the present invention.

FIG. 5 is a configuration diagram of another embodiment of the heat recovery type heat storage device of the present invention.

FIG. 6 is a configuration diagram of another embodiment of the heat recovery type heat storage device of the present invention.

FIG. 7 is a configuration diagram of another embodiment of the heat recovery type heat storage device of the present invention.

FIG. 8 is a configuration diagram of another embodiment of the heat recovery type heat storage device of the present invention.

FIG. 9 is a configuration diagram of another embodiment of the present invention.

FIG. 10 is a configuration diagram of another embodiment of the heat recovery type heat storage device of the present invention.

[Explanation of symbols]

1 ... Compressed gas source (steam generation source), 2 ... Furnace, 3 ... Heat source, 4 ... Exhaust duct, 5 ... Exhaust gas, 6 ... Heat exchanger, 7, 8 ... Pipe, 9 ...
Ejection part, 10 ... Tank, 12 ... Liquid, 13 ... Bubble, 14 ... Valve, 15
… Pressure gauge, 16… Suction pipe, 42… Pump, 43… Pipe,
44 ... Discharge part, 45 ... Manifold, 46 ... Packing material, 47 ...
Outer cylinder, 48 ... Heat exchanger, 49 ... Discharge part, 50 ... Tank, 51, 52 ... Pipe, 53 ... Snake plate, 54 ... Hole, 55 ... Rod, 56 ... Hole, 57 ... Notch, 61 ... Pipe , 62 ... Pressure control valve, 63 ... Gas, 64, 66,
68 ... valves, 65, 67 ... pipes, 69 ... partition plates, 70 ... tanks.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masako Mikio             Hitachinaka City, Ibaraki Prefecture 2520 Takaba             Ceremony Company Hitachi Ltd. Automotive equipment group F term (reference) 4K056 AA02 AA05 AA09 DA02 DA03                       DA04 DA15 DA27 DA29

Claims (6)

[Claims] 1. A pipe for transporting a gas from a compressed gas source or a steam generation source is connected to a heat recovery heat exchanger provided in an exhaust gas duct, and is connected to a pipe connected to the other end of the heat exchanger. The jetting part for jetting gas is connected to a tank containing a liquid, and a serpentine plate or a screw in the vertical direction is provided in the tank, and the tank provided separately from the tank and the tank are circulated. A heat recovery type heat storage device connected from two pipes to make 2. A pipe for transporting a gas from a compressed gas source or a vapor generation source is connected to a heat recovery heat exchanger provided in an exhaust gas duct, and is connected to a pipe connected to the other end of the heat exchanger. A jetting part for jetting gas is installed below the packing material in the tank containing the packing material, and a mechanism for spraying the liquid stored in the lower part of the tank from the discharge part to the upper part of the packing material using a pump is provided. Heat recovery type heat storage device. 3. A pipe for transporting a gas from a compressed gas source or a steam generation source is connected to a heat recovery heat exchanger provided in an exhaust gas duct, and the pipe outlet is connected to the other end of the heat exchanger. A heat recovery type heat storage system that is equipped with a mechanism that connects an outer cylinder and introduces the liquid in the tank separately provided through a pipe using a pump into the heat exchange section provided in the outer cylinder and returns it to the tank. apparatus. 4. A pipe for transporting a gas from a compressed gas source or a steam generation source is connected to a heat recovery heat exchanger provided in an exhaust gas duct, and is connected to a pipe connected to the other end of the heat exchanger. The gas jetting part is connected to a tank containing liquid, and a pipe with a valve for removing the gas is provided in a part of this tank, and the pressure in the tank is adjusted by changing the opening of this valve. A heat recovery type heat storage device designed to be enhanced. 5. The heat recovery type heat storage device according to claim 1, wherein the heat recovery heat exchanger is provided in an exhaust heat generation part of a heat treatment furnace for heat treating parts. . 6. A heat recovery system characterized in that a separate heat storage tank is thermally interposed in the pipe section after exiting the heat recovery heat exchanger according to any one of claims 1 to 5. Heat storage device.