JP2001289508A - High-temperature heat storage device and method for effectively utilizing thermal energy by utilizing reverse flow of heating medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-temperature heat storage device which can make the heating medium in a heat transfer tube flow reversely and a method for effectively utilizing thermal energy by utilizing the reverse flow of a heating medium. SOLUTION: The high-temperature storage device is provided with a water supplying means 10 on the inlet side of the heat transfer tube 5 constituting a heat storage tank 1 and a steam discharging means 20 on the outlet side of the tube 5 and the water supplying means 10 is provided with a reverse flow section 15 for the heating medium B in the tube 5 and a water supply pump 13 for a water supply pipe 11 connected between a water supply tank 12 and the heat transfer tube 5. The reverse flow section 15 is provided with an inlet valve 17 for a flow pipe 16 from the heat transfer tube 15 to the tank 19 and the steam discharging means 20 is provided with an outlet valve 22 for a discharge pipe 21 connected to the heat transfer tube 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature heat storage device mainly utilizing midnight power and a method for effectively utilizing heat energy by backflow of a heat medium.

[0002]

2. Description of the Related Art A conventional heat storage tank is disclosed in Japanese Patent Application Laid-Open No. 3-28210.
No. 1 and Japanese Patent Application Laid-Open No. Hei 5-256591, an electric heater and a heat transfer tube are provided, and a gap between the electric heater and the heat transfer tube is filled with a heat storage material. Was heated, and the water supplied to the heat transfer tube was heated to steam. That is, when steam is used, steam is immediately generated by supplying water to the heat transfer tube, so that it has a feature that it can sufficiently cope with use with a large load variation. In addition, since the apparatus can be operated only by electricity, the apparatus is more compact than those using oil or gas as a heat source, and is safe and easy to handle.

[0003]

The conventional heat storage tank has insufficient measures against the stoppage of the supply of steam. To solve this problem, for example, an inlet valve is provided on the inlet side of the heat transfer tube to supply the steam. Even if the inlet valve is closed at the time of shutdown and water supply to the heat transfer tube is stopped, the water remaining in the heat transfer tube is heated by the heat storage material even after the inlet valve is closed, and high-temperature water or steam (hereinafter, heat transfer tube High-temperature water or steam is referred to as a heat medium), and the supply is continued from the outlet for several seconds to several minutes, so that more heat medium than necessary is supplied.
There is a problem that the heat energy of the heated water remaining in the heat transfer tube is wasted. Conversely, an outlet valve is provided on the outlet side of the heat transfer tube, and when the supply of steam is stopped by closing the outlet valve, the water remaining in the heat transfer tube is heated by the heat storage material to become a heat medium, and the pressure in the heat transfer tube is reduced. When the pressure rises, the safety valve is opened and the heat medium is discharged to the outside, so that there is a problem that the heat energy of the heated water remaining in the heat transfer tube is wasted.

Accordingly, the present invention has been made in view of such problems of the prior art, and an object thereof is to provide a heat medium such as steam or high-temperature water remaining in a heat transfer tube of a heat storage tank. It is an object of the present invention to provide a high-temperature heat storage device that enables the backflow of heat, and a method of effectively utilizing heat energy by the backflow of the heat medium.

[0005]

According to a first aspect of the present invention, there is provided a high-temperature heat storage device comprising a water supply means on an inlet side of a heat transfer tube constituting a heat storage tank, and a heat transfer tube. Is provided with steam discharge means on the outlet side, and the water supply means is provided with a backflow part of the heat medium in the heat transfer tube. As a second aspect, in the high-temperature heat storage device of the first aspect, the water supply means is provided with a water supply pump in a water supply pipe connected between the water supply tank and the heat transfer pipe, and the reverse flow portion is provided in a flow pipe from the heat transfer pipe to the water supply tank. An inlet valve is provided, and the steam discharge means is provided with an outlet valve in a discharge pipe connected to the heat transfer pipe.

According to a third aspect of the present invention, there is provided a method for effectively utilizing heat energy by backflow of a heat medium, comprising: a water supply means at an inlet side of a heat transfer tube of a heat storage tank; and a steam discharge means at an outlet side of the heat transfer tube. The water supply means includes a water supply tank, a water supply pump, and a backflow part of the heat medium in the heat transfer pipe, and when the water supply pump is stopped, the heat medium in the heat transfer pipe can flow back from the backflow part to the water supply tank. Things.

[0007] Here, the heat storage tank refers to a heat storage tank that heats a heat storage material using electric power, particularly midnight power, and heats the water in the heat transfer tube with the heat storage material to obtain steam. Here, the water supply means means capable of supplying water to the heat transfer tube and backflow of the heat medium remaining in the heat transfer tube when the water supply pump is stopped. Here, the steam discharging means refers to a means for supplying the heat medium heated in the heat storage tank to the machinery using steam. Here, the inlet valve refers to a valve that allows the backflow of the heat medium, the outlet valve refers to a valve that allows the supply of steam, and both valves are manually operated.
Or it is an automatic type. Here, the heat medium is a general term for water, high-temperature water, and steam in the heat transfer tube.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of a high-temperature heat storage device according to the present invention will be described with reference to FIGS. 1 to 4. A water supply means 10 is provided at the inlet side of a heat transfer tube 5 constituting a heat storage tank 1. A steam discharge means 20 is provided on the outlet side of the heat transfer tube 5. The heat storage tank 1 is filled with a heat insulating material 7 between the outer casing 2 and the inner casing 3, and an electric heater 4 and a heat transfer tube are provided inside the inner casing 3. 5 and a heat storage material 6, a water supply means 10 is provided with a water supply pump 13 in a water supply pipe 11 connected between the water supply tank 12 and the heat transfer pipe 5, and a reverse flow of the heat medium B in the heat transfer pipe 5. Section 15 and the backflow section 15
An inlet valve 17 and a safety valve 18 are provided in a flow pipe 16 from the water supply tank 12 to the water supply tank 12.
An outlet valve 22 is provided in a discharge pipe 21 connected to the exhaust pipe 21.

Since the high-temperature heat storage device according to the present invention has the same structure as described above, the heat storage tank 1 is manufactured in advance in a factory, and a water supply means 10 with a backflow portion 15 is connected to the inlet side of the heat transfer tube 5 to transfer the heat. The steam discharge means 20 is connected to the outlet side of the heat pipe 5, the heat storage tank 1 is first installed and fixed at the use site, and then the water pipe 30 is connected to the water supply tank 12 of the water supply means 10.
Steam-using machinery and equipment 3 in the discharge pipe 21 of the steam discharge means 20
1 and the electric heater 4 and each of the valves 17, 18,
The power supply 22 is connected to a power supply, and the energization time to the electric heater 4 is set in accordance with the midnight power. In addition, the water supply means 10 and the steam discharge means 20 can be connected at the installation site of the heat storage tank 1.

Next, the method for effectively utilizing the heat energy by the back flow of the heat medium of the present invention will be described with reference to the high-temperature heat storage device of FIG.
The steam supply means 10 is provided on the outlet side of the heat transfer pipe 5, and the water supply means 10 is provided with a water supply tank 12 and a water supply pump 13, and a backflow portion 15 of the heat medium B in the heat transfer pipe 5. 13, the heat medium B in the heat transfer tube 5 can flow back from the backflow section 15 to the water supply tank 12 of the water supply means 10, and the inlet valve 17 of the backflow section 15 as shown in FIG.
Is opened and the midnight electric power is supplied to the electric heater 4 in a state where the outlet valve 22 of the steam discharge means 20 is closed, the heat storage material 6 is heated by the electric heater 4 and supplied to the heat transfer tube 5 by the heat storage material 6. The heated water W is heated and rises in temperature, eventually becomes high-temperature water, boils and turns into steam S, and the pressure in the heat transfer tube 5 is increased. As a result, the high-temperature water and steam S heated in the heat transfer tube 5 are heated.
The heat medium B of the back flow part 15 of the inlet valve 17 which is open,
That is, the water W flows back to the backflow portion 15 side of the water supply means 10, is discharged from the backflow portion 15 to the water supply tank 12, and heats the water W in the water supply tank 12.

When the steam S in the heat storage tank 1 heated by using the nighttime electric power is used, as shown in FIG.
5 is closed, and the outlet valve 2 of the steam discharging means 20 is closed.
2 is opened and the water supply pump 13 is operated, the water W in the water supply tank 12 is supplied to the heat transfer tube 5, whereby the heat medium B in the heat transfer tube 5 is pushed out to the steam discharge means 20 side,
The steam S is supplied from the discharge pipe 21 to the steam-using machinery 31 as steam S. When the supply of steam S is no longer required, the outlet valve 2
When the inlet valve 17 is opened almost simultaneously with the stop of the supply of the steam S by the closing of 2, the heat medium B remaining in the heat transfer tube 5 flows back to the water supply tank 12 through the inlet valve 17, so that the heat transfer tube 5 There is no pressure rise and the safety valve 18 does not operate. Moreover, the heat medium B that has flowed back into the water supply tank 12 from the inlet valve 17 heats the water W in the water supply tank 12, so that the heat energy of the heat medium B is effectively used and contributes to energy saving.

[0012]

[Experimental example] Specification of heat storage tank 1 Capacity of electric heater 4 = 27 KW, heat storage amount = 270 KW
h, 232Mcal Generated steam pressure = 0.5 MPa, Effective heat storage temperature = 150-
500 ° C. Heat output = 40 KW, temperature drop during standing = 0.4% / hour Heat storage material 6 = Magnesia 2700 Kg, nitrate 370 kg Heat transfer tube 5 is a steel tube, outer diameter = 22.2 mm, wall pressure = 1
mm, length = 40M, heat transfer area = 2.8 m2.

Table 1 shows changes in the temperature of the heat storage material, the temperature of the generated steam, and the amount of heat output when the steam S is taken out from the heat storage tank 1 in which heat has been stored by energizing the electric heater 4 for 10 hours.

[Table 1]

According to Table 1, the temperature of the heat storage material near the heat transfer tube 5 decreases at the start of the heat output, and the temperature of the heat storage material in the central portion starts to decrease 2 hours and 30 minutes after the heat output, and the vicinity of the outlet 5 hours later. The heat storage material temperature starts to decrease. The generated steam temperature was kept constant until 5 hours after the heat output, and then dropped sharply. The time when the steam temperature starts to decrease and the time when the temperature of the heat storage material near the outlet of the heat transfer tube 5 starts to coincide are the same. The heat output was substantially constant from about 7 hours 30 minutes after the start of heat output.

In the conventional heat storage tank (without an outlet valve), steam S is generated for 10 seconds to 3 minutes after the water supply pump is stopped. In the high-temperature heat storage device of the present invention, after the water supply pump 13 is stopped, the steam is transmitted. The heat medium B remaining in the heat pipe 5 flowed back through the inlet valve 17 for 0.5 to 3 seconds, and steam S was generated for 2 to 5 seconds.

[0016]

When the supply of steam S to the outside is stopped, the water supply pump 13 is stopped, and the inlet valve 17 and the outlet valve 22 are opened. Heat medium B remaining on the inlet side from the boiling point is supplied to water supply means 1 on the inlet side.
The heat medium B flows back to the water supply tank 12 from the inlet valve 17 of the backflow portion 15 and remains at the outlet side from the boiling point toward the steam discharge means 20 at the outlet side. It is discharged from 22.

When the heat medium B remaining in the heat transfer tube 5 is discharged in the state of water W, the volume becomes several tenths to one hundredth of that in the case of discharging in the state of steam S. Therefore, the time from when the water supply pump 13 is stopped to when the steam generation is completely stopped is shortened. When it is not necessary to return the heat medium B remaining in the heat transfer tube 5 to the water supply tank 12, the heat medium B can be discharged to the outside from the inlet valve 17. While the supply of steam S to the outside is not required, the inlet valve 17 is kept open, but the outlet valve 2
2 may be either open or closed.

When a steam-water mixer is used as the steam-using equipment 31 as shown in FIG. 4, the liquefied warm water generated by the steam-water mixer can be used for supplying water to the heat transfer tube 5. As the heat storage material 6, a magnesia clinker passing through a 10 mm square and hanging on a 7 mm square is 1700 kg, and a magnesia clinker passing through a 1 mm square is 1000 kg.
370 kg of a sodium nitrate / nitrite / potassium nitrate mixture is used. The high-temperature heat storage device according to the present invention and the method of effectively using the heat energy by the backflow of the heat medium are not limited to the above-described embodiment, and the steam S of the heat medium B heated in the heat storage tank 1 is used intermittently. If it does, it can be used for, for example, heating of a process, a heat source of an absorption refrigerator, washing, and the like.

[0019]

As described above, the high-temperature heat storage device of the present invention and the method of effectively utilizing the heat energy by the backflow of the heat medium have the following effects. When the supply of steam is stopped, the heat medium remaining in the heat transfer tube flows back to the water supply tank,
Thermal energy can be effectively used without waste. Moreover, even if the temperature in the heat storage tank decreases according to the heat output,
Since the temperature of the generated steam and the amount of heat output are stable, it is optimal as a high-temperature heat storage tank. Further, the supply of steam can be stopped within a short time after the supply of water is stopped. In particular, the use of nighttime electricity, which is set at a cheap price system, can provide the same level of economics as oil-fired boilers and water heaters.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a high-temperature heat storage device according to the present invention and a method of effectively utilizing heat energy by backflow of a heat medium.

FIG. 2 is a schematic view at the time of removing steam.

FIG. 3 is a schematic view when the steam discharging means is closed.

FIG. 4 is a schematic diagram showing an example of use of a high-temperature heat storage device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 heat storage tank 2 outer casing 3 inner casing 4 electric heater 5 heat transfer tube 6 heat storage material 7 heat insulating material 10 water supply means 11 water supply pipe, 12 water supply tank, 13 water supply pump 15 backflow section, 16 flow pipe, 17 inlet valve, 18
Safety valve 20 Steam discharge means 21 Discharge pipe, 22 Outlet valve W Water, B heat medium, S Steam 30 Water pipe, 31 Machinery and equipment using steam

Claims (3)

[Claims] 1. A water supply means (10) is provided on an inlet side of a heat transfer tube (5) constituting a heat storage tank (1), and a steam discharge means (20) is provided on an outlet side of the heat transfer tube (5). A high-temperature heat storage device characterized in that the water supply means (10) is provided with a backflow part (15) for the heat medium B in the heat transfer tube (5). 2. A water supply means (10) comprising: a water supply tank (1);
A water supply pump (13) is provided on a water supply pipe (11) connected between the heat transfer pipe (2) and the heat transfer pipe (5), and a backflow part (15) is provided for a flow pipe (15) from the heat transfer pipe (5) to the water supply tank (12). 2. An exhaust valve according to claim 1, further comprising an inlet valve provided at said outlet valve, and an outlet valve provided at said outlet pipe connected to said heat transfer pipe. High temperature heat storage device. 3. A water supply means (10) is provided on the inlet side of the heat transfer tube (5) of the heat storage tank 1, and a steam discharge means (20) is provided on the outlet side of the heat transfer tube (5). Is provided with a water supply tank (12), a water supply pump (13), and a backflow portion (15) of the heat medium B in the heat transfer tube (5). When the water supply pump (13) stops, the heat transfer tube (5) Wherein the heat medium B can flow back from the backflow portion (15) to the water supply tank (12).