JP2003279161A - Heat accumulating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat accumulating device capable of relaxing thermal shock acting on a heat transfer pipe and preventing vibration and noise of a sealed tank and a pipe connected to the sealed tank in start of heat output operation. <P>SOLUTION: In start of heat output operation, quantity of water supplied to the heat transfer pipe 5 provided in a heat accumulating tank 2 per a unit time is kept smaller than quantity of water supplied during normal operation. A solenoid valve 12 is opened in the concrete. Part of water flowing in the heat accumulating tank 2 flows into a return pipe passage 11 from a water supply pipe passage 7, quantity of water supplied to the heat accumulating tank 2 per a unit time is kept smaller than quantity of water supplied during normal operation in which the solenoid valve 12 is closed. Accordingly, quantity of superheated steam generated in the heat transfer pipe 5 gets smaller than that during normal operation, pressure rise in the heat transfer pipe 5 is relieved. Also, temperature variation of the heat transfer pipe 5 gets smaller. <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 heat storage device that stores heat in a substance having a large specific heat and uses the sensible heat later.

[0002]

2. Description of the Related Art Conventionally, the following types of heat storage devices have been known. That is, the heat storage material filled in the case is heated by a heater, and in this state, water is supplied by driving a pump from one of the heat transfer tubes embedded in the heat storage material,
Take out as superheated steam from the other. The superheated steam is introduced into a closed tank in which a predetermined amount of water is stored and mixed with the water in the closed tank to generate saturated steam. This saturated steam is supplied to the load side.

[0003]

However, the heat storage device has the following problems. That is, the discharge amount of the pump (the amount of water supplied to the heat storage tank) is constant, and when the constant amount of water is supplied into the heat storage tank from the start of the heat output operation, the water becomes steam at once and the heat transfer tube The pressure rises sharply. As a result, the heat transfer tube is burdened. Also,
When a large amount of water is supplied into the heat transfer tube heated by the heat of the heat storage material, the temperature of the heat transfer tube changes abruptly. That is,
The heat transfer tube is burdened by the thermal shock.

Furthermore, at the start of the heat output operation, the water temperature in the closed tank has dropped to about room temperature (especially cold in winter). Therefore, when a certain amount of water is supplied into the heat storage tank and a large amount of superheated steam flows into the closed tank,
The water in the closed tank evaporates rapidly. As a result, vibration and noise may occur in the closed tank, the pipes connected to the closed tank, and the like.

The present invention has been made to solve the above problems, and its purpose is to alleviate a thermal shock acting on a heat transfer tube and to connect to a closed tank and a closed tank at the start of heat output operation. It is an object of the present invention to provide a heat storage device capable of preventing the vibration and noise of the existing piping.

[0006]

The invention according to claim 1 supplies superheated steam by supplying a heat medium from one end of a heat transfer tube in a heat storage tank so that a supply amount per unit time becomes a predetermined supply amount. The superheated steam is introduced into the external closed tank from the other end of the heat transfer tube, and the heat medium in the closed tank is heated and saturated by heat exchange with the heat medium previously stored in the closed tank. The gist of the heat storage device configured to generate steam is that the supply amount of the heat medium to the heat storage tank per unit time is made smaller than the predetermined supply amount at the start of the heat output operation.

According to a second aspect of the present invention, in the heat storage device according to the first aspect, a pressure sensor for detecting the pressure in the closed tank is provided, and the pressure in the closed tank detected by the pressure sensor has a predetermined value. When the temperature reaches, the amount of the heat medium supplied to the heat storage tank per unit time is returned to the predetermined amount.

According to a third aspect of the present invention, in the heat storage device according to the first aspect, the saturated vapor temperature sensor for detecting the temperature of the saturated vapor in the closed tank, and the temperature of the heat medium stored in the closed tank are detected. A heat medium temperature sensor for detecting and a surface temperature sensor for detecting the temperature of the surface of the closed tank are provided, and the temperature of the saturated vapor detected by any one of the temperature sensors, The gist is that when the temperature or the temperature of the surface of the closed tank reaches a predetermined value, the supply amount of the heat medium to the heat storage tank per unit time is returned to the predetermined supply amount.

According to a fourth aspect of the present invention, in the heat storage device according to the first aspect, there is provided a time measuring means for measuring an elapsed time from the start of the heat output operation, and the time measured by the time measuring means. The gist is that when the predetermined time is reached, the supply amount of the heat medium to the heat storage tank per unit time is returned to the predetermined supply amount.

According to a fifth aspect of the present invention, in the heat storage device according to any one of the first to fourth aspects, the heat medium is supplied to the heat storage tank per unit time at the start of the heat output operation. A configuration in which the amount is less than the predetermined supply amount is a branch pipe connected so as to branch in the middle of the heat medium supply pipe to the heat storage tank, and a solenoid valve provided on the branch pipe, When the amount of heat medium supplied to the heat storage tank per unit time is less than the predetermined amount of supply, the control means opens the electromagnetic valve. When the valve is opened and the supply amount of the heat medium to the heat storage tank per unit time is set to the predetermined supply amount, the control means closes the electromagnetic valve.

According to a sixth aspect of the present invention, in the heat storage device according to the fifth aspect, a heat medium tank in which a heat medium to be supplied to the heat storage tank is previously stored is provided, and the branch pipe is provided at the start of the heat output operation. The gist is that the heat medium flowing into the passage is returned to the heat medium tank.

(Operation) According to the invention described in claim 1,
At the start of the heat output operation, the supply amount of the heat medium to the heat storage tank (strictly speaking, the heat transfer tube arranged in the heat storage tank) per unit time becomes smaller than the predetermined supply amount. For this reason,
The amount of superheated steam generated in the heat transfer tube is reduced, and the pressure increase in the heat transfer tube is moderate. Further, the temperature change of the heat transfer tube also becomes small.

According to the invention of claim 2, claim 1
In addition to the operation of the heat storage device according to, when the pressure in the closed tank detected by the pressure sensor reaches a predetermined value, the supply amount of the heat medium to the heat storage tank per unit time is the predetermined supply amount. Returned to.

According to the invention of claim 3, claim 1
In addition to the operation of the heat storage device described in [1], when the temperature of the saturated steam detected by any one of the temperature sensors, the temperature of the heat medium, or the temperature of the surface of the closed tank reaches a predetermined value, the heat storage tank The supply amount of the heat medium per unit time is returned to the predetermined supply amount.

According to the invention of claim 4, claim 1
In addition to the operation of the heat storage device described in, when the elapsed time from the start of the heat output operation measured by the timing means reaches a predetermined time, the supply amount of the heat medium to the heat storage tank per unit time is , The predetermined supply amount is restored.

According to the invention of claim 5, claim 1
In addition to the operation of the heat storage device according to any one of claims 4 to 4, when the supply amount of the heat medium to the heat storage tank per unit time is set to be smaller than the predetermined supply amount, the solenoid valve is used. The valve is opened. Then, a part of the heat medium to the heat storage tank flows into the branch conduit from the heat medium supply path. Therefore, the amount of the heat medium supplied to the heat storage tank per unit time is smaller than that when the electromagnetic valve is closed. When the supply amount of the heat medium per unit time to the heat storage tank is set to the predetermined supply amount, the solenoid valve is closed. Then, the heat medium is entirely supplied to the heat storage tank without flowing into the branch pipeline.

According to the invention of claim 6, claim 5
In addition to the operation of the heat storage device described in (1), the heat medium that has flowed into the branch pipe line at the start of the heat output operation is returned to the heat medium tank. Therefore, the heat medium that has flowed into the branch pipe is not wastefully discarded.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is embodied in a heat storage device will be described below with reference to FIG. As shown in FIG. 1, the heat storage device 1 includes a heat storage tank 2. The case 3 of the heat storage tank 2 is filled with a heat storage material 4 containing magnesia and nitrate as main components (only part of which is shown in FIG. 1). Inside the heat storage material 4, a heat transfer tube 5 in which water as a heat medium flows and a heater 6 for heating the heat storage material 4 are arranged. Both ends of the heat transfer tube 5 and the heater 6 penetrate the upper wall of the case 3 and are led out to the outside.

One end of the heat transfer pipe 5 is connected via a water supply pipe 7 to a water outlet of a water tank 8 in which a predetermined amount of water is stored in advance. A pump 9 is provided on the water supply pipe 7, and a check valve 10 is provided on the discharge side thereof. The discharge amount (L / min) of the pump 9 is constant. On the water supply line 7, the return line 1 is provided between the pump 9 and the check valve 10.
One end of the water tank 1 is connected, and the other end is also introduced from the upper opening of the water tank 8 into the inside.

An electromagnetic valve 12 is provided on the return conduit 11, and the return conduit 11 is opened or closed by opening and closing the electromagnetic valve 12. The opening degree of the solenoid valve 12 is set such that when the solenoid valve 12 is opened, half of the water supplied to the heat storage tank 2 flows into the branch pipe passage from the water supply pipe passage 7.

On the other hand, the other end of the heat transfer tube 5 is connected to the steam introduction line 13
Is introduced into the inside through the upper wall of the closed tank 14 through. A predetermined amount of water (pure water) is previously stored in the closed tank 14. Further, the closed tank 14 (specifically, the wall facing the retention part of the saturated steam) is connected to a steam supply pipe line 15 and provided with a pressure sensor 16 for detecting the pressure in the closed tank 14. Has been.

As shown in FIG. 1, the heat storage device 1 includes a control device 17 including a CPU and the like.
A pump 9, a solenoid valve 12 and a pressure sensor 16 are connected to each other via an input / output interface (not shown). The control device 17 performs drive stop control of the pump 9 and open / close control of the solenoid valve 12 based on the pressure in the closed tank 14 detected by the pressure sensor 16.

The water supply conduit 7 constitutes a heat medium supply conduit. The water tank 8 constitutes a heat medium tank. Return pipeline 1
1 constitutes a branch line. The control device 17 constitutes a control means.

(Operation of Embodiment) Next, the operation of the heat storage device configured as described above will be described. The heat output operation of the heat storage device 1 is started in a state where the heat storage material 4 is heated to about 500 ° C., for example, by heating the heater with electric power at night.
That is, at the start of the heat output operation, the control device 17 drives the pump 9 with the solenoid valve 12 open. Then, the water in the water tank 8 passes through the water supply pipe 7 and the heat transfer pipe 5 of the heat storage tank 2
I try to flow in.

However, since the solenoid valve 12 is opened, half of the water flowing through the water supply conduit 7 flows into the return conduit 11 and is returned to the water tank 8. Therefore, the other half is supplied into the heat transfer tube 5. That is, when the solenoid valve 12 is opened, the amount of water supplied to the heat storage tank 2 per unit time (water supply amount) is half (1/2) of that when the solenoid valve 12 is closed. Become. This is half the discharge amount of the pump 9.

When the water supplied into the heat storage tank 2 passes through the heat transfer tube 5, the heat of the heat storage material 4 is heated by being transferred through the tube wall of the heat transfer tube 5 and becomes superheated steam. At this time, since the amount of water supplied to the heat storage tank 2 per unit time is half of the normal amount (the solenoid valve 12 is closed), the amount of superheated steam generated in the heat transfer tube 5 is also halved. Therefore, the pressure increase in the heat transfer tube 5 at the start of the heat output operation is reduced. Further, the temperature change of the heat transfer tube 5 is smaller than that in the normal operation, and the thermal shock acting on the heat transfer tube 5 is alleviated.

The superheated steam generated in the heat transfer tube 5 is introduced into the water in the closed tank 14 through the steam introduction pipe line 13 and heat-exchanged with the water to generate saturated steam. At this time, even if the water temperature in the closed tank 14 is lowered to about room temperature (for example, 15 ° C.), the closed tank 14
The amount of superheated steam supplied to the inside is half the normal amount. For this reason, the degree of evaporation of water in the closed tank 14 becomes slower than in normal operation. Therefore, vibration and noise of the closed tank 14 and the pipes such as the steam supply pipeline 15 connected to the closed tank 14 are suppressed.

The pressure in the closed tank 14 rises with the generation of saturated steam, and the pressure (saturated steam pressure) in the closed tank 14 measured by the pressure sensor 16 is a predetermined value (for example, 0.1 kgf / cm ² ). The control device 17 causes the solenoid valve 12 to close. Then, all of the water discharged from the pump 9 is supplied to the heat storage tank 2 without flowing into the return conduit 11. That is, the amount of water supplied to the heat storage tank 2 per unit time is the same amount as the discharge amount of the pump 9 per unit time.

The saturated steam generated in the closed tank 14 is taken out to the outside via the steam supply pipe 15 at a predetermined steam supply pressure. In the present embodiment, the predetermined steam supply pressure, that is, the supply pressure of saturated steam to the load side is, for example, 5.0 kgf / cm ^2, and the pressure in the closed tank 14 is increased to this pressure to increase the load side. Is supplied to.

(Effects of Embodiment) Therefore, according to this embodiment, the following effects can be obtained. (1) At the start of the heat output operation, the amount of water supplied to the heat transfer tubes 5 arranged in the heat storage tank 2 per unit time is set to be smaller than the amount supplied during normal operation. Specifically, the solenoid valve 12 is opened. Then, a part of the water to the heat storage tank 2 flows from the water supply pipe 7 to the return pipe 11, and the amount of water supplied to the heat storage tank 2 per unit time is the solenoid valve 12 closed during normal operation. Less than. Therefore, the heat transfer tube 5
The amount of superheated steam generated inside is smaller than that during normal operation, and the pressure increase in the heat transfer tube 5 is moderate. Further, the temperature change of the heat transfer tube 5 becomes small. Therefore,
The thermal shock acting on the heat transfer tube 5 is alleviated. Further, vibration and noise of the closed tank 14 are prevented.

(2) At the start of the heat output operation, the pressure in the closed tank 14 detected by the pressure sensor 16 is a predetermined value (0.
When it reached 1 kgf / cm ² ), the amount of water supplied to the heat storage tank 2 per unit time was returned to the amount supplied during normal operation. Specifically, the solenoid valve 12 is closed. Therefore, as compared with the case where the amount of water supplied at the start of the heat output operation is maintained, the time required for the pressure in the closed tank 14 to reach the steam supply pressure becomes shorter. Therefore, the preparation for starting the heat output operation of the heat storage device 1 can be quickly performed.
In addition, when the pressure in the closed tank 14 reaches the predetermined value, the pressure in the closed tank 14 is reduced to such an extent that vibration and noise do not occur even if a large amount of superheated steam is supplied into the closed tank 14 during normal operation. The water is heated.

(3) When the solenoid valve 12 is opened, the solenoid valve 12 is opened so that half of the water supplied to the heat storage tank 2 flows into the return pipe 11 from the water supply pipe 7. I set the degree. Therefore, only by closing the solenoid valve 12, the amount of water supplied to the heat storage tank 2 per unit time can be halved (1/2) of the amount of water supplied during normal operation. Further, when the solenoid valve 12 is opened, the heat storage tank 2
Unlike the case where the opening of the solenoid valve 12 is set so that, for example, one-third of the water supplied to the return pipe 11 flows from the water supply pipe 7, the opening of the solenoid valve 12 can be adjusted. It will be easy. Furthermore, since the return pipe line 11 is connected to the water supply pipe line 7 and the solenoid valve 12 is provided on the return pipe line 11, the structure of the heat storage device 1 does not become complicated.

(4) Return pipe 1 at the start of heat output operation
The water flowing into No. 1 was returned to the water tank 8. Therefore, the water flowing into the return conduit 11 is not wasted and can be effectively used.

(Other Example) The above embodiment may be modified as follows. In the present embodiment, at the start of heat output operation, when the pressure in the closed tank 14 detected by the pressure sensor 16 reaches a predetermined value, the amount of water supplied to the heat storage tank 2 per unit time is
Although the supply amount in the normal operation is restored, it may be set as follows. That is, as shown by the chain double-dashed line in FIG. 1, the closed tank 14 may be provided with a saturated steam temperature sensor 21 for detecting the temperature of the saturated steam in the closed tank 14. Then, at the start of the heat output operation, when the temperature of the saturated steam detected by the saturated steam temperature sensor 21 reaches a predetermined temperature, the supply amount of water to the heat storage tank 2 per unit time is set to the supply amount in the normal operation. return. Even in this case, the time required for the pressure in the closed tank 14 to reach the steam supply pressure becomes shorter than in the case where the amount of water supplied at the start of the heat output operation is maintained, and the heat storage device 1 The preparation for starting the heat output operation can be quickly performed. Also, the closed tank 14
Also, vibration and noise of the piping such as the steam supply pipeline 15 are suppressed.

Similarly, as indicated by the chain double-dashed line in FIG.
The closed tank 14 may be provided with a heat medium temperature sensor 22 that detects the temperature of the water stored in the closed tank 14. Then, at the start of the heat output operation, when the temperature of the water detected by the heat medium temperature sensor 22 reaches a predetermined temperature, the amount of water supplied to the heat storage tank 2 per unit time is returned to the amount supplied during normal operation. . Even in this case, the time required for the pressure in the closed tank 14 to reach the steam supply pressure becomes shorter than in the case where the amount of water supplied at the start of the heat output operation is maintained, and the heat storage device 1 The preparation for starting the heat output operation can be quickly performed. Also, the closed tank 14
Also, vibration and noise of the piping such as the steam supply pipeline 15 are suppressed.

Similarly, as shown by the chain double-dashed line in FIG.
The closed tank 14 is provided with a surface temperature sensor 23 for detecting the temperature of the surface of the closed tank 14, and at the start of the heat output operation, the closed tank 1 detected by the surface temperature sensor 23.
When the surface temperature of No. 4 reaches a predetermined temperature, the amount of water supplied to the heat storage tank 2 per unit time is returned to the amount supplied during normal operation. Even in this case, the time required for the pressure in the closed tank 14 to reach the steam supply pressure becomes shorter than in the case where the amount of water supplied at the start of the heat output operation is maintained, and the heat storage device 1 The preparation for starting the heat output operation can be quickly performed. Further, the closed tank 14 and the steam supply line 15
Vibration and noise of pipes are suppressed.

Similarly, after a lapse of a predetermined time (for example, 3 minutes) from the start of the heat output operation, the supply amount of water to the heat storage tank 2 per unit time is returned to the supply amount in the normal operation. You may That is, as shown by the chain double-dashed line in FIG. The timer 24 is started at the same time when the heat output operation is started, and outputs a count-up signal when a predetermined time has elapsed. Based on this, the control device 17 closes the solenoid valve 12. The predetermined time is obtained in advance by experimental data from a device model and well-known theoretical calculations, etc., and the sealed tank 14 is sealed to such an extent that vibration and noise do not occur even when a considerable amount of superheated steam is supplied during normal operation. This is the time until the water in the tank 14 is heated. Even in this case, the time required for the pressure in the closed tank 14 to reach the steam supply pressure becomes shorter than in the case where the amount of water supplied at the start of the heat output operation is maintained, and the heat storage device 1 The preparation for starting the heat output operation can be quickly performed. Also,
Vibration and noise in the closed tank 14, the steam supply pipeline 15, and the like are suppressed.

In the present embodiment, the water flowing into the return conduit 11 is returned to the water tank 8, but it may be discharged. Even in this case, (1) of the present embodiment
The same effect as that of (3) can be obtained.

In the present embodiment, when the solenoid valve 12 is opened, half (1/2) of the water supplied to the heat storage tank 2 flows into the return pipe 11 from the water supply pipe 7. Although the opening degree of the solenoid valve 12 is set in the above, it may be set arbitrarily. That is, the opening degree of the solenoid valve 12 is set so that the amount of water supplied to the heat storage tank 2 per unit time is smaller than the amount of discharge of the pump 9 per unit time. For example, one-third of the water supplied to the heat storage tank 2,
The opening degree of the solenoid valve 12 is set so that one-fourth, one-fifth, and three-fourths flow into the return conduit 11 from the water supply conduit 7. Even in this case, the same effects as (1) to (4) of this embodiment can be obtained.

[0040]

According to the present invention, when the heat medium supply amount per unit time to the heat transfer tube of the heat storage tank at the start of the heat output operation is made smaller than the supply amount at the time of the normal operation, the heat transfer tube is provided. It is possible to reduce the thermal shock that acts and to prevent vibration and noise of the closed tank and the pipes connected to the closed tank.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a heat storage device in the present embodiment.

[Explanation of Codes] 1 ... Heat storage device, 2 ... Heat storage tank, 5 ... Heat transfer tube, 7 ... Water supply pipe line constituting heat medium supply pipe line, 8 ... Water tank constituting heat medium tank, 11 ... Branch pipe line Return pipelines that make up 12
... Solenoid valve, 14 ... Closed tank, 16 ... Pressure sensor, 17
... Control devices 17 and 21 that constitute control means ... Saturated steam temperature sensor, 22 ... Heat medium temperature sensor, 23 ... Surface temperature sensor, 24 ... Timer that constitutes time measuring means.

Claims (6)

[Claims] 1. A heat medium is supplied from one end of a heat transfer tube in a heat storage tank to form superheated steam so that the supply amount per unit time becomes a predetermined supply amount, and this superheated steam is externally supplied from the other end of the heat transfer tube. In a heat storage device that guides the heat medium in the closed tank to heat the heat medium stored in the closed tank in advance and heats the heat medium in the closed tank to generate saturated steam, A heat storage device in which a supply amount of a heat medium to the heat storage tank per unit time is set to be smaller than the predetermined supply amount at the start of operation. 2. A pressure sensor for detecting the pressure in the closed tank is provided, and when the pressure in the closed tank detected by the pressure sensor reaches a predetermined value, the heat medium is supplied to the heat storage tank per unit time. The heat storage device according to claim 1, wherein the amount is returned to the predetermined supply amount. 3. A saturated steam temperature sensor for detecting the temperature of saturated steam in a closed tank, a heat medium temperature sensor for detecting the temperature of a heat medium stored in the closed tank, and a surface temperature of the closed tank. When any one of the surface temperature sensors is provided and the temperature of the saturated steam, the temperature of the heat medium or the surface temperature of the closed tank detected by any one of the temperature sensors reaches a predetermined value, heat storage The heat storage device according to claim 1, wherein the supply amount of the heat medium per unit time to the tank is returned to the predetermined supply amount. 4. A heat medium per unit time to a heat storage tank, comprising time measuring means for measuring an elapsed time from the start of the heat output operation, and when the time measured by the time measuring means reaches a predetermined time. The heat storage device according to claim 1, wherein the supply amount of is returned to the predetermined supply amount. 5. A configuration in which the supply amount of the heat medium to the heat storage tank per unit time at the start of the heat output operation is smaller than the predetermined supply amount is branched in the middle of the heat medium supply pipe line to the heat storage tank. And a solenoid valve provided on the branch pipe, and a control unit for controlling the opening and closing of the solenoid valve, and the supply of the heat medium to the heat storage tank per unit time. When the amount is less than the predetermined supply amount, the control means opens the solenoid valve, and when the supply amount of the heat medium to the heat storage tank per unit time is the predetermined supply amount, The heat storage device according to any one of claims 1 to 4, wherein the control means closes an electromagnetic valve. 6. A heat medium tank in which a heat medium to be supplied to the heat storage tank is stored in advance, and the heat medium flowing into the branch pipe is returned to the heat medium tank at the start of the heat output operation. Item 5. The heat storage device according to item 5.