JPWO2016121117A1 - Thermal storage type exhaust heat recovery device, combustion device using the same, and cogeneration system - Google Patents

Abstract

The present invention uses a heat medium whose volume expands as the temperature rises without using power from a pump or the like, and naturally circulates the heat medium only by exhaust heat, thereby eliminating exhaust with large heat fluctuation. An object of the present invention is to provide a heat storage type exhaust heat recovery device that efficiently stores and recovers heat, a combustion device using the same, and a cogeneration system, and stores exhaust heat transmitted from the high-temperature wall of the combustion device. This is a heat storage type exhaust heat recovery device that recovers, and the heat storage type exhaust heat recovery device comprises a narrow wall surface for storing or circulating a heat storage medium provided outside the high temperature wall surface. A heat transfer pipe for circulating the medium is provided. The heat storage medium is stored or circulated in the narrow wall surface, and the working medium is circulated in the heat transfer pipe so that the working medium is transmitted from the hot wall surface. Ru Instead of recovering heat directly, a regenerative heat recovery apparatus characterized by indirectly recovered via the heat storage medium.

Description

The present invention relates to a heat storage type exhaust heat recovery device that recovers exhaust heat exhausted from a small-scale combustion device and a combustion device using the same, and also stores the recovered heat as sensible heat and stores the heat. The present invention relates to a cogeneration system that generates heat by driving a turbine using heat.

Technologies that make effective use of waste heat (or waste heat) from chemical plants and combustion equipment, in addition to reducing fossil fuel consumption, can contribute to the construction of a low-carbon recycling social system with a low environmental impact. It will be more and more important in the future.

For example, waste heat from waste incineration equipment is mainly used for preheating the working medium via a heat exchanger, recovered and supplied as hot water, or driven by turbines with superheated steam to generate electricity and heat. It can be broadly divided into cogeneration systems that perform simultaneous supply (combined with thermoelectrics).
In any form, the exhaust heat recovery efficiency is improved together with the performance of the heat exchanger, and the system performance has been improved by incorporating various sensors and control technologies.

In particular, the form of cogeneration systems that use waste heat to supply electricity and heat simultaneously has become widespread in large-scale facilities that can stably secure high-temperature waste heat while taking into account economic benefits. Yes. On the other hand, in small-scale combustors and intermittent combustion furnaces with an incineration amount of 100 tons or less per day, there are many cases where exhaust heat necessary for power generation cannot be constantly secured, so superheated steam for driving the turbine Therefore, it is difficult to establish a cogeneration system with exhaust heat only from a small combustion device.

In recent years, for small-scale combustion devices and intermittent combustion furnaces, it has been realized that dioxins will not be discharged by combining control and monitoring technologies due to higher combustion temperatures and rapid cooling technology for flue gas. ing. As a result, the demand for equipment has increased, and the trend of technological development for effective use of exhaust heat, as well as large-scale equipment, has attracted attention.

For example, Patent Document 1 discloses a method of maintaining a constant power generation output of a steam turbine by mixing felled wood and biological resources into an incinerated product and ensuring a certain amount of combustion heat.

Patent Document 2 discloses a power generation method that secures stable superheated steam by reheating a working medium preheated by heat exchange in an incinerator using an auxiliary boiler.

Furthermore, in recent years, a binary power generation system that recovers exhaust heat using a low-boiling working medium and drives a turbine with relatively low-temperature superheated steam as a form of using exhaust heat at a temperature of about 100 ° C. such as hot spring heat. Although it has been put into practical use, it is important that the heat of a certain temperature can be secured sufficiently and constantly in the system.

JP2013-066451A Japanese Patent Laid-Open No. 07-012303

In order to construct a cogeneration system using the exhaust heat of a small-scale combustion device, it is necessary to solve the following problems.
(1) When the device is downsized, it is difficult to secure a heat transfer area for recovering exhaust heat (the effective heat transfer area is small) and the fluctuation of combustion heat is large. Technical means are required to ensure it on a regular basis.
(2) Since the surface area per unit volume increases as the device becomes smaller, the amount of heat released to the outside air, that is, the heat loss, becomes larger than the large device, and the heat recovered using the heat medium or the working medium is Heat is released to the outside air, and the heat recovery rate is greatly reduced.
In other words, it is necessary to improve the characteristic of “easy to heat and easy to squeeze” unique to a small combustion apparatus.
(3) In the conventional exhaust heat recovery device, when exhaust heat recovery is performed using water or a low boiling point or low temperature heat medium, the thermal conditions (temperature, pressure, heat transfer coefficient) of the heat medium are combusted. Since it directly affects the chamber and the hot wall surface, the combustion temperature is lowered and the wall surface is deformed. In some cases, the combustion chamber wall surface may burn out.
(4) When a conventional exhaust heat recovery device is applied to a cogeneration system, the thermal fluctuation (temperature, calorific value) of the combustion chamber directly affects the temperature and pressure of the working medium, and stable superheated steam, that is, stable It is difficult to obtain power generation output.

Therefore, in view of the above problems, the present invention stores a heat storage type exhaust heat recovery device capable of storing and supplying a stable heat at a constant temperature by storing exhaust heat of a small combustion furnace or the like having a large thermal fluctuation, and a combustion using the same An apparatus and a cogeneration system are provided.

The regenerative exhaust heat recovery device according to the present invention is
A heat storage type exhaust heat recovery device for storing and recovering exhaust heat transmitted from a high temperature wall surface of a combustion device,
Thermal storage waste heat recovery equipment
It consists of a narrow wall surface for storing or circulating a heat storage medium provided outside the high temperature wall surface,
A heat transfer tube for circulating the working medium is installed in the narrow wall surface,
By storing or circulating the heat storage medium in the narrow wall surface, and circulating the working medium in the heat transfer tube,
The working medium does not directly recover the exhaust heat transmitted from the high-temperature wall surface, but indirectly recovers it through the heat storage medium.

A conventional exhaust heat recovery device supplies a working medium or heat medium (water at around 20 ° C.) to a hot wall surface, and collects the exhaust heat transmitted from the wall surface in a state where the wall surface and the working medium are in direct contact with each other. It is a form to do. When this form is applied to a small-scale combustion apparatus, there are the following problems.
(1) When a low-temperature working medium or heat medium is supplied into the apparatus, the wall surface temperature of the combustion apparatus may be lowered, and further the combustion state (temperature, calorific value) inside the combustion chamber may be affected. For example, in a waste incinerator, the combustion temperature is lowered, and a harmful substance is generated.
(2) A large temperature difference (temperature gradient) occurs between the inner side (combustion chamber side, high temperature) and the outer side (surface where the heat medium is in contact) of the combustion device, and the wall surface of the combustion device is deformed by thermal stress. Risk of damage.
(3) When the heat medium dries out and becomes superheated steam, a rapid temperature rise of the wall surface and a pressure increase in the system occur, and the wall surface is burned out and the wall surface is deformed by pressurization.
(4) When the combustion furnace side wall surface and the outside air side wall surface are in contact with each other via the working medium, the heat loss (heat radiation to the outside) of the working medium increases, the heat recovery rate decreases, and steam is generated. Becomes unstable.

Therefore, the heat storage type exhaust heat recovery apparatus according to the present invention is a liquid having a saturation temperature higher than the saturation temperature of water (100 ° C., 1 atm), that is, a heat storage medium having a high boiling point and a high heat capacity, and water or a low boiling point operation. By using two types of heat medium, medium, and piping a heat transfer pipe in a narrow wall surface that stores or circulates the heat storage medium provided outside the high temperature wall, and circulating the working medium in the heat transfer pipe The exhausted heat can be recovered safely and efficiently without the working medium directly touching the side wall surface of the combustion device and the side wall surface of the outside air.

In this invention, a wall surface means wall surfaces, such as a combustion chamber (combustion furnace) of a combustion apparatus and a chimney part heated to high temperature by combustion.
Moreover, the wall surface narrow space is a space sandwiched between wall surfaces provided on the outside of the wall surface of the combustion chamber (combustion furnace) or chimney of the combustion apparatus, and the space can be provided only by a part of the wall surface, It can also be provided in the entire range, that is, all the walls of the combustion chamber (combustion furnace) and chimney. It is desirable that the outside air side wall surface (outer wall) in the narrow wall surface has heat insulation so as not to be affected by the outside air environment.

In the present invention, the heat transfer tube is piped in a narrow wall surface and circulates the working medium inside the tube. The heat transfer tube can be piped in the vertical direction in the narrow space on the wall surface, piped along the wall surface as a spirally formed tube, or piped in the spiral direction along the periphery of the wall surface.
A power source such as a pump for circulating the heat storage medium or the working medium outside the apparatus can be provided separately.

The heat storage medium in the present invention has a boiling point of about 300 to 400 ° C. at 1 atm, and a liquid whose volume increases with increasing temperature, that is, a liquid having a large temperature expansion coefficient (for example, a volume ratio of 1 at a temperature of 25 to 300 ° C. ~ 1.5 or less). In addition, when the wall space is filled with a heat storage medium in which metal fibers or metal particles are embedded, heat transfer from the high temperature wall surface to the heat storage medium is promoted, and the temperature distribution of the heat storage medium is made uniform, so that heat storage and temperature control are achieved. Improves.

The working medium in the present invention can use water or a low-boiling point (boiling point of 100 ° C. or lower) pentane or butane, or a fluorocarbon refrigerant. By using such a working medium, low-temperature exhaust heat recovery at a temperature of 100 ° C. or lower is possible, and the superheated steam necessary for driving the steam turbine can be secured more stably.

According to the present invention, even if low-temperature water or a low-boiling working medium is supplied into the apparatus, the temperature and heat generation amount of the wall surface of the combustion apparatus and the combustion chamber are not reduced, and the wall surface is deformed or burned out. Can be prevented.
In addition, since the low-boiling working medium does not come into direct contact with the high-temperature wall surface of the combustion device, it is avoided that the temperature difference (temperature gradient) between the inside and outside of the wall surface becomes extremely large, and is caused by thermal stress. It is possible to prevent deformation of the wall surface, burnout of the combustion furnace wall surface due to a decrease in heat transfer, and pressure deformation of the wall surface due to superheated steam.

Further, in cogeneration that uses the exhaust heat of the combustion device for power generation, it is necessary to always secure the thermal energy necessary for power generation.
Accordingly, by providing the small combustion device with a heat storage function according to the present invention, a stable supply of superheated steam, that is, a stable power generation output can be obtained even in a small combustion device having a large thermal fluctuation of exhaust heat.

The regenerative exhaust heat recovery device according to the present invention is
A heat storage type exhaust heat recovery device for storing and recovering exhaust heat transmitted from a high temperature wall surface of a combustion device,
Thermal storage waste heat recovery equipment
It consists of a narrow space on the outside of the hot wall,
The wall surface narrow space is partitioned into a high temperature wall surface space (inner wall side space) and an outer wall side space (outer wall side space) of the wall surface narrow space by a partition that opens above and below the space.
In the inner wall side space, a heat transfer tube for circulating the working medium is installed,
When the heat storage medium stored in the inner wall side space stores exhaust heat and becomes high temperature, the heat storage medium flows from the opening part above the partition wall to the outer wall side space and is cooled, and returns from the opening part below the partition wall to the inner wall side space. In this case, the exhaust heat is stored again to become a high temperature, and this is repeated so that it circulates in both spaces, and the heat transfer pipe that is piped to the inner wall side space where the heat storage medium controlled to a constant temperature circulates by this circulation In addition, by circulating the working medium,
The working medium does not directly recover the exhaust heat transmitted from the high-temperature wall surface, but indirectly recovers it through the heat storage medium.

The present invention divides a wall surface narrow space of the heat storage type exhaust heat recovery device into an inner wall side space and an outer wall side space by a partition wall, and the heat storage medium passes through both spaces above and below the wall surface narrow space. It is designed to circulate naturally between spaces.

When using the exhaust heat from a small-scale combustion device for power generation, it is necessary to supply superheated steam with a constant thermal condition (temperature, pressure, flow rate) to the turbine inlet to obtain a stable power output with a constant frequency. There is. For this reason, it is desirable that the temperature of the heat storage medium serving as the heat source of the working medium be kept constant or uniform.

Therefore, in the present invention, the narrow wall surface provided outside the high-temperature wall surface is partitioned by a partition wall having openings on both the upper and lower sides, and the high-temperature heat medium (inner wall side) and the low-temperature heat medium (outer wall side) It was set as the structure which can circulate through an opening part. As a result, the heat storage medium naturally circulates in a form that maintains a thermal balance (an aspect that compensates for the density difference) so that the temperature of the heat storage medium and the apparatus is constant or uniform.

The heat storage medium used in the present invention stores high-temperature exhaust heat from the wall surface as sensible heat in the inner wall side space, and the volume increases as the temperature rises and flows from the opening above the partition wall to the outer wall side space. The heat is radiated or cooled in the outer wall side space. And the cooled thermal storage medium becomes a downward flow by the specific volume decreasing (density increasing), and flows into the inner wall side space from the opening part under a partition.
As a result, the natural circulation continues in a form that maintains the thermal balance between the heating and cooling zones, and the temperature of the heat storage medium and the device is kept constant or uniform, and temperature control is possible only with the thermal driving force. It becomes.

The partition wall in the present invention has heat insulating properties, and divides the narrow wall surface into a high-temperature wall-side space (inner wall-side space, high temperature) and an outer-wall-side space (outer wall-side space, low-temperature) in the narrow wall surface. To do.
However, the wall surface narrow space is not completely separated from the outer wall side space and the inner wall side space, and the upper and lower spaces of the wall surface narrow space are left open. Through this open space (opening portion), the heat storage medium moves through each space and circulates. The outer wall of the narrow wall surface may be a heat insulating wall so as not to be affected by the outside air temperature, or may be a cooling wall for cooling the heat storage medium, and varies depending on the temperature condition of the heat storage medium.
Further, the partition wall that divides the wall surface narrow space into the inner wall side space and the outer wall side space preferably has heat insulating properties so that heat is not transmitted through the partition wall between the inner wall side space and the outer wall side space. .

Even in this configuration, even if low-temperature water or a low-boiling working medium is supplied into the apparatus, the working medium does not directly touch the high-temperature wall surface. There is no lowering, and there is no wall deformation or burning.
As described above, by embedding metal fibers or metal particles in the narrow wall surface space or the inner wall space where the heat storage medium is circulated, heat transfer from the high temperature wall surface to the heat storage medium is promoted, and the temperature of the heat storage medium is increased. The distribution is made uniform to improve heat storage and temperature controllability.

The regenerative exhaust heat recovery device according to the present invention is
A heat storage type exhaust heat recovery device for storing and recovering exhaust heat transmitted from a high temperature wall surface of a combustion device,
Thermal storage waste heat recovery equipment
It consists of a narrow space on the outside of the hot wall,
The wall surface narrow space is partitioned by a partition wall into a high temperature wall surface space (inner wall side space) and an outer wall side space (outer wall side space) of the wall surface narrow space,
In the inner wall side space, a heat transfer pipe for circulating the working medium is piped,
In order to transfer and circulate the heat storage medium in the inner wall side space to the outer wall side space, the outer wall side space connects the opening formed in the lower part of the partition through the outer wall side space to circulate. An annular heat radiating pipe is installed,
When the heat storage medium stored in the inner wall side space stores the exhaust heat and becomes high temperature, the heat storage medium is cooled while flowing through the heat radiating pipe piped in the outer wall side space from the opening formed above the partition wall. Then, it returns to the inner wall side space from the opening formed below the partition wall, accumulates the exhaust heat again and becomes high temperature, and this is repeated to circulate between both spaces, and this circulation makes the temperature constant (desired) By circulating the working medium in the heat transfer pipe piped in the inner wall side space so as to come into contact with the controlled heat storage medium,
The working medium does not directly recover the exhaust heat transmitted from the high-temperature wall surface, but indirectly recovers it through the heat storage medium and the heat transfer tube wall surface.

The present invention divides a narrow wall surface space of the heat storage type exhaust heat recovery apparatus into an inner wall side space and an outer wall side space by a partition wall, and connects openings formed above and below the partition wall with a heat radiating pipe to store heat. The medium is cooled while moving and descending in the heat radiating pipe piped in the outer wall side space, so that the heat storage medium naturally circulates in both spaces by a thermal driving force due to a temperature difference.

When using the exhaust heat of a small-scale combustion device for power generation, it is necessary to obtain a stable frequency power output by keeping the thermal conditions (temperature, pressure, flow rate) of the superheated steam supplied to the turbine inlet constant. There is. For this reason, it is desirable that the temperature of the heat storage medium serving as the heat source of the working medium be kept constant or uniform.

Therefore, in the present invention, the narrow wall surface provided outside the high-temperature wall surface is partitioned by a partition wall having openings on both the upper and lower sides, and the high-temperature heat medium (inner wall side) and the low-temperature heat medium (outer wall side) It was set as the structure which can circulate through an opening part. As a result, the heat storage medium naturally circulates in a form that maintains a thermal balance (an aspect that compensates for the density difference) so that the temperature of the heat storage medium and the apparatus is constant or uniform.
The heat storage medium collects the high-temperature exhaust heat from the wall surface in the inner wall side space, stores the heat, and as the temperature rises, the inside of the heat radiating pipe piped into the outer wall side space from the opening formed above the partition wall Radiated or cooled in the outer wall side space.
Then, the heat storage medium to be cooled has a specific volume that decreases (density increases) as the temperature decreases and flows downward, and flows from the opening formed below the partition wall to the inner wall side space. By repeating the above circulation process, the temperature of the heat storage medium is kept constant or uniform.
As a result, the exhaust heat transferred from the high-temperature wall surface is stored in the heat storage medium with a high boiling point and a high heat capacity, and the working medium recovers the sensible heat held by the heat storage medium. Even in the combustion apparatus, the working medium is not directly affected by the heat fluctuation (change in temperature and amount of heat) in the combustion chamber, and stable superheated steam can be generated and supplied.

The partition wall in the present invention has heat insulating properties, and divides the narrow wall surface into a high-temperature wall-side space (inner wall-side space, high temperature) and an outer-wall-side space (outer wall-side space, low-temperature) in the narrow wall surface. To do.
The partition wall in the present invention is provided with an opening above and below the partition wall. An annular heat radiating pipe is piped so as to connect the upper and lower openings. Therefore, the heat storage medium flows from the inner wall side space to the outer wall side space through the opening, and is cooled while passing through the heat radiating pipe.
Moreover, it is desirable that the partition wall that partitions the wall surface narrow space into the inner wall side space and the outer wall side space has a heat insulating property so that there is no heat transfer through the partition wall between the inner wall side space and the outer wall side space.

Water or refrigerant is used for cooling the heat radiating pipe. In the case of water, the heat obtained from the heat radiating pipe can be recovered and supplied as hot water to the outside of the apparatus.
In addition, when circulating the refrigerant, a cooling device such as a chiller is used, and cooling at a low temperature not exceeding room temperature or outside temperature is possible.

Fins or grooves can be formed on the surface of the heat radiating tube in order to enhance the effect of heat dissipation or cooling of the heat storage medium circulating in the heat radiating tube. The fins can be formed on the outer peripheral side of the heat radiating tube, and the grooves can be formed on the inner peripheral side of the heat radiating tube. That is, by providing fins and grooves on the inner and outer surfaces of the heat radiating tube, there is an effect of increasing the heat radiation amount of the heat storage medium circulating in the heat radiating tube.

The outer wall of the narrow wall surface has heat insulation so as not to be affected by the outside air temperature. It is desirable that the heat transfer to the outside air be reduced to reduce the heat loss of the heat storage medium and the cooling water (refrigerant).

As described above, in this configuration, even when low-temperature water or a low-boiling working medium is supplied into the apparatus, the working medium does not directly touch the high-temperature combustion furnace wall. In addition, the wall surface is not deformed or burned out.
In addition, it is possible to improve heat storage property and temperature controllability by embedding metal fibers or metal particles in the narrow wall surface space, the inner wall side space, or the outer wall side space in which the heat storage medium is circulated.

The heat radiating pipe in the present invention is a pipe piped in the outer wall side space in order to cool the heat storage medium in the inner wall side space in the outer wall side space. It is a pipe that connects the opening formed above the partition wall (inlet of the heat radiating pipe) to the opening formed below the partition wall (exit of the heat radiating pipe) through the outer wall side space. It is also possible to make a spiral tube that spirally connects the inside of a narrow wall surface.
In addition, heat transfer from the high temperature wall surface to the heat storage medium is promoted and the temperature distribution of the heat storage medium is made uniform by mixing metal fibers or metal particles in the narrow wall surface space or the inner wall side space through which the heat storage medium is circulated. This improves heat storage performance and temperature controllability.

The regenerative exhaust heat recovery device according to the present invention is
The heat storage medium circulating through the inner wall side space is
It is a heat medium composed of a liquid whose boiling point at normal pressure is higher than that of water and whose volume increases as the temperature rises (volume ratio at 25 to 300 ° C. is 1.5 times or less than 1 at normal temperature),
The heat storage medium (initial state) before storing the exhaust heat is stationary at a position where the liquid surface, that is, the gas-liquid interface is lower than the opening or opening part above the partition wall, but the temperature rises after storing the exhaust heat As the volume expands along with the liquid level rises toward the opening or opening part above the partition wall,
When the desired temperature is reached, the heat storage medium flows into the outer wall side space from the opening part above the partition wall or into the heat radiating pipe that is piped into the outer wall side space from the opening part formed above the partition wall. By circulating between the outer wall side space and the outer wall side space so that heat is radiated or cooled in the outer wall side space,
It is characterized in that the temperature of the heat storage medium that collects and stores the exhaust heat can be controlled.

The heat storage medium in the present invention has a higher boiling point at normal pressure than that of water (for example, the boiling point at normal pressure is about 350 ° C.), and has a property that the volume increases with an increase in temperature, that is, a temperature dependence of volume expansion coefficient is large. (For example, a volume ratio of 1 to 1.5 or less at a temperature of 25 to 300 ° C.).
In addition, the liquid level of the heat storage medium is lower than the opening or the opening part above the partition wall before storing the exhaust heat (initial state), and the volume increases as the temperature rises after storing the exhaust heat. When the liquid level rises and becomes higher than the opening or the opening portion above the partition wall, when the desired temperature is reached, the heat storage medium is transferred from the opening portion above the partition wall to the outer wall side space or the partition wall. By flowing into the heat radiating pipe piped in the outer wall side space from the opening formed in the upper part, circulating between the inner wall side space and the outer wall side space so that heat is radiated or cooled in the outer wall side space. The temperature of the heat storage medium from which the exhaust heat is recovered, that is, the heat storage temperature can be controlled.

When exhaust heat from a small-scale combustion device is used for power generation, superheated steam with a constant thermal condition (temperature, pressure, flow rate) is supplied to the turbine inlet to obtain a stable power output with a constant frequency. There is a need. For this reason, it is desirable that the temperature of the heat storage medium serving as the heat source of the working medium be kept constant or uniform.

Therefore, the present invention maintains a constant temperature by allowing the heat storage medium to circulate naturally between the inner wall side space and the outer wall side space and radiate or cool in the outer wall side space when the desired temperature is reached. In order to be able to do so, the boiling point at normal pressure is higher than that of water (for example, the boiling point at normal pressure is about 350 ° C.), and the volume ratio is 1 to 1.5 or less while the temperature rises to 25-300 ° C. The heat storage medium has the property of increasing up to.
Therefore, in consideration of this volume change (relationship between the temperature of the heat storage medium and the volume expansion coefficient), the filling amount of the heat storage medium that fills the wall surface narrow space is determined. That is, when the desired temperature is reached, the filling amount and the liquid level height in the initial state are determined so that the liquid level height of the heat storage medium reaches the opening above the partition wall, and the heat storage medium passes through the wall sandwiched space. The starting temperature for natural circulation is set.

The regenerative exhaust heat recovery device according to the present invention is
The heat storage medium circulating through the inner wall side space is
A heating medium composed of a liquid whose boiling point at normal pressure is higher than that of water and whose volume increases as the temperature rises (volume ratio at 25 to 300 ° C. is 1.5 times or less than 1 at normal temperature) is spiral. Is a mixed heat storage medium in which curled metal fibers and metal ribbons are mixed,
Before storing the exhaust heat, the liquid level of the heat storage medium that is stationary at a position lower than the opening or opening portion above the partition wall expands as the temperature rises after storing the exhaust heat. In the case where the liquid level rises and becomes higher than the opening or opening part above the partition wall,
When a certain temperature is reached, the heat storage medium flows into the outer wall side space from the opening part above the partition wall or into the heat radiating pipe piped into the outer wall side space from the opening part formed above the partition wall, and the inner wall side space. By circulating between the outer wall side space and the outer wall side space so that heat is radiated or cooled in the outer wall side space,
It is characterized in that the temperature of the heat storage medium that collects and stores the exhaust heat can be controlled.

The mixed heat storage medium is a liquid heat storage medium mixed with spirally curled metal fibers or metal ribbons. The metal fiber or the metal ribbon of the mixed heat storage medium is a thin line (equivalent diameter De = 0.02 to 0.3 mm) having a circular shape, an ellipse, or a corner in cross section, and a series of continuous bodies curled spirally or It consists of an aggregate of fine lines that have been cut. Here, the equivalent diameter De is defined as De = A / S as a value obtained by dividing the cross-sectional area A [m ² ] of the thin wire by the cross-sectional circumferential length S [m].

Moreover, the length of the metal fiber or metal ribbon mixed in the mixed heat storage medium may be a continuous series, a fixed length, or a flake-like material cut short.
In other words, the spirally curled metal fiber or metal ribbon is used in a form that fills the wall surface narrow space together with the heat storage medium.

Furthermore, the metal fibers and ribbons mixed in the mixed heat storage medium are manufactured with iron, chromium, nickel, copper, aluminum, etc. as the main component, reducing the friction loss of the solid surface and the affinity of the solid-liquid interface. Surface treatment for improving the surface may be performed. The metal fiber or metal ribbon used for the mixed heat storage medium is curled in a spiral shape, and its thermal diffusivity a is 0.1 to 100 [mm ² / s], that of the heat storage medium (for example, Greater than about 0.02 mm ² / s). Here, the thermal diffusivity is a physical property value representing the speed at which the heat of an object having a heat capacity spreads (diffuses) three-dimensionally due to heat conduction, and the density ρ [kg / m ³ ] of the object, the specific heat C “ Using [J / kgK] and thermal conductivity λ [W / m ² ], it is defined as a = λ / (ρ · C).

Since the metal fibers and metal ribbons embedded in the mixed heat storage medium have the above geometric shape and thermal characteristics, the following effects are exhibited, and the heat transfer effect and heat storage performance are higher than those of the heat storage medium alone. Play.
(1) Since the space expands three-dimensionally and is in contact with the heat storage medium, the effects of heat conduction, convection, and heat diffusion are improved.
(2) Since a metal material having a higher heat capacity than the heat storage medium is included, the heat storage amount (heat capacity) per unit volume is increased as compared with the case of the heat storage medium alone.
(3) Since it has a spirally curled shape, the capillary effect (liquid suction effect) acts, the liquid surface arrival position of the heat storage medium is increased, and the circulation force is improved.
(4) The surface area, specific volume, and porosity of the entire metal fiber or metal ribbon can be controlled by changing the number of metal fibers or metal ribbon, the spiral curl shape, and the spiral angle.

The regenerative exhaust heat recovery device according to the present invention is
An internal pressure regulating valve is provided in the ceiling portion of the wall surface narrow space or the inner wall side space,
The internal pressure adjustment valve
When the heat storage medium reaches a certain temperature or more and the volume increases, the inside of the wall surface narrow space or the inner wall side space becomes high pressure,
Exhaust the air stored in the narrow wall space or the inner wall side space,
When the volume of the heat storage medium decreases below a certain temperature and the inside of the wall surface narrow space or the inner wall side space becomes low pressure,
By sucking outside air from outside the wall surface narrow space or from the inner wall side space, the pressure inside the wall surface narrow space or the inner wall side space is kept constant.

When exhaust heat is transmitted from the high-temperature wall surface to the heat storage medium, the volume of the heat storage medium increases as the temperature rises. At this time, in a state where the wall surface narrow space or the inner wall side space is sealed, the wall surface narrow space or the inner wall side space becomes a high pressure state, which causes the wall surface to be deformed or damaged.
Furthermore, in the above-described invention in which the heat storage medium is circulated by a method in which the heat storage medium flows from the inner wall side space into the outer wall side space by utilizing the increase in liquid level (increase in volume) accompanying the temperature increase of the heat storage medium. It becomes impossible to circulate.

Therefore, the present invention is provided with an internal pressure adjustment valve so that the internal pressure in the narrow wall surface space or the inner wall side space can be adjusted. The internal pressure regulating valve is provided in a narrow wall surface or a ceiling part (gas phase space) of the inner wall side space, and is present in the narrow wall surface or in the inner wall side space when the heat storage medium reaches a certain temperature or increases in volume. When the gas is discharged and the volume of the heat storage medium is reduced below a certain temperature, the outside air is sucked from the outside of the wall surface narrow space or from the inside wall side space. By keeping the pressure in the space constant, for example, deformation or breakage of the wall surface that occurs due to high pressure is prevented, and the inner wall side is increased by utilizing the increase in liquid level (increase in volume) accompanying the temperature increase of the heat storage medium. The heat storage medium is circulated by a method in which the heat storage medium flows from the space into the outer wall side space.
In particular, in the invention in which the liquid level of the heat storage medium rises and the heat storage medium circulates as the temperature of the heat storage medium rises, the heat storage medium can perform natural circulation by the internal pressure adjustment valve.
In addition, by providing the internal pressure adjusting valve with an outside air releasing or stretchable bellows pack (bag), it is possible to maintain the inside of the wall surface space in an atmospheric pressure state.

The regenerative exhaust heat recovery device according to the present invention is
The heat transfer tube
The inside of the narrow wall surface or the inner wall side space provided outside the high temperature wall surface is spirally piped around the wall surface along the wall surface.

The working medium does not directly recover the exhaust heat transmitted from the high-temperature wall surface, but indirectly recovers it via the heat storage medium, but to efficiently recover the exhaust heat stored by the heat storage medium to the working medium. It is effective to increase the area where the heat transfer tube through which the working medium flows is in contact with the heat storage medium.
Therefore, the present invention is such that the heat transfer tube is piped spirally along the wall surface in the narrow wall surface space or the inner wall side space provided around the wall surface.

Combustion apparatus according to the present invention,
A combustion apparatus using a heat storage type exhaust heat recovery device that stores and recovers exhaust heat transmitted from a high temperature wall such as a combustion chamber or a chimney,
Outside the wall of the combustion chamber or chimney,
The heat storage type exhaust heat recovery device is provided.

The combustion apparatus which concerns on this invention is a combustion apparatus provided with the said thermal storage type waste heat recovery apparatus.
The heat storage type exhaust heat recovery device can be provided in a combustion device having a combustion chamber, a chimney, or the like.
The heat storage exhaust heat recovery device recovers the exhaust heat transferred from the high-temperature walls such as the combustion chamber and chimney of the combustion device, reducing the heat loss to the outside air and improving the combustion efficiency. Contributes to effective use.

The cogeneration system according to the present invention is:
The combustion device of the previous section;
A pump or compressor for pumping the working medium;
A turbine that drives a generator with a working medium that has become superheated steam (saturation temperature or higher) due to heat exchange with the heat storage medium;
It is composed of a generator and a condenser.

A cogeneration system according to the present invention is a cogeneration system using the combustion apparatus. A turbine (generator), condenser (cooler), pump or compressor is connected to the combustion device equipped with the above-mentioned heat storage type exhaust heat recovery device, and it exchanges heat with a high-temperature heat storage medium. The heated working medium is further heated to form superheated steam to drive the turbine, so that even a small-scale combustion device can stably generate superheated steam at 200 to 300 ° C. Even so, it becomes possible to construct a cogeneration system.

The heat storage type exhaust heat recovery apparatus according to the present invention uses two types of heat media, a “heat storage medium” having a high boiling point and a high heat capacity, and a “working medium” having a low boiling point, and exhaust heat transferred from a high-temperature wall surface. After the heat is stored in the heat storage medium, the working medium indirectly recovers the exhaust heat held by the heat storage medium.
Thereby, the following effects are exhibited.
(1) Even if water or a low boiling point or low temperature working medium is supplied into the apparatus, the working medium does not directly contact the high temperature wall surface. It is possible to avoid the situation of excessive reduction.
(2) The situation in which the temperature difference in the thickness direction of the combustion furnace wall surface does not suddenly increase, that is, the temperature difference in the wall thickness direction and the longitudinal direction decreases due to the presence of a high-temperature heat storage medium. Since the temperature gradient in the direction becomes gentle, it is possible to avoid a situation where the wall surface is deformed by thermal stress.
(3) Even if a change in the state of the working medium (pressure increase, dryout, bubble vibration, etc.) occurs, it is possible to avoid a situation in which they directly affect the combustion furnace wall surface.
(4) Since the heat transfer tube through which the working medium flows is arranged (immersed) in the heat storage medium, the heat of the working medium is not transmitted directly to the outside air, so the heat of the working medium is higher than that of the conventional exhaust heat recovery device. Loss is reduced and stable superheated steam can be obtained.

In addition, the heat storage type exhaust heat recovery device according to the present invention employs a configuration in which the liquid level of the heat storage medium rises by using a heat storage medium having a large coefficient of thermal expansion, and is convected and stirred by natural circulation. A system capable of temperature control can be configured without using a power source such as a pump or an expensive electrical sensor.
Therefore, it contributes to reduction of power consumption of the system.

Furthermore, the cogeneration system according to the present invention exhibits the following effects by adopting a configuration in which the exhaust heat stored in the heat storage medium is recovered by the working medium and becomes superheated steam to drive the turbine.
(5) Since the heat transfer tube through which the working medium flows is immersed in the heat storage medium, the working medium is not directly affected by the temperature fluctuation of the combustion furnace, and is a relatively stable and stable superheated steam. Can be obtained.
(6) Even if an operation for increasing the pressure or flow rate of the superheated steam at the turbine inlet is performed, the change in the temperature and pressure of the working medium does not affect the combustion furnace wall surface or the combustion chamber.
(7) Furthermore, by using water for cooling the heat radiating pipe, a system for simultaneously supplying electricity and hot water (cogeneration) can be constructed.
As described above, it is possible to provide an apparatus and a system that are more stable in heat and more excellent in heat control than conventional waste heat recovery apparatuses.

Configuration diagram showing outline of conventional exhaust heat recovery device The block diagram which shows the outline of the thermal storage-type waste heat recovery apparatus which concerns on Example 1. FIG. The block diagram which shows the outline of the heat storage type waste heat recovery apparatus which concerns on Example 2. FIG. The block diagram which shows the outline of the heat storage type waste heat recovery apparatus which concerns on Example 3. FIG. Schematic diagram showing the state where the heat storage medium is stored in an annular tube Schematic diagram showing how the heat storage medium stored in the annular tube starts to heat and a small circulating flow is generated in the tube A schematic diagram showing a state in which the heat storage medium stored in the annular pipe is heated and cooled, and an upward flow and a downward flow are generated in the pipe due to the density difference of the heat storage medium. The figure which showed the mixed heat storage medium of the state which mixed the metal ribbon in the heat storage medium typically Sectional drawing which shows the outline | summary of the experimental apparatus used in order to compare the liquid level rise rate of a thermal storage medium and a mixed thermal storage medium Graph comparing liquid level rise rate of heat storage medium and mixed heat storage medium A graph comparing the relationship between elapsed time and temperature change (heat storage amount and heat storage speed) during heater heating for heat storage media, mixed heat storage media, and water Sectional drawing which shows the outline of the combustion apparatus provided with the heat storage type waste heat recovery apparatus Sectional drawing which shows the outline of the thermal storage type waste heat recovery apparatus of the chimney part of FIG. Sectional drawing which expanded a part of the heat storage type exhaust heat recovery device of FIG. System diagram of cogeneration system equipped with heat storage type exhaust heat recovery device

FIG. 1 shows that a working medium 1 (water at around 20 ° C. or a low-boiling-point heat medium) is supplied to a combustion apparatus, and heat transferred from the wall surface is recovered while the working medium is in direct contact with a high-temperature wall surface. It is the block diagram which showed the outline of the conventional waste heat recovery apparatus which rotates a turbine with the generated superheated steam.

In the embodiment of FIG. 1, the working medium 1 directly touches the wall surface 2 of the combustion device, and therefore has the following problem.
(1) At the wall surface 2 portion where the heat medium 1 near normal temperature (about 20 ° C.) comes into contact, the working medium 1 sharply decreases the temperature of the wall surface 2, and the inner side (combustor side, high temperature) and the outer side ( Since the temperature difference (temperature gradient) increases between the heat medium side and the low temperature, the wall surface 2 is deformed by thermal stress.
(2) If the working medium 1 rapidly lowers the temperature of the wall surface 2 and the combustion heat is not sufficient, the combustion temperature in the combustion chamber is lowered, and there is a risk of causing harmful gas generation due to incomplete combustion.
(3) In a two-phase region where liquid and vapor are mixed, dryout may occur and the wall surface 2 may be burned out (burned out).

In the embodiment shown in FIG. 1, when the working medium 1 that has recovered heat from the wall surface 2 of the combustion device becomes high-temperature and high-pressure superheated steam 3 and is used as a mode for rotating the turbine 4, the following situation occurs.
(3) Since the amount of steam generated in the working medium 1 increases / decreases as the amount of heat generated in the combustion chamber increases / decreases, fluctuations in pressure and steam flow for driving the turbine 4 increase, and stable rotation speed cannot be maintained.
(4) An operation of adjusting the flow rate of the superheated steam 3 to keep the rotation speed of the turbine 4 constant by the flow rate adjusting valve 5 installed at the inlet of the turbine 4 is performed. A pressure fluctuation occurs, which affects the combustion conditions in the furnace, resulting in a decrease in operability.
(5) Since the pressure at the turbine inlet acts directly as a force on the combustion furnace wall surface, there is a risk that the wall surface may be deformed depending on the turbine inlet pressure. That is, the pressure at the turbine inlet is limited by the pressure resistance of the combustion furnace wall.

As a means for avoiding the above, a method of increasing the thickness of the member of the wall surface 2 and sufficiently maintaining the distance between the wall surface 2 and the heat source (flame) can be considered. However, when the thickness of the member is increased, the thermal resistance of the wall surface 2 is increased, and not only the amount of exhaust heat recovery is greatly reduced, but also the combustion apparatus is enlarged.

Furthermore, when a safety valve (valve) 6 is provided in the upper part of the flow path filled with the heat medium 1 and the pressure exceeds a set pressure value, a safety measure may be taken to release (vent) the steam to the outside air. However, it is desirable to avoid the release of the working medium to the outside as much as possible because it leads to a significant performance degradation particularly in a closed system, requiring refilling work and causing environmental pollution.

FIG. 2 is a configuration diagram illustrating an outline of the regenerative exhaust heat recovery apparatus according to the first embodiment.
The heat storage-type exhaust heat recovery apparatus according to the first embodiment is an apparatus that recovers and uses exhaust heat by using two types of heat medium, that is, a heat storage medium 7 having a high boiling point and a high heat capacity, and a working medium 8 having water or a low boiling point. It is. The heat storage medium 7 is a liquid whose boiling point at normal pressure is higher than that of water and whose volume increases as the temperature rises (volume ratio at 25 to 300 ° C. is 1.5 times or less than 1 at normal temperature). In the heat storage type exhaust heat recovery device, a wall surface narrow space 9 for storing the heat storage medium 7 is provided outside the high temperature wall surface 2 of the combustion apparatus, and the heat storage medium 7 is stored in the wall surface narrow space 9.
A heat transfer tube 10 is provided in the narrow wall surface 9 for storing the heat storage medium 7, and the working medium 8 circulates in the heat transfer tube.

With such a configuration, after the heat storage medium 7 collects and stores the exhaust heat transmitted from the high-temperature wall surface 2 of the combustion apparatus, the heat storage medium 7 transmits the exhaust heat stored in the heat storage medium 7 to the low boiling point working medium 8. And collect. Here, the low boiling point means a liquid having a saturation temperature of 100 ° C. or lower at a pressure of 0.1 MP (atmospheric pressure).
Thereby, since the working medium 8 does not contact the hot wall surface 2 of the combustion device directly, it is possible to avoid a situation in which the wall surface 2 of the combustion device or the temperature of the combustion chamber is rapidly lowered.

Further, according to the regenerative exhaust heat recovery device according to the first embodiment, the temperature difference (temperature gradient) between the thickness direction and the flow direction of the wall surface 2 portion is smaller than that of the conventional device (FIG. 1). Is not deformed by thermal stress, and there is no danger of the wall surface 2 being deformed or damaged by pressurization due to the excessive increase in pressure by the superheated steam 3 of the working medium 8.
Therefore, it is not necessary to make the wall surface 2 thick, and the turbine 4 can be rotated by setting a large pressure value at the inlet of the turbine 4.

Furthermore, by embedding metal fibers, metal ribbons, metal particles, or the like in the narrow wall surface 9 in which the heat storage medium 7 is circulated, heat transfer can be promoted and heat storage performance and temperature controllability can be improved. Is possible.

It is desirable that the outer wall of the wall surface narrow space 9 has heat insulation so as not to be affected by the outside air temperature.
An internal pressure adjusting valve 11 can be provided on the ceiling portion of the wall surface narrow space 9.
When the heat storage medium 7 is heated and the volume is increased, the internal pressure adjusting valve 11 discharges air stored in the wall surface narrow space 9, and when the heat storage medium 7 is cooled and the volume is decreased, the outside air is discharged from the outside of the wall surface narrow space 9. Inhale.
In this way, by keeping the pressure in the wall surface narrow space 9 constant, for example, deformation or breakage of the wall surface 2 caused by a high pressure state is prevented.
Moreover, the inside of the packed bed can be maintained in an atmospheric pressure state by providing the internal pressure adjusting valve 11 with an outside air releasing or stretchable bellows pack (bag).

FIG. 3 is a configuration diagram illustrating an outline of the regenerative exhaust heat recovery apparatus according to the second embodiment.
The heat storage-type exhaust heat recovery apparatus according to the second embodiment is an apparatus that recovers exhaust heat by using two types of heat media, a heat storage medium 7 having a high boiling point and a high heat capacity, and a working medium 8 having a low boiling point.
In the heat storage type exhaust heat recovery device, a wall surface narrow space 9 filled with the heat storage medium 7 is provided outside the high temperature wall surface 2 of the combustion device, and the heat storage medium 7 is naturally circulated in the wall surface narrow space 9.
The wall surface narrow space 9 in which the heat storage medium 7 is filled and circulated is divided into a high temperature wall surface side space (inner wall side space 13) and an outer wall side space of the wall surface narrow space (outer wall side space 14) by a partition wall 12 having heat insulation properties. It is divided into and.

Since the partition wall 12 is open above and below the narrow wall surface 9, the heat storage medium 7 that collects the exhaust heat transmitted from the high temperature wall surface 2 in the inner wall side space 13 is used as the temperature rises. When the volume increases and exceeds the partition wall 12, it flows into the outer wall side space 14 (right side in the figure).
When the heat storage medium 7 that has flowed into the outer wall side space 14 is radiated or cooled, the specific volume becomes smaller (the density becomes larger) and becomes a downward flow from below the partition wall 12 (near the bottom surface of the wall surface narrow space 9) to the inner wall. By flowing into the side space 13 and repeating this, the heat storage medium 7 circulates, and the temperature of the heat storage medium 7 can be kept constant or uniform.

The inner wall side space 13 through which the heat storage medium 7 circulates is provided with a heat transfer pipe 10 through which the working medium 8 circulates. The working medium 8 indirectly recovers exhaust heat from the heat storage medium 7 through the heat transfer pipe 10. .
Thereby, since the low temperature working medium 8 does not directly touch the high temperature wall surface 2 of the combustion apparatus, the temperature of the wall surface 2 of the combustion apparatus or the inside of the combustion chamber is lowered, or deformation or burning of the wall surface 2 occurs. Can be prevented.

According to the heat storage type exhaust heat recovery apparatus according to the second embodiment, the temperature difference (temperature gradient) of the wall surface 2 is smaller than that of the conventional apparatus (FIG. 1) and does not become extremely large. There is no risk of deformation due to stress, and there is no risk of the wall surface 2 being deformed or damaged by pressurization even if the pressure suddenly rises due to the superheated steam 3 (saturation temperature or higher) of the working medium 8.
Moreover, the temperature of the heat storage medium 7 is controlled to be constant by adopting a configuration in which the heat storage medium 7 naturally circulates between the inner wall side space 13 and the outer wall side space 14 as the temperature of the heat storage medium 7 itself increases. Therefore, the heat storage medium 7 can be controlled to a constant or desired temperature only by natural circulation without using an electrical temperature sensor or electric power.
Furthermore, it is not necessary to use a power source such as a pump for circulation, and an exhaust heat recovery device having a high energy saving effect can be provided.
Furthermore, it is possible to improve heat storage property and temperature controllability by embedding metal fibers, metal ribbons, metal particles or the like in the narrow wall surface 9 in which the heat storage medium 7 is circulated (FIGS. 10 and 11). reference).
The outer wall of the wall surface narrow space 9 may have an enlarged heat transfer surface such as a fin so that the heat of the heat storage medium can be radiated to the outside air.

FIG. 4 is a configuration diagram illustrating an outline of a heat storage type exhaust heat recovery device according to a third embodiment.
The heat storage type exhaust heat recovery apparatus according to the third embodiment includes three types of heat media: a heat storage medium 7 with a high boiling point and a high heat capacity, a working medium 8 with water or a low boiling point, and a refrigerant 17 that cools the heat storage medium 7. This is a device that collects and uses exhaust heat. The heat storage type exhaust heat recovery apparatus is provided with a wall surface narrow space 9 for circulating the heat storage medium 7 outside the high temperature wall surface 2 of the combustion apparatus, and the heat storage medium 7 and a refrigerant 17 such as water are circulated in the wall surface narrow space 9. , Heat exchange.

The wall surface narrow space 9 in which the heat storage medium 7 is circulated is divided by a partition wall 12 having heat insulation properties, on the high temperature wall surface 2 side of the combustion device (inner wall side space 13), and on the outer wall side of the wall surface narrow space 9 (outer wall side). It is partitioned into a space 14). The partition wall 12 is provided so that the heat storage medium 7 stored in the inner wall side space 13 does not flow from the inner wall side space 13 to the outer wall side space 14 beyond the partition wall 12. The partition wall 12 is formed with an opening 15 penetrating the inner wall side space 13 and the outer wall side space 14 above and below the partition wall 12. The outer wall side space 14 has an opening formed above the partition wall 12. A heat radiating pipe 16 that connects 15 and an opening 15 formed below the partition wall 12 is provided. The heat radiating pipe 16 is an annular pipe that connects the opening 15 formed above the partition wall 12 and the opening 15 formed below the partition wall 12 through the outer wall side space 14, and is a vertical pipe connected in the vertical direction. However, a spiral tube that spirally connects the inside of the wall surface narrow space 9 can also be used.

Since the refrigerant (water) 17 is circulated in the outer wall side space 14, the heat storage medium 7 circulates in the heat radiating pipe 16 piped in the outer wall side space 14. The heat is radiated or cooled down to return to the inner wall side space 13.
Then, the heat storage medium 7 repeats exhaust heat collection and heat release, so that the temperature in the apparatus is kept constant or uniform by natural circulation due to the density difference of the liquid, and the heat of the refrigerant (water) is used as hot water. be able to.
A heat transfer pipe 10 through which the working medium 8 circulates is piped in the inner wall side space 13 in which the heat storage medium 7 is filled and circulated, and the working medium 8 indirectly exhausts heat from the heat storage medium 7 via the heat transfer pipe 10. to recover.
Thereby, since the low temperature working medium 8 does not directly touch the high temperature wall surface 2 of the combustion apparatus, the temperature of the wall surface 2 of the combustion apparatus or the inside of the combustion chamber is lowered, or deformation or burning of the wall surface 2 occurs. Can be prevented.

According to the heat storage type exhaust heat recovery device according to the third embodiment, the temperature difference (temperature gradient) of the wall surface 2 portion is smaller than that of the conventional device (FIG. 1) and does not become extremely large. There is no risk of deformation due to stress, and there is no risk of the wall surface 2 being deformed or damaged by pressurization even if the pressure suddenly rises due to the superheated steam 3 (saturation temperature or higher) of the working medium 8.
Further, by adopting a configuration in which the heat storage medium 7 naturally circulates between the inner wall side space 13 and the outer wall side space 14 as the temperature of the heat storage medium 7 itself rises, the temperature of the heat storage medium 7 is made constant or uniform. Without using an electrical temperature sensor or electric power for control, the heat storage medium 7 can be controlled at a constant or uniform temperature only by natural circulation, and can be controlled not to cause an excessive temperature rise. In addition, it is not necessary to use a power source such as a pump, and an exhaust heat recovery device with high energy saving effect can be provided.
Further, the excess heat of the exhaust heat stored in the heat storage medium 7 is cooled in the outer wall side space 14, but the refrigerant (for example, water) 17 can be used as hot water by obtaining the exhaust heat.
Furthermore, by embedding metal fibers, metal ribbons, metal particles, etc. in the narrow wall surface 9 or the inner wall side space 13 in which the heat storage medium 7 is circulated, the heat transfer promotion effect, heat storage performance and temperature controllability are improved. (See FIGS. 10 and 11).
In addition, it is desirable that the outer wall of the wall surface narrow space 9 has heat insulation so as not to be affected by the outside air temperature.

The heat storage medium 7 of the heat storage type exhaust heat recovery apparatus according to the embodiment of FIGS. 3 and 4 naturally circulates between the inner wall side space and the outer wall side space based on the principle shown in FIGS.
5-7, the inside of the system is maintained at a constant pressure by the static pressure port 18 upward, and the left side in the figure of the annular tube (the inner peripheral wall surface of the tube has heat insulation) is the heating unit, It is the figure which showed typically the flow aspect and the liquid level rise of the heat storage medium 7 with the high boiling point and the high heat capacity with which the inside of a pipe | tube was filled with the right side in the figure as a cooling part.
That is, FIGS. 5 to 7 show the configuration of heat transfer between the inner wall space 13 and the outer wall space 14 in Example 2 (FIG. 3) and Example 3 (FIG. 4) partitioned by a heat insulating wall, and the liquid of the heat storage medium 7. It is the figure which modeled (simplified) and showed the aspect of the surface rise and the natural circulation.

FIG. 5 shows an annular tube filled with the heat storage medium 7.
The pipe is filled with a heat storage medium 7 in such an amount that the liquid level is located at a position lower than the height at which the left and right pipes communicate with each other.
The heat storage medium 7 is in an initial isothermal state in which no heat enters and exits.
When there is air in the upper space not filled with the heat storage medium 7 and the static pressure port 18 is open to the atmosphere, the system pressure is 1 atm.
The static pressure port 18 can also adjust the pressure in the system in a sealed state by connecting a stretchable container or the like (such as a bellows, a piston, or a Teflon (registered trademark) pack).

FIG. 6 is a schematic view showing a state where only the left side of the tube is heated.
Since the inner peripheral portion of the annular pipe is insulated, even if the left side of the pipe is heated, the heat is not directly transferred to the right side of the pipe. The heat storage medium 7 filled in the tube is, for example, a liquid heat medium having a high boiling point and a high heat capacity, such as silicon-based or oil-based, and the volume is about 20% while the temperature rises from 25 ° C. to 200 ° C. Has increased thermal expansibility.
Accordingly, when the left pipe in the figure is heated, the volume increases due to thermal expansion as the temperature rises, and the liquid level rises.
Further, in the vicinity of the heating surface, convection (small circulating flow) due to the density difference (temperature distribution) of the heat storage medium 7 occurs.

FIG. 7 is a schematic view showing a state in which the liquid level of the heat storage medium 7 rises as a result of continuing to heat the left pipe in the drawing, and the heat storage medium 7 continues to circulate in the annular pipe.
As the liquid level rises and the heat storage medium 7 fills the upper space, the annular tube forms a continuous flow path.
Then, when the heat storage medium 7 heated by the left pipe in the figure flows to the right pipe in the figure to be radiated and cooled, and cooled by the right pipe in the figure to reduce the specific volume (density increases), the heat storage medium 7 moves downward as a downward flow and returns to the left pipe in the figure.
By repeating this, the heat storage medium 7 circulates in the annular pipe.

When a system having a heating part and a cooling part is constructed using the heat storage medium 7 having fluidity, a high boiling point and a high thermal expansion coefficient, an upward flow due to expansion in the heating part and a downward flow due to contraction in the cooling part are generated. It is possible to construct an exhaust heat recovery device that can generate and realize fluid transportation (natural circulation) by a kind of thermal pumping mechanism.
When the heat storage medium 7 reaches a certain temperature, the temperature of the heat storage medium 7 is controlled by setting the filling rate of the heat storage medium 7 in advance so that the liquid level of the heat storage medium 7 rises and circulates in the annular pipe. It becomes possible to do.

Moreover, the mixed heat storage medium 26 in which the metal ribbon 25 spirally curled is mixed into the heat storage medium 7 can also be used.
FIG. 8 is a diagram schematically showing the mixed heat storage medium 26 in a state in which the metal ribbon 25 spirally curled is mixed into the heat storage medium 7.
The metal ribbon 25 mixed in the mixed heat storage medium in the figure is a metal ribbon having a square cross-sectional shape (that is, a thin ribbon-like thin wire, equivalent diameter De = 0.1 mm), and is curled spirally. They are assembled in a state and filled into a narrow wall surface in a lump shape.
Since the metal thin wires 25 having a higher thermal conductivity than the heat storage medium 7 are three-dimensionally distributed in the heat storage medium 7 in contact with the high-temperature heat transfer surface, it is more than the case of the heat storage medium alone. The heat diffusion rate is improved, and the temperature distribution in the medium is made uniform. In addition, since the fine line has a spirally curled geometric shape, the capillary effect (liquid suction effect) due to surface tension can be used as the liquid circulation force, that is, the force acting in the direction opposite to gravity.
The mixed heat storage medium 26 having such characteristics changes the surface area, specific volume, and porosity of the entire metal ribbon 25 by changing the number of the metal ribbons 25 to be mixed and the spiral curl shape, and changes the material. Thus, the thermal conductivity can be changed.

The relationship between the temperature of the heat storage medium and the expansion coefficient (liquid level height) needs to be quantified in advance using, for example, the apparatus shown in FIG. That is, the heat storage medium 7 is filled in the heat insulating container 28 that can visualize the liquid level height, and the temperature and the liquid level height of the heat storage medium 27 heated to a constant temperature using the heater 27 are measured. Then, based on the relationship (test curve) between the temperature of the heat storage medium and the expansion rate (liquid level rise rate), the filling amount to the actual machine is determined by estimation.

FIG. 10 is a graph showing the relationship between the temperature of the silicon-based heat storage medium and the liquid level increase rate measured using the apparatus of FIG. 9 and comparing the heat storage medium alone 7 and the mixed heat storage medium 26.
The liquid level increase rate was expressed by the relative ratio (h / h0) of the liquid level height h [mm] at each temperature to the height h0 [mm] at a temperature of 25 ° C. Further, “●” in the figure is the heat storage medium 7, and “■” in the figure is the mixed heat storage medium 26. The liquid level rise rate at a temperature of 250 ° C. is 1.22 (about 22% increase) for the heat storage medium alone, whereas it is about 1.35 (about 35% increase rate) for the mixed heat storage medium ■. is there. As described above, the reason why the mixed heat storage medium shows a higher liquid level rise rate than the single heat storage medium is because the metal fiber having a large thermal conductivity and thermal diffusivity is present in the medium, so the temperature distribution of the heat storage medium is made uniform. It is conceivable that the liquid suction effect (capillary effect) acts due to the presence of the spiral-shaped metal fiber. Therefore, in the present heat storage and recovery apparatus that controls the circulating temperature that covers the amount of exhaust heat stored according to the liquid level, the temperature can be controlled with higher accuracy by using a mixed heat storage medium having a large liquid level rise rate.

FIG. 11 shows the result of comparing the relationship between the heating time and temperature for the heat storage medium 7, the mixed heat storage medium 26, and water.
In the figure, “●” is the heat storage medium 7, “■” is the mixed heat storage medium 26, and “◯” is water.
According to this graph, the temperature rise of the heat storage medium 7 is higher than that of water, and the mixed heat storage medium 26 is further higher.
From this result, the heat storage medium 7 has higher heat storage performance than water. Moreover, there is an effect of improving the heat storage performance and the heat transfer performance further than the heat storage medium alone by mixing metal fibers having a large heat capacity and thermal diffusivity into the heat storage medium.

FIG. 12 is a cross-sectional view showing an outline of a combustion apparatus provided with a heat storage type exhaust heat recovery apparatus.
The heat storage type exhaust heat recovery device can be provided outside the wall surface of various combustion devices.
In the embodiment of FIG. 12, a regenerative exhaust heat recovery device is installed outside the chimney 20 of the combustion device and the wall surface 2 of the combustion chamber 21. This is because the chimney 20 of the combustion device is replaced with an economizer or an evaporator. In this embodiment, the combustion chamber 21 of the combustion apparatus is used as a superheater.

The heat storage type exhaust heat recovery device is not limited to the chimney 20 or the combustion chamber 21 and can be provided anywhere as long as it is a high-temperature wall surface portion. The heat storage type exhaust heat recovery device includes a wall surface narrow space 9 provided outside the high temperature wall surface 2. The wall surface narrow space 9 includes an inner wall side space 13 and an outer wall side space 14. The inner wall side space 13 and the outer wall side space 14 are partitioned by a partition wall 12 having heat insulation properties. The heat storage medium 7 circulates in the inner wall side space 13, and the refrigerant 17 circulates in the outer wall side space 14 adjacent to the outside.

FIG. 13 is an enlarged cross-sectional view of the chimney portion of FIG.
A heat radiating pipe 16 having fins 19 is piped in the outer wall side space 14, and the heat storage medium 7 flows from the inner wall side space 13 to the heat radiating pipe 16 through the opening 15 and circulates in the heat radiating pipe 16. It is cooled by the refrigerant (water) circulating through 14 (see also FIGS. 13 and 14).
The cooled heat storage medium 7 flows into the inner wall side space 13 from the opening 15 below the partition wall 12, and this is repeated, whereby the heat storage medium 7 circulates and keeps the temperature of the heat storage medium 7 constant or uniform. be able to.
That is, in this embodiment, by keeping the temperature of the heat storage medium 7 as desired, even in a small-scale combustion apparatus with a large amount of exhaust heat, heat is stably secured in a leveled state with a small temperature variation. it can.

The ceiling portion of the inner wall side space 13 is provided with a static pressure port 18 for mounting the inner pressure regulating valve 6. When the heat storage medium 7 is heated and its volume is increased, air existing in the inner wall side space 13 is discharged. When the heat storage medium 7 is cooled and the volume is reduced, the inner wall side space 13 is in a low pressure state and sucks air from the outside.
In this way, by keeping the pressure in the inner wall side space 13 constant, for example, deformation or breakage of the wall surface 2 caused by a high pressure state is prevented.

In the inner wall side space 13, the heat transfer tube 10 is piped in a spiral shape. The working medium 8 circulates in the heat transfer tube 10, during which the exhaust heat accumulated in the heat storage medium 7 is transmitted and recovers the exhaust heat. The working medium 8 passes through the region of the combustion chamber to become superheated steam 3 and drives the turbine 4 to be used for power generation (see FIG. 15). Since the working medium 8 indirectly recovers the exhaust heat through the heat storage medium, the working medium 8 does not directly touch the high temperature wall surface 2.
Thereby, the temperature inside the wall surface 2 of the combustion apparatus and the combustion chamber 21 is not lowered, and there is no concern that the wall surface is deformed by thermal stress.
Even if the working medium 8 becomes superheated steam 3 and the inside of the heat transfer tube suddenly becomes high pressure, the superheated steam 3 does not directly touch the wall surface 2, so there is no danger of deforming or damaging the wall surface 2. Even if the dry-out occurs, it does not affect the wall surface 2 only because it occurs in the heat transfer tube 10, so there is no risk of burning the wall surface 2.

According to the combustion device provided with the heat storage type exhaust heat recovery device, the heat storage medium 7 having a high boiling point and a high heat capacity circulates outside the wall surface 2 of the combustion device so as to cover the combustion device. Become bigger. Therefore, if the regenerative exhaust heat recovery device is installed in a small-scale combustion device that is easily affected by the outside air environment, the effect of suppressing thermal fluctuations due to changes in the combustion state in the combustion chamber and changes in the outside air temperature is exhibited.
Further, since the heat storage medium 7 having a high heat capacity covers the entire heat transfer tube 10 and heat can be stably supplied to the working medium flowing therethrough, stable supply of superheated steam, that is, stable driving of the turbine and electric stability Can contribute to supply.
In addition, by using the refrigerant | coolant (water) 17 used in order to cool the thermal storage medium 7 as warm water, it can contribute to the further effective utilization of heat, and the improvement of system efficiency.

It is desirable that the outer wall of the wall surface narrow space 9 has heat insulation so as not to be affected by the outside air temperature.
Similarly, the partition wall 12 that partitions the wall surface narrow space 9 into the inner wall side space 13 and the outer wall side space 14 does not transmit heat through the partition wall 12 between the inner wall side space 13 and the outer wall side space 14. It is desirable to have heat insulation.

13 is a cross-sectional view schematically showing a heat storage type exhaust heat recovery device provided outside the wall of the chimney of the combustion apparatus of FIG. 12, and FIG. 14 is a heat storage type provided outside the wall of the chimney of the combustion apparatus of FIG. It is sectional drawing to which some exhaust heat recovery apparatuses were expanded.

The heat storage type exhaust heat recovery device can be provided outside the wall surface 2 of the chimney 20 of the combustion device.
In the chimney 20, high-temperature exhaust gas moves from the lower side to the upper side in the figure, and the inner wall 2 of the chimney 20 is at a high temperature.
The heat storage type exhaust heat recovery device was partitioned into an inner wall side space 13 (space on the wall surface 2 side of the chimney 20) and an outer wall side space 14 (space on the outer wall side of the wall surface narrow space 9) by the partition wall 12 having heat insulation properties. It consists of a wall surface sandwiching space 9.

A heat transfer pipe 10 for circulating the working medium 8 is spirally piped around the chimney 20 along the wall surface 2 of the cylindrical chimney 20 in the inner wall side space 13.
The outer wall side space 14 is provided with an annular heat radiating pipe 16 that connects the opening 15 formed above the partition wall 12 to the opening 15 formed below the partition wall 12 through the outer wall side space 14. .
The heat radiating pipe 16 is provided with one or more vertical pipes that vertically connect an opening 15 formed above the partition wall 12 to an opening 15 formed below the partition wall 12 at an arbitrary location around the chimney 20. Alternatively, the entire periphery of the chimney 20 may be formed in a layered or double tube manner from the opening 15 formed above the partition wall 12 to the opening 15 formed below the partition wall 12.

In the inner wall side space 13, the heat storage medium 7 is stored, and when the heat storage medium 7 stores the exhaust heat transmitted from the wall surface 2 of the chimney 20 and becomes high temperature, the volume of the heat storage medium 7 expands and the liquid level is increased. To rise. When the liquid level of the heat storage medium 7 rises, the inner wall side space 13 and the heat radiating pipe 16 form a continuous flow path.
Then, when the liquid level of the heat storage medium 7 rises, the heat storage medium 7 stored in the inner wall side space 13 is positioned at the position of the opening 15 formed above the partition wall 12 while generating buoyancy, that is, upward flow due to thermal expansion. And reaches the heat radiating pipe 16 piped in the outer wall side space 14 from the opening 15.

The ceiling portion of the inner wall side space 13 is provided with a static pressure port 18 for mounting the inner pressure regulating valve 6, and when the heat storage medium 7 is heated and the volume increases, the air stored in the inner wall side space 13 is discharged. When the heat storage medium 7 is cooled and the volume is reduced, outside air is sucked from outside the inner wall side space 13.
In this way, by keeping the pressure in the inner wall side space 13 constant, for example, deformation or breakage of the wall surface 2 caused by a high pressure state is prevented.

A refrigerant (water) 17 circulates in the outer wall side space 14 where the heat radiating pipe 16 is piped, and cools the heat storage medium 7 flowing in the heat radiating pipe 16.
The heat dissipating pipe 16 has heat dissipating fins 19 formed around it, and promotes cooling of the heat storage medium 7.
The heat storage medium 7 cooled by the heat radiating pipe 16 flows into the inner wall side space 13 from the opening 15 formed below the partition wall 12 while generating a downward flow.
By repeating this, the heat storage medium 7 naturally circulates between both spaces without applying pump power from the outside, and heating and cooling are continuously performed, so that the temperature is kept constant or uniform. .

The exhaust heat stored by the heat storage medium 7 is finally transmitted to the working medium 8 that circulates in the heat transfer pipe 10 piped in the inner wall side space 13.
In this way, the working medium 8 does not directly recover the exhaust heat transmitted from the high temperature wall surface 2 but indirectly recovers it via the heat storage medium 7.

When the filling amount of the heat storage medium 7 is increased, the inner wall side space 13 and the heat radiating pipe 16 form a continuous flow path at an early stage to start circulation, so that the temperature of the heat storage medium 7 is kept low. Further, when the filling amount of the heat storage medium 7 is reduced, it takes a long time for the inner wall side space 13 and the heat radiating pipe 16 to form a continuous flow path, but heat is stored until the heat storage medium 7 starts to circulate. As a result, the heat storage medium 7 can be kept at a high temperature.
Thus, by changing the filling amount (that is, the liquid level height) of the heat storage medium 7, the temperature and the heat storage amount of the heat storage medium 7 that stores the exhaust heat can be controlled.
According to the present embodiment, since the periphery of the high temperature wall surface 2 of the chimney 20 is covered with the heat storage medium 7 having a high heat capacity, the heat capacity becomes larger than that of the conventional apparatus, and the exhaust heat recovery rate is improved. In addition, since the entire heat transfer tube 10 is immersed in the heat storage medium 7 having a high heat capacity, and is covered and kept warm, it is possible to reduce that the working medium is directly affected by fluctuations in heat generated in the combustion chamber and the outside air environment, and exhaust heat. Contributes to the stable supply and use of It is desirable that the outer wall of the wall surface narrow space 9 has heat insulation so as not to be affected by the outside air temperature.

FIG. 15 is a main system diagram of a cogeneration system including a heat storage type exhaust heat recovery device, and the direction in which the working medium and the refrigerant flow is indicated by arrows in the drawing.
A combustion device provided with a heat storage type exhaust heat recovery device in a chimney 20 and a combustion chamber 21, a turbine 4 (generator 24), a condenser (cooler) 22, a pump or a compressor 23 are connected in series. The working medium 8 is sent to a heat storage type exhaust heat recovery device provided on the wall surface 2 of the chimney 20 by a pump or a compressor 23 and becomes saturated steam by exchanging heat with the high temperature heat storage medium 7. The working medium 8 that has become saturated steam is sent to a heat storage type exhaust heat recovery device provided on the wall surface 2 of the combustion chamber 21 and further heated to become superheated steam 3 to drive the turbine 4.
Thereafter, the working medium 8 is sent to the condenser 22 and cooled.

According to the present embodiment, even a small-scale combustion apparatus can stably generate superheated steam 3 at 200 to 300 ° C., and even a small-scale combustion apparatus can construct a cogeneration system. become.
Further, since the working medium 8 that becomes the superheated steam 3 circulates in the heat transfer tube 10 and does not directly touch the wall surface 2 of the combustion chamber 21, the wall surface 2 is not deformed or damaged. The pressure value at the inlet of the turbine 4 can be set to be equal to or higher than the pressure resistance value of the wall surface 2 of the combustion chamber 21, and as a result, the steam pressure can be effectively utilized for power generation.

As described above, according to the present invention, the heat medium whose volume increases as the temperature rises is used to realize natural circulation of the heat medium by exhaust heat drive, and is efficient even for exhaust heat with large temperature fluctuations. Since heat can be well recovered and stored, a heat storage type exhaust heat recovery device that contributes to a stable supply of heat, a combustion device using the same, and a cogeneration system can be provided.

Explanation of sign

DESCRIPTION OF SYMBOLS 1 Working medium 2 Combustion apparatus wall surface 3 Superheated steam 4 Turbine 5 Flow rate adjusting valve 6 Pressure adjusting valve or safety valve 7 in the wall sandwiching space 7 Heat storage medium 8 Working medium 9 Wall narrow space 10 Heat transfer tube 11 Valve or safety valve 12 Bulkhead 13 Inner wall side space 14 Outer wall side space 15 Opening portion 16 Radiation pipe 17 Refrigerant (water, etc.)
18 Static pressure port 19 Fin 20 Chimney 21 Combustion chamber 22 Condenser (cooler)
23 Compressor or pump 24 Generator 25 Metal ribbon or metal fiber 26 Mixed heat storage medium 27 Heater 28 Thermal insulation container

Claims (9)

A heat storage type exhaust heat recovery device for storing and recovering exhaust heat transmitted from a high temperature wall surface of a combustion device,
Thermal storage waste heat recovery equipment
It consists of a narrow wall surface for storing or circulating a heat storage medium provided outside the high temperature wall surface,
A heat transfer tube for circulating the working medium is installed in the narrow wall surface,
By storing or circulating the heat storage medium in the narrow wall surface, and circulating the working medium in the heat transfer tube,
A heat storage-type exhaust heat recovery apparatus, wherein the working medium recovers indirectly through a heat storage medium rather than directly recovering the exhaust heat transmitted from the high-temperature wall surface. A heat storage type exhaust heat recovery device for storing and recovering exhaust heat transmitted from a high temperature wall surface of a combustion device,
Thermal storage waste heat recovery equipment
It consists of a narrow space on the outside of the hot wall,
The wall surface narrow space is partitioned into a high temperature wall surface space (inner wall side space) and an outer wall side space (outer wall side space) of the wall surface narrow space by a partition that opens above and below the space.
In the inner wall side space, a heat transfer tube for circulating the working medium is installed,
When the heat storage medium stored in the inner wall side space stores exhaust heat and becomes high temperature, the heat storage medium flows from the opening part above the partition wall to the outer wall side space and is cooled, and returns from the opening part below the partition wall to the inner wall side space. In this case, the exhaust heat is stored again to become a high temperature, and this is repeated so that it circulates in both spaces, and the heat transfer pipe that is piped to the inner wall side space where the heat storage medium controlled to a constant temperature circulates by this circulation In addition, by circulating the working medium,
A heat storage-type exhaust heat recovery apparatus, wherein the working medium recovers indirectly through a heat storage medium rather than directly recovering the exhaust heat transmitted from the high-temperature wall surface. A heat storage type exhaust heat recovery device for storing and recovering exhaust heat transmitted from a high temperature wall surface of a combustion device,
Thermal storage waste heat recovery equipment
It consists of a narrow space on the outside of the hot wall,
The wall surface narrow space is partitioned by a partition wall into a high temperature wall surface space (inner wall side space) and an outer wall side space (outer wall side space) of the wall surface narrow space,
In the inner wall side space, a heat transfer pipe for circulating the working medium is piped,
In the outer wall side space, in order to transfer and circulate the heat storage medium in the inner wall side space into the outer wall side space, an opening formed in the lower part of the partition through the outer wall side space from the opening formed in the upper part of the partition wall. An annular radiating pipe is connected,
When the heat storage medium stored in the inner wall side space stores the exhaust heat and becomes high temperature, the heat storage medium is cooled while flowing through the heat radiating pipe piped in the outer wall side space from the opening formed above the partition wall. Then, it returns to the inner wall side space from the opening formed below the partition wall, accumulates the exhaust heat again and becomes high temperature, and this is repeated to circulate between both spaces, and this circulation makes the temperature constant (desired) By circulating the working medium in the heat transfer pipe piped in the inner wall side space so as to come into contact with the controlled heat storage medium,
A heat storage type exhaust heat recovery apparatus, wherein the working medium recovers indirectly through the heat storage medium and the heat transfer tube wall surface rather than directly recovering the exhaust heat transferred from the high temperature wall surface. The heat storage medium circulating through the inner wall side space is
It is a heat medium composed of a liquid whose boiling point at normal pressure is higher than that of water and whose volume increases as the temperature rises (volume ratio at 25 to 300 ° C. is 1.5 times or less than 1 at normal temperature),
The heat storage medium (initial state) before storing the exhaust heat is stationary at a position where the liquid surface, that is, the gas-liquid interface is lower than the opening or opening part above the partition wall, but the temperature rises after storing the exhaust heat As the volume expands along with the liquid level rises toward the opening or opening part above the partition wall,
When the desired temperature is reached, the heat storage medium flows into the outer wall side space from the opening portion above the partition wall or into the heat radiating pipe piped into the outer wall side space from the opening portion formed above the partition wall, By circulating between the space and the outer wall side space so that heat is radiated or cooled in the outer wall side space,
The regenerative exhaust heat recovery apparatus according to claim 2 or 3, wherein the temperature of the heat storage medium that recovers and stores the exhaust heat can be controlled. The heat storage medium circulating through the inner wall side space is
A heating medium composed of a liquid whose boiling point at normal pressure is higher than that of water and whose volume increases as the temperature rises (volume ratio at 25 to 300 ° C. is 1.5 times or less than 1 at normal temperature) is spiral. Is a mixed heat storage medium in which curled metal fibers and metal ribbons are mixed,
Before storing the exhaust heat, the liquid level of the heat storage medium lower than the opening or the opening part above the partition wall rises as the volume expands as the temperature rises after storing the exhaust heat. In the case where it becomes higher than the opening or opening part above the partition wall,
When a certain temperature is reached, the heat storage medium flows into the outer wall side space from the opening part above the partition wall or into the heat radiating pipe piped into the outer wall side space from the opening part formed above the partition wall, and the inner wall side space. By circulating between the outer wall side space and the outer wall side space so that heat is radiated or cooled in the outer wall side space,
The regenerative exhaust heat recovery apparatus according to claim 2 or 3, wherein the temperature of the heat storage medium that recovers and stores the exhaust heat can be controlled. An internal pressure regulating valve is provided in the ceiling portion of the wall surface narrow space or the inner wall side space,
The internal pressure adjustment valve
When the heat storage medium reaches a certain temperature or more and the volume increases, the inside of the wall surface narrow space or the inner wall side space becomes high pressure,
Exhaust the air stored in the narrow wall space or the inner wall side space,
When the volume of the heat storage medium decreases below a certain temperature and the inside of the wall surface narrow space or the inner wall side space becomes low pressure,
The heat storage type according to any one of claims 1 to 5, wherein the pressure in the wall surface narrow space or the inner wall side space is kept constant by sucking outside air from outside the wall surface narrow space or from the inner wall side space. Waste heat recovery device. The heat transfer tube is
7. The pipe according to claim 1, wherein the pipe is spirally piped around the wall surface in a narrow wall surface space or an inner wall side space provided outside the high temperature wall surface. The regenerative exhaust heat recovery device described. A combustion apparatus using a heat storage type exhaust heat recovery device that stores and recovers exhaust heat transmitted from a high temperature wall such as a combustion chamber or a chimney,
Outside the wall of the combustion chamber or chimney,
A combustion apparatus comprising the regenerative exhaust heat recovery apparatus according to any one of claims 1 to 7. The combustion device of the previous section;
A pump or compressor for pumping the working medium;
A turbine that drives a generator with a working medium that has become superheated steam (saturation temperature or higher) due to heat exchange with the heat storage medium;
A cogeneration system comprising a generator and a condenser.

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