JP2006046674A - Latent heat storage system, latent heat storage method, and sorption and desorption tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and compact latent heat storage system capable of using waste heat of 100°C or lower, a latent heat storage method, and a sorption and desorption tank. <P>SOLUTION: The latent heat storage system 10 having the sorption and desorption tank 11, a thermal storage tank 18, and a water vapor piping 26 connecting both tanks is composed of a sorption and desorption agent 12 carrying out sorption and desorption of water in the sorption and desorption tank 11, a heat exchanger 14 carrying out heat exchange of heat of sorption or desorption with heat of the outside, and a water vapor permeating means 13 for permeating and vaporizing water vapor from the heat storage tank 18 after it is condensed, and uniformly supplying it to the sorption and desorption agent 12. The heat storage tank 18 is composed of a cold storage agent 19 containing water, a water vapor permeating means 20 for allowing permeation and vaporization of only water from the cold storage agent 19, a heat exchanger 21 carrying out heat exchange between heat of vaporization and heat of the outside, and a heat exchanger 22 condensing the water vapor from the sorption and desorption agent 12, circulating it to the cold storage agent 19, and carrying out heat exchange between heat of condensation and heat of the outside. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a latent heat storage system, a latent heat storage method, and a sorption / desorption tank using sorption / desorption heat of a sorbent / desorbent, for example, distributed power sources (fuel cells, micro gas turbines, gas engines, etc.) and factories (incinerators, etc.). , A latent heat storage system that functions as a cold heat source and a heat source by effectively using waste heat of a relatively low temperature of about 30 ° C. to 100 ° C. discharged from hot springs and households (hot wastewater such as baths, exhaust gas), It is a latent heat storage method and a sorption / desorption tank. In addition, for example, the present invention relates to a latent heat storage system, a latent heat storage method, and a sorption / desorption tank to which a compression heat pump using nighttime power can be applied.

  International arrangements for global warming gas emission regulations at the 3rd Conference of the Parties to the United Nations Framework Convention on Climate Change (COP3) held in Kyoto in 1997, the implementation of the revised Energy Conservation Law in 1999, and rising crude oil prices, etc. Therefore, there is a very strong social demand for resource and energy conservation in Japan.

  In terms of policy, various deregulation measures for energy supply such as electricity and gas, promotion of the use of renewable energy with low environmental impact and unused energy such as exhaust heat, and assistance for higher efficiency of conventional energy use The construction and proposal of new energy systems are being promoted, such as the development of systems.

  In particular, in the development of small distributed cogeneration systems using micro gas turbines and fuel cells, which are the core of the next generation energy system revolution, effective use of low-level thermal energy emitted from these systems Method development is an important issue.

  Examples of conventional low-temperature waste heat recovery technology include an adsorption / desorption heat pump system using silica gel, zeolite, and activated carbon. This system uses an adsorption / desorption reaction with a substance having the ability to adsorb / desorb water vapor such as silica gel, and the detailed system configuration is large. It stores an adsorption / desorption tank that performs an adsorption / desorption process, and desorbed water (latent heat medium). It consists of two zones with a heat storage tank.

  The two zones are connected in a reduced pressure (vacuum) state by a gas pipe, and heat storage and heat collection are performed by moving water vapor (latent heat medium) in the pipe. The adsorption / desorption tank is provided with a heating device (heat exchanger or heater) for desorbing the adsorption medium from silica gel or the like, and a heat exchanger for recovering the adsorption heat generated in the adsorption process. In addition, the heat storage tank is provided with a condenser for condensing moisture moved from the adsorption / desorption tank in the desorption process, and a heat collecting heat exchanger for collecting cold heat generated when the medium evaporates in the adsorption process. Yes.

JP 9-313903 A JP-A-9-131516 JP 59-179112 A JP 59-147605 A JP 59-109203 A

<Problems of latent heat storage system>
In the consumer and industrial sectors, the shift to cogeneration and distributed power generation (cogeneration) is progressing with the aim of saving energy. However, even in such a situation, a problem for energy saving is that low-energy waste heat of 100 ° C. or less is not effectively used.

  In anticipation of the future, small distributed power sources such as polymer electrolyte fuel cells (PEFC), micro gas turbines, and micro gas engines, which are expected to have significant energy saving effects from the perspective of overall thermoelectric thermal efficiency, are used in the consumer sector (household (1-5 kW)) It is thought that it will spread dramatically in business use (10 to several tens of kW).

  In such a distributed power source, waste heat is built on the premise that it will be used in the form of hot water or steam, but when the power load is high, heat is surplus from the balance of thermoelectric demand and remains unused. There is concern that it will actually reduce the overall efficiency and not contribute to energy saving.

  Thus, the strong need for the effective use of low energy waste heat still appears in the civilian or industrial sectors. However, the current technical problem is that a heat system that efficiently recovers low-energy waste heat cannot be constructed.

  The reason behind the delay in the introduction and spread of latent heat storage systems is a compact, inexpensive, high-density, high-performance, easy-to-use adsorption / desorption tank and heat storage tank, even though the latent heat storage system is an active energy-saving technology. This is due to the fact that creative research and development for the development of a latent heat storage system integrating these was not conducted.

<Subjects for latent heat storage systems, especially adsorption / desorption tanks>
That is, in the conventional adsorption / desorption heat pump system described above, the temperature level of available waste heat is about 150 ° C., and there is a problem that the efficiency of the system is significantly reduced at a temperature level lower than this. This is derived from the performance of the adsorption / desorption material (silica gel, zeolite, activated carbon, etc.). Moreover, since the mass-specific adsorption capacity of the adsorption / desorption substance is low, the system is enlarged.

  Also, in the adsorption process, when the water vapor moving from the heat storage tank is adsorbed to the adsorption / desorption material filled in the tank, it is difficult for the water vapor to uniformly diffuse into the adsorption / desorption material. There is a problem that it cannot be used.

<Subjects for latent heat storage systems, especially heat storage tanks>
Moreover, since the cold storage density of the water which is a latent heat medium stored in the heat storage tank is low, it is necessary to prepare a large amount of water, leading to enlargement of the heat storage tank. Furthermore, when components other than moisture contained in the latent heat medium leak from the heat storage tank and enter the sorption / desorption tank, the performance of the sorption / desorption agent may be reduced.

  The present invention has been made in view of the above situation, and can use low-temperature waste heat, for example, waste heat of 100 ° C. or less (unused waste heat such as low-temperature steam and drain), and is inexpensive and compact. An object is to provide a latent heat storage system of performance, a latent heat storage method, and a sorption / desorption tank. In addition, this will contribute to resource and energy conservation and environmental conservation, and contribute to the effective use of low-level thermal energy discharged from distributed power sources, etc., which are expected to spread rapidly in the future as a global trend. Objective.

<Latent heat storage system>
The latent heat storage system according to the present invention for solving the above problems is as follows.
A latent heat storage system having a sorption / desorption tank and a heat storage tank,
The sorption / desorption tank condenses water vapor from the heat storage tank, a sorption / desorption agent for sorption and desorption of water, first heat exchange means for exchanging heat at the time of sorption or desorption with external heat, and the like. A first water vapor permeation means that permeates and evaporates and then supplies the sorbent / desorbent substantially uniformly.
The heat storage tank contains water, a cold storage agent that evaporates and condenses the water, second heat exchange means that exchanges heat during the evaporation with external heat, and condenses water vapor from the sorbent / desorbent. And a third heat exchanging means for exchanging the heat at the time of the condensation with the external heat and circulating to the cold storage agent.

  Compared to conventional silica gels and zeolites, it is possible to operate at low temperatures, and by adopting an organic sorbent / desorbent with a large amount of heat storage, the sorption / desorption temperature is extremely low, ranging from about 30 ° C to 100 ° C. Enables operation in the region and improves mass ratio or volume ratio sorption / desorption capability.

  In addition, the water vapor from the heat storage tank is not directly supplied to the adsorption / desorption agent in the sorption / desorption tank, but is supplied through a water vapor transmission means that once condenses moisture (latent heat medium) and transmits / evaporates only water. Accordingly, it is possible to diffuse moisture substantially uniformly into the sorbent / desorbent. This also greatly reduces the resistance to material movement in the sorption / desorption tank.

In the latent heat storage system,
The said heat storage tank is a latent heat storage system characterized by having the 2nd water vapor permeation | transmission means which permeate | transmits and evaporates only water from the said cool storage agent.

  Furthermore, by applying a water vapor transmission means in the heat storage tank, only moisture is moved from the heat storage tank to the sorption / desorption tank, and components other than water contained in the cool storage agent are prevented from leaking from the heat storage tank. It makes it possible to effectively transmit the latent heat of vaporization of water to the cold storage agent.

In the latent heat storage system,
Having a space between the sorption / desorption agent and the first water vapor transmission means;
The water vapor that has permeated and evaporated through the first water vapor transmission means is substantially uniformly supplied to the sorbent / desorbent via the space, and water desorbed from the sorbent / desorbent is supplied from the space to the heat storage tank. It is a latent heat storage system characterized by moving.

In the latent heat storage system,
The cold storage agent is a latent heat storage system characterized by containing an emulsion.

  By further mixing an emulsion (for example, microcapsule) into the cold storage agent containing water, the heat storage density of the cold storage agent is improved by utilizing the solid-liquid phase change of the emulsion. As the emulsion, it is preferable to use a low temperature coagulation type emulsion.

<Latent heat storage method>
The latent heat storage method according to the present invention for solving the above problems is as follows.
A latent heat storage method for performing a sorption process and a desorption process using a sorption / desorption tank and a heat storage tank,
The sorption step evaporates water from a regenerator containing water in the heat storage tank, exchanges heat at the time of the evaporation with external heat, and transmits water vapor from the heat storage tank to the first water vapor. Latent heat, characterized in that it is substantially uniformly sorbed to the sorbent / desorbent in the sorption / desorption tank by being permeated / evaporated after being condensed by means, and exchanging the heat during the sorption with external heat. It is a heat storage method.

In the latent heat storage method,
In the desorption step, water is desorbed from the sorption / desorption agent in the sorption / desorption tank, the heat during the desorption is exchanged with external heat, and water vapor from the sorption / desorption tank is condensed, It is a latent heat storage method characterized by circulating to a cool storage agent in a heat storage tank and exchanging heat at the time of condensation with external heat.

In the latent heat storage method,
In the latent heat storage method, only the water is transmitted and evaporated by the second water vapor transmission means when the water from the cold storage agent is evaporated in the sorption step.

In the latent heat storage method,
Having a space between the sorption / desorption agent and the first water vapor transmission means;
The water vapor that has permeated and evaporated through the first water vapor transmission means is substantially uniformly supplied to the sorbent / desorbent via the space, and water desorbed from the sorbent / desorbent is supplied from the space to the heat storage tank. It is a latent heat storage method characterized by moving.

In the latent heat storage method,
The cold storage agent is a latent heat storage method characterized by containing an emulsion.

<Desorption / desorption tank>
The sorption / desorption tank according to the present invention for solving the above problems is as follows.
A sorption / desorption tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A sorption / desorption agent for sorption and desorption of water, the heat exchange means for exchanging heat at the time of sorption or desorption with external heat, and permeating and evaporating after condensing water vapor from the outside It is a sorption / desorption tank characterized by having a water vapor transmission means for supplying the sorption / desorption agent substantially uniformly.

In the above sorption / desorption tank,
There is a space between the sorption / desorption agent and the water vapor transmission means,
The water vapor that has permeated and evaporated through the water vapor transmission means is supplied to the sorbent / desorbent substantially uniformly through the space, and the water desorbed from the sorbent / desorbent moves from the space to the outside. It is a sorption / desorption tank characterized by.

The sorption / desorption tank according to the present invention for solving the above problems is as follows.
A sorption / desorption tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A water vapor introduction part for introducing water vapor from the outside, and one or a plurality of sorption / desorption tubes provided in the water vapor introduction part,
The sorption / desorption tube has a double-pipe structure composed of an inner tube and an outer tube,
The inner pipe is constituted by an outer part constituted by a sorption / desorption agent for sorption and desorption of water, and an inner part constituted by the heat exchange means for exchanging heat at the time of the sorption or desorption with external heat. And consist of
The outer pipe is a sorption / desorption tank characterized in that it is a water vapor permeation means for condensing and evaporating the water vapor introduced into the water vapor introduction part and supplying it substantially uniformly to the sorbent / desorbent.

The sorption / desorption tank according to the present invention for solving the above problems is as follows.
A sorption / desorption tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A portion through which heat from the outside flows, and one or a plurality of sorption / desorption tubes provided in the portion through which the heat flows,
The sorption / desorption tube has a double-pipe structure composed of an inner tube and an outer tube,
The outer tube includes an inner part constituted by a sorption / desorption agent that sorbs and desorbs water, and an outer part constituted by the heat exchange means that exchanges heat at the time of sorption or desorption with external heat. And consist of
The inner pipe is a water vapor introduction part that introduces water vapor from the outside into the pipe, condenses the water vapor introduced into the water vapor introduction part, permeates and evaporates it, and supplies it to the sorbent / desorbent substantially uniformly. It is a sorption / desorption tank characterized by being a water vapor transmission means.

In the above sorption / desorption tank,
There is a space between the sorption / desorption agent and the water vapor transmission means,
The water vapor that has permeated and evaporated through the water vapor transmission means is supplied to the sorbent / desorbent substantially uniformly through the space, and the water desorbed from the sorbent / desorbent moves from the space to the outside. It is a sorption / desorption tank characterized by.

<Heat storage tank>
In addition, it is effective if the following heat storage tank is applied to the latent heat storage system.

A heat storage tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A heat storage agent that contains water, the water storage agent that evaporates and condenses, water vapor transmission means that transmits and evaporates only water from the cold storage agent to the outside, and heat exchange that exchanges heat during the evaporation with heat from the outside. And a heat exchange means for condensing the water vapor from the outside and circulating it to the cool storage agent, and exchanging the heat at the time of the condensation with the outside heat.

A heat storage tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A regenerator stored in the heat storage tank, containing water, and evaporating and condensing the water;
A heat exchanging means immersed in the cold storage agent and exchanging heat at the time of evaporation with external heat;
Heat exchange that is arranged in a space where the cool storage agent is not stored inside the heat storage tank, condenses the water vapor from the outside, circulates to the cool storage agent, and exchanges heat during the condensation with external heat Means,
Having one or more water vapor transmission tubes immersed in the cold storage agent,
The water vapor transmission pipe is a water vapor transmission means for allowing the outside of the pipe to face the cold storage agent and the inside of the pipe to communicate with the outside, and allowing only water from the cold storage agent outside the pipe to pass through and evaporate into the pipe. A heat storage tank characterized by being.

In the above heat storage tank,
The said cool storage agent contains an emulsion, The heat storage tank characterized by the above-mentioned.

According to the latent heat storage system according to the present invention,
(1) By installing a water vapor transmission means that allows only moisture (latent heat medium) to pass through in the sorption / desorption tank, moisture diffusion can be performed almost uniformly on the sorption / desorption agent. As a result, the volume utilization efficiency of the sorption / desorption agent can be improved.

(2) By applying the “sorption / desorption agent” instead of the “adsorption / desorption agent”, the operation in a very low temperature range of about 30 ° C. to 100 ° C. is possible. As a result, it is possible to effectively use low-level waste heat such as a distributed power source (fuel cell, etc.), factory waste heat (incinerator, etc.), household waste heat (hot waste water, etc.), and hot springs.

(3) A heat storage density can be improved by mixing emulsion (for example, microcapsule) in the cool storage agent of a heat storage tank. As a result, the heat storage tank can be scaled down.

(4) By disposing the water vapor transmission means in the heat storage tank, only moisture can be transferred from the heat storage tank to the sorption / desorption tank as a latent heat medium, and components other than water contained in the cool storage agent leak from the heat storage tank. In addition to preventing this, the latent heat of vaporization of water can be effectively transferred to the cold storage agent. As a result, the heat storage tank can be scaled down.

  The low temperature region matches the waste heat temperature level of solid polymer fuel cells and the like that are expected to spread in the future, and is used as a heat source for driving a heat pump or as a heat storage source. -Heat can be used as a heat storage tank for heating, drying, or nighttime.

  Further, for business use and industrial use, low-temperature steam of about 100 ° C., low-temperature drain, or low-temperature exhaust gas, which has heretofore had little utility value, can be widely used as a heat process heat source.

<Latent heat storage system / Latent heat storage method>
Hereinafter, although an embodiment of the present invention is described in detail using a drawing, the present invention is not limited to this. FIG. 1 is a schematic configuration diagram of a latent heat storage system according to an embodiment of the present invention.

  As shown in FIG. 1, the latent heat storage system 10 according to the present embodiment includes a sorption / desorption tank 11, a heat storage tank 18, a steam pipe 26 connecting both tanks 11, 18, and a selection for controlling a steam flow path. It consists of valves 27a and 27b.

  The sorption / desorption tank 11 is filled inside, and a sorption / desorption agent 12 that sorbs and desorbs water vapor, and a heat exchanger 14 that exchanges heat between the heat of the sorption / desorption agent 12 and heat from outside the system 10, The water supply section 15 is a space for supplying water vapor from the heat storage tank 18 to the inside of the sorption / desorption tank 11, and is a space that is in contact with the sorption / desorption agent 12 and supplies water vapor generated from the sorption / desorption agent 12 to the heat storage tank 18. It comprises an evaporation section 16 and a water vapor transmission means 13 provided between the water vapor introduction section 15 and the evaporation section 16.

  The water vapor transmission means 13 includes a water vapor transmission film part 13b on the water vapor introduction part 15 side and a base material part 13a on the evaporation part 16 side, and the water vapor transmission film part 13b is a thin film made of silica having a thickness of about 5 to 10 μm. The base material portion 13a is a ceramic base material having a thickness of about 1 mm.

  The sorptive / desorbent is a polymer fine particle provided with a moisture absorption and desorption function on the polymer skeleton, and has a moisture absorption / desorption rate that is 2 to 3 times that of a conventional “adsorption / desorption agent” represented by silica gel. In addition, the conventional adsorption / desorption agent is crushed and pulverized by repeated moisture absorption and desorption operations, whereas the sorption / desorption agent is not crushed and has excellent repetition characteristics.

  Under the control of the selection valve 27a, the steam pipe 26 is connected to the steam introduction section 15 or the evaporation section 16, and, as will be described in detail below, the steam pipe 26 is circulated from the heat storage tank 18 in the sorption process. The water vapor thus circulates in the water vapor introduction part 15, and in the desorption process, the water vapor desorbed and evaporated from the adsorption / desorption agent 12 to the evaporation part 16 flows through the water vapor pipe 26 toward the heat storage tank 18.

  The heat storage tank 18 is stored in the heat storage tank 18, and performs heat exchange between the cold storage agent 19 made of water, a freezing point depressant (antifreeze), and an emulsion, and heat exchange between the heat of the cold storage agent 19 and the heat from the outside of the system 10. A regenerator 21, a water vapor transmission means 20 that evaporates and permeates only moisture in the regenerator 19, an evaporation unit 23 that is a space for supplying permeated water vapor to the sorption / desorption tank 11, and a regenerator 19 in the heat storage tank 18. The heat exchanger 22 is installed in a non-reserved space and performs heat exchange between the latent heat of the water vapor from the sorption / desorption tank 11 and the heat from the outside of the system 10, and condenses the water vapor and circulates it to the cool storage agent 19. And the condensing part 24 which is the space to be condensed.

  The water vapor transmission means 20 includes a water vapor transmission film part 20b on the cold storage agent 19 side and a base material part 20a on the evaporation part 23 side, and the water vapor transmission film part 20b is a thin film made of silica having a thickness of about 5 to 10 μm. Yes, the base material portion 20a is a ceramic base material having a thickness of about 1 mm.

  The freezing point depressant (antifreeze) constituting the regenerator 19 is for preventing freezing of the regenerator 19 in the sorption process (evaporation of water from the regenerator 19) described in detail below. This is to improve the heat storage density of the cold storage agent 19 by utilizing the solid-liquid phase change.

  Under the control of the selection valve 27b, the water vapor pipe 26 is connected to the evaporation unit 23 or the condensation unit 24. As described in detail below, the vapor pipe 26 has evaporated from the cold storage agent 19 to the evaporation unit 23 in the sorption process. The water vapor flows through the water vapor pipe 26 toward the sorption / desorption tank 11, and the water vapor flowing through the water vapor pipe 26 from the sorption / desorption tank 11 flows through the condensing unit 24 in the desorption process.

<Sorption process in this system and method>
FIG. 2 is a diagram illustrating a sorption process in the latent heat storage system according to the embodiment of the present invention. In the sorption process, the selection valve 27a is opened to the water vapor introduction unit 15 side, and the selection valve 27b is opened to the evaporation unit 23 side.

  By making the inside of the system consisting of the evaporation section 23, the steam pipe 26, the steam introduction section 15 and the evaporation section 16 into a negative pressure state (about 30 torr) by the vacuum pump 30, the water content in the regenerator 19 through the steam transmission means 20. Only vapor is allowed to evaporate and permeate through the evaporating section 23 (selective evaporation 1 only with moisture).

  The generated water vapor is controlled by the selection valve 27b to flow through the water vapor pipe 26 toward the sorption / desorption tank 11 (water vapor 2 flowing through the pipe), and is controlled by the selection valve 27a to flow into the water vapor introduction section 15.

  The water vapor flowing into the water vapor introducing section 15 is uniformly condensed on the surface of the water vapor permeable film section 13b in the water vapor permeable means 13 (uniform condensation 3) and then evaporated again when passing through the water vapor permeable means 13 to form water vapor ( Evaporation 4) and flows into the evaporation section 16. As a result, it is possible to supply water vapor without any spots on the surface of the sorbent / desorbent 12 in the evaporation section 16.

  When water vapor is directly introduced from the water vapor pipe 26 to the evaporation unit 16 without passing through the water vapor transmission means 13, a large amount of water vapor is supplied to the sorbent / desorption agent in the vicinity of the introduction port to the evaporation unit. Further, there is a risk that it is difficult to supply water vapor to the sorbent / desorbent.

  On the other hand, by introducing into the evaporation part 16 through the water vapor transmission means 13 as in the present embodiment, it becomes possible to diffuse and supply water vapor without any spots through the uniform condensation 3 and the re-evaporation 4. ing. Moreover, it is possible by this effect | action to reduce the water | moisture-content spreading | diffusion resistance of the filled sorbent / desorbent 12. FIG.

  Note that the balance of heat generated during the condensation 3 and the re-evaporation 4 of the water vapor in the water vapor transmission means 13 is completed in the water vapor transmission means 13.

  Finally, the water vapor uniformly supplied to the sorbent / desorbent 12 is uniformly sorbed on the sorbent / desorbent 12 (uniform sorption 5).

In the sorption process described above, when the moisture in the regenerator 19 evaporates and permeates through the water vapor permeation means 20 to the evaporation unit 23 (selective evaporation 1 of only water), the latent heat of vaporization of water is immersed in the regenerator 19. It collect | recovers with the made heat exchanger 21, and uses as a cold-heat source. That is, the medium V ₁ from the outside is cooled by latent heat of vaporization and used as the medium V ₂ after passing through a relatively low-temperature heat exchanger.

Further, when water vapor uniformly supplied to the sorbent / desorbent 12 sorbs on the sorbent / desorbent 12 (uniform sorption 5), the sorption heat generated from the sorbent / desorbent 12 contacts the sorbent / desorbent 12. It collect | recovers with the made heat exchanger 14, and uses as a heat source. That is, the medium V ₃ from the outside is heated by sorption heat and used as the medium V ₄ after passing through a relatively high temperature heat exchanger.

<Desorption process in the present system and method>
FIG. 3 is a diagram illustrating a desorption process in the latent heat storage system according to the embodiment of the present invention. In the desorption process, the selection valve 27a is opened on the evaporation unit 16 side, and the selection valve 27b is opened on the condensation unit 24 side.

  The inside of the system consisting of the evaporation section 16, the steam pipe 26 and the condensation section 24 is brought into a negative pressure state (about 30 torr) by the vacuum pump 30, and the sorbent / desorbent 12 is removed by the heat exchanger 14 brought into contact with the sorbent / desorbent 12. By heating, moisture adsorbed on the sorbent / desorbent 12 is desorbed / evaporated (desorption / evaporation 6).

  The water vapor generated by desorption / evaporation is controlled by the selection valve 27a to flow through the water vapor pipe 26 toward the heat storage tank 18 (water vapor 7 flowing through the pipe), and is controlled by the selection valve 27b to flow into the condensing unit 24. .

  Finally, the water vapor flowing into the condensing unit 24 is cooled and condensed (cooled / condensed 8) by the heat exchanger 22 installed in the space where the regenerator 19 inside the heat storage tank 18 is not stored, and becomes moisture. It is collected in the cold storage agent 19.

In the above desorption process, moisture desorption / evaporation latent heat is supplied by the heat exchanger 14 in contact with the sorption / desorption agent 12, and the sorption / desorption agent 12 is heated by the heat exchanger 14 to be collected in the sorption / desorption agent 12. Desorbed / evaporated (desorbed / evaporated 6) the water that is being worn. That is, the medium V ₅ from the outside passing through the heat exchanger 14 is cooled by the desorption / evaporation latent heat, and discharged as a medium V ₆ after passing through the heat exchanger having a relatively low temperature. Thereby, unused thermal energy can be recovered.

Further, when the water vapor flowing into the condensing unit 24 is cooled / condensed (cooling / condensation 8) by the heat exchanger 22, the heat of condensation is recovered by the heat exchanger 22 and used as a heat source. That is, the medium V ₇ from the outside is heated by the condensation heat and used as the medium V ₈ after passing through a relatively high-temperature heat exchanger.

  In the basic cycle consisting of the above sorption process and desorption process, by combining the sorption / desorption agent 12 having excellent sorption / desorption characteristics and the water vapor permeation means 13 and 20 that transmit only moisture from the cold storage agent 19, high efficiency and compactness are achieved. The latent heat storage system 10 can be obtained.

  Further, by providing the water vapor transmission means 20, it is possible to prevent the freezing point depressant (antifreeze) and emulsion from entering the water vapor pipe 26, and by providing the water vapor transmission means 13, it is included in the cold storage agent 19. It is possible to prevent the freezing point depressant (antifreeze) and emulsion from being mixed into the sorption / desorption agent 12.

<Example of specific structure of sorption / desorption tank>
FIG. 4 is a partial schematic external view (a) of a sorption / desorption tank of the latent heat storage system according to the embodiment of the present invention, a diagram (b) for explaining a sorption process in an A-direction arrow section, and an A-direction arrow view. It is a figure (c) explaining the desorption process in a cross section.

  In the sorption / desorption tank 11 according to this embodiment, as shown in FIG. 4, a plurality of sorption / desorption tubes 11 ′ (one sorption / desorption tube is shown in FIG. 4) are arranged in the space of the water vapor introduction section 15. It becomes. The sorption / desorption tube 11 ′ has a double tube structure including an outer tube and an inner tube, the outer tube is a water vapor introduction portion 15, and the inner tube is a medium flow path of the heat exchanger 14. A space for the evaporation portion 16 is formed between the outer tube and the inner tube.

  The outer tube is a water vapor transmission means 13 including a base material portion 13a constituting an inner portion of the outer tube and a water vapor permeable film portion 13b constituting the outer portion of the outer tube. The inner tube is an inner portion of the inner tube. The heat exchanger 14 that constitutes and the sorbent / desorbent 12 that constitutes the outer part of the inner tube.

  The sorption process in the sorption / desorption tank 11 according to the present embodiment is as described with reference to FIG. 2, and will be further described with reference to the cross-sectional structure diagram of the sorption / desorption tube shown in FIG.

  After the water vapor introduced into the water vapor introducing part 15 which is a space for accommodating the sorption / desorption pipe 11 ′ is uniformly condensed (uniform condensation 3) on the surface of the water vapor permeable film part 13b in the water vapor permeable means 13 which is the outer pipe, When passing through the water vapor transmission means 13, it evaporates again to become water vapor (evaporation 4) and flows uniformly into the evaporation section 16.

The water vapor that has flowed into the evaporation section 16 is uniformly supplied to the sorbent / desorbent 12 constituting the outer portion of the inner tube, and is uniformly sorbed onto the sorbent / desorbent 12 (uniform sorption 5). At this time, the sorption heat generated from the sorbent / desorbent 12 is contacted with the sorbent / desorbent 12 and recovered by the heat exchanger 14 constituting the inner portion of the inner tube and used as a heat source. That is, the medium V ₃ from the outside is heated by sorption heat by passing through the medium flow path of the heat exchanger 14, and is used as the medium V ₄ after passing through the relatively high temperature heat exchanger. .

  The desorption process in the sorption / desorption tank 11 according to the present embodiment is as described with reference to FIG. 3, and will be further described with reference to the cross-sectional structure diagram of the sorption / desorption tube shown in FIG.

The inside of the system such as the evaporation section 16 is brought into a negative pressure state (about 30 torr), and the sorbent / desorbent 12 constituting the outside of the inner pipe is heated by the heat exchanger 14 constituting the inside of the inner pipe, thereby sorption / desorption. The water sorbed on the agent 12 is desorbed and evaporated (desorption / evaporation 6). Thereby, the effective utilization (recovery) of the waste heat utilized as a heat source can be performed. That is, the medium V ₅ from the outside passes through the medium flow path of the heat exchanger 14, is cooled by the desorption / evaporation latent heat, and is used as the medium V ₆ after passing through the relatively low-temperature heat exchanger. The

<Example of specific structure of heat storage tank>
FIG. 5: is a partial schematic external view (a) of the heat storage tank of the latent heat storage system which concerns on embodiment of this invention, and the figure (b) explaining the sorption process in a B direction arrow cross section.

  As shown in FIG. 5, the heat storage tank 18 according to the present embodiment includes a plurality of water vapor transmission pipes 18 ′ as water vapor transmission means in the cold storage agent 19 (FIG. 5 shows one water vapor transmission pipe). Furthermore, the heat exchanger 21 is arrange | positioned and the heat exchanger 22 (not shown) is arrange | positioned in the space where the cool storage agent 19 in the heat storage tank 18 is not stored.

  The water vapor transmission pipe 18 ′ has a single pipe structure, the cold storage agent 19 on the outside of the pipe, and the evaporation part 23 on the inside of the pipe. The base material portion 20a constituting the inner portion of the pipe, and the outer portion of the pipe And a water vapor permeable membrane portion 20b.

  The sorption process in the heat storage tank 18 according to the present embodiment is as described with reference to FIG. 2, and will be further described with reference to the cross-sectional structure diagram of the water vapor transmission pipe shown in FIG.

  By setting the inside of the system such as the evaporation unit 23 to a negative pressure state (about 30 torr), only the water in the cool storage agent 19 is evaporated and permeated to the evaporation unit 23 via the water vapor transmission pipe 18 ′ (selective evaporation 1 only of water). ). At this time, the latent heat of vaporization of water is collected by a heat exchanger 21 immersed in the cold storage agent 19 and used as a cold heat source.

That is, the cool storage agent 19 is cooled by the evaporation of water, and the cooling heat is transmitted to the heat exchanger 21 (generation and movement 9 of cold heat due to water evaporation), and the medium V ₁ from the outside is the medium of the heat exchanger 21. By passing through the flow path, it is cooled by latent heat of vaporization and used as a medium V ₂ after passing through a relatively low-temperature heat exchanger.

<Effects of the latent heat storage system and the latent heat storage method according to this embodiment>
In order to recover and utilize low-level waste heat such as distributed power sources, a compact latent heat storage system that operates at 100 ° C. or lower is necessary. Conventionally, as a system that operates in an operating region exceeding 100 ° C., research and development of a latent heat storage system using an “adsorption / desorption agent” such as silica gel has been actively conducted with the aim of hot water supply, heating, cooling, or drying. It was. However, the heat storage density is low and the heat storage tank is not sufficiently miniaturized, and the adsorption / desorption agent may be deteriorated or damaged due to repeated adsorption / desorption, and it has not been widely used.

  In this embodiment, by adopting an organic “absorption / desorption agent” instead of the “adsorption / desorption agent” as the heat storage agent, it is possible to reduce the size of the system and improve the durability of the heat storage agent. That is, the mass absorption / desorption amount of the organic sorbent / desorbent is as large as 2 to 3 times that of the conventional silica gel or the like, so that the size can be greatly reduced as compared with the conventional heat storage system.

  In addition, since the operating temperature (sorption / desorption temperature) of the sorbent / desorbent is as low as about 30 ° C to 100 ° C, it can be applied as the final stage of the thermal cascade of small to medium-sized distributed cogeneration systems for general household use. It becomes. It can be used in a wide range of fields such as cooling / heating, night heat storage, hot water supply, drying, dehumidification.

  Furthermore, by applying the water vapor transmission means, it is possible to make the medium supply to the sorbent / desorbent uniform, increase the heat and the moving speed of the medium, improve the volume utilization rate of the filled sorbent / desorbent, and further reduce the size. Is possible. For example, compared with a heat storage system using silica gel, a reduction of about 50% is expected.

<Necessity of heat / mass transfer speed improvement in latent heat storage system and latent heat storage method>
In the utilization of a latent heat storage system, how quickly heat and material can be taken in and out is an important matter, and this becomes a coupled problem of complicated heat and mass transfer phenomenon. Increasing the latent heat transfer rate in the sorption-desorption phenomenon of the sorbent / desorbent has the problem that when the sorbent / desorbent is used as a packed bed, the thermal conductivity and the resistance to material diffusion increase, resulting in an increase in the size of the system. .

  In order to solve this problem, a water vapor permeation means is introduced into the sorption / desorption tank, so that heat and mass transfer speed can be increased and uniform dispersion can be achieved. As a result, in the sorption step, it is possible to increase the amount of moisture sorbed per hour on the sorbent / desorbent by reducing the diffusion resistance and increasing the specific surface area. In the desorption process, the heat of the waste heat source is quickly transmitted to the desorption agent, so that the desorption time can be shortened and the size can be reduced. Such rapid heat and mass transfer can increase the heat transfer speed equivalent to or higher than that of a conventional compression heat pump system.

<Increase of latent heat storage density and prevention of deterioration>
Water is used for the working medium of the latent heat storage system according to the present embodiment. In order to improve the heat transfer speed during heat storage recovery, the water in the heat storage tank maintains a supercooled liquid phase by adding a freezing point depressant (antifreeze). For this reason, in order to increase the heat storage density, an emulsion in which the vicinity of the water freezing point becomes the freezing point is contained to improve the heat storage density.

  The operating environment of the latent heat storage system according to the present embodiment is pure water vapor (single component) as a working medium and a vacuum atmosphere. Therefore, when components other than moisture are mixed in the working medium, it adversely affects the deterioration of the sorbent / desorbent and the condensation heat transfer. Therefore, deterioration of the heat storage density can be prevented by using a water vapor transmission means that transmits only moisture.

<Use of latent heat storage system and latent heat storage method according to this embodiment>
The latent heat storage system using the sorption / desorption agent and water vapor transmission means according to the present embodiment is a low temperature region where the sorption / desorption temperature of the sorption / desorption agent ranges from about 30 ° C. to 100 ° C. It is a great advantage that the waste heat that has been used can be used. There are sufficient potential needs for the utilization of unused waste heat in the low temperature region in the consumer and industrial fields. For example, the following applications are conceivable.

  That is, for example, the use of cascades with small distributed power sources (solid polymer fuel cells, etc.) that will become more widespread in the future includes air conditioning (cooling and heating, dehumidification), nighttime heat storage, hot water supply, etc. for residential buildings, buildings, hospitals, etc. It is done. In addition, industrial applications include air conditioning in factories and offices, refrigeration, drying, and feedback of waste heat to the process. Furthermore, it can be expected to be used as a large-scale air-conditioning facility that uses the waste heat of cogeneration for district heating and cooling.

  In the above-described embodiment, as shown in FIG. 4, the sorption / desorption tube 11 ′ is disposed in the space of the introduction portion 15 in the outer tube, the heat exchanger 14, and the sorption / desorption agent 12. Although a plurality of sorption / desorption tubes 11 ′ composed of tubes are arranged in the space of the water vapor introducing portion 15, the functions of the outer tube and the inner tube are reversed, and the inside of the inner tube is connected to the water vapor introducing portion. In addition, the outside of the outer tube may be used as a heat circulation part from the outside.

  That is, one or a plurality of sorption / desorption tubes are provided in a portion through which heat from the outside flows, and the sorption / desorption tube includes an inner portion constituted by a sorption / desorption agent for sorption / desorption of water, As an outer pipe composed of an outer portion constituted by a heat exchanger that exchanges heat with external heat, and a water vapor introduction section for introducing water vapor from the outside into the pipe, the water vapor introduced into the water vapor introduction section is condensed. Further, it may be a double pipe structure comprising an inner pipe which is a water vapor permeation means which is permeated and evaporated and then supplied substantially uniformly to the sorbent / desorbent.

1 is a schematic configuration diagram of a latent heat storage system according to an embodiment of the present invention. It is a figure explaining the sorption process in the latent heat storage system which concerns on embodiment of this invention. It is a figure explaining the desorption process in the latent-heat thermal storage system which concerns on embodiment of this invention. The partial schematic external view (a) of the sorption / desorption tank of the latent heat storage system which concerns on embodiment of this invention, the figure (b) explaining the sorption process in an A direction arrow cross section, and the desorption process in an A direction arrow cross section FIG. It is the figure (b) explaining the sorption process in the partial schematic external view (a) of the thermal storage tank of the latent-heat thermal storage system which concerns on embodiment of this invention, and a B direction arrow cross section.

Explanation of symbols

1 Selective evaporation of moisture only 2 Water vapor flowing through piping 3 Uniform condensation 4 Evaporation 5 Uniform sorption

6 Desorption / evaporation 7 Water vapor flowing through the pipe 8 Condensation 9 Generation and movement of cold due to water evaporation

V ₁ , V ₃ , V ₅ , V ₇ External media
Medium after passing through V ₂ , V ₄ , V ₆ , V ₈ heat exchanger

DESCRIPTION OF SYMBOLS 10 Latent heat storage system 11 Sorption / desorption tank 11 'Sorption / desorption pipe | tube 12 Sorption / desorption agent 13 Water vapor permeation means (1st water vapor permeation means)
13a Base part 13b Water vapor permeable membrane part 14 Heat exchanger (first heat exchange means)
15 Water vapor introduction part 16 Evaporation part

18 Heat storage tank 18 'Water vapor transmission pipe 19 Cold storage agent 20 Water vapor transmission means (second water vapor transmission means)
20a base material part 20b water vapor permeable membrane part 21 heat exchanger (second heat exchange means)
22 Heat exchanger (third heat exchange means)
23 Evaporating section 24 Condensing section

26 Steam piping 27a Selection valve 27b Selection valve 30 Vacuum pump

Claims (14)

A latent heat storage system having a sorption / desorption tank and a heat storage tank,
The sorption / desorption tank condenses water vapor from the heat storage tank, a sorption / desorption agent for sorption and desorption of water, first heat exchange means for exchanging heat at the time of sorption or desorption with external heat, and the like. A first water vapor permeation means that permeates and evaporates and then supplies the sorbent / desorbent substantially uniformly.
The heat storage tank contains water, a cold storage agent that evaporates and condenses the water, second heat exchange means that exchanges heat during the evaporation with external heat, and condenses water vapor from the sorbent / desorbent. And a third heat exchanging means for exchanging the heat during the condensation with the external heat and circulating to the cold storage agent. In the latent heat storage system according to claim 1,
The said heat storage tank has a 2nd water vapor permeation | transmission means which permeate | transmits and evaporates only water from the said cool storage agent, The latent heat storage system characterized by the above-mentioned. In the latent heat storage system according to claim 1 or 2,
Having a space between the sorption / desorption agent and the first water vapor transmission means;
The water vapor that has permeated and evaporated through the first water vapor transmission means is substantially uniformly supplied to the sorbent / desorbent via the space, and water desorbed from the sorbent / desorbent is supplied from the space to the heat storage tank. A latent heat storage system characterized by moving. In the latent heat storage system according to any one of claims 1 to 3,
The said cool storage agent contains emulsion, The latent heat storage system characterized by the above-mentioned. A latent heat storage method for performing a sorption process and a desorption process using a sorption / desorption tank and a heat storage tank,
The sorption step evaporates water from a regenerator containing water in the heat storage tank, exchanges heat at the time of the evaporation with external heat, and transmits water vapor from the heat storage tank to the first water vapor. Latent heat, characterized in that it is substantially uniformly sorbed to the sorbent / desorbent in the sorption / desorption tank by being permeated / evaporated after being condensed by means, and exchanging the heat during the sorption with external heat. Thermal storage method. In the latent heat storage method according to claim 5,
In the desorption step, water is desorbed from the sorption / desorption agent in the sorption / desorption tank, the heat during the desorption is exchanged with external heat, and water vapor from the sorption / desorption tank is condensed, A latent heat storage method characterized by circulating to a cool storage agent in a heat storage tank and exchanging heat at the time of condensation with external heat. In the latent heat storage method according to claim 5 or 6,
A latent heat storage method, wherein only water is transmitted and evaporated by the second water vapor transmission means when water is evaporated from the cold storage agent in the sorption step. In the latent heat storage method according to any one of claims 5 to 7,
Having a space between the sorption / desorption agent and the first water vapor transmission means;
The water vapor that has permeated and evaporated through the first water vapor transmission means is substantially uniformly supplied to the sorbent / desorbent via the space, and water desorbed from the sorbent / desorbent is supplied from the space to the heat storage tank. The latent heat storage method characterized by moving. In the latent heat storage method according to any one of claims 5 to 8,
The said cool storage agent contains an emulsion, The latent heat storage method characterized by the above-mentioned. A sorption / desorption tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A sorption / desorption agent for sorption and desorption of water, the heat exchange means for exchanging heat at the time of sorption or desorption with external heat, and permeating and evaporating after condensing water vapor from the outside A sorption / desorption tank comprising water vapor transmission means for supplying the sorbent / desorbent substantially uniformly. In the sorption / desorption tank according to claim 10,
There is a space between the sorption / desorption agent and the water vapor transmission means,
The water vapor that has permeated and evaporated through the water vapor transmission means is supplied to the sorbent / desorbent substantially uniformly through the space, and the water desorbed from the sorbent / desorbent moves from the space to the outside. A sorption / desorption tank. A sorption / desorption tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A water vapor introduction part for introducing water vapor from the outside, and one or a plurality of sorption / desorption tubes provided in the water vapor introduction part,
The sorption / desorption tube has a double-pipe structure composed of an inner tube and an outer tube,
The inner pipe is constituted by an outer part constituted by a sorption / desorption agent for sorption and desorption of water, and an inner part constituted by the heat exchange means for exchanging heat at the time of the sorption or desorption with external heat. And consist of
The outer tube is a water vapor permeable / desorption tank characterized in that the water vapor introduced into the water vapor introducing part is condensed and permeated / vaporized, and is supplied to the sorbent / desorbent substantially uniformly. A sorption / desorption tank that exchanges water vapor with the outside and exchanges heat with external heat by means of heat exchange provided inside,
A portion through which heat from the outside flows, and one or a plurality of sorption / desorption tubes provided in the portion through which the heat flows,
The sorption / desorption tube has a double-pipe structure composed of an inner tube and an outer tube,
The outer tube includes an inner part constituted by a sorption / desorption agent that sorbs and desorbs water, and an outer part constituted by the heat exchange means that exchanges heat at the time of sorption or desorption with external heat. And consist of
The inner pipe is a water vapor introduction part that introduces water vapor from the outside into the pipe, condenses the water vapor introduced into the water vapor introduction part, permeates and evaporates it, and supplies it to the sorbent / desorbent substantially uniformly. A sorption / desorption tank characterized by being a water vapor transmission means. In the sorption / desorption tank according to claim 12 or 13,
There is a space between the sorption / desorption agent and the water vapor transmission means,
The water vapor that has permeated and evaporated through the water vapor transmission means is supplied to the sorbent / desorbent substantially uniformly through the space, and the water desorbed from the sorbent / desorbent moves from the space to the outside. A sorption / desorption tank.

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