JP2010230268A - Chemical heat pump device and method of using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a constitution by dispensing with a pressure reducing pump and the like, and to easily perform maintenance without resupplying the water. <P>SOLUTION: This chemical heat pump device includes a reaction container 1 receiving a heat storage material generating heat by chemical reaction with at least the water and absorbing heat by dehydration reaction, a first flow channel 10 for allowing the water of liquid stored in a condensation container 2 to circulate toward the reaction container 1 in a heat generating process, and a second flow channel 20 for allowing the vapor generated in the reaction container 1 to circulate toward the condensation container in a heat absorbing process. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chemical heat pump device using heat generation and heat absorption by a chemical reaction and a method of using the chemical heat pump device.

  For example, in JP-A-59-180258, two sealed tanks are connected by one connecting pipe provided with a valve, a heat storage material made of calcium chloride is put in one tank, and water is put in the other tank. A chemical heat pump device is described in which the entire system is degassed. This chemical heat pump device utilizes heat generation due to a chemical reaction between calcium chloride and water and heat absorption due to a dehydration reaction.

  In this chemical heat pump device, there is no gas other than water vapor inside, an exothermic reaction occurs when the water vapor is supplied to the heat storage material through the connecting pipe, and the water vapor generated by the endothermic reaction is connected by heating the heat storage material. Return to the other tank through the tube. However, the exothermic heat generated by the chemical reaction using water vapor has a problem that the reaction rate is extremely slow and the calorific value per unit time is small.

  Thus, for example, Japanese Patent Application Laid-Open No. 2004-003832 proposes a chemical heat storage device that utilizes heat generation due to the reaction between calcium chloride and water and heat absorption due to a dehydration reaction. The publication describes that liquid water is supplied to a heat storage material housed in a reaction vessel, and engine cooling water is heated using heat generated by a chemical reaction of the heat storage material. By doing in this way, a chemical reaction rate becomes large and the emitted-heat amount per unit time improves.

  The publication also describes that the inside of the reaction vessel is decompressed by heating the heat storage material and discharging the water vapor generated by the dehydration reaction to the outside. By doing in this way, dehydration of the heat storage material can be performed efficiently in a short time, and the heat storage state of the heat storage material can be well maintained even if left for a long time.

JP 59-180258 JP 2004-003832 A

  However, in the chemical heat storage device described in Patent Document 2, water vapor generated by a dehydration reaction is discharged to the outside during heat storage by heat absorption. Since this water vapor was originally dehydrated water that reacted with the heat storage material, it was necessary to periodically supplement the deficient water that was discharged in order to generate heat next time. In addition, a decompression pump for discharging water vapor is necessary at the time of use, and there is a problem that the apparatus becomes large.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to simplify the configuration without using a vacuum pump or the like, and facilitate maintenance without supplying water.

  The characteristics of the chemical heat pump device of the present invention that solves the above-described problems are characterized in that a condensation container, a reaction container containing a heat storage material that generates heat by a chemical reaction between at least a water-containing liquid and absorbs heat by a dehydration reaction, and is stored in the condensation container. A first flow path through which at least water-containing liquid flows toward the reaction container; supply means for supplying at least water-containing liquid stored in the condensation container to the reaction container through the first flow path; and generated in the reaction container And the second flow path in which the gas containing at least water vapor flows toward the condensing container.

  In addition, the method of using the chemical heat pump of the present invention is characterized in that the chemical heat pump apparatus of the present invention is used, the first flow path is opened, a liquid containing at least water is supplied to the heat storage material by the supply means, and the heat medium generates heat by the chemical reaction. And an endothermic process in which the second flow path is opened and a gas containing at least water vapor generated by a dehydration reaction by heat from the heat medium is condensed and stored in a condensation container.

  According to the chemical heat pump device of the present invention and the method of using the chemical heat pump device, the heat storage material generates heat by a chemical reaction with the liquid containing at least water by supplying a liquid containing at least water to the heat storage material. The engine cooling water or the like can be heated using this heat generation, and the engine can be warmed up or the passenger compartment can be heated. Further, in a state where the engine cooling water or the like is sufficiently heated, a gas containing at least water vapor is generated from the heat storage material by the dehydration reaction, and part or all of this gas is condensed and stored as a liquid in the condensation container. Therefore, it is not necessary to replenish at least a liquid containing water from the outside, and it operates in a closed system, so that maintenance is easy.

It is explanatory drawing which shows the action | operation of the heat_generation | fever process in the chemical heat pump apparatus of this invention. It is explanatory drawing which shows the operation | movement of the endothermic process in the chemical heat pump apparatus of this invention. It is a block diagram of the chemical heat pump apparatus which concerns on one Example of this invention. It is a block diagram of the chemical heat pump apparatus which concerns on the 2nd Example of this invention. It is sectional drawing of the reaction container used for the chemical heat pump apparatus which concerns on the 2nd Example of this invention. It is a block diagram of the chemical heat pump apparatus which concerns on the 3rd Example of this invention.

  The operation mechanism of the chemical heat pump apparatus according to the present invention will be described with reference to FIGS. 1 and 2. First, in the exothermic process shown in FIG. 1, a liquid containing at least water stored in the condensing container is supplied to the reaction container through the first flow path. Then, since the heat storage material in the reaction vessel reacts with at least water and generates heat, the heat energy generated by the heat generation can be taken out from the reaction vessel.

  In the endothermic process shown in FIG. 2, at least the heat storage material that has reacted with water in the reaction vessel is heated by heat energy supplied from the outside. Then, a gas containing water vapor is desorbed from the heat storage material by the dehydration reaction, heads for the second passage, and part or all of it is condensed and stored in the condensation container. On the other hand, the heat storage material becomes a heat storage state by dehydration and prepares for the next heat generation process.

The heat storage material used in the chemical heat pump device of the present invention is one that generates heat at least by a chemical reaction with water and absorbs heat by a dehydration reaction, such as calcium chloride (CaCl ₂ ), calcium oxide (CaO), magnesium oxide (MgO), Examples thereof include composite oxides of Mg and a metal selected from Ni, Co, Cu and Al, calcium bromide (CaBr ₂ ), lithium bromide (LiBr), calcium sulfate (CaSO ₄ ) and the like. Of these, calcium chloride or the like generates heat when dissolved in water or alcohol, and calcium oxide or the like generates heat when it becomes a hydroxide. In addition, calcium sulfate generates heat during the hydration reaction.

  A heat storage material is stored in the reaction container, and a liquid containing at least water stored in the condensation container is supplied from the first flow path to the heat storage material. For example, when calcium chloride is used as the heat storage material, at least the chemical reaction with water proceeds rapidly, so it is desirable that the amount of liquid corresponding to the amount of the heat storage material and the heat storage material are brought into contact as quickly as possible. By doing so, large heat energy is generated at once.

  In order to do this, it is desirable to increase the surface area as a droplet by discharging a liquid containing at least water in a shower form. In order to increase the contact area between the heat storage material and the liquid containing at least water, it is desirable that the heat storage material is powdery and is stored in the reaction vessel so that the surface of each particle is exposed as much as possible.

  In the endothermic process, the heat storage material may be in the form of a cake. In such a case, in the deep heat storage material, the gas generated by the dehydration reaction is difficult to escape and the efficiency decreases. Therefore, it is desirable that the heat storage material has a structure in which gas can easily escape even if it is cake-like.

  In order to store in the reaction vessel so that the surface of the heat storage material particles is exposed as much as possible, it is preferable to dispose a porous material in the reaction vessel and attach the heat storage material powder to the surface. As the porous material, those having continuous pores are desirable. The continuous pores serve as a passage for a liquid containing at least water, and the gas generated during the dehydration reaction also serves as a passage toward the second flow path. Various materials can be used as the porous material, but in order to efficiently recover the generated thermal energy, it is desirable that it has excellent thermal conductivity, and it is a collection of metal fiber aggregates, punching metal, and metal ribbons. It is desirable to use a body, a foam metal or the like.

  According to the experiments by the inventors of the present application, as an example of an assembly of metal ribbons, stainless steel scrubbing for household use and a heat storage material (reacted with calcium chloride and water) placed in a container; What was not added was heated to 200 ° C in the air at the same time. About 50% of the water was dehydrated when there was no stainless scrubbing, but more than 80% of the water was dehydrated when stainless steel was present. It has been confirmed that. That is, the coexistence of a porous material having continuous pores can greatly reduce the time required for the dehydration reaction.

  For example, calcium chloride as a heat storage material reacts chemically with liquid water and generates heat. Moreover, although calorific value when calcium chloride absorbs methanol is smaller than that of water, it is an exothermic reaction. Therefore, as the liquid containing at least water, only water may be used, or a mixture of alcohol or acetone and water may be used.

  Here, it is desirable to select a species azeotropic with water, such as alcohol, and use an azeotropic mixture with water. For example, the boiling point of a mixture of ethanol and water is a temperature corresponding to the composition ratio between the boiling point of water and the boiling point of ethanol. Therefore, the boiling point can be lowered as compared with the case of water alone, and the heating temperature from the outside in the endothermic process can be lowered.

  The exothermic process is performed by a solid-liquid reaction in which a liquid containing at least water is brought into contact with the heat storage material, but a solid-gas reaction in which at least water vapor is brought into contact with the heat storage material can be used in combination. In the solid-gas reaction, the calorific value per unit time is smaller than that in the solid-liquid reaction, but on the other hand, since the heat can be continuously generated for a long time, the chemical heat pump device of the present invention is used for the purpose of heat retention. It is effective for. In this case, the solid-liquid reaction and the solid-gas reaction may be performed simultaneously, or the solid-liquid reaction may be performed after the solid-gas reaction.

  The condensation container condenses and stores the vapor desorbed from the heat storage material in the endothermic process. The condensing container preferably includes a heat insulating means for keeping the contents warm. Since at least the liquid containing water or water vapor is kept warm by the heat insulating means, the initial temperature in the heat generation process is increased and the heat generation efficiency is increased. Further, since the vapor pressure in the condensing container is increased, there is an effect that the flow velocity flowing through the first flow path is improved. As this heat insulation means, there are a method in which the condensing container is made into a double structure and is insulated with an air layer or a vacuum layer, and a method in which the condensing container is covered with a foam to insulate.

  The reaction container is divided into a case where it is better to insulate according to the use and a case where it is better not to insulate.

  In the chemical heat pump device of the present invention, the condensing container and the reaction container are connected by at least two of the first flow path and the second flow path. The liquid containing at least water stored in the condensing container flows toward the reaction container through the first flow path. In order to supply the liquid, it is difficult to supply the liquid with a differential pressure as in the case of gas, so a supply means is necessary. As the supply means, the condensing container can be placed at a position higher than the reaction container and supplied by gravity, or various pumps can be used. If the method of supplying by gravity is used, the generation of noise can be suppressed because a pump is unnecessary. It is desirable that the first flow path is also insulated.

  In the second flow path, a gas containing at least water vapor flows between the condensation container and the reaction container. Since the second flow path is configured to circulate gas and can be circulated by differential pressure, a pump or the like can be omitted. In the second flow path, a gas containing at least water vapor desorbed from the heat storage material in the endothermic process is mainly circulated. However, when a solid-gas reaction is used in the exothermic process, the condensing container is used in the exothermic process. A gas containing at least water vapor flows from the reactor toward the reaction vessel. This second flow path is also divided into a case where it is better to insulate according to the use and a case where it is better not to insulate.

  In the chemical heat pump device of the present invention, it is desirable that the entire system including the condensing container, the reaction container, the first flow path, and the second flow path be in a reduced pressure atmosphere. Since the boiling point of the liquid containing at least water falls by setting it as a reduced pressure atmosphere, the heating temperature in an endothermic process can be made low similarly to the case where an azeotropic mixture is used. Although there is no restriction | limiting in particular in the grade of pressure reduction, in order to make the heating temperature in an endothermic process low, the one near a vacuum is desirable.

  Hereinafter, the present invention will be described specifically by way of examples.

  FIG. 3 shows a chemical heat pump apparatus according to this embodiment. This chemical heat pump device is used for heating engine coolant of automobiles.

  This chemical heat pump apparatus is composed of a reaction vessel 1, a condensing vessel 2, a first flow channel 10 and a second flow channel 20, and the entire system is preliminarily reduced to −98 KPa or less by a vacuum pump (not shown). ing. A heat storage material 11 made of granular or powdered calcium chloride is stored in the reaction vessel 1, and water 21 is stored in the condensation vessel 2. The reaction vessel 1 and the condensation vessel 2 are covered with heat insulating materials 12 and 22 such as glass wool.

  The first flow path 10 extends from the liquid phase portion in the condensation container 2 and is connected to a nozzle 13 disposed in the reaction container 1. A pump 14 and a valve 15 are provided in the first flow path 10. The second flow path 20 communicates with the gas phase portion of the reaction vessel 1 and the gas phase portion of the condensation vessel 2. A valve 23 is provided in the second flow path.

  A heat exchanger 3 is disposed in the reaction vessel 1, and engine cooling water flows through the heat exchanger 3. Between the engine 100 and the radiator 101, a cooling water passage 103 through which engine cooling water is circulated by a water pump 102 is formed. The heat exchanger 3 is connected to the cooling water flow path 103, and engine cooling water circulating in the cooling water flow path 103 flows through the heat exchanger 3 to exchange heat energy with the heat storage material 11. The heat energy of the engine coolant is also supplied to the heater core 104 for heating.

  A method of using the chemical heat pump apparatus according to this embodiment configured as described above will be described.

<Fever process>
First, the engine 100 is started and the water pump 102 is driven. If the temperature of the engine coolant is, for example, 35 ° C. or less, the valve 15 is “opened” and the pump 14 is driven. As a result, liquid water 21 stored in the condenser 2 is directed to the reaction vessel 1 through the first flow path 10 and sprayed from the nozzle 13 onto the heat storage material 11. Then, the heat storage material 11 generates heat by a chemical reaction (dissolution reaction), and the heat energy is transmitted to the engine cooling water via the heat exchanger 3. Therefore, the engine coolant can be heated immediately and the output and fuel consumption at the time of starting the engine are improved. Further, since the heater core 104 is also heated immediately, the vehicle interior can be heated quickly.

  When the temperature in the reaction vessel 1 is lower than the temperature in the condensation vessel 2, the water vapor in the condensation vessel 2 flows into the reaction vessel 1 through the second flow path 20 by opening the valve 23. As a result, a chemical reaction occurs in the heat storage material 11. Since the chemical reaction with water vapor has a slower reaction rate than the chemical reaction with liquid water, the exothermic heat in the exothermic process is mainly chemical reaction with liquid water.

<Endothermic process>
When the warm-up is completed after the engine is started, the pump 14 is stopped and the valve 15 is closed. When the engine cooling water reaches, for example, 50 ° C. or higher, water vapor is generated from the heat storage material 11 by a dehydration reaction. Then, since the internal pressure of the reaction vessel 1 is increased, the water vapor is directed to the condensation vessel 2 through the second flow path 20, and part or all of the water vapor is condensed and stored in the condensation vessel 2. On the other hand, the heat storage material 11 becomes a heat storage state by dehydration.

  When the engine is stopped, the valve 23 is closed. By doing so, it is possible to reliably prevent the reaction between the heat storage material 11 and water, and prepare for the next heat generation process.

  FIG. 4 shows a chemical heat pump apparatus according to this embodiment. This chemical heat pump device is used for heating automobile engine oil.

  This chemical heat pump apparatus is composed of a reaction vessel 1, a condensing vessel 2, a first flow channel 10 and a second flow channel 20, and the entire system is preliminarily reduced to −98 KPa or less by a vacuum pump (not shown). ing. A heat storage material 11 made of granular or powdered calcium sulfate is stored in the reaction vessel 1, and water 21 is stored in the condensation vessel 2.

  The reaction vessel 1 is made of metal having excellent thermal conductivity, and is disposed in the engine oil 40 of the oil pan 4 without being covered with a heat insulating material. As shown in FIG. 5, fins 16 in which two punching metals are opposed to each other with a gap are radially arranged in the reaction vessel 1, and the heat storage material 11 is stored in a small chamber partitioned by the fins 16. Yes. A gap 17 is formed in each fin 16, and the gap 17 communicates with a punching hole 18 of a punching metal.

  The condensation container 2 is the same as that of Example 1 except that it is not covered with a heat insulating material. The configurations of the first channel 10 and the second channel 20 are the same as those in the first embodiment.

<Fever process>
When the engine is started in winter, the temperature of the engine oil 40 is low, so that the lubrication performance is low and the fuel consumption is deteriorated. Therefore, when the temperature of the engine oil 40 is, for example, 40 ° C. or lower, the valve 15 is opened and the pump 14 is driven. As a result, liquid water 21 stored in the condenser 2 is directed to the reaction vessel 1 through the first flow path 10 and sprayed from the nozzle 13 onto the heat storage material 11. Then, the heat storage material 11 generates heat by a chemical reaction (hydration reaction), and the engine oil 40 is immediately heated by the heat energy. Therefore, the output and fuel consumption at the time of engine start are improved. When a predetermined amount of water 21 is supplied to the heat storage material 11, the pump 14 is stopped and the valve 15 is closed.

  At this time, the sprayed water penetrates through the punch holes 18 from the gaps 17 of the fins 16. Therefore, since the contact area with the heat storage material 11 is large, the heat generation amount per unit time is large, and the engine oil 40 can be heated quickly.

<Endothermic process>
Since the engine oil 40 becomes hot while the automobile is running, water vapor is generated from the heat storage material 11 by a dehydration reaction, condenses through the second flow path 20 and is stored as liquid water in the condensation container 2. . After the dehydration reaction of the heat storage material 11 is completed, the heat storage state is maintained. A part of the generated water vapor enters the gap 17 through the punch hole 18 of the fin 16 and travels to the second flow path 20 through the gap 17. Accordingly, water vapor dehydrated from the heat storage material 11 in the deep part is easily removed, and the heat storage amount of the heat storage material 11 increases, so that the heat generation amount in the next heat generation process increases.

  Note that the valve 23 is “closed” at an appropriate timing such as when the engine is stopped or when the temperature of the engine oil 40 starts to decrease. By so doing, it is possible to reliably prevent a hydration reaction from occurring in the heat storage material 11, and to maintain a sufficient amount of heat storage.

  Further, when the temperature of the engine oil 40 is equal to or higher than a set temperature such as 40 ° C. when the engine is started, the valves 23 and 15 are closed and the pump 14 is not driven. However, even in this case, when the temperature of the engine oil 40 is equal to or higher than the second set temperature such as 55 ° C., for example, it is preferable that the valve 23 is “open” to cause the heat storage material 11 to further dehydrate.

  In this embodiment, a punching metal is used as the material of the fins 16, but a nonwoven fabric or a mesh may be used, and a foamed metal or a sintered metal may be used.

  In the chemical heat pump apparatus of this embodiment shown in FIG. 6, the condensation container 2 is covered with a heat insulating material 22, the same calcium chloride as in the first embodiment is used as the heat storage material 11, and the metal is used instead of the fins 16. Example 2 is the same as Example 2 except that the ribbon-made aggregate 19 was placed in the reaction vessel 1.

  According to the chemical heat pump apparatus of the present embodiment, since the condensing container 2 is covered with the heat insulating material 22, the water 21 in the condensing container 2 can be kept warm. Therefore, in the heat generation process, water having a temperature higher than that of the second embodiment can be sprayed on the heat storage material 11, so that the initial temperature of the heat storage material 11 is increased, so that the heat generation efficiency is increased. Further, since the vapor pressure in the condensing container 2 is increased, the flow rate flowing through the first flow path 10 is increased by closing the valve 23 so that a large amount of water can be supplied to the heat storage material 11. These effects increase the amount of heat generated per unit time.

  And according to the chemical heat pump apparatus of the present embodiment, since the metal ribbon assembly 19 is arranged in the reaction vessel 1, a gap is generated between the heat storage material 11 and the assembly 19, so that The same effect as the fin 16 is produced.

  The chemical heat pump device of the present invention can be used for immediate warming-up, rapid cooling / heating at the start of prime movers such as automobiles, agricultural machinery, and industrial machinery, heating and keeping warm of engine coolant or oil, and prevention of freezing of fuel cells. .

1: Reaction vessel 2: Condensation vessel 3: Heat exchanger 4: Oil pan
10: First flow path
11: Thermal storage material
20: Second flow path

Claims (5)

A condensing container;
A reaction container containing a heat storage material that generates heat by a chemical reaction with a liquid containing at least water and absorbs heat by a dehydration reaction;
A first flow path through which a liquid containing at least water stored in the condensing container flows toward the reaction container;
Supply means for supplying a liquid containing at least water stored in the condensing container to the reaction container through the first flow path;
A chemical heat pump device comprising: a second flow path through which a gas containing at least water vapor generated in the reaction vessel flows toward the condensation vessel.   The chemical heat pump apparatus according to claim 1, wherein the entire system including the condensing container, the reaction container, the first flow path, and the second flow path is in a reduced pressure atmosphere.   The chemical heat pump device according to claim 1 or 2, wherein the liquid containing at least water is an azeotropic mixture of water and alcohol.   The chemical heat pump device according to any one of claims 1 to 3, wherein the condensing container includes heat insulating means for keeping the contents of the condensing container warm.   The chemical heat pump device according to any one of claims 1 to 4, wherein the first flow path is opened, a liquid containing at least water is supplied to the heat storage material by the supply means, and the heat medium is heated by heat generated by a chemical reaction. And a heat absorption step of condensing a gas containing at least water vapor generated by a dehydration reaction by heat from the heat medium by opening the second flow path and storing the condensed gas in the condensing container. How to use the heat pump device.

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