JP3508549B2 - Heat storage device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a device for efficiently storing heat by a hydrate. More specifically, the present invention relates to a device for efficiently storing heat by optimizing a cooling temperature range of a refrigeration system and a temperature range in which a hydrate is formed.

[0002]

2. Description of the Related Art Conventionally, various heat storage devices for use in, for example, air conditioning equipment have been developed. By using such a heat storage device, for example, late-night power, or exhaust heat of the factory, the heat is stored by using energy discontinuous supply, by using the stored cold heat in the air conditioning equipment, Energy can be used more effectively.

An example of such a heat storage device is a heat storage device using ice. There is a system in which ice is manufactured at night by electric power or the like at midnight and the cold heat stored in the ice is used for air conditioning equipment in the daytime. This one is
Compared with the case of using the sensible heat of water, a large amount of cold heat can be stored by the latent heat of ice.

However, this ice heat storage device has the following problems. Firstly, since the ice produced is solid, it is difficult to store and transport it.
For this reason, for example, it is impossible to supply the stored ice as it is to a heat exchanger or the like of the air conditioner, and the stored ice and the brine are heat-exchanged and the brine is supplied to the air conditioner. It is necessary, the equipment is complicated and the cost is high. Further, a method has also been considered in which the generated ice is made into particles, which is mixed with water to form a slurry, and the slurry is conveyed. But something like this
The melting temperature of particulate ice and the freezing temperature of water are both 0 ° C, and it is difficult to maintain this slurry in a stable and constant state, and its fluidity is also low, which makes it difficult to handle. Is.

A second problem is that, in order to produce this ice, a temperature of at least 0 ° C. or lower is required, so that the refrigerating apparatus for producing the ice has a freezing temperature of at least 0 ° C. or lower. There must be. Therefore, the type of the refrigerating apparatus is limited to a compression type refrigerating apparatus that compresses, condenses, and evaporates a refrigerant such as Freon. Since such a compression type refrigerating device requires a power source such as a motor and a turbine for driving the compressor, the form of energy to be used is limited to electric power or steam of a high temperature sufficient to drive the turbine. To be done. Therefore, the energy that can be used in the heat storage device using this ice is actually limited to midnight power or the like, and exhaust heat having a low temperature cannot be used.

The third problem is that the efficiency of the refrigerating apparatus for producing ice is relatively low. That is, in a refrigeration system, the ratio of the amount of input energy required for its operation to the amount of generated cold heat corresponds to the temperature difference between the heat absorbing part and the heat radiating part. The amount of cold energy to be generated becomes large. As described above, in order to produce ice, the temperature of the heat absorbing part must be at least 0 ° C or lower, and the medium that exchanges heat with the heat radiating part is actually the atmosphere or cold water, so that temperature Is approximately constant at about 20 ° C. Therefore, the temperature difference between the heat absorbing section and the heat radiating section becomes relatively large, and there is a limit to improving the efficiency of the refrigeration system. On the other hand,
The temperature of the cold heat source used in air conditioning equipment is 10 °
C to 15 ° C. is sufficient, and in this respect as well, there was a waste of energy utilization efficiency.

[0007]

The present invention has been made based on the above circumstances, and is capable of utilizing exhaust heat at a relatively low temperature, such as exhaust heat from a factory or the like, and is highly efficient. The heat storage device is easy to handle.

[0008]

According to the present invention as set forth in claim 1, the water of the refrigerant is evaporated and the water vapor is absorbed by an absorbing solution containing an absorbent, and the absorbing solution is heated by a heat source. An absorption type refrigerating apparatus of a refrigerating cycle for heating and evaporating water to concentrate, and as a guest compound, tetra-n-butylammonium salt, tetraiso-amylammonium salt, tetraiso-butylphosphonium salt, triiso-amyl. An aqueous solution flow system in which an aqueous solution containing at least one compound of a sulfonium salt is circulated, and the aqueous solution is cooled by the absorption refrigerating apparatus to obtain particles of the guest compound hydrate at 0 ° C. Than
It is characterized by comprising a heat exchanger which is formed at a high temperature and under atmospheric pressure to form a slurry of these particles and an aqueous solution. When the aqueous solution containing the guest compound as described above is cooled, the guest compound molecule enters the cage structure of water molecules, that is, the host structure, and an inclusion hydrate having the appearance and properties similar to ice is formed. It Such a hydrate has a large latent heat per unit weight,
It is a small heat storage device and has a large cold heat storage capacity. Also,
Since the melting temperature of the guest compound as described above is in the temperature range of 4 ° C. to 25 ° C., the temperature difference between the heat absorbing part and the heat radiating part of the refrigerating apparatus becomes small and the efficiency is improved. Further, since the temperature of the heat absorbing portion of this refrigerating device is 0 ° C. or higher, an absorption type refrigerating device using water as a refrigerant can be used. Since this absorption type refrigeration system can use relatively low temperature exhaust heat such as low temperature steam as an energy source, it can store heat by effectively utilizing the exhaust heat of the factory. The temperature at which such a hydrate is formed is 0 ° C.
From the above, the surrounding aqueous solution does not solidify, hydrate particles are generated, and a slurry of the hydrate particles and the aqueous solution is formed. Such a hydrate slurry has a large heat storage amount as described above, has high fluidity, is easy to store, and can be easily transferred by a pump or the like via a pipe or the like. Further, it is possible to directly supply the slurry as it is or to the existing air-conditioning equipment using cold water or the like with minor modification, and the equipment cost can be reduced. Further, the present invention according to claim 2 is such that the heat exchanger exchanges heat between the heat medium that has exchanged heat with the water of the refrigerant of the absorption refrigerating apparatus and the aqueous solution. Therefore, the degree of freedom of the structure of the heat exchanger that cools this aqueous solution to generate hydrate particles is large, and it is possible to obtain the optimum structure for generating a hydrate slurry having desirable properties. Further, in the present invention as set forth in claim 3, the heat exchanger directly exchanges heat between the water of the refrigerant of the absorption refrigeration apparatus and the aqueous solution.
Therefore, the structure is simple and the device can be easily miniaturized. The present invention according to claim 4 is
The aqueous solution flow system is provided with a heat storage tank for storing a hydrate slurry containing hydrate particles produced by being cooled by the heat exchanger. Therefore, a large amount of hydrate slurry can be stored in this heat storage tank, and the heat storage amount can be increased. Further, the present invention according to claim 5 is characterized in that the heat from the heat source is exhaust heat from a factory or the like.

Further, the present invention according to claim 6 is a heat storage tank for storing an aqueous solution containing a clathrate hydrate-forming substance and a slurry in which hydrate particles are mixed, and the aqueous solution or slurry. A heat exchanger for exchanging heat with the refrigerant, wherein the heat exchange causes the temperature to be higher than 0 ° C. and the atmosphere.
The heat storage device is characterized in that a slurry containing hydrate particles generated under pressure is returned to and stored in the heat storage tank. Further, the present invention according to claim 7 is characterized in that the aqueous solution or slurry that exchanges heat with the refrigerant in the heat exchanger is an aqueous solution or slurry having a low solid phase ratio existing in the upper part of the heat storage tank. To do. Further, in the present invention according to claim 8, the clathrate hydrate-producing substance is
One or more selected from the group consisting of a tetra-n-butylammonium salt, a tetra-iso-amylammonium salt, a tetra-n-butylphosphonium salt, and a tri-iso-amylsulfonium salt. It is a thing.

The present invention according to claim 9 is characterized in that the aqueous solution contains fine particles which serve as nuclei for forming particles of the hydrate.

[0011]

Further, according to the present invention of claim 10 , an aqueous solution containing a clathrate hydrate-forming substance is heated at a temperature higher than 0 ° C.
A method of supplying a hydrate slurry produced by cooling under atmospheric pressure to a heat load side as a cooling medium, characterized in that the hydrate is produced and stored at night. Is. Further, the present invention according to claim 11 is characterized in that when the cooling load on the heat load side is large, the hydrate is produced even in the daytime. Further, the present invention according to claim 12 is a hydrate produced by cooling an aqueous solution containing a clathrate hydrate-forming substance at a temperature higher than 0 ° C. and under atmospheric pressure . A method of supplying a slurry to a heat load side as a cooling medium, characterized in that the hydrate is generated by using energy which is discontinuous in supply of midnight power, exhaust heat of a factory, and the like, and then stored. It is what Further, the present invention according to claim 13 is characterized in that the aqueous solution contains fine particles serving as nuclei for forming particles of the hydrate.

[0013]

The present invention according to claim 14 is characterized in that the slurry present in the upper part of a heat storage tank for storing a slurry of a hydrate produced by cooling an aqueous solution containing a clathrate hydrate-forming substance, or The aqueous solution is preferentially cooled to produce the hydrate, and the hydrate slurry accumulated at the bottom of the heat storage tank is supplied to the heat load side as a cooling medium. Further, in the present invention according to claim 15 , a slurry of a hydrate produced by preferentially cooling the slurry or the aqueous solution existing in the upper part of the heat storage tank and accumulated in the bottom part of the heat storage tank. It is characterized in that it is combined with a hydrate slurry and supplied as a cold heat medium to the heat load side.

[0015]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the method and apparatus of the present invention will be described below with reference to the drawings. 1 to 3 schematically show a device according to a first embodiment of the present invention. This is a heat storage device that produces a hydrate slurry as a cold heat source for an air conditioner or the like. Of course, the present invention is not limited to such applications, and may be used as a cold heat source for other applications.

In this embodiment, an absorption type refrigeration system 1 is used as a refrigeration system, and the absorption type refrigeration system 1 is used.
As a result, a cooling medium, that is, cold water of about 4 ° C. is supplied. Reference numeral 2 is a cooling tower for the absorption refrigeration system 1.

Reference numeral 3 is a heat storage tank for storing an aqueous solution of the guest compound and a hydrate slurry S in which hydrate particles are mixed. The aqueous solution in the heat storage tank 3 is a heat exchanger 4
And is cooled by being heat-exchanged with the cold water from the absorption refrigerating apparatus to generate hydrate particles, and the slurry containing the particles is returned to the heat storage tank 3 and stored therein. Then, the hydrate slurry in the heat storage tank 3 is sent to a heat load side such as an air conditioner and used as a cold heat source.

Next, the configuration of each of the above parts will be described. The absorption refrigeration system 1 described above is provided with an evaporator 10, in which water as a refrigerant is sprayed and evaporated from a nozzle 13 to form a low temperature atmosphere. This evaporator 10
A heat exchange element such as a heat transfer tube 12 is housed therein, and water is circulated between the heat transfer tube 12 and the heat exchanger 4 through the pump 11 and, for example, from the heat exchanger 4. About 1
The 2 ° C water is cooled to about 4 ° C and returned to the heat exchanger 4.

The water vapor evaporated in the evaporator 10 is sent to the absorber 15 via the pipe 14. This absorber 15
An absorbing solution in which, for example, lithium bromide is dissolved as an absorbent is contained therein, and the absorbing solution is sprayed from the nozzle 16. Then, the water vapor from the evaporator 10 is absorbed by this absorbing solution.

The absorbing solution diluted by absorbing water vapor in the absorber 15 is sent to the first generator 18 by the pump 17. A heat exchange element 20 is provided in the first generator 18, and the heat exchange element 20 is supplied with relatively low-temperature steam or the like generated by a relatively low-temperature heat source such as waste heat of a factory, The diluted absorbing solution is heated and the water is evaporated to concentrate the absorbing solution. And
The concentrated absorbing solution is sent to the second generator 22 via the pipe 21.

Further, the water vapor evaporated from the absorption solution in the first generator 18 is sent to the heat exchange element 23 in the second generator 22 to remove the absorption solution in the second generator 22. Heat to evaporate water to further concentration. The absorbing solution thus concentrated in two stages and the water vapor absorbing capacity is restored is passed through the pipe 24 to the absorber 15 described above.
It is supplied to the nozzle 16 inside and absorbs the water vapor from the evaporator 10 again.

The steam generated in the first generator 18 and the second generator 22 is sent to the condenser 26. A heat exchange element 28 is provided in the condenser 26,
Cooling water from the cooling tower 2 is supplied to the heat exchange element 28 by a pump 27. Then, the water vapor is cooled by the heat exchange element 28, condensed and returned to water, and the water is pumped by the nozzle 32 of the evaporator 10.
It is sent to No. 3 and sprayed, and it evaporates to a low temperature. The cooling water from the cooling tower 2 is passed through the pipe 29 to the absorber 1
5 is sent to the heat exchange element 31 in 5 to cool the absorbing solution and improve its water vapor absorption capacity.

In the absorption refrigerating apparatus 1, the coolant water and the absorbing solution are circulated through the above-mentioned path to supply cold water. Such an absorption refrigerating apparatus can use heat from a heat source of a relatively low temperature, and can effectively use waste heat of a factory. In addition, such an absorption refrigeration system generally has a cooling temperature of, for example, 3 ° C to 15 ° C.
Although it is in the range of ° C, by appropriately selecting the kind of the absorbent, it is possible to have a cooling capacity above this temperature range, and by mixing an antifreeze liquid or the like in the coolant water,
It is also possible to cool to a temperature below ° C.

Next, the structure of the heat exchanger 4 for producing the above hydrate slurry will be described. In this embodiment, tetra-n-butylammonium bromide (hereinafter abbreviated as TBAB) is used as a guest compound forming this hydrate. The melting point of this TBAB hydrate is 11.8.
Therefore, the aqueous solution S of TBAB produces a hydrate when cooled to 11.8 ° C. or lower. The heat of fusion of this TBAB hydrate is 40 to 50K.
It is cal / Kg, and this latent heat exerts a large heat storage capacity.

The above-mentioned guest compound is not limited to the above-mentioned ones, and tetra-n-butylammonium salt, tetra-iso-amylammonium salt, tetra-iso-butylphosphonium salt, tri-iso-amylsulfonium salt. Various compounds of clathrate hydrate-forming substances such as C.I. The hydrates of these guest compounds have melting points in the range of about 5 ° C to 25 ° C, which corresponds to the cooling temperature range of the absorption refrigeration system 1 as described above. Suitable for use in combination with refrigeration equipment.

FIG. 2 schematically shows the structure of the heat exchanger 4 for producing the above hydrate slurry. 40 in the figure
Is a cooling tank, and the aqueous solution S of TBAB in the heat storage tank 3 is supplied into the cooling tank 40 through a pipe 41, and the slurry of the aqueous solution and the hydrate particles produced is It is returned from the bottom of the cooling tank 40 to the heat storage tank 3 via the pipe 42.

In the case of this embodiment, the cooling tank 40 is an open container communicating with the atmosphere, the inside of which is maintained at atmospheric pressure, and the circulating aqueous solution S is exposed to air on its free surface. Are in contact.

Inside the cooling tank 40, a heat exchange means, that is, a heat exchange element 50 of another type such as a cooling pipe is provided. The heat exchange element 50 includes pipes 44, 45.
The cooling medium, that is, cold water, generated in the absorption refrigerator 1 is circulated through the cooling medium to cool the surrounding aqueous solution. Further, the cooling tank 40 is provided with a circulation mechanism including a pump 51, a pipe 52, etc., and circulates and circulates the aqueous solution S inside through the heat exchange element 50.

Further, in the portion where the aqueous solution S flows,
A temperature detector 51, a dissolved gas concentration detector 52, and a guest compound concentration detector 53 are provided. In this embodiment, as the dissolved gas concentration detector 52, a dissolved oxygen concentration detector is used to detect the concentration of dissolved oxygen in the aqueous solution, and the concentration of dissolved air in the aqueous solution is determined from this detected value. It is configured to measure.

An air ejection mechanism 56 is provided at the bottom of the cooling tank 40. This air ejection mechanism 56
Is equipped with an air nozzle 57, a pump 59, etc.
Air is jetted into the aqueous solution inside.

The signals from the temperature detector 51, the dissolved gas concentration detector 52 and the guest compound concentration detector 53 are sent to the controller 54. The control device 54 controls the entire device in response to signals from these detectors and other process signals. For example, the controller 54 monitors the dissolved air concentration, maintains this concentration in the above range, and the signal from the temperature detector 51 causes
The hydrate formation temperature is calculated, and the temperature of the cooling medium from the refrigeration system is controlled correspondingly.

Next, the operation of the above apparatus and the method for producing a hydrate will be described. First, prior to the production of this hydrate slurry, the concentration of the guest compound in the aqueous solution S and the dissolved gas, that is, the dissolved air concentration in the apparatus are adjusted to a predetermined range. This adjustment of the dissolved air concentration can be usually set by sufficiently contacting the air and filling the apparatus with water containing the dissolved air up to the saturation concentration.

Next, the absorption refrigerating apparatus 1 and the entire apparatus as described above are operated. Then, the aqueous solution S is cooled when passing through the heat exchange element 50 to form particles of TBAB hydrate. In this case, the above temperature detector 5
1 and the dissolved gas concentration detector 52 and the like, the concentration of the dissolved air is saturated at a temperature at which this aqueous solution S is cooled by the heat exchange element 50 to form hydrate particles, for example, at a temperature of 7 to 8 ° C. Keep it above 90% of the concentration.

By maintaining such conditions, the surface of the produced particles of TBAB hydrate is covered with a thin gas film, that is, an air film. Although the process of forming a gas film on the surface of such hydrate particles is not clear at the molecular level, it is generally formed by the following process.

First, a hydrate is formed by conjugating one molecule of a guest compound in a host structure composed of n water molecules. Usually, assuming that this host structure is composed of six water molecules, When an aqueous solution containing water molecules 6 and guest compound molecules 1 is prepared, the temperature of the mixture of the aqueous solution and the hydrate is constant and the concentration of the guest compound in the aqueous solution is constant when the aqueous solution is cooled. Produces a hydrate. The temperature in such a case is called a harmonic temperature.

When the concentration of the guest compound in the aqueous solution is lower than the above, for example, when an aqueous solution having a ratio of 1 guest compound molecule to 12 water molecules is prepared, the water molecule 6 and the guest compound molecule are as described above. Since the hydrate is formed at a rate of 1, the concentration of the aqueous solution becomes thin as the hydrate is produced, and the concentration of the aqueous solution and the hydrate production temperature increase as the amount of hydrate produced increases. It decreases.

In the case of the present invention, in any of the above cases, the concentration of the guest compound in the above-mentioned aqueous solution is such that it produces a harmonization temperature of the ratio of 1 molecule of the guest compound to 6 water molecules, or A gas film was formed on the surface of the produced hydrate particles in any of the following concentrations. The reason is considered as follows.

That is, even if the concentration of the TBAB aqueous solution is such that the above-mentioned harmonic temperature is produced,
In the localized areas where this aqueous solution comes into contact with the heat exchange elements,
First, this aqueous solution is supercooled to a temperature equal to or lower than the melting point of TBAB hydrate, and then hydrates are produced around the fine particles and other nuclei present in this aqueous solution, which become hydrate particles. In this case, more gas can be dissolved in the supercooled solution, that is, in the aqueous solution having a low temperature. Then, when the hydrate is formed, its heat of solidification is released, so that the ambient temperature locally rises. As a result, the dissolved gas in the surrounding aqueous solution is separated and adsorbed on the surface of the particles of the solvate to form a gas film.

The actual mode of this gas film differs depending on the production conditions and the like, but in addition to the case where an actual gas film is formed on the surface of the hydrate particles, the gas constitutes a part of the hydrate. Or some of the gas may be entrapped in the hydrate structure.

Further, when the guest compound, TBAB, enters the host structure of water, the dissolved gas molecules in the water are eliminated into the surrounding aqueous solution. In this case,
As the temperature of the surrounding aqueous solution locally rises as described above, the dissolvable saturation concentration decreases, and the amount of the aqueous solution decreases due to the formation of hydrates. The excluded gas is also separated from the surrounding aqueous solution.

The gas thus separated is immediately adsorbed on the surface of the produced hydrate particles, and thereafter, is stably adsorbed and held on the surface of the hydrate particles, so that the surface of the hydrate particles is thin. Covered with a gas film.

By thus forming a gas film on the surface of the hydrate particles, it is possible to prevent the hydrate particles from coming into direct contact with each other. Condensation is prevented. Further, this gas film reduces the friction between the hydrate particles, enhances the fluidity of the slurry of the mixture of the hydrate particles and the aqueous solution, and when the slurry is transferred in the pipe by a pump or the like. , Its pressure loss becomes small. In addition, the gas film reduces heat transfer between the hydrate particles and the surrounding aqueous solution, thus reducing the apparent heat transfer coefficient of the slurry. Therefore, heat loss during storage and transfer of such a slurry is reduced.

In order to cause such a phenomenon, it is necessary to control the concentration of the dissolved gas in this aqueous solution. If the concentration of the dissolved gas is too low, the gas is not separated in the above process, or the amount of the separated gas is small, and the surface of the hydrate particles cannot be sufficiently covered with the gas film. Generally, in such a device, in order to prevent corrosion of steel plates and the like that constitute the device, the aqueous solution as described above is generally sufficiently degassed to reduce the dissolved oxygen concentration. In order to form a gas film on the surface of such hydrate particles, such degassing is not preferable.

As a result of various experiments conducted on the conditions, it was found that in order to form a gas film having a thickness on the surface of the hydrate particles to the extent that the above-mentioned action can be expected, the dissolved gas in the aqueous solution should be used. The concentration was found to be above 90% of the saturation concentration at the temperature at which this hydrate was formed. This experiment was carried out in the case where the dissolved gas was air, that is, a mixed gas of nitrogen and oxygen, nitrogen and carbon dioxide, but there was no particular difference in the conditions for the difference in the types of these gases.

In a normal state, when the concentration of the dissolved gas in the aqueous solution exceeds the saturated concentration, the gas is released and released, so that the dissolved gas concentration of the aqueous solution generally exceeds the saturated concentration. There is no. Then, for the above air, nitrogen, carbon dioxide, was tested at a saturated dissolved gas concentration, in each case a gas film of sufficient thickness is formed on the surface of the hydrate particles at a saturated concentration, and There was no generation of bubbles of free gas.

In the above embodiment, the cooling tank 40 is an open container, and the free surface of the aqueous solution S is constantly in contact with air inside. Therefore, by first filling the inside of this apparatus with the aqueous solution S that has been sufficiently contacted with air to increase the saturated air concentration to near the saturated concentration, and by making the free surface of this aqueous solution S wide enough, The dissolved air concentration of is automatically maintained near the saturation concentration, and does not fall below the lower limit of 90%.

Further, in this embodiment, since the aqueous solution inside is circulated by the pump 51 of the flow mechanism so as to circulate around the heat exchange element 50, the dissolved air concentration of the aqueous solution in the cooling tank 40 and The temperature is maintained uniform, and the above control is easy and accurate.

Further, in this embodiment, the air ejection mechanism 5
Since air is jetted into the aqueous solution S from the bottom of the cooling tank 40 by 6, the inside is agitated due to the rise of the bubbles, so that the precipitation and aggregation of the hydrate particles can be prevented more reliably.
Since the concentration of the dissolved air in the aqueous solution can be increased by the ejected air, the air ejection mechanism 56 ensures that the concentration of the dissolved air in the aqueous solution is close to the saturated concentration at the same time as the stirring action as described above. The function of maintaining it can be combined.

In the above embodiment, in order to simplify the structure and facilitate handling, the free surface of the aqueous solution is brought into contact with air by using the cooling tank 40 as an open container, and the dissolved air concentration thereof is Is maintained near the saturation concentration, the flow system of the aqueous solution or slurry can be closed, and the inside pressure can be different from atmospheric pressure. Even in this case, if the free surface of the aqueous solution is formed inside, it is possible to maintain the dissolved air concentration close to the saturation concentration, and of course control the dissolved air concentration by blowing air or degassing by depressurization. It is also possible to add a mechanism for doing so.

As the dissolved gas, nitrogen or carbon dioxide may be used instead of air. By using such a gas, the corrosion of the inner wall of the device can be reduced, and the action of forming a gas film on the surface of the hydrate particles is not affected.

If the concentration of the guest compound in the above-mentioned aqueous solution is set so as to produce a harmonious temperature as described above, the concentration of the aqueous solution does not change even by the formation of hydrates. There is no particular need for concentration control.
Further, even when the concentration of the aqueous solution is lower than this, the concentration of the aqueous solution decreases as the amount of hydrate produced increases,
Since the production temperature of the hydrate decreases, it is possible to control the amount of hydrate produced by controlling the cooling temperature of the aqueous solution, and it is not necessary to control the concentration of the aqueous solution.

As described above, this apparatus can efficiently produce a hydrate slurry. Therefore, it is possible to store this hydrate slurry in the heat storage tank 3 by utilizing the exhaust heat of a factory or the like, and supply this to the air conditioning equipment, etc., and the fluctuation of the exhaust heat supply and the load of the air conditioning equipment. It is possible to eliminate the inconsistency of fluctuations in the energy and use the energy more effectively.

In this case, the hydrate slurry does not aggregate, has a high fluidity, and has a low apparent thermal conductivity, so that it can be easily stored and transferred.
Further, by utilizing the high fluidity, it is possible to supply the existing air conditioning equipment using cold water as it is or after making a small modification, and it is possible to reduce the equipment cost.

As described above, when supplying the hydrate slurry to an air conditioner or the like, a device for removing a gas film on the surface of the hydrate particles as shown in FIG. 3 can be added. . The gas film on the surface of the hydrate particles exerts the above-described action and effect, but when heat exchange is carried out between the hydrate slurry and air in a heat load, for example, a heat exchanger of an air conditioner, etc. Since the gas film reduces the apparent thermal conductivity, the heat exchange efficiency decreases. To prevent this, see Figure 3.
As shown in, a centrifugal separator 71 such as a cyclone or a tangential separator is arranged in the middle of a pipe 72 on the upstream side of the heat exchanger 70 of the air conditioning equipment, and is formed on the surface of the hydrate particles by centrifugal force. The remaining gas film is removed and the gas is discharged from the exhaust port 73. As a result, the hydrate particles come into direct contact with the aqueous solution and the apparent thermal conductivity increases, so that heat can be efficiently exchanged. The separated gas is not discharged to the outside of the system,
Fine bubbles may be left in the system.

Further, the present invention is not limited to the above embodiment, and for example, FIG. 4 shows a part of the second embodiment of the present invention. This is a kind of chiller that performs heat storage operation of a refrigerator at night to generate a hydrate and stores it, and during the daytime, performs load operation in which cold heat stored in the hydrate is used for air conditioning equipment. In this case, the refrigeration system can be operated more efficiently.

FIG. 4 shows the heat exchanger 4, the heat storage tank 3, and the pipes connected to the load side of the air conditioning equipment and the like according to the second embodiment. Reference numeral 67 in the figure denotes an outflow pipe for supplying the hydrate slurry from the heat exchanger 4 to the load side such as an air conditioner, 6
Reference numeral 8 is a return pipe from the load side. A switching valve 66 is provided in the middle of the forward pipe 67, and communicates with the heat storage tank 76 via the pipe 76. Further, a pump 65 is provided which sucks up the hydrate slurry from the bottom of the heat storage tank 3 and supplies it in the middle of the forward pipe 67.
Further, a switching valve 69 is provided in the middle of the return pipe 68 and communicates with the upper portion of the heat storage tank 3 via a pipe 75.

In this embodiment, an aqueous solution having a low concentration which does not produce the above-mentioned harmonious temperature is used. Since such an aqueous solution is not entirely formed into a hydrate, a hydrate slurry can be surely formed.

In FIG. 4, the solid arrows show the flow of the hydrate slurry during the heat storage operation at night, and the broken arrows show
The flow of the hydrate slurry in the case of load operation in the daytime is shown.

First, in the heat storage operation, the aqueous solution flows from the heat storage tank 3 to the pipe 75, the switching valve 69, the pipe 41, and the pump 43.
Is sent to the heat exchanger 4 and cooled to generate a hydrate slurry, which is a switching valve 66 and a pipe 7.
It is returned to the bottom of the heat storage tank 3 via 6. Since the hydrate particles have a larger specific gravity than the aqueous solution, the hydrate particles in this slurry are accumulated at the bottom of the heat storage tank 3.

In the daytime load operation, the hydrate particles at the bottom of the heat storage tank 3 are sucked up by the pump 65 together with the aqueous solution, and this hydrate slurry is loaded through the forward pipe 67 into the load of the air conditioning equipment or the like. The hydrate slurry that has been sent to the load side and exchanged heat on the load side is returned to the heat storage tank 3 via the return pipe 68, the switching valve 69, and the pipe 75.

When the cooling load is large during the daytime load operation, the refrigerating apparatus is operated in parallel, and a part of the hydrate slurry in the return pipe 68 is partly branched by the switching valve 69. , Heat exchanger 4 through pipe 41 and pump 43
And cooled to produce hydrate particles. Then, the hydrate slurry sent out from the heat exchanger 4 is
It is returned to the above-mentioned outflow pipe 67 via the switching valve 66, merges with the hydrate slurry sucked from the heat storage tank 3 by the pump 65, and is supplied to the load side.

In this embodiment, the operating efficiency of the refrigeration system can be improved. That is, as the amount of hydrate particles in the aqueous solution increases, the concentration of the aqueous solution decreases and the hydrate formation temperature decreases, so the temperature of the endothermic part of the refrigerating apparatus also decreases correspondingly. This refrigeration system saves energy by controlling so. Further, in this embodiment, the hydrate particles are always stored in the heat storage tank 3
Since it is accumulated at the bottom of the heat storage tank and separated from the aqueous solution, a hydrate slurry or an aqueous solution having a low solid phase ratio is present at the upper portion of the heat storage tank 3.

Therefore, when the heat storage operation is performed,
That is, when the aqueous solution circulates along the path indicated by the solid line arrow in the figure, the hydrate slurry or aqueous solution having a low solid phase ratio in the upper part of the heat storage tank 3 is preferentially sent to the heat exchanger 4, so that the piping, The pressure loss in the heat exchanger can be reduced and the heat transfer property in the heat exchanger can be improved.

Also, when the refrigeration system is operated in parallel during the daytime load operation as described above, heat exchange is performed on the load side to melt the hydrate particles, resulting in an increase in concentration and temperature. Since the aqueous solution is preferentially sent to the heat exchanger 4, the temperature at which hydrate particles are generated from this aqueous solution becomes high, and the temperature of the heat absorbing part of the refrigerator is increased to make the temperature difference from the heat radiating part. It can be made small, and the operation efficiency of the refrigeration system is improved.

As the amount of hydrate particles accumulated in the heat storage tank 3 increases, the concentration of the aqueous solution decreases, the hydrate formation temperature also decreases, and the efficiency of the refrigerating apparatus also decreases. However, if the capacity of the heat storage tank 3, that is, the total amount of the aqueous solution is appropriately set in accordance with the capacity of the load side of the air conditioning equipment, the capacity of the refrigerating device, etc., it will always be as described above under normal operating conditions. It is possible to operate the refrigeration system in a highly efficient range.

Further, FIG. 5 shows a third embodiment of the present invention. In this device, a heat exchanger 80 is provided in place of the evaporator of the absorption refrigeration system 1 of the first embodiment, and water of the refrigerant evaporated in the heat exchanger 80 and an aqueous solution such as TBAB are provided. Heat is directly exchanged and the aqueous solution is cooled to form a hydrate slurry. It should be noted that this embodiment has the same configuration as that of the above-described first embodiment except for the above points.
In the figure, the parts corresponding to those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Furthermore, the present invention is not limited to the above embodiments. For example, the present invention is not limited to a heat storage device for air conditioning, but can be used as another industrial cold heat storage device.

Further, the structure of the heat exchanger for cooling the aqueous solution to produce the hydrate is not necessarily limited to the above-mentioned one, but one having another structure is adopted according to the design specifications and the like. It is possible.

[0069]

As described above, according to the present invention, since cold heat is stored by the hydrate, a large heat storage capacity can be exhibited and the device can be downsized. Also, by selecting a guest compound that forms this hydrate,
Its production temperature range is from 4 ° C to 25 ° C, which corresponds to the optimum cooling temperature range of the absorption refrigeration system. Therefore, it is possible to use an absorption type refrigeration system that can utilize exhaust heat of a relatively low temperature, and it is possible to use energy more efficiently. Furthermore, the hydrate formation temperature range is 0 ° C. or higher and a temperature sufficient as a cold heat source for air-conditioning equipment, etc., and the temperature difference between the heat absorbing part and the heat radiating part of the absorption refrigeration system is small. , Its efficiency is improved. Furthermore, since the hydrate formation temperature is 0 ° C. or higher, the hydrate particles are formed in the aqueous solution to form a slurry, which is easy to store and transfer. is there.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a part of the heat exchanger of the first embodiment.

FIG. 3 is a schematic configuration diagram of a part of the centrifuge of the first embodiment.

FIG. 4 is a schematic configuration diagram of a part of the second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a third embodiment of the present invention.

[Explanation of symbols]

1 Refrigerator 3 heat storage tank 4 heat exchanger 40 cooling tank 50 heat exchange elements 52 Dissolved gas concentration detector S aqueous solution

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-163735 (JP, A) Japanese Patent Publication No. 8-32873 (JP, B2) Patent 2512095 (JP, B2) Naritake Kawasaki and 1 other person, gas water Application of cold heat storage material of Japanese products, chemical engineering, Vol. 27, No. 8, P. 603 (58) Fields surveyed (Int.Cl. ⁷ , DB name) F28D 20/00 C09K 5/06 F24F 5/00 101 F24F 5/00 102

Claims (15)

(57) [Claims] 1. An absorption in a refrigeration cycle in which water of a refrigerant is evaporated and this water vapor is absorbed by an absorbing solution containing an absorbent, and the absorbing solution is heated by heat from a heat source to evaporate and condense water. Type refrigeration system and guest compounds such as tetra-n-butylammonium salt and tetra-iso-
An aqueous solution flow system for circulating an aqueous solution containing at least one compound selected from the group consisting of amyl ammonium salt, tetra iso-butyl phosphonium salt, and tri iso-amyl sulfonium salt, and the above aqueous solution by the absorption refrigerating apparatus. A heat exchanger for cooling to form particles of the guest compound hydrate at a temperature higher than 0 ° C. and under atmospheric pressure, and forming a slurry of the particles and an aqueous solution. Heat storage device. 2. The heat storage device according to claim 1, wherein the heat exchanger exchanges heat between the heat medium that has exchanged heat with the water of the refrigerant of the absorption refrigeration apparatus and the aqueous solution. apparatus. 3. The heat storage device according to claim 1, wherein the heat exchanger directly exchanges heat between the refrigerant water of the absorption refrigeration system and the aqueous solution. 4. A heat storage tank for storing a hydrate slurry containing hydrate particles produced by being cooled by the heat exchanger, is provided in the aqueous solution flow system. The heat storage device according to claim 1. 5. The heat storage device according to claim 1, wherein the heat from the heat source is exhaust heat from a factory or the like. 6. A heat storage tank for storing an aqueous solution containing a clathrate hydrate-forming substance and a slurry in which hydrate particles are mixed with the aqueous solution, and heat for exchanging heat between the aqueous solution or the slurry and a refrigerant. And a heat exchanger, wherein a slurry containing particles of hydrate generated at a temperature higher than 0 ° C. and under atmospheric pressure by the heat exchange is returned to and stored in the heat storage tank. apparatus. 7. The heat storage device according to claim 6, wherein the aqueous solution or slurry that exchanges heat with the refrigerant in the heat exchanger is an aqueous solution or slurry having a low solid phase ratio existing in the upper portion of the heat storage tank. . 8. The clathrate hydrate-forming substance is tetra-n-
7. One or more selected from the group consisting of butylammonium salt, tetra-iso-amylammonium salt, tetra-n-butylphosphonium salt, and triiso-amylsulfonium salt. Or the heat storage device according to 7. 9. The heat storage device according to claim 1, further comprising fine particles serving as nuclei for forming the hydrate particles. 10. An aqueous solution containing a clathrate hydrate-forming substance is set to 0.
A method of supplying a hydrate slurry produced by cooling at a temperature higher than ℃ and under atmospheric pressure to a heat load side as a heat transfer medium, wherein the hydrate is stored at night after production. A method characterized by the following. 11. The method according to claim 10, wherein when the cooling load on the heat load side is large, the hydrate is produced even in the daytime. 12. An aqueous solution containing a clathrate hydrate-forming substance is set to 0.
A method of supplying a hydrate slurry produced by cooling at a temperature higher than ℃ and under atmospheric pressure to the heat load side as a heat transfer medium, and discontinuous supply of late-night power, waste heat from a factory, and other supplies. A method characterized in that the hydrate is produced using energy and then stored. 13. The method according to claim 10, wherein the aqueous solution contains fine particles serving as nuclei for forming particles of the hydrate. 14. An aqueous solution containing a clathrate hydrate-forming substance is cooled.
Store the hydrate slurry produced by discarding
The slurry or the aqueous solution present in the upper part of the heat storage tank
Preferentially cools to form the hydrate, the bottom of the heat storage tank
Load of hydrate slurry accumulated in the room as a cooling medium
How to supply to the side. 15. The slurry existing above the heat storage tank.
Or a hydrate produced by preferentially cooling the aqueous solution
Slurry and the hydrate soot accumulated at the bottom of the heat storage tank.
Combines with the rally and supplies it to the heat load side as a cooling medium.
15. The method of claim 14, wherein the method comprises: