JPH0121005B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention utilizes the properties of a compound of water and zeolite as a heat source, for example in a car, using waste heat generated by an automobile engine without using a compressor. The present invention relates to a cooling method that can cool the room.

[Conventional technology]

Conventionally, the following methods are known as methods for cooling the inside of an automobile (see Introduction to Automotive Heat Management, edited by Hoshimitsu, published by Sankaido).

First, a compressor driven by a V-belt attached to the engine highly compresses the refrigerant coming in from the evaporator, and the thus compressed refrigerant is sent to the condenser (radiator).

Next, in the condenser, the refrigerant sent from the compressor is cooled and liquefied.

Furthermore, the liquefied refrigerant is sent to an evaporator to remove heat of vaporization from the air inside the vehicle, and the refrigerant itself turns into a gas, cooling the interior of the vehicle.

The refrigerant that has become gaseous in this way is
It is sent to the compressor, and the steps up to this point are repeated again.

[Problem that the invention seeks to solve]

However, in these conventional methods of cooling automobiles, the compressor is driven by engine power, which increases the engine load during cooling, increases fuel consumption, and impairs acceleration performance. becomes worse.

There were problems with air conditioning not being possible when the engine was rotating at low speeds or when the engine was stopped.

[Means for solving problems]

In view of these points, the present invention focuses on the fact that an exothermic reaction when water is adsorbed to zeolite and an endothermic reaction when water is desorbed from zeolite occur reversibly, and utilizes this reaction. It has come to completion.

Zeolite contains significantly more water of crystallization than other minerals, and as it is also called zeolite, it continuously emits water vapor when heated, and its crystal structure is destroyed even after dehydration. It becomes porous without being heated, and when it stops heating and its temperature drops, it adsorbs water vapor from the outside.

The unit cell of crystalline zeolite is the unit cell formula
MeO・Al ₂ O ₃・mSiO ₂・nH ₂ O (Me is a metal ion,
n is the number of molecules of crystal water), and when the m value is about 2, it is called A-type synthetic zeolite, when the m value is about 2.5, it is called X-type synthetic zeolite, and when the m value is about 3.5 to 6, it is called Y-type synthetic zeolite. It is something that will be done. In addition to synthetic zeolites, various natural zeolites are also known.

The basic structure of zeolite is the SiO ₄ tetrahedron of methane, which is the basic structure of silicates, and the oxygen molecules at the vertices of this SiO ₄ tetrahedron are shared with each other and undergo sequential condensation. In addition, zeolite belongs to tectosilicates with a high degree of condensation, and has a methane type structure.
It has a three-dimensional network structure in which SiO ₄ and AlO ₄ tetrahedra are combined. In this structure, the O/(Si+Al) atomic ratio of the zeolite is 2, and the overall charge only compensates for the lack of charge on the AlO ₄ tetrahedron caused by replacing Si ⁴⁺ with Al ³⁺ . of alkali or alkaline earth metal ions are bound.

In some of the pores of this three-dimensional network structure,
It has significantly larger pores than other minerals, and its cavities contain pores of a certain diameter arranged in a ring of oxygen atoms. Crystal water is contained within these cavities or pores, and can be freely desorbed by heating or depressurizing without destroying the crystal lattice structure.Moreover, if the dehydrated zeolite is kept in a high humidity state again, water can be adsorbed. It will return to the state it was in.

Of the more than 40 commercially available zeolites that can be used, 3A, 4A, 5A, and 13X are advantageous. For example, in the case of 4A, the pore diameter is 4 Å, and the amount of crystal water adsorbed differs depending on the pore diameter, and the amount of crystal water differs depending on the crystal structure. Furthermore, since thermal structural stability differs depending on the crystal structure of various zeolites, the most advantageous zeolite can be selected in consideration of price and other factors.

That is, the present invention supplies heat to a compound of water and zeolite to evaporate water from the compound, and after condensing and liquefying the evaporated water, the liquid water becomes gaseous water vapor. The object is cooled by the heat of vaporization.

[Effect]

This eliminates the need for a compressor that must be driven by engine power, which eliminates the negative effects of the engine, and also allows the cooling condition to change depending on the engine condition. There will be no such thing as doing.

〔Example〕

An embodiment of the cooling method according to the present invention will be described below with reference to the drawings.

First, a case where 4A type synthetic zeolite is used as the zeolite will be explained. Water adsorption amount of 4A type synthetic zeolite (wt for 100g of zeolite)
Figure 4 shows the changes in temperature and pressure with respect to (%).
For these characteristics, the actual cooling operating temperature,
The pressure is shown in Figure 2. As is clear from Figure 5, at point A in the figure, zeolite that has adsorbed a large amount of water (approximately 16.5 wt% moisture in 100 g of zeolite) is heated with a heat source, and water vapor is expelled until it reaches point B in the figure. , water vapor is condensed at a temperature of 80°C at point E in the figure. At point B in the figure, zeolite with a water vapor content of about 5.9wt% is cooled by the outside air, and at point C in the figure it adsorbs the water that was condensed and liquefied at point E. On the other hand, water is absorbed at point F in the figure, which is about 5℃ It evaporates and cools the object by the amount of the latent heat of evaporation. Adsorbs water vapor and has a water content of approx.
The zeolite that has reached 16.5 wt% (point D in the figure) is heated by a heating source and returns to point A in the figure, is heated again by the heat source, desorbs water vapor, and goes to point B in the figure, where the cycle continues.

Therefore, in the case of type 4A synthetic zeolite, if there is a heating source of approximately 280°C or higher and outside air that discards the heat, cooling can be achieved using a compound of water and zeolite.

Note that the cycle shown in FIG. 5 is an example, and the same effect can be obtained by changing the interval between points A and B in the figure, that is, the operating width of the water refrigerant.

Next, the above-mentioned cooling method will be specifically explained.

Similar to the principle of commercially available rotary dehumidifiers, by rotating the rotor with a drive device, the desorption/regeneration part containing the water and zeolite compound inside the rotor is spatially connected to the rotor. The desorption reaction and condensation reaction of water occur respectively with the condensed portion of the water vapor. In addition, by rotating the rotor, a reverse process of adsorption and evaporation reaction occurs, returning the water and zeolite compound to the original state.The rotor is then rotated again to cause desorption and condensation at the position of the initial desorption and condensation process. cause a reaction. In this way, the rotor can be rotated for continuous operation.

FIG. 3 shows a schematic diagram of the flow of heat in the rotating rotor. Rotor 1 containing water and zeolite compound
rotates, and heat input from the heat source, discharge to the outside air, and heat input from the object to be cooled are exchanged directly through the air medium. When the rotor is in the position shown in Figure 3, heat is supplied from the heat source to the outer periphery of a portion of the upper half of the rotor, and other heat inputs and outputs also take place at the positions shown in Figure 3. ing. Inside the rotor 1, as shown in FIG. 1, a plurality of independent closed containers 2 shown by diagonal lines in the figure are arranged radially around the central axis of the rotor. The air medium for heat exchange is allowed to pass through the gap between each of the airtight containers 2, and the water in the airtight container 1,
and heat exchange with water and zeolite compounds.

As shown in FIG.
It is divided into an outer peripheral part 2a which is an adsorption part and a central part 2b which is a condensation-evaporation part. In the outer peripheral part 2a, the molded body 3 of water and zeolite is brought into close contact with the container wall for easy heat exchange, and a space is provided between each wall through which water vapor can pass, and the center A water-absorbing agent 4 such as cloth or sponge that retains water is housed in the portion 2b.

By doing this, the molded body 3 of water and zeolite is heated by the heat source, water vapor is generated from the molded body 3, and is condensed and liquefied by the water absorbing agent 4, which serves as a condensing agent, and the condensation heat generated thereby. is radiated to the outside air. As the rotor 1 rotates, the water in the water-absorbing agent 4 takes heat from the object to be cooled and evaporates, and the water vapor is adsorbed again by the water and the biolite molded body 3, and the heat of adsorption is released to the outside air. will be done. Therefore, continuous operation can be achieved by repeating this operation.

In the above example, a continuous cycle can be constructed by rotating the container containing the water and zeolite compound.
A similar effect can be obtained by continuously changing the course of the air heat medium itself for heat exchange.

In the embodiments described above, the container containing the water and zeolite compound was vacuum degassed, and only water vapor was enclosed as the gas. Therefore, the rate of adsorption and desorption of water vapor onto the zeolite can be increased.

In addition, in the above example, the heat of desorption of water from the compound of water and zeolite is approximately 1050 kcal/Kg, and the latent heat of vaporization of water is approximately 600 kcal/Kg. Since the latent heat/desorption heat is approximately 0.57, it has an advantageous effect especially when installed in a car to cool the inside of the car.
In this case, it becomes possible to effectively utilize engine waste heat as a heat source.

〔Effect of the invention〕

As is clear from the above explanation, according to the cooling method according to the present invention, there is no need for a compressor that must be driven by engine power, so that the adverse effects on the engine side can be eliminated. Furthermore, the cooling condition does not change depending on the engine condition.

[Brief explanation of drawings]

FIG. 1 is a general view of a rotor used in an embodiment of the cooling method according to the present invention, FIG. 2 is a sectional view of a sealed container incorporated in the rotor, and FIG. 3 is a diagram explaining the function of the rotor. Figure 4 is a graph showing changes in temperature and pressure with respect to the water adsorption amount of the zeolite used in the present invention, and Figure 5 is a graph showing actual cooling operating temperature and pressure with respect to the characteristics shown in Figure 4. be. 1... Rotor, 2... Airtight container, 3... Zeolite molded body, 4... Water absorbing agent.

Claims (1)

[Claims] 1 Heat is supplied to a compound of water and zeolite to evaporate water from the compound, and the evaporated water is condensed and liquefied, and then the heat of vaporization required when the liquid water becomes gaseous water vapor is A cooling method characterized by cooling an object to be cooled.