JPS6356431B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention was filed in July 1972 by the same applicant as the present case.
This invention utilizes Patent Application No. 80323 of 1972 (title of invention: ``Method for increasing thermal separation effect weight by combining different types of diffusion media'') filed on the 18th.

The previously filed invention aims to apply to various physical and chemical operations by superimposing the transport phenomenon of atoms, molecules, and ions due to thermal diffusion and enhancing the effect, but the present invention Among these, it is particularly concerned with the application of this to the transport of gas molecules, in which a porous material is used as a diffusion medium and a diffusion material is created by connecting a large number of structures called thermal diffusion pairs, which will be detailed later. This invention relates to a gas transportation and compression device.

Thermal diffusion occurs when a temperature gradient exists in a substance.
This is a well-known phenomenon in which particles move along the gradient, resulting in uneven distribution of diffused particles and a difference in concentration.

If a temperature gradient is applied to a thermal diffusion pair or a thermal diffusion pair that applies this thermal diffusion, it is possible to separate the component gases in the case of a mixed gas, but this can be seen from another perspective. This shows that gas can be compressed. In other words, gas molecules can be transported from one system to the other by providing a temperature gradient to the thermal diffusion pair and the thermal diffusion pair, and if we look at this for each component molecule of the system, the transport ability differs for each molecule. A mixture of gases can be separated because one component becomes dense in one system and sparse in the other, and if we ignore the components of the system and look at the whole system, one system becomes denser and the other system becomes sparser. One system will be compressed and the other system will be depressurized.

The present invention is to perform gas transport compression by applying thermal diffusion to a thermal diffusion pair and by applying a temperature gradient to the thermal diffusion pair.

Conventionally, for the transportation and compression of gas, there are various mechanical pumps that are mainly driven by electric motors, and depending on the magnitude of the discharge pressure,
They are classified into ventilators, blowers, and compressors. In addition, there is a vacuum pump that is intended to transport gas from the opposite perspective and whose purpose is to reduce pressure. In addition to mechanical rotary pumps, vacuum pumps include oil diffusion pumps that use oil droplets to capture gas molecules in the exhaust system. These pumps, which transport and compress gases, are used for various gases including air, and in addition to transporting gases, they are also used for refrigeration and cooling equipment, gas liquefaction equipment, supply of compressed gas to chemical processes, It is used for purposes such as air pressure sources for pneumatic equipment. In the past, various types have been devised, and it has now become possible to have a wide range of choices depending on the conditions of use. However, vibrations and noise caused by mechanical drive are unavoidable for mechanical pumps, and depending on the application, it may be undesirable to mix lubricating oil or other contaminants into the compressed gas or vacuum exhaust system.

Also, energy such as electricity is consumed during drive, but from the perspective of energy conservation and energy development in recent years, if gas transport and compression can be performed by using low-quality thermal energy, it will provide a way to use it as a resource. , it is thought that it will make a great contribution to industry.

The present invention has been made in view of the above-mentioned problems, and provides a novel gas transport and compression device that applies thermal diffusion and connects a large number of thermal diffusion pairs using porous materials as diffusion media. The purpose is to compress and transport the component gases of the molecules that diffuse through them. The heat diffusion couple according to the present invention does not require any mechanical equipment, so there is no noise, vibration, etc. in mechanical gas compression equipment, and it does not require lubricating oil, so it does not require any lubricating oil etc. Because there is no contamination, stability and durability are extremely high. Furthermore, by connecting a large number of heat diffusion pairs, it is theoretically possible to obtain an extremely high pressure, with only the strength of the container being the limit. Furthermore, the present invention does not require any special conditions regarding the temperature difference imparted to this heat diffusion pair, making it possible to utilize a wide range of energy sources. can be used and recycled, and the operating costs of the equipment can be kept low.

First, the principle of the heat diffusion pair according to the present invention will be explained using the drawings.

FIG. 1 is a schematic diagram of the principle of a heat diffusion pair according to the present invention, where 1 is a heat diffusion pair, M and N are two different material systems, and a porous material 7 is used for N. .

Thermal diffusion pair 1 consists of two different material systems M and N.
One or both systems use porous materials as the diffusion medium. When using porous materials for both M and N systems, it is necessary to use materials with different properties.

A porous substance is a substance that contains countless pores, and is also called a porous body, porous material, or porous substance. There are binders, polymer materials, fiber bundles, etc. The porous substance used in the present invention needs to have pores with a pore diameter close to or smaller than the mean free path of the diffusing gas molecules, and which are connected to each other.

The purpose of using this porous material as a diffusion medium in one or both systems of M and N is, firstly, when the pore diameter of the porous material is close to or smaller than the mean free path of gas molecules, The gas molecules passing through the porous material constitute a molecular flow or viscous flow, and the physical and chemical properties of the gas molecules in the porous material are significantly different from those in the bulk phase system under normal conditions. This is to create a difference in the physical environment given to the diffusion of gas molecules in the two material systems M and N by utilizing a well-known phenomenon. Second, it is possible to compress the gas by eliminating the increase in transport resistance that occurs when a solid such as a metal film that is permeable to the gas to be transported is used for both the M and N systems. This is to ensure that.

FIG. 1 shows a case where a porous material 7 is used only for N, M remains in a normal gas phase (bulk phase), and M and N are made of two different material systems. The two different material systems M and N are brought into contact with each other at an interface 6 at one end thereof, and a temperature gradient is created in the systems M and N by a high temperature section 8 and a low temperature section 9 and 9', respectively. ing. Here, a temperature gradient may be provided by setting the high temperature section 8 as a low temperature section and setting the low temperature sections 9 and 9' as high temperature sections. The porous material 7 used in the system N needs to have low thermal conductivity to easily maintain a temperature gradient and be chemically stable with respect to the gas used for compression.

In the thermal diffusion pair 1 configured as described above, since a temperature gradient exists in both of the two different material systems M and N, diffusion occurs in the direction of the temperature gradient in both.

Compression of gas by this thermal diffusion couple can be performed not only for a single component gas but also for a multi-component mixed gas, but a single component system will be described here.

Figure 1 is a schematic diagram showing the principle of thermal diffusion pair 1. In system N using porous material 7 as the diffusion medium of thermal diffusion pair 1, the distribution is uniform in the absence of a temperature gradient. However, the high temperature section 8
When a temperature gradient is provided by providing a low temperature section 9', thermal diffusion of gas molecules occurs in the direction of the temperature gradient, and in most cases, gas molecules are transported from the high temperature side to the low temperature side. In rare cases, diffusion in the opposite direction may occur depending on the combination of gas molecules and porous materials. When the uneven distribution of gas molecules occurs due to thermal diffusion, concentration diffusion occurs in the direction that cancels this, and when a certain uneven distribution of gas molecules corresponding to the temperature gradient or a concentration difference is reached, the two eventually become balanced. A steady state is reached at , and the apparent diffusion disappears.

At this time, the chemical potential of the gas molecules at the high temperature side 4 of N is μ ₄ , the corresponding bulk phase pressure is P ₄ , and those at the low temperature side 5 of N are μ ₅ , P ₅
shall be. When there is no temperature gradient, μ ₄ = μ ₅ ,
Although P ₄ =P ₅ , a difference occurs between μ ₄ and μ ₅ due to thermal diffusion due to the temperature difference between the high temperature section 8 and the low temperature section 9'. If the difference in chemical potential is Δμ _N = μ ₅ − μ ₄ , then Δμ _N
is a value specific to the substance and gas molecule used for N.

On the other hand, in the gas phase system (bulk phase) M, the chemical potentials and pressures at the high temperature side 2 of M and the low temperature side 3 of M are respectively μ ₂ , P ₂ , μ ₃ , and P ₃ . When there is no temperature gradient, μ ₂ =μ ₃ and P ₂ =P ₃ . Although "thermal diffusion" is not generally used as a term in single-component systems, movement of gas molecules occurs even in single-component systems if a temperature gradient is applied. Assuming that the high temperature section 8 is spatially at the top and convection can be ignored, in most cases the distance from the high temperature side 2 of M to the low temperature side 3 of M
In a closed system, the gas molecules move toward , and in a closed system, the resulting density difference leads to concentration diffusion and a steady state is reached. In this case as well, Δμ _M = μ ₃ − μ ₂ appears corresponding to the temperature difference between the high temperature part 8 and the low temperature part 9, but (if it is a bulk phase of a single component system, P ₂ = P ₃ is held) ) Δμ _M is a value specific to the gas phase system M.

Now, at the interface 6, gas molecules can be exchanged between the system M and the system N, and the high temperature side 2 of M and N
Since the high temperature side 4 of is at the same temperature, it is clear that μ ₂ =
μ ₄ , so P ₂ =P ₄ . On the other hand, assuming that the low-temperature parts 9 and 9' are at the same temperature on both the low-temperature side 3 of M and the low-temperature side 5 of N, then from the above definition formula, the relationship μ ₅ = μ ₄ +Δμ _N μ ₃ = μ ₂ +Δμ _M It is in. However, Δμ _N and Δμ _M are values specific to the respective diffusion media N and M, and generally Δμ _N ≠
Since Δμ _M , when μ ₄ =μ ₂ due to the exchange of gas molecules at the interface 6, μ ₅ ≠ μ ₃ . This means that P ₅ ≠ P _{3 holds true for P 5 and P 3 corresponding to} μ ₅ and μ ₃ , respectively. In other words, if a separate gas phase system is provided in the low temperature part 9' in contact with the low temperature side 5 of N, the pressure becomes P ₅ due to the exchange of gas molecules with the low temperature side 5 of N, but this is caused by thermal diffusion. This is different from the pressure P ₃ on the low temperature side 3 of M, which faces the pair across the pair. This can be said to be the result of the heat diffusion pair compressing one side and reducing the pressure on the other. It is not limited to the combination of the system N using the porous material 7 and the gas phase system (bulk phase) M of the diffused gas, but as long as it is a combination of substances in which gas molecules can diffuse,
Each provides a unique environment for the diffusion of gas molecules,
Generally, since Δμ _N ≠Δμ _M , P ₅ ≠ P ₃ . However, if N and M are the same substance system, Δμ _N =
Δμ _M , and P ₅ =P ₃ , and the effect of compression and depressurization of gas molecules does not occur. Therefore, when using porous materials for both M and N, materials with different properties must be used. A configuration of a thermal diffusion pair, such as using a metal foil that allows gas molecules to pass through one of M and N, or using a mutually different mixed gas phase system sealed through a selectively permeable membrane for both M and N. However, from the viewpoints of reducing diffusion resistance, simplicity of device configuration, stability, etc., it is preferable to use the bulk gas phase system of diffused gas molecules described above to explain the principle of the present invention. It is thought that the combination with a porous material that meets the certain conditions shown in (a) is the most practical.

The above is an explanation of the principle of a thermal diffusion couple using a porous material from the general viewpoint of mass transfer along a temperature gradient and thermal diffusion. From the viewpoint of phenomena, a more phenomenological explanation is possible. FIG. 2 shows a situation in which single-component gases contained in two containers 31 and 32 are separated by a stopper 34 made of a porous material 33. Gas molecules are permeable through the porous material 33, and one container 31 is brought to a temperature T ₁ of the other container 32.
is maintained at temperature T ₂ such that T ₁ ≠ T ₂ . The gas in the two containers 31 and 32 is in the bulk phase, but if the respective temperatures are maintained for a sufficient period of time, the migration of gas molecules between the two containers through the porous material 33 will reach equilibrium. It stops. At that time, it is known that the pressure P ₁ in one container 31 and the pressure P ₂ in the other container 32 are not the same. If both containers are not made of porous material and are connected by a suitable passage such as a pipe, P ₁ =
It should be P ₂ . This phenomenon through porous materials, permeable membranes, capillaries, etc. is called the Knudsen effect, and the pressure difference that occurs at this time is called thermomolecular pressure.
Pressure) At both ends of the porous material 33 in FIG. 2, that is, near the interfaces 35 and 36 in contact with the gas phase of each container.
The pressure of the gas molecules in the porous material 33 is expressed by the pressure of the gas phase system (bulk phase) that is in equilibrium with it.
Assuming that the pressure at one end 35 is P ₁ ' and the pressure at the other end 36 is P ₂ ', it is clear from the definitions that P ₁ = P ₁ ' and P ₂ = P ₂ '. Therefore, when comparing FIG. 2 with the previous FIG. 1, the plug 34 of the porous material 33 in FIG. 2 corresponds to the diffusion medium N in FIG. 1, and if T ₁ > T ₂ in FIG. , P ₁ ′ corresponds to P ₄ and P ₂ ′ corresponds to P ₅ , so
It can be explained phenomenologically that when a temperature gradient is given in the thermal diffusion pair 1 in Figure 1, P ₄ ≠ P ₅ , and since M is in the bulk phase, the system Since the pressure inside is equal everywhere, P ₂ = P ₃ and there is an exchange of gas molecules through the interface 6,
P ₂ = P ₄ , that is, P ₃ = P ₂ = P ₄ , but since P ₄ ≠ P ₅ as described above due to the Knudsen effect, it is obvious that P ₃ ≠ P ₅ . In this way, the phenomenological results also explain that in a heat diffusion pair using a porous material, there is a difference in pressure between both ends, and a gas molecule transport effect is observed.

In Figure 2, the phenomenon occurs between a gas phase system confined in a container, which is a closed system, but the gas phase system in contact with both ends of the porous material is an open system, and gas molecules are transferred from one side to the other. If no pressure increase or decrease occurs as a result of movement to , a steady flow of gas due to a temperature gradient is observed.

The flow of gas in such a porous material is
Discovered by Feddersen (W.Feddersen,
Pogg.Ann.Physik Chem.(5)148, P.302 (1873)),
He called this phenomenon thermal diffusion, but today the movement of particles due to a temperature gradient in a multi-component system is called thermal diffusion, and the movement of particles due to a temperature gradient in a multi-component system is called thermal diffusion. This is conventionally called thermoosmosis.
Phenomenologically, thermal diffusion begins with a deviation in composition due to a temperature gradient in a component gas phase system. Separately, the diffusion of solutes in a solution due to a temperature gradient is known as the Soret effect, and Diffusion phenomena along the temperature gradient of light element atoms dissolved in solids were also observed, but these were later explained as heat flow due to temperature gradients with the development of thermodynamics of irreversible processes by Onsager et al. It has been understood to this day as a mass transfer associated with Of course, this includes the aforementioned Knudsen effect, but the thermoelectric power (Seebek effect) that makes thermocouples made of two metals used for temperature measurement function is also the movement of electrons accompanying heat flow. This can be understood as a phenomenon related to this.

From a phenomenological point of view, the mass transfer associated with heat flow has been divided into various parts and called by different names due to historical backgrounds, and the relatively comprehensive term "thermal diffusion" does not necessarily cover all phenomena. In this specification, in addition to its conventional meaning, it is also used as a general term for the movement of atoms, molecules, ions, or aggregates of these due to heat flow, that is, temperature gradient.
Uses "thermal diffusion". The name "thermal diffusion couple" was given assuming various material systems for the diffusion media M and N, and therefore it is intentionally applied even when one of M and N is a single component gas phase system. There is. In order to extract the effect of the heat diffusion couple to the outside, the ends of each of the two diffusion media are brought into contact with the systems R and S to be affected, which are the systems on which the heat diffusion couple is to be applied. R and S are a normal gas phase system (bulk phase) with diffusion medium molecules.
The situation is as shown in Figure 3. As in the case of Figure 1, the ends of the diffusion media M and N are
3,45, and the diffused material pressure P ₄₃ there,
Defining P ₄₅ , if gas molecules can be exchanged between the end 43 of M and R and between the end 45 of N and S, the pressure of R, P _R , and the pressure of S, P _S , P ₄₃ =
P _R , R ₄₅ = P _S.

When no temperature gradient is given to the thermal diffusion couple, P _R = P ₄₃ = P ₄₅ = P _S , but when a temperature gradient is given, P ₄₃ ≠ P ₄₅ as shown above, and therefore P _R ≠ P _S. That is, gas molecules are transported from one of R and S to the other.

As a result, if R and S are closed systems,
A steady state is reached with a constant pressure difference remaining between P _R and P _S , and the flow of gas molecules from one side to the other stops. However, if P _R and P _S are open systems, the thermal diffusion couple This action results in a constant flow of gas molecules from one side to the other. In other words, the heat diffusion couple functions as a gas fluid pump by being given a temperature gradient.

As mentioned above, it is possible to compress and reduce the pressure of gas by thermal diffusion, but as explained in Figure 1,
Since the difference between the pressures P ₅ and P ₃ generated at both ends of the base thermal diffusion pair is extremely small, this alone is not practical. However, in the present invention, this effect can be superimposed by connecting a large number of heat diffusion pair substrates. The basis for the heat diffusion pair configuration lies in the fact that this superposition is possible. Next, the superposition of effects due to the connection of this heat diffusion pair will be described.

FIG. 4 shows a state in which two heat diffusion pairs 11 and 21 are connected in series to form a heat diffusion pair array. For both thermal diffusion pairs, in order to match the direction of gas molecule transport, that is, the polarity, one thermal diffusion pair ₁₁ using a porous material and the other thermal diffusion pair substrate 21 using normal gas. _M2 , which is a phase system (bulk phase), is connected at the contact interface 16' so as to enable exchange of gas molecules as a diffusing substance. Even when connecting hundreds or thousands of thermal diffusion pairs, it is necessary to connect the adjacent thermal diffusion pairs with N using a porous material and a normal gas phase system (bulk phase) M to match the polarity. There is. In Figure 4, 18,
28 is a high temperature section, and 19, 29, 29' are low temperature sections, which provide a temperature gradient to M ₁ , N ₁ , M ₂ , and N ₂ . For the sake of simplicity, we consider a one-component system, and as in the case of Fig. 1, we calculate the chemical polarities of the diffused gas molecules at each location,
and _{the corresponding} pressures according _{to the numbers} indicated _{in FIG .
P13} ,
Let P ₁₂ , P ₁₄ , P ₁₅ , P ₂₃ , P ₂₂ , P ₂₄ , P ₂₅ . When there is no temperature gradient, μ ₁₃ = μ ₁₂ = μ ₁₄ = μ _{15 = μ 23} = μ ₂₂ = μ ₂₄ = μ ₂₅ and P ₁₃ = P ₁₂ = P ₁₄ = P ₁₅ = P ₂₃ = _{P 22 =} P ₂₄ = P ₂₅ . When a temperature gradient is given to each diffusion medium by setting 18, 28 as a high temperature part and 19, 29, 29' as a low temperature part,
First, regarding the thermal diffusion pair 21, as in the case of FIG. 1, as a result of the movement of gas molecules caused by the temperature gradient, μ ₂₅ + μ ₂₄ + Δμ _N μ ₂₃ = μ ₂₂ + Δμ _M , and μ ₂₄ = μ ₂₂ becomes.

Although Δμ _N ≠Δμ _M , which one is larger depends on the combination of the diffused gas molecules and the material system used for M and N. Now, if Δμ _M > Δμ _N , then μ ₂₃ > μ ₂₅ , so the corresponding P ₂₃ ,
_{The relationship P 23 >} P ₂₅ holds between P 25, and
μ ₂₃ −μ ₂₅ =Δμ _M −Δμ _N. At this time, regarding the thermal diffusion pair 21, the transport of gas molecules creates a temperature gradient, so that the gas flows from the low temperature side 25 of N ₂ to the high temperature side 24 of _{N 2 and} the high temperature side 22 of M ₂ . This means that the attack was made towards side 23.

On the other hand, regarding the thermal diffusion pair 11, the following relationships also hold: μ ₁₅ = μ ₁₄ +Δμ _N μ ₁₃ = μ ₁₂ +Δμ _M and μ ₁₄ = μ ₁₂ , and the polarity is the same as that of the thermal diffusion pair 21, so μ ₁₃ −μ ₁₅ = Δμ _M −Δμ _N > 0, and the transition of gas molecules is from the low temperature side 15 of N ₁ .
It reaches the low temperature side 13 of M ₁ via the high temperature side 14 of N ₁ and the high temperature side 12 of M ₁ , so that P ₁₃ >P ₁₅ . However, since the diffusion gas molecules are exchanged between the two thermal diffusion pairs 11 and 21 at the contact interface 16', μ ₁₅ =μ ₂₃ is always maintained. In other words, in the heat diffusion pair 21, the M ₂ low temperature side 2 is lower than the N ₂ low temperature side 25.
The gas molecules transported to 3 are N ₁ of thermal diffusion couple 11
When the concentration of gas molecules at the low temperature side 15 of the thermal diffusion pair 11 decreases due to transport from the low temperature side 15 of N ₁ toward the low temperature side 13 of M ₁ , the concentration of gas molecules decreases from the low temperature side 23 of M ₂ to the low temperature side 15 of N ₁ . The gas molecules transferred to the low temperature side 15 of _N1 are further transported to the low temperature side 13 of _M1 . This is done until the entire heat diffusion pair reaches steady state.

As a result, the difference in chemical potential at both ends of the thermal diffusion pair is: μ ₁₅ = μ ₂₃ , so μ ₁₃ − μ ₂₅ = (μ ₁₃ − μ ₁₅ ) + (μ ₁₅ − μ ₂₅ ) = (μ ₁₃ − μ ₁₅ )+(μ ₂₃ −μ ₂₅ )=2(Δμ _M −Δμ _N )>0, which is twice the chemical potential difference between the two ends in the case of thermal diffusion versus one substrate. Also, μ ₁₃ > μ ₁₅ = μ ₂₃ >
Since μ ₂₅ , the corresponding pressure is also P ₁₃ > P ₁₅ = P ₂₃ >
P ₂₅ , the value compressed by the thermal diffusion pair,
It will be larger than P ₂₃ . In order to quantify this more easily, if we approximate the relationship between gas pressure and chemical porosity using an ideal gas model, we get 19,2
If the absolute temperature of the low-temperature part of 9, 29' is T, then in the thermal diffusion pair 21, μ ₂₅ = RTln P ₂₅ , μ ₂₃ =
From RTln P ₂₃ , μ ₂₃ − μ ₂₅ = Δμ _M − Δμ _N = RTln
P ₂₃ /P ₂₅ holds true. However, R is a gas constant.

If the compressibility k of the thermal diffusion pair 21 is expressed as k=P ₂₃ /P ₂₅ , similarly for the thermal diffusion pair 11, μ ₁₃ − μ ₁₅ = Δμ _M −Δμ _N = μ ₂₃ − μ ₂₅ , so μ ₁₃ −μ ₁₅ = RTln P ₁₃ /P ₁₅ = RTln P ₂₃ /P ₂₅ , and P ₁₃ /P ₁₅ = P ₂₃ /P ₂₅ = k On the other hand, since P ₁₅ = P ₂₃ , therefore, the thermal diffusion pair The pressure of , the ratio of P ₁₃ and P ₂₅ is P ₁₃ /P ₂₅ = P ₁₃ /P ₁₅・P ₁₅ /P ₂₅ =P ₁₃ /P ₁₅・P ₂₃ /
P ₂₅ = k ² .

When the number of connected groups of thermal diffusion pairs is further increased, the effects are similarly superimposed, and when n groups are connected, the chemical potential difference of the diffusing gas molecules at both ends is n times that of the case of one thermal diffusion pair, and Correspondingly, the compression ratio will be k ⁿ .

Figure 5 is an explanatory diagram showing a state in which thermal diffusion pairs are connected in series, where N, N, N, N are systems using porous materials as diffusion media, and M, M, M, M are diffusion pairs. It is a normal gas phase system (bulk phase) consisting of the same components as gas molecules. 8, 8, 8, 8 are high temperature parts,
9, 9, 9, 9, 9' are considered low temperature parts. By matching the polarities of the heat diffusion pairs and connecting them in series in this way, the effect of compression or depressurization of the gas can be achieved by diffusion due to the temperature gradient, as explained in connection of two heat diffusion pairs using Figure 4. The superposition of will be performed. Here, the term "high temperature part" or "low temperature part" refers to the relative relationship between the two, and does not indicate high temperature or low temperature in a general sense, such as 1000° C. or higher, 0° C. or lower, or around the temperature of liquid nitrogen.

Also, contrary to the above explanation regarding Figure 5,
8, 8, 8, 8 is the low temperature part, 9, 9, 9, 9,
9' may be used as a high temperature section to provide a temperature gradient. In this case, the polarity of the heat diffusion pair is reversed. The superimposed effect can be obtained even if the high-temperature part and the low-temperature part for each heat diffusion pair are not all at the same temperature. Furthermore, regarding the temperature difference between the high temperature part and the low temperature part, the larger the temperature difference, the greater the effect per thermal diffusion pair, but even if the temperature difference is small, increasing the number of connected groups will increase the effect. It can be used for temperature differences ranging from a few degrees to several hundred degrees or more. When the gas molecules diffusing in the thermal diffusion pair are not a single component, there is a superposition effect on the partial pressure of each component,
Therefore, there is also a superposition effect on the total pressure of the gas phase system. For example, a thermal diffusion pair using air as the diffusion material is also possible. Phenomenologically, when a temperature gradient is applied to a porous material, air flow occurs, as described by the aforementioned Feddersen and Lippmann (G. Lippmann,
Confirmed by Compt.Rend.145, P.105 (1907). The polarity of the thermal diffusion pair, that is, whether the transport of gas molecules shifts from the right side to the left side in Figure 5, or vice versa, is determined by the difference between the gas molecules serving as the diffusing substance and the porous substance used, as well as Figure 4.
It is determined by the combination of which of 8, 8, 8, 8 and 9, 9, 9, 9, 9' should be on the high temperature side. According to Feddersen's report, when a temperature gradient was applied to a porous material, a gas flow always occurred from the low temperature side to the high temperature side. When 8 and 8 are set to the high temperature side and 9, 9, 9, 9, and 9' are set to the low temperature side, transport of gas molecules occurs from the right side to the left side. However, factors that affect the diffusion environment of gas molecules in porous materials include molecular flow,
In addition to the formation of viscous flow, there are problems such as adsorption of gas molecules with the pore walls, interactions between diffused gas molecules when the diffusing substance is two or more components, and depending on the combination, the polarity may be reversed. It seems that there is no gender at all.

In addition, in this specification, the diffusion substance is a gas molecule at the temperature at which the thermal diffusion pair acts;
This means that the bulk phase of the components of the diffusive substance under pressure is a gas phase system, and it is not clear what state the diffusing substance molecules are actually in within the porous material, that is, whether they are adsorbed on the pore walls or not. It does not ask whether there is condensation inside the hole. On the other hand, when dealing with a diffusive substance component whose temperature range in which the thermal diffusion pair acts is below its critical temperature, as compression progresses, the diffusing gas molecules diffuse into the bulk phase side of the thermal diffusion pair. There is also the risk of liquefaction in the medium, and although in this case the thermal diffusion pair still functions in terms of providing the driving force for transport, the diffusion resistance increases and the flow rate decreases.
In such cases, the temperature of the low temperature part of the heat diffusion pair is raised. The above is the principle of heat diffusion pairs and the principle of superimposition of effects by heat diffusion pairs.

Next, a specific example of the thermal diffusion pair according to the present invention will be explained using the drawings.

FIG. 6 shows a side sectional view of a flat heat diffusion pair 51 that is a flat heat diffusion pair.

The flat heat diffusion pair 51 consists of an upper plate 51a provided with an upper blocking wall 53, a lower plate 51b provided with a lower blocking wall 53', and side plates 52, 52. and N using a porous material are alternately used. Gas phase system M is
The reason for this is that the movement of diffused gas has greater resistance in a porous material than in a gas phase system, so by increasing the cross section of N diffusion using a porous material, a flat thermal This is to increase the diffusion speed of the diffusion pair array 51 as a whole. A temperature gradient is given to the flat heat diffusion pair 51 by setting the upper plate 51a on the high temperature side and the lower plate 51b on the low temperature side. Further, gas phase affected systems R and S are provided at both ends of the heat diffusion pair 51.

Porous materials used for N as a diffusion medium include ceramics such as ceramics, glass, and refractory cement, as well as sintered metal materials, polymer materials, fiber bundles, and the like. A condition required for these porous materials is that they have pores connected to each other with a pore diameter close to or smaller than the mean free path of the diffusing gas.

The system N using a porous material and the gas phase system M are arranged so that the exchange of diffused gas is carried out only at the contact surfaces 54, 54' by the upper blocking wall 53 and the lower blocking wall 53'. Here, especially the blocking walls 53, 5
3' may be omitted and the pores on the side surfaces of the porous material are closed so that the exchange of the diffused gas takes place only at the contact surfaces 54, 54'.

FIG. 7 shows the flat heat diffusion pair 51 shown in FIG.
are stacked in 6 rows in the thickness direction as one unit element,
FIG. 7 is a plan cross-sectional view showing a flat thermal diffusion pair plate 55 in which the affected systems R and S are connected in parallel. The affected systems R and S are provided with intake and exhaust ports 56 and 57 for connecting them to the heat diffusion parallel plates 55 S and R of the next stage and for taking out compressed gas.

FIG. 6 shows six heat diffusion pairs connected in series, and FIG. 7 shows six rows of flat heat diffusion pairs 5.
Although one affected system R and S are shown in common and connected in parallel, the number of these can be increased or decreased as appropriate.

FIG. 8 shows a cross-sectional view of a tubular heat diffusion pair 61 in which heat diffusion pairs are arranged in a tubular shape. This tubular heat diffusion pair 61 consists of an inner tube 62 provided with a concentric inner blocking wall 63 and an outer tube 65 provided with an outer blocking wall 63'.
As with the flat heat diffusion pair 51, the square-shaped gas phase system M and the N using a porous material are alternately arranged. Then, hot water or hot air is passed inside the inner tube 62 to form a high temperature part,
The outside of the outer tube 65 is air-cooled, water-cooled, or moistened and left in the atmosphere to form a low-temperature part, thereby providing a temperature gradient to the tubular heat diffusion pair 61.

Alternatively, depending on the situation, the outside may be heated and cold water passed inside. Heat flow occurs radially from the inside of the pipe to the outside, or vice versa. All heat flow occurs through thermal diffusion pairs,
High thermal efficiency can be expected. The cross-sectional shape is simplest to be circular and is advantageous in handling during design, but it may also be circular or square. The diameter of the pipe is appropriately determined based on the number of connections, the size of the porous material used for one heat diffusion pair, etc. The wall thickness of the pipe corresponds to the thickness of the flat plate described above. geothermal heat, seawater temperature difference,
This type of system is extremely effective in converting factory waste heat into resources, as it is only necessary to pass hot or cold water through the pipes. Since there are no particular restrictions on the form of the heat supply source, in special cases there may be a configuration in which a heating wire is passed inside the pipe.

Next, the number of connections of these heat diffusion pairs and the flow rate will be roughly estimated. Phenomenologically, the magnitude of thermal diffusion is expressed by the concentration difference that causes the opposite concentration diffusion even in a steady state. For the medium of diffusion, σ (Soret Coefficient),
When the concentration of a diffusing substance is C (volume molar concentration mol/vol.), the relationship 1/Cgrap C=σ grad T... holds for the temperature gradient and concentration gradient, respectively, and thermal diffusion with σ Use this as a guideline for the size of. In the case of gaseous systems, α≡
Thermal diffusion constant defined by σT
diffusion factor) is mainly used. In actual measurements, values of 0.1 to 1.0 are reported for σ, and σ
A rough estimate can be made as approximately 10 ^-3 (K ^-1 ) at around room temperature. This is the pressure ratio between the high temperature side and the low temperature side when the temperature gradient is ΔT degrees (1 + ΔT × 10 ^-3 )
give. The pressure ratio appearing at both ends of the thermal diffusion couple, i.e. between 2 and 3 in Figure 1 or between R and S in Figure 2, is the ratio of the pressure differences caused by each of the two diffusion media. Although it is defined by the difference, this value can be used for ordering.
If the compression ratio of thermal diffusion to one unit is k, then a compression ratio of k ⁿ can be obtained by connecting n units of thermal diffusion pairs in series. When σ = 10 ^-3 , if the temperature difference is 50 degrees, then k = 1.05, and in order to change one atmosphere of gas to two atmospheres, (1.05) ¹⁶ = ~ 2.18, we need to connect at most 16 groups. It takes.

Now, regarding the flow rate, when the formula holds,
The material flow due to the temperature gradient and the material flow due to the temperature gradient (pressure gradient) cancel each other out, so that the apparent material flow is zero. Therefore, when the concentration gradient is 0, it can be assumed that a material flow of the same size as the material flow due to concentration diffusion at steady state is generated due to the temperature gradient, and the problem of material flow due to thermal diffusion can be replaced with the treatment using concentration diffusion. is possible. The thermal diffusion pair is the affected system R, S
If R and S are each closed systems, the material flow in the opposite direction due to the pressure difference between R and S will eventually cancel out the action of the thermal diffusion pair, resulting in an equilibrium state. However, immediately after the action starts, or when both R and S are open systems and there is no pressure difference between R and S, a material flow occurs in one direction due to thermal diffusion pairs, and an approximate estimate of this flow rate is This is useful when considering the design and economic efficiency of heat diffusion pairs.

A flat thermal diffusion pair as shown in FIG. 6 will be considered as a model. When a porous material is used as the diffusion medium for only one of the heat diffusion pairs, diffusion in the porous material becomes the rate-determining process for the material flow in the heat diffusion pair.
Only diffusion in porous materials is concerned. thickness l,
Flow rate in the thickness direction of a porous plate with area A and porosity (F)
is given by F=DA・ΔC/l, where D is the diffusion coefficient and ΔC is the concentration difference on both sides of the plate. The diffusion coefficient of gas is approximately D _B = ~0.1 cm ² /sec in normal gas systems at normal pressure, but in porous materials, when the pore diameter is larger than the mean free path λ of the gas, D D _B , but if it is less than that, the gas flow forms a Knudsen flow or a molecular flow, and if the pore diameter is d, then D=d/λD _B. When there is a temperature difference ΔT on both sides of the plate and no concentration difference,
According to the above-mentioned idea, when AC/C=σΔT is substituted into, the material flow due to the temperature difference becomes F=d/λD _B・A・C.σ.ΔT/l (mol/sec)... As an example, the pore diameter is ~400 Å (d/λ is ~0.5 for one atmosphere), D _B =0.1 cm ² /sec, =0.5,
A=10cm ² , l=0.5mm, σ=10 ^-3 K ^-1 , ΔT=
Calculating the case of 50 degrees, we get F = ~1.1 x 10 ^-5 mol/sec = 0.25 ml/sec = ~15 ml/min (standard state) near normal temperature and normal pressure. When the same heat diffusion pairs are connected in series, the driving force for transport increases, but the amount of porous material that must pass through increases accordingly, so the flow rate does not change. When connected in parallel, the flow rate increases because it is the same as increasing A.

The above is a rough estimate of the number of connected heat diffusion pairs and the flow rate.

Next, embodiments of the thermal diffusion pair according to the present invention will be described using the drawings.

The function of transferring gas molecules in a thermal diffusion pair from one system to the other can be performed by compressors, ventilators,
It can be used as a blower or vacuum pump, and can be applied to equipment and processes that require these.

This specification describes an air pressure source for an air engine or fluid element circuit that has higher compression than a ventilator or blower, and a power generation device that converts the mechanical energy of compressed gas into electrical energy.

FIG. 9 shows the case where it is used as an air pressure source.
In the figure, reference numerals 72a, 72b, and 72c are the aforementioned flat or tubular heat diffusion pairs, and these heat diffusion pairs 72a, 72b, and 72c are connected in series for superimposition of heat diffusion. A filter 71 is provided on the atmosphere side of the first heat diffusion pair 72a to prevent the pores of the porous material from being clogged by dust in the atmosphere. Further, a check valve 73 is provided on the air tank 74 side of the third stage heat diffusion pair 72c, and is connected to the air tank 74 through this check valve 73. In Figure 9,
Although the heat diffusion pairs 72a, 72b, and 72c described above are connected in series and arranged in four rows in parallel, the number can be changed as appropriate. In addition, the porous material used for the heat diffusion pairs 72a, 72b, and 72c has different pressures between the first heat diffusion pair 72a and the third heat diffusion pair 72c, and as the compression progresses, the mean freedom of gas molecules increases. The journey will be shorter. Therefore, porous materials with different pore diameters are used for each stage in order to find the optimal conditions. The compressed air stored in the air tank 74 is connected to the piping system via a control valve 75.

When used as an air pressure source, usually 4-7Kg/cm ²
However, in this embodiment, a double compression ratio can be obtained with a single heat diffusion pair. In addition, various low-quality energy can be used and recycled as a heat source, but here, factory waste hot water is used as a high-temperature heat source, cold water is used as a low-temperature heat source, and each heat diffusion pair has 72a, 72b,
72c is designed to provide a temperature gradient of approximately 50 degrees. This temperature gradient of 50 degrees causes thermal diffusion as detailed in the principle section, and due to the superposition effect of the thermal diffusion pairs, the first thermal diffusion pair 72a has a pressure of 2 atmospheres, and the second thermal diffusion pair 72b has a pressure of 2 atmospheres. 4 atmospheres, third stage heat diffusion pair 72c
You can get 8 atmospheres of compressed air.

FIG. 10 shows a case where power generation is performed using compressed air by heat diffusion pairs.

In this case, as in the case of the air pressure source explained using FIG. 9, the air passing through the filter 81 is transferred to the first heat diffusion pair 82a, the second heat diffusion pair 82b, . . .
It is superimposed and compressed with the final stage heat diffusion pair 82z to rotate the turbine 83. In this way, a large number of series-connected multi-stage heat diffusion pairs are connected in parallel to increase the air force and the amount of air being blown.

The porous materials used for the heat diffusion pairs 82a, 82b, . However, regarding the strength of porous materials, the pressure increases as you go to the final heat diffusion pair, but the pressure difference applied to one heat diffusion pair is 1
Since the value is only a small value depending on the compressibility of the base thermal diffusion couple, there is no need to give much consideration to the conditions for the strength of the porous material.

Regarding the heat source used, if the heat source is low-quality thermal energy below 100℃, the steam engine cycle used for normal thermal power generation cannot be used. However, in the power generation using the heat diffusion pair of the present invention, there is a wide range of energy that can be used, and low-quality energy sources can be used and recycled. ,
50 for each heat diffusion pair 82a, 82b, ..., 82z
It is designed to provide a temperature gradient of degrees. This 50
The thermal diffusion described in the principle section occurs due to the temperature gradient of 1.5°C, and the superimposed effect of the thermal diffusion pairs compresses the atmosphere and feeds it into the turbine, which exchanges the work caused by the adiabatic expansion of the air into electrical energy. It's summery. Further, in FIG. 10, the air that rotates the turbine is discharged into the atmosphere, but it may be connected to the inlet of the first stage heat diffusion pair in a closed circulation system. At this time, a gas other than air may be used as the diffusing substance.

Next, the number of heat diffusion pairs, heat loss, etc. required for power generation using an air pressure source and compressed air will be described. When used as an air pressure source, in order to double the compression ratio of each stage in Fig. 9, if the conditions are the same as in the previous case and a compression ratio of k = 1.05 is obtained for each stage, (1.05) ¹⁶ = ~2.2, it is necessary to prepare heat diffusion pairs with approximately 16 series connections for each stage. However, if 16 units are used in one stage, three stages will result in 10 times the compression, including the fraction. 10 m ³ /
In order to obtain a compressed air flow rate of min, a diffusion cross section of approximately 670 m ² is required for each heat diffusion pair, as calculated backwards from the above equation. Therefore, in order to maintain this air volume, a diffusion cross section of 670 x 16 = 10,720 for each stage, totaling about 32,000 m ² in total for the three stages, is required.

If we prepare a large number of flat heat diffusion pair plates as shown in Fig. 7, connect them in series or parallel as appropriate, and obtain the number of serially connected bases and the diffusion cross section per unit that meet these conditions, Even if the porous material occupies most of the area of the plate and the rest is ignored, when the size of one flat heat diffusion pair plate is 1 m square,
32,000 flat heat-diffusing parallel plates must be prepared. If we were to create a design in which a large number of flat heat-diffusing parallel plates were arranged in tandem at regular intervals, hot water and cold water would flow alternately between the plates, and the space occupied by the heat-diffusing parallel plates would be reduced. , l=
A 0.5 mm porous plate is sandwiched between two metal plates of the same thickness to make the heat diffusion pair plate less than 2 mm thick.
Assuming that 200 plates are arranged vertically in 1 m, 160 ^m3 of air will be used for 32,000 plates, which corresponds to occupying a space of ~5.4 m square, but in reality it is necessary to maintain the strength of the water supply piping + structure. Adds more space. The 32,000 heat-diffusing array plates are divided into three groups, each of which is used for the first, second, and third stage heat-diffusing arrays in Figure 9.As compression progresses, each stage A porous material is chosen so that the pore size is small. According to classical theory, the mean free path of a gas is inversely proportional to the gas density, so near normal pressure,
Since the mean free path λ of O ₂ and N ₂ are both about 700 to 800 Å, the pore diameter of the porous material is d = 400 Å for the first stage, d = 200 Å for the second stage, and d = 100 Å for the third stage. , d/λ is 1/2, 1/4, 1/8,
However, in the formula showing the flow rate, as compression progresses, d/λ decreases, but the gas density C increases due to compression, and the flow rate is proportional to both, so the flow rate at each stage does not change. . The air volume mentioned above is under standard conditions, and if the air is at 10 atmospheres, it will be 1 m ³ /min.

In FIG. 9, when there is no check valve 73, air tank 74, etc. in the flow path from the third stage heat diffusion pair 72C to the check valve 73 and air tank 74, and the flow path is then opened to the air. The device has a maximum of ~10
Supply compressed air up to Kg/ ^cm2 , ^10m3 /min at normal pressure
It works as a blower with an air volume of . When used as an air pressure source, it is better to provide an air tank 74 midway as shown in Figure 9 than to connect it directly to the piping system, as it allows compressed air to be stored even when not in operation.
It can compensate for the lack of air volume. At the above air volume, ~
It can accumulate ^1440m3 of compressed air at 10 atm per day.
The above-mentioned air flow rate is at the initial stage of accumulation, and as the accumulated air pressure is opposed and the pressure within the air tank 74 increases, the flow rate decreases. It is sufficient to estimate about half of this value. It is technically possible to construct an air storage tank of this size.

In the case of power generation using compressed air as shown in Fig. 10, the compression ratio should be determined based on the turbine design, efficiency, etc., but in the case of a steam turbine, it is several tens to hundreds of kg/ Driving in cm ² .
There are turbines that can be operated at pressures of at most several kg/cm ² , and it is possible to create compressed air to that extent using heat diffusion pairs. Continuous operation at 10 atm, same flow rate as for the previous pneumatic source, 10 m ³ /min
Let's calculate the power generation capacity etc. assuming that (standard state) is given. A turbine rotates by being given work by adiabatic expansion of compressed gas at 10 atm to normal pressure, but if compressed gas at 10 atm and 70°C is continuously supplied at 1 m ³ /min, it can be approximated by an ideal gas. Assuming that the insulation coefficient of air is γ = 1.4, the amount of work is 370 kcal/min, approximately 26 kw. Of this, 50% goes to the rotational power of the turbine.
Assuming that the efficiency from the turbine to the generator is 90%, approximately 12kW of power will be generated. For this purpose, the compression ratio of one heat diffusion pair is set to 1.05 as in the above case, and 64 pairs are connected in series. As a result, gas at one atmosphere can be compressed to (1.05) ⁶⁴ = ~23 (atm) in the final state, but if the compression progresses to this point, the flow rate will be zero, but if the compression state is about 10 atm, The above operating conditions are satisfied by leaving a transport driving force equivalent to the difference of about 10 atmospheres. In this case, the total diffusion area of the heat diffusion pairs required is 4/3 times that of the previous pneumatic source, and a large number of flat heat diffusion pairs used in the case of the pneumatic source are densely arranged in tandem. If designed to do so, the heat diffusion pairs will occupy a space of ~6m square.

As for heat loss, if we consider a flat heat diffusion pair plate as a model, the heat flow q per unit area in the plate thickness direction due to the temperature difference ΔT on both sides of the plate is expressed as q=ρΔT/ using thermal conductivity ρ. It can be expressed as l. Porous materials contain many pores, and p is generally 0.1 to 0.01 kcal/m, which is about the same as that of a normal gas phase system.
Takes the value of hr.deg. Therefore, the value of air at room temperature ρ
=0.02kcal/m. Take hr.deg and consider it as the value of the porous material used, assuming a temperature difference of 50 degrees and a plate thickness of the porous material l = 0.5 mm, ignoring the temperature gradient within the metal plate of the outer frame that sandwiches the porous material. However, roughly speaking, in the case of the air pressure source mentioned above, the heat consumption is approximately 1,070,000 kcal/min. As a heat source, consider a water flow at room temperature of 20℃ with a sufficient flow rate on the low temperature side of the heat diffusion pair, and a hot water flow at 90℃ as the heat source on the high temperature side. Assuming that the temperature on the hot water side drops to 50°C and is discharged from the equipment, and it continues to provide an average temperature difference of 50°C, in order to supply the above amount of heat, a flow rate of ~27m ³ /min is required. Hot water must be continuously supplied.

In the case of power generation using compressed air as shown in Figure 10, for a similar heat source, hot water at 90°C ~ 35m ³ /
It requires a supply of 1.4 million kcal/min and consumes approximately 1.4 million kcal/min of thermal energy. Compared to the 12kw power generation mentioned above, the efficiency is ~0.01%. Although this value is not necessarily satisfactory, it is quite possible to further increase this value through detailed and rational adjustments in the design, and based on the calculation assumptions above, this value Therefore, even if the temperature of the hot water serving as the heat source is low and the temperature difference between the high temperature side and the low temperature side of the heat diffusion pair is 1 degree, the same efficiency will be provided.

Although the above calculated values are only rough estimates, the various assumptions introduced in the calculation process are based on physical,
It is chemically acceptable and can be used as a sufficient first approximation. Although it is not easy to accurately know the magnitude of the effect, as long as a thermal diffusion pair is constructed that satisfies the requirements described in this specification, the gas molecule transport compression and its superimposition effects that are the object of the present invention will definitely exist. do.

As described above, the gas transport and compression device using the heat diffusion couple of the present invention does not require any mechanical equipment, so there is no noise or vibration, and since it does not require lubricating oil, the compressed gas is supplied with lubricating oil. There is no contamination. Furthermore, since there are no special conditions regarding the temperature difference given to this heat diffusion couple, it is possible to use a wide range of energy sources. It is possible to reduce the operating cost of the gas transportation and compression device free of charge or at low cost.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the principle of the heat diffusion couple according to the present invention, Figure 2 is an explanatory diagram of the conventionally known Knudsen effect, and Figure 3 is the system R, S affected by heat diffusion according to the present invention. FIG. 4 is a schematic principle diagram illustrating the superposition of effects due to a heat diffusion pair array in which two heat diffusion pairs according to the present invention are connected in series, and FIG. 5 is a diagram showing the state in which the present invention is connected. FIG. 6 is a side sectional view of a flat heat diffusion pair according to the present invention, and FIG. 7 is a flat heat diffusion pair plate according to the present invention. 8 is a sectional view of a tubular heat diffusion pair according to the present invention, and FIG. 9 is a conceptual diagram showing an air pressure source as an embodiment of the present invention.
FIG. 10 is a conceptual diagram showing a power generation device according to another embodiment of the present invention. 1, 11, 21...Thermal diffusion couple, M, M ₁ , M ₂ ... Ordinary gas phase system (bulk phase), N, N ₁ , N ₂ ... System using porous material as a diffusion medium, 7, 17 ,2
7,33...Porous material, 8,18,28...High temperature part, 9,9',19,29,29'...Low temperature part, R,
S... Acted system, 51... Flat heat diffusion pair, 55... Flat heat diffusion pair plate, 61... Tubular heat diffusion pair.

Claims (1)

[Scope of Claims] 1 Two material systems M and N that are in contact with each other so as to be able to exchange diffused gas molecules are constituted, and at least one of these material systems M and N has a material in the vicinity of the mean free path of the diffused gas molecules or A porous material having pores connected with each other with a pore diameter smaller than that is used, and one end where the two material systems M and N are in contact is set to a high or low temperature, and the other end is set to a low or high temperature to form a heat diffusion pair. A gas transport compression device using a porous material, characterized in that: 2 Construct two material systems M and N that are in contact with each other so that the diffused gas molecules can be exchanged, and at least one of these material systems M and N has pores with a pore diameter near or smaller than the mean free path of the diffused gas molecules. A porous material with connected pores is used to create a heat diffusion pair by creating a temperature gradient between one end and the other end where two material systems contact each other, and a large number of these heat diffusion pairs are connected. 1. A gas transport and compression device using a porous material, which comprises a heat diffusion pair and is provided with gas phase affected systems R and S at both ends of the heat diffusion pair.