JPS6032799B2 - Energy concentration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an energy concentrating method, and particularly to an energy concentrating method in which low-temperature 9E heat, which has not been available until now, is condensed, that is, converted into high-temperature heat and effectively used.

As a result of the recent oil crisis, frequent occurrences of heat pollution, and energy outlook, there is an increasing need to consider effective methods for recovering large amounts of low-temperature heat, which had been wasted until now, from all directions.

Although there are currently no heat recovery devices that have been put into practical use, the nitric acid circulation process can be cited as one that is at the laboratory level.

The nitric acid circulation process utilizes the heat generated by mixing and diluting concentrated nitric acid and water, and also separates this mixture by low-temperature vacuum distillation and reuses it. Nitric acid and water are the highest azeotropic mixture. It applies the fact that it can be separated using low-temperature thermal energy. In Figure 1,
In the nitric acid process, using hot water of 28℃ (acceptable if it is above 2.0℃) and cold water of 7℃ (acceptable if it is below 9.700),
This shows a multi-stage system that converts heat around 0:00 to 0:00 and can be recovered and used.

1-1 to 1-4 are distillation columns for separating an aqueous nitric acid solution into water vapor and concentrated nitric acid under low pressure using low-temperature heat; 2-1 to 2-
4 is a condenser that converts water vapor into water using cold water, 3-1 to 3-8
is a preheater that heats the generated water and concentrated nitric acid with hot water, 4-
1 to 4 - 4 is a mixing tank that mixes water and concentrated nitric acid and generates heat; 5
11 to 5-3 are heat exchangers that use the heat obtained to raise the temperature of water and concentrated nitric acid produced from another system, and 5-4 is a heat exchanger that supplies the heat obtained in the final process to the consumer side. It is.

The nitric acid aqueous solution is distilled under reduced pressure in the distillation column 1-1 to a concentration of approximately 6.
It is separated into a 5% azeotropic mixture (concentrated nitric acid) and a vapor containing nitric acid with a concentration lower than 1%, the vapor is liquefied in the condenser 2-1, and both liquids are liquefied in the fermenters 3-1 and 3-2. After the temperature is raised, dilution heat is generated in the mixing tank 4-1. Further, concentrated nitric acid and water produced in the distillation column 1-2 and obtained through a similar process are heated in the heat exchanger 5-1 using the heat obtained in the mixing tank 4-1. After raising the temperature, it is mixed in the mixing tank 4-2 to generate heat, and this heat is used for raising the temperature again to create a multi-stage process.
It is an attempt to obtain high temperature heat around 00OO. The nitric acid circulation process is vacuum distillation, which has a small temperature rise in a single stage, but uses multi-stage flash evaporation, which is complex and large-scale.In addition, nitric acid itself is a powerful chemical, corrosive, and harmful, and requires energy recovery. The experimental efficiency is as low as about 4%.

Therefore, the present inventors have developed a field in which energy provided in the form of heat from power plants, factories, etc. and natural energy can be stored and, if possible, condensed (i.e. at high temperature) and used effectively. As a result of intensive research on supply methods,
The method of the present invention has been achieved.

That is, the present invention applies heat from a low-temperature heat source to the first reversible reactant to decompose it to release gas, pressurizes this gas, and then reacts with the first reversible reactant after releasing the gas. by extracting heat at a higher temperature than the heat source, and subsequently applying this heat to a second reversible reactant having a higher reaction temperature than the first reversible reactant to decompose it, thereby releasing gas. The present invention relates to an energy concentrating method characterized in that, after the gas is pressurized, the gas is reacted and combined with a second reversible reactant from which the gas has been released, thereby extracting higher-temperature heat.

In the method of the present invention, the first reversible reactant is a substance that decomposes to generate gas when heated in a low temperature region, and generates heat when combined with the gas (hereinafter referred to as a low temperature reversible reactant). ), and the second reversible reactant is a substance that acts in the same way as the above in a high temperature region (hereinafter referred to as a high temperature reversible reactant), and all of the substances have a positive slope of the equilibrium decomposition pressure curve. It is. Hereinafter, the method of the present invention will be explained in detail using the accompanying drawings and the like.

FIG. 2 is a flow sheet showing one embodiment of the method of the present invention.

In addition, in FIG. 2, a case will be explained in which a metal hydride, which will be described later, is used as a low-temperature to high-temperature reversible reactant. In FIG. 2, 6 is a heat source provided to the device, 7 is a heat exchange pipe on the heat source side, 8 is a thermal butterfly (pline) circulation pipe,
9-1 is a hydrogenation reactor containing metal hydride or metal (first stage), 9-2 is the same (second stage), ... 9-n is the same (
nth stage), 10- is a heat exchange pipe in the first stage hydrogenation reactor, 10n is a heat exchange pipe in the nth stage hydrogenation reactor, 11-1 is a heat medium flow rate adjustment on the heat source side valve, 11
12 is a valve for adjusting the flow rate of hot soot between the 1st and 2nd stages...
11-n is (n-1), a valve for adjusting the flow rate of heat medium between n stages;
11-n11 is a consumption side heat medium flow rate adjustment valve, 12-1
is the hydrogen gas flow rate adjustment valve (first stage),...
12-n is the same (nth stage), 13 is the consumer heated object, 14
is the consumption side heat exchange pipe.

First, it is assumed that the heat source 6 is provided and the reactor 9-1 contains a hydride of metal M.

Heat exchange pipes 7 and 10-1 are closed by closing valves 11-2 and opening valves 11-1 to circulate hot soot.
Heat is provided to reactor 9-1 through. Heat is in reactor 9
-Hydrogen separation pressure P, L constant for temperature T, L within 1
, and the hydrogen with these pressures P and L is passed through the hydrogen valve 12-
1 and stored in a separate container V, (not shown). When the supply of the heat source 6 is finished, the hydrogen in the container V is transferred to P,
By supplying reactor 9-1 with a higher pressure and temperature P than L, metal M, re-reacts with this hydrogen and reactor 9-1
The temperature of −1 is the temperature T river higher than T and L. Next, the valves 11-1 and 11-3 are closed, the valves 11-2 are opened, and the hot soot is circulated to transfer the heat of the temperature T to the reactor 9 through the heat exchange pipes 10-1 and 10-2. −
You can move from 1 to 9-2. Reactor 9-2
At the beginning, a metal M2 different from the metal M in the reactor 9-1 is
Assuming that there is a hydride in the container, the heat given will cause the temperature LL=T and the pressure P. Hydrogen L is released from the metal hydride and is stored in a separate container V2 (not shown) by opening the hydrogen valve 12-2. The same operation is repeated to convert low-temperature heat into high-temperature heat, and when the required temperature is reached, it is passed through the consumer-side heat exchange pipe 14 to the consumer-side heated object 1.
It gives heat to 3. The hydrogenation and hydrogen decomposition reactions of metal hydrides depend only on temperature and hydrogen pressure, and are shown in a PCT diagram (showing the relationship between equilibrium pressure, hydride component ratio, and temperature) as shown in Figure 3. Many of them have the following characteristics (in FIG. 3, the relationship of temperature T is L>T2>T). Fourth
The figure is a blot of the relationship between equilibrium pressure and temperature for a number of metal hydrides.In principle, if multiple metals are used, thermal energy can be converted into temperature within a range of approximately 120 to 950 degrees Celsius. It shows that.

In addition, in Figure 4, graph 1 is Ca ratio, graph 2 is LiH
, graph 3 is Tj mountain, graph 4 is NaH graph QMg ratio, graph 6 is M saddle NiH4 (hydride of magnesium-nickel alloy), graph 7 is Mg2C cape g3 (hydride of magnesium-steel alloy), graph 3 is PdH ship, graph 9 shows VH2, graph 10 shows FeTiH (hydride of titanium-iron alloy), and graph 11 shows MmNi Rainbow 6 (hydride of misch metal nickel alloy).

The hydrogenation pressure of a Z metal hydride at a constant temperature is generally slightly higher than the hydrogen decomposition pressure. If there is a metal ML that reacts with hydrogen at a relatively low temperature side and a metal MH that reacts with hydrogen at a relatively high temperature side, and if there is a common part in the reaction temperature range of both metals, then the differential pressure between the hydrogenation pressure and the hydrogen decomposition pressure can be calculated. The fact that temperature conversion of heat can be performed will be explained with reference to FIG. 5, taking into consideration the following. In addition, in FIG. 5, graph 1 is an equilibrium hydrogen decomposition pressure curve of the metal NL hydride, graph 2 is an equilibrium hydrogen decomposition pressure curve of the metal ML, graph 3 is an equilibrium hydrogen decomposition pressure curve of the metal MH hydride, Graph 4 is an equilibrium hydrogenation pressure curve of the metal core. In Figure 5, the temperature of the low temperature heat source is T,
By applying heat to the hydride of metal M,
The hydrogenated anti-material of the metal ML has an endothermic effect and transfers hydrogen to the pressure metal PL. (Graph 1).

The released hydrogen is stored, and after the hydrogen decomposition reaction is completed, the pressure of hydrogen is raised to 2 (> PL.) on the metal P and then applied to the original metal ML, causing an exothermic effect and increasing the temperature to T2 (> PL.). T,
) can be converted into heat (Graph 2). If this heat is applied to a metal MH hydride that reacts at a relatively high temperature, it will absorb heat and release hydrogen at a pressure of PH (Graph 3). If the released hydrogen is stored and the hydrogen decomposition reaction is completed, the pressure of hydrogen is increased to PH2 (>PH,) and given to the metal MH, it has an exothermic effect and takes the heat of temperature T3 (>T2). I will be able to put it out. (Graph 4). Therefore, in the method of the present invention, according to an embodiment in which a metal hydride is used as a reversible reactant at low to high temperatures, the following effects can be achieved.

{1} A scale that dramatically increases the energy concentration effect by effectively using multiple metal hydrides.

In other words, the range of temperature rise obtained by one heat input/output operation is not on the order of around 20 qo as in the nitric acid process, but on the order of tens to hundreds of degrees Celsius, and that it can be increased by multiple operations. The superposition of effects is effective. Therefore, there is a high possibility that the energy recovery efficiency can be improved compared to the conventional method and the conventional method.
'21 Since high-density thermal energy can be obtained from a low-quality heat source, a part of the obtained high-temperature source can be used as internal power for the energy concentration process, creating an independent system that does not depend on any other sources except the first heat source. can be made into paper. In terms of '3' uses, it has a wide range of applications in terms of energy conservation, such as preventing heat pollution such as waste heat, effectively using it for hot water supply and steam supply, and balancing the heat balance of each process in a chemical factory.

The method of the present invention is not limited to the metal hydrides mentioned above, and any other reversible reactant at low to high temperatures that exhibits the above-mentioned action can be used in the same manner as shown in FIG. 2.

Furthermore, in the method of the present invention, the storage container for the released gas and the combination reactor for the reversible reactant after the release of the gas are the same container, and two containers are provided for each reversible reactant. By using the binary unit as a binary unit and operating the binary unit in a binary system, it is possible to achieve a continuous energy concentrating method with a high operating rate as long as a heat source is available. Figure 6 shows an example of an embodiment of the above-mentioned method. When heat is constantly obtained from a heat source, two types of reversible reactants, a low-temperature reversible reactant and a high-temperature reversible reactant, are used (a so-called two-interrupt system) to decompose the The utilization rate is increased by using the same container as the gas coupling reactor as the discharged gas storage container.

In addition, since the decomposition release gas storage container and the gas coupling reactor are the same container, and there are two containers each for low and high temperature reversible substances,
They are differentiated into Q system and A system based on the process structure. In FIG. 6, 15 is a heat source, 16 is a heat exchange pipe on the heat source side, 1
7 is a thermal brine circulation pipe, 18-1 is a Q-channel first-stage reactor containing a low-temperature reversible reactant or its decomposition material (for example, metal M), and 18-2 is a similar B-channel first stage reactor. 18-3 is a Q-connected second-stage reactor containing a high-temperature reversible reactant or its decomposition material (for example, metal MH);
18-4 is the second stage reactor of the same aircraft, 19-I~19
14 are heat exchange pipes in the reactors 18-1 to 18-4, respectively, 20-1 to 20-16 are hot soot flow rate adjustment valves, and 21
-1 to 21-4 are flow rate adjustment valves for decomposition release gas, 22
23 is the consumption-side heated object, 23 is the consumption-side heat exchange valve, 24-
1 to 24-4 are pumps for circulating the heat medium; 25-
1 to 25-4 are hot soot tanks for storing the heating medium that overflows when the flow rate of the heating medium is adjusted and for preheating by forming a closed loop before transporting the heat, and 26-1 to 26-2 are decomposition product gases. This is a compressor that boosts the pressure. If the decomposition release gas storage container and the gas coupling reactor are the same container, and two containers are used for low-temperature and high-temperature reversible substances, which constitutes a binary unit, the process shown in Fig. 6 is equivalent to the Q system. It is a binary system consisting of two sets of binary knits with three threads.

FIGS. 7A and 7B are explanatory diagrams simply showing an example of the process shown in FIG. 6, that is, the operation of the binary system.

Figure 7A shows mode A, and Figure 7B shows mode B. Modes A and B indicate that the entire process is in one of the modes at a certain time, and the reaction is complete. This indicates that the mode can be changed to another mode by operating the valve.

In Figure 7, Q is the amount of heat at low temperature, Q2 is at medium temperature, and Q3 is at high temperature.
metal ML) and gas-bonded reactant (metal hydride MLH2
), MH, MHH2 are decomposition products of high-temperature reversible reactants (
Metal Nh) and gas bonding reactant (metal hydride MH ratio)
shows.

Due to the heat conversion action shown in FIG. 7, the process shown in FIG. 6 always performs a heat concentrating action.

In addition, in the method of the present invention, when three or more types of reversible reactants are used, a binary unit consisting of three or more containers each of Q and 8 connections shown in FIG. A binary system as shown in the figure may be used. According to the method of the present invention explained above, the following effects can be achieved. m It can be used as a temperature conversion process of thermal energy using two or more types of reversible reactants, and the extraction degree can be set over a wide range (about -20 to 950 qo).

■ In general, the scarlet heat source is about 2 pi0 or more, and the scarlet heat can be used effectively.

'31 As long as there is a heat source, the operating rate can be increased and a continuous energy concentration process can be formed.

■ Part of the energy obtained from the heat source can be used as an internal power source, and no external power supply is required.

[5] It can also be used to save energy and prevent thermal pollution due to its thermal condensation effect.

'6} No decomposition release gas storage container is required.

'7} The sensible heat loss of the reactor can be minimized, and the heat concentration efficiency can be greatly increased. The effects of the method of the present invention will be explained below by giving specific examples.

According to the embodiment shown in FIG. 6, a titanium-iron alloy hydride is used as a low-temperature reversible reactant, and a lanthanum-nickel alloy hydride is used as a high-temperature reversible reactant, and hot water at 2800 °C is converted to hot water or steam at 100 °C or higher. I conducted an experiment to change it. The heat transfer route is as follows. First, 280
0 heat of hot water (approximately 3.8 x 1 pkcal reactor 18-1
FeTiH, . o4 to release day 2, and pressurize day 2 (11. $tm) to 6 crab tm (the amount of compression work required for this pressure increase is approximately 1 x 1 pkcal per 1 x 1 pmol).
and the FeTi ratio in the reactor 18-2. ．． o to hydrogenate it, generating 64 oo of heat of hydrogenation reaction (approximately 4 x 1 pkca per 1 x 1 pmol).

Of this amount of heat, approximately 3.5×1 pkcal of heat could be extracted (the above is referred to as the first stage for convenience of explanation). Next, the heat obtained in the first stage (approximately 5.2
5HB to release the horse, and on the same day 2 (9. scales tm) was pressurized to milk number m and fed to LaNi5 in reactor 18-3 to hydrogenate it, at this time 110)○ hydrogen The reaction heat (approximately 5×IQ kcal per 1×1 pimol) was generated.

Of this amount of heat, approximately 4.8×1 pkcal was able to be extracted (the above is referred to as the second stage for convenience of explanation). Note that the above is for the case where both the first stage and the second stage are carried out at 1 × 1 pimol, so the amount of heat extracted in the first stage (approximately 3.
It was necessary to set the amount of heat (approximately 5.2×1 pkcal) as the heat input for the second stage.

In reality, it is necessary to perform the first stage and the second stage in a continuous flow, and make the amount of heat taken out in the first stage equal to the amount of heat input in the second stage. in this case,
The number of moles used in the second stage may be slightly smaller than the number of moles used in the first stage (if the first stage is 1 x 1 pimol, the second stage is about 6.7 x 1 pimol) good). 2 0 hot water (
When continuous flow is used, the final amount of heat extracted is approximately 3.3 x 1 pkcal.
Met.

[Brief explanation of drawings]

Figure 1 is the flow sheet of the conventional nitric acid circulation process, Figure 2
6 and 6 are flow sheets showing one embodiment of the method of the present invention, FIG. 3 is a PCT diagram of a metal hydride, FIG. 4 is a diagram showing an equilibrium decomposition pressure curve of a group of metal hydrides, and FIG. is a diagram showing the equilibrium hydrogenation pressure curve and equilibrium hydrogen decomposition pressure curve of a metal that reacts with hydrogen on the low temperature side and a metal that reacts with hydrogen on the high temperature side,
FIGS. 7A and 7B are explanatory diagrams simply showing an example of the operation of the process shown in FIG. 6. O picture spear 2 picture spear 6 picture spear 7 picture spear 3 picture spear 5 picture spear

Claims (1)

[Claims] 1 Heat from a low-temperature heat source is applied to a reversible reactant (hereinafter referred to as the first reversible reactant) to decompose it to release a gas, pressurize this gas, and then release the gas, followed by a first reversible reaction. By reacting and bonding with the substance, heat having a temperature higher than that of the heat source is extracted, and this heat is subsequently transferred to the reversible reactant having a reaction temperature range higher than that of the first reversible reactant (
The second reversible reactant (hereinafter referred to as "second reversible reactant") is decomposed to release a gas, and after this gas is pressurized, it is reacted and bonded with the second reversible reactant after releasing the gas, thereby increasing the temperature to an even higher temperature. An energy concentration method characterized by extracting heat from.