WO2017111765A1

WO2017111765A1 - Osmotic unit for a steam engine

Info

Publication number: WO2017111765A1
Application number: PCT/UA2016/000149
Authority: WO
Inventors: Игорь Николаевич РАССОХА
Original assignee: Игорь Николаевич РАССОХА
Priority date: 2015-12-23
Filing date: 2016-12-20
Publication date: 2017-06-29
Also published as: WO2017111765A8

Abstract

An osmotic unit for a steam engine consists of a circulating loop (1) which is divided by a selective membrane (4) into two compartments (A, B), wherein the circulating loop (1) has disposed therein a heating element (6), which is adapted to boil off a portion of a common fluid from compartment (A) without evaporating the common fluid in compartment (B). The common fluid in compartments (A) and (B) is mixed with substances (a) and (b) respectively, wherein the boiling point of the solution containing substance (a) is lower than the boiling point of the solution containing substance (b). This unit enables the circulation of a common fluid without the use of a pump.

Description

OSMOTIC STEAM UNIT

Description of the invention

Invention title: Osmotically unbalanced steam-osmotic steam engine assembly

The technical field to which the invention relates: Energy. Closed loop devices. PCT (WO) Code: F 01 K 25/04.

BACKGROUND OF THE INVENTION A device is known as an osmotic pump, where an element with a selective membrane is used, which converts the energy of osmosis into mechanical energy of a liquid stream (US Patent No. 0052279608 A 61 M 5/14 date of patent Jan. 18, 1994). However, this device is designed for small fluid flows and a one-time nature of the action. A continuous osmotic power plant with an energy converter that uses osmosis energy (the energy of mixing differently mineralized solutions through a semipermeable membrane) is also known. .2003. However, it is intended solely for pumping highly saline water, provided that fresh water is supplied through the pipeline and under conditions of operation of the pumps. This device and the like are not suitable for closed fluid circulation. Widespread are devices with closed circulation of a substance (water, freon, etc.), where vaporization of a liquid (i.e., a given substance) is used in a specific heating unit (for example, a steam boiler) with subsequent useful work of the vapor of this substance, which spends his energy on it and then returns to the heating device again. However, for substance a pump must always be used back to the heating device, otherwise circulation would not have occurred in a given direction.

The author obtained a patent of Ukraine for utility model UA 87009 (IPC (2013.01) F01K 25/04 (2006.01) F01K 27/00) "steam osmosis unit of a steam engine", offering a device that allows such circulation without a pump, through the use of osmosis energy - mixing energy of different mineralized solutions through a semipermeable (selective) membrane. That is, it is a device that functionally combines a universal boiler with an energy converter using osmosis energy. Paroosmotichesky unit of the steam engine is a device, the main element of which is a vessel divided selective membrane into compartments A and B, so that both compartments are solutions of a single liquid (e.g., water), respectively, with a substance _A and a substance _B (e.g., sulfuric acid H ₂ S0 ₄ as a substance, and lithium chloride LiCl as a substance _in ). Thus selective membrane must be transparent to said uniform liquid but completely opaque to substance _A and _a substance, i.e. this liquid will be uniform in both compartments in osmotic equilibrium temperature and relative balance. The selective membrane should not significantly interfere with the heat transfer between compartments A and B. In this case, a solution of a single liquid with substance _A should have two properties: a low boiling point and the fact that at this temperature only a single liquid will evaporate from it. In this case, a solution of a single liquid with a substance must have a high boiling point. In this case, the steam from compartment A should carry out useful work in the working unit (for example, spin a steam turbine or warm the room) and then get into compartment B, where it condenses into the solution and again enters compartment A. through a selective membrane. Thus, if in both compartments, the temperature reaches the boiling point of a single liquid solution with substance, then the solution of a single liquid with the substance will remain in the state of an ordinary liquid without signs of boiling. Thus, a solution of a single liquid with a substance in will, as a result of condensation of a pair of pure single liquid in it, be constantly diluted with a single liquid, and a solution of substance _A with a single liquid, on the contrary, will become more concentrated as a result of evaporation of a single liquid. The osmotic pressure of a single fluid will arise from compartment B to compartment A, and the corresponding diffusion of a single fluid from compartment B to compartment A will begin through a selective membrane. Thus, the circulation of a single liquid will begin according to the scheme "compartment A — steam — working unit — steam — compartment B — selective membrane — compartment A". In this way, energy savings for the operation of the pump will be achieved.

However, the specified device in the stated form basically cannot be built. The fact is that when two solutions of the same liquid, separated by a selective membrane (which passes only this liquid), are in osmotic equilibrium, the vapor pressure of this liquid over both solutions will be the same. And this means that these solutions will boil at the same time and begin to boil at the same temperature. The device proposed in this patent application overcomes this fundamental drawback.

The essence of the invention: two solutions from the device described in patent UA 87009 must be osmotically unbalanced, that is, the osmotic pressure of the working fluid in which during operation of the device is constantly directed from solution B to solution A, that is, the concentration of the working fluid in the solution And it must be constantly much lower than the concentration of the working fluid in solution B, and due to the evaporation of the working fluid from solution A, this concentration should be maintained constantly.

s Technical result: Thus, the device described in patent UA 87009 becomes technically possible.

Information confirming the possibility of carrying out the invention:

1) The vapor of a substance will condense in the solution of this substance if the boiling point of the solution is higher than the temperature of this vapor of a pure substance. In particular, in the article of prof. A. V. Shubnikova (journal "Science and Life", Ns 9/1984, pp. 76–78) a simple experiment by prof. Krapivina. The essence of the experiment is that if steam is removed from a vessel where pure water is boiling into another vessel, for example, with saturated aqueous solution of sodium chloride (NaCl), then the vapor (with a temperature of 100 ° C) will condense in this vessel, until the solution reaches its own boiling point (110 ° C).

2) Really there are selective membranes capable of purifying water (or another liquid), in particular, from salts, alkalis and acids. Moreover, they are often updated (cleaned) with sulfuric acid (for example, the osmotic membrane CSM-RE8040-BE. See also the site "Membrane technologies for wastewater treatment": http://enviropark.ru/course/view.php?id= 8). Membranes capable of operating in a sulfuric acid environment are well known and widely used. For example, US-A-3244620 describes a dialysis method for separating a strong acid from a mixture with a polymer using an anion membrane. Membranes with high thermal conductivity suitable for high temperature applications are also widely known: see, for example, patent RU 2446855 C2. The operation of such membranes is much more effective if they act in the direction of the action of osmotic pressure, as is the case in our case. So, a membrane that meets the requirements specified in the section "prior art" is technically possible, and such membranes really exist. 3) To confirm the feasibility of the invention, it is enough to give only one example of a practically possible device that meets the conditions of this application. For example, consider the working fluid water H ₂ 0, as substance _A selitru- potassium nitrate and potassium KN0 ₃ as _substance - sulfuric acid H ₂ S0 _4.

4) A solution of water with sulfuric acid can have any concentration, moreover, "When heating and boiling aqueous solutions of sulfuric acid containing up to 70% H2SO4, only water vapor is released into the vapor phase" (Raspberry IK Sulfuric acid // Big Soviet Encyclopedia 3rd ed., Vol. 23, p. 304). So, sulfuric acid at a concentration of less than 70% (for example, 60%) can be used as a substance if the boiling temperature of its solution B is significantly higher than the boiling temperature of solution A.

5) Unlike sulfuric acid, potassium nitrate KN0 ₃ is limitedly soluble in water: "Solubility of potassium nitrate in water (in grams per 100 grams of water): 31.6 (20 ° C); 245 (at 100 ° C). Saturated the solution boils at 118 ° C, while 100 grams of water contains 335 grams of nitrate "(Potassium nitrate // http://www.cniga.com.ua/index.files/nitratkalija.htm). In this case, potassium nitrate is also non-volatile (Potassium Nitrate // Material from Wikipedia - the free encyclopedia).

6) The molar mass of sulfuric acid is 98.08 g / mol (Sulfuric acid // Material from Wikipedia — the free encyclopedia), and potassium nitrate — 101.1032 g / mol (Potassium nitrate // Material from Wikipedia — the free encyclopedia), i.e. they are very close. So, you can compare aqueous solutions of these substances immediately after the mass fraction of water in them, that is, for example, by the ratio of 100 grams of water per specific amount of solution.

7) The boiling point of a 20% (by weight) aqueous solution of potassium nitrate at standard atmospheric pressure is 101.6 °, 25% solution - 102.1 °. At standard atmospheric pressure, the boiling point of a 20% solution of sulfuric acid is 104 °, 25% of the solution ~ 105.5 ° (24% - 105.25 °, 26% - 105.91 °) (Reference sulfuric acid / 2- ed., under the editorship of prof. K. M. Malina. - M.: Chemistry, 1971 - p. 105). So, it is obvious that under the conditions of the same atmospheric pressure over both solutions, the solution of potassium nitrate will boil at a temperature at which sulfuric acid will remain in a quiet liquid state. In addition, the very process of boiling a solution of potassium nitrate will stabilize the total temperature of the entire device at a level that does not allow the solution of sulfuric acid to boil. Therefore, under such conditions, solution A will boil, and solution B will not boil, at the same temperature of both solutions and the same atmospheric pressure over both solutions.

8) However, an equally important question is: under the conditions specified in paragraph 7, will the working fluid (water) flow through the selective membrane precisely in the direction from solution B (sulfuric acid) to solution A (potassium nitrate)? Here, with a practically equal molar mass of K1CHOz as a substance _A and sulfuric acid H ₂ S0 ₄ as a substance _{, the} ratio of their osmotic coefficients _{is of} decisive importance. The osmotic coefficient — the characteristic of the solvent — is the coefficient g, which is the ratio of the osmotic pressure in a real solution P to the osmotic pressure in an ideal Ilid solution of the same concentration as the real solution at the same temperature: g = Π / ffid. [Osmotic coefficient. Material from Wikipedia, the free encyclopedia]. That is, this is a characteristic of water as a solvent and a working substance in our device. At a temperature of 100 ° C and a concentration of 20% by weight, the osmotic coefficient of the KNO ₃ solution is 1.9891, at a concentration of 24% - 1.3269, 26% - 1.0835. At a temperature of 100 ° C and a concentration of 20% by weight, the osmotic coefficient of the H ₂ S0 solution is 0.9333, at a concentration of 24% - 1.0163, b 26% - 1.0428 (Aseyev GG Electrolytes Equiliibria in solutions and Phase Equilibria. Calculation of Multicomponent Systems and Experimental Data on the Activities of Water, Vapor Pressures, and Osmotic Coefficient— NY: Wallingford, UK: Bedell house, 1999. — Pp . 227-229). That is, the osmotic pressure will be directed towards the solution A (KNO ₃ ), which boils. This means that the device we invented is technically possible.

9) In paragraph 2 of the formula of utility model UA 87009, the “Unit according to paragraph 1, which is characterized by the fact that the source of heating is the addition of a single liquid to compartment A or B, if these solutions have a high positive temperature for mixing this single liquid with substance A and substance B (for example, mixing water with sulfuric acid H ₂ SO ₄ ). " This clause generally remains valid for the above example. But at the same time, “the dissolution of crystalline potassium nitrate is an endothermic process, since more energy is consumed to destroy its crystal lattice than is released during the hydration of K and NO ₃ ions .... and equals 36.0 kJ / mol” (Nitrate ions, hydration / / http://chem21.info/page/16320015720501010814206618822917713319515602809 21). On the other hand, the heat of dissolution of sulfuric acid in water is 74.2 kJ / mol (Dissolution - sulfuric acid // Big Encyclopedia of Gas Oil: http://www.ngpedia.ru/id378410pl.html). So, we have a positive difference of 38.2 kJ / mol. Since both substances (H ₂ SO ₄ and KN0 ₃ ) have approximately the same molar mass (mol), and under the condition of a closed cycle, the same number of water molecules will interact with them, this ratio should generally be maintained.

10) Of course, hydration processes play a large role in both solutions. For example, "In aqueous solutions, sulfuric acid almost completely decomposes into Н ₃ О +, Н5Оз +, and 2HSO4-. It forms hydrates H ₂ SO ₄ · pN ₂ O, where n = 1, 2, 3, 4, and 6.5. "(Sulfuric acid // Material from Wikipedia, the free encyclopedia). But osmotic exchange through the membrane does not impossible for hydrates or molecular hydrate complexes, but only exclusively for the molecules of water itself. On this basis, only “independent” water molecules (or НЗО + ions) that are not bound to hydrate complexes should pass to solution A from solution B through a selective membrane. Since the positive heat of dissolution of sulfuric acid in water is associated precisely with hydration processes, and in this case (in contrast to evaporation), hydration complexes do not directly dehydrate when passing through a membrane from solution B to solution A, it is difficult to say a priori that sulfuric acid solution in As a result of this process, osmosis will cool as much as it is heated due to the dissolution of the same number of water molecules in it. This is easy to understand if a reverse example were taken: a solution with negative heat of mixing. There is no experimental evidence that at a concentration of a particular solution A as a result of osmosis in the direction of a more concentrated solution B, this solution A would heat up just as much as it would cool as a result of direct dilution.

Note: The method of heating this device to a boiling state of a single liquid in compartment A is not the subject of this patent application. For this device, any method known in the art for heating a liquid in a steam boiler can be used: chemical energy of combustion, nuclear energy (at nuclear power plants), electric current, and the like.

List of drawing figures:

1. The circulation path of a single fluid

2. Compartment A with a solution of a single liquid and substance _A

3. Compartment B with a solution of a single liquid and substance _in

4. Selective membrane

5. The walls of the vessel

6. Work unit

7. Evaporation

8. Condensation

Claims

Claim:

1. “The osmotically unbalanced steam osmotic unit of a steam engine is a device whose main element is a vessel divided by a selective membrane into compartments A and B in such a way that in both compartments in relative temperature equilibrium are solutions of a single liquid (for example, water), respectively, with the substance _A (e.g., potassium nitrate KNO ₃₎ and veschestvomv (e.g., sulfuric acid H ₂ S0 _4), wherein the selective membrane must be transparent to said uniform liquid but completely opaque oh for the substance _A and the _substance, and also have a high thermal conductivity, and the solution was uniform liquid veschestvomv has a higher boiling point and the solution was uniform liquid veschestvomd has a lower boiling temperature and that at this temperature thereof evaporates exclusively common liquid , while the steam from compartment A must carry out certain useful work in the working unit (for example, spin a steam turbine or warm the room) and then get into compartment B, where it condenses into the solution (possible the condensation is already in the working unit) and through the selective membrane again enters compartment A, and solutions A and B must be osmotically unbalanced, that is, the osmotic pressure of the working fluid in which during operation of the device is constantly directed from solution B to solution A, that is, due to the evaporation of the working fluid, the concentration of the working fluid in solution A should be constantly lower than the concentration of the working fluid in solution B, therefore, when the temperature reaches the boiling point in both compartments If a solution of a single liquid with a substance is added, then the circulation of a single liquid will begin according to the scheme "compartment A — steam — working unit — steam — compartment B — selective membrane — compartment A".

2. The unit according to paragraph 1, which is characterized by the fact that the source of further heating is the addition to the compartment A or B of the most uniform liquids, if these solutions together have a high positive mixing temperature with this single liquid (for example, by mixing water with sulfuric acid H ₂ S0 ₄ ).