RU2446518C1 - Method to produce reserve power from thermal energy of sun and/or biogas - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: method to produce reserve power from thermal power of the sun and/or biogas by means of direct conversion of thermal energy of concentrated solar radiation and/or burnt biogas into electric energy in a barogalvanic generator includes heating and overheating of a working fluid in a liquid phase in a high-pressure cavity, its ionisation at the border: high-pressure electrode - an electrolyte, overflow of working fluid ions via an electrolyte layer under action of electrostatic field gradient, recombination of working fluid ions at the border: electrolyte - low-pressure electrode, and arrival of the working fluid in the form of an overheated steam from the low-pressure electrode into the low-pressure cavity, at the same time the working fluid amount previously set by weight is placed in the high-pressure cavity, and the low-pressure cavity is communicated with the earth atmosphere, where the low-pressure overheated steam of the working fluid is spontaneously released.

EFFECT: increased specific capacity of direct conversion of solar radiation or burnt biogas heat into electricity.

4 dwg

Description

The invention relates to energy, specifically to barogalvanicheskih generators for converting thermal energy into electrical energy.

Known methods for converting solar energy into electricity (B. Anderson, "Solar energy (Fundamentals of building design)", Moscow: Stroyizdat, 1982) [1].

There is a method and device for the direct conversion of solar energy into electricity using a barogalvanic converter (S. A. Sidortsev "On the barogalan converter of solar energy into electricity and heat", J. "Heliotekhnika" No. 3, 1984) [2].

The method of direct conversion of solar heat into electricity [2] is adopted as a prototype and has a number of promising advantages, which include: high energy efficiency, the absence of moving parts, cheap working fluid, low specific gravity, since in modern conditions the generator’s electrode block can be made using new nanomaterials (carbon nanotubes) and nanotechnology.

An object of the invention is to develop a method for producing backup electricity from the thermal energy of the sun and / or biogas burned.

The technical result that can be obtained by carrying out the invention is: 1 - increasing the specific power of the direct conversion of solar heat into electricity; 2 - generation of a predetermined one-time specified number of kilowatt hours of electricity.

To solve the stated problem with the achievement of the specified technical result in the known method [2] for generating electricity by directly converting heat into electric energy in a barogalvanic generator, by heating and overheating the working fluid in the liquid phase in the high-pressure cavity, its ionization at the boundary: high-pressure electrode - electrolyte, the transfer of ions of the working fluid through the electrolyte layer under the action of a gradient of the electrostatic field, the recombination of ions of the working fluid at the boundary: electrolyte - the low-pressure electrode and the influx of the working fluid in the form of superheated steam from the low-pressure electrode into the low-pressure cavity, the amount of the working medium, predetermined by mass, is placed in the high-pressure cavity, and the low-pressure cavity is communicated with the Earth’s atmosphere near the Earth’s surface, into which the superheated low pressure steam of the working fluid.

These advantages and features of the present invention will become apparent when considering the attached figures.

Figure 1. Functional diagram of a barogalvanic electric generator, which implements the proposed method for generating electricity: a) at the beginning of the generator; b) at the end of the generator.

Figure 2. Image in the T-S diagram (temperature - entropy): a set of thermodynamic processes characterizing the proposed method for generating electricity (solid lines) and the thermodynamic cycle of the prototype method for generating electricity (dashed lines).

Figure 3. The calculated values of the voltages (V) and specific power (W) at the terminals of the barogalvanic electric generator operating according to the proposed method (solid lines) and the prototype method (dashed lines).

Figure 1 shows: 1 - current-generating cell of a barogalvanic electric generator; 2 - high-pressure cavity of an overheated liquid working fluid (superheated liquid iodine) with a pressure of P ₁ = 2.5 atm, a temperature of T ₁ = 573 K, with a maximum mass of the working fluid M _r.t. = max and cavity volume 2 - V = const; 3 - a low-pressure cavity with a temperature T ₁ = 573 K of superheated steam of low pressure of the working fluid and a pressure of P ₂ = 2.5 · 10 ^-5 atm (superheated steam of low pressure iodine); 4 - porous high pressure electrode; 5 - porous (gas diffusion) electrode of low pressure; 6 - electrolyte (for example, silver iodide); 7 - hole (perforated) wall bounding the low-pressure cavity 3; 8 - spontaneous release of superheated low pressure steam P ₂ = 2.5 · 10 ^-5 atm (iodine) with a temperature of T ₁ = 573 K into the Earth’s atmosphere during the generation of electricity by cell 1; 9 - output electrical terminals of cell 1 of the generator; Q ₁ - supply of heat from solar radiation and / or biogas burned to cell 1 of the generator.

Figure 2 shows: K is a critical point; X = 1 - line of the liquid working fluid; (10-11-12-13-14) - a set of thermodynamic processes that characterize the proposed method of generating electricity: (10-11) - the process of heating a solid working fluid (crystalline iodine) from a solid state T _TV. to the melting temperature T _pl. = 386.6 K with absorption of solar heat Q ₂ ; (11-12) - the process of melting of a solid working fluid and its transition to a liquid state at a temperature T _pl. = 386.6 K with the absorption of solar heat Q ₃ - the heat of the phase transition; (12-13) - the process of heating a liquid working fluid (iodine) at a constant pressure of P ₂ = 2.5 atm from the temperature T _pl. = 386.6 K to a temperature equal to T ₁ = 573 K, - the temperature of the superheat of liquid iodine with heat absorption Q ₄ ; (13-14) - the process of isothermal generation of electrical energy in cell 1 at a temperature T ₁ = 573 K with heat absorption Q ₅ , with Q ₁ = Q ₂ + Q ₃ + Q ₄ + Q ₅ ; 13 - point on the TS diagram, in which the working fluid is in an overheated liquid state with a temperature T ₁ = 573 K and a pressure P ₂ = 2.5 atm; 14 - point on the TS diagram, in which the working fluid is in the form of superheated low pressure steam with a temperature T ₁ = 573 K and a pressure P ₂ = 2.5-10 ^-5 atm; (15-16-17-18-19-20-15) - thermodynamic cycle on the TS diagram of the prototype method of generating electricity: (15-16) - the process of heating a solid working fluid (iodine) to the melting temperature; (16-17) - the process of melting the working fluid; (17-18) - the process of heating and overheating of a liquid working fluid; (18-19) - isothermal power generation process; (19-20) - the process of cooling superheated steam of a working fluid; (20-15) the process of isothermal transition from dry vapor to a solid state of the working fluid (crystalline iodine).

Barogalanic electric generator works by the proposed method as follows.

The thermal energy of concentrated solar radiation and / or biogas burned Q ₁ raises the temperature of cell 1 to a temperature T ₁ = 573 K, at which the working fluid located in the high-pressure cavity 2 will be in an overheated state with a pressure P ₁ = 2.5 atm and a temperature T ₁ = 573 K.

на границе: электрод 4 - электролит 6, перетоке ионов через слой электролита 6 под действием градиента электростатического поля, рекомбинации ионов йода на границе: электролит 6 - электрод 5 по реакции

в полости 3.The working process of current formation in cell 1 consists in the ionization of high-pressure liquid iodine P ₁ in cavity 2 by reaction

at the border: electrode 4 - electrolyte 6, the flow of ions through the electrolyte layer 6 under the influence of the electrostatic field gradient, the recombination of iodine ions at the border: electrolyte 6 - electrode 5 by reaction

in the cavity 3.

The expansion of liquid iodine through the electrode block, including electrodes 4 and 5 and electrolyte 6, is isothermal with heat absorption Q ₅ (figure 2, process (13-14)). Low pressure iodine vapor P ₂ = 2.5 · 10 ^-5 atm (for prototype P2 it corresponds to the pressure of elastic vapors above solid iodine at a temperature of T = 300 K and amounts to P ' ₂ = 2.5 · 10 ^-4 atm (J. Kay, T. Laby “Tables of physical and chemical constants”, physical and mathematical literature, Moscow, 1962, p. 112) through the openings 8 of wall 7 will go into the atmosphere near the Earth’s surface. Earth does not have a partial pressure of iodine vapor - it is equal to 0. Air pressure of the order of 1 atmosphere will not prevent the rapid departure of superheated iodine vapor from the electric Electrode 5 through the openings 8 of wall 7 into the air environment near the Earth’s surface.This pressure P ₂ will be lower than the pressure of the elastic iodine vapor over the solid phase P ' ₂ = 2.5 · 10 ^-4 atm. Since in reality the pressure P _{2 is} unknown, then take it P ₂ = 2.5 · 10 ^-5 atm, different from P ' ₂ = 2.5 · 10 ^-4 atm 10 times in the direction of decrease.

The electromotive force of the current-generating cell 1 is determined by the formula:

where ΔG is the Gibbs thermodynamic potential drop - J / mol;

Z is the valency of the iodine ion, the charge carrier in the system Z = 2;

F is the Faraday number, 96500 C / mol ≈10 ^-4 C / mol;

;R is the gas constant

;

P ₁ = 2.5 atm; P ₂ = 2.5 · 10 ^-5 atm; T. _i.e. = T ₁ = 573 K. Substituting the values in the formula (1), we obtain the voltage at the terminals 9 of cell 1 of the generator:

The power density at the terminals 9 of the cell 1 of the generator is determined by the formula:

where J is the current density at the electrodes 4, 5, A / cm ² .

As an electrolyte, we take AgI iodide silver with a conductivity of æ _electron ≈0.1 1 / Ohm · cm, and we take δ = 0.1 cm as the thickness of the electrolyte, then formula (3) takes the form:

Figure 3 shows the calculated values of the voltages at the terminals 9 of one cell and its specific power calculated by the formulas (1 - 4) depending on the current density at the electrodes 4, 5 of cell 1. Similar values were calculated by the formulas (1-4) voltage V and specific power W of the current-generating cell operating according to the prototype method (dashed lines).

As can be seen from the graph (figure 3), when the cell 1 of the generator is in the maximum specific power mode, component W _gene = 0.108 W / cm ² (for a current-generating cell working according to the prototype method W _prot. = 0.05 W / cm ² ) the voltage at the terminals 9 of cell 1 will be equal to V _gene. = 0.33 V (for a current-generating cell operating according to the prototype method - V _prot. = 0.225 V), at a current density J _gene. = 0.33 A / cm ² (in a current-generating cell operating according to the prototype method, J _prot. = 0.225 A / cm ² ).

The specific consumption of the working fluid-iodine through the electrode block, including electrodes 4, 5 and electrolyte 6, cell 1 is uniquely determined by the Faraday law:

where g is the specific consumption of the working fluid through the electrode block of the cell 1, g / s;

I _floor - the total current generated by the entire surface of the electrodes 4, 5, S ₄ = S ₅ ;

S _cell. - the area of the electrode 4 or 5, S ₄ = S ₅ ;

A is the atomic weight of the working fluid, iodine, g / mol (for iodine, A = 126.91 g / mol ≈ A = 127 g / mol).

We take to calculate the specific consumption:

S _cell. = S _{electrode 4,5} = 100 cm ²

hourly flow rate of the working fluid will be equal to:

the daily consumption of the working fluid will be equal to:

mass of filling with working heat M _r.t. cavity 2 (figure 1) will be equal to:

where n is the time in days of operation of the electric generator.

Thus, the use of the proposed method for producing electric energy allows you to: increase the specific power of direct conversion of heat of solar radiation and / or biogas burned into electricity and ensure the generation of a reserve, one-time, predetermined amount of kilowatt-hours of electricity.

Claims (1)

A method of obtaining backup electricity from the thermal energy of the sun and / or biogas by directly converting the thermal energy of the concentrated solar radiation and / or biogas burned into electrical energy in a barogalvanic generator, by heating and overheating the working fluid in the liquid phase in the high-pressure cavity, ionizing it at the boundary : high pressure electrode - electrolyte, the flow of ions of the working fluid through the electrolyte layer under the influence of the gradient of the electrostatic field, the recombination of ions of the working fluid and at the boundary: an electrolyte - a low-pressure electrode and the influent of the working fluid in the form of superheated steam from the low-pressure electrode into the low-pressure cavity, characterized in that a predetermined mass of the working medium is placed in advance in the high-pressure cavity, and the low-pressure cavity is communicated with the earth's atmosphere , into which spontaneously released superheated low pressure steam of the working fluid.

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