RU2138885C1 - Unit of assemblies of solid oxide fuel elements with coefficient of thermal expansion exceeding that of their electrolyte - Google Patents

Abstract

FIELD: high-temperature solid oxide fuel elements. SUBSTANCE: in accordance with invention solid oxide fuel element presents hollow cylinder made from solid electrolyte with electrodes applied to its surface. Outer electrode is fabricated from material which coefficient of thermal expansion exceeds that of electrolyte. Assembly includes collection of solid oxide fuel elements, end anode and cathode bushings and intermediate bushings used for electric commutation. Coefficient of thermal expansion of bushings is equal to coefficient of thermal expansion of outer electrode of solid oxide fuel element. Unit incorporates at least two assemblies of solid oxide fuel elements, outer spacing rings made from electric insulation material, chambers to feed and remove anode gas in the form of tube board with cover sealed tight and current leads. In unit assemblies are connected in parallel electrically and by anode gas. EFFECT: improved adaptability to manufacture, reduced mass and size characteristics, increased electric and service life parameters. 16 cl, 24 dwg

Description

 The invention relates to electrochemical generators (ECG), in which the chemical energy of the fuel is directly converted into electrical energy, namely to high-temperature ECG (VT ECG) with solid oxide fuel cells (SOFC) using hydrocarbon gas (UG) as fuel, and as oxidizer oxygen - air.

 A characteristic feature of BT ECCH with SOFC is that most of its components, such as a battery, a converter that converts UG to hydrogen and carbon monoxide containing anode gas (AG), a chamber for afterburning combustible AG constituents in the battery, and a heat exchanger transferring it to the VT ECG of thermal energy to the heat carrier of the utilization unit, a regenerative heat exchanger for heating the incoming air - cathode gas (KG) with exhaust gases, parts, assemblies and equipment that form the anode (AP) and cathode (KP) is simple The equipment and channels for gas and exhaust gases, which circulate gas and gas, electrical switching and electrical insulation, equipment mounting and others, operate in a fairly narrow range of high temperatures of the order of 1173-1273K. This is due to the fact that at a minimum temperature inhomogeneity (at temperatures of the components close to the maximum operating temperature determined by their heat resistance), the best electrical characteristics of SOFC are achieved, the highest temperature of heat transferred to the heat exchanger, and therefore, the highest efficiency of VT ECG, as well as thermal voltage in parts and assemblies and increases their reliability.

 The combination of these components of the VT ECG forms a high-temperature zone (VTZ), which is assembled to provide a minimum outer surface and is insulated to reduce temperature inhomogeneity and heat transfer to the environment.

The design of VTZ, the materials used in its component parts are largely determined by the type of SOFC and, in particular, their KTP. The latter is due to the fact that for reliable connection of parts and assemblies with each other, especially with the requirement of gas tightness and (or) electrical conductivity, the identity (proximity) of the CTE of their materials is necessary, since otherwise, due to the high value of the maximum operating temperature, and therefore the high difference between the maximum and minimum operating temperatures, for example, the storage temperature of the decommissioned VT ECG, significant thermal stresses occur in these compounds, which reduce reliability. This is especially true for joints of parts and components made of ceramics due to their low ductility and tensile strength. So, for example, in patents [1] and [2] VTZ designs with SOFC in the form of tubes, with a supporting electrolyte, i.e. with KTR equal to KTR of their electrolyte. Ceramics were used as structural materials of the constituent parts of these VTZs, since its KTP is closest to the KTP of the electrolyte. In most of the known SOFC designs, zirconium oxide stabilized with yttrium oxide or scandium oxide [3] having a CTE in the temperature range of 300 ... 1273 K equal to 9.5 is used as an electrolyte. ..10.5 • 10 ^-6 1 / K [10]. Apparently, there are no oxygen-conducting materials suitable for electrolyte and having a thermal expansion coefficient, at least substantially larger than those indicated above, since their electronic conductivity, for example, cobaltites of rare-earth elements, also increases with increasing thermal expansion coefficient [11].

The use of ceramics as structural materials of VTZ components, especially VT ECG of high power, has, in addition to the above, the following disadvantages:
- low weight and size characteristics of VTZ heat exchange equipment due to the low thermal conductivity of ceramics and difficulties in manufacturing thin-walled parts;
- the complexity of mounting parts and assemblies of VTZ and VTZ components as a whole, especially ensuring gas tightness and (or) electrical conductivity of mounting joints and their control. The latter is associated with the need to use high-temperature adhesives (sealants) that require heat treatment at temperatures exceeding the maximum operating temperature;
- low values of permissible rates of temperature change in VTZ at operating modes due to the occurrence of significant thermal stresses due to low thermal conductivity, the thickness of parts and assemblies and low tensile strength, which impairs the maneuverability of VT ECG.

 Except for the insulators included in the VTZ, the lining, for example, in the afterburner, then its practically the only component with the need to manufacture ceramic materials is SOFC. And from the point of view of manufacturability of the other components of VTZ and their installation, improvement of weight and size characteristics, ensuring strength and reliability, improving the maneuverability of VT ECH, it is preferable, in comparison with ceramics, to use metals having the necessary heat resistance, heat resistance and manufacturability as their structural materials , in particular, the possibility of manufacturing semi-finished products from them (sheets, pipes, etc.), as well as good weldability. The latter is due to the fact that at such high operating temperatures, the most reliable connection of parts and assemblies with ensuring gas tightness and (or) electrical conductivity is a welded joint. Good weldability is especially important for mounting joints when assembling VTZ and VTZ components as a whole, since, otherwise, the requirements for preheating the subsequent heat treatment of welded joints are difficult to fulfill.

One of the most acceptable metal structural materials for VTZ, including for the battery, is the heat-resistant alloy KhN55MVTs (ChS-57), mastered in pilot production, which has good manufacturability (pilot production of forgings, sheets, pipes, shaped parts, including including cold deformation) and good weldability (welding materials have been developed and various welding methods and modes have been worked out), see, for example, [4], [5], [6]. The KTE of this alloy in the temperature range 300 ... 1273K is approximately 16.2 • 10 ^-6 1 / K, i.e. significantly more than the KTE of the SOFC electrolyte,
Patents [7] and [8] propose metal alloys of titanium with chromium and additives and chromium with iron and additives, respectively, for metal parts of planar SOFC assembly, in particular, for bipolar plates, the thermal expansion coefficient of which exceeds the thermal expansion coefficient of the electrolyte in the temperature range 300 ... 1273K no more than 10%. However, even such a difference in KTP leads to very high values of thermal stresses in the structural elements of the SOFC assembly - of the order of 250 MPa at a minimum operating temperature of 273 K. In addition, such manufacturability characteristics as deformation ability and weldability are not given, but it is known that high-chromium heat-resistant steels or alloys have low ductility and are difficult or limited to weld [9]. Nevertheless, there is at least a fundamental possibility of manufacturing parts from these alloys while ensuring the technological effectiveness of welding of mounting joints, for example, by preliminary (prior to assembly) welding to them transitional parts from an alloy with good weldability with the development of the necessary welding materials, welding and heat treatment modes, confirmation of the operability of this welded joint under operating conditions as part of VTZ for a given resource.

 Thus, it follows from the above that when creating a VT ECG with SOFC, it is necessary to overcome the existing discrepancy in exceeding the KTR of the most acceptable structural materials for VTZ components (heat-resistant alloys, for example, ChS-57 alloy) over the KTE of the SOFC.

The resolution of this discrepancy is one of the main tasks of the group of alleged inventions. This problem is solved by creating such a design of SOFC in which its thermal expansion coefficient exceeds the thermal expansion coefficient of the electrolyte used in it and is identical to the thermal expansion coefficient of the alloy of parts directly in contact with the SOFC in the assembly. These items include:
- current collectors supplying or removing electrons from SOFC electrodes;
- current paths providing an electrically conductive connection of opposite electrodes of adjacent SOFCs;
- current leads, providing the supply or removal of electrons from the assemblies of SOFC;
- parts forming the AP and KP for the movement of AG and KG along the corresponding SOFC electrodes.

 The first of the group of alleged inventions relates to SOFC assembly units, from which the VT ECG battery is assembled, as from unified units. A block is understood as a technologically complete assembly that has passed quality control and is designed with AP and CP, inputs and outputs from it of AG and KG, with current leads that provide electrical switching of the blocks in the battery.

 The technical result of the first of the group of alleged inventions is the creation of a SOFC assembly unit with high current efficiency (a fraction of the electrochemical oxidation of the fuel), high voltage efficiency, ensuring the conversion of carbon monoxide to an AP block, the minimum thermal stresses in parts with the same temperature difference between AG and KG at the outlet and entrance to the block and its reliability, good overall dimensions and manufacturability, as well as providing vibration and shock resistance of the block structure.

 To achieve the specified technical result, the assembly of SOFC with a KTE exceeding the KTE of their electrolyte, containing many SOFCs, cathode and anode current leads, electrical insulators, parts forming the cathode and anode space, inlets and outlets of the cathode and anode gas, and attachment points, according to the alleged invention equipped with at least two assemblies containing at least two SOFCs with a CTE exceeding the CTE of their electrolyte, in the form of a round hollow cylinder, the outer electrode of which has the functions of a carrier layer and cat yes, and the inner electrode is the function of the anode, the intermediate sleeves in terms of the amount of SOFC reduced by one, and the end anode and cathode sleeves with current collectors made of a heat-resistant or heat-resistant alloy with KTE identical to KTE of SOFC, for example, from ChS-57 or high-chromium alloy alloy, with the help of which high-temperature SOFC adhesives in assemblies are connected in series electrically and by anode gas with the possibility of gas-tight and electrically conductive connection of the end sleeves with the supply or exhaust parts anode gas and with assembly current leads, for example by welding, and external spacer rings of electrical insulation material, mounted outside of all the intermediate sleeves and the end anode sleeve or part of the sleeves, for example, the end anode sleeve and parts of the intermediate sleeves evenly spaced along the assembly length, and having the dimensions and shape of the outer surface, ensuring the spacing of the assemblies in the block with the required step, the anode gas supply and exhaust chambers in the form of a tube plate with a cover connected between with gas density and electrical conductivity, for example, by welding, as well as with the possibility of connecting to the last parts of the supply or removal of anode gas and (or) current supply to the unit with gas density and (or) electrical conductivity, for example, by welding, bent tubes for twice the number of assemblies with an outer diameter approximately two times smaller than the required spacing of the assemblies in the block, with the values of their folding, providing, together with the location of the holes corresponding to them in the tube plates of the anode gas supply and exhaust chambers, the required distance of spacing, and the cover covering the assembly, forming the cathode space of the block with the longitudinal movement of the cathode gas along the assemblies with its inlet and outlet from the block in the vicinity of the chambers, with camera mounts that limit their movement along the axis of the block, while the chambers, bent tubes and the casing with the mounting parts of the chambers are made of heat-resistant alloy with good weldability, for example, of ChS-57 alloy, the assemblies are connected in parallel electrically and along the anode g to the same end anode and cathode bushings with tube plates of the inlet or outlet chambers of the anode gas with corresponding bent tubes to ensure gas tightness and electrical conductivity of the joints, for example, by welding, and insulators are installed between the camera mounts and cameras.

The use of SOFC in the unit, in which the internal electrode has the function of the anode, i.e., the placement of the AP unit inside the assemblies, and the gearbox - outside the assemblies and inside the casing, has advantages compared with the placement of the gearbox inside the assemblies:
- improving the overall dimensions of the unit. According to calculations of the AG and KG flow rates, taking into account the required temperature heterogeneity of the VTZ at reasonable power costs for their circulation, the volume flow of the KG exceeds the volume flow of the AG by at least 60 times, and the required cross-sectional area of the KP exceeds the similar value of AP by at least 10 times. Thus, the required volume of AP unit is not more than 10% of the required volume of KP. This ratio of volumes is structurally most rationally realized when in the volume of the CP “islands” are placed AP, i.e. when the AP is placed inside the assemblies with the required SOFC inner diameter, and the control gear is located outside the assemblies placed inside the casing with the required spacing;
- electrical insulators made of oxide materials used in assemblies, blocks, and the battery as a whole in this case operate in an oxidizing atmosphere, which increases their electrical insulating and strength characteristics;
- the surface of the AP is reduced, while stagnant zones are practically eliminated in it, and this surface is mainly formed by SOFC anodes, on which water and carbon dioxide are formed as a result of the conversion of hydrocarbons as a result of electrochemical oxidation of the AG. This facilitates the solution of the UG conversion problem not in the VTZ converter, but directly in the AP of the unit (at its beginning along the AG), which increases the concentration of fuel components in the AG, and hence the thermodynamic stress (TDN) and voltage efficiency [1], [ ten]. The exclusion of stagnant zones in the AP reduces the likelihood of the formation of coal deposits with selectivity for catalytic pyrolysis of HCs and facilitates the purging of APs with an inert gas in the regimes of removing VT ECG from action;
- it is much easier to ensure uniformity of the distribution of AG in parallel-connected assemblies, the requirement for which is very stringent, especially when the current efficiency is close to unity, for example, by installing throttle devices in bent tubes in the area of their connection with the tube boards of the chambers or by the method described below . The uniformity of distribution of CG over assemblies during their longitudinal flushing, the requirement for which is less stringent due to small differences in oxygen concentrations and CG temperatures at the inlet and outlet of the unit (ensuring the required temperature uniformity of VTZ) and high values of the heat transfer coefficient from SOFC radiation (heat flux from heat SOFC is provided by radiation when the temperature difference between SOFC and surrounding assemblies is not more than 10 ... 15 K), is achieved in the usual way, for example, by spacing the assemblies in the block.

 The series SOFC electrical connection in the assemblies provides the highest value of efficiency in the voltage of the assembly as compared to the parallel SOFC connection under the remaining identical conditions. This is due to the fact that, in the course of the movement of the AG in the assembly assembly, the concentration of combustible components (hydrogen and carbon monoxide) decreases, and, therefore, the SPS for SOFC decreases. The difference between the TDN of the first and last SOFC along the direction of the AG becomes significant at high efficiencies in the assembly current, especially close to unity. With a parallel electrical connection of SOFC in assemblies, i.e. their work on the common current leads of the assembly, or at the same voltage at the SOFC, this difference in the TDN leads to uneven generation of the SOFC (current density in them) - the highest current density in the first SOFC and the lowest in the last SOFC along the AG, and therefore to additional polarization losses and a decrease in voltage efficiency [10]. With a series SOFC electrical connection in assemblies and a sufficiently large number of them, each of them operates in a narrow range of changes in the concentration of combustible components (changes in the TDN), and the indicated unevenness of the current density and additional polarization losses in the SOFC are significantly lower, and therefore, higher voltage efficiency as of each SOFC, and of the assembly as a whole for any current efficiency, including that close to unity. This connection also makes it possible to obtain the required battery voltage, or at least a significant part of it, on SOFC assemblies.

 The parallel electrical and anode gas connection of the SOFC assemblies in the block greatly simplifies the design and improves the overall dimensions and processability of the block compared to their serial electrical and parallel anode gas connections, because with a serial electrical connection, additional installation of gas-tight electrical insulators on the terminal bushings of the assemblies or bent tubes with the function of supplying or removing the AG from the assemblies and current leads for the serial electrical connection of the assemblies in the block and connecting the blocks to each other in the battery.

The spacing of the assemblies in the block with the required step by means of outer rings of electrical insulating material, covering the assembly of the casing and the selection of the corresponding values of the bending of the bent tubes and the location of the holes in the tube boards of the chambers provides
- vibration and shock resistance of the block structure in the transverse axis of the block direction due to the detuning of the frequencies of natural vibrations of the assemblies from the frequencies of external, including shock loads, by choosing the distance of the arrangement of the spacing rings along the length of the assemblies, i.e. their quantity. In this case, the number of rings is selected as minimally necessary, since their increase leads to an increase in the hydraulic resistance of the block in terms of KG and the cost of power for its circulation. The axis of the block is understood as a straight line passing through the centers of gravity of the cross sections of the block perpendicular to them, i.e. parallel to assembly axes;
-decrease in the unevenness of the consumption of KG in the cells of the longitudinal flow around the assemblies in the block,
-electric insulation of the assemblies from the casing of the block, and therefore, from the parts of the battery mount in VTZ;
The required value of the spacing step of the assemblies in the block is chosen optimal from the point of view of the weight and size characteristics of the block and the battery as a whole and the cost of power for circulating KG in the battery.

The longitudinal flow around the KG assemblies and the location of its entrance and exit from the block in the area of the chambers provides, in comparison with the transverse flow around:
- improving the overall characteristics of the battery and VTZ, because the space of the battery and VTZ necessary for supplying and removing AG from the blocks is simultaneously used for supplying and withdrawing KG from blocks;
- reducing the difference in temperature elongation of the assemblies, and hence the thermal stresses in them.

 The enclosure enclosing the assembly with the camera mount parts restricting their movement along the axis of the unit provides fastening of the current-carrying part of the unit (assemblies and cameras) in the enclosure at any position of the axis of the unit in space, the possibility of their relative relative movements under the influence of possible temperature differences between the assemblies and the enclosure and differences KTR of their materials, i.e. at minimum thermal stresses in them, and also provides impact resistance of the structure, including when the components of the shock load parallel to the axis of the block.

 The bent tube diameter, which is approximately two times smaller than the spacing of assemblies in the block, for example, along a triangular grid, provides, with acceptable dimensions of the bridges between the openings in the tube plates of the chambers, in terms of their strength and the possibility of making gas-tight and electrically conductive connections of the bent tubes with tube plates , for example, by welding, not exceeding the transverse dimensions of the chambers over the dimensions of the enclosing assembly of the casing. This allows you to assemble the blocks in the battery with virtually no gaps between their covers, which, on the one hand, reduces the dimensions of the battery and ensures almost the same volume characteristics of the battery and the block, and, on the other hand, makes it possible to use the covers as load-bearing parts for fastening the blocks in the battery and batteries in VTZ, for example, by connecting them together when mounting the battery by welding.

 The installation of electrical insulators between the camera mount parts and the cameras provides electrical isolation of the current-carrying parts of the unit from the casing, and therefore, from the battery mount parts in the VTZ.

 The above advantages of the design of the SOFC assembly unit, including its manufacturability, can practically be realized when using a heat-resistant alloy with good weldability as a structural material, for example, ChS-57 alloy, and SOFC with KTR exceeding the KTP of their electrolyte in the form of a round hollow cylinders, the outer electrode of which has the functions of the carrier layer and the cathode, and the inner electrode has the function of the anode.

 In addition, the axis of the block is located vertically in space, and the mounting parts of the anode gas supply or exhaust chamber are located in the lower part of the casing with the exception of moving the lower chamber downward relative to the casing.

 With this arrangement of the unit and the support of the lower chamber on the parts of its attachment to the casing in assemblies and SOFC, under the action of gravity, mainly compressive stresses arise, which are less than bending stresses, for example, when the axis of the block are horizontal, and their allowable value is especially for SOFC and high-temperature adhesives are significantly higher than bending and tensile stresses, which increases the reliability of the unit.

 In addition, in the block, the axis of which is located vertically in space, the anode gas is supplied and removed to the upper chamber and from the lower chamber, respectively.

 In the case of entering the AG block after the VTZ converter, in which, for example, steam conversion of the gas is carried out, when it moves along the assembly from top to bottom, flow stability is ensured due to an increase in the density of the gas during its electrochemical oxidation when denser layers are lower than less dense. In the opposite movement, on the contrary, the denser layers turn out to be higher than the less dense and a convective current arises, which at low AG velocities leads, together with diffusion, to additionally transfer mainly hydrogen along the AG flux and equalize its concentration along the assembly length, and therefore equalize TDN. Like any mixing process, the alignment of the TDN leads to an increase in entropy and to a decrease in the efficiency of the assembly voltage under other identical conditions.

 Let us consider the case of the addition of UG and its steam and carbon dioxide conversions to the unit at the beginning of AP assemblies, where, simultaneously with the conversion, electrochemical oxidation of AG occurs and the concentrations of water and carbon dioxide are close to zero. In this section of the assembly assembly, the TDN has a maximum value, and therefore, the maximum voltage efficiency is achieved under other identical conditions. In this case, the density along the AG decreases. When AG moves from top to bottom, as indicated above, a convective current arises, which, at low speeds, leads, together with diffusion, to additional hydrogen transfer against the flow. This process favorably affects the conversion process due to the inhibitory effect of hydrogen on the pyrolysis process (see, for example, [12]) and allows reducing or eliminating the content of water and (or) carbon dioxide in the carbon dioxide at the inlet of the unit introduced into it to exclude the process pyrolysis, which expands the assembly AP zone with the maximum TDN value, increases the assembly voltage efficiency, reduces the AG volumetric flow rate and assembly hydraulic resistance under other identical conditions. In the rest of the AP (after the end of the conversion), the flow of AT occurs, as in the case of the arrival of AG, after the VTZ converter.

 The movement of the AG or UG from top to bottom ensures the stable operation of assemblies connected in the block in parallel along the AG and electrically, without installing special throttle devices in the assemblies. This is explained by an increase in the average AG density along the length of the assembly with an increase in its current efficiency. For pure UG, this takes place with a current efficiency above approx. 0.4, with an increase in the content of water and (or) carbon dioxide in it, this value decreases and, at certain values of this content, becomes equal to zero, i.e. The UG becomes similar to the AG after the VTZ converter from this point of view. Indeed, if we assume that through any assembly the AG consumption has increased, this will lead to a decrease in the current efficiency of this assembly, which, in turn, firstly, will lead to an increase in the transformer substation and assembly voltage, and, consequently, to an increase in the generated by it the current and current efficiency in it, and secondly, to a decrease in the average density of the AG density along its length, to a decrease in the weight of the AG column in it compared to other parallel assemblies, and to a decrease in the flow rate through this AG assembly, and vice versa.

 With the opposite movement of the AG (from the bottom up) due to the same mechanism, it is possible if special measures are not taken, for example, throttle devices on each assembly with the necessary hydraulic resistance, instability and self-oscillations are not installed. Indeed, if we assume that a feature of an assembly increases AG consumption, then this will lead to a decrease in the weight of the AG column compared to other assemblies, and, consequently, to a further increase in consumption through it, and vice versa. However, with parallel electrical connection of the assemblies in the unit, these processes are somewhat stabilized, since with an increase in the AG flow rate the voltage and current generated by the assembly increase, which increases the current efficiency and the average AG density, i.e. parallel electrical connection of the assemblies limits the amplitude of fluctuations in AG flow rates in the assemblies. Installation of throttle devices does not exclude self-oscillations at intermediate and especially at small loads of VT ECG, since their hydraulic resistance at these loads is much less. These self-oscillations adversely affect the electrical and resource characteristics of the assemblies and the unit as a whole.

 In addition, in a block with a vertical axis in space and with an inlet and outlet of anode gas, respectively, to the upper and lower chambers, the inner diameter of the assemblies is made to provide the required value of the uneven efficiency in the current of the assemblies in the block, for example, exceeding the value proportional to the root cubic from the product of the sum of the assembly length and the projection length on the axis of the block of the lower bent tube to the average assembly current density through SOFC electrolytes at maximum load, with a proportionality coefficient, increasing with increasing concentration in the AG at the entrance to the block of non-combustible components, with an increase in the difference in hydraulic and electrical characteristics of the assemblies, due to the technology of their manufacture, and with a decrease in the required value of the non-uniformity of efficiency in the current of the assemblies in the block.

The value of the non-uniformity of the efficiency of the current of the assemblies in the block (δη _TSB ) is the positive maximum difference between the efficiency of the current of the assemblies and its average value equal to the efficiency of the current of the block (η _TBL ), referred to the latter. It depends on the difference in hydraulic and electrical characteristics established in the assembly unit, due to tolerances on the SOFC manufacturing technology, assemblies, and the entire unit, the geometric dimensions of the assemblies, the composition of the AG at the inlet to the unit, the average current density through the SOFC and η _TBL at maximum electrical load. A decrease in the value of δη _TSB increases the efficiency and improves the maneuverability characteristics of VT ECG under other identical conditions, i.e. identical values of the limiting efficiency for the assembly current at stationary loads ([η _TSB ] ^ST ) and at transient modes ([η _TSB ] ^D ).
The first value refers to the maximum value of the efficiency over the assembly current, which does not adversely affect the assembly’s performance during a given resource and ensures that the generated electrical power of the assembly does not exceed the so-called maximum due to the falling form of the current-voltage characteristic of the assembly, when, due to a voltage drop, the current increase does not lead to an increase , and to reduce power, and work at maximum is not profitable. When the first condition is met, the second is to some extent provided by the increase in the total area of the SOFC of the assembly, i.e. lower current density and higher voltage efficiency at maximum load.

The value [η _TSB ] ^D is understood as the maximum value of efficiency in the assembly current, which does not adversely affect the performance of the assembly for a given resource. The need to consider this quantity is due to the fact that the value of η _TBL does not remain constant during transient operating modes of a VT ECG, and for a short time (during a transitional mode) differs from the values in stationary modes. For example, if the programming of VT ECG parameters at different loads is performed at a constant value of η _TBL , i.e. at variable flow rates of AH and KG at the entrance to the blocks, then in a transitional mode, an increase in load in any range if the rate of increase in electric load exceeds the rate of increase in AH flow rate (the most common case), the value of η _TBL will first increase, reaching the maximum value excesses over the value in the stationary mode (Δη _TBL D), and then decrease to this value. The value of Δη _TBL D increases with the increase in the range of increase in load and rate of change, that is, with the improvement of the maneuverability of VT ECG. An increase in the value of η _TBL in this transitional mode until the assembly reaches the value of [η _TSB D], accompanied by a decrease in its voltage and a possible excess of the maximum power generated by it, has practically no effect on the efficiency of VT ECG due to the short duration of the transitional mode.

Из этого выражения видно, что с уменьшением δη_ТСБ растет величина [η_ТБЛ] , а следовательно, и экономичность ВТ ЭХГ, а в случае, если [η_ТСБ]^Д-Δη_ТБЛД > [η_ТСБ]^СТ , уменьшение δη_ТСБ позволяет увеличить Δη_ТБЛД на соответствующую величину и тем самым улучшить маневренные характеристики ВТ ЭХГ при прочих одинаковых условиях.From the above it follows that [η _TSB D] exceeds the value of [η _TSB ST]. Given these values, as well as the values of Δη _TBL D and δη _{TSB, the} value [η _TBL ] at stationary loads, including the maximum load, is selected from the condition that its minimum value determined by the formula

It can be seen from this expression that with a decrease in δη _TSB , the value of [η _TBL ] increases, and consequently, the cost-effectiveness of VT ECG, and if [η _TSB ] ^D -Δη _TBL D> [η _TSB ] ^ST , a decrease in δη _TSB allows increase Δη _TBL D by an appropriate value and thereby improve the maneuverability of VT ECG under other identical conditions.

Thus, the required value of the efficiency non-uniformity in the current of the assemblies in the unit [δη _TSB ] is determined on the basis of the analysis of the requirements for VT ECG, including cost-effectiveness and maneuverability.

 Consider the processes that determine the limiting values of the efficiency of the assembly current. With a constant flow of AG and KG through the assembly, we will increase the current, and therefore the efficiency in the assembly current, until the latter reaches a value of one. In this case, the concentration of combustible components in the AG at the outlet of the assembly will decrease to zero. With a further increase in current, the last SOFC of the assembly along the AG, and then the penultimate, etc., begins to work in the so-called oxygen pump mode, when oxygen ions passing through the electrolyte, discharged at the anode, enter the AP assembly in the form of oxygen molecules for the lack of a reducing agent there. Moreover, since the pressures in the AP and KP are usually close, for example, if there is an afterburner in the VTZ composition, and the oxygen concentration in the KP is higher than in the AP, then on this (these) SOFC TDN is directed to the same side as in other SOFC assemblies, but smaller in size [10]. The operability of these SOFCs and the location of the electric power generated by the assembly relative to the maximum power in this case, i.e., is the efficiency coefficient of the assembly current at a stationary or transitional mode, depends on the properties of the materials of the anode of the latter (last) during the AGFCFC and electrically conductive adhesive, connecting it to the anode current collectors of the corresponding end and intermediate bushings of the assembly. If they are made of oxidizable materials, for example, on the basis of nickel - cermet, then in the presence of oxygen with AP, their oxidation occurs, accompanied by a significant decrease in the electrical conductivity of the last SOFCs and the assembly as a whole, a decrease in voltage, and a shift in the maximum power to low currents. In this case, even if the processes of periodic oxidation and reduction of the anode and the electrically conductive adhesive do not affect the assembly’s performance, the efficiency value of the assembly current equal to unity is ultimate in the stationary mode, and if the assembly’s performance is affected, then in the transitional mode. In the case where the anode and the electrically conductive adhesive are made of materials that are resistant both to the reducing and oxidizing media, for example, based on a composite oxide material containing oxides of zirconium, cobalt, yttrium and some other metals, or from a mixture of cerium oxide and platinum , then the limiting value of efficiency in the assembly current, at least in the transition mode, will be more than unity. If in this case the current is still increased, then there comes a time when the cathodes of the last SOFC along the AG (when AG and KG move in the same direction) or the first SOFC along the AG (when AG and KG move in opposite directions) begin to be washed by a neutral medium ( all the oxygen from the KP went into the assembly assembly). This moment theoretically comes when the efficiency of the assembly current is numerically equal to the coefficient of excess air supplied to the VT ECG, and practically (with the uneven distribution of the CHG over the assemblies) and at a lower current efficiency. Since, when approaching this moment, the oxygen concentration in the CG becomes lower than in the AG (when the AG and CG move in the same direction), to transfer it from the KP to the AP, a part of the electricity generated by the assembly is required, which, from the point of view of the efficiency of the VT ECG becomes unprofitable. When AG and KG move in opposite directions, low oxygen concentrations in the first SOFC along the AG also significantly reduce the TDN and the assembly voltage as a whole. In addition, materials of SOFC cathodes, such as cobaltite-lanthanum-strontium or manganite-lanthanum-strontium, at low partial oxygen pressures begin to recover with a change in structure.

 Thus, in the case of using the last (last) SOFC for the anode along the AG and electrically conductive glue materials that are stable in both reducing and oxidizing media, the limiting value of the efficiency of the assembly current in transients lies in the range from unity to the excess air coefficient , reduced by the difference of unity and the size of the uneven distribution of CG assembly. The limiting value of the efficiency factor for the assembly current in the stationary mode can also lie within these limits provided that the generated maximum power does not exceed, and its value is determined, as indicated above, by choosing the SOFC current density at maximum load. Obviously, it is less than the limiting value of the efficiency in transition mode.

 Consider the dependence of the value of the non-uniformity of efficiency on the current of the assemblies in the block on the above parameters.

The hydraulic resistance of the assembly along the AG between the input and output chambers of the unit during laminar flow without taking into account local resistances and resistances of bent tubes, which usually make up a small amount of friction resistance, can be represented as
ΔP _Г = A • (ν • ρ) _SR • l • G _SB / d ⁴ , (1)
A-factor of proportionality;
(νρ) _СР - is the average product of kinematic viscosity and AG density over the assembly length;
l is the assembly length;
d is the inner diameter of the AP assembly;
G _SB - volumetric flow rate of AG at the entrance to the assembly.

 In the case of feeding into the AG unit after the converter, its volumetric flow rate does not change along the assembly length, since the electrochemical oxidation of hydrogen and carbon monoxide contained in the AG is not accompanied by a change in the number of molecules. As the calculations show, the kinematic viscosity of the AG decreases along its course, and the density increases, while their product remains almost constant (or rather, increases slightly with increasing efficiency in the assembly current, and this increase is smaller with increasing concentration of water and carbon dioxide in the AG at the entrance to the assembly). In the case of the conversion of hydrocarbons to the assembly assembly, the volumetric gas flow rate in the conversion section increases, and with further movement in the assembly remains constant. The kinematic viscosity in the conversion section increases, and the density decreases, and with further movement, on the contrary, the kinematic viscosity decreases, and the density increases. In this case, the hydraulic resistance of the assembly increases with increasing efficiency in the assembly current to approx. 0.4, and then remains almost constant. Thus, at sufficiently large (practically important) values of the efficiency of the assembly current, its hydraulic resistance is practically independent of the efficiency of the current and is proportional to the AG flow rate, the assembly length and inversely proportional to the fourth power of its inner diameter.

Using the generalized Faraday law, we express the AG consumption at the entrance to the assembly with its composition known through the total area of the SOFC of the assembly, the average current density through it and the efficiency of the assembly current
G _SB = B • (π • d • l • i _SB ) / η _TSB , (2)
where B is the coefficient of proportionality;
d, l are the diameter and total length of the SOFC of the assembly, respectively, it is assumed that they are close to or proportional to the internal diameter and length of the assembly assembly;
i _SB - the average current density through the SOFC electrolyte;
η _TSB - efficiency on the assembly current.

Substituting (2) in (1), we obtain
ΔP _G = C • (l ² • i _SB ) / (d ³ • η _TSB ), (3)
where C = A • B is the coefficient of proportionality.

The static (geometric) pressure drop of the AG between the output and input chambers of the block is determined by the formula
ΔP _ST = l • ρ _SR , (4)
where l is the sum of the assembly length and the projections of the bent tubes on the axis of the block;
ρ _CP - the average length density of AG.

The dependence of the difference in the static differential pressure of the AG in the assembly from the block average value from the difference between its current efficiency and current efficiency of the unit is determined by the formula
Δ (ΔP _ST ) = 1 • (∂ρ _CP / ∂η _TSB ) • (η _TSB -η _TBL ), (5)
where η _TBL is the block current efficiency.

 Since the composition of the AG does not change within the upper bent tubes, here by 1 we mean the sum of the assembly lengths and the projection of the lower bent tubes on the axis of the block.

As calculations show, the quantity (∂ρ _CP / ∂η _TBL ) depends on the composition of the AG at the inlet of the unit and weakly depends on the efficiency in the assembly current at large values. In the case of the conversion of carbon dioxide into the assembly AP, the quantity (∂ρ _CP / ∂η _TSB ) becomes positive when the efficiency over the assembly current is greater than approx. 0.4 and it increases with the growth of the latter. In case of a block after the AH converter VPP value (∂ρ _CP / ∂η _TSB) is positive throughout the range of the efficiency of the assembly changes the current from zero to the allowable value and is practically constant in the indicated range. In this case, the value (∂ρ _CP / ∂η _TSB ) decreases with increasing concentrations of water and carbon dioxide in the AG at the inlet of the unit, and it is always less than in the case of the conversion of UG to the AP assembly. With an increase in the length of the lower bent tubes, the value (∂ρ _CP / ∂η _TSB ) increases, i.e. they can play the role of “traction” sections by analogy with natural circulation, for example, in vertical steam-generating channels.

Введем величины:
δd = (d-d_СР)/d_СР - неравномерность гидравлических характеристик сборок в блоке, обусловленная допуском на технологию изготовления ТОТЭ, сборок ТОТЭ и блока в целом. Здесь принято, что указанная неравномерность определяется отличием внутреннего диаметра сборки d от среднего по блоку значения d_ср.;
δi_СБ= (i_СБ-i_БЛ)/i_БЛ - неравномерность средней плотности тока сборок в блоке, обусловленная различием электрических (вольтамперных) характеристик сборок вследствие допусков на технологию изготовления ТОТЭ и сборок ТОТЭ, где i_БЛ - средняя плотность тока блока;
δη_ТСБ= (η_ТСБ-η_ТБЛ)/η_ТБЛ - неравномерностъ КПД по току сборок в блоке.The dependence of the difference in hydraulic resistance of the assembly from the block average value is determined by the formula obtained from the expression of the total differential of formula (3)

We introduce the quantities:
δd = (dd _СР ) / d _СР - unevenness of the hydraulic characteristics of the assemblies in the block, due to the tolerance on the manufacturing technology of SOFC, SOFC assemblies and the block as a whole. It is assumed here that the indicated non-uniformity is determined by the difference in the internal diameter of the assembly d from the block average value d _cf. ;
δi _SB = (i _SB -i _BL ) / i _BL - unevenness of the average current density of the assemblies in the block, due to the difference in the electrical (current-voltage) characteristics of the assemblies due to tolerances on the technology of SOFC and SOFC assemblies, where i _BL is the average current density of the block;
δη _TSB = (η _TSB -η _TBL ) / η _TBL - the unevenness of the current efficiency of the assemblies in the block.

Изменение статического перепада давления на какой-либо сборке сопровождается изменением гидравлического сопротивления на ту же величину, поэтому, приравняв выражения (7) и (5), получаем

Обозначив через M = -3δd+δi_СБ , из выражения (8) получаем величину

где [δη_ТСБ] - требуемая величина неравномерности КПД по току сборок в блоке.Having determined the values of the partial derivatives, differentiating the formula (3) and substituting them and the introduced values in the expression (6), after the transformations we obtain

A change in the static pressure drop over any assembly is accompanied by a change in hydraulic resistance by the same amount, therefore, by equating expressions (7) and (5), we obtain

Denoting _SB by M = -3δd + δi, from expression (8) we obtain

where [δη _TSB ] is the required value of the non-uniformity of efficiency in the current of assemblies in the block.

(11) коэффициент пропорциональности.After transforming expression (9), we obtain the condition for ensuring the required value of the efficiency non-uniformity in the current of assemblies in the block
d _SR ≥D • (I • i _BL ) ^1/3 , (3)
Where

(11) coefficient of proportionality.

В этом случае коэффициент D возрастает с увеличением различия гидравлических и электрических характеристик сборок в блоке. Влиянием КПД по току блока на максимальной нагрузке на коэффициент D можно пренебречь, так как, во-первых, обычно эта величина близка к единице, а во-вторых, она, как указано выше, коррелирует с требуемой величиной неравномерности КПД по току сборок в блоке - чем меньше первая, тем выше вторая. При этом влияние на коэффициент D второй существенно больше, чем первой. Коэффициент D возрастает с уменьшением требуемой величины неравномерности КПД по току сборок. В случаях достаточно больших значений [δη_ТСБ] и малых значений М разность (M-2[δη_ТСБ]) может принимать нулевое и даже отрицательное значения, тогда величина [δη_ТСБ] обеспечивается при любом внутреннем диаметре сборки.It can be seen from expression (10) that the condition for ensuring the required value of the efficiency non-uniformity in the current of the assemblies in the block is satisfied if the internal diameter of the assemblies exceeds a value proportional to the cubic root of the product of the sum of the assembly length and the projection length onto the block axis of the lower bent tube and the average current density through SOFC electrolyte assembly. The average current density is taken from the maximum load of the VT ECG, since the program for changing parameters at intermediate loads is usually selected with a decrease in the AG flow rate at an approximately constant value of the efficiency of the current block. In this case, if the condition for ensuring the required value of the efficiency non-uniformity in the current of the assemblies in the block is satisfied at maximum load, then it is fulfilled with a large margin and at intermediate loads. It can be seen from expression (11) that the proportionality coefficient D increases with increasing concentration in the AG at the entrance to the block of non-combustible components, since the proportionality coefficient C increases and the value (∂ρ _CP / ∂η _TSB ) decreases. The influence of differences in hydraulic and electrical characteristics of assemblies, due to the technology of manufacturing SOFC, assemblies and block, on the value of the proportionality coefficient D, depends on their size and combination in the assemblies. For example, the equality of the value of M to zero is possible both at zero values of non-uniformities, and with such combinations when they cancel each other, for example, an assembly with high electrical characteristics has a larger internal diameter. However, in practical calculations it is more correct (in reserve) to calculate the value of M, when the irregularities combine unfavorably, i.e. take

In this case, the coefficient D increases with the difference in hydraulic and electrical characteristics of the assemblies in the block. The influence of the efficiency of the block current at maximum load on the coefficient D can be neglected, because, firstly, usually this value is close to unity, and secondly, as indicated above, it correlates with the required value of the unevenness of the current efficiency of the assemblies in the block - the smaller the first, the higher the second. Moreover, the influence on the coefficient D of the second is significantly greater than the first. Coefficient D increases with decreasing the required value of the unevenness of efficiency in the current of the assemblies. In cases of sufficiently large values of [δη _TSB ] and small values of M, the difference (M-2 [δη _TSB ]) can take zero or even negative values, then the value of [δη _TSB ] is provided for any internal diameter of the assembly.

 From the above it follows that the AG moves from top to bottom and condition (10) is satisfied, i.e. the low hydraulic resistance of the AP assemblies eliminates the negative effect on the block characteristics of the always uneven electrical characteristics of the assemblies, since in this case assemblies with the best electrical characteristics generate greater electrical power, and with the worst, lower power and ensure the achievement of high current efficiency and the efficiency of the voltage of the unit, and hence the high efficiency of the battery.

 In addition, the unit is equipped with assemblies in which the anode of the last or last SOFC along the anode gas in the assembly and the high-temperature electrically conductive adhesive connecting them to the anode current collectors of the respective bushings are made of materials resistant to both reducing and oxidizing media, for example , based on a composite oxide material containing oxides of zirconium, cobalt, yttrium and some other metals, or a mixture of cerium oxide and platinum.

 As shown above, the use of such materials for the anode and electrically conductive adhesive in the last or last SOFC along the AG provides an increase in the values of the limiting efficiency in the assembly current at stationary loads and transient conditions, which increases the efficiency and improves the maneuverability of VT ECG. The possibility of such use of materials is due, as will be shown below, to the design of SOFC, in which the requirement for the thermal expansion coefficient of the anode material is limited only from above - the thermal expansion coefficient should be slightly smaller than the thermal expansion coefficient of the cathode, which expands the field of application of the anode materials.

 In addition, in the block, the cathode gas entrance into the cathode space is made in the region of the anode gas removal chamber, and the exit is in the region of the anode gas supply chamber, i.e. the movement of the anode and cathode gases is organized by a countercurrent.

 As indicated above, when the anode gas moves through the assembly, the concentration of combustible components, TDN and the voltage of the SOFC generated current decrease, and consequently, the heat release increases [10), and in the case of equal lengths of SOFC, the heat flux and temperature difference along the SOFC and cathode gas along the way AG movements. Since the heat in the SOFC is mainly allocated to the CH, the temperature of the SOFC is determined by the temperature of the CH, which increases as it moves into the control unit. Therefore, in a countercurrent, when SOFC with the highest heat is washed by KG with a minimum temperature, the difference in temperature of SOFC in the unit is less than in direct flow. In the case of the conversion of HC to the assemblies requiring heat supply to the SOFC located at the beginning of the assemblies, in counterflow, when the conversion section is washed by high temperature CH, the temperature difference between the SOFC in the unit is also less than with direct flow. This provides the possibility of approximating the temperature of SOFC to the maximum value, and therefore, ensures maximum efficiency in terms of the voltage of the unit and its efficiency under other identical conditions.

 In addition, the unit is equipped with assemblies in which the lengths of the last or last SOFC along the anode gas in the assembly are made larger than the lengths of the remaining SOFC in the assembly.

 An increase in the length of the last or last SOFC assemblies along the AG decreases the heat flux from them, and, consequently, the temperature difference between SOFC and CH due to both an increase in the voltage of the current generated by them due to a decrease in the current density through the electrolyte, i.e. reduce heat and increase the heat release surface. The choice of the lengths of these SOFCs is determined by the required difference in the temperatures of the SOFC in the unit. The possibility of increasing the SOFC length in assemblies, as will be shown below, is due to the use of intermediate and end bushings with current collectors in them.

 The first of the alleged inventions is illustrated by drawings, where in FIG. 1 shows a longitudinal section through a block; FIG. 2 is a section AA in FIG. 1, FIG. 3 is a section bB in FIG. 1, in FIG. 4 is a view D in FIG. 1, in FIG. 5 is a cross-section BB in FIG. 1, in FIG. 6 is a section GG in FIG. 1, in FIG. 7 is a view B in FIG. 1, in FIG. 8 is a section 3-3 in FIG. 7, in FIG. 9 is a view of FIG. 1.

 A block located vertically in space contains SOFC assemblies 1, including SOFC 2 with a CTE exceeding the CTE of their electrolyte, with an external supporting cathode 3, electrolyte 4 and an internal anode 5, intermediate sleeves 6 in terms of the number of SOFCs reduced by one, with the anode 7 and cathode 8 current collectors, end anode sleeve 9 with anode current collector 10 and adapter 11, end cathode sleeve 12 with cathode current collector 13 and adapter 14, with which SOFCs in the assembly are connected in series electrically and via AG to connection to the adapters of the end bushings of the AG supply or withdrawal parts and current leads to the assembly with the provision of electrical conductivity and gas tightness, for example, by welding, and the outer spacer rings 15 made of electrical insulation material installed externally, for example, the end anode bush and parts evenly spaced assemblies of intermediate sleeves and having the configuration of the outer surface in the form of a spline surface with a diameter along the protrusions of the slots equal to the required spacing sp the orc in the block, the supply chamber 16 and the AG outlet 17 from the block, in the form of a tube plate 18 and a cover 19 with the current supply of the block 20, bent tubes 21 connected by welding and placed respectively in the upper and lower parts of the block by the number of assemblies multiplied by two, with an outer diameter of approximately two times smaller than the distance of the distance of removal, and with the values of bending, providing, together with the location of their holes in the tube boards of the chambers, the required distance of distance connecting the adapters of the same end sleeve to assemblies with tube plates of cameras by welding, i.e. connecting the assemblies in the block in parallel electrically and along the AG, for example, as shown in the drawings, the adapters of the end anode bushings with the AG supply chamber and the adapters of the end cathode bushings with the AG exhaust chamber, covering the SOFC assemblies casing 22 with the KG input to the block 23 in the region AG exhaust chamber, with the output of KG 24 in the vicinity of the AG supply chamber and with mounting parts 25 of the AG exhaust chamber to the casing, restricting its movement along the casing down, and an electrical insulator 26 installed between them.

 A block is assembled, for example, as follows. Bent tubes 21 corresponding to the location of the cathode assembly in the block are welded to the assemblies 1 in the special tool. Then, the assemblies, according to their location in the block, are assembled in the special tool to ensure that the outer distance rings 15 are touched with similar rings of adjacent assemblies. In this case, the ends of the bent tubes 21 are arranged in steps corresponding to the steps of the holes in the tube plates 18. By means of a special tool, the ends of the bent tubes 21 are installed in the holes of the tube plates 18 and welded to ensure gas tightness and electrical conductivity of the connection. Covers 19 are attached to tube plates 18 with current leads 20 installed on them and, if necessary, with AG supply or removal parts to the unit, and they are welded to ensure gas tightness and electrical conductivity of the joints. Upon completion of each of these operations or a group of them, quality control is carried out, if necessary. A female casing 22 is installed, for example, made of two longitudinal parts that are pulled together in the fixture to ensure that their inner surfaces touch the outer spacer rings 15 of adjacent assemblies and are welded with longitudinal seams. An insulator 26 and parts 25 of its fastening to the casing are mounted on the chamber 17, and they are welded. After that, the final quality control of the manufacturing unit is carried out, including the tightness of the AP unit. Due to the use of alloys with good weldability, heat treatment of the block, as a rule, is not required.

 The block works as follows. The UG or AG after the VTZ converter through the pipeline (not shown in the drawing) is supplied to the supply chamber 16, where it is divided into parallel flows, which through the bent tubes 21 enter the AP of assemblies 1. When the UG or AG moves in AL assemblies from top to bottom, respectively electrochemical oxidation and conversion at the beginning of AP assemblies and electrochemical oxidation in the rest of the DP or electrochemical oxidation with the formation of water and carbon dioxide. The AG flows fulfilled in the assembly assemblies through bent tubes 21 enter the AG 17 exhaust chamber, where they are combined and sent through a pipeline (not shown) to VTZ. CG from VTZ through input 23 enters the casing 22, passes the CP block countercurrently with respect to the movement of the AG and with longitudinal washing of the assemblies, and then through exit 24 enters the VTZ. When KG moves to the block KP, the oxygen concentration in it decreases due to its electrochemical transition to the assembly assemblies, and the temperature increases due to the heat release of the SOFC of the assemblies throughout the stack or may decrease in the section of UG conversions due to the endothermicity of the conversion process. The flow of electrons from the VTZ batteries through the current lead (not shown in the diagram) goes to the cathode current supply of block 20 and then through the cover 19 to the tube plate 18 of the exhaust chamber AG 17, where it is divided into parallel flows, which are bent through tubes 21, adapters 14, cathodic current collectors 13 of the end cathode bushings 12 are fed to the cathode 3 SOFC. Oxygen ionization occurs in the SOFC cathode, and electrons are transferred by oxygen ions through electrolyte 4 to anode 5, where electrochemical oxygen reduction (AG oxidation) takes place, and an electron beam with an increased voltage enters the anode current collector 7 adjacent to the intermediate sleeve 6 and through it to it cathodic current collector 8. After passing through all the SOFC assemblies, the electronic stream with the voltage of the block enters the anode current collector 10 of the end anode sleeve 9 and through its adapter 11, the bent tube 21 blunt in the tube plate 18 AH inlet chamber 16, where it is combined with other similar streams assemblies, and further through the cap 19 of this chamber, an anode current feeder unit 20 and the battery tokovod (in Fig. not shown) back into it. Electrical isolation of the current-carrying parts of the block from the casing 22 and the fastening parts 25 of the AG exhaust chamber is carried out by an electric insulator 26 and external spacer rings 15. The latter also provide vibration and shock resistance of the blocks.

It is also possible to design a block with the opposite direction of the electron flow movement relative to the direction of movement of the AG and KG, in this case, the current-carrying part of the block rotates 180 ^o while maintaining the direction of motion of the AG from top to bottom, and KG from the bottom up, while the cathode current supply is located on the cover the AG 16 inlet chamber, and the anode current lead on the cover of the AG 17 outlet chamber.

 The proposed design of the SOFC assembly unit has improved mass and size characteristics and manufacturability, high efficiency current and voltage and high reliability, vibration and shock resistance, provides AG conversion to the AP unit, and high maneuverability of the VT ECG.

 The second of the group of alleged inventions relates to SOFC assemblies, the most important component of the block, namely SOFC assemblies in which they are connected in series electrically and by anode gas.

 The closest analogue is the patent [13]. It describes the assembly design of tubular elements used primarily in oxygen pumps. The elements are connected in series electrically and through the anode gas by intermediate bushings, for example, bell-shaped, performing the functions of a current passage and a part forming the anode space of the assembly. At the extreme elements of the assembly, end anode and cathode bushings are installed that perform the functions of current supply and parts for supplying or removing anode gas, with which, as well as other parts, several assemblies can be connected into more complex structures, for example, the blocks discussed above. The tubular elements are made with a supporting electrolyte, the thickness of which is very significant (5. ... 10 mm) and thin (10 ... 20 μm) electrodes, i.e. their KTP are almost equal to the KTP of the electrolyte. As the material of the latter, cerium oxide stabilized by metal oxides, which has the properties of an electrolyte with oxygen conductivity in oxygen-containing media, is used. The most acceptable material for the manufacture of bushings, according to the authors, is ceramics (manganite-lanthanum-strontium) due to the proximity of its KTP to the KTP of the elements and its stability in oxygen-containing environments. This explains the area of use of the assembly-oxygen pumps. The elements are connected to the bushings using high-temperature adhesives (sealants) that provide electrical conductivity and gas tightness and have KTR identical to the KTP of the elements and bushings.

The disadvantages of this design are:
- the use of tubular cells with a supporting electrolyte, i.e. with KTR equal to KTR of their electrolyte. This significantly limits the range of materials for the manufacture of bushings that ensure the performance of assemblies for a given resource and the possibility of using them in ECG (in SOFC assemblies). Moreover, within the framework of the solutions proposed in this patent, it is almost impossible to create an assembly of SOFC. Indeed, the authors recognized the best material for manganite-lanthanum-strontium bushings as having a CTE significantly higher than the CTE of the elements, i.e. with this difference in KTP, achieving density and electrical conductivity of the connection of the bushings and elements even for a small resource is problematic. The other materials possible for the manufacture of bushings indicated in this patent, such as high-chromium alloys, have, as indicated above, KTP about 10% higher than KTP of manganite-lanthanum-strontium, and nickel-chromium alloys are significantly higher, and when using them, assembly performance is not ensured . Manganite-lanthanum-strontium cannot be used as a sleeve material in SOFC assemblies because of its instability in reducing media (in AG). In addition, a significant thickness of the electrolyte reduces the voltage efficiency of the cell and the assembly as a whole due to significant ohmic losses during the movement of ions through the electrolyte;
- the absence of current collector sleeves in the design. This, along with thin element electrodes, limits the permissible length of elements in the assembly due to an increase in ohmic losses during the movement of electrons along the electrodes to the bushings and a decrease in the efficiency of the assembly voltage. In addition, this makes it difficult to provide the required rigidity and strength of the assembly, in particular bending. In the proposed design, this, apparently, is provided by a thick electrolyte and massive bushings of a very complex configuration. However, this worsens, as indicated above, the electrical characteristics of the assembly, as well as its hydraulic and weight and size characteristics and manufacturability.

 The technical result of the second of the group of alleged inventions is the creation of a SOFC assembly in which they are connected in series electrically and by anode gas, ensuring its manufacturability, operability for a given resource, impact and vibration resistance, high voltage efficiency at almost any SOFC lengths and thicknesses their electrodes, high current efficiency.

 To achieve the specified technical result, the assembly of SOFCs with a KTE exceeding the KTE of their electrolyte, containing many SOFCs, intermediate sleeves by the number of SOFCs reduced by one, and the end cathode and anode bushings with which SOFCs are connected in series electrically and through the anode gas and it is possible connection to the assembly of parts for supplying and removing anode gas and current leads, according to the proposed invention is equipped with at least two SOFCs with a CTE exceeding the CTE of their electrolyte and identical KTP of the material of the bushings, in the form of a round hollow cylinder, the outer electrode of which has the functions of a carrier layer and the cathode, and the inner electrode has the function of the anode, the intermediate sleeves are made of a heat-resistant or heat-resistant alloy with KTR identical to KTR SOFC, for example, of ChS-57 or high-chromium alloy alloys in the form of two hollow cylinders of larger and smaller diameters with the function of the cathode and anode current collectors, respectively, with lengths not exceeding the lengths of the SOFC connected by them, with an inner diameter of a larger cylinder, ensuring which incorporates a SOFC in it, and with an outer diameter of a smaller cylinder that allows it to enter the neighboring SOFC, with windows for supplying cathode and anode gases, respectively, arranged to overlap the SOFC, articulated by a transition sheath of revolution, for example, conical with the functions of current passage and part , forming the anode space, the end cathode and anode bushings are made in the form of a hollow cylinder from the same alloy as the intermediate bushings, with the function of the cathode and anode current collector, respectively , with a length not exceeding the length of the corresponding end SOFC of the assembly, with an inner diameter that allows the SOFC to be embedded in it, and with an external diameter that allows it to enter the SOFC, respectively, with the windows for supplying the cathode and anode gas, respectively, located to ensure them overlapping SOFC, coupled with an adapter, providing the possibility of gas-tight and electrically conductive connections with the parts of the supply or removal of the anode gas and the assembly current path, for example, by welding made from the same alloy as the current collector in the case of using an alloy with good weldability, or with a composite adapter in the case of using an alloy with limited weldability, consisting of two parts interconnected during the manufacture of end bushings with electrical conductivity and gas tightness, for example, by welding, one of which is articulated with a hollow cylinder, made of the same alloy, and the second of the alloy with good weldability, and the connection of SOFC with the bushings is made using high-temperature structural adhesives with KTR identical to KTR SOFC and bonding temperature above the assembly maximum operating temperature, but lower than the permissible heating temperature of the sleeve material and the SOFC manufacturing temperature, namely, electrically conductive stable in the cathode gas, for example, based on composite materials with a phosphate binder, for bonding SOFC cathodes with cathodic current collectors of bushings with the required conductivity and strength, conductive resistant in the anode gas, for example, based on nickel cermet, for connections of SOFC anodes with anode current collectors of bushings providing the required electrical conductivity and strength, electrically insulating gas tight in cathode and anode gases, for example, based on glass-ceramic materials or porcelain for sealing the ends and cylindrical surfaces of SOFCs adjacent to them and connecting them to the adjacent surfaces of the bushings with ensuring gas tightness and the required strength.

The use of SOFCs in assemblies with KTR exceeding the KTR of their electrolyte and identical to the KTP of the material of the assembly parts in contact with them (bushings) makes it possible to use more technologically advanced, expanding design options for bushings heat-resistant and heat-resistant alloys mentioned above. In particular, this is precisely what makes it possible to make bushings with current collectors in the form of hollow thin-walled cylinders with windows for supplying KG and AG to the corresponding SOFC electrodes. The presence of current collectors made of metal materials with significant electrical conductivity significantly reduces the ohmic resistance of the assembly and, with other conditions being the same, increases the efficiency of the assembly voltage due to a decrease in the path of electrons along the SOFC electrodes. In this case, the required value of the ohmic resistance can be practically ensured for any thickness of the electrodes and the length of the SOFC, i.e. they can be selected based on other requirements. The location of SOFC between current collectors made of alloy increases the bending and axial strength and rigidity of the assemblies and provides a choice of the thickness of the electrodes and electrolyte almost exclusively from the conditions for ensuring the integrity of SOFC and the required electrical characteristics. This reduces the material consumption, weight and size characteristics and the cost of assemblies under other identical conditions. The choice of the lengths of the hollow cylinders of the current collectors with no exceeding the lengths of the corresponding SOFC, i.e. with the exception of touching the ends of these cylinders on the outer or inner surfaces of the respective adjacent bushings, firstly, it eliminates a short circuit between the SOFC electrodes, and secondly, when the assembly is installed vertically with a support below, it provides the SOFC and their gas-tight electrically insulating connection to the bushings under compressive stresses , which increases their reliability. The dimensions, configuration, number of windows in hollow cylinders, their thickness are selected based on the achievement of an optimum between the ohmic resistance of the assembly, the working area of the SOFC electrodes, the strength and rigidity of the assembly, as well as the hydraulic resistance of the assembly according to AG and the external transverse dimension of the assembly. The required size of the working area of SOFC electrodes is also achieved by using electrically conductive adhesives connecting the SOFC electrodes to current collectors, with open porosity, providing gas exchange between the KP or AP and the corresponding SOFC electrodes, and the required electrical conductivity and mechanical strength of these compounds - by choosing the adhesive material and geometric dimensions these compounds. Overlapping the windows of current collectors with SOFC cylindrical surfaces together with a SOFC gas-tight electrolyte, sealing of SOFC ends (in case of minor defects of their SOFC) and their adjacent cylindrical SOFC surfaces and their gas-tight connection with the adjacent surfaces of the bushings using gas-tight electrically insulating glue eliminates gas leakage between the AP and KP assembly. Sealing the ends of SOFC also eliminates the short circuit of SOFC electrodes and significantly reduces leakage currents. Ensuring the required mechanical strength of this compound is achieved by the choice of material of electrically insulating adhesive and geometric dimensions. Application for bonding SOFC with bushings of high-temperature adhesives with KTR identical to KTE of SOFC and bushings, and with a bonding temperature higher than the maximum temperature of the assemblies, but lower than the permissible heating temperature of the material of the bushings (for example, the temperature of phase transformations in it or the melting temperature), and the manufacturing temperature SOFC, when, as will be shown below, the electrolyte and the anode remain in a compressed state, ensures the strength of the joints, as well as the reliability of the bushings, SOFC and the assembly as a whole. The use of composite adapters in the end sleeves when using an alloy with limited weldability as the material of the sleeves allows assemblies to be connected to the exhaust parts or to supply AG to them and current leads made of alloys with good weldability during the installation of more complex structures, for example, the above blocks by welding, as the most technologically advanced and reliable way. The use of ChS-57 alloy bushings as a material with good weldability and ductility has an advantage over high-chromium alloys:
- improves the manufacturability of the manufacture of bushings, and therefore, reduces the cost of their manufacture, for example, the sleeve can be made of pipes by cold distribution or compression;
- increases the reliability of welded joints due to the lack of materials of welded parts with a significant difference in KTP;
- the large KTR value of the ChS-57 alloy and the requirement for the identical KTP of the bushings and SOFC determine the use of materials based on cobaltites, such as cobaltite-lanthanum-strontium for the SOFC cathode, which have significantly better electrochemical characteristics than, for example, manganite-lanthanum-strontium [14 ], in particular, due to the fact that they, being mixed conductors (with electronic and oxygen conductivity), significantly expand the three-phase boundary, as well as due to higher catalytic activity. This provides either an increase in the efficiency of the SOFC voltage and the assembly as a whole under other identical conditions, or an increase in current density and an improvement in the volumetric characteristics of the assembly;
- a higher strength of cobaltites and the possibility of reducing or even eliminating their open porosity (mixed conductor) increase the strength of the SOFC cathode as a carrier layer, which, as will be shown below, reduces their required thickness, reduces the material consumption of SOFC and their cost.

 In addition, between the ends of the SOFC and the corresponding inner surfaces of the hollow cylinders of the intermediate sleeves of the shells of revolution and the adapter of the end cathode sleeve, inner rings of electrically insulating gas-tight material with a CTE identical to the CTE of the material of the bushings, for example, based on porcelain, with an outer diameter providing an enclosure them into hollow cylinders of the cathode current collectors, with an inner diameter approximately equal to the inner diameter of the hollow cylinders of the anode current collectors, with the shape of the end part identical to the corresponding surface of the bushings, and with a flat opposite end, a high-temperature electrically insulating gas-tight adhesive is placed between the SOFC end face and the ring and between the ring and the corresponding sleeve surface to provide sealing of the SOFC end face and gas density and mechanical strength of the SOFC end face to the ring and a ring with a sleeve, or additionally in a radial clearance between the outer surfaces of the ring and the SOFC directly adjacent to its end face, and the inner surface NOSTA hollow cylindrical cathode current collector, the length of the hollow cylinder anode current collectors are selected from the exception of their ends touching respective inner rings, and the lengths of the hollow cathode current collectors cylinders - with the exception of their ends touch the outer surfaces of adjacent sleeves.

Installing the inner rings and gluing them to the surfaces of the bushings and the end surface of the SOFC, especially with filling the radial gap between the inner surface of the hollow cylinder of the cathode current collector and the ring and the SOFC, increases the manufacturability, mechanical strength and reliability of this connection. The glue can be applied in the form of paste on the end surfaces of the ring and the end face of the cell or installed in the appropriate place in the form of parts, such as washers. The heat treatment of this unit is carried out under compressive axial loads, for example, with the vertical position of the assemblies with support below. Making rings from
electrical insulating material eliminates the short circuit of SOFC electrodes even in the case of possible fluidity of the adhesive, for example, in case of an emergency increase in the operating temperature of the assemblies. Ensuring guaranteed gaps between the ends of the current collectors of the bushings and the inner rings and the outer surfaces of the adjacent bushings by appropriate selection of their lengths eliminates, on the one hand, a short circuit between the SOFC electrodes, and on the other hand, ensures the operation of this SOFC and bushings connection unit under compressive loads in the case of a vertical arrangement of assemblies with a support at the bottom, which increases the reliability of the assembly during operation. The use of inner rings with a flat end facing SOFC unloads SOFC from radial forces.

 In addition, between the ends of the SOFC and the corresponding outer surfaces of the hollow cylinders of the intermediate sleeves of the shells of revolution and the adapter of the end anode sleeve, outer rings of electrically insulating gas-tight material with a CTE identical to the CTE of the material of the bushings, for example, based on porcelain, with an inner diameter that allows installation them to the hollow cylinders of the anode current collectors, with an outer diameter approximately equal to the outer diameter of the hollow cylinders of the cathode current collectors, with of the end part, which is identical to the corresponding surface of the bushings, and a flat opposite end, a high-temperature electrically insulating gas-tight glue is placed between the end face of the SOFC and the ring and between the ring and the corresponding surface of the sleeve to provide sealing of the end face and gas density and mechanical strength of the joint of the end face of the SOFC with the ring and ring with a sleeve, or additionally in a radial clearance between the inner surfaces of the ring and the SOFC directly adjacent to its end face, and the outer surface of the polo of the cylinder of the anode current collector, the lengths of the hollow cylinders of the cathode current collectors are selected with the exception of touching their ends of the corresponding outer rings, and the lengths of the hollow cylinders of the anode current collectors are selected with the exception of touching their ends or the inner surfaces of adjacent bushings, or the corresponding inner rings.

 Installing the outer rings and gluing them to the surfaces of the bushings and the end surface of the SOFC give the same advantages as installing the inner rings.

 In addition, the dimensions and configuration of the outer surface of all outer rings of insulating material or part thereof, for example, mounted on the terminal anode sleeve and parts evenly spaced along the assembly length of the intermediate bushings, are made to ensure the distance of the assemblies in more complex structures, for example in assembly blocks, with the required step, for example, in the form of a spline surface with a diameter along the protrusions of the slots equal to the required step, and with a diameter along the hollows approximately equal to the outer diameter of the hollow qily firewood cathode current bushes.

As indicated above, the use of external spacer rings of insulating material provides vibration and shock resistance of the assemblies, reducing the uneven flow around the assemblies of the KG, electrical insulation of the assemblies from each other and from the parts forming their KP. The use of rings with a spline outer surface reduces hydraulic resistance during the longitudinal flow around KG assemblies in comparison with a cylindrical surface. For the same reason, it is not advisable to set the number of these rings greater than that required under the conditions of ensuring vibration and shock resistance of assemblies
In addition, the anodes of the last or the last SOFC along the anode gas in the assembly and the high-temperature electrically conductive adhesive connecting them to the anode current collectors of the respective bushings are made of materials resistant in both reducing and oxidizing environments, for example, based on a composite material, containing oxides of zirconium, cobalt, yttrium and some other materials, or a mixture of cerium oxide with platinum.

 As shown above, the use of SOFC in assemblies with such anodes and electrically conductive glue provides an increase in the values of limiting efficiency to the assembly flow at stationary loads and transient conditions, i.e. increases the efficiency of the assembly current.

 In addition, the lengths of the last or last SOFC along the anode gas in the assembly are made larger than the lengths of the remaining SOFC in the assembly.

 As shown above, increasing the length of the last SOFC reduces the temperature difference of the SOFC in the assembly. The ability to use SOFC with an increased length in the assembly is provided by the use of bushings with current collectors, which practically do not limit the SOFC length due to the ohmic resistance of the assembly.

 The second of the claimed inventions is illustrated by drawings, where in FIG. 10 shows a longitudinal section of a SOFC assembly; FIG. 11 is a section II in FIG. 10, FIG. 12 is a view K of FIG. 10 (variant), in FIG. 13 is a view A in FIG. 10, in FIG. 14 is a view M of FIG. 10, in FIG. 15 is a view M (variant), in FIG. 16 is a cross section HH in FIG. 14, in FIG. 17 is a cross section OO in FIG. 16, in FIG. 18 is a section PP through FIG. 10, FIG. 19 is a section PP through FIG. 10 (option), FIG. 20 is a sectional view of PP in FIG. 14, in FIG. 21 is a section CC of FIG. fourteen.

 The assembly contains SOFC 27 with a CTE exceeding the CTE of their electrolyte and identical to the CTE of the sleeve material, in the form of a round hollow cylinder with an external supporting cathode 28, an electrolyte 29 and an internal anode 30, the intermediate sleeves 31 in the amount of SOFC reduced by one, in the form of two hollow cylinders larger than 32 and smaller than 33 diameters with the function of cathodic and anodic current collectors with windows 34 for supplying KG and 35 for supplying AG, respectively, articulated by a conical sheath of revolution 36 with the function of current passage and the part forming the assembly AP, end the cathode sleeve 37 and the end anode sleeve 38, made in the form of a hollow cylinder with the function of the cathode current collector 39 and the anode current collector 40 with windows for supplying KG 41 and supplying AG 42, respectively, coupled with adapter 43 and 44, respectively, or with a composite adapter 45 and 46, respectively, consisting of two parts connected by welding, one of which 47 is made of the same alloy as the bushings, and the second 48 is of an alloy with good weldability, inner rings 49 in the amount of SOFC in the assembly, outer rings 50 and outer e spacing ring 51 by the number of the sum of SOFC assembly of electrically insulating material, high temperature adhesives, with which are connected to the bushings SOFC: electrically resistant to 52 KG; - conductive resistant in AG 53; - electrically insulating gas tight in KG and AG 54. As shown in FIG. 10, SOFCs 27 are connected in series electrically and via AG using bushings 31, 37 and 38 and high-temperature adhesives 52, 53 and 54. The terminal SOFC assembly from the side of the terminal anode sleeve 38 is placed between its anode current collector 40 and the cathode current collector 32 of the adjacent intermediate bushings 31. Intermediate SOFC assemblies are placed between the anode current collector 33 of the intermediate sleeve 31 and the cathode current collector 32 of the adjacent intermediate sleeve. The terminal SOFC assembly from the side of the end cathode sleeve 37 is placed between the anode current collector 33 of the adjacent intermediate sleeve and the cathode current collector 39 of the end cathode sleeve 37. The windows 35 and 42 of the anode current collectors 33 and 40 are respectively located opposite the windows 34 and 41 of the cathode current collectors 32 and 39, respectively (see Fig. 11) and are overlapped by the cylindrical surfaces of the SOFC (see Fig. 10, 14, 17). One of the ends of the SOFC is in contact with the inner ring 49 of electrical insulation material having an outer diameter that allows it to be embedded in the hollow cylinder of the cathode current collector 32 or 39, an inner diameter approximately equal to the inner diameter of the hollow cylinder of the anode current collector 33 or 40, the shape of the end surface, identical to the inner surface of the conical shell of revolution 36 or adapter 43 or 45, and the flat shape of the opposite end. The other end face of the SOFC is in contact with the outer ring 50 or with the outer spacer ring 51 of an insulating material with an inner diameter that ensures their installation on the hollow cylinder of the anode current collector 33 and 40, with the shape of the end surface identical to the outer surface of the conical shell of revolution 36 or adapter 44 or 46, and with a flat shape of the opposite end. The outer diameter of the ring 50 is made approximately equal to the outer diameter of the hollow cylinder of the cathode current collector 32 (see Fig. 10, 14, 21), and the outer diameter of the ring 51 is equal to the required spacing of the assemblies in the block (see Fig. 10, 18). In FIG. 19 shows an embodiment of the outer surface of the ring 51 in the form of a slotted surface for spacing the assemblies in the block along a triangular lattice, the diameter along the protrusions of the slots being equal to the required distance of spacing, and along the troughs approximately the outer diameter of the hollow cylinder of the cathode current collector. The lengths of the anode current collectors 33 and 40, respectively, of the intermediate sleeves 31 and the end anode sleeve 38 are made with the exception of touching their ends of the inner rings 49, and the lengths of the cathode current collectors 32 and 39, respectively, of the intermediate sleeves 31 and the end of the cathode sleeve 38 with the exception of touching their ends of the outer rings 50 or outer spacer rings 51 (see FIGS. 10, 14). As shown in FIG. 10, the outer spacer rings 52 are placed on the end anode sleeve 38 and uniformly (through one intermediate sleeve) on the intermediate sleeves 31. In the manufacture of alloy sleeves with good weldability, the adapters of the end sleeves 43 and 44 are made of the same alloy with the possibility of gas-tight and electrically conductive connecting them to the parts of the supply or removal of the AG and current supply to the assembly (not shown in the drawing), for example, by welding (see Fig. 10). In FIG. 12 and 13 show an embodiment of manufacturing composite adapters of end sleeves 45 and 46 in the case of manufacturing sleeves of alloy with limited weldability. These adapters are made of two parts 47 and 48, connected by welding during their manufacture, the first of which is made of the same alloy as the current collectors, and the second of the alloy with good weldability.

 The electrical and mechanical connection of the SOFC anode 30 with the anode current collectors 33 and 40 was carried out using an AG-resistant adhesive 53 placed around the perimeter of windows 35 and 42 with the possible filling of the radial gap between the outer surface of the anode current collector and the inner surface of the SOFC (see Fig. 14, 16 and 17). The electrical and mechanical connection of the SOFC cathode 28 with the cathode current collectors 31 and 37 was carried out using a KG-resistant adhesive 52 located around the perimeter of windows 34 and 41 with the possible filling of the radial gap between the outer surface of the SOFC cathode and the inner surface of the cathode current collector (see Fig. 14, 16 and 17). The sealing of the ends of the SOFC and the cylindrical surfaces closest to them, the gas-tight separation of the AP assembly (inside the assembly) from the gearbox assembly (outside the assembly), the mechanical strength of the SOFC connection with the rings and rings with the surfaces of the bushings adjacent to them, the exclusion of electrical contact between the SOFC electrodes is ensured by electrically insulating gas-tight adhesive 54, resistant in AG and KG, placed (see Fig. 14) between the ends of the SOFC and the rings and rings and the surfaces of the bushings adjacent to them. In FIG. 15 shows a variant of this connection in which said adhesive is additionally placed in radial gaps between the rings and the SOFC on the one hand and the cylindrical surfaces of the current collectors on the other.

 The SOFC assembly can be assembled, for example, as follows. Outer rings 51 or 50 with glue 54 are installed on the anode current collectors of the end anode sleeve and intermediate sleeves, and then the corresponding SOFCs (while their ends and the cylindrical surfaces immediately adjacent to them can be sealed with glue 54). Glue 53 is applied from the free ends of the anode current collectors. After that, preliminary or final heat treatment of these parts of the assembly can be carried out with gluing of the corresponding surfaces. The final assembly is carried out by installing in the indicated parts of the inner rings 49 with glue 54 and the corresponding adjacent parts with the SOFC installed on them and applying glue 52 around the periphery of the windows 34 and 41. After that, the SOFC is assembled in a special fixture undergoing final heat treatment with subsequent quality control, for example leak tightness AP.

 SOFC assembly works as follows. AG through a pipeline (not shown in the drawing) enters the adapter of one of the end sleeves, for example, to the end anode sleeve 38, passes through the assembly assembly and passes through the adapter of the end cathode sleeve 37 and the pipe connected to it (not shown), leaves the assembly assembly . With successive passage, the electrochemical oxidation of AG occurs on the SOFC anodes by diffusive gas exchange through the windows of the anode current collectors 42 and 35 of the bushings and glue 53 (in case of open porosity). KG washing the assembly from the outside (longitudinal, transverse or other flushing) gives off its oxygen through diffusive gas exchange through the windows of the cathode current collectors 34 and 41 of the bushings and glue 52 (in case of open porosity). The stream of electrons from the VTZ battery through the current lead (not shown) goes to the adapter of the end cathode sleeve 37 and then through the cathode current collector 39 of this sleeve to the cathode 28 connected to this SOFC collector 27. Oxygen is ionized in the cathode and the electrons are transferred by oxygen ions through the electrolyte 29 to the anode 30, where electrochemical oxygen reduction (AG oxidation) takes place, and an electron beam with an increased voltage enters the anode current collector 33 of the adjacent intermediate sleeve 31 and along it cathode current collector 32. Passing sequentially all the assembly of SOFC, the electron beam assembly with voltage supplied to the anode current collector of the anode terminal 40 of the sleeve 38 and then through the adapter sleeve and that the current lead (not shown) - to the battery VPP. Without taking into account the spatial location of the SOFC assembly, its operation will not change even if the AG movement in the assembly is opposite to that discussed above. In the case of using SOFCs of different lengths, for example, the increased length of the last or last SOFCs along the AG in the assembly of the length of the current collectors of their respective terminal and intermediate bushes and the placement of windows in them, they are also chosen large with the exception of touching their ends of the corresponding rings and ensuring overlapping of the cells of the SOFC.

 SOFCs with different composition of their anodes can be used in the assembly, for example, in the last or the last SOFC along the AG, anodes of materials resistant to both reducing and oxidizing media were used in the assembly. In this case, the adhesive 53 connecting them to the corresponding anode current collectors of the bushings is also made of materials resistant in these environments.

 The proposed design of the assembly of SOFC with KTR exceeding the KTR of their electrolyte, in comparison with the prototype, has improved weight and size characteristics and manufacturability, high values of efficiency in current and voltage, rigidity, strength and reliability, vibration and shock resistance.

 The third of the alleged inventions relates to SOFC, the most important component of the SOFC assembly, namely, SOFC with a CTE exceeding the CTE of their electrolyte.

 Three main types of SOFC structures are known: tubular, planar and monolithic. The tubular structure, in turn, is divided into SOFC with a supporting (thick) electrolyte and thin electrodes, for example, those discussed above in the patent [13], with a supporting inner tube and a thin cathode, electrolyte and anode deposited on its outer surface, for example, of a design firms Westinhouse [15] and Mitsubishi [16], and with a supporting inner cathode and thin electrolyte and anode deposited on its outer surface, see, for example, [3]. The latter design is the closest analogue of the alleged invention.

 All three of these main types of SOFC designs have KTP identical to (close) KTP of their electrolytes. Indeed, planar and tubular SOFCs with supporting electrolytes obviously have KTPs that are almost equal to the KTPs of their electrolytes. In a tubular SOFC with a supporting internal cathode, the cathode material is selected so that its CTE is identical to the CTE of the electrolyte, since otherwise the integrity of the SOFC in the entire temperature range of its operation is not ensured. For example, in the case when the CTE of the cathode exceeds the CTE of the electrolyte, when the SOFC is cooled below the temperature of its manufacture, the radial and axial dimensions of the cathode decrease more than the electrolyte. As a result of this, and beyond the actual dependence on the CTE of the thin anode, axial and circumferential compressive forces act on the electrolyte. The circumferential forces tend to tear off the cylindrical surface of the electrolyte from the cathode, since their resultant due to the convexity of the surface is directed along the external normal, and tensile radial stresses arise in the transition zone between the electrolyte and the cathode, which, together with the shear stresses caused by axial forces in it, lead to further lowering the temperature (the indicated forces and voltages increase in absolute value) to the minimum operating temperature of the SOFC (forces and voltages ostigayut maximum values) to break bonds between the electrolyte and the cathode (in the loss of the three-phase boundary) and destruction (peel strength) of the thin electrolyte layer together with a thin layer of the anode. Similar phenomena are observed in the layers of glaze or enamel deposited on ceramics or metal, respectively, if the CTE of the ceramic or metal exceeds the CTE of the glaze or enamel by more than a few percent [18]. In the case where the KTR of the carrier cathode is less than the KTR of the electrolyte, with the same cooling of the SOFC, the radial and axial dimensions of the cathode decrease less than the electrolyte. This leads (also regardless of the thermal expansion coefficient of the thin anode) to the appearance of tensile circumferential and axial stresses in the cylindrical layer of the electrolyte, under the influence of which cracks form in the electrolyte, its gas density is lost and SOFC is destroyed due to a significantly lower value of the allowable tensile stresses of the ceramic compared to the allowable compression stress. Similar destruction occurs in the layers of glaze or enamel, if the CTE of the ceramic or metal is less than the CTE of the glaze or enamel [18]. In planar SOFC designs with a supporting cathode and thin layers of electrolyte and anode, the requirement for the identity of the thermal expansion coefficient of the cathode and electrolyte also exists. For example, in the case where the CTE of the cathode exceeds the CTE of the electrolyte, when cooling the SOFC, the dimensions of the cathode decrease more than the electrolyte. As a result of this, and outside of the practical dependence on the thermal expansion coefficient of the thin anode, biaxial compressive stresses appear in the electrolyte, and tensile stresses arise in the cathode, under the influence of which the SOFC form is distorted (if the cathode thickness is insufficient), the flat SOFC becomes convex towards the electrolyte. Compressive stresses due to the convexity of the surface and shear stress cause a break in the bonds between the electrolyte and the cathode and destruction (peeling) of the electrolyte together with a thin layer of the anode. In the case when the KTP of the supporting cathode is less than the KTP of the electrolyte, with the same cooling of the SOFC, the dimensions of the cathode decrease less than the electrolyte. This leads (also regardless of the thermal expansion coefficient of the thin anode) to the appearance of biaxial tensile stresses in the electrolyte and compressive stresses in the cathode, and the SOFC form is distorted - the flat SOFC becomes concave toward the electrolyte. Biaxial tensile stresses cause cracks in the electrolyte and loss of its gas density. A design variant of planar SOFC with a supporting cathode and anode and a thin electrolyte is also possible. In this design, the KTP of the cathode and anode should be identical, since their difference leads, as indicated above, to the loss of flatness of the SOFC. However, this requirement is practically impracticable, which is associated with the fabrication of SOFC in an oxidizing atmosphere due to the persistence of cathode materials, for example, cobaltites and manganites-strontium-strontium in reducing or neutral media. Therefore, the anode is made from a mixture of metal oxides, for example, nickel oxide, with an electrolyte, and its reduction to nickel-cermet is performed at the first start of the VT ECG. The recovery process is accompanied by a change (increase) in the CTE of the anode. But even when solving this problem, the thermal expansion coefficient of the anode and cathode should be identical to the thermal expansion coefficient of the electrolyte, since if they differ, for example, when the thermal expansion coefficient of the cathode and anode exceeds the thermal expansion coefficient of the electrolyte during the SOFC cooling, shear stresses arising in the transition zones in the absence of forces pressing the layers together to a friend due to the planar design of SOFC, lead to the destruction of transition zones and SOFC as a whole.

 The technical result of the third of the group of alleged inventions is the creation of a SOFC with a CTE exceeding the CTE of its electrolyte and identical, for example, to the CTE of the material of the sleeves, with the help of which the SOFCs are assembled into SOFC assemblies, as well as the possibility of using various materials in the anode that are most optimal from the point of view SOFC operations in various parts of the anode space of the SOFC assembly, for example, in the zones of hydrocarbon gas conversion in the anode space, high and low concentrations of combustible components in it, and free oxygen in the anode space.

где S_П, S_Э, S_В - толщина наружного электрода, электролита и внутреннего электрода соответственно;
t_П, t_М - температура изготовления ТОТЭ и минимальная температура его эксплуатации соответственно,
α_н, α_э, α_в - средний КТР материала наружного электрода электролита и внутреннего электрода соответственно в диапазоне температур от t_М до t_П;
E_Э, E_В - модуль упругости материала электролита и внутреннего электрода соответственно при температуре t_М;
μ - коэффициент Пуассона;

допускаемое напряжение при растяжении материала наружного электрода при температуре t_М,
электролит которого выполнен тонким с обеспечением газоплотности, например, толщиной 15...50 мкм, а внутренний электрод которого выполнен из материала с КТР, меньшим КТР материала наружного электрода на величину, обеспечивающую его прижатие к внутренней поверхности электролита в указанном диапазоне температур, например, не менее 1,5%, с толщиной, обеспечивающей устойчивость сжатых электролита и внутреннего электрода в указанном диапазоне температур, например, превышающей величину, определенную по формуле
S_в> m•r•[(α_н-α_в)•(t_п-t_м)]^0,666, (2)
где m - коэффициент, определяемый опытным путем;
r - средний радиус ТОТЭ;
но не менее величины, определенной по формуле
S_в> n•S_э•(α_н-α_э)/(α_н-α_в), (3)
где n - коэффициент, определяемый опытным путем,
при этом изготовление ТОТЭ, например, методом спекания произведено при температуре выше температуры изготовления сборки ТОТЭ и максимальной температуры ее эксплуатации в составе ВТ ЭХГ.To achieve the technical result, a SOFC containing an electrolyte, for example, from zirconia stabilized with yttrium oxide, and the anode and cathode electrodes located on its opposite sides, according to the proposed invention, have the shape of a round hollow cylinder, the outer electrode of which is made of a material with a CTE exceeding KTP of its electrolyte and identical, for example, KTP of the material of the bushings connecting the SOFC in assemblies and made of heat-resistant or heat-resistant alloys, and is equipped with a bearing function layer with ensuring the integrity of SOFC in the temperature range from the temperature of its manufacture to the minimum operating temperature, for example, with a thickness exceeding the value determined by the formula

where S _P , S _E , S _In - the thickness of the outer electrode, electrolyte and inner electrode, respectively;
t _P , t _M - SOFC manufacturing temperature and its minimum operating temperature, respectively,
α _n , α _e , α _in - the average CTE of the material of the outer electrode of the electrolyte and the inner electrode, respectively, in the temperature range from t _M to t _P ;
E _E , E _B - the modulus of elasticity of the electrolyte material and the inner electrode, respectively, at a temperature t _M ;
μ is the Poisson's ratio;

permissible tensile stress of the outer electrode material at a temperature t _M ,
the electrolyte of which is made thin to ensure gas density, for example, with a thickness of 15 ... 50 μm, and the inner electrode of which is made of a material with a CTE less than the CTE of the material of the outer electrode by an amount that ensures it is pressed against the inner surface of the electrolyte in the specified temperature range, for example, at least 1.5%, with a thickness that ensures the stability of the compressed electrolyte and internal electrode in the specified temperature range, for example, exceeding the value determined by the formula
S _in > m • r • [(α _n -α _in ) • (t _p -t _m )] ^0.666 , (2)
where m is the coefficient determined empirically;
r is the average radius of the SOFC;
but not less than the value determined by the formula
S _in> n • S _e • (α _e -α _n) / (α _N -α _c) (3)
where n is a coefficient determined empirically,
in this case, the production of SOFC, for example, by sintering, was performed at a temperature above the temperature of manufacture of the SOFC assembly and the maximum temperature of its operation as part of the VT ECG.

 The temperature of SOFC manufacturing is understood as the temperature of the technological process of SOFC manufacturing at which the stresses in SOFC are zero. For example, in the manufacture of SOFC by co-sintering of a preformed raw three-layer SOFC, a monolithic layered structure is formed with transition zones between the layers providing the necessary three-phase boundaries and electrical contacts. The maximum temperature of this process, which occurs at an almost zero stress state of SOFC, is the temperature of SOFC fabrication.

 The minimum operating temperature of SOFC is understood as the minimum temperature at which SOFC can be after its manufacture, for example, during storage of SOFC, SOFC assemblies removed from the action of VT ECG.

 The temperature of manufacture of the SOFC assembly is understood as the maximum temperature of the technological process of manufacturing the SOFC assembly.

 The maximum operating temperature of the SOFC assembly is understood as the maximum temperature of the SOFC during assembly operation as part of the VT ECG.

 The fulfillment of the above conditions ensures the integrity of the SOFC in the temperature range of its operation from the manufacturing temperature to the minimum operating temperature, as well as the ability to generate electric current. Indeed, the shape of the SOFC in the form of a round hollow cylinder, the function of the supporting layer performed by the outer electrode, the excess of its KTP over the KTE of the electrolyte and the internal electrode provide at temperatures lower than the temperature of the SOFC, the inner cylindrical surface of the outer electrode is pressed against the outer surface of the electrolyte and the inner surface of the latter to the outer surface of the inner electrode, compression of the electrolyte and the inner electrode in the radial and axial directions, occurrence in the transition s zones between layers of compressive radial forces and axial friction forces, which, together with the axial forces from the shear stresses provide compatibility of deformations of the three layers, i.e. SOFC integrity, and maintaining the structure of transition zones, and therefore the ability to generate electric current. In this case, circumferential and axial tensile stresses arise in the outer electrode, and similar compressive stresses arise in the electrolyte and in the inner electrode. At the minimum operating temperature of SOFC, the indicated forces and voltages reach maximum values in absolute value.

 To ensure the function of the carrier layer performed by the outer electrode, i.e. its strength under the action of tensile circumferential and axial stresses, the thickness of the outer electrode must be selected in a certain way, for example, exceed the value determined by the above formula (1). This formula is obtained from the analysis of the stress-strain state of a three-layer round thin-walled cylindrical shell under the action of thermal loads arising from the difference in the CTE of its layers. It is customary to: firstly, the temperature of the layers are the same; secondly, the stresses in the layers at the temperature of SOFC production are zero; thirdly, the radial and axial deformations of the external electrode under the action of the stresses arising in it are equal to zero, i.e., all deformation under the influence of thermal loads is perceived by the electrolyte and the internal electrode, which is a safety factor; fourthly, destructive stresses are tensile stresses in the outer electrode, and compressive stresses in the electrolyte and in the inner electrode, which arise in this case, are lower than permissible. The last assumption is justified by the fact that in ceramics the tensile tensile stresses are significantly (about 10 times) lower than the compressive tensile stress and the first weakly depends on temperature, and the second increases significantly with decreasing temperature (see, for example, [10]). In addition, the electrolyte, in which the maximum compressive stresses arise due to the excess of the KTP difference of the external electrode and the electrolyte, over the difference of the KTP of the external and internal electrodes, is under conditions of comprehensive compression, which significantly increases the permissible voltage. The magnitude of the allowable stress when tensile of the outer electrode depends on the composition of the material, porosity, technology of manufacturing SOFC, the selected margin of safety and is determined empirically. As indicated above, it weakly depends on temperature, nevertheless, the value of the allowable voltage in formula (1) is taken at the minimum operating temperature of the SOFC, when the voltages in the external electrode have maximum values. The margin of safety is also selected taking into account the possible temperature difference of the layers during the operation of the SOFC as part of the VT ECG, for example, in the modes of input and output of the VT ECG from action.

 As can be seen from formula (1), the required thickness of the outer electrode increases with increasing thickness of the electrolyte under other identical conditions. Therefore, it is advisable to choose the thickness of the electrolyte minimum, provided that other requirements are met, for example, gas density, electrical characteristics of SOFC, its life, etc., for example, 15 ... 50 microns.

 The KTE value of the material of the inner electrode is selected, as indicated above, from the condition of ensuring that the inner cylindrical surface of the electrolyte is pressed against the outer surface of the inner electrode in the entire operating temperature range of the SOFC, necessary to maintain the structure of the transition zone between them, as well as to ensure the stability of the compressed electrolyte layer. In other words, the KTE difference between the outer and inner electrodes, referred to the KTP value of the outer electrode, must be positive and not only prevent the formation of a radial gap between the electrolyte and the inner electrode, but also a certain radial pressure between them. If the KTR of the external and internal electrodes is equal, the occurrence of this gap is due to the deformation of the external electrode unaccounted for in the formula (1) under the action of tensile stress. The magnitude of this deformation is small due to the small size of the allowable tensile stress of the outer electrode compared to its elastic modulus. To the point, this deformation somewhat reduces the thermal expansion coefficient of SOFC compared with the thermal expansion coefficient of the material of the outer electrode, to 1%, as calculations show. The occurrence of radial clearance is prevented by an increase in the thickness of the electrolyte under the action of compressive circumferential and axial stresses, as well as a smaller KTP of the electrolyte. However, calculations show that this does not compensate for the occurrence of a gap due to deformation of the outer electrode. Thus, in order to eliminate the radial gap between the electrolyte and the inner electrode and create a radial pressure between them, it is necessary that the CTE of the internal electrode is less than the CTE of the outer electrode by more than 1.5%. This condition leaves a fairly wide opportunity in the choice of materials for the internal electrode. However, as can be seen from formula (1), an increase in this difference leads to an increase in the required thickness of the outer electrode. Therefore, it is advisable to choose the material of the inner electrode with the CTE closest to the maximum value of the indicated allowed range of its change, provided that other requirements for the inner electrode are provided, for example, electrical characteristics, etc.

The required thickness of the inner electrode is determined from the condition of ensuring stability and, consequently, the integrity of the thin layers of the electrolyte and the inner electrode compressed by the outer electrode. The most studied cases are the loss of stability of a cylindrical shell under the influence of external pressure of a liquid or gas, when the loss of stability is accompanied by a change in the shape of the shell. In this case, the external pressure on the electrolyte and the internal electrode creates an external electrode under the action of tensile stresses, i.e. not losing its shape. This, along with transition zones between the layers interlocking them, eliminates the loss of the overall stability of the cylindrical shell, and the possible destruction of the compressed electrolyte and the internal electrode occurs in the form of a loss of local stability (local peeling), i.e. at significantly higher loads than with the loss of overall stability. Formula (3) determines the required thickness of the internal electrode, based on ensuring the stability of the electrolyte. At its conclusion, it was assumed that to ensure the stability of the electrolyte, it is enough that the radial pressure acts on the electrolyte from the side of the internal electrode, the value of which is part of the radial pressure acting from the side of the external electrode. The radial pressure from the outer electrode is determined by the formula
P _n = (α _n -α _e ) • (t _p -t _m ) • E _e • S _e / [(1-μ) • r] + P _in , (4)
where P _N , P _{B is the} radial pressure from the side of the outer and inner electrodes, respectively, the last of which is determined by the formula
P _in = (α _n -α _in ) • (t _p -t _m ) • S _in • E _in / [(1-μ) • r] (5)
Having designated the ratio of pressure Р _H to P _В through K, after transformation (4) and (5), we obtain formula (3), where n = K / (K - 1). The value of K depends on the deviations of the inner surface of the outer electrode from the round cylinder, on the strength of the transition zones between the electrolyte and the electrodes, on the thickness and material of the electrolyte, the radius of the SOFC and some other factors, its value lies in the range of 5.0 ... 50.0 ( n in the range of 0.02 ... 0.25) and is specified for a specific case empirically. Formula (2) determines the required thickness of the internal electrode, based on ensuring its own stability under the influence of external pressure from the electrolyte. When deriving it, we used the dependences of calculating the stability of a cylindrical shell given in [17]. In accordance with these dependences, the critical stress at which the overall stability is lost is determined by the formula
σ _cr = 1.3E _in • 2r / L • (S _in / 2r) ^1.5 , (6)
where L is the length of the shell.

The circumferential and axial stresses in the layer of the inner electrode under the influence of thermal loads are equal and are determined by the formula
σ _in = (α _n -α _in ) • (t _p -t _m ) • E _in / (1-μ). (7)
To ensure the stability of the shell σ _in should be less than σ _cr . After transformation (6) and (7), we obtain formula (2), where
m = 2 / [1.3 • 2 • r (1-μ) / L] ^0.666 ,
which with a ratio of 2r / L ≅ 2 has a value of approx. 4. In the case under consideration, for the reasons stated above, the value of m is substantially less than four. It depends on the deviations of the surface of the electrolyte from the circular cylinder, on the strength of the transition zones between the electrolyte and the electrodes, on the material of the internal electrode and some other factors, its value is approximately an order of magnitude lower and is specified experimentally. The thickness of the inner electrode is selected as the largest maximum of the values determined by formulas (2) and (3). As can be seen from formula (1), an increase in the thickness of the inner electrode, as well as of the electrolyte, leads to an increase in the required thickness of the outer electrode, although to a lesser extent than an increase in the thickness of the electrolyte due to the smaller difference in the CTE of the outer and inner electrodes compared to the difference in the CTE of the outer electrode and electrolyte. Therefore, it is advisable to take the thickness of the inner electrode to be minimal within the specified resolution range of its change, provided that other requirements for the inner electrode are provided, for example, ensuring the required conductivity along the inner electrode.

 The temperature of SOFC fabrication is assumed to be higher than the maximum temperature of the SOFC assembly and the maximum temperature of its operation as part of the VT ECG, as this excludes cases when tensile stresses arise in the transition zones between the electrolyte and electrodes, as well as in the electrolyte and in the internal electrode, t i.e., cases when a violation of their integrity may occur.

If during the operation of SOFC as part of the VT ECM, some relaxation of the stresses in the SOFC occurs due to the high temperatures at the working loads of the VT ECCH, this will lead to a decrease in the temperature at which the voltages in the SOFC are zero, i.e. to a decrease in temperature t _P. In this case, the inequalities in formulas (1) and (2) are preserved and satisfied with a large margin.

 In addition, the outer supporting electrode is equipped with a cathode function, and the inner electrode is equipped with an anode function.

 The creation of a SOFC with a supporting external electrode with a cathode function and an internal electrode with an anode function and their use in SOFC assemblies and SOFC assembly blocks determines, as indicated above, the advantages of these structures and the VTZ battery as a whole. Moreover, in the case of the use of SOFC in assemblies with an external electrode with anode function, their integrity can hardly be ensured. This is due to the fact that a specific feature of a number of SOFC manufacturing methods and a SOFC assembly manufacturing method is heat treatment in an oxidizing atmosphere due to the instability of cathode materials, for example, cobaltites and manganites-lanthanum-strontium, in reducing or neutral media. Therefore, in the initial mass for the manufacture of the anode, metals, for example, nickel or cobalt, are in the form of oxides, and their reduction and transition to a working state occurs in the manufactured VTZ battery during the first start-up by supplying, for example, hydrogen to the AP. When recovering the anode material, it is necessary to change (increase) the KTE and, therefore, the KTE of the SOFC, if the anode is a carrier, and to ensure the identity of the KTE of the SOFC and the bushings, which primarily determines the integrity of the assembly, is almost impossible during its manufacture and subsequent operation. In the case of an SOFC internal electrode with anode function, the material of which is presented, as shown above, the CTE requirements are less stringent (the CTE value is limited only from above - it should be slightly less than the CTE of the cathode material), the SOFC integrity at the indicated change in the CTE of the anode during fabrication SOFC and SOFC assemblies and their operation is ensured by an appropriate choice of the cathode thickness, namely, the cathode thickness is selected when the anode is thermally modified by the KTE, and the anode material is selected so that its KTP after reduction was enshe CTE of the anode by an amount not less than 1.5%. As for the identity of the KTE of the SOFC and the assembly sleeves, it is ensured by the choice of the cathode material, the KTE of which does not change during the indicated restoration of the anode in the first start of the SOFC battery.

 In addition, the internal electrode - anode is made of materials that are stable in both reducing and oxidizing media, for example, based on a composite material containing oxides of zirconium, cobalt, yttrium and some other materials, or a mixture of cerium oxide with platinum.

 As shown above, the use of SOFC with such anodes in the assemblies as the last or last along the AG in the assembly of elements provides an increase in the current efficiency of the assemblies, assembly units, and the VTZ battery as a whole, and also improves the maneuverability of the VT ECG. The possibility of using such materials for the anode, which is the SOFC internal electrode, is due to the SOFC design, which provides a limitation in the CTE only from above, as indicated above.

 The third of the group of alleged inventions is illustrated by drawings and an example of calculation of SOFC. In FIG. 22 shows a longitudinal section of a SOFC, and FIG. 23 is a cross-section TT in FIG. 22, in FIG. 24 is a view of U in FIG. 22. The cylindrical SOFC contains an external carrier electrode with cathode function 55, a thin gas-tight electrolyte 56, and an internal electrode with anode function 57.

 An example of the calculation of SOFC with a CTE exceeding the CTE of its electrolyte, with an external supporting electrode with a cathode function and an internal electrode with an anode function.

 1. The source data.

1.1. The average KTR of the cathode material required by the condition of identity with the sleeve material is α _n = 16.3 • 10 ^-6 1 / K.
1.2. The average CTE of the electrolyte material α _e = 10.0 • 10 ^-6 1 / K.
1.3. SOFC fabrication temperature t _P = 1573K.

1.4. The minimum operating temperature of SOFC is t _M = 273K.

1.5. The thickness of the electrolyte S _E = 30 • 10 ^-6 m

1.6. The elastic modulus of the electrolyte material at a temperature t _M E _E = 1.7 • 10 ⁵ MPa.

1.7. The elastic modulus of the anode material at a temperature of t _M E _B = 1.7 • 10 ⁵ MPa.

 1.8. Poisson's ratio μ = 0.3.

1.9. Permissible tensile stress of the cathode material at a temperature of t _M [σ _n ] = 50 MPa.

1.10. The average SOFC radius r = 10 • 10 ^-3 m.

 2. Calculation.

2.2. Примем величину КТР материала анода в восстановленном состоянии
α $\genfrac{}{}{0ex}{}{\text{в}}{\text{в}}$ = 15,8•10^-6 1/K
Это может быть обеспечено составом материала, например содержанием никеля в никель-кермете.2.1. The maximum allowable KTR of the anode material

2.2. We take the KTR value of the anode material in the reduced state
α $\genfrac{}{}{0ex}{}{\text{in}}{\text{in}}$ = 15.8 • 10 ^-6 1 / K
This can be ensured by the composition of the material, for example, the nickel content of the nickel cermet.

2.3. Let the KTP of the anode material in the oxidized state be
α $\genfrac{}{}{0ex}{}{\text{o}}{\text{in}}$ = 14.5 • 10 ^-6 1 / K
2.4. Using the formula (2), we determine the required thickness of the anode from the condition of ensuring its stability:
- in an oxidized state
S $\genfrac{}{}{0ex}{}{\text{in}}{\text{in 1}}$ ≥ m • r • [(α _n -α $\genfrac{}{}{0ex}{}{\text{o}}{\text{in}}$ ) • (t _p -t _m )] ^0.666 ,
where we take m = 0.4
S _B1 ^O ≥ 0.4 • 10 • 10 ^-3 [(16.3 • 10 ^-6 -14.5 • 10 ^-6 ) • (1573-273)] ^0.666 = 71 • 10 ^-6 m;
- in a restored state
S _B1 ≥ 0.4 • 10 • 10 ^-3 [(16.3 • 10 ^-6 -15.8 • 10 ^-6 ) • (1573-273)] ^0.666 = 30.1 • 10 ^-6 m.

2.5 Using the formula (3), we determine the required thickness of the anode from the conditions for ensuring the stability of the electrolyte:
- in the oxidized state of the anode
S $\genfrac{}{}{0ex}{}{\text{o}}{\text{in 2}}$ ≥ n • S _e • (α _n -α _e ) / (α _n -α $\genfrac{}{}{0ex}{}{\text{o}}{\text{in}}$ ),
where we take n = 0.15.

S _B2 ^o ≥ 0.15 • 30 • 10 ^-6 (16.3 • 10 ^-6 -10 • 10 ^-6 ) / (16.3 • 10 ^-6 -14.5 • 10 ^-6 ) = 15.75 • 10 ^-6 m.

- in the restored state of the anode
S _B2 ^V ≥ 0.15 • 30 • 10 ^-6 (16.3 • 10 ^-6 -10 • 10 ^-6 ) / (16.3 • 10 ^-6 -15.8 • 10 ^-6 ) = 56.7 • 10 ^-6 m;
2.6. Find the maximum value of the required thickness of the anode
S _В ^М = max (S _В1 ^О , S _В1 ^В , S _В2 ^О , S _В2 ^В = 71 • 10 ^-6 m.

2.7. Let, based on other requirements, for example, ensuring electrochemical and electrical characteristics, the anode thickness is chosen equal to
S _B = 80 • 10 ^-6 m.

- в процессе эксплуатации ТОТЭ (анод находится в восстановленном состоянии)
S_Н ^В≥(1573-273)•[(16,3•10^-6-10• 10^-6)•1,7•10⁵•30•10^-6+ (16,3•10^-6-15,8•10^-6)•1,7•10⁵• 80•10^-6]/[(1-0,3)•50]=1,45•10^{-3 м}
Таким образом, требуемая толщина катода для обеспечения целостности ТОТЭ как в процессе изготовления, так и эксплуатации в составе ВТ ЭХГ должна быть не менее 2,1 мм.2.8. Using the formula (1), we determine the required cathode thickness from the condition for ensuring the SOFC integrity:
- during the manufacturing process of SOFC and SOFC assemblies (the anode is in an oxidized state)

- during operation of SOFC (the anode is in a restored state)
S _N ^B ≥ (1573-273) • [(16.3 • 10 ^-6 -10 • 10 ^-6 ) • 1.7 • 10 ⁵ • 30 • 10 ^-6 + (16.3 • 10 ^-6 -15 , 8 • 10 ^-6 ) • 1.7 • 10 ⁵ • 80 • 10 ^-6 ] / [(1-0.3) • 50] = 1.45 • 10 ^{-3 m}
Thus, the required thickness of the cathode to ensure the integrity of the SOFC both in the manufacturing process and in operation as part of the VT ECG should be at least 2.1 mm.

 Compared with the prototype, the proposed design of SOFC provides a significant increase in its KTP to values when it is possible to use technological heat-resistant alloys with good weldability as a structural material of the assembly, block and VTZ as a whole. It eliminates the requirement of the identity of the KTP of the materials of the electrodes and electrolyte, which, due to the expansion of the range of materials for the anode, ensures the creation of SOFCs that are optimal for working in various parts of the assembly assembly.

 The proposed group of inventions provides the creation of VT ECG with significantly improved manufacturability, weight, size, electrical, resource and maneuverability characteristics.

Sources of information taken into account when preparing the application:
1. US patent N 5143800.

 2. US Patent N 5047299.

 3. Br. Riler, Solid oxide fuel cells - the next stage, Journal of Power Sources, 29 (1990), 223-237.

 4. B.N. Artemova, M.A. Questions of atomic science and technology. Ser. Nuclear and Hydrogen Energy and Technology, 1982, no. 2 (12), p. 87-93.

 5. Yu. A. Dushin, N. A. Medvedev, N. N. Gribov et al. Technological properties of the KhN55MVTs alloy as applied to high-temperature equipment. Questions of atomic science and technology. Ser. Atomic - Hydrogen Energy and Technology, 1988, no. 1, p. 94-95.

 6. S.I. Volodin, Yu.A. Dushin, Yu.I. Zvezdin et al. Encouragement of VT-400 metal materials in a process loop environment. Questions of atomic science and technology. Ser. Atomic - Hydrogen Energy and Technology, 1988, no. 1, p. 96-97.

 7. Materials for metal components of the installation with high temperature fuel cells. Application 578854 EPO, MKI N 01 M 8/02, C 22 C 14/00, decl. 16.7.92.

 8. Materials for metal components of the installation with high temperature fuel cells. Application 578855 EPO, MKI N 01 M 8/02, C 22 C 32/00. Claim 16.7.92.

 9. Marochnik steels and alloys. Ed. V.G. Sorokina, M. "Mechanical Engineering", 1989, 640 p.

 10. High temperature gas electrolysis. M.V. Perfiliev, A.K. Demin, B.L. Kuzin, A.S. Lipilin. - M: Science, 1988 -232 p.

 11. Ionica solid: Sat. scientific works. Ekaterinburg: UIF "Science", 1993.

 12. The current state of the theory of thermal and oxidative pyrolysis of methane. Evlanov S.F., Lavrov N.V. - In: Scientific principles of the catalytic conversion of hydrocarbons. K., 1977, p. 210-232.

 13. US Patent N5338623.

 14. Takeda Y., Kanna R, Noda M., Tamida Y., Yamamoto O., J. Electrochem. Soc. L987. V 134. p. 2556.

 15. EPO. Z.N 0055011, class H 01 M 8/12, op. 06/30/82. High temperature solid electrolyte fuel cell.

 16. EPO, s. N0180538, class H 01 M 8/12, op. 7.05.86. Solid electrolyte fuel cell and method for its manufacture.

 17. Standards for calculating the strength of elements of reactors, steam generators, vessels and pipelines of nuclear power plants, experimental and research nuclear reactors and installations. Moscow, Metallurgy, 1973, p. 408.

 18. U.D. Kingeri. Introduction to Ceramite, M., Stroyizdat, 1967, p. 499.

Claims (16)

 1. Block assemblies of solid oxide fuel cells (SOFC) with a coefficient of thermal expansion (KTE) exceeding the KTE of their electrolyte, containing many SOFC, cathode and anode current leads, electrodes, parts forming the cathode and anode spaces, inlets and outlets of the cathode and anode gas, and attachment points, characterized in that it is equipped with at least two assemblies containing at least two SOFCs with a CTE exceeding the CTE of their electrolyte, in the form of a round hollow cylinder, the outer electrode of which has the functions of a carrier with cathode and cathode, and the inner electrode - the function of the anode, intermediate bushings in the amount of SOFC reduced by one, and end anode and cathode bushings with current collectors made of a heat-resistant or heat-resistant alloy with KTR identical to KTE of SOFC, for example, from ChS- 57 or a high-chromium alloy, with the help of which high-temperature SOFC adhesives in assemblies are connected in series electrically and by anode gas with the possibility of gas-tight and electrically conductive connection of end sleeves with sludge supply parts and removal of the anode gas and with the assembly conductors, for example, by welding, and external spacer rings of electrical insulation material installed outside of all the intermediate sleeves and the end anode sleeve or part of the sleeves, for example, the end anode sleeve and parts of the intermediate sleeves evenly spaced along the assembly length , and having the dimensions and shape of the outer surface, ensuring the spacing of the assemblies in the block with the required pitch, the anode gas supply and exhaust chambers in the form of a tube plate with a cover, interconnected to ensure gas tightness and electrical conductivity, for example, by welding, and also with the ability to connect to the last part of the supply or removal of anode gas and (or) current supply to the unit with gas tightness and (or) electrical conductivity, for example, by welding, bent tubes over twice the number of assemblies with an outer diameter approximately two times smaller than the required step for spacing the assemblies in the block, with the values of their folding, providing, together with the location of their corresponding the holes in the tube plates of the anode gas supply and removal chambers, the required distance of spacing, and the cover covering the assembly, forming the cathode space of the block during longitudinal movement of the cathode gas along the assemblies with its inlet and outlet from the block in the vicinity of the chambers, with the camera mounts that limit their movement along the axis of the block, while the chambers, bent tubes and the casing with the mounting parts of the chambers are made of heat-resistant alloy with good weldability, for example, of ChS-57 alloy, the assemblies are connected in parallel electrically and nodnomu gas homonymous anode terminal bushings with the tube plates of anode gassing or removal chambers corresponding curved tubes ensuring gas tightness and electrical connections, such as by welding, between the parts and fixing cameras and cameras installed electrical insulators.  2. The block according to claim 1, characterized in that the axis of the block is located vertically in space, and the mounting parts of the anode gas supply or exhaust chamber are located in the lower part of the casing with the exception of moving the lower chamber downward relative to the casing.  3. The block according to claim 2, characterized in that the anode gas is supplied and removed to the upper chamber and from the lower chamber, respectively.  4. The block according to claim 3, characterized in that it is equipped with assemblies, the inner diameter of which is made to provide the required value of the uneven efficiency in the current of the assemblies in the block, for example, exceeding a value proportional to the cubic root of the product of the sum of the assembly length and the projection length on the axis block of the lower bent tube to the average assembly current density through SOFC electrolytes at maximum load, with a proportionality coefficient increasing with increasing concentration in the anode gas at the inlet to the block of non-combustible components, with an increase in the difference in hydraulic and electrical characteristics of the assemblies, due to the technology of their manufacture, and with a decrease in the required value of the unevenness of the efficiency in the current of the assemblies in the block.  5. The block according to claim 4, characterized in that it is equipped with assemblies in which the anode of the last or last SOFC along the anode gas in the assembly and the high-temperature electrically conductive adhesive connecting them to the anode current collectors of the respective bushings are made of materials resistant as in reducing and in oxidizing environments, for example, based on a composite oxide material containing oxides of zirconium, cobalt, yttrium and some other metals, or a mixture of cerium oxide and platinum.  6. Block according to any one of claims 1 to 5, characterized in that in it the cathode gas inlet to the cathode space is made in the region of the anode gas outlet chamber, and the outlet is in the region of the anode gas inlet chamber, i.e. the movement of the anode and cathode gases is organized by a countercurrent.  7. The unit according to claim 6, characterized in that it is provided with assemblies in which the lengths of the last or last SOFC along the anode gas in the assembly are made larger than the lengths of the remaining SOFC in the assembly.  8. The assembly of SOFCs with KTE exceeding the KTE of their electrolyte, containing many SOFCs, intermediate sleeves in terms of the number of SOFCs decreased by one, the end cathode and anode bushings with which SOFCs are connected in series electrically and through the anode gas and it is possible to connect parts to the assembly inlet and outlet of anode gas and down conductors, characterized in that it is equipped with at least two SOFCs with a CTE exceeding the CTE of their electrolyte and identical to the CTE of the material of the bushings, in the form of a round hollow cylinder, an external electric The electrode of which has the functions of the carrier layer and the cathode, and the inner electrode has the functions of the anode, the intermediate sleeves are made of a heat-resistant or heat-resistant alloy with a KTP identical to the KTE of the SOFC, for example, from the ChS-57 alloy or high-chromium alloys in the form of two hollow cylinders of larger and smaller diameters with the function of the cathodic and anodic current collectors, respectively, with lengths not exceeding the lengths of the SOFC connected by them, with the inner diameter of the larger cylinder allowing the SOFC to be embedded in it, and with the outer diameter of the smaller cylinder a, ensuring its entry into the adjacent SOFC, with windows for supplying the cathode and anode gases, respectively, arranged to overlap the SOFC, articulated by a transition shell of rotation, for example, conical, with the functions of current passage and the part forming the anode space, the end cathode and anode bushings made in the form of a hollow cylinder from the same alloy as the intermediate bushings, with the function of the cathode and anode current collector, respectively, with a length not exceeding the length of the corresponding end T TE assemblies, with an inner diameter that allows the SOFC to be embedded in it, and with an outer diameter that allows it to enter the SOFC, respectively, with windows for supplying the cathode and anode gases, respectively, arranged to overlap the SOFC, coupled to an adapter that allows gas tight and its conductive connection with the parts of the supply or removal of the anode gas and the current supply of the assembly, for example, by welding made of the same alloy as the current collector, in the case used I alloy with good weldability, or with a composite adapter in the case of using an alloy with limited weldability, consisting of two parts interconnected during the manufacture of end sleeves with electrical conductivity and gas tightness, for example, by welding, one of which is articulated with a hollow the cylinder is made of the same alloy, and the second is made of an alloy with good weldability, and the joint of the SOFC with the bushings is made using high-temperature adhesives with KTP identical to the KTE of SOFC and the adhesive temperature It is higher than the maximum operating temperature of the assembly, but lower than the permissible heating temperature of the sleeve material and the temperature of SOFC manufacturing, namely, conductive resistant in the cathode gas, for example, based on composite materials with a phosphate binder, to connect the SOFC cathodes with the cathode current collectors of the bushings to ensure the required electrical conductivity and strength, conductive resistant in the anode gas, for example, based on nickelkermet, for connecting the SOFC anodes to the anode current collectors of the sleeve to ensure the required electrical conductivity and strength, gas-tight insulating resistant in the cathode and anode gases, for example, based on glass-ceramic materials or porcelain, for sealing the ends and the adjacent cylindrical surfaces of SOFC and connecting them to the adjacent surfaces of the bushings to ensure gas tightness and the required strength.  9. The assembly according to claim 8, characterized in that between the ends of the SOFC and the corresponding inner surfaces of the intermediate sleeves connecting the hollow cylinders of the shells of revolution and the adapter of the end cathode sleeve, inner rings of electrically insulating gas-tight material with a CTE identical to the CTE of the material of the bushings are placed, for example, on porcelain base, with an outer diameter that allows them to be embedded in hollow cylinders of cathodic current collectors, with an inner diameter approximately equal to the inner diameter of the hollow cylinders current collectors, with the shape of the end part identical to the corresponding surface of the bushings, and with a flat opposite end, a high-temperature electrically insulating gas-tight adhesive is placed between the SOFC end and the ring and between the ring and the corresponding surface of the sleeve to provide sealing of the SOFC end and gas density and mechanical strength of the joint the end face of the SOFC with the ring and the ring with the sleeve, or additionally in the radial clearance between the outer surfaces of the ring and the SOFC directly adjacent to it ortsu and the inner surface of the hollow cylinder of the cathode current collector, the length of the hollow cylinder anode current collectors are selected from the exception of their ends touching respective inner rings, and the length of the hollow cylinder of the cathode current collectors - with the exception of their ends touch the outer surfaces of adjacent sleeves.  10. The assembly according to any one of paragraphs 8 and 9, characterized in that between the ends of the SOFC and the corresponding outer surfaces of the hollow cylinders of the intermediate sleeves of the shells of revolution and the adapter of the end anode sleeve, outer rings of electrically insulating gas-tight material with a CTE identical to the CTE of the material of the bushings are placed for example, on the basis of porcelain, with an inner diameter that allows them to be installed on the hollow cylinders of the anode current collectors, with an outer diameter approximately equal to the outer diameter of the hollow cylinders cathodic current collectors, with the shape of the end part identical to the corresponding surface of the bushings, and with a flat opposite end, a high-temperature electrically insulating gas-tight adhesive is placed between the end face of the SOFC and the ring and between the ring and the corresponding surface of the sleeve to provide sealing of the end face of the SOFC and gas density and mechanical strength connections of the end face of the SOFC with the ring and the ring with the sleeve, or additionally in the radial clearance between the inner surfaces of the ring and the SOFC, immediately adjacent leading to its end, and the outer surface of the hollow cylinder of the anode current collector, the lengths of the hollow cylinders of the cathode current collectors are selected with the exception of touching their ends of the corresponding outer rings, and the lengths of the hollow cylinders of the anode current collectors are excluding touching their ends or the inner surfaces of adjacent bushes, or corresponding inner rings.  11. The assembly according to claim 10, characterized in that the dimensions and configuration of the outer surface of all outer rings of insulating material or part thereof, for example, mounted on the end anode sleeve and parts evenly spaced along the assembly length of the intermediate sleeves, are made to ensure distance assemblies in more complex structures, for example, in assembly blocks, with the required step, for example, in the form of a spline surface with a diameter along the protrusions of the slots equal to the required step, and with a diameter along the valleys approximately equal to intermeshing diameter hollow cylindrical cathode current collector bushings.  12. The assembly according to any one of claims 8 to 11, characterized in that the anodes of the last or last SOFC along the anode gas in the assembly and the high-temperature electrically conductive adhesive connecting them to the anode current collectors of the respective bushings are made of materials resistant to reduction, and in oxidizing environments, for example, based on a composite material containing oxides of zirconium, cobalt, yttrium and some other metals, or a mixture of cerium oxide with platinum.  13. The assembly according to any one of claims 8 to 12, characterized in that the lengths of the last or last SOFC along the anode gas in the assembly are made larger than the lengths of the remaining SOFC in the assembly. 14. A solid oxide fuel cell (SOFC) with a CTE exceeding the CTE of its electrolyte, containing an electrolyte, for example, zirconia stabilized with yttrium oxide, and anode and cathode electrodes located on its opposite sides, characterized in that it has the shape of a round hollow cylinder the outer electrode of which is made of a material with a CTE exceeding the CTE of its electrolyte and identical, for example, the CTE of the material of the bushings connecting the SOFC in assemblies and made of heat-resistant or heat-resistant alloys, and equipped with the function carrier layer ensuring the integrity of SOFC at temperatures ranging from its manufacturing temperature to the minimum operating temperature, for example, a thickness exceeding the value defined by the formula

where S _n , S _e , S _in - the thickness of the outer electrode, electrolyte and inner electrode, respectively;
t _p , t _m is the temperature of SOFC manufacturing and the minimum temperature of its operation, respectively;
α _n , α _e , α _in - the average CTE of the material of the outer electrode, electrolyte and inner electrode, respectively, in the temperature range from t _m to t _p ;
E _e , E _in - the modulus of elasticity of the material of the electrolyte and the inner electrode, respectively, at a temperature of t _m ;
μ is the Poisson's ratio;
[σ _n ] - permissible tensile stress of the material of the outer electrode at a temperature t _m ,
the electrolyte of which is made thin to ensure gas tightness, for example, a thickness of 15-50 microns, and whose inner electrode is made of a material with a CTE less than the CTE of the material of the outer electrode by an amount that ensures it is pressed against the inner surface of the electrolyte in the specified temperature range, for example, at least 1 , 5%, with a thickness that ensures the stability of the compressed electrolyte and the internal electrode in the specified temperature range, for example, exceeding the value determined by the formula
S _in > m • r • [(α _n -α _in ) • (t _p -t _m )] ^0.666 ,
where m is the coefficient determined empirically;
r is the average radius of SOFC,
but not less than the value determined by the formula
S _in> n • S _e • (α _e -α _n) / (α _N -α _c)
where n is a coefficient determined empirically,
in this case, the production of SOFC, for example, by sintering, was performed at a temperature higher than the temperature of manufacture of the SOFC assembly and the maximum temperature of its operation in the composition of high-temperature electrochemical generators.  15. SOFC according to claim 14, characterized in that the outer supporting electrode is equipped with a cathode function, and the inner electrode is equipped with an anode function.  16. SOFC according to claim 15, characterized in that the internal electrode - anode is made of materials that are resistant both in a reducing and in an oxidizing environment, for example, based on a composite material containing oxides of zirconium, cobalt, yttrium and some other metals, or mixtures of cerium oxide with platinum.

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