RU118706U1 - SUPERFLOW PROTECTOR (OPTIONS) - Google Patents

Abstract

1. Protective device super flywheel containing a cylindrical body made of composite material, which creates a vacuum; super flywheel; shaft; bearings; a protective ring made of durable material and installed inside the body with the ability to rotate relative to it, characterized in that the ability to rotate the protective ring relative to the body is carried out by metal needles and rollers installed on two metal ring-screens that are installed between the protective ring and the body , and at the ends of the body they capture the entire rim of the flywheel; the protective device contains a layer of durable porous metal with pores filled with water, mounted on the protective ring from its inner side, and the porous metal is coated on the side of the flywheel rim with a thin separating metal layer, and on all other sides with a thicker separating metal layer; the protective device contains at least one valve on each flat end of the body, each valve is welded (glued) to the body with a thin sealed seam from the outside of the body; above each valve there are two crossed brackets fixed on the outer side of the body; the protective device contains a motor-generator, divided by a flywheel disk into two mirror-symmetrical parts; both stators of the motor-generator are installed from the inside on the flat ends of the housing on both sides of the flywheel disk and contain a cooling system; Both rotors of the motor-generator are made on permanent magnets, integral with the flywheel hub on both sides of the flywheel disc. ! 2. Protective device super flywheel containing cylindrical

Description

The utility model relates to protective devices (chargers) or to protective covers (in the broad sense of the word) of flywheel energy storage devices and can be used wherever an inertial battery can be used, including in transport and household appliances.

Known anti-emergency system of super-flywheel US 20060117904 A1 (publ. 2006.06.08), which is a special "design philosophy" of the flywheel energy storage, aimed at preventing destruction of the rim of the super-flywheel and other parts of the inertial energy storage. The disadvantage of the system is that there is always a chance that destruction of the flywheel rim will happen. But the complete destruction of the rim and the protective casing as such are not considered by this patent.

Storage devices are known for holding parts of rotating parts torn during tests and trapping fragments (SU 1695025 A2, publ. 11/30/1991; SU 1612169 A1, publ. 12/07/1990; SU 1515005 A1, publ. 10/15/1989; SU 1057743 A1, publ. 11/30/1983; SU 308270 A1, publ. 02/08/1971) designed to test the impellers of turbines and compressors and other rotating parts for the maximum speed. However, these devices are not very suitable as a protective casing for a super flywheel, especially when using it in transport and in everyday life, as bulky and have a large mass. For this reason, and also in connection with the purpose of these devices, they do not need any fire protection systems.

Known safety shell flywheel SU 1567823 A1, publ. 05/30/1990, made in the form of a chord winding, placed on the entire surface of the flywheel. Composite materials having greater strength than the flywheel isotropic material are used as the material for the containment shell. However, in such a design, the strength of the material is greater in the center of the shell (there is more thickness), and not along the edges, where the stresses are observed when the flywheel is destroyed. This safety casing is intended for a monolithic flywheel, which does not require a fire system because of its low specific energy. The use of such a shell for a super-flywheel is possible only when using a durable composite material that can withstand high temperatures.

Known anti-explosive memory of the flywheel SU 1530871 A1, publ. 12/23/1989, containing a housing, flexible elements, "spokes" (cylindrical or conical pipes), a working substance, a casing. In the process of energy absorption of the destroyed flywheel, several mechanisms of energy suppression are involved: elastic and plastic deformation of the body and “spokes”, compression and heating of the working substance. The working substance filling the internal cavity of the memory is, for example, viscous oil, porous rubber, loose powder, etc. The disadvantage of this device is its bulkiness and large mass, which is due to the fact that the working substance in it only heats up, and does not melt and does not evaporate.

Known poppy energy storage RU 97785 U1, publ. 09/20/2010, the casing (protective casing) of which has a brake coating on the inside with a melting, evaporation or decomposition temperature lower than that of the casing, with thermal conductivity commensurate with the thermal conductivity of the casing material. To increase the thermal conductivity of the brake coating, its material is saturated, for example, with copper powder. The housing is designed so that an annular calibrated gap is formed between the brake coating and the flywheel rim. If the deformation of the flywheel exceeds the limit, the flywheel rim and the brake cover come into contact, and a strong braking torque occurs, which is used to disconnect the engine from the flywheel. A design flaw can be considered shock sensitivity, high accuracy and, consequently, the cost of manufacturing the casing. This design of the flywheel drive is designed for a monolithic flywheel and cannot work when using a fiber flywheel [1, p. 195]. In addition, this design eliminates only one of the four possible causes of the destruction of the flywheels - from exceeding the angular velocity [1, p.185]. This design is not intended for the complete utilization of the kinetic energy of the flywheel, but only limits the speed. Fatigue failure can occur with a relatively small deformation [1, p. 195], in this case, disconnecting the engine from the flywheel will be impossible. The clearance can be affected by the temperature of the flywheel (aerodynamic heating at low pressure under the casing) and the casing (ambient temperature). The brake coating used in the analogue, which can evaporate, somewhat resembles the layer of porous metal with pores filled with water proposed in this description of the utility model.

Known protective casing with a protective ring, which can be rotated inside the casing in case of destruction of the flywheel [1, p.194, 192-195]. This protective cover has the following disadvantage. In the event of an accident with a high-energy fiber flywheel, such a cover will become very hot (see below) and may cause a fire. In addition, to ensure the necessary strength, a prototype made of steel must have a sufficiently large mass.

Known protective casing of the flywheel [1, p.194-195], containing a vacuum housing, a protective ring wound from steel tape, bearings with seals. Thanks to two bushings and two mounting brackets in case of destruction of the flywheel, the entire body begins to rotate in the direction of rotation of the flywheel, taking on about 1/3 of its energy. A flywheel with such a housing is designed for installation on a vehicle. This protective cover has the following disadvantages. When using such a casing for a high-energy fiber flywheel (super-flywheel), if such a flywheel is destroyed, the entire installation will become very hot (2/3 of the flywheel’s energy turns into heat when it is destroyed) and can cause a fire, especially when using the flywheel energy storage device (computer UPS) , emergency lighting of an apartment, office, etc.). To ensure the necessary strength, such a flywheel casing should have a sufficiently large mass: the mass of the housing with the suspension is almost two times the mass of the flywheel [1, p. 195]. In addition, in the event of a vehicle accident, such a hull may not be able to rotate due to jamming of the axis of rotation of the hull or strong pressure on the hull of any structural elements of the destroyed vehicle.

The technical result of the utility model is aimed at eliminating the fire hazard of high-energy fiber flywheels and reducing the weight of the protective casing with an unchanged safety margin.

The technical result for the first embodiment is achieved by the fact that the protective device of the super-flywheel comprises a cylindrical body made of a composite material in which a vacuum is created; super flywheel; shaft; bearings; a protective ring made of durable material and mounted inside the housing with the possibility of rotation relative to it, and the ability to rotate the protective ring relative to the housing is carried out by metal needles and rollers mounted on two metal ring screens that are installed between the housing and the protective ring, and the ends of the body capture the entire rim of the flywheel; the protective device comprises a layer of durable porous metal, with pores filled with water, mounted on the protective ring on its inside, and the porous metal is coated on the side of the flywheel rim with a thin separating layer of metal, and on all other sides with a thicker separating metal layer; the protective device contains at least one valve on each flat end of the body, each valve is welded (glued) to the body with a thin sealed seam from the outside of the body; each valve has two crossed brackets mounted on the outside of the body; the protective device comprises a motor generator divided by a flywheel disk into two mirror-symmetric parts; both stators of the motor generator are installed inside on the flat ends of the housing on both sides of the flywheel disk and contain a cooling system; both rotors of the motor generator are made with permanent magnets at the same time with the flywheel hub on both sides of the flywheel disk.

The technical result for the second embodiment is achieved by the fact that the protective device of the super-flywheel comprises a cylindrical body made of a composite material in which a vacuum is created; super flywheel; shaft; bearings; a protective ring made of durable material and mounted on the inner side surface of the housing; the protective device comprises a layer of durable porous metal, with pores filled with water, mounted on the protective ring on its inside and covering the rim of the fiber flywheel, the porous metal being coated on the flywheel side with a thin separating layer of metal, and on all other sides with a thicker separating metal layer ; the protective device contains at least one valve on each flat end of the body, each valve is welded (glued) to the body with a thin sealed seam from the outside of the body; on the outside, a valve is mounted on each valve, attached to the external side of the body, located radially, and having a hole (nozzle) near the edge of the body with an axis directed tangentially to the body, looking in the direction of rotation of the flywheel and with a diameter less than or equal to the diameter of the valve opening; inside the nozzle around the valve there are rods that limit and at the same time guide the movement of the valve, and which are made integral with the nozzle body; the axial movement of the valve is limited by a spring resting against the bottom of the nozzle, uncompressed until the valve is activated; the protective device comprises a motor generator divided by a flywheel disk into two mirror-symmetric parts; both stators of the motor generator are installed inside on the flat ends of the housing on both sides of the flywheel disk and contain a cooling system; both rotors of the motor generator are made with permanent magnets at the same time with the flywheel hub on both sides of the flywheel disk; the entire body of the protective device is mounted in a U-shaped support with the possibility of rotation relative to it. The housing of the protective device according to the second embodiment can be installed in several star-connected U-shaped supports with a common axis, with the possibility of rotation about this common axis, or in a frame with the possibility of rotation relative to it.

Instead of porous metal in both versions, thin-walled metal tubes of small diameter can be used tightly laid to each other (for example, wound around the inner side surface of the protective ring) and coated on the flywheel with a thin separating layer of metal, and on all other sides with a thicker separating layer metal, and water should fill not only the tubes themselves, but also the space between them.

Figure 1 shows the design of the protective device according to the first embodiment, designed, for example, for a gyrocar: 1 - housing; 2 protective ring; 3 - porous metal with pores filled with water (or metal tubes with water); 4 - a thin separating layer of metal; 5 - two crossed staples; 6 - safety valve; 7 - thin weld (glue) seam; 8 - flywheel shaft; 9 - a flywheel disk; 10 - winding of the stator of the engine-generator; 11 - channels of the stator cooling system; 12 - permanent magnets of the rotor of the engine-generator; 13 - fiberglass (or composite material) flywheel rim; 14 - metal rollers; 15 - metal needles (as in a needle roller bearing); 16 - a metal ring screen.

Inside the cylindrical evacuated housing 1 made of composite material, a protective ring 2 is installed, made of durable material with the possibility of rotation relative to the housing 1 due to metal needles 15 and rollers 14 mounted on two metal rings-screens 16 that are installed between the housing 1 and a protective ring 2, and along the flat ends of the body capture the entire rim of the flywheel. A layer of strong porous metal 3 is installed on the protective ring 2 on its inner side, with pores filled with water (porous layer), and the porous metal is coated on the side of the flywheel rim with a thin separating layer of metal 4, and on all other sides with a thicker separating metal layer. Inside the housing 1, the bearings have a flywheel shaft 8, the rim of which is made of fiberglass 13 (or composite material), the flywheel disk 9 is made of durable metal. The motor generator is divided into two identical mirror-symmetric parts. Both stator of the motor generator with windings 10 are installed inside on the flat ends of the housing 1 on both sides of the flywheel disk 9 and contain a cooling system, the channels 11 of which are filled with circulating coolant (or gas). Both rotors of the motor generator are made with permanent magnets 12 at the same time with the flywheel hub on both sides of the flywheel disk 9. The memory contains at least one valve 6 on each flat end of the housing 1. Each valve is welded (glued) to the housing with a thin tight joint 7 from the outside. Above each valve 6, two crossed brackets 5 are mounted, mounted on the housing 1 from its outer side, which hold the valve knocked out by steam.

Figure 2 shows the design of the protective device according to the second embodiment, designed for stationary use up to domestic and office, as well as for use in fire hazardous locations.

1 - housing; 2 - a protective ring; 3 - porous metal with pores filled with water (or metal tubes with water); 4 - a thin separating layer of metal; 6 - safety valve; 7 - thin weld (glue) seam; 8 - flywheel shaft; 9 - a flywheel disk; 10 - winding of the stator of the engine-generator; 11 - channels of the stator cooling system: 12 - permanent magnets of the rotor of the engine-generator; 13 - fiberglass (or composite material) flywheel rim; 17 - hole for the exit of steam (nozzle); 18 - pipe; 19 - rods; 20 - spring; 21 - U-shaped support; 22 - axis.

The design of such a casing differs from the first embodiment by the absence of needles 15, rollers 14 and ring screens 16, because a protective ring 2 and a layer of porous metal 3 with pores filled with water, with a separating layer of metal 4 are fixedly mounted on the inner surface of the housing 1. For maximum fire safety, the porous layer 3 is made covering the flywheel rim. Instead of staples 5, pipes 18 located radially are installed on the outer end surfaces of the housing. Each nozzle has an opening (nozzle) 17 at the edge of the housing with an axis directed tangentially to the housing, looking in the direction of rotation of the flywheel and with a diameter less than or equal to the diameter of the valve 6. There are rods 19 inside the nozzle 18 around the valve 6, which limit and simultaneously guide the valve . The axial movement of the valve is limited by a spring 20 resting against the bottom of the pipe 18, uncompressed in the normal position. The housing 1 is installed in the U-shaped support 21 on the axis 22 with the possibility of rotation relative to it (or in several star-connected U-shaped supports with a common axis, or in the frame).

In both versions, a cylindrical body (may be with rounded edges) is used, as it has greater strength compared to a body that repeats the bends of the flywheel.

The sizes of valves 6, brackets 5 and nozzles 18 (as well as rods 19, springs 20 and holes 17 for steam outlet, respectively) depend on the number of valves and with a large number of valves will be smaller than in Figs. 1 and 2. In this case the distance between the flywheel rim and the stator of the engine-generator can also be made smaller, which will increase the compactness of the unit and reduce aerodynamic drag.

Principle of operation. The main problem in holding fragments of modern flywheels is not the protection of the casing from penetration, but the perception of the angular momentum [1, p. 192]. For example, flywheels made by winding fibers without a binder are destroyed almost axisymmetrically, forming easily delayed fragments, but the extremely angular momentum transmitted by them creates a large torque acting on the protective ring [1, p.193-194].

The principle of operation of the storage device is based on the use of the physical properties of water: very high heat of vaporization (and high heat capacity) at a low boiling point.

In case of destruction of the super-flywheel, its fragments (torn fibers) will pierce a thin separating layer of metal 4, then layer 3 of porous metal with pores filled with water (or a layer of tubes). In this case, fragments of the flywheel will deform the metal of the porous layer and this layer will become very hot. The water in the pores (or in the tubes) boils and begins to evaporate. The steam will expand into a vacuum inside the enclosure. The vacuum will disappear, the space under the housing will be filled with steam. When the vapor pressure inside the housing exceeds a predetermined value, the safety valves 6 on the housing will operate. Safety valves can withstand external atmospheric pressure for as long as possible, as well as shock, vibration, etc. due to the fact that they are welded (glued) to the body with a thin seam 7, but when a certain internal pressure is reached, they work, i.e. they are beaten off by steam and held up by crossed brackets 5 (in the first embodiment) or by a spring 20 and a pipe 18, as well as rods 19 (in the second embodiment). In accordance with the formulas for the circumference and area of the circle, the larger the radius of the valve, the easier it is to break the seam 7 with internal pressure (the force per unit length of the seam is proportional to the radius of the valve). Steam will begin to escape into the atmosphere, pressure under the body will drop, the boiling point of water will decrease. Steam will take away all the flywheel energy with it for some time. As shown below, the amount of water required for this is a small part (approximately 1/10) of the mass of the fiberglass flywheel with a tensile strength σ _vp = 4600 MPa with a safety factor of k = nv = 3. Since the pressure under the housing is limited by safety valves, and after them. the response becomes approximately equal to atmospheric, then the boiling point of the water in the pores will be determined first by the response pressure of the valves, and then by atmospheric pressure. The temperature of the protective ring and the body of the charger during the destruction of the flywheel is limited by the boiling point of water (if there is a sufficient amount of it). the flywheel is limited by the boiling point of the water (with a sufficient amount of it). This ensures the fire safety of high-energy fiber flywheels when using the proposed design of the memory.

There are at least two safety valves: at least one on each flat end of the casing, therefore, at any position of the casing with the flywheel after an accident, steam can go outside. The valve capacity is calculated based on the fact that the pressure after the valves are activated is only slightly higher than atmospheric, and, thus, the boiling point of water does not greatly exceed 100 ° C.

Introducing a porous metal with pores filled with water, we noticeably increase the mass of the protective casing, but: 1) the porous metal itself has some strength and, plus, the impact energy is spent not only on the deformation of the porous metal, but also on the evaporation of water, so the load on the protective the ring during the destruction of the flywheel will be less, because larger fragments first pass through the porous layer, while small fragments do not reach the protective ring at all; 2) the temperature of the protective ring cannot greatly exceed the boiling point of water even at the border with the porous layer (if, as in the proposed versions of the storage medium, the porous layer is fixed on the protective ring and cannot be rotated relative to it), which increases the strength of the protective ring compared to the case without using porous layer. For these two reasons, the weight of the protective ring can be reduced. But if during an accident the temperature of the protective ring and the housing of the charger is not very high, then they can be made not of steel, but of lightweight composite material, and the composite material of the case can have poor thermal conductivity (for example, fiberglass). This is achieved by reducing the mass of the super flywheel memory.

If the composite used to make the charger case has poor thermal conductivity, then when calculating the required mass of water in a porous metal (see formula (6) below), the heat capacity of the charger case does not need to be taken into account (but it is also very low in metals compared to the heat of vaporization of water) .

The torque during the destruction of the flywheel will remain the same, the evaporation of water will not affect it. in any case, an absolutely inelastic impact occurs with the transmission of the corresponding impulse (angular momentum).

In the first embodiment, the torque is greatly weakened due to the fact that the protective ring 2 together with the porous layer 3 can rotate relative to the casing body. This is ensured by the fact that metal needles 15 and rollers 14 are located between the housing and the protective ring. Thus, the entire casing can be thought of as a large angular contact needle and roller bearing without a cage. This bearing will work in the unlikely event of a flywheel failure, i.e. just once. After the flywheel is destroyed, its fragments will give an impulse to the porous layer and the protective ring, as a result of which the protective ring and the porous layer fixed on it will come into rapid rotation, which after some time will stop under the action of the friction moment between the needles and rolling surfaces, as well as between the needles themselves, if they are placed close together as in a bearing (the same goes for rollers). This moment of friction will be limited by the torque acting on the housing.

In the second embodiment, when the super flywheel is destroyed, the torque does not rotate the protective ring with the porous layer, but the entire flywheel assembly together with the electric machine, which is mounted in the U-shaped support 21 on the axis 22 with the possibility of rotation relative to it (or several connected by a star U-shaped supports with a common axis, or in a frame). The rotation of the housing will stop after some time due to the reactive forces acting on the housing from the side of the steam flowing out of the holes (nozzles) 17 in the nozzles 18 and friction in the suspension.

The torque on the case will appear immediately at the moment of the impact of the fragments on the porous layer 3 and the protective ring 2 (inelastic impact), and the reactive moment will appear with a noticeable delay, because for its appearance, several processes must occur: heating and evaporation of water in the pores, vapor filling of the internal space under the casing, pressure increase in this internal space until the valves operate, and after their operation, filling the pipe with steam and increasing the pressure in it. And only at the last stage will the steam flow out of the holes (nozzles) of the nozzles and the reactive moment will appear. By this time, the flywheel housing will already rotate and the task of the jet nozzles is to stop or at least reduce the rotation frequency of the housing. In addition, when the protective ring with a porous layer (according to the first embodiment) or the entire charger body (according to the second embodiment) is untwisted under the influence of the collapsed flywheel's torque, evaporation, and in the second embodiment and the steam moves to the valves, centrifugal force will prevent .

The greater the specific energy of the flywheel, the greater the torque and the more mass is required to counter it. Therefore, rotation of the entire flywheel housing is more promising, moreover, together with the engine-generator (i.e., the second embodiment), and not only the protective ring and the porous layer (i.e., the first embodiment). But, true, in the first embodiment, with the increase in specific energy, the necessary mass of water and, accordingly, the porous layer also grows. In addition, the second embodiment has a somewhat more bulky design than the first embodiment. In any position after an accident, shock, etc. in the first embodiment, nothing will interfere with the rotation of the protective ring and the porous layer, because the case is durable and cannot be jammed as in the prototype or as in the second embodiment.

When water evaporates, the moment of inertia of the porous layer decreases slightly, which will lead to a slight increase in the angular velocity for both versions.

The thermal conductivity of the porous layer must be good for the possibility of rapid evaporation of water and, thus, rapid quenching of the kinetic energy of flywheel fragments. In addition, it is desirable that the porous layer be strong - while further increasing the strength of the entire memory. It is better to use porous stainless steel - foam metal (or some other sufficiently strong porous metal, for example, titanium). The specific heat of vaporization of iron is even greater than that of water, but the boiling point of iron in an accident can hardly be achieved (and it cannot be achieved from the point of view of fire safety).

The cylindrical body is more durable and lighter than the body, which repeats the shape of a super-flywheel. The presence of vacuum inside and atmospheric pressure outside gives some casing durability during axisymmetric destruction of the flywheel.

Maximum specific kinetic energy. The kinetic energy of the flywheel in the form of a thin ring or thin-walled cylinder is found by the formula

Where

I is the moment of inertia of the flywheel (ring);

ω is the angular velocity;

m is the mass of the flywheel;

R is the radius of the flywheel (ring)

n is the rotation frequency.

Flywheel specific kinetic energy, i.e. stored energy (1), referred to 1 kg of flywheel weight

On the other hand peripheral speed (at the rim).

Then the specific kinetic energy of the flywheel . Fiber flywheels have a higher specific energy, which means more peripheral speed.

Two different methods: the conclusion from the equilibrium condition of the element of the ring or the thin-walled cylinder in the rotating non-inertial reference frame (see [3, p. 420]), as well as the conclusion of the equilibrium of the half-ring (ie, half of the entire flywheel) give the following formula for maximum (limiting) frequency of rotation of a ring or thin-walled cylinder:

Where

R is the radius of the ring;

σ _T is the yield strength (or, instead of σ _T, one can take σ _v.d. - ultimate strength);

k is the safety margin specified by the designer (k = n _T or k = n _B depending on what is taken: σ _T or σ _r.s. );

ρ is the density of the ring material.

If we substitute (3) in (2), then the maximum specific kinetic energy of the flywheel in the form of a ring is

It follows that materials with a maximum a are best suited for a flywheel. at a minimum density ρ.

In formula (4), depending on the shape of the flywheel, there can be a different numerical coefficient (shape coefficient) [1, p.16].

Calculation of the parameters of the super flywheel. If we use real strong fiberglass cσ _{in, p} = 4600 MPa and density p = 2500 kg / m ³ for winding the flywheel, then we obtain the specific kinetic energy E _beats = 307 kJ / kg with a safety factor of k = 3. For industrial carbon fiber (high strength) with σ _{in, p} = 3300 MPa and a density of 1760 kg / m ³ , almost the same specific energy is obtained: 312.5 kJ / kg. But carbon fiber has flammability, which is undesirable for an inertial battery, because in the event of an accident, the temperature of the unit can rise to very high values due to the fact that in addition to the heat generated when the flywheel fragments hit the casing, these fragments can burn if the casing is not tight.

Due to the potential energy of elastic deformation, the total specific energy reserve of the flywheel is slightly increased. In most cases (for materials actually existing at the moment), the stock of potential energy of elastic deformation does not exceed 0.5% of the stock of kinetic energy. Therefore, when constructing an inertial accumulator in most cases, the potential energy of elastic deformation can be neglected. However, for glass fiber (σ _{in, p} = 4600 MPa, elastic modulus E = 85 GPa), the ratio of the maximum potential and kinetic energies is Epmax / Ekmax = 0.0180, i.e. 1.8%, which is associated with a relatively small modulus of elasticity. In accurate calculation, this energy must be taken into account.

The temperature of the flywheel with a simple casing after the destruction of the flywheel. Equating the kinetic energy of the flywheel (1) and the amount of heat required to heat a given mass of substance by ΔТ, we estimate the temperature change of the entire flywheel unit in the event of an accident (we assume that the entire unit is made of one material, for example, steel and heat is not given to the environment) :

Where

m is the mass of the flywheel;

C is the specific heat of the material;

M = m + m _mg + m _leather - the mass of the entire unit, made up, respectively, of the mass of the flywheel, the mass of the motor generator and the mass of the casing (without a porous layer and a protective ring).

If the protective casing is made without a porous layer with pores filled with water, then locally on the inner surface of such a casing in case of an accident the temperature will be high, much higher than by formula (5), because the rate of heat transfer through thermal conductivity is not infinite, especially if the casing is made of composites with poor thermal conductivity. Formula (5) gives the value of the temperature change after all the heat is evenly distributed throughout the unit without heat exchange with the environment.

If the thermal conductivity of the material of the flywheel itself (fiberglass) is much lower than the heat conductivity of the housing (steel), then to estimate the heating value of the installation, we can neglect the mass of the flywheel and take into account only the mass of the housing and motor generator (if the destruction of the flywheel is not complete, or if the pieces into which the flywheel fell not very small). A considerable part of the mass of the motor-generator falls on the copper winding, but the specific heat of copper (390 J / kg-deg) is close to the specific heat of steel (469 J / kg-grad), therefore, in the estimated calculation, we can assume that the motor-generator and the casing are steel .

For a fiberglass flywheel weighing 1 kg and a radius of 0.1 m in the event of an accident at maximum speed (3), if we assume that only the steel casing (normal) and the motor generator will heat up, and the glass does not conduct heat well ¹ ( ¹ Thermal conductivity coefficient steel is approximately 42 times greater than the thermal conductivity of the glass), then the casing and motor generator with a total mass of 2 kg will heat up to 350 ° C (from room temperature 23 ° C, and the temperature change according to (5) will be ΔТ = 327 ° C). Such a temperature can cause a fire, especially since the local temperature on the inner side surface of the casing will be much higher and the heat will not immediately pass from this part of the casing to the motor generator. For a flywheel, industrial carbon fiber (high strength) produces a temperature change of ΔT = 333 ° C.

Estimation of the mass of water. So, a fiberglass ring with a safety factor of k = 3 can accumulate up to 307 kJ / kg. This energy with a ring mass of 1 kg is enough to heat 2 kg of steel at 327 ° C, which is fire hazard when using an inertial battery for household or office use (327 ° C is the melting point of lead). Therefore, as already mentioned, it is proposed to surround the flywheel with a cylindrical layer of water enclosed in the pores of a porous metal, the specific heat of which is ² ( ² Moreover, its change when heated to 100 C is small - see the graph in [2, p. 75, Fig. 21] and with increasing pressure it is also small [4, p.213]) c = 4.19 kJ / (kg-K), (9 times less in steel: 0.47 kJ / (kg-K)), and specific heat the vaporization of water at a boiling point is three orders of magnitude (!) greater: r = 2.26 MJ / kg. For other liquids, the specific heat of vaporization is 3-10 times less. For solids, the specific heat of vaporization can be several times greater than for water (for example, for aluminum, r = 10.9 MJ / kg (according to other sources, 12 MJ / kg), for lead r = 8.6 MJ / kg, for iron r = 6.34 MJ / kg, for magnesium g = 6.0 MJ / kg), but the high boiling point of solids alone guarantees a fire (boiling point of the above substances, respectively 2500 ° C, 1750 ° C, 2735 ° C , 1095 ° C).

The kinetic energy Еk of the flywheel will be used for heating water, for vaporization, as well as for heating the mass of metal in the porous layer and the protective ring (we do not take into account the heating of the composite housing of the charger). Then, considering that the porous layer and the protective ring are made of one metal, we obtain:

E _k = c _ρ mΔT _in + rm + s (m _nc + m _Зk ) ΔT _in

Where

with _p - specific heat of water at constant pressure; m is the mass of water;

ΔT _in - change in its temperature from initial to boiling point;

r is the specific heat of vaporization;

C is the specific heat of the metal of the porous layer and the protective ring;

m _nc is the mass of the metal of the porous layer;

m _zk - the mass of the protective ring.

In order to turn all kinetic energy of such a flywheel into steam in the event of an accident, a mass of water is required

Even without taking into account the heating of the metal of the porous layer and the protective ring according to (6), it turns out from = 0.307-10 ⁶ / (4.19-10 ³ -80 + 2.26-10 ⁶ ) = 0.118 kg of water and this with the mass of the flywheel 1 kg That is, water vapor is a good thermal battery. When using a steel porous layer and a steel protective ring, the second term in the numerator (6) does not exceed 2% of g.

The higher the air temperature, the less ΔТ _in (up to 100 ° С), and a slightly larger required mass of water in the pores (the term with _ρ ΔТ _in is about 15% of g).

Estimation of the size of the porous layer. Let the rough mass of water be 1/10 the mass of the rim of a flywheel made of fiberglass without a binder. If their densities were equal and equal to the density of water, then water would need to take 1/10 of the volume of glass (figa). Since the density of the glass is 2.5 times greater than the density of water, then the mass of the same volume is the same times as much and water will be required 2.5 times more in volume (Fig. 36). If the water volume is half the volume of the porous layer (but may be less), then the volume of the porous layer with water equal to 1/2 the volume of the glass will be required (Fig.3c). And finally, it must be taken into account that fiberglass occupies a larger volume than glass with the same mass, which depends on the diameter of the fibers. If the volume of fiberglass is 2 times larger than the volume of glass of the same mass, then the volume of the porous layer will be equal to 1/4 of the volume of fiberglass (Fig. 3d), i.e. the porous layer is quite thin. Select the sector in which the fiberglass and the porous layer are located. Since the porous layer is located farther from the center, on a section by a plane passing through the axis of rotation of the flywheel, the cross-sectional area of the porous layer will be less than 1/4 of the cross-sectional area of the glass fiber due to the longer arc circle. But the thickness of the porous layer is still desirable to take a little more, because in addition to fiberglass, the metal rim to which the fiberglass and the flywheel metal disk is attached can be destroyed (they have less speed, but the pieces can be larger). However, behind the porous layer there is a protective ring, due to which the thickness of the porous layer can, in principle, be taken less. In case of destruction of the hub with permanent magnets, their fragments will be a small vacuum in the casing. Therefore, the valves will work and steam will escape through them for some time, taking away and dissipating the energy of the flywheel in the atmosphere, and in the second embodiment, also creating a reactive moment to stop the flywheel assembly, spun momentum transmitted by the fragments.

Benefits. The proposed memory allows you to more widely use the advantages of an inertial battery.

The main advantages of an inertial battery compared to an electrochemical one are: 1) long service life; 2) the capacity does not depend on time, i.e. from the number of charge-discharge cycles; 3) the ability to quickly charge and discharge, i.e. high power charging (which is convenient for vehicles) and discharge; 4) a sufficiently large capacity; 5) high efficiency (with a sufficiently large power of the used electric machine); 6) absolute environmental cleanliness (no chemical fumes).

The use of a porous layer with pores filled with water in the protective casing can open the way for wider use of the inertial accumulator in both moving and stationary objects, including fire hazard ones, up to application in everyday life and in the office (computer UPS, emergency lighting of an apartment, office etc.)..

The use of an electric machine divided into two mirror-symmetric parts allows achieving the same compactness as when using an end electric machine [5], [6] but without the disadvantages of end electric machines described in [7, pp. 25-26]. In addition, when using such an electric machine, the same protection against destruction of the flywheel hub as described in US 20060117904 A1 (publ. 2006.06.08), provided there by a special screen, is provided.

Literature

1. Genta J. The accumulation of kinetic energy. Theory and practice of modern flywheel systems: Per. from English - M .: Mir, 1988 .-- 430 s, ill.

2. Koshkin N.I., Shirkevich M.G. Handbook of elementary physics. - M., Science, 1974.

3. Lyuboshits M.I., Itskovich G.M. Handbook of resistance to materials. Minsk, “Highest. school ", 1969. Chapter 14. Problems of dynamics in the resistance of materials. §14.1. Determination of stresses at given accelerations (p. 420).

4. Physical quantities: Reference book / A.P. Babichev, N. A. Babushkina, A. M. Gratkovsky and others. Ed. I.S. Grigorieva, E.Z. Meilikhova. - M .: Energoatomizdat, 1991 .-- 1232 p.

5. Kirko I.M., Kirko G.E. Flywheel as an energy storage and converter, http://www.skif.biz/index,php?name=Pages&op=page&pid ^{r =} 128. - [1998].

6. RU 2417504 CI, published on 04/27/2011.

7. Ledovsky A.N. Electric machines with highly coercive permanent magnets. - M .: Energoatomizdat, 1985 .-- 168 p.

8. Handbook of physical quantities. / A.V. Bologoe, I.V. Kozhukhov and others. Ed. prof. G.A. Ryabinin .-- St. Petersburg, Lenizdat; Soyuz Publishing House, 2001. - 160 p.

Claims (4)

1. A protective device of a super-flywheel, comprising a cylindrical body made of a composite material in which a vacuum is created; super flywheel; shaft; bearings; a protective ring made of durable material and mounted inside the housing with the possibility of rotation relative to it, characterized in that the ability to rotate the protective ring relative to the housing is carried out by metal needles and rollers mounted on two metal ring screens that are installed between the protective ring and the housing , and at the ends of the body they capture the entire rim of the flywheel; the protective device comprises a layer of durable porous metal with pores filled with water mounted on the protective ring on its inner side, and the porous metal is coated on the side of the flywheel rim with a thin separating layer of metal, and on all other sides with a thicker separating metal layer; the protective device contains at least one valve on each flat end of the body, each valve is welded (glued) to the body with a thin sealed seam from the outside of the body; each valve has two crossed brackets mounted on the outside of the body; the protective device comprises a motor generator divided by a flywheel disk into two mirror-symmetric parts; both stators of the motor generator are installed inside on the flat ends of the housing on both sides of the flywheel disk and contain a cooling system; both rotors of the motor generator are made with permanent magnets at the same time with the flywheel hub on both sides of the flywheel disk. 2. A protective device of a super-flywheel comprising a cylindrical body made of a composite material in which a vacuum is created; super flywheel; shaft; bearings; a protective ring made of durable material and mounted on the inner side surface of the housing, characterized in that the protective device comprises a layer of durable porous metal with pores filled with water, mounted on the protective ring on its inside and covering the rim of the fiber flywheel, and the porous metal is coated on the flywheel side with a thin separating layer of metal, and on all other sides with a thicker separating layer of metal; the protective device contains at least one valve on each flat end of the body, each valve is welded (glued) to the body with a thin sealed seam from the outside of the body; on the outside, a valve is mounted on each valve, attached to the outer side of the body, located radially and having an opening (nozzle) near the edge of the body with an axis directed tangentially to the body, looking in the direction of rotation of the flywheel, and a diameter less than or equal to the diameter of the valve opening; inside the nozzle around the valve there are rods that limit and at the same time guide the movement of the valve, and which are made integral with the nozzle body; the axial movement of the valve is limited by a spring resting against the bottom of the nozzle, uncompressed until the valve is activated; the protective device comprises a motor generator divided by a flywheel disk into two mirror-symmetric parts; both stators of the motor generator are installed inside on the flat ends of the housing on both sides of the flywheel disk and contain a cooling system; both rotors of the motor generator are made with permanent magnets at the same time with the flywheel hub on both sides of the flywheel disk; the entire body of the protective device is mounted in a U-shaped support on the axis with the possibility of rotation relative to it. 3. The protective device of the super-flywheel according to claim 2, characterized in that the entire body of the protective device is mounted in several star-connected U-shaped supports with a common axis with the possibility of rotation relative to it. 4. The protective device of the super-flywheel according to claim 2, characterized in that the entire housing of the protective device is mounted in the frame on the axis with the possibility of rotation relative to it.