FIELD: power engineering; buffer energy accumulators; transport systems, emergency power supply units, wind-power and solar stations.
SUBSTANCE: proposed accumulator has flywheel and drive with supports located in evacuated chambers having different levels of vacuum and separated from each other; evacuated chambers are filled with rarefied gas; electric drive is located in one of them at low level of vacuum; flywheel is located in other chamber at increased level of vacuum of 0.1 to 0.01 Pa; turbo-molecular pump mounted on flywheel shaft is used for maintenance of increased vacuum in chamber by pumping the gas from this chamber to chamber of drive. At least one chamber is used for drives and supports which is separated from flywheel chamber by seals; they are hermetic during working rotational speeds of flywheel.
EFFECT: low aerodynamic losses in flywheel chamber; enhanced cooling efficiency without availability separate cooling systems.
7 cl, 3 dwg
The technical field
The invention relates to the field of energy and can be used as a buffer store of energy, for example, to electrified transport systems, sources of emergency power, uninterruptible power for wind and solar power plants.
The level of technology
Known flywheel energy storage with the flywheel and the drive with their legs placed in two separated vacuum chambers filled with rarefied gas with different levels of vacuum in them, and in one of them, with a low level of vacuum, placed the drive, and the other, with a high level of vacuum of 0.1... 0.01 PA, put the flywheel is placed on its shaft turbo-molecular pump, a support in the chamber of the flywheel is increased vacuum level by constant pumping gas from the chamber into the chamber of the actuator (see J. Gent. “The accumulation of kinetic energy”, Moscow, Mir, 1998, pp.178-180, ris.3.10). This unit is adopted for the prototype.
The drawback of the prototype is mainly what turbomolecular pumps of all types have a maximum outlet pressure of less than 1... 10 PA - pressure relating to the boundary between the middle and high vacuum (Rozanov LN. Vacuum technology, Moscow, Vysshaya SHKOLA, 1987, p.93 and 196, PL. P4). This means that camera, where is the drive must support this very low pressure at which the gas has a relatively low thermal conductivity, and therefore do not provide efficient cooling of electric machines. At a higher pressure relating to another level of vacuum is low or forvacuum, in which the cooling conditions are favorable, you cannot work turbomolecular pump. Therefore, the prototype provides a separate cooling system electrical machinery, significantly complicating the device. Another disadvantage of the prototype is that at low frequencies of rotation that can occur in practice, turbomolecular pump inoperable.
Task to be solved by the present invention is directed, is the creation of a flywheel drive for low aerodynamic losses in the chamber of the flywheel at the same time with effective cooling of the actuator without the use of special cooling systems. The technical result is to provide a high vacuum in the chamber of the flywheel at low vacuum in the chambers of the actuator, including when slowly rotating or stationary flywheel, thereby achieving high heat transfer from the heating elements of the actuator, for example of the rotor of the electrical machinery to the chamber walls. In fizi is e vacuum under low, middle and high vacuums means the state of gas, in which respectively the criterion Knudsen much less than one, is close to unity and a lot more units. Approximately for technical calculations Knudsen criterion can be defined as L/deff, where L is the length of the free path of the gas molecules; deffeffective size of the vacuum chamber. For camera rotation of the flywheel with a typical gap δ between the flywheel and the chamber walls, for example about 0.01 m, deff≈2δ i.e. 0,02 m the length of the free path of the molecules depending on the gas pressure P (PA) is defined as L≈ 0,0063/P, m was to be the pressure relating to secondary vacuum chambers of rotation normal size is R≈ 0,0063/0,02=0,315 PA.
Pressure substantially in excess of this value is to low vacuum, and if significantly below it to high (see the above book Rozanov, L.N., p.20-23). It should be noted that the same value of the Knudsen criterion corresponds to a different gas pressure, depending on the size and configuration of the vacuum chamber. For example, a pressure of 0.1 PA is a high vacuum chamber flywheel diameter and a height of 1 meter and a gap between the flywheel and the walls of 0.01 m, the pressure 0,315 PA is, as noted above, the average vacuum for the same camera. But if this camera max the Vic to withdraw, it increased the volume of the pressure corresponding to the average vacuum (if the camera is made in the form of a cylinder with a diameter of 1 m), is approximately equal 0,0063 PA, and the pressure of 0.1 PA, and the pressure 0,315 PA, will have low vacuum. Such physical properties of the vacuum, as the aerodynamic resistance and thermal conductivity, dependant on criteria Knudsen, and not on the absolute values of the gas pressure.
To solve the problem and achieve a technical result in the known flywheel drive containing the flywheel and drive with the legs placed in a separated vacuum chambers filled with rarefied gas with different levels of vacuum in them, and in the chamber with a low level vacuum encapsulated actuator supports, but the camera - with a high level of vacuum is placed flywheel, drive camera with supports are separated from camera flywheel, at least one seal is airtight, at least in the mode of operating frequencies of rotation of the flywheel and the pressure of the gas in the chambers of the actuators and supports above maximum pressure release turbomolecular pumps and refers to the low vacuum with the criterion Knudsen below 0.01, and the camera flywheel - refers to the vacuum with the criterion Knudsen exceeding 0.01.
There may be other embodiments of the invention, according to which neo is absolutely essential, to:
the seal between the chambers would be performed hydrodynamic;
the seal between the chambers would be made static type;
the seal between the chambers would be performed combined static-dynamic type;
he would be provided with an additional camera and the drive supports arranged in the additional chamber that is separated from the camera of the flywheel, at least one seal is airtight, at least in the mode of operating frequencies of rotation of the flywheel;
camera would be equipped with valves for camera message flywheel with cameras drives and supports by reducing the rotational speed of the flywheel below working;
the vacuum level in the chamber of the flywheel would meet the criterion Knudsen, not less than two orders of magnitude greater than the same in the chambers of the actuators and bearings.
Brief description of drawings
1 shows a General diagram of the flywheel of the drive.
Figure 2 - diagram of the lower seal (broken).
Figure 3 - top seal (broken).
Flywheel drive contains the flywheel 1, the shaft 2 of which is kinematically connected to the actuators, in this case with two - rotor 3 electrical machinery placed in the chamber 4 separated from the chamber 5 of the flywheel 1 seal 6, and with a mechanical drive, such as wave, allowing the output rotation of the tight Polo is TEI, moreover, the wave generator 7 is placed in the chamber 8 is separated from the chamber 5 by the seal 9. Flexible wheel 10 wave transmission seals the chamber 8 from the atmosphere, and a hard wheel 11 with the output shaft 12 is at atmospheric conditions. The supports 13 and 14 are in the chambers of the actuator. Seal 6 and 9, for example, the combined type - centrifugal-static (2 - seal 6 and figure 3 - seal 9). They contain a rotating cavity 15 that is connected with the shaft 2, and the stationary cavity 16 that is connected to the housing of the camera. Annular gap between the cavities filled with lubricant 17 used in vacuum systems. On the left in figure 2, figure 3 shows the lubricant level h in the dynamics, and on the right with a stationary flywheel 1, when the pressure difference in the chambers 4, 5 and 8 balanced by the column of the liquid height difference H 100... 120 mm When h&λτ; H as in the dynamics of oil Argonauts out due to its rotation. However, it is possible to use a purely dynamic, and purely static (e.g., magnetic) seal.
In the chamber 5 is equipped with a pressure corresponding to medium and high vacuum is for the usual dimensions of the camera 5 and the gap between the flywheel and the chamber walls about 0.1... 0.01 PA or Knudsen criterion of 0.6... 6, and in the chambers 4 and 8 corresponding to the low vacuum level and substantially greater than the maximum discharge pressure of the turbomolecular pump is in - 10 PA and up to 100 PA and above when criteria Knudsen below 0.01 for any real size flywheel drive. Desirable rarefied gas chambers helium.
An example implementation of the invention
In the chambers 4, 5 and 8 using the appropriate vacuum pump is set to the appropriate pressure gas, preferably helium. Helium provides, on the one hand, reduced power loss on the rotation of the flywheel, and on the other hand, the high heat transfer in the drives. It is known that gases at low vacuum level have almost the same thermal conductivity, and at atmospheric pressure (see Rozanov LN. Vacuum equipment, Meters, High school, 1987, p.25, Fig.2.2). Therefore, when the pressure of 100 PA and higher cooling drives a rotor 3, and the wave generator 7 will be satisfactory. And conditions of lubrication will meet the necessary requirements, because the pressure of 100 PA and higher will not cause the active gas and evaporation of the lubricant. However, the main effect of the device is that the force action of the pressure differential between the chambers 5 and 4, 8 will be negligible - the difference between, for example, of 0.1 PA in the chamber 5 and 100 PA in the chambers 4 and 8 is the impact of only 0.01 N on 1 cm2the active surface of the seal 6 and 9. If I had to condense the normal atmospheric pressure in the chambers 4 and 8, the force on these plot the value would be 1000 times higher. Thus, almost without violating the cooling mode actuators and increasing requirements for its oxidation, corrosion resistance and dust, the device allows the use of the simplest designs of seals 6 and 9, two to three orders of magnitude less intense than at atmospheric pressure in the chambers 4 and 8. And this at a much lower complexity, size, weight, cost, power losses during rotation and significantly more durable. In particular, represented in figure 2 and 3 combined seal is healthy and can withstand a pressure differential of 100 PA in the dynamics and stationary flywheel 1.
If only dynamic seal, such as centrifugal or vintageromania, the size of the marked pressure drop can be significantly less, 30... 50 mm along the axis. In this case, the valves 18 and 19 connecting the camera 4 and 8 with the chamber 5, to operate at the reduced rotational speed of the flywheel 1 below working.
In the case of static, such as magneto-fluidic seals, their size, complexity, cost and loss in rotation is much smaller than when the differential pressure of one bar (100 kPa).
The invention meets the criterion of “industrial applicability”because feasible using known materials, means of production and technologies.
And the use of the present invention allows to create flywheel drive with high efficiency, when it is sufficient simplicity, and drives the selection and supply of power from the flywheel and the flywheel may be several, to ensure sufficient cooling.
1. Flywheel drive containing the flywheel and drive with the legs placed in a separated vacuum chambers filled with rarefied gas with different levels of vacuum in them, and in the chamber with a low level vacuum encapsulated actuator supports, and in the chamber with a high vacuum level is placed flywheel, characterized in that the actuator with the supports are separated from camera flywheel, at least one seal is airtight, at least in the mode of operating frequencies of rotation of the flywheel and the pressure of the gas in the chambers of the actuators and supports above the maximum pressure release turbomolecular pumps and refers low vacuum with the criterion Knudsen below 0.01, and the pressure in the chamber flywheel relates to vacuum with the criterion Knudsen exceeding 0.01.
2. Flywheel drive according to claim 1, characterized in that the seal between the chambers are made of hydrodynamic.
3. Flywheel drive according to claim 1, characterized in that the seal between the chambers are made of a static type.
4. Flywheel drive according to claim 1, characterized in that the seal between the compartments have combined statically di is omicheskogo type.
5. Flywheel drive according to claim 1, characterized in that it is provided with an additional camera and the drive supports arranged in the additional chamber that is separated from the camera of the flywheel, at least one seal is airtight, at least in the mode of operating frequencies of rotation.
6. Flywheel drive according to any one of claims 1, 2 or 5, characterized in that the chamber is provided with valves for camera message flywheel with cameras drives and supports by reducing the rotational speed of the flywheel working below.
7. Flywheel drive according to any one of claims 1 to 6, characterized in that the vacuum level in the chamber of the flywheel meets the criterion Knudsen, not less than two orders of magnitude greater than the same in the chambers of the actuators and bearings.