Compressed air energy storage system based on open accumulator concept
Comparison of unit volume energy density between closed accumulator and open accumulator Table 1 compares the characteristic parameters of four typical energy storage devices. It can be seen from Table 1 that the efficiency of the open accumulator is higher than that of the lead-acid battery, and the weight energy density and the volumetric energy density are equivalent to those of the lead-acid battery. The unit power device cost is similar to that of the super capacitor and the high-speed flywheel, but the unit energy device costs far. It is lower than other three energy storage devices, especially suitable for energy storage of large-capacity electric energy. It can be seen that open-type accumulator energy storage is a very competitive energy storage technology. Once this technology is promoted and applied, it will definitely create an emerging huge market for the hydraulic industry.
Table 1 Comparison of characteristic parameters of four typical energy storage devices Lead-acid super high-speed open battery capacitor flywheel energy efficiency Weight energy dense volume energy density unit power device cost / kW unit energy device cost can be as high as 175kJ / L, weight energy density can be Up to 220kJ/kg, almost 40 times that of a closed accumulator. At the same time, it can be seen that the energy density of the open-type accumulator with isothermal expansion is significantly higher than that of the open-type accumulator with adiabatic expansion, which is about 2.53 times.
1 Closed accumulator and open accumulator The accumulator commonly used in hydraulic systems is a closed accumulator whose compressed air chamber is closed and the volume of the chamber changes with the pressure.
In the accumulator, the air in the accumulator is compressed by the volume to R, and the pressure is increased from A (usually 1 atmosphere) to the compression energy of the compressed air in the accumulator is the AFEBGA area, and the oil is drained in the common closed accumulator. The pressure at the time of termination, that is, the compression energy released by the compressed air in the accumulator is only the FEBG area, and the energy of the AFG area is not utilized. For this purpose, the actual volume of the closed accumulator includes not only the volume of the oil (F3-72) but also the volume of the remaining compressed air. R. Recently introduced by the closed accumulator and the compressed air energy in the open accumulator. The so-called open accumulator means that the pressure at the end of the accumulator drain is approximately that the compression energy (AFEBGA area) of the compressed air in the accumulator is almost fully utilized, and the volume of the open accumulator is only The oil volume (F, -F2), so the energy storage capacity per unit volume of the open accumulator is much higher than that of the closed accumulator. The energy storage density per unit weight of the open accumulator is also much higher than that of the closed accumulator. Device.
For the energy density per unit volume of closed accumulators and open accumulators, the currently used closed accumulators have a volumetric energy density of only 4.5 kJ/L and a weight density of only 6.5 kJ/kg. Open energy storage The volumetric energy density of the device is much larger than that of a closed accumulator. The accumulator pressure is calculated as 35 MPa, and the isothermal expansion of the open accumulator volume energy density transmission and control direction teaching and research work.
: * Body Robbery; Controlled Hydraulic Pneumatic Patent Forum (17) Compressed Air Energy Storage System Based on Open Accumulator Concept Zhang Guoxian (Shanghai University, Shanghai 200444) Zhang Guoxian: Compressed Air Energy Storage System Based on Open Accumulator Concept Page 59 2 A compressed air storage system based on an open accumulator is patented for an open air accumulator based compressed air energy storage system in 2011.
The system has a low pressure gas-liquid cylinder 005 and three high pressure gas-liquid cylinders 902, a hydraulic pump/hydraulic motor 908, five reversing valves, and a gas storage tank.
During the energy storage process, the hydraulic pump 908 drives the low pressure gas-liquid cylinder 005 to reciprocate, and through the control of the reversing valve 912, three high pressure gas-liquid cylinders 902 are alternately pressurized, and three high pressure gas-liquid cylinders 902 are used. The rotation is used for secondary compression and boosting to reach the rated high voltage.
When the high-pressure air of the gas storage tank releases energy, through the combined control of the reversing valve, the high-pressure oil-driven hydraulic motor 908 is first outputted by the three high-pressure gas-liquid cylinders 902, and when the air pressure in the gas storage tank drops to the medium-low pressure, the passage is passed. The reversing valve control outputs high pressure oil from the low pressure gas-liquid cylinder 005 to drive the hydraulic motor 908 to continue to operate.
The key concept of the invention patent includes the principle of an open accumulator and a secondary compression/expansion method to ensure that the compression/expansion process is an isothermal process and to increase the efficiency of the system.
Another compressed air energy storage system based on an open accumulator has a hydraulic pump/hydraulic motor 2340, a gas storage tank 2310 and 2311, two high pressure gas-liquid cylinders 2301 and 2302, and two low pressure gas-liquid cylinders. 2303 and 2304, hydraulic booster cylinder 2305, and reversing valve 2341 and the like.
During the energy storage process, the hydraulic pump 2340 outputs the reciprocating motion of the booster cylinder 2305 through the reversing valve 2341, and the low-pressure gas-liquid cylinders 2310 and 2311 are alternately charged to the high-pressure gas-liquid cylinders 2301 and 2302, and the boosting cylinder 2305 is charged. The output oil simultaneously drives the high-pressure gas-liquid cylinders 2301 and 2302 in turn to further compress the low-pressure air into a high-pressure gas to store energy to the gas storage tank.
In the first stage of the high-pressure air release energy of the gas storage tank, the high-pressure compressed air alternately drives the high-pressure gas-liquid cylinders 2301 and 2302 to output high-pressure oil to the boosting cylinder 2305, thereby driving the boosting cylinder 2305 to reciprocate, and the output high-pressure oil is exchanged. The hydraulic motor is driven to the valve 2341. When the air of the air tank drops to a medium and low pressure, the compressed air alternately drives the low pressure gas-liquid cylinders 2303 and 2304, and the medium and low pressure oil outputted by the compressed air is pressurized into the boosting cylinder 2305, and the high pressure oil output thereof passes through the reversing valve. The 2341 drives a hydraulic motor.
The key concept of the system still includes the principle of open accumulators, and also uses a two-stage compression/expansion method to ensure that the compression/expansion process is an isothermal process and improve the efficiency of the system. Compared with the solution, the lower pressure gas-liquid cylinder 005 is replaced by a more compact booster cylinder 2305. The control is also simplified.
Another solution given for this invention patent.
(Continued on page 61) Continuous automatic semi-automatic production line (especially crystal oscillator), welding machine, securities printing machine, far/offshore drilling platform, shipbuilding, hydraulic engineering construction and barrage, metallurgical equipment, advanced automobile and aircraft manufacturing Test units, simulation devices, special vehicles, robots, etc. In addition, Hanchen Jlaenchei) pressure relief cylinders can be used with confidence in stamping equipment and high voltage circuit breakers. Special Bureau accuracy, ultra-low-cost festival, super-frequency (400H3, very low-speed hydraulic servo cylinder is Hanchen Jlaenchei) company's most competitive products. Hanson Jlaenchei's two patented seals: servocop and servo-float, meet the needs of all applications between standard and static hydraulic bearings. In recent years, China's domestic metallurgical industry has introduced a number of German SMSDemag; Waldrich equipment. On these devices, the shadow of the Haenchen hydraulic cylinder can be seen everywhere. At present, Chinese domestic users use Hanchene's servofloat products, the highest vibration frequency in their application has reached 300Hz. Hansen haenche) company's single-out symmetrical cylinder is currently the world's high-end products without competitors. This product has won the favor of customers all over the world with its outstanding price/performance ratio. The Airbus A340 and the new A380's ground dynamic simulation system all use Hansen Jlaenchei's single-rod symmetrical cylinder and test cylinder, which has a maximum amplitude of 6.5 meters. In addition, Hanchen Jlaenche) hydraulic cylinders are also widely used in the German local Mercedes-Benz production line, Audi's door bending and other fields, the outstanding quality is undoubted. Hanchen haenche) test hydraulic cylinders have been successfully applied not only in the aerospace industry, but also in the aerospace industry, achieving a striking and decisive position.
More and more inspection and testing devices have become the fixed part of the 61st page of industrial production. The driving safety of the vehicle and the safety of the operation of the machine, the detection of the functional reliability of various products, the detection of the exhaust equipment and the function detection of the airbag are all typical of the hydraulic cylinders for testing and testing by Hanchen Jlaenclie. Application area. Hanchen haenchen) testing and testing hydraulic cylinders meet the requirements of the highest technical standards, which can be used to safely and reliably achieve regulated hydraulic drive. Hanchen Jlaenche) regards this requirement as its responsibility, so that its products have: extremely low friction; optimal sealing; excellent response characteristics; extreme bottom wear; extremely fast piston speed; very low starting force; Fatigue strength; long service life; higher cost performance. Hanchen haenche) excellent performance in testing and testing cylinders: force (from 2.6 to 6001 at 32MPa; power (high frequency up to 4111/8 up to 10001, high dynamic response); small installation size, reasonable area ratio, stroke Optional with piston diameter); work without oil leakage compensation pump.
Haenchen high-end sealing dynamic sealing principle: the annular gap seal is a non-contact seal. Due to the pressure difference, the oil is formed into a thin oil film through a small orifice, thus replacing the ordinary seal to achieve the sealing effect. It has a higher cost performance than the static pressure support. Since the contact seal and the dust seal are not subjected to pressure, the piston rod is guided by a friction-optimized guide element, so the starting friction force is very small over the entire pressure range. This ensures the high dynamics and long life of the servo cylinder.
Applications: Various tensile testing machines, multi-degree-of-freedom swinging tables, dynamic simulations of aircraft and automobiles and their parts.
Introduction of Hanchen (Shanghai) Hydraulic Equipment Co., Ltd. (Continued from page 59) 3 Inadequacies of the invention patent The insufficiency of this patent is the "isothermal" condition on how to ensure air compression/expansion, although some proposals have been made. However, there is no more in-depth quantitative analysis method. In fact, when the compression ratio is above 100, for example, the air is compressed from 0.1 MPa to 30 MPa, that is, when the compression ratio reaches 300, the patent only depends on the outer surface of the gas-liquid cylinder and the environment. Convective heat transfer is an "isothermal" condition that is difficult to meet air compression/expansion. How to solve this problem will be introduced in a follow-up article.
It can be seen that even if the "isothermal" condition cannot be satisfied, the volumetric energy density of the open accumulator is not lower than the adiabatic process, so that it can still achieve a good effect of an order of magnitude higher than the volumetric energy density of the closed accumulator.
Note: Enterprises interested in the secondary innovation and development of such products can contact the editorial department of this journal.
Centrifugal Pump is an important part of Electric Submersible Pump. In recent years, the technology of electric Submersible pump lifting is developing rapidly at home and abroad. In oil field production, especially in high water cut stage, most of the crude oil is produced by electric submersible pump. The electric submersible pump plays an important role in lifting technology of non flowing wells and wells with high yield in.
400series Petroleum Submersed Pump
Mud Pump Spare Part,Triplex Mud Pump,Petroleum Pump,Pump Transfer Gasoline Kerosene
Tianjin RongHeng Group LLC , https://www.ronghenggrouppump.com