CN2482602Y - Energy economizer with accumulator for variable frequency drive hydraulic elevator - Google Patents

Abstract

The utility model discloses an energy saver of a frequency conversion drive hydraulic elevator adopting an energy storage unit. An energy storage unit loop and an energy storage unit oil refilling loop are arranged in a main loop and a load loop in the normal frequency conversion hydraulic elevator. A main loop motor, a big pump/motor and a small pump/motor of the energy saver unit and the energy saver form a pressure-energy converter. When the elevator moves upwards, pressure stored in the energy saver is converted into the mechanical energy which acts on a motor shaft of the main loop, to provide an addition torque; when the elevator moves downwards, potential energy and kinetic energy of the elevator are converted into mechanical energy and pressure to stored in the energy saver to realize conversion and storage of the energy , and the output torque of the motor is reduced.

Description

Adopt the energy saving device of the variable frequency hydraulic elevator of accumulator

The utility model relates to the programme controlled device of hydraulic pressure, is a kind of energy saving device that adopts the variable frequency hydraulic elevator of accumulator.

Produce now from hudraulic lift, experienced the development course of valve control hydraulic system to the VFC hydraulic system.Valve control hudraulic lift is to use the most ripe hudraulic lift now, and it mainly is to use the motion speed that throttle grverning technology in the hydraulics is controlled hudraulic lift.Its maximum advantage is exactly that system is succinct, and control is convenient, but shortcoming is obvious: adopt the spill losses of throttle grverning system bigger, particularly the descending whole potential energy of elevator all are lost in throttle orifice, cause system effectiveness lower, and the fluid temperature rise is very fast; Cause to use when frequently moving expensive cooling system to reduce the rising of temperature; And the rising of oil temperature also makes and the speed controlling unstable properties of elevator must adopt the controlling method of more complicated to obtain good control performance.

The hudraulic lift of conventional frequency conversion drive is by adopting the variable voltage variable frequency technology to control the rotating speed of three-phase AC asynchronous motor, thereby the output/input flow rate of control quantitative hydraulic pump/motor, reach and control the oil hydraulic cylinder jacking car motion speed that makes progress according to certain rules, perhaps control the purpose of car downstream rate.

As shown in Figure 1, Chang Gui variable frequency hydraulic elevator simple working principle is as follows:

1) up

After receiving the up calling signal in stop or the sedan-chair, computer control detects controller 11 and sends two paths of signals, and one the tunnel is the pwm signal 16 of control frequency variator; One the tunnel is the positive veer signal 17 of motor; The Ac 21 that frequency variator 1 produces corresponding frequencies and voltage according to the control signal 16 of input drives asynchronous motors 3 and drives pump/motors 2 rotation pressure oil output, 14 one-way valves that back down in the solenoid valve 7 by the road, thus promote upwards operation of car; Before elevator starter, by pressure transducer 12 major loop pressure, deliver to computer control detection unit 11 by signaling line 19, compare with the value of setting of being scheduled in the software, determine to load the moment of ideal speed curve.Simultaneously, the photoelectric encoder 4 of motor reel side detects rotating speed of motor and tach signal is fed back to frequency variator, constitutes closed-loop vector control.When elevator pulled in, computer control detection unit 11 sent stop sign for frequency variator 1, and motor 3 rotating speeds reduce to zero, and the outlet pressure of pump/motor 2 also reduces rapidly, leaned on the deadweight of car 10 that the one-way valve in the solenoid valve 7 is turn-offed, and elevator stops.If major loop pressure surpasses the value of setting of safety valve 9, the pressure oil of then big pump/motor output is by pipeline 15, safety valve 9 bypass oil sump tanks 43.

2) descending

After receiving the descending calling signal in stop or the sedan-chair, computer control detection unit 11 is at first exported control signal 17 and is made frequency variator drive motor 3 forward low-speed runnings, give system's repairing, pump/motor 2 export pipelines 14,15 pressure are raise rapidly, when the outlet pressure that detects pump/motor 2 when pressure transducer 12 reaches setting value, computer control detection unit 11 sends three road signals, and one the tunnel is the electromagnet energising of control electromagnetic valve 7, and solenoid valve 7 is opened; One the tunnel is the sense of rotation signal 17 of motor, drives asynchronous motor 3 and carries out the transition to antiport from the forward low-speed running; One the tunnel is the pwm signal 16 of control frequency variator 1, frequency variator 1 provides corresponding braking moment to control the speed that plunger descends according to the control signal 16 of input to motor 3, this moment, motor changed the operation of generator state into by electric motor state, and the energy that is produced returns the electrical network (not shown) through the regenerative braking unit; When elevator pulled in, computer control detection unit 11 made solenoid valve 7 electromagnet outages, and solenoid valve 7 cuts out, for avoiding impacting, during frequency variator 1 drive motor 3 low speed and reverses, wait that car 10 is complete to allow frequency variator 1 stop when slack; In motor 3 Umklapp processes pump/motor 2 through one-way valve 8, pipeline 25 and pipeline 15 from fuel tank 43 oil suction to keep on the go.

In car 10 upper and lower runnings, the photoelectric code disk 24 of car speed signal on car 10 detects, and feeds back to computer control detection unit 11 in real time by signaling line 22 and notes, and be presented in real time on the computer screen, for experimental analysis.Simultaneously the speed feedback of car also can constitute car speed and feeds back big closed loop car speed is controlled.

As a kind of variable speed volumetric speed control mode, thereby frequency control of motor speed can provide flow that the loss of system's overflow is dropped to bottom line by the needs of system, compare with valve control hydraulic elevator system, no matter how load changes this frequency conversion drive volumetric speed control hydraulic elevator system, input power can both adapt to the variation of loading demand, therefore can reduce hudraulic lift uplink and downlink energy consumption significantly, improve the efficient of system, the temperature rise of system is reduced significantly.

Selection of components also must be selected by the maximum consumption of power principle in the same frequency conversion drive volumetric speed control hydraulic elevator system with valve control system, be exactly under the prerequisite of same design parameter, frequency conversion drive speed control system with adjustable displacement power demand element is consistent with the ultimate bearing capacity of valve control system power demand element, and promptly it can not reduce system's installed power; And more powerful frequency variator costs an arm and a leg in the production application at present, because less in batches, this just makes standard frequency conversion (VVVF) hydraulic control system cost higher.Adopt hudraulic lift motor 3 in descending process of frequency conversion drive to do generator generation electric energy in addition, this moment is if will then must reach relevant filtering with an inverter to reach purpose of energy saving with the electric energy feedback grid that produces, rectification circuit constitutes feedback circuit, like this, one has increased system again constitutes cost, two come the electric energy quality of feedback to depend on feedback circuit, the raising of quality means the increase of feedback circuit complexity and cost, the descending energy recovery of elevator is the key that reduces VFC hudraulic lift energy consumption, if can not finely solve, though then VFC hudraulic lift energy consumption is littler than valve control system, but compare with towed elevator, still bigger.

The purpose of this utility model is: the energy saving device that adopts the variable frequency hydraulic elevator of accumulator, can solve the descending energy recovery of variable frequency hydraulic elevator in the background technique field, and discharge in the ascending for elevator process, can reduce the energy consumption and the installed power of hudraulic lift.

In order to achieve the above object, the technical solution adopted in the utility model is as follows:

It comprises the AC vector frequency variator, big pump/motor, AC asynchronous motor, the photoelectric encoder of motor shaft side, plunger case and plunger, major loop solenoid valve, the empty one-way valve of the anti-suction of major loop, the major loop relief valve, elevator cab, control detection unit, pressure transducer, the photoelectric encoder that tests the speed on the car, hoistway and guide rail, major loop and load circuit that the coupling of AC asynchronous motor and big pump/motor is formed.It also comprises little pump/motor, anti-empty one-way valve, the secondary circuit solenoid valve inhaled of secondary circuit, bag type accumulator, repairing AC asynchronous motor, slippage pump, the anti-one-way valve that pours in down a chimney of feed circuit, auxiliary accumulator loop and the accumulator feed circuit of forming with the feed circuit relief valve; Little pump/motor is connected with coupling with AC asynchronous motor; little pump/motor one tunnel connects secondary circuit and prevents inhaling empty one-way valve; another kind connects bag type accumulator through bypass circuit electromagnetic valve; auxiliary and feed circuit relief valve one tunnel prevents that through feed circuit pouring in down a chimney one-way valve connects slippage pump; another road connects bag type accumulator, and the computer control detection unit connects the secondary circuit solenoid valve through control signal line.

The utility model has the advantages that: it constitutes pressure one energy conversion device jointly by major loop motor, big pump/motor and the little pump/motor of accumulator loop and accumulator.When elevator cab is up, the pressure that stores in the accumulator can be converted to mechanical energy by little pump/motor provides additional moment for the axle of major loop motor or big pump/motor; And when elevator cab is descending, car potential energy and kinetic energy are converted to mechanical energy by big pump/motor, by little pump/motor mechanical energy being converted to pressure again can be stored in the accumulator, thereby realizes the mutual conversion and the storage of energy stream, has reduced the output torque of motor.The utility model not only has frequency changing driving system efficient height, the advantage of less energy consumption, but also reduced the installed power of hudraulic lift significantly.

The utility model is described in further detail below in conjunction with accompanying drawing.

Fig. 1 is conventional variable frequency hydraulic elevator schematic diagram;

Fig. 2 is for adopting the variable frequency hydraulic energy-saving device of elevator schematic diagram of accumulator.

As shown in Figure 2, it comprises AC vector frequency variator 1, big pump/motor 2, AC asynchronous motor 3, the photoelectric encoder 4 of motor shaft side, plunger case and plunger 5,6, major loop solenoid valve 7, anti-empty one-way valve 8, the major loop relief valve 9 inhaled of major loop, elevator cab 10, computer control detection unit 11, pressure transducer 12, the photoelectric encoder 23 that tests the speed on the car, hoistway and guide rail 24, major loop and load circuit that the coupling 26 of AC asynchronous motor 3 and big pump/motor 2 is formed.It also comprises little pump/motor 27, the empty one-way valve 28 of the anti-suction of secondary circuit, secondary circuit solenoid valve 29, bag type accumulator 30, repairing AC asynchronous motor 36, slippage pump 37, the anti-one-way valve 38 that pours in down a chimney of feed circuit, auxiliary accumulator loop and the accumulator feed circuit of forming with feed circuit relief valve 39; Little pump/motor 27 is connected with AC asynchronous motor 3 usefulness coupling 42; little pump/motor 27 one tunnel connects secondary circuit and prevents inhaling empty one-way valve 28; another kind connects bag type accumulator 30 through bypass circuit electromagnetic valve 29; auxiliary and feed circuit relief valve 39 one tunnel prevents that through feed circuit pouring in down a chimney one-way valve 38 connects slippage pump 37; another road connects bag type accumulator 30, and computer control detection unit 11 connects secondary circuit solenoid valve 29 through control signal line 31.

Major loop motor 3, big pump/motor 2 and the little pump/motor 27 of accumulator loop and accumulator 30 common formation pressure-energy conversion devices.In the whole service process, play the function served as bridge of an energy transfer; In the up process of elevator cab, it can be converted to mechanical energy by little pump/motor 27 with the pressure that stores in the accumulator and provide additional moment for the axle of major loop motor 3 or big pump/motor 2; And when descending, it is converted to mechanical energy with car potential energy and kinetic energy by big pump/motor 2, by little pump/motor 27 mechanical energy is converted to pressure again and can be stored in the accumulator 30, thereby realize mutual conversion and the storage that energy flows, reach energy-conservation and realize the purpose that installed power reduces.

Divide two operating modes of uplink and downlink to be described in detail the principle of the variable frequency hydraulic elevator energy-saving control system of band accumulator below; Because the inherent characteristic of bag type accumulator work, we also will focus on the influence (narration before, we suppose motor forward rotation corresponding ascending for elevator, otherwise corresponding elevator descending) of elevator load situation to native system actual motion state.Up process

After receiving the up calling signal in stop or the sedan-chair, computer control detection unit 11 sends three road signals, and one the tunnel is the pwm signal 16 of control frequency variator; One the tunnel is the turn signal 17 of motor; Another road is the switching signal 31 of control electromagnetic valve 29; Frequency variator 1 is made big pump according to the ac signal 21 driving asynchronous motors 3 output torques drive pump/motors 2 of control signal 16 generation corresponding frequencies of importing and voltage and is rotated in the forward pressure oil output in the major loop, 14 one-way valves that back down in the solenoid valve 7 upwards move thereby promote car 10 by the road; Before elevator starter, by pressure transducer 12 major loop pressure, deliver to computer control detection unit 11 by signaling line 19, compare with the value of setting of being scheduled in the software, determine to load the moment of ideal speed curve.The electromagnet of the solenoid valve 29 of accumulator loop energising simultaneously, solenoid valve 29 is opened, pressure oil liquid in the accumulator 30 enters the little pump/motor 27 of little pump/motor 27 promotions by pipeline 32,33,35 and does the motor rotation, the pressure in the accumulator 30 can be converted into the additional drives moment that acts on motor 3 or big pump/motor 2 running shafts overcome load circuit resisting moment driving ascending for elevator jointly.In the whole service process, the photoelectric encoder 4 of 3 sides of motor detects the rotating speed of motor 3 and tach signal 20 is fed back to frequency variator 1, compare with desirable velocity curve, by the software algorithm in the computer control unit 11, assurance elevator running velocity curve is accurately followed the tracks of ideal curve, constitute closed-loop vector control, reach the effect of comfortable operation.Photoelectric encoder 23 on the car detects elevator actual motion speed, feeds back to computer control detection unit 11 in real time and notes, and be presented in real time on the computer screen, for experimental analysis or participation control.When the deceleration point signal triggering in the hoistway, frequency variator 1 control motor 3 increases retarding torque gradually, and when making motor 3 with a certain less invariablenes turning speed, elevator enters the flat bed section; When car 13 when stopping stop, dry reed switch in the hoistway provides stop signal, computer control unit 11 sends stop sign for frequency variator 1, make the outage of solenoid valve 29 electromagnet simultaneously, solenoid valve 29 cuts out, and motor 3 rotating speeds reduce to zero, and the outlet pressure of big pump/motor 2 also reduces rapidly, deadweight by car 10 is turn-offed the one-way valve in the solenoid valve 7, and elevator stops.If major loop pressure surpasses safety valve.9 the value of setting, the pressure oil of then big pump/motor output is by pipeline 15,25, safety valve 9 bypass oil sump tanks 43.

In whole up process, accumulator 30 all is in the stage of releasing energy, fluid discharge, air bag volumetric expansion, accumulator internal pressure constantly descend, therefore it also constantly changes to the additional drives moment that motor 3 or big pump/motor 2 running shafts are provided by little pump/motor 27 thereupon, and this is that the intrinsic performance characteristic of accumulator determines; (because the difference of load, the resisting moment of load circuit is also different), focus in two kinds of situation here because the variation of different motor torque in whole up process of load: (1): underloading (containing zero load) is up

The oil liquid pressure that stores in the accumulator 30 when just starting is the highest, its additional drives moment in the generation that rotation shaft side transforms of motor 3 or big pump/motor 2 is also maximum, this moment is if car 10 is a underloading, the additional drives moment that accumulator loop provides is big than the load circuit resisting moment, impact for avoiding ascending for elevator to start, therefore when light-load starting, motor 3 must provide the resisting moment of load circuit and the torque difference between the accumulator loop additional drives moment as retarding torque under frequency variator 1 control, make car static, and then reduce retarding torque gradually, it is up by desirable velocity curve to make pump/motor 2 promote car 10 as pumping function postive direction rotation output hydraulic oil.Along with the up accumulator loop pressure of car 10 constantly reduces, the additional drives moment that it can provide also constantly reduces, and motor 3 is subjected to frequency variator 1 control to provide the Electromagnetic Drive torque to promote car 10 jointly by desirable curve motion when additional drives moment has been not enough to promote car 10 by desirable curve motion.(2): heavy duty is up

Compare because car 10 is full load with underloading is up, the resisting moment of load circuit is bigger, therefore the torque difference between load circuit and the accumulator loop is less when just starting, the required retarding torque that provides is also corresponding reduces for motor 3, compare with the up startup of underloading, the dynamic and static performance of heavily loaded up startup makes moderate progress.Up along with car 10, motor 3 is subjected to frequency variator 1 control to provide the Electromagnetic Drive torque to promote car jointly by desirable curve motion.When elevator moved on the high building course, this moment, accumulator loop pressure was lower, and the additional drives moment that it can provide is relatively little, and load circuit is in big resisting moment state, and the required Electromagnetic Drive moment that provides of motor is bigger; Particularly when elevator operation during near the top, in this moment accumulator pressure near Minimum operating pressure, the additional drives moment minimum that it can provide, then motor 3 needs provide the driving moment of maximum under the control of frequency variator 1.Motor 3 is in the state of operating at full capacity this moment.Descending process

Descending more up process is more complicated: oil liquid pressure reduces in the pipeline 14,15 because the internal leakage of big pump/motor 2 causes, it is special when the stand-by period is longer, oil liquid pressure even low in the pipeline 14,15 to tank pressure, and oil liquid pressure is an induced pressure in the pipeline 13, consider the factors such as compressibility of fluid simultaneously, this moment is if still take and up same control strategy, then can produce downward impact because of the pressure difference at solenoid valve 7 two ends when moment elevator cab that solenoid valve 7 is opened when descending the startup.Therefore produce downward impact when avoiding descending startups, behind the descending calling signal of system in receiving stop or sedan-chair, computer control detection unit 11 sends the positive rotaring signal 17 of motor 3 low speed earlier, motor 3 low speed just change, big pump/motor 2 is done pump operating mode pressure oil output, and one-way valve 28 is used for guaranteeing that accumulator loop pump/motor 27 can not inhale sky when motor 3 is just changeing; The pressure of pressure transducer 12 real-time signal pipings 14 also feeds back to computer control detection unit 11, after the pressure for the treatment of pipeline 14 reaches the equinoctial point that control software sets, computer control detection unit 11 is closed the positive rotaring signal of motor, send the signal 18 of opening solenoid valve 7, because damping function, this valve is slowly opened; Simultaneous computer control detection unit 11 sends the pwm signal 16 and the motor backward rotation signal 17 of control frequency variator, makes motor 3 backward rotation, and elevator is descending; In the whole service process, the pressure oil of load circuit enters the big pump/motor 2 of big pump/motor 2 promotions by pipeline 13,14 and does the motor operating mode, the pressure of load circuit can be converted into the additional drives moment that acts on motor 3 or little pump/motor 27 running shafts, and little pump/motor 27 is done the pump operating mode under the common driving of big pump/motor 2 and motor 3, charged pressure oil in accumulator 30, the descending energy of storage elevator; The photoelectric encoder 4 of 3 sides of motor detects the rotating speed of motor 3 and tach signal 20 is fed back to frequency variator 1 simultaneously, compare with desirable velocity curve, by the software algorithm in the computer control detection unit 11, assurance elevator running velocity curve is accurately followed the tracks of ideal curve, constitute closed-loop vector control, reach the effect of comfortable operation.When the deceleration point signal triggering in the hoistway, frequency variator 1 control motor 3 increases retarding torque gradually, and when making motor 3 with a certain less invariablenes turning speed, elevator enters the flat bed section; When car 10 when stopping stop, dry reed switch in the hoistway provides stop signal, computer control unit 11 sends stop sign for frequency variator 1, make the outage of solenoid valve 7 electromagnet simultaneously, solenoid valve 7 cuts out, and motor 3 rotating speeds reduce to zero, and the outlet pressure of little pump/motor 27 reduces rapidly, the pressure difference at solenoid valve 29 two ends makes it to close, and elevator stops.The purpose that one-way valve 28 is set is to produce emptying phenomenon when preventing little pump/motor low speed rotation, can pass through fuel tank 43, one-way valve 27, and pipeline 34 oil suctions enter the mouth to little pump/motor.Being provided with of safety valve 39 can be when the secondary circuit overpressure, and the fluid of accumulator is by pipeline 40, safety valve 39 oil sump tanks.

In whole descending process, accumulator 30 all is in the stored energy stage; Fluid enters accumulator, gas in the compressing gasbag, and pressure raises, so it also constantly changes to the resisting moment that motor 3 or big pump/motor 2 running shafts are provided by little pump/motor 27 thereupon; Similar with the upstream analyzing process, herein also according to the split-phase motor 4 torques variation in two kinds of situation of load difference: (1): heavy duty is descending

The oil liquid pressure that stores in the accumulator 30 when just starting is minimum, its resisting moment in the generation that rotation shaft side transforms of motor 3 or big pump/motor 2 is also minimum, and this moment, car was fully loaded, the additional drives moment that load circuit provides is relatively large, therefore when the descending process of heavy duty has just started, for avoiding the descending overshoot of elevator, motor 3 must provide the resisting moment of accumulator loop and the torque difference between the load circuit additional drives moment as retarding torque under frequency variator 1 control, make car static, and then reduce retarding torque gradually, make big pump/motor 2 make car 10 descending by desirable velocity curve as motor function counter-rotation input hydraulic pressure oil.Along with the descending accumulator loop pressure of car 10 constantly raises, the resisting moment that it provided also constantly increases, the additional drives moment that provides when load circuit deficiency so that car 10 during by desirable curve motion motor 3 be subjected to frequency variator 1 control to provide the Electromagnetic Drive torque to promote car 10 jointly by desirable curve motion.(2): underloading (containing zero load) is descending

With fully loaded descending comparing because car 10 is zero load, the additional drives moment of load circuit is less, therefore the torque difference between load circuit and the accumulator loop is less when descending process has just started, the required retarding torque that provides is also corresponding reduces for motor 3, compare with the descending startup of heavy duty, the dynamic and static performance of the descending startup of underloading makes moderate progress.

Descending along with car 10, motor 3 is subjected to frequency variator 1 control to provide the Electromagnetic Drive torque to promote car jointly by desirable curve motion.When elevator moved under the lowrise course, this moment, accumulator loop pressure was higher, and the resisting moment that it provided is relatively large, and load circuit is a underloading, and the additional drives moment that is provided is less, and the motor 3 required Electromagnetic Drive moments that provide are bigger; Particularly when elevator operation during near the bottom, in this moment accumulator pressure near Maximum operating pressure, the resisting moment maximum that it provided, then motor 3 needs the driving moment that provide maximum under the control of frequency variator 1.Motor 3 is in the state of operating at full capacity this moment.

According to above analysis as seen, the key of this project energy saving, reduction installed power just is to have introduced the pressure energy conversion equipment, and with the conversion Conversion of energy be the additional drives moment that acts on 3 sides of motor, thereby significantly reduced the output torque of motor, reduced power of electric motor; Motor 3, the big pump/motor 2 of major loop and the little pump/motor 27 of accumulator are operated in four quadrants, thereby have utilized the ability to work of motor 3 fully; The hydraulic volume flow control circuit that adopts ac variable speed technology to constitute belongs to the power adaptive system, and the system effectiveness height has reduced the temperature rise of the operation energy consumption and the fluid of elevator, has avoided using expensive cooler; The reduction of frequency variator and motor capacity not only makes the cost of system obtain reduction, and has saved the expense of user on electric wiring.And this project focus on how determining the determining of the choosing of each the operation point parameter of accumulator 6 in the accumulator loop such as accumulator loop pump/motor discharge capacity, motor power (output), charging pressure of accumulator p ₀, the minimum charge pressure p of accumulator ₁, the highest charge pressure p of accumulator ₂Deng; Can see also that simultaneously up and descending these the two kinds of operating modes of elevator underloading near the bottom time of elevator heavy duty near the top time are comparison opposite extreme situations, motor 3 all will be with running at full capacity under these two kinds of situations.

From the angle of the installed power that reduces system to greatest extent, determine the accumulator running parameter based on following primitive rule, various frictional losses and the pump/motor of wherein having ignored system leak the volumetric loss that causes:

1) the accumulator 30 average power W that can provide _AverageBe the fully loaded required average power W of elevator _MaxWith the unloaded required average power W of elevator _MinHalf of sum, that is:

W _average＝(W _max＋W _min)/2

Wherein: W _Max=p ₂A v

W _min＝p ₁A v $W_{\mathrm{average}}=\frac{{\∫}_0^t{p}_a{Q}_a\mathrm{dt}}{t}=\frac{{\∫}_0^t{p}_a\frac{\mathrm{dV}}{\mathrm{dt}}*\mathrm{dt}}{t}=\frac{{\∫}_{V\left(0\right)}^{V\left(t\right)}{p}_a\mathrm{dV}}{t}$

In the formula: A---the cross-section area of plunger 6;

The mean velocity of v---plunger 6;

The time of t---plunger 6 one way operation;

p _a---middle pressure; p _a=(p ₁+ p ₂)/2;

Q _a---mean flowrate;

The gas volume of V---accumulator 30 in working order.

2) according to the experience that obtains in making up frequency conversion (VVVF) control hudraulic lift: when motor power (output) met the demands, the output torque of motor but might not be satisfied, and caused the moment overload; Directly reflection is exactly the motor current overload.Therefore consider the equalising torque relation under two kinds of operating modes of motor 4 fully loadeds:

Underloading is descending during (1) near the bottom $\frac{{p_d}^{*}{\mathrm{<figure-callout\; id="2"\; label="q\; pth"\; filenames="Y0122801800131.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{pth}}}{2\mathrm{\&pi;}}+T_{\max }=\frac{{{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="Y0122801800131.png"\; state="\{\{state\}\}">p</figure-callout>}}_2}^{*}{\mathrm{<figure-callout\; id="2"\; label="q\; sth"\; filenames="Y0122801800131.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{sth}}}{2\mathrm{\&pi;}}$

Fully loaded up during (2) near the top $\frac{{p_u}^{*}{\mathrm{<figure-callout\; id="2"\; label="q\; pth"\; filenames="Y0122801800131.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{pth}}}{2\mathrm{\&pi;}}=\frac{{p_l}^{*}{\mathrm{<figure-callout\; id="2"\; label="q\; sth"\; filenames="Y0122801800131.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{sth}}}{2\mathrm{\&pi;}}+T_{\max }$

In the formula: p _d---pump/motor 2 inlet pressures when underloading is descending;

p _u---heavily loaded pump/motor 2 outlet pressures when up;

T _Max---the motor maximum output torque;

q _Pth---the discharge capacity of pump/motor 2;

q _Sth---the discharge capacity of pump/motor 27;

On the basis of these two primitive rules as can be known in the native system:

W _average＋W _motor＝W _maxW _motor＝W _max-W _average

W _motor＝(W _max-W _min)/2

In the formula: W _Motor---the rated power of motor 3;

The installed power that this shows system has significantly reduced.Because the existence of pump/motor element volumetric efficiency, and the internal leakage of solenoid valve 29 make each operation period accumulator 30 all will lose partial volume, moving several back accumulator 30 with blank thus; For avoiding this phenomenon a recharging oil device to occur then must in system, setting up the volume that loses is compensated.Recharging oil device also has another critical function simultaneously, promptly satisfies accumulator oil-filled needs 30 first time, and the charge pressure value so just need not extra oil-filled equipment by safety valve 39 controls.Therefore how reasonably the design and use recharging oil device also becomes an emphasis of system design.

Start recharging oil device simultaneously when each elevator moves accumulator 30 is carried out the process repairing, the repairing process also stopped when elevator stopped.Repairing is based on elevator with the Selection and Design of oil hydraulic pump and converts at the volume of an one-stroke accumulator loop loss in service and obtain, and is that example provides simple conversion process with up process below.

Elevator is the 2 required liquid capacity Vp that provide from ground floor to the attic pump/motor:

V _p＝s·A/η _pv

Convert accumulator loop pump/motor 27 output fluid volume V s:

V _s＝(V _p/η _sv)*(q _sth/q _pth)

Accumulator loop is Vx through pump/motor 27 leakage volumes in this process: $V_x=V_s-\frac{\mathrm{sA}{q}_{\mathrm{sth}}}{q_{\mathrm{pth}}}$ The discharge capacity that accumulator loop leakage volume is converted is qx: $q_x=\frac{V_x}{V_p/q_{\mathrm{pth}}}=\frac{q_{\mathrm{sth}}}{{\mathrm{\&eta;}}_{\mathrm{sv}}}-{\mathrm{\&eta;}}_{\mathrm{mv}}{q}_{\mathrm{sth}}$ In the formula: η m _v---the volumetric efficiency of pump/motor 2;

η _Sv---the volumetric efficiency of pump/motor 27;

Claims (1)

1. adopt the energy saving device of the variable frequency hydraulic elevator of accumulator, it comprises AC vector frequency variator [1], big pump/motor [2], AC asynchronous motor [3], the photoelectric encoder of motor shaft side [4], plunger case and plunger [5,6], major loop solenoid valve [7], the anti-empty one-way valve [8] of inhaling of major loop, major loop relief valve [9], elevator cab [10], computer control detection unit [11], pressure transducer [12], pressure sensor signal line [19], the photoelectric encoder that tests the speed [23] on the car, hoistway and guide rail [24], major loop and load circuit that the coupling [26] of AC asynchronous motor [3] and big pump/motor [2] is formed; It is characterized in that: also comprise little pump/motor [27], the anti-empty one-way valve [28] of inhaling of secondary circuit, secondary circuit solenoid valve [29], bag type accumulator [30], repairing AC asynchronous motor [36], slippage pump [37], the anti-one-way valve [38] that pours in down a chimney of feed circuit, auxiliary accumulator loop and the accumulator feed circuit of forming with feed circuit relief valve [39]; Little pump/motor [27] is connected with coupling [42] with AC asynchronous motor [3]; little pump/motor [27] a tunnel connects secondary circuit and prevents inhaling empty one-way valve [28]; another kind connects bag type accumulator [30] through bypass circuit electromagnetic valve [29]; auxiliary and feed circuit relief valve [39] a tunnel prevents that through feed circuit pouring in down a chimney one-way valve [38] connects slippage pump [37]; another road connects bag type accumulator [30], and computer control detection unit [11] connects secondary circuit solenoid valve [29] through control signal line [31].

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