WP6-Brochure-E4 brochure - ELA European Lift Association.

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In traction lifts, the car is suspended by ropes wrapped around a sheave that is driven by an electric motor. The weight of the car is usually balanced by a counterweight that equals the mass of the car plus 45% to 50% of the rated load. The purpose of the counterweight is to make sure a sufficient tension is maintained in the suspension system so as to ensure adequate traction is developed between ropes/belts and drive sheave. In addition, it maintains a near constant potential energy level in the system as a whole, heavily reducing energy consumption. Traditionally, electric traction lifts were equipped with DC motors due to their easy controllability, but the development of variable frequency drives led to the introduction of the now prevalent AC induction motors or permanent magnet DC motors. These drives provide excellent ride conditions, with smooth acceleration and deceleration and high levelling accuracy. There are two main types of traction lifts: geared and gearless. Geared lifts use a reduction gear to reduce the speed of the car while in gearless lifts the sheave is directly coupled to the motor. Figure 2‐2. Simplified representation of a typical conventional traction lift installation (source: Fraunhofer ISI) 8
Figure 2‐3. Configuration of Geared traction lift machineroom (source: Mitsubishi) Figure 2‐4. Configuration of Gearless traction lift machine‐room (source: Mitsubishi) 2.1.1 Geared Lifts Geared lifts are typically used in mid‐rise applications (7 to 20 floors) where high speed is not a major concern (typical speeds range from 0,1 m/s to 2,5 m/s). The reduction gear allows the use of smaller, less expensive motors that can thus work at higher speeds, producing the desired torque. The machine typically consists of the motor, brake, gearbox and traction sheave. The most commonly used reduction gear is still of the worm type, comprising a worm and a worm wheel. The reduction ratio of the gear is given by dividing the number of teeth on the wheel by the number of starts on the worm. These worm gears are relatively inefficient and are, in some few cases, being replaced by helical gears. 2.1.2 Gearless Lifts In Gearless lifts, the sheave is driven directly by the motor, thus eliminating losses in the gear train. This type of lift has normally been used in high rise applications with nominal speeds between 2,5 m/s and 10 m/s. However, recent developments have made it available for use in low rise buildings and for speeds lower than 2,5 m/s. The machine in gearless lifts consists of a motor, traction sheave and brake. Since the motor is directly coupled to the traction sheave, there are no transmission losses and they both rotate at the same speed. The motor must, therefore, rotate at a very low speed – the rope speed is equal to the circumference of the sheave multiplied by the rotational speed of the motor. For example, for a rated speed of 5 m/s and a sheave diameter of 750 mm the required motor speed is of only 128 rpm. 2.1.3 Machine Roomless Lifts Saving highly valued construction space has always been a concern for lift designers and it has been the driver of highly innovative technological solutions. Conventionally, all lifts, either 9
Page 1 and 2: E4 ENERGY EFFICIENT ELEVATORS AND E
Page 3 and 4: Contents 1 Introduction ...........
Page 5 and 6: 1 Introduction Means of vertical tr
Page 7: 2 Lift and Escalator Technologies T
Page 11 and 12: Some manufacturers have gone even f
Page 13 and 14: • Conventional hydraulic units do
Page 15 and 16: [2] Sachs, H., “Opportunities for
Page 17 and 18: High efficiency motors are typicall
Page 19 and 20: Figure 3‐3. Effect of load on pow
Page 21 and 22: If the linear motor is mounted on t
Page 23 and 24: 3 Phase AC input 50 Hz AC/DC Conver
Page 25 and 26: preventing the car from falling. Ty
Page 27 and 28: Figure 3‐14. Regenerative operati
Page 29 and 30: occupied by lift support systems. A
Page 31 and 32: Figure 3‐19. Possible configurati
Page 33 and 34: After the introduction of relay log
Page 35 and 36: It is evident that the way lifts ar
Page 37 and 38: When combined with hall call contro
Page 39 and 40: of the torque of the 1:1 roping sch
Page 41 and 42: times as quickly as a 720 mm sheave
Page 43 and 44: LEDs are also a very efficient solu
Page 45 and 46: • Car electronics • Light curta
Page 47 and 48: The major cause of energy consumpti
Page 49 and 50: 3.9 Efficient Escalators and Moving
Page 51 and 52: These bearings feature optimised in
Page 53 and 54: 4 Market Characterisation As part o
Page 55 and 56: Figure 4‐2. Lift Distribution acc
Page 57 and 58: The next three figures show the lif
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5 Results of the Monitoring Campaig
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the lift, but does not include addi
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Where, E standby Standby Energy use
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Figure 5‐4 shows a typical cycle
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Figure 5‐6. Travel cycle consumpt
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Figure 5‐9. Measured standby powe
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Figure 5‐12. Annual Energy consum
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Figure 5‐16. Annual Energy consum
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Figure 5‐19. Annual electricity c
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6.1.1 Determination of the average
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Where, P mech E cycle η system h v
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6.2. Electricity consumption of lif
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6.3. Estimation of potential saving
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The results show that overall savin
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6.5. Estimation of Savings Potentia
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Identification of stakeholders and
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Table 7‐1. Categories of stakehol
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esults were presented and discussed
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We also asked which stakeholder inf
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not rate an item. Reasons for non
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Further barriers We asked responden
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Raising awareness Setting a standar
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Further topics This section address
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The scope of the present study is o
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Table 7‐4. Energy efficiency: Spe
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10 Check system architecture Ropes
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17 Avoid stalled motor door operato
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24 Switch off other lift components
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passenger arrives. However, an addi
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