Computer Simulation Aided Study of a Real-time Energy Benchmarking Parameter for Lift Systems under different Traffic Control Schemes

Abstract

At present, there are benchmarking parameters to assess the energy performance of lifts, e.g. one in Germany adopted by VDI (4707-1/2), one internationally published by ISO (BS EN ISO 25745-2:2015), and the other in Hong Kong adopted by The Hong Kong Special Administrative Region (HKSAR) Government. These parameters are mainly checking and governing the energy consumed by a lift drive without considering real time passenger demands and traffic conditions, the one in Hong Kong pinpointing a fully loaded up-journey under rated speed while the two in Europe pinpointing a round trip, bottom floor to top floor and return with an empty car, though including energy consumed by lighting, displays, ventilation etc. A holistic normalization method (So et al 2005, Lam et al 2006) was developed more than ten years ago by the first author of this article, which can simultaneously assess both drive efficiency and traffic control performance, termed <J/kg-m> which is the name of the parameter measured in unit, J/kgm, and is now adopted by the HKSAR Government as a good practice in the Technical Guidelines of the Energy Code, but not yet enforced in the mandatory code. In Europe, the energy unit of Wh has been used but here, the unit of Joule (J), i.e. Ws, is adopted to discriminate the difference between the two concepts. In this article, such parameter is evaluated under different drives and lift traffic control scenarios by using computer simulations, with the aim of arriving at a reasonable figure for benchmarking an energy efficient lift system with both an efficient drive as well as an efficient supervisory traffic control. This parameter could also compare the performance of different types of intelligent car dispatcher.