• ENE-CAS-6
  • 空壓系統
  • 系統設計、安裝或更新-使用精密控制系統
  • In the majority of IPPC applications, CASs are multi-compressor installations. The energy efficiency of such multi-compressor installations can be significantly improved by CAS master controls, which exchange operational data with the compressors and partly or fully control the operational modes of the individual compressors.
    The efficiency of such master controls strongly depends on the capabilities of the communication link, which can range from simple floating relay contacts to networks using automation protocols. An increase in communication capabilities offers more degrees of freedom to retrieve operational data from the compressor, to control the operational mode of the individual compressors and to optimise the overall energy consumption of a CAS.
    The control strategy of the master control has to take into account the characteristics of the individual compressors, in particular their control mode. Some remarks on control modes of common compressor types are given to illustrate this. The most commonly used control modes of individual compressors are:
    ●switching between load, idle and stop, and
    ●frequency control.
    The main features of sophisticated compressor and master controls can be summarised a s follows:
    ●advanced communication features (e.g. based on automation protocols)
    ●comprehensive access of the C AS master control to operational data of individual compressors
    ●comprehensive control of all compressor operation modes by the CAS master control
    ●self-learning optimisation of master control strategy, including recognition of CAS properties
    ●determination and activation of highly energy efficient combinations of loaded, idling and stopped compressors and transitions between these states to match total free air delivery (FAD) demand
    ●effective control of variable frequency compressors to compensate short term fluctuations in FAD demand avoiding inefficient long term operation at constant speed, in particular at low frequencies
    ●minimisation of switching frequencies and idle operation of fixed speed compressors
    ●sophisticated prediction methods and models for total FAD demand including recognition of cyclic demand patterns (daily or weekly shift and workspace patterns, etc.)
    ●additional functions like remote monitoring, plant data collection, maintenance planning, teleservice and/or supply of preprocessed operational data via web servers
    ●control of other CAS components in addition to compressors.


  • None.

  • According to the SAVE study, the retrofit of sophisticated control systems is applicable to, and cost effective for, 20 % of existing CASs. For typically large CASs in IPPC installations, the use of sophisticated master controls should be regarded as state-of-the-art.
    The highest energy savings can be achieved if the implementation of sophisticated master controls is planned in the phase of system design phase together with the initial compressor selection or in combination with major component (compressors) replacements. In these cases, attention should be paid to the selection of master and compressor controls with advanced, comprehensive and compatible communication capabilities.
    Due to the long lifetime of a CAS, this optimum scenario is not always within reach, but retrofitting an existing CAS with sophisticated master controls and – if there is no more progressive alternative – even connecting old compressors to it via floating relay contacts, can provide significant energy savings.

    由於壓縮空氣系統的生命週期很長,最佳狀態並不是天天都可達到,但在使用中壓縮空氣系統以精密主控系統改裝,如沒有更好的方法,即使與使用浮式電驛的老壓縮機連接,仍會有可觀的節能效果。(譯註: floating relay,浮球開關,水位空制開關, 此處指以壓力高低控制on/off開關)。

  • The cost effectiveness for integrating master control systems in a newly designed CAS depends on circumstances like demand profiles, cable lengths and compressor types. The resulting average energy savings is estimated to be 12 %. In the case of retrofitting, a master control system in an existing CAS, the integration of older compressors and the availability of plans gives another uncertainty, but a payback time of less than one year is typical.


  • Energy Efficiency (2009) 3.7.4