CO2 in geventileerde bewaarplaatsen

Dit document beschrijft een eenvoudig model voor voorspelling van het verloop van de CO2 concentratie in bewaarplaatsen. Het model is tevens geïmplementeerd in een gebruiksvriendelijk excel-programma. Doel van dit programma is om in het ontwerp van bewaarplaatsen beter gefundeerde beslissingen te kunnen nemen over te installeren luchtverversingscapaciteit. Ter verificatie van belangrijke modelparameters is de ademhalingsactiviteit van een vijftal product/opslagtemperatuur-combinaties bepaald

Quest II: reduction of co2 emissions of reefer containers

This paper reports on the QuestTM II (QUality and Energy in Storage and Transport) development project run by Wageningen UR Food & Biobased Research, Maersk Line and Carrier Transicold. The aim of the Quest II development project was to improve the control of refrigerated marine container (reefer) units with the objective of maximizing energy efficiency in chilled mode operation without impairing produce quality. Lab testing research on produce quality revealed the limits by which deviations from the optimal transport temperatures are acceptable. Those limits were used in the design of the Quest II algorithm. Quest II control reduces energy consumption in chilled mode operation by 65% compared to non-Quest control. The savings are achieved by replacing continuous throttled compressor operation by an ON/OFF compressor control, and by automatically optimizing internal air circulation with heat load instead of continuous operation at maximum internal air circulation. Extensive produce quality research and hundreds of field trials reveal no adverse effect on produce quality while using the Quest II algorithm

Quest II produce quality research overview

The Quest II control algorithm (patent pending), developed by Wageningen UR Food & Biobased Research together with Maersk Line and Carrier Transicold, reduces the energy consumption of reefer containers by approx. 65% without impairing produce quality

Modelling and control of an N-removing activated sludge process

In this paper an approach to obtain a control strategy for optimal N-removal in alternatingly aerated, continuously mixed, continuously fed activated sludge processes (ASP's) using adaptive Receding Horizon Optimal Control (RHOC) is presented. This control strategy is successfully tested both in simulation and pilot plant experiments. The RHOC approach offers an excellent opportunity to link the higher level of plant economy and the lower level of plant control by expressing the plant economy in the RHOC's cost criterion, including constraints on in- and outputs. Essential for the performance of RHOC controllers is the availability of accurate predictions of near-future NH4 and NOx concentrations. A recursive estimator for the model parameters of a grey-box model identified from experimental data is designed to keep the model close to the real process behaviou