Due to the increasing costs associated with electric energy consumption major concern has lately been paid to ensure optimal refrigeration technique operation in shopping centers. An integral solution is accomplished by connecting numerous shopping centers into a completed whole controlled by a central system where optimization algorithms are run based on the defined strategies. This thesis defines and evaluates strategies for optimization of electric energy consumption costs of refrigeration technique. The strategies are based on the analysis of electric energy consumption regarding the measurements performed and obtained from existing shopping centers. Comparison between flat rate and time-based pricing is included.
D.10 Educational activitiesCOBISS.SI-ID: 10871380
The main aim of the thesis was to develop a hybrid model of the refrigeration system. The dynamical model of the display case was set-up in the AnyLogic modelling environment. The model was additionally extended with the crucial discrete events, like: door openings, product refilling and periodical defrosting events. In the thesis a detailed overview of the modelling basics was given, where dynamical modelling was only quickly overviewed and the main focus was given to the discrete event modelling. The development of the hybrid display case model within AnyLogic was presented in detail, where each modelling step was elaborated. The presented optimisation analysis was focused on the evaluation of how the door opening frequencies, food mass and defrosting schedules impact on the operating energy costs and the quality of the stored food.
D.10 Educational activitiesCOBISS.SI-ID: 29358887
The flexible prices of electrical energy are enabling new strategies for optimising the energy costs. The paper introduces two different energy cost optimisation approaches for refrigeration systems in shopping centres. The first represented approach is adjusting the energy consumption profile while changing the temperature references of individual refrigeration cabinets, and the other minimises the number of defrosts as defrosts are triggered only on demand. In order to quantify the effects of such approaches, the article introduces the physical model which describes the temperature and energy dynamics of the refrigeration cabinets and frozen food. Model parameters are identified on the basis of the data measured in the selected shopping centre.
B.06 OtherCOBISS.SI-ID: 28529703
Implementation of the algorithms, for optimizing the power consumption and costs of refrigeration systems, is usually severely restricted, due to the lack of appropriate platforms that would centralize optimisation actions. Ideally, platform should be able to integrate several refrigeration systems into one system and should be realized on the cloud technologies. Refrigerators in shopping centres are connected to a controller which is connected to local area network. Consequently, a communication between refrigerators and cloud based optimization system is needed. This paper focuses on possible implementations of a refrigeration system agent and more specifically on our implementation of the agent that enables the missing communication link between the refrigeration system and cloud platform.
B.03 Paper at an international scientific conferenceCOBISS.SI-ID: 11515732