Supermarket refrigeration systems for demand response in smart grids
Article 1 explores the temperature control system in depth, concluding that the majority (80.5 %) of return air temperature sensors in RDCs were located in an area where a thermal gradient interfere with the perceived temperature, i.e. the temperature readings falsely indicated a higher return air temperature than the actual mean temperature of the passing air. The issue is analysed in detail and mitigated through a strategic re-positioning of the affected temperature sensors.
Article 2 presents a computationally efficient yet accurate dynamic hygro-thermal model of an RDC with the capability to include effects of door openings. Thus, the model contributes to enabling demand response by supermarkets as it could provide the forecasts of the necessary temperature constraints, limiting the duration for which the supermarket could attend to a demand response request.
Article 3 presents a field study where wireless gyroscopes were attached to the RDC doors in an operational supermarket to record the speed, duration, angle and frequency that the doors are operated at. Novel insights in significant differences in behaviour between medium and low temperature RDCs could be concluded.
Article 4 presents a method for the thermal characterisation of RDCs based on an adaption of the Co-Heating methodology. The method evaluates infiltration rates within the 10 % limit compared with the condensate collection method. In addition, data on thermal performance, such as the heat transfer coefficient for the envelope and its thermal inertia, can be measured in a systematic way.
The thesis together with the four appended articles presents a suite for the evaluation of temperature development in refrigerated display cabinets in operational supermarkets, which represents the main constrain for the demand response capacity.
Refrigerated Display Cabinet
Chalmers, Arkitektur och samhällsbyggnadsteknik, Byggnadsteknologi
Analysis of door openings of refrigerated display cabinets in an operational supermarket
Journal of Building Engineering,; Vol. 26(2019)
Artikel i vetenskaplig tidskrift
Supermarkets as thermal buffers for renewable electricity grids
Climate-KIC, 2013-10-01 -- 2018-09-30.
Innovation och entreprenörskap
Building Futures (2010-2018)
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4873
Chalmers tekniska högskola
Opponent: Prof. Savvas Tassou, Brunel University London, Storbritanien