Experimental set-up and comparison of a thermal load model for livestock barns

Intensive livestock farming stands out as an energy-demanding sector within agriculture. Despite this, precise hourly temporal information regarding on-farm energy use both in terms of quantity and fuel source is not available. This information is needed for evaluating and comparing scenarios using renewable technologies like heat pumps, photovoltaics, small wind turbines, etc. As such, a modelling approach tailored to one pig farm in Belgium, was developed in 2022 to derive hourly heating and cooling loads. To calculate these loads, the model assumes a quasi-steady state energy balance, taking into account occupation numbers (including their respective age and environmental needs), and outside temperature and relative humidity. The model predicts a total heat load of 212 MWh per year, an underestimation of 4 % compared to the average use of the barn (220 MWh). In this work, the same model is tested against physical measurements on the pig farm, using a transportable experimental set-up by means of an ultrasonic flow rate meter and temperature sensors at the inlet and outlet pipes of the heating circuit. These measurements were performed during three non-consecutive weeks: one in spring 2021, summer 2023, and winter 2024. Respectively for each period, the thermal model overestimates the measured load by 80 %, 10 % and 3 %, but with local outliers reaching up to 700 %. In the next steps, the thermal load model will be improved upon and expanded to include electrical loads as well. Eventually, the model can be applied to other farms in Belgium and validated with the transportable set-up.