Usability of a virtual sensor in a domestic heat pump application
As domestic heat pump systems become increasingly important to achieve residential energy efficiency, the need in cost-effective solutions for optimizing system performance is becoming more significant. Digital twin technology is a promising approach to optimize energy efficiency and performance of these systems. Calculated values can be used for control or diagnostic applications. These values can potentially be of better quality than measured data from a simple hardware sensor or even provide data which cannot be measured directly cost-effectively, thus replacing a hardware sensor. A digital twin of the heat pump was developed and realized as a continuously running simulation model with a focus on utilizing the compressor outlet temperature as a virtual sensor use case. This parameter was selected due to its critical role in achieving optimal control of the heat pump system. The challenge of tailoring the model to individual heat pump systems, which vary from nominal systems due to manufacturing tolerances, is addressed. The workflow of modeling is presented, emphasizing the balance between representing relevant physical behavior and minimizing computational effort. By optimizing this balance, accurate and efficient real-time data can be provided. Furthermore, the process of tuning the digital twin to each appliance, which may differ from the nominal system, is described. Measurements are used to evaluate the quality of the virtual sensor in comparison to a hardware sensor used in domestic heat pump appliances. The possibility of replacing the hardware sensor with the virtual sensor is discussed.