Projects and Objectives

A client of ours, specializing in the construction and restoration of trains, expressed the need to optimize the management of domestic hot water during the modernization of trains intended for luxury tourism. The goal was to ensure a continuous water supply between two refueling stops, accurately estimating the required storage volume. Additionally, the client sought to predict the flow rate and water pressure behavior at the points of use to ensure that the distribution would always meet the needs of each individual outlet. This included a detailed evaluation of the efficiency of the water heating and distribution system, taking into account thermal losses along the piping system and external climatic conditions.

Approach to Analysis

Thanks to BSIM’s expertise in 0D/1D fluid dynamics simulation, it was possible to develop a simulation model of the entire water system of the carriage, including the refilling and emergency supply connections with adjacent carriages. The study considered a range of external ambient temperatures, from extreme positive values (+45 °C) to extreme negative values (-50 °C), assessing the system’s efficiency and adequacy under each condition.

Sketch Amesim

The client provided the vehicle’s CAD model and the technical diagrams of the water system, including the characteristic data of individual components (valves, faucets, pumps, thermal systems, insulating systems, etc.). BSIM’s engineers proceeded to create a Digital Twin using the Simcenter Amesim application and subsequently extracted the results, evaluating the best configurations.

The water reserves at ambient temperature, stored in the primary and secondary tanks, exhibited different behaviors depending on the installed faucets and the water management strategies adopted on board the train. Using Simcenter Amesim, it was possible to simulate the performance of various types of installable faucets, allowing the identification of the optimal configuration to ensure maximum comfort and water savings. This enabled the planning of an efficient management strategy for potable water reserves, tailored to cover the distance between two predetermined refueling points.

Furthermore, the selection of valves, faucets, and pumps influenced the pressure conditions for each point of use. The simulation enabled the determination of the ideal configuration to ensure an adequate flow of domestic hot water to all the train’s suites.

The centrifugal pumps used to supply the outlets exhibited cavitation issues in certain configurations. Therefore, the optimal combination was identified to prevent this issue, even under the most critical conditions.

A large-scale system like the one implemented on the train under consideration requires an appropriately designed domestic hot water (DHW) management system. BSIM simulated the production and consumption of DHW under standard and extreme conditions using thermal heating systems. During the numerical simulation phase, a severe DHW supply issue was identified early on when a high number of outlets in various suites were used simultaneously.

BSIM then provided the client with the necessary requirements to ensure optimal supply and management of domestic hot water for each point of use. This allowed for the identification of the most suitable thermal equipment to meet the system’s needs, ensuring both efficiency and continuity of service.

Conclusion

The results were shared with the client step by step throughout the entire development process, thereby accelerating the design and prototyping phases and preventing potential water and thermal management issues in the later stages of the project.