Numerical simulation and analysis of smoke detector response to varying fire source locations in brick-timber heritage buildings: a case study of Kashgar old city

Introduction Brick-timber heritage buildings, characterized by masonry walls and extensive use of wood (e.g., poplar, pine) in structural elements, possess high historical and cultural value, yet this material composition makes them susceptible to fire hazards. Smoke detectors are critical devices for early fire warning, and their response characteristics in brick-timber ancient building fires are of paramount importance. Methods This study employs an integrated numerical simulation approach, utilizing the Pyrosim fire simulation software to model different fire scenarios in brick-timber ancient buildings, aiming to investigate the impact of fires on the response characteristics of smoke detectors. The study analyzes the smoke generation rate, temperature, and spread patterns from different ignition points—such as central fires, edge fires, and corner fires—within the complex spaces of ancient buildings, as well as the influence of these factors on the response time and sensitivity of smoke detectors. Results Simulation experiments indicate that when the fire source is located at the center of a room, the smoke detector triggers at 59.5 s; when the fire source is situated in a corner area of the room, the smoke detector triggers at 22.4 s; and when the fire source is positioned in the central hall area of the room, the smoke alarm triggers at 16 s. The findings reveal the variation patterns of smoke detector response characteristics in fire scenarios within brick-timber ancient buildings. Discussion This paper provides theoretical foundations and data support for optimizing the selection and layout of smoke detectors in ancient buildings, enhancing the reliability of fire warning systems, and improving the fire prevention and control capabilities of brick-timber ancient structures, thereby better preserving precious historical and cultural heritage.