Optimization design and performance analysis of a heat recovery and storage system for sports stadiums

Sports stadiums, as high-energy-consuming public buildings, face challenges such as high energy consumption and low waste heat utilization. This paper constructs an optimization model for a heat recovery and storage system coupled with the building?s thermal environment. Through key component selection, layout optimization, and multi-operating-condition simulation analysis, the system?s energy-saving performance is improved. A 1:1 stadium model was constructed using the TRNSYS and FLUENT co-simulation platform. Verification results show that the deviation between simulated and measured energy consumption is ?5%, and the temperature deviation is ?1.2?C. Simulation data demonstrates that the system?s heat recovery efficiency reaches 75.4%-78.6% under normal operating conditions, increasing to 79.3%-81.2% under event conditions and remaining above 72.5% under extreme conditions. Daily fluctuations in energy storage are controlled within 5.8%-7.6% under normal operating conditions and approach 8% under extreme conditions. The heat pump COP reaches 4.5 at 25?C, but significantly decreases to 2.3 at -5?C. This efficiency exceeds traditional rotary heat exchangers (?60%) by 15%-20%, demonstrating significant improvement. The research achieved the goals of heat recovery efficiency ?75% and energy storage fluctuation ?8%, providing support for upgrading energy-saving technologies in sports stadiums.