Evaluation study on wheat straw storage schemes based on BWM–TOPSIS method

Due to its own physical properties and the demand characteristics of energy enterprises, straw is prone to the issue of excessive storage during the burning utilization process, thereby reducing the efficiency of energy conversion. This study explores the evolution of physicochemical characteristics of straw under long-term storage and constructs an evaluation index system with moisture content and other key indicators. On this basis, the Best–Worst Method (BWM) coupled with the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is adopted to conduct a comprehensive assessment of different bundled straw storage strategies. The experimental results show that the straw stored in an open environment is more susceptible to external climate conditions interference than that in a closed environment. Its moisture content, ash content, volatile matter content, fixed carbon content, and higher calorific value all show significant fluctuation changes. The weight calculation results show that the higher heating value is the key indicator determining the efficiency of energy conversion (with a weight coefficient of 0.46409). Through the TOPSIS method, the ranking of the superiority and inferiority of each storage scheme is as follows: square bales in a closed environment > square bales in an open environment > round bales in a closed environment > round bales in an open environment. Among them, the C value of the storage scheme with the best storage effect, the closed environment bundled straw, is 0.848, while the C value of the storage scheme with the worst effect, the open environment round-bundled straw, is only 0.155, with a significant gap. This research can provide a scientific basis for straw middlemen and farmers to optimize storage schemes and improve energy conversion efficiency.