新旧国标电动自行车燃烧对比差几秒？实景燃烧实验揭晓答案

Core Viewpoint - The transition period for the new mandatory national standard for electric bicycles (GB 17761—2024) has officially ended, leading to a complete ban on the sale of old standard electric bicycles, with significant improvements in fire safety performance under the new standard [1][2]. Group 1: Fire Safety Performance Comparison - The old standard electric bicycles had a high proportion of plastic components and low flame-retardant ratings, releasing a large amount of toxic smoke during fires [3]. - The new standard electric bicycles have optimized fire safety and flame-retardant technical indicators, limiting the total mass of plastic components to no more than 5.5% of the vehicle's total mass [3]. - In a fire scenario, the old standard electric bicycle took 180 seconds to completely cover the building with smoke, while the new standard electric bicycle delayed this by 48 seconds, covering the building in 80 seconds [2][5]. Group 2: Experimental Data Insights - The peak concentration of carbon monoxide for the old standard was 1205.1 ppm after 16 seconds, while the new standard showed a significant reduction in concentration [5]. - Smoke peak values were 7019 ppm for the old standard at 49 seconds, compared to 2519 ppm for the new standard at 52 seconds, indicating a 64% reduction in smoke concentration [5]. - The new standard electric bicycle's high-temperature area covered only the first three floors of the building, compared to the first four floors for the old standard, demonstrating a reduction in fire spread [2][5]. Group 3: Market Readiness and Consumer Concerns - Experts clarified that the new standard does not require electric bicycles to have metal seats; foam seats that meet fire safety requirements are sufficient [6]. - Concerns regarding the "speed cut-off" feature of the new standard, which stops power output when speeds exceed 25 km/h, were addressed, confirming it will not cause sudden braking during normal operation [8]. - As of now, over 600 models from more than 30 mainstream brands have passed 3C certification, with production capacity increasing to meet consumer demand [8].