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In view of the feature of long airflow path, high wind resistance, and large area of refrigeration equipment in traditional data room, a new type of under-floor modular air conditioner and its corresponding new air conditioning solution for data room is proposed in this paper. The mathematical and physical model of the new solution for data room is established through a computational fluid simulation software and compared with two mainstream air conditioning solutions. Meanwhile, the impact of these three different air conditioning solutions on the temperature field, airflow field and energy consumption are analysed. The results show that the new type air conditioning solution for data room not only can be used to improve the distribution of temperature and airflow in the data room, but also can greatly reduce the energy consumption of the system.

This study focuses on establishing a cost-benefit evaluation model of low NOx combustion technology and the environmental benefits and economic benefits evaluation of technology operation were carried out as well. Results showed that: (1) The operation cost per unit calorific supply of the low NOx combustor with larger capacity (14 MW) boilers was 1.5-2.1 yuan/GJ, which was 22.3% to 26.2% as much as that of boilers with smaller capacity (0.7 MW). Compared with scattered boilers with smaller capacity, it is more economical to use boilers with larger capacity for centralized heating. (2) The lower the NOx emission concentration was, the greater the NOx emission reduction was. Furthermore, the lower the NOx emission benefits of low NOx combustor per unit calorific supply was, the greater the economic benefit of NOx reduction per unit calorific supply was. Based on the environmental and economic benefits analysis, the lean premixed combustor is recommended for natural gas boilers with capacity of 7 MW and below, and flue gas recirculation combustor (FGR-30) could be selected for natural gas boilers with capacity above 7 MW to achieve the NOx retrofits requirements of 30 mg/m3 or 80 mg/m3.

Greenways are an important component of the ecological network of urban green spaces and contribute to ensuring a complete and continuous ecosystem. Once a city’s greenways have been built, their future success relies heavily on visitors’ intuitive feelings and satisfaction. Therefore, it is necessary to evaluate visitor satisfaction with greenways. Using Greenway No. 1 in Shanghai’s Minhang District as an example, we in this article constructed an index system to evaluate visitor satisfaction with the greenway based on a fuzzy comprehensive evaluation method. The visitors’ demographic and behavioral characteristics and their comprehensive reviews of Greenway No. 1 were analyzed. The results showed that the gender ratio among visitors to Greenway No. 1 was relatively balanced. Most visitors were retired and elderly, and most were from nearby areas. The visitors used the greenway frequently, and the travel time for most was less than ten minutes. The overall visitor satisfaction with the greenway reached the “satisfied” level, and most indices reached the basic level of satisfaction. However, certain basic service facilities were found to be inadequate. The results provide suggestions and references for the construction of greenways in Shanghai and surrounding provinces and cities.