| The traditional primary air fan-coil system is not only high energy consumption but also causing mold to multiply and spread, which may affect indoor air quality, with the problems of treating heat and wet together, difficult to adapt to changes in heat and moisture and working in wet condition. As a new form of air-conditioning system, dry fan coil units and dedicated outdoor air system has the character of dealing with temperature and humidity separately, which effectively avoid the problems of traditional air-conditioning system. At present, China is vigorously promoting the green building, though dry fan coil units and dedicated outdoor air system has broad application prospects, the application of the system is few. Therefore, energy conversation, economy and thermal comfort of dry fan coil units and dedicated outdoor air system used in office buildings are studied in this paper.In the first part of this paper, firstly, it analyzes the form of water supply system and air supply system of dry fan coil units and dedicated outdoor air system. Secondly, it make a brief calculation and analysis of the air handling process of dry fan coil units and dedicated outdoor air system.In the second part of this paper, it studies the thermal comfort of dry fan coil units and dedicated outdoor air system used in office buildings. Firstly, this paper establishes the office room model by using the Airpak software, a simulation based on the Airpak software to the air flow pattern under three different types of air distribution (up-inlet and up-outlet, down-inlet and up-outlet, up-inlet and down-outlet), air supply velocity and jet angle when the office buildings adopt the Dry Fan Coil Units and Dedicated Outdoor Air System, is used to analyze the impact of different air distribution on air flow pattern through the study of indoor temperature field and velocity field in the summer case. And it draws a conclusion that, for one thing, relative to up-inlet and up-outlet and down-inlet and up-outlet, taking up-inlet and down-outlet as the ventilation mode contribute to better air distribution and thermal comfort; for another, when the air supply velocity of card type at 2 m/s, the jet angle at 30° and the air supply velocity of horizontal type at 1.5 m/s, the thermal comfort of dry fan coil units and dedicated outdoor air system is best. Secondly, when compared the two types of dry fan coil units and dedicated outdoor air system and the traditional primary air fan-coil system, the result show that the best is the card type of dry fan coil units and dedicated outdoor air system.In the third part of this paper, based on the study of thermal comfort, this paper furtherly focuses on the energy conversation and economy of dry fan coil units and dedicated outdoor air system. Firstly, calculating the hourly annual cooling and heating load by DeST software, and making a selection of main equipments of dry fan coil units and dedicated outdoor air system. Secondly, calculating and analyzing the annual energy consumption of the two air-conditioning systems by establishing the energy calculation model. And it draws a conclusion that, compared to the traditional primary air fan-coil system, the dry fan coil units and dedicated outdoor air system saves 9.9% of annual energy. Thirdly, based on the study of energy conversation, this paper calculates the early investment and annual operation cost by establishing the early investment calculation model, and evaluates economy of dry fan coil units and dedicated outdoor air system by using static and dynamic economic evaluation method. The result shows that initial investment of the dry fan coil units and dedicated outdoor air system is higher and the payback period is longer.This study provides some design suggestion and guidance for its application in domestic engineering. |
