The Study On The Fan-coil Unit With Fresh Air System On Dry Condition

The fresh air system remove 100% the space latent loads and partial sensibleloads, and the terminal equipment is required to remove only the sensible loads thatremain after the dry ventilation air has been introduced into the conditioned space,this system is called Fan-coil Units with Fresh Air System on Dry-coil Condition.People have a prejudice against the current air condition method after SARS epidemic.So, many engineers do some researches on how to give people a safe indoorenvironment. One of them is the dry-coil condition system. Many engineers havereconsidered its profits and defects. This thesis does some research on the main partsof dry-coil condition system.The dry-coil condition system has some similar facts to DOAS system which is apopular topic in HVAC researchers. The realistic methods to change an originalwet-coil condition to the dry-coil condition are to adjust the operating mode of thechiller, change the different controlling parameters of the system and to develop newfresh air handling unit. From here, numerous problems have produced, for example: Isthe low consume of dry-coil condition system can make up the reform reconstructionexpenses? How about the proportion of the loads'allocation that the fan coil unit andout-door air each bears? For the sake of dry-coil condition, could the loads of eachsystem satisfy the needs? If the fan-coil units only bear the sensible loads, how can wedeterminate the parameters of the fresh air system? Is the old wind pipe system stillsuitable? All the questions above affect the realization of the new system.Aiming at the problem above, this thesis analyzes the fresh air fan-coil system ofthe office building. The analyses and calculations include the following points: theparameters of the whole system, the energy saving and the economic analysis, therequirement to the fresh air handling unit, etc. These researches are especiallyconsidered about the renovation project. Through the analyses above, we think it is akey to develop a new fresh air handling unit. This thesis has proposed a kind of freshair handling unit, calculate its main parts, and design it. At the same time, this thesisinvestigates a new type of metal filter material on its filter efficiency. Measured,cultivated and counted the air before and behind the filter material separately by usingAndersen sampler, LWC-1 sampler and particle counter. Analyze the relationship ofthe filter efficiency on bacteria, the filter efficiency and the resistance pressure. Theresults show that this type of filter material has a high filter efficiency and it has avirtue that can be cleaned, which make us can reasonably believe that it will has abooming prospect when applied in fresh air system of center air conditioning system.