| Radiant cooling and air-conditioning systems have attracted more and more people's attention because of their high comfort,low energy consumption,beauty and environmental protection.The radiant cooling attached jet air supply system studied in this paper is an independent temperature and humidity control system.The radiant cold plate is used to bear the indoor heat load,and the independent fresh air bears the indoor humidity load.The slotted air port is arranged on one side of the radiant cold plate,so that the outflow air is attached to the surface of the radiant cold plate,which isolates the indoor high-temperature and high-humidity air from the surface of the radiant cold plate and enhances the convective heat transfer on the surface of the cold plate.It also reduces the risk of condensation on the surface of the cold plate.The radiant cooling air conditioner studied in this article mainly includes three installation forms: the radiant cold plate is installed on the indoor ceiling and the wall.And when the radiant cold plate is installed on the wall,there is a deflector on the lower edge.When combined with wall-attached-jet air supply system,studied the difference in indoor thermal and humid environment of different systems.It mainly analyzes the distribution of indoor velocity field,temperature field and relative humidity field,and compares the differences of different system forms in indoor cooling,dehumidification efficiency and comfort level.And studied the indoor movement and distribution of aerosol particles emitted from the human mouth under different airflow organization.When different systems are adopted,the velocity distribution in the height direction of the space is basically the same,and there is only a difference in velocity at a height of 0.1m.At a height of 0.1?3m,the velocity distribution is lower than 0.1m/s,and there will be no blowing feeling;The wall radiant cooling system has a better heat exchange effect with the human body,and the cooling effect is better than that of the ceiling radiant cooling system,and the temperature difference is about 0.2?;The wall-attached-jet air supply system has a good adhesion effect on the surface of the cold plate,and no condensation will occur.The indoor average relative humidity value radiated by the ceiling decreases to 50.06% after the system runs for 4000 s,which is the closest to 50% of the design state,and its dehumidification effect is the best;The dehumidification efficiency and the average indoor relative humidity value of the wall radiation with the deflector are better than the radiation effect of the wall without the deflector,and the relative humidity balance value of the two differs by about 0.63%.At a height of 0.1?2.4m,the PMV value of the three systems is not less than-0.1 and not more than 0.4,and the thermal sensation is moderate,which meets the requirements of human comfort,and only differs at different heights.At a height of 0.1m,the thermal comfort of the wall radiation is the best;At a height of 0.7m,the wall with a deflector has the best radiation;At a height of 1.1?2.4m,the PMV value basically does not change,only differs in different forms.The PMV value of the ceiling radiant cooling system is maintained between 0.35 and 0.4,and the wall radiant cooling and wall radiant cooling with deflector is maintained between 0.3 and 0.35.Different air distributions lead to different diffusion modes of indoor particles.Large-sized particles sink under the influence of gravity,and small-sized particles diffuse.Within 0?300s,97.2%?98.5% of the particles were captured by the wall,and only 0?2% of the particles diffused from the releasing source Man 1 to Man 2,which was 1.8m away,and only a small part of fine particle size was suspended in the air.When the wall is attached to the air supply,the indoor aerosol particle concentration drops the fastest,and the aerosol particle concentration after 300 s is also the lowest.In the wall-attached-jet air supply system with deflector,the indoor aerosol particle concentration was higher than that of other forms at the same time in 0?300s. |
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