Regarding the problem of indoor ventilation, in fact, the indoor ventilation aspect is similar to the ventilation and heat dissipation problem of the data center we talked about before, but this time a new module will be introduced - human comfort problem, there is an HVAC module in the flow simulation is specially used to study human comfort, which can ** people's general thermal sensation and discomfort and air quality assessment in a thermal environment.
Human comfort generally includes average radiant temperature (MRT), operating temperature, average thermal sensory index (PMV), percentage of dissatisfaction (PPD), ventilation volume (DR), tensile temperature, air diffusion performance index (ADPI), pollutant removal efficiency (CRE), local air quality index (LAQI), and flow angle.
Next, we will introduce a model of an isolation ward in a hospital to analyze human comfort.
Now with the layout of the isolation ward to analyze, in this model we need to determine what the heat sources are, this model includes, televisions, medical equipment, chandeliers, and of course, may also consider the heat exchange of people. Regarding ventilation, there is an air inlet and an air outlet, as well as a toilet also has an air outlet;The patient's body temperature can be set to 39 degrees Celsius and the caregiver's body temperature is a normal 36 degrees Celsius. Here we need to consider not only the ambient ventilation, but also the exhaled air of the human body.
After determining the above conditions, you can enter the software setting interface, and you can set the internal flow field in the wizard interface, and remember to change Kelvin to Celsius. Gravity is set to the direction of gravity in the negative direction of the y-axis, i.e. -98m/s^2。
Set the default fluid to air, and then set an additional fluid as the air exhaled by the human body as a pollutant. After setting the above prerequisites, it can be set according to the above-mentioned heating source heating power and temperature, inlet and outlet wind speed, and ambient atmospheric pressure.
After adding the grid settings, we can start running, and when we are done, we will see the results.
After post-processing, the cross-sectional contour of LAQI (Fig. 1) was seen, and the higher the value of LAQI index, the better ventilation effect of the place, and the ventilation system had the best effect on the removal of indoor pollutants. Here and the most obvious air inlet is the best effect directly below the air inlet, and the effect on the right side of the diagram is less effective.
Figure 1: In Figure 2, PMV is the average thermal sensation indicator, and we can tell that the overall feeling of warmth around the human body can be judged based on the isogram and the following indicators** (Figure 3).
Figure 2
Other parameters related to human comfort can be seen in Figures 3 to 4 finally.
Figure 4