| Radiation air-conditioning system created conditions for good indoor thermal comfort,dedicated outdoor air system solved the air quality problems,compared with the traditional convection air-conditioning system,the combination of the two subsystem not only meet the needs of the human thermal comfort,but also has great energy-saving potential.It's important to select a reasonable thermal comfort evaluation model in the application of propulsion radiation-coupled air-conditioning system.Different from developed countries,Chinese thermal comfort standard does not have clear provisions on the thermal comfort evaluation model of asymmetric radiation environment,therefore,it is particularly important to search the thermal comfort evaluation model applicable to China.In this paper,the indoor environmental parameters of radiant cooling coupled dedicated outdoor air system air-conditioning in summer were tested in a residential building in Changsha area.Meanwhile,the actual thermal sensation of indoor subjects was evaluated by subjective questionnaire survey,then given the human body thermal comfort sensation,the residents neutral temperature and acceptable temperature range.Based on above that through the analysis of the differences of the TSV model,the PMV model and the APMV model respectively,the actual thermal sensation was most sensitive to somatosensory temperature and the acceptable temperature range was significantly narrower than the predicted range.Radiant cooling environment and the outside of the window cause asymmetric radiation characteristics were analyzed,starting from the adaptation coefficient correction of APMV model and the asymmetric radiation characteristics of the room itself,this paper proposed radiation coupling residential air conditioning APMV correction model and PMV correction model based on asymmetric radiation problem suitable for radiation-coupled air-conditioned residences in Changsha area summer,which provide the basis and method for the scientific evaluation of the thermal comfort of the radiation-coupled air-conditioning system and the optimization design and operation of the system.This conclusion will provide a reference for the establishment of thermal comfort evaluation model of radiation-asymmetric environment in China's relevant standards.In addition,radiation asymmetric temperature,indoor air flow distribution,vertical temperature difference and ground temperature in the radiation-coupled air-conditioning system were simulated and compared with the above test results,selecting different grid density,radiation heat transfer models and turbulence models in the process of indoor thermal comfort CFD simulation,the optimization and comparative study are carried out.The results show that:(1)When the density grid is 743215,the standard error is 0.0154 and the relative error is only 12.6%.It can be found that the wind speed simulation results of the medium-density grid have smaller deviation,higher stability,and the simulation results are more consistent with the actual situation.(2)Comparing the simulation results of S2 S model with DO model,it can be found that the relative error between the simulation value of wind speed of DO model and the actual wind speed is 24%,and the maximum deviation between the temperature simulation value at the elevation measurement point and the measured value is 0.5k.Compared with S2 S model,the simulation result of DO model is more close to the test result.(3)The influence of different turbulence models on thermal comfort is investigated.It was found that the standard deviation of the RNG k-model is 0.0120,the stability is good and the relative error to the actual wind speed is only 14.0%.Meanwhile,the effective draught temperature EDT was calculated,then the indoor air characteristic distribution index ADPI was 81.48%,meeting the thermal comfort conditions without drought sensation.Above that the simulated wind speed of the RNG k-? model has a small fluctuation,a high stability and a better fit with the actual value.This conclusion will provide a reference for the selection of simulation parameters and models suitable for the radiation asymmetric environment in the following studies... |
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