| With the increasing emphasis on energy efficiency and requirements of the thermal comfort,low-temperature radiant floor heating system is being widely used as an efficient,energy saving and comfortable heating way.The energy storage ground source heat pump-floor radiant heating system is not only using renewable energy-geothermal energy,but also employing the radiant floor heating system as the end of the air-conditioning system.Nowadays the study on the operation characteristics of the new integrated system is less,only evaluating the thermal comfort of compound system,considering the energy storage of floor and architectural noumenon to reduce the system's start time and reasonable control can achieve energy-saving and comfortable purpose.Therefore,study on heating characteristics,indoor thermal environment,and effects of system start-stop during the holidays as well as the outdoor environment on indoor environment and the optimization of regulation about energy storage ground source heat pump-floor radiant heating system is particularly important.The research object of this paper is energy storage ground source heat pump-floor radiant heating system,an office building heating system in Ji'nan is as a model.Monitoring the office building indoor temperature to analyze indoor vertical temperature distribution and comfort.With the help of TRNSYS and Airpak simulation software,study the system control strategy and indoor environmental conditions with this heating system.Through the analysis of the experiment and simulation,find the deficiency of heating status and control strategy of the system,put forward the optimization method.First,the test result shows that the vertical temperature stratification is not obvious,the basic difference is between 0.12?~0.56?,the indoor temperature is more well-distributed at vertical direction.The solar radiation has great influence on the indoor temperature,when the system has been closed for two days,the open-plan office which have more sufficient solar radiation heat gain can still remain the 18?,the north orientation office which accept weak solar radiation,can't keep 18?before 10:00 a.m.on January 4th.Suggesting that make dense the coils of weaker radiation room in actual engineering.Second,through TRNSYS and Airpak simulation,the indoor temperature is 18?~25?in the heating season,the system running stable,meet the design conditions.The indoor temperature is mainly affected by the solar radiation intensity,the outdoor temperature and the building thermal inertia.The temperature differences between every two floor are related to internal heat source and structure envelope heat dissipation.The thermal environment of the respiratory area when body maintain sitting posture range from 22.50?to 24.26?,the wind speed is below 0.4m/s,PMV and PPD are respectively-0.625~0.125 and 2.5%~10%,thermal comfort is good.Third,from December 31st to January 4th,observation and simulation show that the room temperature of the system under actual control can't reach 18?at 9:00 in January 4th.After the optimization of the pump start-stop time that both heat pump and pump open at21:00 in January 2nd at the same time,the indoor temperature reach 17.94?at 9:00 in January 4th,the indoor temperature after optimization increase 1.48?,although slightly lower than 18?,but can meet the temperature requirements in a short period of time.It is hard to ensure the indoor temperature better when outdoor temperature is low,and the temperature differences between each layer are large,so take the flow optimization control.The fifth floor which has the lowest indoor temperature is optimized by increasing flowrate 1.5 times.Meanwhile,when the outdoor temperature is less than-3?each layer's flow increase two times.After flow optimization control the indoor temperature increase by0.98?~1.49?,room temperature differences of each layer reduce.Six time distribution control mode,mode six operation hours is the longest which are 11h,while the hours of the guarantee indoor temperature K_T that the average is 14.3h,the room temperature in9:00~17:00 all satisfy the design condition.The control strategy can be used in practical engineering to achieve the purpose of energy saving and comfort.The results of this study have some guiding significance for the efficient and comfortable operation to the system. |
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