Study On The Outdoor Design Temperature For Summer Air-Conditioning And "Unsatisfactory Hours" Of Indoor Temperature Based On Hot Summer And Cold Winter Zone

At present,peoples living standards are constantly improving,and peoples pursuit of thermal comfort is also increasing.While pursuing higher thermal comfort,building energy consumption has further increased.Due to the huge energy consumption in our country,the focus of future development will pay more attention to the improvement of energy-saving technologies and optimizing energy consumption calculation methods.In the design of Air-conditioning systems,outdoor design calculation parameters are often determined according to a certain "non-guaranteed rate".When the outdoor temperature is transmitted indoors,due to the heat storage characteristics of the enclosure structure,a certain attenuation occurs.The actual "non-guarantee rate" in the air-conditioned room also has a certain attenuation compared to the outdoor,that is,the actual indoor thermal comfort is higher than expected.Therefore,it has the potential to study heat storage characteristics in the indoor environment has an envelope structure.Based on the outdoor meteorological data of three representative cities(Chongqing,Wuhan,Shanghai)in the hot summer and cold winter region from 1991 to 2020,this paper uses De ST software to simulate the indoor temperature of the air conditioner.In turn,it provides guidance for determining the outdoor calculation temperature of air conditioning in summer in hot summer and cold winter areas,so as to further rationalize it,reduce the power consumption of the air conditioning system to a certain extent,and achieve the purpose of energy saving.The meteorological data used in this research is the outdoor meteorological data of three representative cities(Chongqing,Wuhan,and Shanghai)in hot summer and cold winter regions from 1991 to 2020 for nearly 30 years.According to my countrys "Civil Building Heating,Ventilation and Air Conditioning Design Code"(GB50736—2012),the method for determining the outdoor calculation temperature of summer air-conditioning has constructed a set of three representative urban summer air-conditioning outdoor calculation parameters in hot summer and cold winter areas to ensure that the data is in simulation Be consistent with the calculation.Use De ST software to establish a building model of an office building in a hot summer and cold winter area,calculate the cooling load of air conditioning in summer and design the air conditioning system,and decide the equipment parameters without considering the surplus.According to the summer airconditioning period from May to October,the indoor temperature changes of airconditioned rooms in three representative cities(Chongqing,Wuhan and Shanghai)were simulated in the past 30 years.The design temperature in the office is set to 26°C.When the indoor temperature is higher than this temperature,it is regarded as "unsatisfied hours".Statistics of the indoor "average unsatisfactory hours" of three representative rooms in air-conditioned rooms from 1991 to 2020.The results showed that the indoor “average unsatisfactory hours” in the three representative cities in the hot summer and cold winter areas were all less than the “average unsatisfied 50 hours in the past year” indoors,and the “average unsatisfied hours in the past year” in the three representative cities in Wuhan was obvious.Higher than the other two cities.Analysis found that this is related to their average outdoor temperature during the air-conditioning period.Therefore,it is proposed that the outdoor “average non-guaranteed hours” can be appropriately increased according to the average temperature of each city during the air-conditioning period to meet the indoor “average unsatisfactory 50 hours” design requirement,making it more reasonable.Then,according to the above conjecture,the summer air-conditioning outdoor "average non-guaranteed hours" in the three representative cities was appropriately increased,and outdoor calculation parameters were re-selected according to the requirements of the specification,and load calculation and air-conditioning system design were carried out.Similarly,without considering the surplus,the selection of airconditioning equipment was carried out,the indoor temperature of three representative cities was simulated again,and the indoor "average unsatisfactory hours over the years" were counted.If the indoor "average unsatisfactory hours over the years" does not reach the "average unsatisfactory 50 hours over the years",increase the outdoor "average unsatisfied hours over the years" on this basis,recalculate the load calculation and simulate the indoor air-conditioning room in summer Temperature,calculate the indoor "average unsatisfactory hours" in the air-conditioned room,according to this method,repeat the simulation until the "average unsatisfactory hours over the years" in the airconditioned room in summer reaches 50 hours.In the end,it was concluded that the“average non-guaranteed hours” for outdoor air-conditioning in summer in Chongqing,Wuhan,and Shanghai was set at 66,61,and 64 hours."Satisfied hours" reached 50 hours.It is inferred from this that in order to meet the requirement of “average unsatisfactory 50 hours over the past year” in summer air-conditioned rooms,the outdoor “average unwarranted hours over the past year” can be appropriately increased.Next,the load calculation and energy consumption simulation were carried out based on the Chongqing outdoor "average not guaranteed 50 hours over the years" and indoor "average unsatisfactory 50 hours over the years".At this time,the outdoor calculated dry bulb temperature of the Chongqing summer air conditioner dropped from 37°C to 36.6°C,and the wet bulb temperature dropped from 25.7°C to 25.5°C.According to the results of energy consumption simulation,the air-conditioning system designed for the indoor "average unsatisfactory 50 hours over the past year" design reduces the energy consumption by 11.3% compared to the outdoor design for the "average unsatisfactory50 hours over the past year" design.The same method is adopted in Shanghai.The outdoor calculated dry bulb temperature of Shanghai summer air conditioner drops from35.1℃ to 34.8℃,and the wet bulb temperature drops from 26.5℃ to 25.4℃.The energy consumption of the air conditioner is reduced by 10.3%,achieving a certain energy saving effect.Finally,according to the simulation of indoor temperature in office buildings in hot summer and cold winter areas,the author proposes that in the summer air conditioning load calculation,the outdoor calculation dry bulb temperature can be reduced by0.3～0.4℃,according to the indoor setting requirement of "average unsatisfactory 50 hours over the years".At this time,the indoor environment meets the thermal comfort requirements and is more energy-efficient.