Research On Air Carrying Energy Radiant Air-conditioning System For Animal Welfare In Laboratory Animal Room

With the progress of society and economic development,laboratory ani mal science has become an important subject in the study of biomedicine and various disciplines of nature.Due to the high environmental requirements of laboratory animals,most of laboratory animal rooms use new air systems and the continuous operation time is long,which results in the huge energy consumption.As a continuation of human welfare,animal welfare has become so hot a topic that people pay more and more attention to it.An laboratory animal room of a biological company is taken to be the research object in this study to establish the model of air carrying energy radiant air-conditioning system(ACERS)and the model of traditional air-conditioning system respectively.By the means of computational fluid dynamics(CFD),the temperature,humidity,wind speed and pollutant distribution of the laboratory animal room under two air-conditioning systems are obtained to analyze the feasibility and superiority of the application of ACERS in the laboratory room,combining with the concept of animal welfare.On this basis,the number of air changes is changed to observe the influence on the distribution of indoor environmental parameters under two air-conditioning systems.In addition,combined with the current energy consumption background,the advantages and disadvantages of several laboratory animal room energy-saving methods are discussed.A new control strategy of dual-condition air-conditioning purification unit is proposed to save energy on the basis of ensuring the pressure requirements of laboratory animal room.The results of this study show that temperature distribution in the laboratory animal room is uniform under ACERS when the working conditions is in summer and the number of air changes is 10 times an hour.The vertical temperature difference between the height of 2.1m and 1.1m is 0.65°C.However,the temperature gradient of the traditional system is 3.7°C under the same conditions,so ACERS can create an indoor environment with a low temperature gradient and all animals in the laboratory animal room can be taken into account.The relative humidity in the room is small,and the temperature under the orifice plate is far below the condensation temperature so condensation does not occur.The indoor airflow velocity under ACERS is small which is no more than 0.15m/s and is no more than 0.1m/s near the animal cage.The airflow speed under traditional system is relatively larger and reaches to 0.2m/s in some areas,but it still meets the requirements of the national standard.The concentration of indoor pollutants under both systems is far lower than 14mg/m~3required by the national standard,but it is necessary to strengthen monitoring to prevent the accumulation of pollutants and the spread of odor.When the number of air exchanges increases,the indoor environmental parameters under ACERS change little,while the temperature gradient under the traditional system decreases and the airflow speed increases.The speed may exceed 0.2 m/s in some areas.It should be noted that there is a limit air exchange frequency under both systems.At this time,the increase of air change frequency has little influence on the elimination of indoor pollutants.Therefore,energy saving can be achieved by reducing the number of air changes.The ACERS not only can create an indoor environment with low temperature gradient and low air speed,but also has the characteristics of low energy consumption,which can bring huge energy-saving benefits.In this paper,ACERS is recommended to be applied to the laboratory animal room to conduct research and analysis on the environmental facilities of laboratory animals facing“three lows”(low energy consumption,low air speed and low temperature gradient).On the basis of satisfying the animal welfare,it provides new ideas and new ways to seek energy-saving methods for laboratory animal room.