Multi-parameter Coupling Optimization Research Of Forced Convection Radiator For Building Low Temperature Heating

With the continuous development of China’s economy and the continuous improvement of people’s living standards in recent years,the demand for building winter heating is increasing day by day.At present,central heating systems are widely used in northern cities and towns,using cogeneration or centralized coal and gas boilers as heat sources.The resulting carbon emissions are about 450 million tons,accounting for 20% of China’s total carbon emissions from building operations.With the rapid improvement of China’s urbanization level,urban heating area will further increase,and the carbon emission of central heating system will become more prominent.Therefore,"energy saving and consumption reduction" of central heating system has become a key topic to promote green and low-carbon development in the construction field and achieve the goal of "carbon peak and carbon neutrality" in the construction industry.Low temperature heating technology can reduce the temperature of supply and return water of primary and secondary heating networks,thus reducing the heat loss of the network,and improving the economy of the heating system on the premise of ensuring the thermal comfort of the room.The current low temperature heating technology mostly uses radiant floor as the interior terminal.However,because the construction of floor heating involves concealed works,and the construction cycle is long,the process is many,and the cost is high,it is not suitable for the energy-saving transformation of existing buildings.In this paper,the thermal environment and thermal comfort of a room with radiator used for low temperature heating are studied by means of measurement and numerical simulation,and the feasibility of using forced convection radiator to realize low temperature heating is further analyzed,and its application mode is optimized.The specific research contents of this paper are as follows:First of all,the thermal environment parameters in an office in the cold area were measured when the steel plate radiator was used to realize low temperature heating.On this basis,the distribution and variation rules of indoor temperature and other parameters were analyzed,and the indoor thermal comfort level was quantified based on PMV-PPD.The results show that the radiator low temperature heating system can basically meet the requirements of personnel comfort.Second,in order to further analyze the measured distribution of temperature in the room and to predict the velocity field inside the room,the room air flow field in the CFD numerical simulation,and the reliability of the simulation results verified by comparing the measured data,the results show that the work area meet the requirement of personnel,and the air velocity and the temperature distribution in the ideal of the room,The system can be used as a heating method for continuous room heating.Finally,a low-temperature hot water radiator based on forced convection is proposed,and the indoor thermal environment created by it is simulated by CFD.On this basis,the air supply velocity at different baffle angles of 0°,45° and 90° is optimized,and the surface temperature of the radiator corresponding to the optimized wind speed is obtained.The above results can provide important reference for the design and application of forced convection cryogenic radiator.