The Development And Engineering Application Research Of Heat-adjusting Device At The Heat Inlet

The Central Heating System is a dynamically changing process in practical operation.During the heating period,due to changes in the climate,the outdoor temperature changes all t-he time.Obviously,from morning to noon,the outdoor temperature gradually rises,it reaches a peak when a center time in the noon.And from the afternoon till evening,the outdoor temperature gradually decreases.So,the heat load of the building continues to change and follow the outdoor temperature throughout the day.However,in heating industry at present,it usually lacks distal instrument at the end of the heating network.So the heat network operation status is only known through the heat exchange station,and it is difficult to ensure that the heat supply of each building is matched with the current heat load,only by intermittent adjustment of the heat exchange station based on experience,which is prone to “near-end user overheating,remote user over-cooling” phenomenon.In practical operation,it may often increase the heat supply of the secondary heating network,because the indoor temperature of remote user cannot meet the demand,which only leads to a more serious phenomenon of the overheating in some users.Therefore,it is very important for the whole heating system to perform reasonable operation adjustments.Under the premise of guaranteeing the user's thermal comfort,the energy consumption for heating is reduced.In order to adapt to the regulation of the indoor heating system and ensure the safe and stable operation of the system,it is necessary to realize the automatic control of the heating system.The heat-adjusting device at the heat inlet proposed in this paper is based on the energybalance method as the control principle,and adopts the PID control algorithm to regulate the heat supply through the electric regulating valve.At present,it has realized the computer automatic monitoring and autonomous real-time adjustment function.It can not only monitor the user-side operating parameters in practical operation,but also automatically adjust the circulating flow to achieve the on-demand distribution of the entire heat network flow.It can also ensure that the average indoor building temperature is stable at a certain set temperature while guaranteeing the heat supply to supplying the load of the building.In this paper,the feasibility of the device is verified by the theoretical analysis combined with the practical application.Firstly,the functional positioning of the Heat-adjusting Device was determined through the previous investigations and many literatures;then the control principle and implementation of hardware and software were described in detail.In designing the device,the process of implementing the process system and the control program were highlighted.Finally,for a practical engineering application,the control process,control effects,and energy-saving effects of the heating system were discussed.And four different time-division heating conditions were tested against the characteristics of the office buildings,comparing and analyzing its control effect and energy-saving effect from the indoor average temperature and heating quantity.