Research On Regulation Methods Of Heating Network Balance Of Panjin Eastern Thermal Power Plant

Central heating as the most important heating mode in the urban areas in Northern China,is becoming more and more important in production and living,and gradually becoming another lifeline after water,electricity and gas of the city.With the constant expansion of the scale of central heating,the degree of difficulty and complexity of the regulation of heating system also increased,which is undeniable,compared with the developed countries,there is large gap in the standard of central heating in China,centrally embodied as large energy consumptions,low management level,inadequate regulation and control capacity,and etc.Especially there are lots of urban population,large thermal network coverage area,complex pipeline,and hydraulic imbalance and other problems often happen,which affected the indoor comfort of tenants,also increased the operating costs of heating supply enterprises.The thesis analyzed the concept,the classification and the reason of hydraulic imbalance in the system.Several methods of regulating hydraulic balance are summarized,among which,the hydraulic balancing device is widely used,and the structure,the working principle,the flow characteristic and others of several common hydraulic balancing devices are introduced.For the problems existing in the operation and regulation of urban central heating system in China,the pipe network model is established by using Flowmaster.Taken the heating networks of Panjin Eastern Thermal Power Plant as the research object,the field survey was carried out,the operation data of some heating networks were collected,and the field measurement of heating network parameter and household survey were carried out in two residential communities.Modeling and simulation analysis for the pipeline network were carried out by using Flowmaster,taking the general heating network as an example,the modeling characteristic and the hydraulic conditions of the heating network of the software were explained.By changing the corresponding parameters of each unit of the pipeline,the model of the simple pipeline network is gradually complicated.By changing the flow rate of the circulating pump in the heating network by the pump frequency converter,the hydraulic conditions of each section,and the actual impact on various types of pipeline networks by the analog adjustments were calculated.The data of 33 heat exchange stations on the "middle line" of Panjin Eastern Thermal Power Plant were selected,analyzed and calculated,and the corresponding opening value of balance valve and theoretical balance flow of the heating network were obtained.The balance valves added to the branch of Panjin Eastern Thermal Power Plant heating network were regulated according to the value.The return visits to the heating situation in the two heating seasons of 2016-2017 and 2017-2018 were carried out,according to the test data,the optimal regulation of the installation of balance valves generally achieves ideal effect,and the maximum unbalance rate of the branch is no more than 15%.Finally,other optimization schemes were given for the problems found in the survey of Panjin Eastern Thermal Power Plant,and an additional peak-shaving heat source was proposed to increase the stability of the heating network at the appropriate location of the main line.Absorption heat exchangers were installed at heat exchange stations to increase the temperature difference of heat exchanging of the primary network,and reducing the circulating flow of primary pumps in order to reduce the energy consumption.In the aspect of operation regulation,the way of periodical flow quality regulation should be adopted,simultaneously,since the actual temperature in Panjin City is relatively high in November and March,the way of intermittent regulation during this period could be adopted,to reasonably reduce the operation time of the heating network,and to achieve the purpose of energy saving while meeting the demands of users.