Research On Constant Flow Control Operation Parameters And Imbalance Of Heating System

In China, with the steadily increase of the centralized district heat-supply coverage, getting greater economic and social benefits with less energy consumption, protecting of resources and environment, guaranteeing citizen's economic sustainable development and meeting citizen's demand of raising living standards attract more citizen's attention than ever before. Heating regulation is an important mean of ensuring heating quality and energy-saving in the heating system operation. As the city centralized district heat-supply system is complex, this thesis only studied the problem of heating system regulation in various conditions and energy-saving measures we should take.This thesis has studied the regulation for the single-pipe system which was used in most of existing buildings, especially focused on the vertical imbalance among different floors, in other words the up and down floors'temperatures are different from each other and the room temperature is far from its design temperature. Several effects have been calculated, and the way that influenced the indoor temperature has been studied.Firstly, some fators about reducing the heat imbalance were studied in calculating the building's heating load. And distinguishing the primary and the secondary effects in vertical imbalance was the most important. The basic adjustments and formulas of constant flow control were simply studied. The effects of indoor temperature have been found out by the study in constant flow control formulas.Secondly, each effect was calculated in the constant flow control formulas. As the ways that influenced indoor temperature were not the same, different analytical methods were taken in this thesis. The temperature of each floor is recursively calculated by Matlab when outdoor design temperature and the flow were different. In addition, heating area selected excessively which was prevalent in existing building was explained.Finally, the vertical imbalance caused by flow changing and heating area selected excessively was studied using Statistics and advanced Mathematics. The selects of outdoor design temperature were compared when flow was changing in constant flow control. Then some valuable conclusions about the design and control of existing buildings were given.