The Hydraulic Characteristics Of Pipe Networks And Operation Control Of Heating Network With Double-heat Sources

Heating net work with multiple-heat sources can save energy conservation,lower system operating costs,improver economic efficiency,so it would be used in the application of heating more and more.In this paper,the characteristics of the pipe network with double-heat sources was analyzed by the software of Pipe Flow Expert, and the experimental was established to analyze the changes of the four kinds of typical hydraulic conditions of the heating net work with double-heat sources,then,a adjustment method of heat net work with double-heat sources was proposed.To further identify the characteristics of hydraulic and thermal of the heat network,the authors and thermal company in Baoji test,analyze the hydraulic regulation and the working conditions regulation of the heating net work with double sources.This reseach laid the foundation for the project design and operation scheduling.The analysis of the Pipe Flow Expert software mainly balances the flow rate and the pressure which provides inside the networking and carry on take care of design and reformation of the networking system conveniently,the changes of the hydraulic conditions of a heat net work which composed of 5 hot customers connects into the single hot source and the double hot sources ware analyzed by the software of the Pipe Flow Expert.Research shows as follows:(1)The system has not carried on initially adjustsLeave from the heat source code from the beginning(the same below),the press differ of hot customer1 is 13.51 mH₂O,the press differ of hot customer1 is 11.91 mH₂O, the press differ of hot customer1 is 11.99mH₂O,the press differ of hot customer1 is 4.00mH₂O,it was too march from design request,so the system was unstable.After the initially adjusts,the press differ of hot customer1 is 11.51 mH₂O,the press differ of hot customer1 is 8.51 mH₂O,the press differ of hot customer1 is 7.14mH₂O,the press differ of hot customer1 is 3.99mH₂O,attain design request,and the system stable.So we know that the initially mediates is playing the vital role in the pipe network operation stable aspect.(2)The heat source export has accident operating mode(the valve A throttle, its opening is 70%)The press differ of hot customer1 is 9.32mH₂O,the press differ of hot customer1 is 4.52mH₂O,the press differ of hot customer1 is 3.96mH2_O,the press differ of hot customer1 is 1.69mH₂O.When the valve A throttle,the total drag of network increases in a big way,but the total flows world reduce.The net resistance number of main network and the user branch's network has not change,so each hot user's flow distribution proportion has not changed,it is that it would according to the identical imbalance.Because change of the operating mode,so the current capacity reduces, thus the hydraulic pressure chart of change operating mode compared to the hydraulic pressure chart of design operating mode must become gentle somewhat.(3)The main net work accident operating mode(the valve B throttle,its opening is 70%)The press differ of hot customer1 is 12.52mH₂O,the press differ of hot customer1 is 7.26mH₂O,the press differ of hot customer1 is 6.01mH₂O,the press differ of hot customer1 is 2.95mH₂O,We know that when the valve B throttle,the water line ball of the delivery pipe and the return pipe will become gentle,and the delivery pipe water line ball will present a sudden drop in this spot(valve B).After the hydraulic operating mode's change,the resistance number of the user which after the valve B has not changed,but the total applied pressure was reduces,the applied pressure of users which after the valve B also defers to by the similar proportion reduction;but the user which before the valve B,its current capacity will increase,its applied pressure will also increase,but not will defer to certain proportion to increase.(4)One of the user accident operating mode(the valve C throttle,its opening is 45%)The press differ of hot customer1 is 12.99mH₂O,the press differ of hot customer1 is 10.00mH₂O,the press differ of hot customer1 is 8.17mH₂O,the press differ of hot customer1 is 4.23mH₂O.We may see that the pressure between the supply pipe and the return pipe at hot customer2 increase.Because under this operating mode,the total drag number of the network would increase,but the total flow would reduce.From the heat source to the hot customer2,the work pressure between the supply and return pipes becomes gentle somewhat.But the work pressure between the water supply and return pipes at the hot customer2 increase,thus the following user's flow rate increases according to the same proportion,and causes the water line ball of the following supply pipes and return pipes quite steep.In the multi-heat source networking operation,the heat source number(including unit's number)was change along with the change of outdoor temperature unceasing,so the change of operating mode would be more complex.This paper has carried on the exploration and the analysis of the thermal power plant heating ability,the energy conservation movement pattern and two heat source malfunctions for spare mutually based on the heating incorporation experiment between boiler of Yujianpu and the thermal power plant.Research shows as follows:(1)Considered the heat source can provide a big heat quantity,and can obtain the adjustment when the heating demand,choused the double heat source system.Looking from the heating expense,when heating areas from 1,000,000 to 1,600,000 scopes should use the plan 1,Meaning that at the beginning of the heating and at the end the heating take the thermal power plant as the independent heat source,and at the freeze of the heating take the Yujianpu boiler as the main heat source,the thermal power plant was the auxiliary heat source.(2)Along with Baoji central heat supply develop fast,when the heating area increases between 1,700 and 2,000,000 scopes should use the plan 2 of plan 3,meaning that thermal power plant was the main heat source in the all heating time,the Yujiapu boiler was the auxiliary heat source.Based on the analysis of the hydraulic condition and the thermal energy operating mode adjustment of branched pipe network with double heat source,the paper had provided the powerful basis for the later practical work...