Design Of The Computer Monitored Control System Of Saturated Vapor And Apply Research

High temperature, high pressure and high dryness vapor is needed in thick oil extration and the energy of vaporization heat is used to heat up the thick oil, so that the thick oil can be diluted and extracted. According to different geologic structure and deepness of well, the vapor pressure and flux varies. Along with the pressure changing the vapor density affects the flow measurement primarily, so the vapor density compensator is very important to the vapor measurement system. The existing density compensator model does not fit high temperature and pressure saturated vapor, the density compensator precision is low and causes big error in saturated vapor measurement.Based on saturated vapor computer monitored control system of LiaoHe oil field, this article introduces the design of this system in detail. The system has three layers: management layer, monitored control layer and field layer. The field layer which includes valves and meters is to accomplish field control and data collection. The monitored control layer which includes IPC and configure software is to monitor and translate the monitoring data. The management layer which includes IPC, Delphi and SQL Server2000 is to store, query the monitoring data and print report. The whole system which uses RS-485 to share information has beautiful interface, the diversiform function, and the easy manipulation.This paper lays special emphasis upon the density compensator model for saturated vapor alterable work condition. Usually the low temperature and low pressure density compensator model uses least squares method segment to fit the pressure-density table by linearity. However, along with the increasing pressure the density error is also increasing, which results in degraded measure precision of high temperature and high pressure saturated vapor. In order to improve the density compensator precision, firstly density specimen is interpolated when the pressure is bigger than 10MPa. Secondly, least squares method is used to curve fitting pressure-density table by linearity, parabola and thrice polynomial respectively. Lastly, by comparing the emulational error the optimal equation is proposed.This density compensator model has been used in saturated vapor measurement system of LiaoHe oil field successfully, its most reversely error is 3%. This model has promotion value in saturated vapor flux measurement of alterable work condition.