Application Research On Absorption Heat Pump In Drying Section Of Paper Machine And New Type Thermal Control System Design

At present,the steam condensate thermal system based on an adjustable heat pump widely used in the dryer section of the paper machine can effectively recover the waste heat and energy of the dryer section of the paper machine and reduce the energy cost of the dryer section.However,when the steam pressure of the combined heat and power supply of the combined heat and power is reduced,the working capacity of the traditional heat pump is reduced,and the phenomenon that the temperature of the condensate discharged from the drying section is high and the recovery of waste heat and energy is not complete enough.In order to further recover the residual heat and energy in the dryer section of the paper machine and reduce the energy consumption in the dryer section,this paper conducts an application study on the absorption heat transformer,attempts to use the temperature-rise absorption heat pump in the dryer section of the paper machine,and transforms the traditional heat pump The thermal system can recover and utilize the residual heat and energy of steam condensate and humid hot air to a greater extent.The main work of this article can be described as follows:I.Feasibility analysis of heating type absorption heat pump applied to drying section of paper machineThe paper first introduces the current thermal process of the dryer section of the paper machine,the working mechanism of the single-stage absorption heat transformer and the application of the improved circulation structure absorption heat transformer;Feasibility analysis of heat pump application.The application demand analysis focuses on the analysis of the current status of the waste heat and energy recovery of the existing thermal system in the dryer section of the paper industry,and provides a clear application background for the introduction of absorption heat transformers.The feasibility analysis is mainly in the waste heat recovery of the dryer section of the paper machine,whether the temperature-absorbing absorption heat pump can be used in the dryer section of the paper machine,and what structure of the temperature-absorbing absorption heat pump can effectively recover the waste heat and residual energy of the paper dryer.Ⅱ.Design of Thermal System of Drying Section of Paper Machine Based on Heating-up Absorption Heat Pump and Its Benefit AnalysisAfter a comparative study,we chose a double-absorption absorption heat transformer as the waste heat recovery equipment,and on this basis,we designed a new thermal system combining this equipment with the thermal system in the paper dryer.In addition,the key to whether the double-absorption absorption heat transformer can be used in the papermaking drying section is also the economics of the heat pump,that is,whether the investment cost can be recovered in a short period of time.This part of the work is to simulate and calculate the energy consumption and flow of the thermal system,compare the energy consumption before and after the application of the double absorption heating absorption heat pump,and analyze the calculation equipment in papermaking from the perspective of the actual project one-time investment cost and the resulting economic benefits.Utilization value of waste heat recovery in the dryer section.Ⅲ.Research on Control Strategy and Control Scheme of New Thermal SystemIn the current application background of paper machine dryers,there are few related researches on absorption heat transformer control systems.In view of this situation,this paper studies the application technology of double absorption absorption heat transformers for the control system of waste heat recovery in paper machine dryers A control system based on the double-absorption and absorption heat transformer waste heat recovery system is designed,a process flow chart with measurement and control points is given,the control points and control difficulties in the control process are analyzed,and the corresponding maximum performance is proposed for the control difficulties Coefficient indirect control strategy.The purpose of this control strategy is to obtain the maximum coefficient of performance of the absorption heat transformer waste heat recovery system to recover as much waste heat and energy as possible in the dryer section.Ⅳ.Design and Implementation of a New Thermal Control System Based on S7-300 Series PLCThe thesis takes S7-300 series PLC as the core to constitute the DCS control system,and completes the realization of the new thermal control system.The specific work includes three aspects:control system hardware configuration,software design and debugging,designing the hardware configuration and software system to meet the needs of the new thermal system,and finally testing the function of the programming software through PLCSIM to ensure that the application software realizes the new thermal process control and Indirect control of the maximum coefficient of performance.