System and method for performance and health monitoring to optimize operation of a pulverizer mill

Patent metadata

Field	Value
Publication number	US-12405606-B2
Application number	US-202217578964-A
Country	US
Kind code	B2
Filing date	Jan 19, 2022
Priority date	Jan 22, 2021
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

Pulverizers are very critical equipment in overall functioning of a plant. They need to be controlled and monitored properly for the optimized operation of the pulverizers. A system and method for performance and health monitoring to optimize operation of a pulverizer is provided. The system comprises a digital twin that can mimic the performance of the pulverizer in real-time and assist the operators in decision making related to operation, maintenance and scheduling. The digital twin is configured to receives real-time sensor data from a plurality of data sources and provides real-time soft sensing of key health and performance parameters of the pulverizer. One more key aspect of the solution is the advisory system that alerts and recommends corrective actions in terms of parameters controlled through other equipment or changes in operation or design or changes in cleaning schedule.

First claim

What is claimed is:

1. A processor implemented method for performance and health monitoring to optimize operation of a pulverizer mill, the method comprising:
receiving, via one or more hardware processors, a plurality of data as input data from one or more data sources, wherein the plurality of data comprises:
a plurality of current and historical measurements by a plurality of sensors installed on the pulverizer mill and upstream-downstream equipment, comprising of flow rates, pressures, temperatures, concentrations and control system set points;
a plurality of current and historical coal properties data comprising of a hardness index, a calorific value and an ultimate and proximate analysis of coal; and
a maintenance and design data comprising of the pulverizer mill and, historical record of maintenance, dimensional and design specific information of the pulverizer mill;

preprocessing, via the one or more hardware processors, the plurality of data and storing the preprocessed plurality of data in a database, wherein the pre-processing further comprises:
identification and removal of outliers from the plurality of data;
imputation of missing data from the plurality of data; and
synchronization and integration of a plurality of variables from the one or more data sources using the residence time of a plurality of units of the pulverizer;

soft sensing in real time, via the one or more hardware processors, a plurality of key performance and health parameters of the pulverizer mill and coal quality parameters using the preprocessed plurality of data and a set of soft sensing models,
wherein the set of soft sensing models comprises a set of physics-based models for real-time determination of grinding effectiveness preceded by data-driven models, wherein the set of physics-based models solve a set of differential and algebraic equations representing transport, drying and grinding of coal within different zones of the pulverizer mill, and wherein the grinding effectiveness is captured by a set of coal grinding matrices representing a fraction of coal moving from a coarser bin to a next finer bin over a length of time, and the coal grinding matrix represents the grinding effectiveness, and the coal grinding matrix is used for predicting mill current pressure and mill differential pressure, wherein the physics-based models are used for the real-time determination of the grinding effectiveness by optimizing the grinding effectiveness value such that the predicted output comprising the coal size distribution matches real measurement comprising coal size distribution at the inlet and outlet of mill in the plant; and
the data-driven models include machine learning regression, Kalman filter, clustering, or classification;

post establishing the grinding effectiveness of the pulverizer mill, predicting, via the one or more hardware processors, by a plurality of condition monitoring models, a plurality of key operating events of the pulverizer mill using the soft sensed plurality of key performance and health parameters, coal quality parameters and the preprocessed plurality of data, wherein the key performance parameters comprises outgoing coal fineness, internal coal accumulation, outgoing coal flow, mill current, mill differential pressure and coal moisture, wherein the coal quality parameters comprises coal calorific value, coal hardness, coal incoming moisture, wherein the plurality of key operating events are associated with adverse conditions in the pulverizer mill, wherein the adverse conditions include one or more of a high operation cost, an operating regime shift, coal property variations, component degradation, safety risks and environmental risks pertaining to an operation of the pulverizer mill, monitoring operating regime changes and fuel quality changes, wherein the component degradation includes monitoring indicators of roller, table, and gearbox degradation, such as vibrations and current, wherein the plurality of condition monitoring models use the preprocessed data, maintenance information, mill design and mill specific information, predicted performance and coal quality parameters from the set of soft sensing models, wherein the plurality of condition monitoring models observe trends in coal accumulated which is soft sensed by soft sensing models in each zone of mill over a time and raise an alarm if there is a shift in the coal accumulated trends;
estimating, via the one or more hardware processors, a current health index and a future health index using a plurality of health index models, wherein the health index provides indication of one or more of suboptimal operation, deterioration of components and possible faults and anomalies, despite variations in upstream-downstream conditions, ambient conditions, coal property variations and operating regime changes and wherein the health index is a function of measured parameters, the soft sensed plurality of key performance and health parameters, coal quality parameters and maintenance and design data of the pulverizer mill, wherein the plurality of health index models are pre-generated models;
receiving, via a digital twin, real-time sensor data from the one or more data sources and mimicking performance of the pulverizer mill in real time;
comparing, via the one or more hardware processors, the current health index and the future health index with a threshold health index, diagnose the current health and future health of the pulverizer mill, wherein the diagnosis comprises of identifying and localization of faults, a root cause analysis of the faults, and estimating a remaining useful life (RUL) of the pulverizer mill and its components;
providing, via the one or more hardware processors, a set of operating recommendations to the pulverizer mill to mitigate the adverse conditions in the pulverizer mill based on the plurality of key operating events and the diagnosis;
recommending, via the one or more hardware processors, corrective actions in terms of the plurality of key performance and health parameters of the pulverizer mill and coal quality parameters;
providing, via the one or more hardware processors, optimal maintenance and scheduling recommendations using maintenance optimizer models, based on the estimated current health index, the future health index and the estimated remaining useful life of the pulverizer mill; and
calibrating, via the one or more hardware processors, existing models to adapt to a current performance and requirements of the pulverizer mill and the plant.

2. The method of claim 1 , further comprises enabling automatic update of models if performance of models is found below a set threshold.

3. The method of claim 1 , wherein the one or more data sources comprises a distributed control system (DCS), one or more of Supervisory Control and Data Acquisition (SCADA) System, Enterprise Resource Planning (ERP) system, a historian, a laboratory information management system (LIMS), Manufacturing Execution System (MES), Manufacturing Operations Management System (MOM), databases, a plurality of sensors, external sources, manual input, and a well sensor database.

4. The method of claim 1 , wherein the plurality of performance and health parameters comprises a grinding effectiveness index, coal accumulated in the pulverizer mill, an outgoing coal fineness, a mill current, a mill differential pressure and moisture, a motor current, a coal flow rate, an air flow rate, a hydraulic oil pressure, a roller gap, a bowl differential pressure, a lubricating oil temperature, vibrations, a classifier rotations per minute (RPM), a plurality of set points from control system, an inlet-outlet air temperature, and pressure.

5. A system for performance and health monitoring to optimize operation of a pulverizer mill, the system comprises:
an input/output i

Assignees

• Tata Consultancy Services Ltd

Inventors

• Deodhar Anirudh
• Mukherjee Tathagata
• Kumar Rajan
• Runkana Venkataramana

Classifications

• G06N3/08

  Learning methods · CPC title

• G06N3/044

  Recurrent networks, e.g. Hopfield networks · CPC title

• G06N5/04

  Inference or reasoning models · CPC title

• B02C15/04

  Mills with pressed pendularly-mounted rollers, e.g. spring pressed · CPC title

• G06N3/045

  Combinations of networks · CPC title