Boiler Control Solution: Instruments and Solution for Automatic Boiler Control

Essential Equipments for Industries

Boilers are used in a broad range of industries such as electric power, pharmaceuticals, chemicals, ceramics, and paper and pulp. Amid the rising energy costs, tightening environmental regulations, and increasing awareness of safety as of late, the needs for high efficiency operation, low emission operation, and safe and stable operation of boilers are growing.

Increasing Efficiency and Lowering Emissions of Boilers

In order to ensure the air and fuel are combusted at an optimal ratio, the waste of fuel is eliminated, and the exhaust gas is cleaned, real-time monitoring of the oxygen concentration of combustion gases is required. Equipped with an oxygen sensor unit with a longer life span, the Zirconia Oxygen Analyzer ZR series are capable of measuring an oxygen concentration with high reliability. The Stack Gas Analyzer SG700 monitors exhaust gas components such as NOx, SO₂, and CO₂ in order to ensure low emission operation.

Safe and Stable Operation

A single-loop controller can be used to properly distribute control functionality. Offering the advantages of flexibility of building distributed control systems, simple maintenance, compatibility with conventional systems, and the like, the YS1000 Series of Single-loop Controllers are ideal for safe and stable operation at low costs.

Monitoring the drum level and steam flow rate in accurate at any conditions

In order to ensure highly efficient and safely operated boilers, it is also indispensable to accurately monitor the drum level and steam flow rate. The EJA and EJX Series of Differential Pressure Transmitters are capable of measuring the drum level with high stability even in actual applications at high temperatures and high pressures. The DY Series MV TYPE of Vortex Flowmeters with a simple construction employ a built-in sensor to measure the steam mass flow with high reliability.

Why Buy Yokogawa?

Yokogawa offers a wide variety of sensors and controllers that are used to monitor and operate boilers, and contributes to increasing the efficiency and environmental performance of boilers, as well as ensuring their safe and stable operation. We want you to explore Yokogawa's sensors and controllers in order to increase the efficiency and environmental performance of your boilers, and ensure their safe and stable operation.

Drum Level Measurement

Overview and Problems

• Drum level measurement
• High stability measurement required under large static pressure change 

Solution

• Field proven silicon resonant sensor guarantees long term stability
• EJA: 0.1 % of URL 5 years 
• EJX: 0.1 % of URL 10 years 
• Under all conditions (temperature, static and over pressures) 

Benefits

• Long term high stability measurement is realized under actual plant conditions

Combustion Control

Overview and Problems

• Perform safe and stable control at low cost
• Lower levels of emission output 

Solution

• Simple programming by Function Block wiring method
• Cascade primary direct control
  - Stable level control when boiler is started
• Cross limit control calculation
  - Air and flow are calculated so that air flow always exceed fuel flow to prevent incomplete combustion and explosion
• Feed forward control
  - The main stream pressure and feed water level are controlled quickly in response to changes in the main stream flow

Benefits

• Reduced debugging time
• Improvement of the reliability of programs
• Safe and stable control at low cost

Steam Flow Measurement

Overview and Problems

• Flow measurement for utility steam
• Conventional orifice flowmeter requires complicated, high cost installation and is not accurate

Solution

• Inline flowmeter
• Built-in temperature sensor, Digital YEWFLO MV type
• Steam mass flow measurement without additional temperature sensor/transmitter and flow computer
• Accuracy 2 % of reading

Benefits

• Low installation and operational costs
• Safety operation to reduce leakage points
• Save energy by accurate measurement

Combustion Control

Overview and Problems

• O₂ control for optimum combustion
• Short sensor life by clogging

Solution

• Long life sensor with molecular bonding and special coating
• Cell life prediction

Benefits

• Fuel cost reduction
• Preventive maintenance
• Protect the environment, CO₂ reduction

Combustion Control

Overview and Problems

• O₂ control for optimum combustion of large-sized combustion equipment
• High installation cost for multipoint measurement

Solution

• Maximum 8 detectors can be connected to one AV550G converter
• O₂ measurement of multiple points, individual concentration and average values

Benefits

• Accurate control by multipoint measurement
• Installation cost reduction

Exhaust Gas Analysis

Overview and Problems

• Air pollution control by continuous emissions monitoring
• High maintenance frequency 

Solution

• Simultaneous measurement of up to five components, NO_x, SO₂, CO, CO₂, O₂
• Sample conditioning system designed to reduce maintenance
• No moving parts in the sensor 

Benefits

• Accurate control by multipoint measurement
• Installation cost reduction

Technologies Commit Users' Benefits

Our Goal

Our shared goal is customer satisfaction through operational excellence. Yokogawa has brought true innovations to industry. We are committed to ensuring accuracy, reliability, and safety of your production system throughout your business life cycle. Our comprehensive solutions and expertise help you achieve more results with less total costs of ownership. Below key technologies shall aim for your operational excellence.

EJA/EJX Silicone Resonant Sensor

By micro-machining the resonators directly within the single crystal silicon material we are able to derive the maximum benefits from the elasticity of the single crystal silicon material while enhancing sensitivity and repeatability. The properties of the resonators remain constant over time. This makes DPharp the ideal pressure sensor for harsh industrial automation environments. DPharp delivers stability, repeatability and reliability that you can rely on.

DY Key Technology

Spectral Signal Processing (SSP) technology is built into the powerful electronics of the digitalYEWFLO vortex flowmeter, enabling new functions. SSP analyses the fluid conditions inside the digitalYEWFLO vortex flowmeter and uses the data to automatically select the optimum adjustment for an application, providing features never seen before in vortex flowmeters.

YS1000 Dual CPU

With dual-CPU construction, manual control capability and display continues even if an abnormality occurs on one of the CPUs. If controller self-diagnostics detects a control circuit failure, the controller can suspend analog/digital output, switch to manual mode and allow manual control by operator.

Zirconia Oxygen Analyzers

• Get a long service life and stable operation with a Zirconia sensor
• Sensor replacement is easy
• A molecular bonding method completes installation of platinum electrodes, and its inherent connection prevents separation of Input signal Frequency analysis (SSP function) platinum from the Zirconia element.
• A lead-less electrode design eliminates electrical disconnection.
• Special coating protects the platinum and prevents the sensors from deteriorating.
• No special tool is required for cell replacement.