Temperature Sensing Sootblower for Boiler Overheat Prevention
Solution Overview
Problem
Conventional temperature sensors in industrial boilers are ineffective in monitoring flue gas temperatures across heat transfer surfaces and lance tube temperatures, leading to potential overheating and unscheduled shutdowns due to the accumulation of fly ash particles and inadequate cleaning processes.
Innovation Solution
A temperature sensing sootblower with an elongated lance tube equipped with thermocouples or temperature sensors that measure flue gas and lance tube temperatures, using a data transfer device like a slip ring to transmit readings to a data acquisition unit for controlling boiler cleaning operations and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional temperature sensors are positioned in fixed locations on boiler walls, then the sensor structure is simple, but the sensors cannot monitor flue gas temperatures across heat transfer surfaces
Solution Approach 1:
The sootblower lance is equipped with both cleaning functionality and temperature sensing capability. The thermocouple integrated into the lance serves dual purposes: it monitors flue gas temperature during the cleaning cycle and provides data for process optimization, eliminating the need for separate fixed temperature sensors
Solution Approach 2:
The temperature sensing system transitions from static fixed sensors to dynamic mobile sensors mounted on the moving sootblower lance. This allows temperature measurements at multiple locations across heat transfer surfaces as the lance moves, providing comprehensive thermal mapping capability
2Productivity
If the lance tube is exposed to hot flue gas inside the boiler, then cleaning effectiveness is improved, but the lance tube may overheat
Solution Approach 1:
The thermocouple provides real-time temperature feedback from the flue gas and lance tube to the control system. This feedback enables dynamic adjustment of sootblower operation parameters, including cleaning fluid flow rate and lance exposure time, to maintain optimal cleaning effectiveness while preventing lance tube overheating
Solution Approach 2:
The system establishes minimum cooling flow requirements in advance based on lance tube material properties and expected thermal conditions. The control system ensures adequate cooling fluid flow is maintained before and during lance exposure to hot flue gas, preventing overheating before it occurs
3Temperature
If cleaning fluid flow is increased to prevent lance overheating, then lance temperature control is improved, but energy consumption increases
Solution Approach 1:
Real-time temperature measurements from the thermocouple enable the control system to adjust cleaning fluid flow rate dynamically. The system increases cooling flow only when and where temperature thresholds are approached, rather than maintaining maximum flow continuously, thereby optimizing energy consumption while ensuring lance tube temperature control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides real-time temperature monitoring and control, enhancing boiler efficiency, preventing overheating, and optimizing cleaning processes by allowing for intelligent deposit removal and maintaining optimal combustion and cleaning fluid flow.
Implementation Method 1
The temperature sensor comprises a thermocouple positioned within the groove
Implementation Method 2
the blowing fluid, which also acts as a cooling medium, needs to be supplied continuously to the lance
Implementation Method 3
The minimum amount of the cleaning media required to prevent the lance from overheating is known as the minimum cooling flow
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A temperature sensing sootblower that may be configured as a modification to an existing sootblower or a specially constructed sootblower that, in addition to its normal soot blowing functions, has the capability to measure the flue gas, lance tube, and/or cleaning fluid temperatures. One or more thermocouples or other temperature measuring devices are carried by the sootblower lance tube that is inserted into the boiler. This allows for the temperature of the flue gas, lance tube, and cleaning fluid to be measured as the sootblower lance tube is inserted into and retracted from the boiler. Multiple temperature measuring devices may be located on the sootblower lance to measure the temperature across heat transfer surfaces and at different locations along the lance tube. A data transfer device transmits the temperature measurements from the rotating thermocouple to a non-rotating data acquisition unit for use in boiler cleaning and other operations.