UI Steam Plant Measurement Systems

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The plant configuration
Team Name Rolling Timber II
Clients Scott Smith
Instructor Dr. Steven Beyerlein
Mentor Sammy Stuhlman
Group Numbers Faisal Alqudairi,

Michael Silk,

Miyako Nakayama,

Waleed Alsheikh,

Zakaria Alghamdi

Duration Summer 2018 - Fall 2018

The goal of the project is to measure and record the primary fuel variables for the wood fired boiler at the UI Energy Plant. The measurements can be used as inputs to automate the wood fired boiler combustion controls. Mass fuel flow of the wood chips, moisture of the wood chips, mass air flow, air temperature and air moisture flowing into the boiler are all necessary to optimize combustion.

Problem Definition[edit]

The objective of our capstone project as Rolling Timber II is an extension of previous work with the intent of generating an operating lab prototype that can enable full-scale implementation in the UI Steam Plant.

Team Rolling Timber I (the previous team) was able to design and build a prototype sensor for mass fuel flow and fuel moisture content. These sensors will need to be refined and then a measurement and verification process can either prove or deny the design concept. Additionally, the measurement of mass air flow, temperature and moisture content will need to be developed.


The University of Idaho Steam Plant produces steam for heating and campus buildings and sidewalks, as well as chilled water from a lithium bromide system. Steam is primarily produced in a boiler burning sawmill waste known as hog fuel.

The wood fired boiler at the University of Idaho is driven by the combustion of wood fuel and air. Mass fuel flow of the wood chips, moisture of the wood chips, mass air flow, air temperature and air moisture flowing into the boiler are all necessary to optimize combustion. Operation and control of biomass boilers has been primarily done by plant operators manually.

As of 2018, the woodchip boiler consumes approximately $ 1,000,000 per year in fuel. This is a significant savings over alternative fuels (e.g. natural gas), but could be further improved by implementation of a feedback control system to more efficiently supply fuel and combustion air.

Currently, excess fuel is supplied to the firebox of the boiler. Mr. Scott Smith, the Steam Plant Manager, estimates that approximately a 5-15 % reduction in fuel consumption could be achieved by implementation of a feedback control system, reducing operating costs and improving air quality in the City of Moscow. In addition to these tangible benefits, no other known wood-fired boiler has yet implemented comprehensive feedback control system, so implementation of this type of steam at the UI Steam Plant would be a breakthrough in biomass boiler technology.


Functional Specifications

•It is fine to use modified unit such as lbs/min or lbs/s, however, lbs/hr is a unit which is usually used in the plant.

•Source of woodchips: Cedar, Pine, and Fir (These are available in this area)

Functional Specification Table

Mechanical Specifications

Spatial Requirements

•Implementation of devices (our design) should be require little to no modification to the existing system in the plant.

•The available space within the throat is 9” wide × 84” long × 26” long. (for mass flow sensor of wood chips)

•Round duct – 24” diameter (for mass flow sensor of air)

•Rectangular duct – approximately the same cross-sectional area as the round duct (for mass flow sensor of air)

Materials for the prototype

•Mild Steel is preferred by our client.

Mass flow measurement[edit]

System Diagram Mass Flow

Fuel Mass Flow Rate Concept[edit]

Wood chips thrown from outside usually goes into a large bin. These wood chips stay there for a while and get smashed into smaller pieces by augers (rotational blades). These smashed wood chips flow into a throat and eventually get burned in a boiler after they pass the throat. The possible location to install mass flow sensor is the upper side of the throat since all the wood chips need to pass through the throat.

Flow rate system

Idea behind the system[edit]

Impact plate: The possible design idea for the mass flow measurement system was impact plate since it can fit on the given throat dimensions and is mechanically simple. Whenever wood chips hit on the plate, it causes reaction force on the plate. Hence, this reaction force over time can be measured calibrated, which enables us to calculate mass flow rate [lbm/s] or [kg/s].

Measurement Plate

Design Concepts Considered

We have two major concepts for design.

1• Design for the prototype-scale testing

2• Design for the actual implementation in the plant (full-scale)

Requirement for the measurement plate design to success

• Stick with limit availability area, because of the I-beam located under the bin.

• The pivot point needs to be on the top left (above the I-beam), so we have the impact plate lay on the load-cell always.

• We need to cover the two edges to avoid falling of woodchips outside the throat.

• Load-cell arm need to be welded to bottom of the I-beam.

• There is a rubber will be added between the arm and the impact plate, for better readings.

• The supports will be attached to the top of the I-beam and the back of the impact plate.

Additional to the design

• We added a stud driver that goes the middle of the I-beam to the back of the impact plate. This driver will help to push the impact plate away in case we want to change or replace load-cell or the rubber band.

Final design of measurement plate

Mass Flow Measurement[edit]

Software and Code

• NI LabVIEW (2018)

• DAQ Assist takes load cell signals in so we can record them in LabVIEW

Fine adjustment to integration code

• This system is calibrated to output a LBF signal.

Moisture content measurement[edit]

System Diagram Moisture Meter

How moisture content works[edit]

Possible location to install the moisture sensor

Moisture contents should be measured before wood chips go into the throat. (The reason for the target location for the moisture sensor installation, please refer to XXX). We assume that moisture content of the wood chips are all uniform for all the woodchips contained in the bin. Hence, moisture content measured from one specific location on the bottom of the bin can represent the moisture content of entire wood chips inside the bin.

Relationship between the fuel mass flow rate and moisture contents

Drier the wood chips, better they gets burn, which is related to the efficiency of the wood-fired boiler.

Hence, it is important to keep on track how much moisture contents wood chips have all the time.

Idea behind the system[edit]

Moisture content can be calculated as [%]. WCMT-HGT: This sensor was from Schaller Messtechnik, which is a company in Austria. This can be installed stationary to measure the wood chips’ moisture, so we wouldn’t need major modification on the plant to install it. The nice thing about this moisture sensor is that the manufacture already provided the calibration table so that we can find moisture content [%] according to the output current we got.

Team Members[edit]

Team members inside the plant
Faisal Alqudairi

Major: Mechanical Engineering
Graduation Date: August 2018
About: I'm a senior Mechanical Engineering student from Kuwait City. In this project, I am responsible for Meeting Agendas and Meeting Minutes. In addition, I am responsible of tracking what everyone is doing and keep the important dates pointed as reminders in the daily agendas.
Email: alqu6744@vandals.uidaho.edu

Miyako Nakayama

Major: Mechanical Engineering
Graduation Date: December 2018
About: I'm a senior mechanical engineering student from Japan. In this project, I am responsible for electrical components such as circuits and sensors and software for control system. Moreover, I am working as a team manager to make and check our daily/weekly/annual schedule for our team and remind our team members what to do by a specific due date.
Email: naka6494@vandals.uidaho.edu

Zakaria Alghamdi

Major: Mechanical Engineering
Graduation Date: December 2018
About: I'm a senior mechanical engineering student from Saudi Arabia. In this project I'm responsible for designing the measurement plate and draw it in Solid-work. Also, I'm responsible for contacting the client Mr. Scott. For every step we take there are lots of challenges. We learn from every challenge we face.
Email: algh1151@vandals.uidaho.edu

Waleed Alsheikh

Major: Mechanical Engineering
Graduation Date: December 2018
About:Hello I’m a senior ME student from Kingdom of Saudi Arabia, I’ll graduate Fall 2018. In this project I’m responsible about the project budget and wikipage. I used to work in steam plant as a maintenance guy, so I have experience on metal fabrication which it will help add more value on this project.
Email: alsh8876@vandals.uidaho.edu

Michael Silk

Major: Mechanical Engineering
Graduation Date: December 2018
About: I am a senior mechanical engineering student from Blackfoot Idaho. In this project I am responsible for circuit analysis and data acquisition. I studied electrical engineering for 4 semesters here at the U of I and I enjoy combining this knowledge with my mechanical studies for control systems projects like this one.
Email: silk6881@vandals.uidaho.edu

Document archive[edit]

Product Requirements

Value Proposition

Drawings package

Data Sheets

Project Schedule (Summer 18)

Project Schedule (Fall 18)

Power Point Presentation

Project Poster