project team a

8/10/2019 Project Team A

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Faculty of Information Engineering

Polytechnic University of Turin

System Design Engineering Perspective

(Centralized Heating System Development)

II Level Specializing Master in

Automatica and Control Technologies

Supervisor: Eng. Federico Bari

M.Ali Akhras

Ahmed Al Albalasie

Almir Becirspahic

2011/2012


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Contents Table

CONTENTS TABLE.................................................... 0

CHAPTER 1 .................................................................. 1

Mission Statement ................Error! Bookmark not defined.

CHAPTER 2 .................................................................. 2

Brainstorming ........................Error! Bookmark not defined.

CHAPTER 3 .................................................................. 8

Mission Scenarios / Phases .........................................................8

CHAPTER 4 .................................................................. 9

Life Circle .......................................................................................9

CHAPTER 5 ................................................................ 10

Problems Domain for Each Phase ......................................... 10

CHAPTER 6 ................................................................ 11

The Use Cases of Each Life Circle Phase ................. ............ 11

CHAPTER 7 ................................................................ 12

Operations and Activities ......................................................... 12

CHAPTER 8 ................................................................ 12

Functional , Performance and Constraint Requirements1Error! Bookmark not

defined.

CHAPTER 9 ................................................................ 15

System Functional Possible Architectures and

System / Subsystem Interfaces ............................................... 15

CHAPTER 10 .............................................................. 17

System Architecture Trade-OFFs ........................................... 17


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Digital Control TechnologiesSystem Design Engineering PerspectiveWork Project Team A

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CHAPTER 1

Mission Statement

The main goal of the project is to convert old centralized heating systems into new

innovative system and metrological methodology that sophisticate the thermal comfort

requirements for each user and the energy saving issues as well as to other technological

aspects like upgrading, remote control capabilities, easiness of usage, and fault detection and

intelligent diagnostic system. One of the main features is to make the system automated as

possible to facilitate and optimize the heating system operation.


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CHAPTER 2

Brainstorming

General goals:

1. Efficient local control of the temperatures inside rooms through a bi-mode system(automatic and manual).

2. Increase savings of energy as much as possible without effecting negatively on theuser requests.

3. Optimization of heating distribution system and computation of energy consumptionfor each subscriber.

4. Easiness of usage for all the users and control flexibility by many tools like localremote control device or mobile phone.

5. Improvement of maintenance operations through a smart diagnostics system toincrease the life cycle of the heating system.

Troubles of the old centralized heating systems (vertical distribution):

1. Centralized old heating systems do not usually have any local (flat) temperaturecontroller.

2. Users pay on the basis of the flat area, not based on measurement of heating energyabsorption.

3. Flat closer to the common heater are overheated and flat far from the heater are too

cold

4. Centralized old heating systems are usually semi-automated or completely manuallycontrolled, therefore this create troubles to the users and missing of comfort.

5. Remote control capabilities and other sophisticated control specifications that arehighly requested nowadays like remote control and operation scheduling.


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Centralized heating system improvement:

1.

Local control system could be used to control the temperature in rooms by adjustingan electronic valve according to the desired temperature.

2.

Payment system should be based on the heating energy consumption for each flat

and its conditions like its location.

3. Electronic valves that have the ability to be controlled through a microcontroller

should replace manual valves.

4.

The new system is able to diagnose a possible fault in the system

5.

The new system includes a remote control and keypad to control the system.

Main ideasdescription:

Local ControlSystem DefinitionThis system is made principally of amicrocontroller board used for controllingthe temperature in rooms, computing theheating energy consumption, acquiringthe measurements related to each radiator.

Original problem The radiators in old heating systems arecontrolled manually, so the user has toadjust the valve opening amount using amechanical valves that are standard in allthe flat. The temperature scale is usuallydesigned to give many levels of valves

opening without knowing each levelcorresponds to what temperature. If wehave a high building, then the heatingwater temperature in the last floor is notthe same as in the first floor for example,this create some problems for the user toknow how much he/she has to open thevalve in order to provide an adequatetemperature of interest.

Solution The main objective of having anautonomous controller for each flat is to

control the electronic valves installed on


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Page 4of 18

the radiators in the flat basing on desiredtemperature and the actual room

temperature as a feedback to thecontroller.Therefore in the high floor flats, thecontroller should open the valves morethan in lower floor flats in order to reachthe desired temperature. This is becausethe hot water temperature in the first caseis usually lower than in the second case, soit will be necessary to allow to moreamount of hot water to flow through theradiator.

MeasurementSystem

Definition The system is composed from a set oftemperature installed directly on theradiators and liquid fluid sensorscompacted in the electronic valves.Another set of temperature sensors arerequired to measure the temperature ofrooms that are used to provide the localcontroller with the feedback signal toadjust the valves opening until reachingthe desired temperature.

Original problem The old heating system does not have anymeasure any physical quantity related tothe energy, specially the temperature offlowing hot water through the radiator, sousually the payment system is based ondividing the total consumption of heatingenergy by the number of flats even if someof the flats did not consume anything orconsumed less than the others, the shouldpay the same amount of money. Inaddition, it does not take into account the

fact that the heating water reaches thehigh floor flat colder because of height andabsorption of the heating energy in lowerfloor flats as well as the distance from thecentral heater has a role in this variation ofthe heat water temperature.

Solution The sensors installed on the radiatorprovides information to the control systemabout the actual temperature of the hotwater and its flow rate, so the processingsystem compute the amount of energy

consumption for each radiator in


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Page 5of 18

proportional to the ratio of the heat watertemperature to its flow rate.

Instead the second sensor set solve theproblem of tuning the valve opening byfeedbacking the actual temperature in theroom to the controller. This set is actuallyvery important to maintain thetemperature at the level of interest.

Remote Control Definition Remote control devices are mainly madeof a transmitter and a receiver.

Original problem Since the old heating system does not havea local control capability, therefore this

could be a big problem for disable or oldpeople in which they should adjust thevalve manually. Another important issuethat must of the parents looking forwardis to have a remote control possibility toprotect their kids from radiators heat. Inadditional to what already mentioned, aremote control option is highly requestednowadays in the market due to comfortneeds by the clients.

SolutionIn case of local remote control, thecommunication between the transmittingand receiving circuits is performed via IR(infrared), instead in case of externalremote control via mobile phone theconnection method is more complex.

CommunicationSystem

Definition The communication system in generalconsists of a set of nodes connected bylinks or edges. Communicationnetworking system suggested in thisproject is from Hub Network type. The

hubs in this network are the central andlocal controllers. Other nodes in thenetwork are the sensors distributed overthe system as well as actuators (valves)that are mono-directionally connected tothe hubs. Remote control devices can beenseen as nodes bi-directionally connected tothe hubs. The links or communicationmedium in this network depends on thepair of nodes linked to each other.however, the communication medium is

mainly based either on IR or wireless.


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Original problem In the old heating system, components donot have the capability to communicate

among each other or in more developedsystems, all the components are connecteddirectly to the central control unit. Thistype of networks is usually very slowsince the control unit should process allthe information coming from othersystem elements and then send theappropriate response to each one. Anotherimportant problem is the communicationthrough cables. This actually makes thelinking system more complicated and

undesired by the users because of its badappearance as well as its high number ofproblems.

Solution Communication problems could be solvedby using wireless and IR networksconstructed by Hub architecture. This typeof networking provides us with a non-centrality control over network. Here eachhub has the ability to work as a masterover its slaves. Nodes related to a certainhub exchange information with theirmaster, and then the master is authorizedto make any decision without referring tothe central master hub. However, hubs canalso communicate among each other at ahigh level. In other words, each hub playsthe role of a master and governs its relatednodes. The central master hub receiveshigh level communications only fromother hubs like messages about controlsubsystems (hubs) and has a dominationover all the network though the hubs.Another advantage of the wireless and IRnetworks is the remote control capabilitiesas well as saving space without any needto add cable that increase systems faults inaddition to its bad appearance.


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CHAPTER 3

Mission Scenarios / Phases

heater

diagonastic stage

alarm to subsystem

main valve

pump

centralmicrocontroller

diagonastic stagelocalmicrocontroller

sensors

electronic valves

rediator


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CHAPTER 4

Life Circle

The life cycle of an embedded system varies dramatically, from processors embedded in

disposable consumer goods to applications requiring maintenance and support for decades.

Designing an embedded system often requires taking into account the complete product life

cycle, from initial product concept, through its operational period, and into replacement with

newer equipment. While the design phase is covered by other topics, areas of specific

concern to a life cycle perspective are: an accurate life cycle economic model to guide

engineering trade-offs, taking into account requirements for logistics and support over theproduct operational period, and issues specific to refurbishing/retiring/discarding the

system at end-of-life. While the term "life cycle" has different meanings to different technical

communities, the central idea is to expand the traditional engineering emphasis on the

"design cycle" to encompass optimizing utility, profits, and tradeoffs across the entire

lifetime of the embedded system being designed.

requirements from theclients

design step for theadditional part (conceptdevelopment)

manufacturing processdesign for the additionalpart

production for theadditional part

install the system

Configration

test the system ( if it is okactivate the system)

system usage

upgrades

retirement/ disposal


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CHAPTER 5

Problems Domain for Each Phase

Interaction

1-User and our device

2-Heating energy exchange between the surrounding medium and upper, lower flats also

and with other rooms from the same flat

3- Heating energy exchange between the surrounding medium and the environment

outside the flat

4- -Heating energy exchange between the surrounding medium with other rooms inside the

same flat


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CHAPTER 6

The Use Cases of Each Life Circle Phase

1-tracking the desired temperature

Power on form microcontroller extended

Electronics valve included

Sensors included

Central and local micro controller included

Central and local micro controller included

Pump include

Heater include

2- alarm system for some problems

Power on for microcontroller extended

Central micro controller included

sensor included

3- measuring the heating energy bills for every flat

Sensors included

Memory included

Central microcontroller included

Communication system included


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CHAPTER 7

Operations and Activities

COMUNICATI

ON SYSTEM

ACTUATORS

LCD

SENSORSLOCAL

CONTROLER

CENTRAL

CONTROLER

USER

PROVIDER

DIAGNOSTIK

SYSTEM

KEYPAD

REMOTE

CONTROL

STORE


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CHAPTER 8

Functional , Performance and Constraint Requirements

a- central Microcontroller :

functions:

the system must record the data from every flat

the system has the ability discover some problems if it is happened

the system has the ability to calculate the heating energy bills for every flat

constrains:

number of digital inputsnumber of digital outputs

number of analogue inputs

the ability to connect it to LCD

the ability to connect it to keypad

the ability to connect it to memory

wireless communication port

b- local Microcontroller :-

functions:

-the main function of the subsystem to control the opening of the electrical valve

basing on the temperature and the flux water measurements

-the subsystem must display the reading of measurements in addition to heat energy

Consumption.

-The subsystem has the ability to scheduling it is functions according to the user

request,

- the subsystem shall estimate the temperature of flat.

constrains:

wireless communication port

number of analogue outputs

number of analogue inputsthe ability to connect it to LCD

the ability to connect it to remote control

the level source for the microcontroller

c-

electronic valve:-

function:-

-to open and close the valve with relative to the input signal.

-measure flow rate

Constraint

- the size for this sensor


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Page 13of 18

- the ability to communicate by using wireless technique

- the ability to work by using battery

-

system should be functionally and structurally robust with respect to high

temperatures.

d-

Temperature Sensor

e-

functions:

measure flow rate

Constraint

The sensor is suitable to medium.


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CHAPTER 9

System Functional Possible Architectures and System / Subsystem

Interfaces

Workspace

Subsystems

Central System

Centalcontroller

comunicationsubsystem

Local controller1

Sensors Actuators User Interface

Display Keypad remote control

Processingsystem

local controller2

local controllerN

Memory Processorpower

subsystem

battaryelectrical

source

diagonasticsubsystem


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System and subsystems vs. Functions

Temperatur

e controlScheduling

Computation

of heat energy

consumption

Fault

detection

Central control unit x xLocal controller x x

Temperature sensor x x

Flow rate sensor x x

Diagnostic subsystem x

Communication subsystem x x x x

Remote control device x x

Electronic valve x x

LCD x x

Storage device x x

Keypad x x


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CHAPTER 10

System Architecture Trade-OFFs

Data Acquisition: two possible methodologies of data acquisition by the provider could be

applied to the system. However, the heat energy consumption data are stored for each

radiator in the main processing unit database and can be combined and summed for each set

of radiators representing a certain flat:

- Methods I: in this method, the data file can be collected directly by company

employer via USB.

-Method II: in this method, a copy of the data file can be sent directly to theprovider via an internet connection.

However, the method II is better and more practically efficient.

Calculation of heat energy consumption: as we discussed in the project, the payment

system is based in principal on the measurements of hot water temperature and its flow rate.

Here we would like to propose two different methods as the following:

-Method I: in this case, a couple of flow rate and temperature sensors should beinstalled on each radiator. This can be highly efficient but more costly. On the

other hand, following this method could complicate the system more due to the

high number of required sensors installed on the radiators over the heating

distribution circuits.

- Method II: a reduced configuration of the measurement sensors net is proposed in

this method in which it will be enough to install only one couple of flow rate and

temperature sensors at the input and only one temperature sensor at the output of

each heating distribution circuit. The total energy can be calculated by the

formula:

Since that the total heat energy is distributed over all the radiators installed on the

given circuit, therefore we can write the following:

Let n is the number of the radiators installed on a given circuit and i is a given

radiator. Therefore the energy for each radiator is at max load.


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The max energy for each radiator is given by:

are coefficients calculated by one of estimation methods like Kalman filterbasing.

Now suppose that the controller opens the electronic valve on a certain angle over

360 degrees that stand for the full load, the percentage of the valve opening for a

given radiator can be multiplied by the max energy to calculate the consumed

energy over this radiator. This can be performed directly by multiplying the

controller output voltage ratio to the max voltage by the max energy for a specific

radiator.

Over the time, we can compute the energy consumption per second for each

radiator.

However, the method II is less precise than the method I but on the other hand, it

is less expensive and simpler at the level of complexity of the system

project team a

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