European Project Semester at ISEP - EPS@ISEP

Report

Please write here the different contributions that will be integrated in the final report

Do not forget to adopt and follow stricly the International System of Units conventions in your report.

Abstract

How can the international team make humidifier for data center? How can they do it without any knowledge about it? They are Erasmus students from Spain, Portugal, Poland and Hungary. They have had a lot of problems with this project. Starting from communication and English language and finishing on technical troubles. In this report you can find information how they was working during 4 month. Do they make working solution?

Glossary

Spray nozzle is a precision device that facilitates dispersion of liquid into a spray. Nozzles are used for three purposes: to distribute a liquid over an area, to increase liquid surface area, and create impact force on a solid surface.

Air compressor is a device that converts power into kinetic energy by pressurizing and compressing air, which is then released in quick bursts.

PLC is an programmable logic controller (PLC) or programmable controller that is a digital device used for automation of electromechanical processes.

Microcontroller is a computer-on-chip containing a processor, memory and peripheral input / output.

Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

Java is a programming language and computing platform. It is the underlying technology that powers state-of-the-art programs including utilities, games, and business applications.

Tomcat is a Java Servlet container and web server from the Jakarta project of the Apache software foundation.

Notepad++ is a simple text editor for Microsoft Windows.

Introduction

Within the European Project Semester at ISEP, it was proposed to build a humidifier with a Web interface. Thus, this report describes the inicial phases of construction of the humidifier.

This project will have as its main motivation the confrontation with real life and teamwork. We also have a great opportunity, not only to put into practice the knowledge acquired, but also to learn new things.

The goal is to develop a humidifier with a Web interface for a server room of 80 m³.

The final product must:

  1. maintain of a relative humidity between 40 % and 70 % (+- 5);
  2. distribute the generation of water vapour within the room;
  3. have two days of autonomy;
  4. be placed on the floor of the room;
  5. include water and humidity alarms;
  6. have an on-off switch;
  7. be compliant with the EU Directives 2006/42/CE 2006-05-17 and 2006/95/CE 2006-12-12;
  8. have a composite material structure to hold the control unit and the water container;
  9. include a life-cycle analysis.

We have as available parameters:

  • air flow;
  • incoming air temperature;
  • chiller input temperature;
  • budget limit: 900 €.

Knowing all the requeriments specified by the customer, we hope complete the project successfully. For this to happen, initially, we divided the work into four black boxes designated as humidifier, tank, control and Web interface and, then, for a better organization the work, we developed a Gantt Chart and divided the tasks between us.

Task Responsible
Humidifier Mihály and Mateusz
Tank Marc and Mihály
Control Fátima and Marc
Web interface Fátima and Mateusz

The gant chart and division of work were only assumptions. We don’t strictly follow this. We had a lot of delays. We have changed our idea. We had to wait for the parts.

This report is structured in six chapters. The first chapter is the introduction and presents the problem, the motivation, the objectives, the expected results and the project work plan. The second chapter is the state of the art that describes the options for the construction of all the parts of the humidifier and our choices. The third chapter is the project development and presents the project architecture, the modules, the functionalities and the tests. The fourth chapter is the conclusion where the discussion and future developments of the project is presented. Finally, in the sixth chapter, the bibliography, we list the references of all sources of information used.

State of the Art

A humidifier is a household appliance that increases humidity (moisture) in a single room or in the entire house. In this case the humidifier will go moisten a data center with a view to a better functioning.

Type of humidifiers

Steam humidifier

Working method: It makes the vapor by heating the water above its boiling point, than distibute this steam in the room.
Advantage: fast, can make a big amount of vapor
Disadvantage: need lot of energy, heating the room

Fan humidifier

Working method: It contains a pot with water and a filter in it. That filter soak up the water. Above the filter there is a fan, what is moving the air of the room through the wet filter and the water vaporize in natural way.
Advantage: made from simple parts → less failure possibilities, not need complex control
Disadvantage: slow, also move the air too

High water pressure:

Working method: pressure pump supply water to the nozzles at between 50 bar - 70 bar. The nozzles are made for ceramic, opening 0,2 mm - 0,5 mm.
Advantage: no algae – high pressure, high performance, quiet work,
Disadvantage: high cost

Ultrasounds method:

Ultrasounds are made by piezoelectric cell. The sounds make water trembling. It makes very small drops of water.
Advantage: quiet work, very small drops
Disadvantage: algae, low performance-high energy consumption

Compress air method

Compress air is mix with water in special nozzle(pressure about 2 bar). Nozzle distribute water
Advantage: quiet work – if we use fridge compressor, quite cheap, quite simple
Disadvantage: algae

Control

To control the humidifier we found two solutions:

  • Micocrontroller
  • PLC

Microcontrollers are typically used in automation and control products and peripherals, as systems of automotive engine control, remote controls, residential and office machines, toys, surveillance systems. PLCs are based on microcontollers which allows solutions far economic.The current can be networked, often with private protocols of each manufacturer. It is increasingly common to use the Ethernet for connecting computers and PLC.

For our choice we made a small table with values ​​between 0 and 5 with important aspects for the project:

PLC Microcontroller
Life 5 3
Price 2 5
Programming 4 3
Similar Aplications 2 5
Total 13 16

The final decision is to use the microcontroller. The PLC is used in large industrial applications and therefore is more expensive but has a language programing easier. Because of this we chose the microcontroller programming despite being more difficult than the PLC.

Web Interface

The web interface will be developed with Java. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities. Java is currently one of the most popular programming languages in use, and is widely used from application software to web applications. For the interconnection of various parts of the web interface we will use the following software:

  • Tomcat
  • MySQL
  • Notepad ++

List of Material

After the research materials necessary for construction of the humidifier compiled a list of materials to buy:

(list of material)

All prices include IVA but not shopping costs

Project Development

Architecture

ar.jpg

Modules

  • Web interface
  • Container
  • Control and Electric Part
    • Control humidifier code
    • Control water tank code
    • Interconnection with Web interface
    • Electric Circuit
  • Humidifier
    • Compressor
    • Air tank
    • Nozzle
    • Water pump
    • Water tank

Functionalities and Developments

Humidifier

Datacenter humidity needs to be between 40 % - 70 %. For This we need of a humidifier.We have decided that we want to make compressed air humidifier. We thing it is the best connection of price and performance. This idea was changing. At first we wanted to make own compressor. We wanted to use fridge compressor. We have found working solution on the internet[3]. It was the cheapest option and the more quite but we aren’t sure it could work all the time and we weren’t sure off air pressure. Here is the graphic presents how we wanted to make it.

After that we decided to buy the complete compressor in the shop. It is the most expensive part in our project. The most important specification and photo:

Producer: ABAC

Name: Vento 2002

Volt: 230/240

Watt: 750

Max pressure [bar]:8

Silent: 66 dB

Capacity of the air tank [l]: 6

Dimensions [mm]: 530x210x540

Weight [kg]: 9

Photo:

More info:[1][4]

We also decide to use special nozzle for humidifier.

Producer: Isofluido’s Lechler Nozzle

Name: 136.330.35.16

*Q: [l/h]* 1,2 (4bar)

More info[2]

We also have bought the pump because we wanted to supply water to nozzle by the small container. schemat1.jpg.

It turned up that it is not necessary and makes also problems. The water from small tank drain very quickly by the nozzle. The water valve could resolve this problem but we have decided that we place the nozzle not far from big tank. In this case we don’t need any pump and any small container. We have made a test and it works. The air presser is enough to suck water from the box and we don’t have problem with licking.

It is very easy solution. Easier than we excepted. We have made a few tests and we know that this idea is good. We have very small drops of water. Higher level of pressure makes smaller drops of water.

The compressor can’t work all time and it has only small air tank so pressure decrease very quickly. The next thing what we have to consider is temperature of compressor. It is getting hotter very quickly and turn of. We need to set the time to open the electric valve. The correct cycle for the compressor is 2,5 min working and 7,5 min resting.

Control

The control will serve to communicate with the sensors, sensing the water level of the tank, control the switches for pump and electric valve. This control will be done with arduino with internet connection.

Construction program for the arduino

As the first step to building code we elaborate flowchart:

  • Control Humidifier and Web interface

  • Control water tank

The code will contain several parts as shown in the following diagram:

Web interface

The web interface will be the hardest part. It will identify the sensors and life-cycle analysis of the humidity and temperature. The web interface is the tool that people use to control humidifier.

In a first contact with the language we develop a small program to test the interconnection and compiling of software:

Water Tank

First we calculated that the 80m3 air how much water the air contains in the same temperature but in different percentage. After we made it for the all temperature what occured in the data center. Later by takeing these numbers into a table we could easily calculate how many water we need to raise the hummidity from one point to the other. Unfortunately the datacenters measurements has not enough changes and we could not make tests in the room, so we coudn't calculate the exact amount what we need for 2 days. Than we chose the tank to be enough for the worst case for two days.

Container

procet_v2.jpg

Markting Plan

Conclusions

Throughout these weeks the job was essentially to research and discussion. Initially we discussed the type of humidifier where we propose two options. The first option was using a humidifier cold type, through a nozzle, which should bring a compressor to supply compressed air and a water pump to provide water. The other option was to use a humidifier also cold, because hot type to use a humidifier too complicated and dangerous. The second option consists of a water tank which has a filter on top and a front fan, which means that there is an air circulation inside the tank and extract Humidity outward. In the end we opted for the first option, because the shape of the humidity injected in the room is much faster and instant.

The other discussion was to choose the type of control that we had to use because for the controll we found two options viables. One option was to use a small PLC, since these devices are designed for the industry and are very sturdy, its programming is also very easy, by GRAFCET. The other option was to use a microcontroller. It size is very limited and this makes it very easy to integrate it into the design of the humidifier, also these last devices are designed for this kind of small applications. The problem is that these last items are much more complicated to program the PLC. The final decision was the price of the items, since the PLC and cost over 300 € and the microcontroller costs about 60 €.

Future Developments

The next step in this humidifier should be system to remove water pollution. It could be chemical compound or UV lamp. The next developments could be finding the way to reduce a size and turn volume down. The next thing to do is container and structure. We don’t have enough time to make it from composite material structure and water container. The next thing to improve container is size. For data center is better when container is higher than widther. We can also add the pressure reducer to have the same pressure in the nozzle. It could make the same size of drops all time.

Bibliography

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