Enhance of house heating control by using of LabView.

Gordan, Mircea ; Gordan, Cornelia ; Pop, Adrian Petru 等

1. INTRODUCTION

The paper presents a solution for heating optimization of a house with two levels and six rooms on every level. The heating is developed by a central heating installation using type M-fuel. The heating central installation has also a boiler of capacity-120 l (Fig.1) for the warm water of domestic use. The central heating installation is made in Italy.

The heating installation contains a central vertical colon, which has radial branches at every level. This way of thermal losses is very low.

As it was mentioned above the central heating installation has two functions: produces the thermal agent for the heating and the warm water needed for domestic use.

For the heating process, the central heating installation is used six months a year: from the middle of October to the middle of April. In the other six months of the year, it is used only for the warm domestic water. The quantity of fuel need for the whole year is about 3700 1.

The temperature inside the rooms is controlled with two electronic thermometers, each one being placed at different level in a room, considered as being the reference.

During winter, the medium temperature inside the house is around of 24[degrees]C, but it has not the same values everywere.

2. MODULE FP-1000

The network module Field Point FP-1000 has an industrial network connector RS-232, used to interconnect the I/O Field Point module to the computer.

This connector supports the standard commands and a group of extended commands used to complete the I/O Field Point modules support (Handbook HP-1000, 1998)

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The module FP-1000 uses Optomux protocol. After finishing the configuration process of Field Point banc (network and I/O modules), can be used any program which supports the Optomux connections, for the communication of Field Point modules inside the banc.

On every RS-232 port can be connected just one FP-1000 network module from computer. In order to connect a few Field Point modules on the computer, without using more then one RS-232 ports can be connected one or more FP-1001 (1 / 24) network modules to the RS-185 receiving port from the FP-1000 module. The configuration of this network is the one from Fig. 2 (Handbook HP, 1998; Gordan et al., 2003).

The RS-232 port from the FP-1000 network module can develop a communication in both ways. The RS-485 port from the FP-1000 network modules is optic isolated and can also develop a communication in both ways.

The transfer speed can be: 300; 1200; 2400; 9600; 19200; 38400; 57600; and 115200 baud. On the network module are placed the buttons used to set up the transfer speed. In Fig. 3 are presented the 8 possible positions of the switch from the FP-1000 Field Point network module. Switches 1-5 set the network addresses and switches 6-8 set the transfer rate in "baud" (Gordan a, b, 2003; Isar et al., 2002).

The FP-1000 network module can detect any unpredicted period of pause in the network activity and response to this situation in a way defined by the user.

The characteristic of sequence controller is that survives the system and observes a disconnecting of the network, cable or computer. Also, this controller imposes the defined state for the exit channel, if this state does not already exists.

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3. HEATING PROCESS OPTIMIZATION

The computer was placed in a room from the first level, so that the connection to the FP-1000 modules to be the minimum ([approximately equal to] 4 m). For this purpose were used two modules FP-1000, one for analogical output (24) and for the analogical input (24). On the computer was installed the LabVIEW 6.0 program.

The connection between the FP-1000 modules and the central heating installation was developed using the electronic-command side of the central heating installation.

In the three most important rooms from every level were placed resistive transducers, made by Siemmens, who are compatible with the FP-1000 modules.

In order to simplify the temperature control inside the rooms and the control of the central heating installation were developed a few animated control windows (Fig.4).

In the animated control windows is presented the temperature values by the three transducers placed at the same level, the fuel consumption, outside temperature, thermal agent temperature and domestic hot water temperature.

The fuel consumption can be presented in different ways: the instantaneous consumption; total consumption for 24 hours; the consumption for a week, etc.

The transducer for the flow of the fuel is also Siemmens made and is compatible with the FP-1000 module.

As a result of this optimization process the fuel consumption for one year was smaller (decreased to 2600 1 h 2700 l) for the entire house (both levels).

The program for watch-dog, control and driving took also into account the different levels of the outside temperature during a day:

--the temperature in the house must be bigger at the first hours in the morning (between 6.30 h 8.00); also this temperature must be lower from morning until the afternoon when the families is not home;

--the temperature must grow in the afternoon and during the evening and must be smaller in the night time.

Also must be mentioned that the temperatures by the three rooms from one level were different.

The disadvantages of this system of watch-dog, control and driving are:

--the price is relative height: [approximately equal to] 7500 $ (FP--1000 modules, temperature transducers, flow transducer, the computer, the program LabVIEW, connecting cables, etc.);

--the system depends on the national power network; from this reason it must have an independent power supply which must sustain the system (from electrical point of view) when the national power network falls.

--the house must be thermo-insulation, which doing of improving optimization system.

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In Fig.5 is presented the scheme developed in LabVIEW for the windows described above.

The advantages of this system of control are:

--a smaller quantity of fuel consumed;

--a particular control of the temperature inside the rooms in time;

--the possibility of an easy changing the temperature levels inside the rooms during a specified interval of time (this interval can be programed);

--the electric power consumed is very low.

This solution represents a biggner, today the acquisition systems of Field Point became more performance and low cost.

As an experience get in time, the program can be enhance continuu, having advantage of rising reaction speed of watching control system. In addition, the system can be endow with an auxiliary source, which has the role of keeping system in working each at damage of power system, situations usually met in winter time.

4. CONCLUSION

The paper has presented a solution for improving the control of house heating by using LabView Program.

The heating installation used at house with two levels was ASTON MASTER B 120 from Italy. By using Field Point FP- 1000 module and a computer with LabVIEW programme has obtaind enhance of heating system control such as: control of tempeature inside of room in time, reducing fuel consumption with 1000 l/year and the power consumed.

All of these advantages justified in final the investion in this control of heating installation used at house.

5. REFERENCES

Gordan, M; Tomse, M; Mich, C & Viktor, F. (2003). Electrical

measuements and measure systems, Univ. of Oradea Editor, Oradea

Gordan, M. (2003). Installations of measurement and control,

Univ. of Oradea Editor, Oradea Gordan, M. (2003). Electrical measurements in electrotechnics,

Univ. of Oradea Editor, Oradea Isar, A., Gordan, C. & Nafornita I. (2002). Signals and sistems,

Orizonturi Studentesti Editor, Timisoara

*** (1998). Handbook of FP-1000, National Instruments.