JP4062802B2 - Data communication system in boiler multi-can installation system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data communication system in a boiler multi-can installation system .
[0002]
[Prior art]
A boiler multi-can installation system is installed in which a plurality of boilers are installed in parallel, and the number of combustion of the boilers is controlled based on the pressure in a steam header common to each boiler. The boiler multi-can installation system is provided with a number control device that takes in a signal from a pressure sensor provided in the steam header and outputs a number control signal based on the steam pressure in the steam header. Each of the boilers is connected to the number control device via a communication line. Each boiler is also connected by a communication line, and a communication network is formed between the number control device and each boiler.
[0003]
[Problems to be solved by the invention]
A data communication system in a communication network in the boiler multi-can installation system is required to operate with high reliability and stability. There is also a demand for shortening the construction time of communication facilities and reducing construction costs.
[0004]
[Means for Solving the Problems]
The invention according to claim 1 is a plurality of boilers installed in parallel, each having a controller, a steam header connected to each of the boilers, a pressure sensor for detecting a steam pressure inside the steam header, In a data communication system in a boiler multi-can installation system comprising a number controller having a controller that outputs a number control signal to the boiler according to a preset program based on a signal from a pressure sensor, each controller is A wireless data communication means for performing data communication between the controllers by wireless communication; and a wired data communication means for performing data communication through a power line connected between the controllers , wherein the wireless data communication means is a contention system. And before transmitting data by the wireless data communication means, to the power line using the power line data communication means Output a busy signal to inform other controllers that transmission will be performed by wireless communication. The other controllers detect the busy signal, yield the right to use wireless data communication, and cause a collision of wireless data communication. It is characterized by being configured to avoid .
[0005]
According to a second aspect of the present invention, in the first aspect, each of the wireless communication means and each of the wired communication means has an output signal that is spread over a predetermined frequency region and an input signal that is spread over the predetermined frequency region A spread spectrum circuit that performs processing for restoring the original state, received data processed by the spread spectrum circuit of each wireless data communication means, and received data processed by the spread spectrum circuit of each wired data communication means, And a bit discriminating circuit for comparing at the bit level whether or not they are the same data .
[0006]
Invention of Claim 3 transmits the pressure information in the said steam header in the said Claim 1 or Claim 2 from the controller of the said number control apparatus to the controller of the said boiler by the said wireless data communication means, A number control signal based on the pressure in the steam header is transmitted by the power line data communication means .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A plurality of devices (industrial devices such as boilers) are installed, and each device is provided with a controller that controls the operation of the devices. Each controller includes both wireless data communication means and wired data communication means, and data communication between the controllers is performed by these communication means.
[0010]
In one embodiment, data communication is performed using both the wireless data communication unit and the wired data communication unit simultaneously. In that case, the controller compares the reception data by the wireless data communication unit and the reception data by the wired data communication unit, and outputs a control signal based on the comparison result. That is, if the two received data match, it is determined that the data is correct, and the next control operation is instructed. By doing so, the reliability of the received data is improved.
[0011]
In another embodiment, the wireless data communication unit and the wired data communication unit are selectively used in accordance with the type of data, the time zone, and the like, and are switched appropriately for use. For example, if there is a time zone in which a failure is likely to occur in the received data by the wireless data communication means depending on the operating conditions of the machines around the device, data communication by the wired data communication means is performed in that time zone. On the contrary, if there is a time zone in which the failure is likely to occur in the data received by the wired data communication means, data communication by the wireless data communication means is performed during that time zone.
[0012]
There may be a problem in the wireless data communication means due to the appearance of an electromagnetic shield or the like, or a problem in the wired data communication means due to an increase in noise or the like, making it impossible to communicate correct data. In that case, the communication by the communication means in which the malfunction has occurred is stopped, and the communication is switched to the communication by only the other normal communication means. By doing so, the device can be continuously operated without stopping. At that time, the safety is further improved by increasing the redundancy of data to be transmitted or by narrowing the operating range of the device to the safe side.
[0013]
As the wired data communication means, normal communication means (RS-232C, optical communication, etc.) can be used, and power line data communication means can also be used. When the power line data communication means is used, both the supply of electricity as power and the data communication can be performed by the power line, and there is no need to separately provide the communication line.
[0014]
According to the above-described configuration, it is possible to provide a reliable and stable data communication system using the wireless data communication unit and the wired data communication unit. Further, by using the wireless communication means, or by using the power line data communication means as the wired data communication means, it is not necessary to specially attach wiring for communication, and the construction time of communication equipment can be shortened. Construction cost can be reduced.
[0015]
【Example】
Hereinafter, an embodiment in which the present invention is applied to a boiler multi-can installation system will be described with reference to the drawings. In FIG. 1, a plurality of boilers 1 are installed in parallel, and each boiler 1 is connected to a steam header 4 by a steam pipe 3 provided with a steam valve 2. The steam collected in the steam header 4 from the boiler 1 is sent to each steam using device (not shown).
[0016]
The steam header 4 is provided with a pressure sensor 5 for detecting the internal steam pressure. The pressure sensor 5 is connected to the number control device 6. The number control device 6 outputs a number control signal to the boiler 1 according to a preset program based on the signal from the pressure sensor 5. Combustion and stop of each boiler 1 are controlled by this number control signal.
[0017]
In the above embodiment, the boiler 1 and the number control device 6 correspond to the devices in the present invention, and the controller 7 of each device has wireless data communication means A and wired data for performing data communication between the controllers 7. Communication means B is provided. In the illustrated embodiment, the terminal in the boiler 1 is integrally formed in the controller 7, but may be configured separately.
[0018]
The wireless data communication means A includes an antenna 8 and transmits and receives data by wireless communication. In the illustrated embodiment, the wired data communication means B uses power line data communication means, and performs both supply of electricity as power and data communication by the power line 9 connected between the controllers 7. It is like that.
[0019]
FIG. 2 shows an example of the configuration of the controller 7. The controller 7 includes a microprocessor 10 and a control input / output interface 11. The microprocessor 10 performs various arithmetic processes. For example, a signal from each accessory device (water level detector, flame detector, pressure detector, etc.) of the boiler 1 is input to the control input / output interface 11, and each accessory device ( A control signal is output to a fuel supply valve, a feed water pump, and the like. Both the wireless data communication means A and the wired data communication means B employ a spread spectrum system to improve noise resistance. Both the communication means A and B are connected to the microprocessor 10.
[0020]
The wireless data communication means A includes a spread spectrum circuit 12, a frequency conversion circuit 13, and an antenna 8. The wired data communication means B includes a spread spectrum circuit 12, a frequency conversion circuit 13, and a power line coupling circuit 14. For example, the spread spectrum circuit 12 multiplies transmission data by a PN (pseudo-noise) code to widen the output signal to a predetermined frequency region, or restores the input signal expanded to the predetermined frequency region to the original state. Make. The frequency conversion circuit 13 converts the output signal into a predetermined frequency signal for communication, and converts the received frequency signal into a predetermined input signal. The power line coupling circuit 14 is connected to the power line 9 and transmits communication data to the power line 9 or receives communication data from the power line 9.
[0021]
A power supply circuit 15 that supplies electricity to the power line 9 is connected to the power line 9. Further, the controller 7 is provided with a bit discrimination circuit 16, and this bit discrimination circuit 16 is connected to the microprocessor 10, the wireless data communication means A, and the wired data communication means B. The bit discriminating circuit 16 performs comparison judgment at the bit level of received data, which will be described later.
[0022]
Next, a specific data communication method will be described. The wireless data communication unit A and the wired data communication unit B transmit data that is a common calculation result. For example, pressure information in the steam header 4 is transmitted from the controller 7 of the number control device 6 to the controller 7 of the boiler 1 by the wireless data communication means A, and the steam header 4 is transmitted by the power line data communication means. A unit control signal based on the internal pressure is transmitted. Since this number control signal is based on the calculation result based on the pressure information in the steam header 4 in the controller 7 of the number control device 6, the calculation based on the same pressure information is also performed by the controller 7 of the boiler 1. And determine whether the calculation results match.
[0023]
In this way, the controller 7 of the boiler 1 determines the consistency of the data received by the communication means A and B, and controls the combustion and stoppage of the boiler 1. That is, the controller 7 compares the data received by the wireless data communication unit A and the data received by the wired data communication unit B, and if the calculation results of both received data match, the received data is correct. And a control signal based on the received data is output.
[0024]
The wireless data communication means A and the wired data communication means B transmit data of the same bit string, and the controller 7 that receives the data secures synchronization while correcting the time difference by the bit discrimination circuit 16. In addition, it is possible to compare and determine at the bit level whether the data is the same.
[0025]
The wireless data communication unit A and the wired data communication unit B are configured to perform basic error control such as error detection / retransmission control (detects an error in received data and retransmits the same data when an error is detected). It has a function, and a normal error in data communication is corrected by this basic error control function. However, an unexpected situation occurs, for example, an electromagnetic shielding object is placed near the antenna 8 and accurate data cannot be communicated by the wireless data communication means A. When it becomes impossible to communicate accurate data with the communication means B, the communication by the communication means in which the malfunction has occurred is stopped, and the communication is switched to the communication by only the other normal communication means. And it is made to drive | operate continuously, without stopping apparatuses, such as the said boiler 1 and the said number control apparatus 6. FIG.
[0026]
At that time, the error is increased by adding an error correction code to the data to be transmitted, or the numerical level for failure determination in the boiler 1 is changed to the safe side, so that the safety is further improved. .
[0027]
Further, other application examples will be described. In the wireless data communication means A adopting the contention method, if there are controllers 7 that cannot detect each other whether or not they are in a communication state (cannot carry out carrier sense), a collision of communication increases and communication efficiency decreases. Therefore, the wired data communication means (power line data communication means) B is used to output a busy signal to the power line 9 before transmitting the data by the wireless data communication means A and to transmit to the other controller 7 by wireless communication. Tell them to do it. The other controller 7 detects this busy signal, yields the right to use wireless data communication, and avoids collision of wireless data communication. The busy signal is continuously generated during wireless communication. Further, when the necessity of urgent data communication occurs, even if another controller 7 is transmitting, the JAM signal is superimposed on the busy signal of the power line 9 so that the controller 7 that is transmitting Notify the generation of data and take over the transmission right.
[0028]
The wired data communication means (power line data communication means) B cannot transmit data to the controller 7 connected to another system communication line (power line 9). Therefore, the wireless data communication means A is used to perform data communication between different systems using the controller 7 provided with the wireless data communication means A and the wired data communication means B without newly providing a communication line. To.
[0029]
【The invention's effect】
According to the present invention, by using the wireless data communication unit and the wired data communication unit, it is possible to prevent a decrease in communication efficiency due to an increase in communication collision, and it is possible to increase the number of boilers that can perform a reliable and stable number control operation. A data communication system in a can installation system can be provided .
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment in which the present invention is applied to a boiler multi-can installation system.
FIG. 2 is an explanatory diagram showing a configuration of a controller in FIG. 1;
[Explanation of symbols]
7 Controller 9 Power line A Wireless data communication means B Wired data communication means

Claims (3)

A plurality of boilers 1 installed in parallel, each having a controller 7, a steam header 4 connected to each of the boilers 1, a pressure sensor 5 for detecting the steam pressure inside the steam header 4, and the pressure sensor 5 In a data communication system in a boiler multi-can installation system comprising a number controller 6 having a controller 7 that outputs a number control signal to the boiler 1 according to a preset program based on a signal from
Wherein each control unit 7, a wireless data communication means A for performing data communication between the controllers 7 by wireless communication, wired communication unit B to perform data communication by a power line 9, wherein connected between the controller 7 Prepared ,
The wireless data communication means A is a contention system,
Before transmitting data by the wireless data communication means A, the power line data communication means B is used to output a busy signal to the power line 9 to inform the other controller 7 that it will be transmitted by wireless communication from now on,
The other controller 7 detects the busy signal, yields the right to use the wireless data communication, and avoids the collision of the wireless data communication . The data communication system in the multi-can installation system for the boiler, . Each of the wireless communication means A and the wired communication means B has a spread spectrum circuit that performs processing for expanding the output signal to a predetermined frequency region and returning the input signal expanded to the predetermined frequency region to the original state. 12 and whether the received data processed by the spread spectrum circuit 12 of each wireless data communication means A and the received data processed by the spread spectrum circuit 12 of each wired data communication means B are the same data A data communication system in a boiler multi-can installation system according to claim 1, further comprising a bit discrimination circuit (16) for comparing and judging by level . Pressure information in the steam header 4 is transmitted from the controller 7 of the number control device 6 to the controller 7 of the boiler 1 by the wireless data communication means A, and in the steam header 4 by the power line data communication means B. A data communication system in a boiler multi-can installation system according to claim 1 or 2 , wherein a unit control signal based on the pressure of the boiler is transmitted .

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