JPH08159554A - Device for automatically controlling number of thermal medium boilers - Google Patents

Abstract

PURPOSE: To improve a characteristic of follow-up for a variation in load in a thermal medium boiler and to prevent a loss of thermal energy. CONSTITUTION: A device for controlling the number of thermal medium boilers 1 for their operation in response to a temperature sensing signal obtained from a temperature sensor 8 under an arrangement in which a plurality of thermal medium boilers 1 are arranged in parallel to each other, outlet pipes 2 and return pipes 3 of these thermal medium boilers 1 are connected to each of a going header 4 and a return header 5 which are common to each of the thermal medium boilers 1, respectively, the going header 4 and the return header 5 are connected by a circulation line 7 having a load machine 6 inserted therein, either one of the going header 4 and the return header 5 is provided with the temperature sensor 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat medium boiler automatic number controller for installing a plurality of heat medium boilers in parallel and automatically controlling the number of operating heat medium boilers according to the load condition. It is a thing.

[0002]

2. Description of the Related Art A so-called heat medium boiler for heating a heat medium in a boiler and supplying and circulating the heat medium to a load machine is well known. Usually, as the temperature control method of the load machine, a temperature control valve is provided in the heat medium circulation line to adjust the circulation flow rate of the heat medium according to the temperature of the heat medium.
When the heat capacity of the load machine is large and the load fluctuation range is large (for example, fluctuation of 0 to 100%), the temperature of the heat medium supplied to the load machine cannot be controlled to be constant and cannot follow the load fluctuation. There is. For example, when the temperature of the heat medium rises too much, the circulating flow rate is reduced, but due to the problem of overheating in the heat medium boiler, it cannot be reduced to below the minimum required flow rate. However, if the operation is stopped once, a response delay occurs when the heat request is made again.

Further, when a plurality of load machines are installed, the capacity of the heat medium boiler is selected so as to be able to supply the heat quantity when all the load machines operate.
When all the load machines do not operate at the same time, only wasteful heat is circulated and heat energy is lost.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the followability to load fluctuations and prevent the loss of thermal energy in a heat medium boiler.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, in which a plurality of heat medium boilers having a relatively small capacity are installed in place of one large capacity heat medium boiler. That is, a plurality of heat medium boilers are installed in parallel, and the outlet pipe and the return pipe of these heat medium boilers are connected to the forward header and the return header common to each heat medium boiler, respectively.
The forward header and the return header are connected by a circulation line in which a load machine is inserted, and a temperature detector is provided on one of the forward header and the return header, based on a temperature detection signal from the temperature detector. And a unit number control device for controlling the number of operating heat medium boilers.

[0006]

[Function] Based on the temperature detection signal from the temperature detector provided on the forward header or the return header, the number of operating heat medium boilers is reduced when the temperature of the heat medium is high, and the heat medium is low when the temperature of the heat medium is low. Increase the number of boilers in operation to quickly respond to changes in the required heat quantity of the load machine.

[0007]

The preferred embodiments of the present invention will be described below. In FIG. 1, a heat medium boiler 1 having heating means
Multiple heat exchangers are installed in parallel, and the outlet pipe 2 of these heat medium boilers is installed.
The return pipe 3 is connected to the forward header 4 and the return header 5 common to each heat medium boiler 1. The forward header 4 and the return header 5 are connected by a circulation line 7 formed by inserting a load machine 6 and a circulation pump 10. The forward header 4 is provided with a temperature detector 8 for detecting the temperature of the heat medium in the header. This temperature detector 8 can also be provided in the return header 5 depending on the implementation. The temperature detector 8 is connected to the unit number control device 9 by a signal line, and the unit number control device 9 determines the operating number of the heat medium boiler 1 based on the temperature detection signal from the temperature detector 8. It is designed to be controlled. When the temperature of the heat medium becomes high, the number of operating heat medium boilers 1 is reduced, and when the temperature of the heat medium becomes low, the number of operating heat medium boilers 1 is increased.

FIG. 2 shows the relationship between the heat medium temperature in the forward header 4 or the return header 5 and the number of operating heat medium boilers 1. The case where four heat medium boilers 1 are installed is illustrated. The temperature control range (L to H) of the heat medium is set to the heat medium boiler 1
The number of installed N-1 (4-1 = 3) is divided into approximately equal parts,
Each division point is a switching point for the number of operating heat medium boilers 1. For example, the upper limit value H of the temperature control range is 300 ° C.,
If the lower limit value L is set to 240 ° C, 240 ° C, 260
℃, 280 ℃, 300 ℃ is the switching point of the number of operating respectively. That is, when the temperature T of the heat medium detected by the temperature detector 8 exceeds the upper limit value H (300 ° C.) of the temperature control range, all the heat medium boilers 1 are stopped and the detected temperature T is within the temperature control range. When the temperature is below the lower limit value L (240 ° C) of, all the heat medium boilers 1 are operated,
It is set so that the number of operating machines is three at 240 to 260 ° C, two at 260 to 280 ° C, and one at 280 to 300 ° C. These unit control programs are set by setting the upper limit value H and the lower limit value L of the temperature control range,
Further, it can be automatically set by inputting three values of the number N of the heat medium boilers 1 installed.

Next, the operation of the above configuration will be described. The heat medium heated by the heat medium boiler 1 passes through the outlet pipes 2 and collects in the outgoing header 4, and is supplied from the outgoing header 4 to the load machine 6 through the circulation line 7. The heat medium that has supplied a predetermined amount of heat to the load machine 6 returns to the return header 5 through the circulation line 7, and returns from the return header 5 to the heat medium boiler 1 through each return pipe 3. Temperature detector 8 provided on the forward header 4 (or the return header 5)
A heat medium temperature detection signal is sent to the unit number control device 9.
Receiving the temperature detection signal, the number-of-units control device 9 controls the number of operating heat medium boilers according to the temperature of the heat medium according to a preset program (see FIG. 2). By controlling the operating number of a plurality of heat medium boilers 1 installed in parallel, the followability with respect to load fluctuation is improved, and unnecessary heat medium boilers are not operated, so that loss of heat energy is prevented.

By providing the forward header 4 to collect the heat medium at one place and detecting the temperature of the heat medium in the forward header 4, the temperature difference of the heat medium from each heat medium boiler 1 is averaged,
An accurate value of the temperature of the heating medium supplied to the load machine 6 can be detected, and the number of operating heating medium boilers 1 can be controlled accurately with respect to changes in the load. Further, even when the return header 5 is provided with a temperature detector, the heat medium can be returned to the heat medium boilers evenly from the return header 5, and the return flow rate and the return temperature of the heat medium can be made uniform in each heat medium boiler. Therefore, the number of operating heat medium boilers 1 can be controlled accurately with respect to changes in load. In the heat medium boiler, the temperature control range is 240 as described above.
Since the temperature is relatively wide at up to 300 ° C., such a configuration is highly effective in improving followability with respect to load fluctuations.

The circulation flow rate by the circulation pump 10 can be constant, but can be adjusted at any time according to the heat demand (heat medium temperature) of the load machine 6. In that case, the control of the circulating flow rate of the heat medium and the control of the number of operating heat medium boilers of the present invention are combined. Further, the circulation flow rate may be controlled by providing a temperature control valve and a bypass line.

Further, the heat medium boiler 1 is set to be operated according to a preset priority order, but in order to average the operating time of each heat medium boiler 1, rotation of the priority order is appropriately performed. I am trying.

[0013]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned configuration, by controlling the operating number of a plurality of heat medium boilers provided in parallel, the followability to load fluctuation is significantly improved and unnecessary. Since a heat medium boiler is not operated, loss of heat energy is prevented, which has a great effect on energy saving. Also, because the configuration is to detect the temperature of the heat medium in the forward header or the return header to control the number of operating units, the temperature difference of the heat medium is averaged and the accurate value of the temperature of the heat medium supplied to the load machine is detected. This makes it possible to control the number of operating heat medium boilers accurately with respect to changes in load, and is highly effective in improving followability with respect to changes in load. Further, the setting of the number control program can be automatically set by inputting the three values of the upper limit value H and the lower limit value L of the temperature control range, and the number N of heat medium boilers installed, which is practical. It is very effective.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing an example of the relationship between the heat medium temperature and the number of operating units in the present invention.

[Explanation of symbols]

 1 Heat Medium Boiler 2 Outlet Pipe 3 Return Pipe 4 Outgoing Header 5 Return Header 6 Load Machine 7 Circulation Line 8 Temperature Detector 9 Unit Control Device

Claims (2)

[Claims] 1. A plurality of heat medium boilers 1 are installed in parallel,
The outlet pipe 2 and the return pipe 3 of these heat medium boilers 1 are connected to a forward header 4 and a return header 5 common to the respective heat medium boilers 1, and the forward header 4 and the return header 5 are inserted with a load machine 6. A temperature detector 8 is provided on either one of the forward header 4 and the return header 5 which are connected by a circulating line 7 which is provided. Based on a temperature detection signal from the temperature detector 8, the heat medium boiler 1 An automatic controller for controlling the number of heating medium boilers, comprising a controller for controlling the number of operating machines 9. 2. The automatic number control device for a heat medium boiler according to claim 1, wherein the number control device 9 sets the temperature control range (L to H) of the heat medium to the number N− of the heat medium boilers 1 to be installed.
When the temperature T of the heat medium detected by the temperature detector 8 exceeds the upper limit value H of the temperature control range, heat is generated when the temperature detector 8 switches the number of operating heat medium boilers 1 at each division point. An automatic number controller for heat medium boilers having a function of stopping all of the heat medium boilers 1 and operating all of the heat medium boilers 1 when the detected temperature T falls below a lower limit value L of the temperature control range. .