JPH0719599A - Combustion controlling method for heating medium boiler - Google Patents

Abstract

PURPOSE:To provide a combustion controlling method for a heating medium boiler wherein an adequate combustion controlling can be executed, in response to a change of a load conditions with accuracy and rapidity. CONSTITUTION:A first temperature sensor 6 detecting a heating medium temperature at a boiler inlet section and a second sensor 7 detecting a heating medium temperature at a boiler outlet section are equipped, a plurality of temperature regions are preliminarily set against a detected temperature of a heating medium are arranged, and combustion conditions of a burner 4 are controlled on the basis of a combination of a temperature region wherein a heating medium temperature of a boiler inlet section detected by the first temperature sensor 6 is included and a temperature region wherein a heating medium temperature of the boiler outlet section detected by the second temperature sensor 7 is included.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a combustion control method in a heat medium boiler.

[0002]

2. Description of the Related Art In a conventional heat medium boiler, ON / OFF of a burner is controlled based on the temperature of the heat medium at the outlet of the boiler. Since it is the heat medium temperature after heating with the burner, a response delay will inevitably occur if there is a change in the amount of heat used in the load. Therefore, it is not possible to adequately perform appropriate combustion control according to changes in the load situation, and insufficient heating or excessive heating of the heat medium occurs.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a combustion control method for a heat medium boiler, which can accurately and quickly respond to changes in the load condition and can perform appropriate combustion control. .

[0004]

The present invention has been made in view of the above-mentioned problems, and a burner for heating a heat medium in the heat medium circulation line is provided with a heat medium circulation line in which a circulation pump is inserted. , A heat medium boiler equipped with a blower for supplying combustion air to the burner is provided with a first temperature sensor for detecting a heat medium temperature at a boiler inlet and a second temperature sensor for detecting a heat medium temperature at a boiler outlet. , A plurality of temperature regions are set in advance for the detected temperature of the heat medium, and the temperature region in which the heat medium temperature of the boiler inlet part by the first temperature sensor is included, and the heat medium of the boiler outlet part by the second temperature sensor are included. The combustion state of the burner is controlled based on a combination with a temperature range in which the temperature is included.

[0005]

Function: A plurality of temperature regions are set in advance for the detected temperature of the heat medium, the first temperature sensor determines which temperature region the heat medium temperature at the boiler inlet portion falls within, and the second temperature sensor detects the boiler temperature. It is determined in which temperature range the temperature of the heat medium at the outlet is included, and a control signal for controlling the combustion state is output to the burner based on the combination of these temperature ranges.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a heat medium boiler system to which the present invention is applied. A heat medium circulation line (3) is attached to the heat medium boiler (1). Further, the heat medium boiler (1) includes a burner (4) for heating the heat medium in the heat medium circulation line (3) and a blower (5) for supplying combustion air to the burner. The heat medium circulation line (3) is
A circulation pump (2) for circulating the heat medium is provided between the heat medium boiler (1) and a load (not shown) to circulate the heat medium, and in the heat medium circulation line (3). Has been inserted.
Normally, the circulation amount of the heat medium by the circulation pump (2) is set to be almost constant. (8) is the expansion tank unit, (9)
Indicates a storage tank unit, and (10) indicates a filling pump unit.

The heat medium circulation line (3) has a first temperature sensor for detecting the heat medium temperature at the boiler inlet, at the boiler inlet.
(6) and a second temperature sensor (7) for detecting the temperature of the heat medium at the boiler outlet are provided at the boiler outlet. The burner (4) operates based on the heat medium temperature detection signals from the first temperature sensor (6) and the second temperature sensor (7). The heating of the burner (4) maintains the temperature of the heating medium at a predetermined value. Further, the heat medium circulation line (3) is provided with a differential pressure detector (11) for detecting a difference between the pressure of the heat medium at the inlet of the boiler and the pressure of the heat medium at the outlet of the boiler. When the difference between the pressure of the heating medium at the boiler inlet and the pressure of the heating medium at the boiler outlet due to this differential pressure detector (11) is larger than a preset value, that is, the circulation pump (2) operates normally. When it operates and there is a circulation flow rate above a predetermined value, it is possible to shift to combustion. This is because there is a risk of overheating the heat medium when the circulation flow rate decreases due to a failure of the circulation pump, and so when the pressure difference is smaller than a preset value, do not shift to combustion. When the pressure difference becomes smaller than a preset value during combustion, the combustion is stopped.

As shown in FIG. 2, a plurality of temperature regions are preset for the detected temperature of the heat medium. In the embodiment shown in the figure, three regions A, B, and C are set in order of increasing temperature. These temperature regions are set by two numerical values, a high set temperature (TH) and a low set temperature (TL). That is, the area A is a temperature area above the high set temperature (TH), the area B is a temperature area between the low set temperature (TL) and the high set temperature (TH), and the area C is a temperature area below the low set temperature (TL). It is set. In addition, high set temperature (T
H) for high setting side differential (ΔTH)
However, the low setting side differential (ΔTL) is set for the low setting temperature (TL).

FIG. 3 shows the burner (4) based on the combination of the heat medium temperature at the boiler outlet and the heat medium temperature at the boiler inlet.
5 is a determination table of a combustion control signal output to. Stop,
Examples of three-position control for controlling three combustion states of low combustion and high combustion and two-position control for controlling two combustion states of stop and combustion are shown. The temperature range of the heat medium temperature at the boiler outlet is three, A, B and C, and the temperature range of the heat medium at the boiler inlet is also three, A, B and C. There are nine combinations in total. Which combustion control signal is to be output is preset for each combination.

The operation of the present invention will be described below with reference to the above embodiment. A circulation pump is installed in the heat medium circulation line (3) attached between the heat medium boiler (1) and the load (not shown).
The heat medium circulates due to the operation of (2). The circulation flow rate of the heat medium is set to be substantially constant. The heat medium circulation line
The heat medium in (3) is heated by the burner (4) of the heat medium boiler (1). The operation of the burner (4) is controlled so that the temperature of the heat medium is maintained at a predetermined value.

First, the heat medium temperature at the boiler inlet is detected by the first temperature sensor (6), the heat medium temperature at the boiler outlet is detected by the second temperature sensor (7), and the heat at these boiler inlets is detected. It is determined which preset temperature range the medium temperature and the heating medium temperature at the boiler outlet part fall within. As a result of this determination, the combustion state of the burner is determined according to the table shown in FIG. 3 based on the combination of the temperature range including the heat medium temperature at the boiler inlet and the temperature range including the heat medium temperature at the boiler outlet. To be done. Then, a control signal for controlling the combustion state of the burner is output from the control device to the burner and the blower.

For example, in the case of a heat medium boiler that employs three-position control for controlling three combustion states of stop, low combustion, and high combustion, the heat medium temperature at the boiler outlet is in the region B, and the heat at the boiler inlet is If the medium temperature is in the C range, a high combustion signal is output. In addition, the heating medium temperature at the boiler outlet is in the area A,
If the heating medium temperature at the boiler inlet is in the region B, a control signal for starting only purging (supply of combustion air by the blower) is output.

Further, based on the signal from the differential pressure detector (11), when the difference between the pressure of the heat medium at the boiler inlet and the pressure of the heat medium at the boiler outlet is larger than a preset value, that is, When the circulation pump (2) operates normally and there is a circulation flow rate equal to or higher than a predetermined value, the flow is shifted to combustion, and when the pressure difference becomes smaller than a preset value during combustion, the combustion is stopped. However, since the viscosity of the heating medium changes depending on the temperature, there is a difference between the startup operation and the steady operation of the boiler.
Even if the flow rate of the heat medium is the same, the pressure difference between the boiler inlet part and the boiler outlet part is different. Therefore, if an appropriate pressure difference setting value is not selected, even if combustion can be started during startup operation, the viscosity of the heating medium decreases during steady operation and the pressure difference decreases, and combustion is required. It may not be possible to carry out combustion. Therefore, in the present invention, the difference between the heat medium temperature at the boiler inlet detected by the first temperature sensor (6) and the heat medium temperature at the boiler outlet detected by the second temperature sensor (7) is set to a preset value. By comparison, it is checked whether or not the comparison result with the above-mentioned pressure difference matches.

If each device is operating normally, the comparison result regarding the temperature difference and the comparison result regarding the pressure difference match. That is, if the circulation flow rate of the heating medium is a predetermined value or more,
The difference between the pressure of the heat medium at the boiler inlet and the pressure of the heat medium at the boiler outlet is larger than the preset value, and the difference between the heat medium temperature at the boiler inlet and the heat medium temperature at the boiler outlet is also preset. Greater than value. Also, when an abnormality such as a failure of the circulation pump occurs and the circulating flow rate of the heat medium decreases, the difference between the pressure of the heat medium at the boiler inlet and the pressure of the heat medium at the boiler outlet is smaller than the preset value. Therefore, the difference between the heat medium temperature at the boiler inlet and the heat medium temperature at the boiler outlet becomes smaller than the preset value. Therefore, if the comparison results do not match, there is some abnormality in the system, and a signal to that effect is output to notify the boiler manager.

For example, the difference between the pressure of the heat medium at the inlet of the boiler and the pressure of the heat medium at the outlet of the boiler is smaller than a preset value, and the heat medium temperature at the boiler inlet and the heat medium temperature at the boiler outlet are If the difference is larger than the preset value, it is possible that the set value of the differential pressure detector is set incorrectly or the differential pressure detector itself is out of order. In such a case, while outputting a signal indicating that an abnormality has occurred, the operation of the heat medium boiler is not stopped, and it is judged whether the circulating flow rate of the heat medium is normal or not by the temperature difference instead of the pressure difference. By substituting for the determination in step 1, the operation of the heat medium boiler can be continued.

[0016]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned structure, it is possible to perform appropriate combustion control accurately and promptly in response to changes in the load condition. Therefore, there is no insufficient heating or excessive heating of the heat medium, and it is possible to maintain the heat medium at a predetermined temperature and supply a stable amount of heat. Further, by checking whether or not the comparison result regarding the temperature difference and the comparison result regarding the pressure difference match, it is possible to detect an abnormality or the like of the differential pressure detector.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a heat medium boiler system to which the present invention is applied.

FIG. 2 is an explanatory diagram regarding an embodiment of a set temperature region of the present invention.

FIG. 3 is an explanatory diagram regarding an embodiment of a combination of temperature regions of the present invention.

[Explanation of symbols]

 1 Heat Medium Boiler 2 Circulation Pump 3 Heat Medium Circulation Line 4 Burner 5 Blower 6 First Temperature Sensor 7 Second Temperature Sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Watanabe 7 Horie-cho, Matsuyama-shi, Ehime Miura Kogyo Co., Ltd. (72) Inventor Yasuo Tanouchi 7 Horie-cho, Matsuyama-shi, Ehime Miura Kogyo Co., Ltd. (72) Inventor Kei Shigematsu 7 Horie-cho, Matsuyama-shi, Ehime Miura Industrial Co., Ltd.

Claims (2)

[Claims] 1. A heat medium circulation line (3) having a circulation pump (2) inserted therein, a burner (4) for heating the heat medium in this heat medium circulation line, and a combustion air supply to this burner. In a heat medium boiler (1) equipped with a blower (5), a first temperature sensor (6) for detecting the heat medium temperature at the boiler inlet and a second temperature sensor (7) for detecting the heat medium temperature at the boiler outlet. And a plurality of temperature regions are set in advance for the detected temperature of the heat medium, and a temperature region in which the heat medium temperature of the boiler inlet portion by the first temperature sensor (6) is included, and the second temperature sensor (7 (3) A combustion control method for a heat medium boiler, characterized in that the combustion state of the burner (4) is controlled based on a combination with a temperature range including the heat medium temperature at the boiler outlet. 2. The combustion control method for a heat medium boiler according to claim 1, wherein the difference between the heat medium temperature at the boiler inlet and the heat medium temperature at the boiler outlet is compared with a preset value, and the boiler inlet is also used. Combustion of the heat medium boiler characterized by comparing the difference between the heat medium pressure of the section and the heat medium pressure of the boiler outlet with a preset value, and when the comparison result of the two is different, a signal to that effect is output. Control method.