JP2017048974A - Heating medium boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating medium boiler capable of precisely calculating a necessary combustion amount and, thereby, optimizing a heat supply amount to a heat using part.SOLUTION: A heating medium boiler includes a heating medium boiler B which has a combustion device capable of proportionally regulating a combustion amount and performs heating of heating medium according to combustion by means of a combustion device and a heat using part 2 which uses heat of the heating medium heated on the heating medium boiler B, and performs supply of heat by circulating the heating medium between the heating medium boiler and the heat using part. Therein, a "target temperature" of the heating medium to be supplied to the heat using part from the heating medium boiler and a "combustion amount necessary for elevating the temperature of the heating medium by 1°C" on the heating medium boiler are preset, at the same time, an inlet temperature measuring device 1 for measuring "an inlet temperature" of the heating medium which enters the heating medium boiler is provided on a heating medium return course for returning the heating medium from the heat using part to the heating medium boiler and the combustion amount on the heating medium boiler is determined according to "(target temperature-inlet temperature)×combustion amount necessary for elevating the temperature of the heating medium by 1°C".SELECTED DRAWING: Figure 1

Description

  In the present invention, the heat medium boiler and the heat use part are connected by a heat medium supply path and a heat medium return path, and heat is supplied by circulating the heat medium between the heat medium boiler and the heat use part. It is related to the heating medium boiler.

As described in Japanese Patent No. 2998573, the heat medium boiler and the heat use part are connected by a heat medium supply path and a heat medium return path, and the heat medium heated by the heat medium boiler is connected to the heat use part. There is known a heat medium boiler that supplies heat to a heat using part by circulating between them. The heat medium boiler has a combustion device that generates heat by combustion and a heat exchanger that absorbs the heat generated by the combustion device, and heats the heat medium by applying heat generated by the combustion to the heat medium. . The heat medium heated by the heat medium boiler is sent to the heat using part through the heat medium supply path. The heat using part uses the heat of the heat medium, and the heat medium whose temperature has decreased due to the use of heat returns to the heat medium boiler through the heat medium return path. By circulating the heat medium between the heat medium boiler and the heat use part and supplying heat with the heat medium boiler, the heat use part can continue to use heat.

In the case of a multi-can installation system in which a plurality of heat medium boilers are installed, a plurality of heat medium boilers are installed in parallel, and the heat medium taken out from each heat medium boiler is provided in the heat medium supply path. And collect it at the heat use section. In the installation of multiple cans of heat medium boilers, a number control device that controls the number of heat medium boilers that perform combustion according to the situation of the heat use part is provided, and based on the combustion command from the number control device, each boiler The amount of heat supplied is controlled by controlling the amount of combustion.

The amount of combustion in the heat medium boiler is detected by providing an inlet temperature detection device that detects the temperature of the heat medium entering the heat medium boiler or an outlet temperature detection device that detects the temperature of the heat medium coming out of the heat medium boiler. This is done by controlling the amount of combustion so that the heat medium temperature approaches the target temperature.

When the heat medium boiler controls the combustion amount proportionally, and the boiler combustion amount is controlled in accordance with the inlet temperature of the heat medium measured by the inlet temperature measuring device, the measured inlet temperature value becomes lower. Increase the amount of combustion in the heat medium boiler. When the inlet temperature becomes higher than the target temperature, the combustion amount in the heat medium boiler is set to the minimum combustion amount, and further, the heat supply amount in the heat medium boiler is reduced by stopping the combustion of the heat medium boiler, to the heat using part The combustion amount is controlled so that the temperature of the supplied heat medium becomes the target temperature. Also in the case of controlling at the outlet temperature, the combustion amount is controlled so that the temperature of the heat medium supplied to the heat using part becomes constant by increasing the combustion amount as the outlet temperature becomes lower.

However, the heating amount of the heat medium in the heat medium boiler is not determined only by the combustion amount of the boiler, but varies depending on the amount of soot attached, the flow rate of the heat medium, and the like. If soot adheres to the heat transfer tube of the heat medium boiler, the soot hinders the transfer of heat, so even if the combustion amount in the heat medium boiler is the same, the heat supply amount to the heat medium may be different . For this reason, there may be a difference between the required amount of combustion calculated from the heat medium temperature and the actually required amount of combustion, and if the amount of combustion is controlled with a difference in the control reference value, There was a possibility that the necessary amount of heat could not be supplied to the use section.

Japanese Patent No. 2998573

  The problem to be solved by the present invention is to accurately calculate the required amount of combustion when the amount of combustion in the heat medium boiler is controlled based on the temperature of the heat medium circulating with the heat using part. And it is providing the heat-medium boiler which can optimize the heat supply amount to a heat-use part.

The invention according to claim 1 includes a heat medium boiler having a combustion device capable of proportionally adjusting the amount of combustion, and heating the heat medium by combustion by the combustion device, and the heat medium boiler. A heat medium boiler having a heat using part that uses the heat of a heated heat medium and supplying heat by circulating the heat medium between the heat medium boiler and the heat using part. The “target temperature” of the heat medium supplied from the boiler to the heat use section and the “combustion amount necessary to raise the heat medium by 1 ° C.” are set in the heat medium boiler, and the heat medium boiler is set from the heat use section. An inlet temperature measuring device for measuring the “inlet temperature” of the heat medium entering the heat medium boiler is provided in the heat medium return path for returning the heat medium to “(target temperature−inlet temperature) × heat medium increased by 1 ° C. Combustion in a heating medium boiler by the amount of combustion required to Characterized in that so as to determine.

  The invention according to claim 2 is that, in the heat medium boiler, the “combustion amount necessary to raise the heat medium by 1 ° C.” is obtained from a predetermined value “temperature change = combustion amount of heat medium boiler (%)” Calculated as “Heat medium boiler combustion amount (%) ÷ Temperature change” using “Temperature change” obtained by “Amount of heat supplied by heat medium boiler ÷ (Specific heat of heat medium x Heat medium flow rate)” It is characterized by being.

  Invention of Claim 3 provides the header temperature measuring apparatus which measures the header temperature which is the temperature of the heat medium currently supplied to the heat-use part from the heat medium boiler in the said heat-medium boiler, and is entrance temperature. Is in a stable state, multiply the "combustion amount required to raise the heat medium by 1 ° C" by "(target temperature-inlet temperature) / (header temperature-inlet temperature)" A correction value of “amount of combustion necessary to raise the medium by 1 ° C.” is calculated.

By carrying out the present invention, the amount of combustion in the heat medium boiler can be controlled appropriately. Even if there is a deviation in the relationship between the amount of combustion in the heat medium boiler and the amount of heat supplied to the heat using part due to soot adhesion etc., the amount of heat supplied to the heat using part can be optimized and follow the load Can be improved.

Flow chart of heat medium boiler and heat using part in one embodiment of the present invention Explanatory drawing showing the setting of the number control in one embodiment of the present invention Flow diagram of heat medium boiler and heat using part in another embodiment of the present invention

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart of a heat medium boiler and a heat using part in one embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the setting of the number control in one embodiment of the present invention. Here, three heat medium boilers B are installed in parallel, and the heat medium is circulated between the three heat medium boilers (B1, B2, B3) and the heat using unit 2. The heat medium boiler B has a cylindrical combustion chamber whose side surface is formed by a coiled heat medium heating tube having a space in the center, and burns in the combustion chamber by a combustion device provided at the upper center. The heat medium in the heat medium heating tube is heated.

The heat generated in the heat medium boiler B is transferred through the heat medium. The heat medium boiler B and the heat use unit 2 are connected by the heat medium supply path 3 and the heat medium return path 5, and the heat medium can circulate between the heat medium boiler B and the heat use part 2. Keep it like that. The heat medium taken out from each heat medium boiler B is collected by the header and then sent to the heat using unit 2 through the heat medium supply path 3. The heat use unit 2 uses the heat of the heat medium supplied from the heat medium boiler, and the heat medium whose temperature has decreased by performing heat exchange in the heat use unit 2 passes through the heat medium return path 5. Returning to boiler B. The heat medium return path 5 is connected to each heat medium boiler B by branching in front of the heat medium boiler B, and the circulation pump 4 is provided in a portion after branching to each heat medium boiler B.

  The amount of combustion in the heat medium boiler B is controlled by the number controller 7 connected to the header temperature measuring device 6 provided in the heat medium supply path 3 and the inlet temperature measuring device 1 provided in the heat medium return path 5. To do. The inlet temperature measuring device 1 measures the temperature of the heat medium returning from the heat using part 2 to the heat medium boiler B through the heat medium return path 5, and the unit control device 7 measures the temperature with the inlet temperature measuring device 1. The combustion state of each heat medium boiler B is determined based on the inlet temperature of the heat medium that is being heated, and a combustion command is output to each heat medium boiler. The header temperature measuring device 6 measures the temperature of the heat medium supplied from the heat medium boiler B to the heat using unit 2 through the heat medium supply path 3. In the number control device 7, the header temperature measuring device 6 The combustion amount control is corrected based on the header temperature of the heat medium measured in step (b).

The number control device 7 reduces the combustion amount of the heat medium boiler B when the inlet temperature of the heat medium becomes high, and increases the combustion amount of the heat medium boiler B as the value of the inlet temperature decreases. The adjustment of the combustion amount is performed by combining proportional control that proportionally increases or decreases the combustion amount in each boiler and unit control that increases or decreases the number of combustion. As shown in FIG. 2, the combustion amount of the heat medium boiler B determines the combustion amount of the heat medium boiler B based on the value of the inlet temperature detected by the inlet temperature measuring device 1. In FIG. 2, the required combustion amount in the three heat medium boilers B is divided into the areas A and B according to the inlet temperature. In the heat medium boiler B in the embodiment, 25% combustion is set as the minimum combustion amount, and proportional control is performed between 25% combustion and 100% combustion.

Area A is when the inlet temperature becomes higher than the target temperature and the inlet temperature approaches the upper limit temperature. In this case, the number of combustion of the heat medium boiler is decreased as the inlet temperature approaches the upper limit temperature, and when the inlet temperature exceeds the upper limit temperature, the combustion of all the heat medium boilers B1, B2, and B3 is stopped. In the area A, the heat supply amount is adjusted according to the number of combustion. Here, even when combustion is performed, the combustion amount in the heat medium boiler is basically 25% combustion which is the minimum combustion amount. When the required combustion amount exceeds 12.5%, two heat medium boilers B1 and B2 perform 25% combustion. When the necessary combustion amount exceeds 25%, three heat medium boilers B1, B2, and B3 have 25% combustion. Burn.

When the heat medium boiler starts combustion in response to a command to start combustion, there is a time difference between the output of starting combustion and the actual supply of heat. For this reason, immediately after the start of combustion, a backup operation is performed to increase the amount of combustion in a boiler that has already performed combustion. For example, when 25% combustion is performed in the heat medium boiler B1 and combustion is stopped in the heat medium boiler B2, when a combustion command is output to the heat medium boiler B2, the number control device 7 uses the heat medium boiler. A command for changing the combustion amount from 25% combustion to 50% combustion is also output to B1. The transition from 25% combustion to 50% combustion in the burning boiler can be performed in a shorter time compared to the transition from combustion stop to 25% combustion in the combustion stop boiler, so that it is possible to prevent the amount of heat from becoming insufficient at startup. In this case, when combustion is started with a boiler that starts new combustion, the combustion amount is returned to 25% in the boiler that has increased the combustion amount from 25% to 50%.

In area B, all of the heat medium boilers B1, B2, and B3 are combusted. In this area, the heat medium boilers B1, B2, and B3 are between 25% combustion and 100% combustion based on the inlet temperature. Proportional combustion. In the number control device 7, the required combustion amount of the heat medium boiler is calculated from the value of the inlet temperature detected by the inlet temperature measuring device 8 at a constant cycle, and combustion is performed with the calculated combustion amount for each heat medium boiler. Output combustion instructions to do.

The combustion amount of the heat medium boiler is proportionally controlled by changing the combustion amount steplessly by the value of the inlet temperature. The calculation of the combustion amount is performed by the equation “(target temperature ° C.−inlet temperature ° C.) × combustion amount% required to raise the heating medium by 1 ° C. ÷ number of heating medium boilers”. For example, if the target temperature is 230 ° C, the inlet temperature is 215 ° C, the amount of combustion required to raise the heat medium by 1 ° C is 10%, and the number of heat medium boilers is 3, then each numerical value is applied to the above formula. (230−215) × 10 ÷ 3 = 50. In this case, the combustion amount of each boiler is set to 50%.

The inlet temperature varies depending on the amount of heat used in the heat using section 2. When the amount of heat used in the heat use unit 2 increases, the temperature of the heat medium that returns from the heat use unit 2 to the heat medium boiler B decreases. When the inlet temperature decreases to 200 ° C., it is necessary to increase the amount of combustion in the heat medium boiler B. If the required amount of combustion in this case is obtained from the above equation, (230−200) × 10 ÷ 3 = 100, so the amount of combustion in each boiler is 100%. When the calculated combustion amount exceeds 100%, the actual combustion amount becomes 100% because the heat medium boiler cannot perform combustion with an amount exceeding 100%.

Conversely, when the amount of heat used in the heat use unit 2 decreases, the temperature drop in the heat use unit 2 of the heat medium decreases, and thus the temperature of the heat medium returning from the heat use unit 2 to the heat medium boiler B increases. . When the inlet temperature rises to 220 ° C., the amount of combustion in the heat medium boiler B needs to be smaller than the above. If the inlet temperature = 220 ° C. is substituted into the above equation, (230−220) × 10 ÷ 3 = 33.3, so the combustion amount in each boiler is 33%. When the calculated combustion amount is less than 25%, the minimum combustion amount of the heat medium boiler in this embodiment is 25%, and combustion at less than 25% is not possible, so the actual combustion amount is 25 When the amount is fixed at% and the combustion amount is reduced from here, the number of boilers that perform combustion is adjusted.

In this way, by controlling the amount of combustion in the heat medium boiler B based on the inlet temperature, the temperature of the heat medium supplied from the heat medium boiler B to the heat using unit 2 can be adjusted to the target temperature. .

“The combustion amount% required to raise the heat medium by 1 ° C.” is a set value. The initial value of this value can be obtained by “temperature change = amount of heat supplied by the heating medium boiler / (specific heat of heating medium × flow rate of heating medium)” obtained from a predetermined value. For example, the amount of heat supplied by the heat medium boiler during 100% combustion of the heat medium boiler = 200,000 kcal / h (232.6 kW), the specific heat of the heat medium = 2.0 kcal / kg · ° C., and the flow rate of the heat medium = 10,000 kg / h. Then, temperature change (° C.) = Heat amount 200,000 (kcal / h) ÷ {specific heat 2.0 (kcal / kg · ° C.) × flow rate 10,000 (kg / h)} = 10 ° C. In other words, the heat medium rises by 10 ° C when the heat medium boiler is 100% combusted, so the “burning amount% required to raise the heat medium by 1 ° C” is 100 ÷ 10 = 10%, For every 10% change, the temperature of the heat medium changes by 1 ° C.

However, this “combustion amount% required to raise the heat medium by 1 ° C.” may be shifted when soot adheres to the heat transfer tube of the heat medium boiler B or when the diversion of the heat medium changes. become. Therefore, “the combustion amount% required to raise the heat medium by 1 ° C.” is corrected based on the actually measured value. The correction is performed when the inlet temperature is stable, and is multiplied by "(target temperature-inlet temperature) ÷ (header temperature-inlet temperature)". The correction value of “combustion amount% required to raise the heat medium by 1 ° C.” is calculated. When the inlet temperature is stable, the inlet temperature is maintained at ± T ° C. for t minutes.

For example, if the combustion amount required to raise the heat medium by 1 ° C. = 10%, target temperature = 230 ° C., inlet temperature = 200 ° C., header temperature = 225 ° C., combustion amount 10% × {(target temperature 230 ° C.−Inlet temperature 200 ° C.) ÷ (Header temperature 225 ° C.−Inlet temperature 200 ° C.)} = 10 × (30 ÷ 25) = 12. In other words, at the current “combustion amount% required to raise the heat medium by 1 ° C.” = 10%, the heat supply amount in the heat medium boiler is insufficient, so the combustion amount in the heat medium boiler increases. Thus, the combustion amount is controlled at “combustion amount% required to raise the heat medium by 1 ° C.” = 12%.

When the combustion amount is determined, the unit control device 7 outputs a combustion command to the heat medium boiler B. Each heat medium boiler B performs combustion based on a combustion amount command from the number control device 7. The boiler which has received the combustion command operates the circulation pump 4 and performs combustion by the combustion device, thereby heating the heat medium in the boiler. In the boiler that has received the combustion stop command, the circulation pump 4 and the combustion device are stopped.

The heating medium boiler adjusts the supply amount of combustion air with a blower that can increase or decrease the rotation speed by an inverter, and can adjust the fuel supply amount according to the required combustion amount. Combustion is performed with the combustion amount determined in 7. If the combustion amount of the boiler is controlled in stages, fires and abnormal combustion noises are generated when the combustion amount shifts, and hunting occurs depending on the load due to large changes in the temperature of the heat medium, stabilizing the temperature. Although it may be difficult, the occurrence of the above-described problems can be prevented by performing proportional control. In proportional control, not only the combustion amount control based on the inlet temperature of the heat medium, but also correction is made according to fluctuations in the heating capacity of the heat medium boiler. Can be kept in.

FIG. 3 relates to another embodiment of the present invention. In the above embodiment, a plurality of heat medium boilers are installed, and the combustion amount in each heat medium boiler is determined by the number control device 7, and each heat medium boiler is based on a command from the number control device. In the embodiment shown in FIG. 3, heat is supplied by a single heat medium boiler. In this case, the number control device 7 is not installed, and the combustion amount is determined by the operation control device 8 of the heat medium boiler. The basic control contents are the same as the above control, and the combustion amount of the boiler is determined by the equation of “(target temperature ° C.−inlet temperature ° C.) × combustion amount% required to raise the heating medium by 1 ° C.” To do. The only difference is that in the case of multiple cans, the amount of combustion in each boiler was calculated by dividing by the number of operating heat medium boilers, whereas in the case of single cans, there is no need to divide by the number of units in operation. So that part is different. Even in the case where a single can is installed, the “combustion amount% required to raise the heat medium by 1 ° C.” is corrected by the equation “(target temperature−inlet temperature) ÷ (header temperature−inlet temperature)”.

The present invention is not limited to the embodiments described above, and many modifications can be made by those having ordinary knowledge in the art within the technical idea of the present invention.

B Heat transfer boiler 1 Inlet temperature measuring device
2 Heat use part
3 Heat medium supply path
4 Circulation pump
5 Heat medium return path
6 Header temperature measuring device
7 Number control device 8 Operation control device

Claims (3)

  A heat medium boiler that has a combustion device capable of proportionally adjusting the amount of combustion, heats the heat medium by combustion with the combustion device, and uses the heat of the heat medium heated by the heat medium boiler A heat medium boiler that has a heat use part and supplies heat by circulating the heat medium between the heat medium boiler and the heat use part, the heat supplied from the heat medium boiler to the heat use part The “target temperature” of the medium and the “burning amount necessary to raise the heat medium by 1 ° C.” in the heat medium boiler are set, and the heat medium return path for returning the heat medium from the heat using part to the heat medium boiler In addition, an inlet temperature measuring device for measuring the “inlet temperature” of the heat medium entering the heat medium boiler is provided, and “(target temperature−inlet temperature) × combustion amount required to raise the heat medium by 1 ° C.” Determine the amount of combustion in the heat transfer boiler Heating medium boiler, characterized in that.   2. The heat medium boiler according to claim 1, wherein the “combustion amount necessary to raise the heat medium by 1 ° C.” is obtained from a predetermined value “temperature change = combustion amount of heat medium boiler (%)” Calculated as “heat medium boiler combustion amount (%) ÷ temperature change” using the “temperature change” obtained by “amount of heat supplied by ÷ (specific heat of heat medium × flow rate of heat medium)”. Heating medium boiler that is characteristic. The heating medium boiler according to claim 1 or 2, wherein a header temperature measuring device for measuring a header temperature that is a temperature of the heating medium supplied from the heating medium boiler to the heat using part is provided, and the inlet temperature is stabilized. In this state, “the amount of combustion necessary to raise the heating medium by 1 ° C.” is multiplied by “(target temperature−inlet temperature) ÷ (header temperature−inlet temperature)” to obtain “the heating medium as 1 A heating medium boiler characterized by calculating a correction value of "the amount of combustion necessary to raise the degree of C".

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