Combustion device

Abstract

The present invention provides a combustion device that can maintain an appropriate air-fuel ratio even when the amount of combustion is changed. [Solution] The system includes a first flow meter 200 for measuring the flow rate of combustion air flowing through a combustion air supply line, a first control valve 202 for changing the flow rate of combustion air, a second flow meter 300 for measuring the flow rate of gaseous fuel flowing through a gaseous fuel supply line, a pressure equalizing valve 301 for changing the flow rate of gaseous fuel according to the pressure of combustion air flowing through the combustion air supply line, a second control valve 302 for changing the flow rate of gaseous fuel, a first controller 101 for measuring the temperature of an unheated element and changing the amount of combustion, and a second controller 102 for calculating the required flow rate of combustion air according to the flow rate of gaseous fuel and controlling the first control valve 202 according to the calculated result.

Description

Technical Field

[0001] The present disclosure relates to a combustion device.

Background Art

[0002] Generally, a combustion device that mixes and burns gases flowing through a plurality of paths is used.

[0003] Patent Document 1 discloses a combustion device including a control device capable of controlling a first flow rate adjustment valve capable of adjusting the flow rate of hydrogen gas flowing through a hydrogen gas flow pipe and a second flow rate adjustment valve capable of adjusting the flow rate of hydrocarbon gas flowing through a hydrocarbon gas flow pipe.

[0004] Thereby, even when hydrogen gas is used as the fuel gas, safe operation is achieved while improving economy and work efficiency in operation.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the related combustion device disclosed in Patent Document 1, the flow meter used for individual flow rate control is not designed to be fail-safe, and the current value cannot always be guaranteed to be an accurate value. Therefore, there is a concern that the combustion air ratio cannot be properly maintained, resulting in excessive consumption of fuel due to an excessive amount of air or generation of unburned fuel due to an insufficient amount of air. In addition, it is not recognized as a protective system defined in JIS B 8415 or ISO, and it is difficult to be adopted overseas.

[0007] Here, the ISO standard includes requirements for individual flow control (electronic linkage control). Since Japan is exempt from this requirement, its adoption is possible domestically. However, this does not guarantee the accuracy of the flow meter readings and does not necessarily guarantee the maintenance of an appropriate air-fuel ratio in the combustion system.

[0008] Therefore, it was desirable to maintain an appropriate air-fuel ratio even when the combustion rate was changed by combining combustion rate adjustment through pressure equalization valve flow control, a protective system specified in JIS B 8415, with individual control of fuel and combustion air.

[0009] This disclosure provides a combustion device capable of maintaining an appropriate air-fuel ratio even when the combustion rate is changed. [Means for solving the problem]

[0010] The combustion apparatus according to this disclosure is a combustion apparatus that generates heat by burning a gaseous fuel, and comprises: a first flow meter for measuring the flow rate of combustion air flowing through a combustion air supply line; a first control valve for changing the flow rate of the combustion air; a second flow meter for measuring the flow rate of gaseous fuel flowing through a gaseous fuel supply line; a pressure equalizing valve for changing the flow rate of the gaseous fuel according to the pressure of the combustion air flowing through the combustion air supply line; a second control valve for changing the flow rate of the gaseous fuel; a first controller for measuring the temperature of an unheated element and changing the amount of combustion; and a second controller for calculating the required flow rate of the combustion air according to the flow rate of the gaseous fuel and controlling the first control valve according to the calculated result. This allows for safety to be ensured upstream through mechanical control, and enables the calculation and control of the required amount of air based on the fuel flow rate. [Effects of the Invention]

[0011] This disclosure provides a combustion device that can maintain an appropriate air-fuel ratio even when the amount of combustion is changed. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram showing an example of the configuration of a combustion device according to Embodiment 1. [Figure 2] This is a flowchart showing the operation of the combustion device according to Embodiment 1. [Modes for carrying out the invention]

[0013] Embodiment 1 The combustion apparatus according to this embodiment will be described below with reference to the drawings. Figure 1 is a diagram showing an example of the configuration of the combustion apparatus 1. The combustion apparatus 1 is a combustion apparatus that generates heat by burning a gaseous fuel. Here, the gaseous fuel will be described as hydrogen.

[0014] The combustion device 1 includes a first controller 101 and a second controller 102. The combustion device 1 also includes a combustion air supply line, a gaseous fuel supply line, and a nitrogen supply line. The combustion device utilizes the gases flowing through these lines to perform combustion in the combustion section 50.

[0015] The combustion device 1 includes a first flow meter 200 for measuring the flow rate of the combustion air supply line, a first control valve 202 for changing the flow rate of the combustion air, a second flow meter 300 for measuring the flow rate of the gaseous fuel flowing in the gaseous fuel supply line, a pressure equalizing valve 301 for changing the flow rate of the gaseous fuel according to the pressure of the combustion air supply line, a second control valve 302 for changing the flow rate of the gaseous fuel, a first controller 101 for changing the amount of combustion of the gaseous fuel by measuring the temperature of the unheated section, and a second controller 102 for calculating the required flow rate of combustion air according to the flow rate of the gaseous fuel and operating the first control valve.

[0016] The configuration will be explained in more detail below, with reference to Figure 1.

[0017] The first regulator 101 has a thermocouple. The first regulator 101 measures the temperature of the unheated body with the thermocouple and controls the hydrogen flow rate according to the measured temperature value and the target value. For example, the first regulator 101 outputs the measured temperature value and the target value to a second control valve 302 described later, and can change the combustion amount in the combustion device 1.

[0018] The second regulator 102 receives the input of the combustion air flow rate in the combustion air supply line from a first flow meter 200 described later and the input of the combustion gas flow rate in the gaseous fuel supply line from a second flow meter 300.

[0019] Specifically, in the second regulator 102, the necessary combustion air flow rate target is calculated from the gaseous combustion flow rate input from the second flow meter 300, and the operation of a first control valve 202 described later is controlled. Further, the combustion air flow rate in the combustion air supply line is input to the second regulator 102 from the first flow meter 200.

[0020] Next, the configurations of each of the combustion air supply line, the gaseous fuel supply line, and the nitrogen supply line will be described. First, an example of the configuration of the combustion air supply line will be described.

[0021] As shown in FIG. 1, the combustion air supply line has an inflow portion of combustion air, a filter 21, a blower 22, a pressure gauge 23, a pressure switch 24, a first flow meter 200, a first control valve 202, an orifice 25, a shut-off valve 26, and a check valve 27.

[0022] The filter 21 is a filtering device for preventing impurities mixed in the combustion air flowing in from the inflow portion from passing through.

[0023] The blower 22 applies energy to the air that has passed through the filter 21 to increase the pressure and the speed and send it out.

[0024] The pressure gauge 23 is an instrument for measuring the pressure applied to the combustion air increased by the blower 22.

[0025] The pressure switch SW24 is a switch that can be toggled according to the pressure measured by the pressure gauge 23. For example, if an abnormal value is measured in the pressure output of the pressure gauge 23, the pressure switch SW24 can be toggled to ensure safety in the combustion air supply line.

[0026] The first flow meter 200 is an instrument that measures the flow rate of combustion air flowing through the combustion air supply line. The flow rate of combustion air measured by the first flow meter 200 is output to the second controller 102.

[0027] The first control valve 202 controls the flow rate of combustion air in the combustion air supply line according to the target combustion air flow rate input from the second controller 102.

[0028] The orifice 25 is a restrictor for narrowing the flow of combustion air. For example, the orifice 25 is a conduit with reduced area that narrows the flow of combustion air that has passed through the first control valve 202.

[0029] The shut-off valve 26 is used to shut off the combustion air supply line. The shut-off valve 26 is located between the orifice 25 and the check valve 27.

[0030] The check valve 27 is a valve in the combustion air supply line that prevents backflow of gas from the combustion section 50 towards the shut-off valve 26.

[0031] In the combustion device 1, combustion air is supplied to the combustion section 50 via the combustion air supply line configured in this manner.

[0032] Next, we will describe an example of the configuration of a gaseous fuel supply line.

[0033] As shown in Figure 1, the gaseous fuel supply line includes a gaseous fuel inlet, a governor 31, a stop valve 32, a pressure gauge 33, a pressure switch (hereinafter referred to as pressure SW) 34, a second flow meter 300, a shut-off valve 35, a pressure equalizing valve 301, an orifice 36, a second control valve 302, a check valve 37, a thermocouple 38, and a flame arrestor 39.

[0034] Governor 31 is a fuel injection quantity control device. In other words, it can control the amount of fuel flowing in from the gaseous fuel inlet.

[0035] The stop valve 32 is a valve that can adjust the amount of gaseous fuel flowing through the gaseous fuel supply line. For example, the stop valve 32 can also stop the supply of gaseous fuel by completely closing the valve.

[0036] The pressure gauge 33 is an instrument for measuring the pressure applied to a gaseous fuel.

[0037] The pressure switch SW34 is a switch that can be toggled according to the pressure measured by the pressure gauge 33. For example, if an abnormal value is measured in the pressure output of the pressure gauge 33, the pressure switch SW34 can be toggled to ensure safety in the gaseous fuel supply line.

[0038] The second flow meter 300 is an instrument that measures the flow rate of combustion air flowing through the gaseous fuel supply line. The flow rate of the gaseous fuel measured by the second flow meter 300 is output to the second controller 102.

[0039] The shut-off valve 35 is a valve used to shut off the gaseous fuel supply line.

[0040] The pressure equalizing valve 301 is a valve that changes the flow rate of gaseous fuel according to the pressure in the combustion air supply line.

[0041] Orifice 36 is a restrictor used to narrow the flow of gaseous fuel. For example, orifice 36 is a conduit with reduced surface area.

[0042] The second control valve 302 changes its opening and closing based on the temperature value of the gaseous fuel input from the first controller 101 and the target value. In this way, the second control valve 302 controls the flow rate of the gaseous fuel in the gaseous fuel supply line.

[0043] The check valve 37 is a valve that prevents backflow of gas from the combustion section 50 towards the second control valve 302 in the gaseous fuel supply line.

[0044] A thermocouple 38 is typically a temperature sensor composed of two different metal conductors. A thermocouple 38 can measure the temperature of gaseous fuel in a gaseous fuel supply line.

[0045] The flame arrestor 39 is a safety device that allows gas to pass through under normal conditions, but extinguishes flames in the event of a fire to prevent a large-scale fire spread or explosion.

[0046] In the combustion device 1, gaseous fuel is supplied to the combustion section 50 via the gaseous fuel supply line configured in this manner.

[0047] The combustion section 50 includes a spark plug 51 and a flame detection unit 52.

[0048] The spark plug 51 is a plug that ignites a mixed gas, which is obtained by mixing the gases supplied to the combustion section 50 from the combustion air supply line, the gaseous fuel supply line, and the nitrogen supply line.

[0049] The flame detection unit 52 is a detection unit for confirming that combustion is occurring in the combustion unit 50.

[0050] Next, an example of the configuration of a nitrogen supply line will be described. The nitrogen supply line includes a shut-off valve 41 and a check valve 42.

[0051] The shut-off valve 41 is a valve used to shut off the nitrogen supply line.

[0052] The check valve 42 is a valve that prevents backflow of gas from the combustion section 50 towards the shut-off valve 26 in the nitrogen supply line.

[0053] The nitrogen supply line is connected between the check valve 37 of the gaseous fuel supply line and the flame arrester 39.

[0054] In the combustion device 1, nitrogen is supplied to the combustion section 50 via the nitrogen supply line configured in this way. More specifically, in the combustion device 1, the nitrogen supply line is connected to the gaseous fuel supply line, so that a gas mixture of gaseous fuel and nitrogen is supplied to the combustion section 50.

[0055] Next, an example of the operation of the combustion device 1 will be described with reference to Figure 2.

[0056] The first controller 101 measures the temperature of the non-heated element. The first controller 101 then controls the amount of gaseous fuel used for heating using the second control valve 302 (step S1).

[0057] The second flow meter 300 measures the flow rate of the gaseous fuel controlled by the second control valve 302 and outputs it to the second controller 102 (step S2).

[0058] The second controller 102 calculates the required combustion air flow rate, taking into account the air-fuel ratio, from the flow rate of the gaseous fuel. The second controller 102 also controls the first control valve 202 so that the combustion air flowing through the combustion air supply line matches the calculated combustion air flow rate (step S3).

[0059] The second controller 102 receives input of the combustion air flow rate measured by the first flow meter 200 (step S4).

[0060] The pressure equalizing valve 301 changes the pressure and flow rate of the gaseous fuel flowing through the gaseous fuel supply line based on the pressure of the combustion air controlled by the second controller 102 and the first control valve 202 (step S5).

[0061] The second controller 102 receives feedback of the gaseous fuel flow rate that has changed in accordance with the operation of the pressure equalizing valve 301 (step S6).

[0062] In the combustion device 1, the state of the first control valve 202 and the second control valve 302 is controlled as needed to maintain an appropriate air ratio between the gaseous fuel flowing in the gaseous fuel supply line and the combustion air flowing in the combustion air supply line (step S7).

[0063] For example, the first controller 101 controls the second control valve 302, and the second controller 102 controls the first control valve 202, and this is done as needed. In other words, the process returns to step S1 and is repeated.

[0064] This allows combustion device 1 to combine combustion rate adjustment using pressure equalization valve flow control, a protective system specified in JIS B 8415, with individual control of fuel and combustion air. Combustion device 1 can maintain an appropriate air-fuel ratio even when the combustion rate is changed, improving efficiency and thus reducing CO2 emissions.

[0065] In other words, the combustion device 1 can manage the relative ratio of gaseous fuel to combustion air through mechanical control by the pressure equalizing valve 301. Therefore, even if there are errors in the flow meter measurement or malfunction, or calculation errors or malfunctions in the controller, the combustion device 1 can operate safely as a whole.

[0066] In other words, in the combustion device 1, safety is ensured on the upstream side by mechanical control using the pressure equalizing valve 301, and the amount of combustion air required can be calculated and controlled by the second controller 102 according to the flow rate of the supplied gaseous fuel. As a result, the combustion device 1 can achieve both safety and the maintenance of an appropriate air-fuel ratio.

[0067] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. In other words, the above description has been omitted and simplified as appropriate for the sake of clarity, and those skilled in the art can easily change, add, and modify each element of the embodiments within the scope of the present invention.

[0068] For example, the nitrogen supply line shown in Figure 1 is installed to ensure safety when the gaseous fuel is highly flammable or combustible, that is, when a gas such as hydrogen is used as the gaseous fuel. Therefore, in combustion device 1, it is also possible to configure it without a nitrogen supply line, depending on the type of gas used as the gaseous fuel. [Explanation of symbols]

[0069] 1. Combustion device 21 filters 22 Blower 23 Pressure gauge 24 Pressure switches 25 Orifice 26 Shut-off valve 27 Check valve 31 Governor 32 Stop valve 33 Pressure gauge 34 Pressure switch 35 Shut-off valve 36 Orifice 37 Check valve 38 Thermocouples 39. Frame Arrester 41 Shut-off valve 42 Check valve 50 Combustion section 51 Spark plugs 52 Flame detection unit 101 First controller 102 Second controller 200 First flow meter 202 First control valve 300 Second flow meter 301 Pressure equalization valve 302 Second control valve

Claims

[Claim 1] A combustion device that generates heat by burning a gaseous fuel, A first flow meter for measuring the flow rate of combustion air flowing through the combustion air supply line, A first control valve that changes the flow rate of the combustion air, A second flow meter measures the flow rate of gaseous fuel flowing through the gaseous fuel supply line, A pressure equalizing valve that changes the flow rate of the gaseous fuel according to the pressure of the combustion air flowing through the combustion air supply line, A second control valve for changing the flow rate of the gaseous fuel, A first controller measures the temperature of the unheated element and changes the combustion rate, The system includes a second controller that calculates the required flow rate of combustion air according to the flow rate of the gaseous fuel and controls the first control valve according to the calculated result, Combustion device.

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