Warm water device

Abstract

Provided is a technique for determining whether or not a component corresponding to a gas is used in a warm water device that uses each of a plurality of gases. The process performed by the warm water device includes: a step (S710) in which a first ignition operation is performed in a first pilot mode; a step (S730) for determining that the combination of the gas and the adjustment component is abnormal when ignition is detected (YES in step (S720)); a step (S750) for executing a second ignition operation in a second pilot mode; a step (S780) for determining that the combination of the gas and the adjustment component is normal when ignition is detected (YES in step (S760)); and a step (S790) for determining that the combination of the gas and the adjustment component is abnormal when the ignition is not detected (NO in step (S760)).

Description

Technical Field

[0001] The present disclosure relates to a hot water device, and more particularly to a hot water device capable of using a plurality of gases as a heat source. Background Art

[0002] Conventionally, hot water devices corresponding to different types of gases used as heat sources have been known (for example, see Patent Documents 1 to 5).

[0003] [Prior Art Documents]

[0004] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent No. 3070720

[0006] [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-24354

[0007] [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-61026

[0008] [Patent Document 4] Japanese Patent No. 2567302

[0009] [Patent Document 5] Japanese Patent No. 3918550 Summary of the Invention

[0010] [Problems to be Solved by the Invention]

[0011] A hot water device sometimes uses parts corresponding to the gas depending on the gas used as the fuel for the heat source. Since the calorific values of the gases are different, in order for the hot water device to operate properly, parts corresponding to the gas are required. Therefore, a technique for accurately determining whether the combination of the gas and the parts is correct is needed.

[0012] In view of the above background, an object of the present disclosure is to provide a hot water device capable of determining whether the combination of a gas and parts to be used according to the gas is correct.

[0013] [Means for Solving the Problems]

[0014] According to an embodiment, a hot water device capable of using each of a plurality of gases as fuel is provided. The calorific value of the first gas among the plurality of gases is greater than that of the second gas. The hot water device includes: a Venturi tube having an air suction port and a gas suction port, and having a supply path for air and gas to a combustion chamber, and sucking the gas according to the negative pressure generated by the passing air; an adjustment part assembled into the gas supply path in a replaceable manner, and having a flow path for defining a supply amount corresponding to the type of gas; a fan for mixing air and gas and supplying the mixed air and gas to the combustion chamber; a burner for burning the gas; an ignition part for igniting the burner; a sensor for detecting that combustion is taking place in the combustion chamber; and a control device for operating the hot water device in a plurality of trial operation modes. In the first trial operation mode among the plurality of trial operation modes, the control device rotates the fan at a preset speed that is less than the speed at the time of normal ignition, causes the ignition part to ignite the burner, and if combustion is detected until a predetermined first time has elapsed since the ignition of the burner, it is regarded that the first gas is supplied to the combustion chamber, and the adjustment part for the second gas is assembled into the hot water device, thereby determining that the combination of the gas used as fuel and the adjustment part is incorrect.

[0015] In a certain situation, when the control device does not detect combustion in the first trial operation mode, it ends the first trial operation mode and transfers to a second trial operation mode different from the first trial operation mode, rotates the fan at a preset speed that is the speed at the time of normal ignition, causes the ignition part to ignite the burner, and if combustion is not detected until a predetermined second time has elapsed since the ignition of the burner, it is regarded that the second gas is supplied to the combustion chamber, and the adjustment part for the first gas is assembled into the hot water device, thereby determining that the combination of the gas used as fuel and the adjustment part is incorrect, and if combustion is detected until the second time has elapsed, it is determined that the assembly is correct.

[0016] The hot water device according to an embodiment can determine whether the combination of any one of a plurality of gases and the adjustment part is correct.

[0017] The above content and other objects, features, situations and advantages of the invention will become clear from the following detailed description of the invention understood in association with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram showing a part of the hardware structure of the hot water device 100 according to the present embodiment.

[0019] Figure 2 It is a diagram showing more specifically the structure of the Venturi tube 152 and the Venturi tube joint 160 in the gas supply part 140.

[0020] Figure 3 It is a graph showing the relationship between the volume percentage concentration (vol%) of CO2 at ignition and the time required for the mixture gas to ignite.

[0021] Figure 4 It is a graph showing the relationship between the rotational speed of the fan 154 at ignition and the time required for the mixture gas to ignite.

[0022] Figure 5 It is a graph showing the relationship between the rotational speed of the fan 154 for the same gas and the time required for the mixture gas to ignite.

[0023] Figure 6 It is a graph showing the outline of the process of determining whether the adjustment part 170 corresponding to the type of gas is installed in the venturi tube 152 in the hot water device 100.

[0024] Figure 7 It is a flowchart showing a part of the process executed by the control circuit 110 of the hot water device 100.

[0025] [Description of symbols]

[0026] 100: Hot water device

[0027] 110: Control circuit

[0028] 120: Spark plug

[0029] 122: Safety device

[0030] 124: Valve

[0031] 126: Flame column

[0032] 128: Thermistor

[0033] 129: Primary heat exchanger

[0034] 130: Secondary heat exchanger

[0035] 132: Exhaust duct

[0036] 134: Rectifying plate

[0037] 136: Tank

[0038] 137: Combustion chamber

[0039] 138: Burner

[0040] 140: Gas supply section

[0041] 150: Suction port

[0042] 152: Venturi tube

[0043] 153: Air hole

[0044] 154: Fan

[0045] 156: Elbow

[0046] 158: Mixing section

[0047] 160: Venturi joint

[0048] 162: Pressure equalizing air valve

[0049] 170: Adjusting part

[0050] 171, 202, 232: Flange

[0051] 210: Sealing ring Detailed implementation manners

[0052] Hereinafter, with reference to the accompanying drawings, the implementation manners of the present invention will be described. In the following description, the same reference numerals are assigned to the same parts. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0053] Among the combustion manners used in the hot water device, there is a full primary air combustion manner. In the full primary air combustion manner, the hot water device sucks all the air required for combustion as primary air, mixes the primary air with the gas used as fuel, and sends the mixed air and gas into the combustion chamber. The gas is, for example, liquefied petroleum (LP) gas, natural gas, etc.

[0054] The hot water device 100 according to the present implementation manner adopts a full primary air combustion manner in which the gas and air are pre - completely mixed and then burned. In this manner, compared with other manners (such as the rich - lean combustion manner), the residual air is less, so an improvement in thermal efficiency can be expected. In addition, for the NOx (nitrogen oxides) discharged, a reduction thereof can also be expected.

[0055] Refer to Figure 1 , the structure of the hot water device 100 will be described. Figure 1 is a diagram showing a part of the hardware structure of the hot water device 100 according to the present implementation manner. The hot water device 100 includes a control circuit 110, a tank body 136, an exhaust duct 132, a gas supply part 140, a fan 154, and an elbow 156.

[0056] The tank body 136 includes a spark plug 120, a safety device 122, a valve 124, a flame rod 126, a thermistor 128, a primary heat exchanger 129, a secondary heat exchanger 130, a rectifying plate 134, and a burner 138.

[0057] The air supply unit 140 includes a Venturi tube 152, a Venturi tube joint 160, a pressure equalizing air valve 162, and an adjustment part 170. The Venturi tube 152 includes an air inlet 150 and an air hole 153. The air inlet 150 takes in air. The pressure equalizing air valve 162 is connected to the gas supply pipe and maintains the pressure of the gas sent to the Venturi tube joint 160 at a constant value. When the fan 154 rotates, air flows in from the air inlet 150, and the gas used as fuel flows in from the air hole 153 according to the negative pressure generated by the passing air. The air and gas flowing into the Venturi tube 152 are sent to the mixing part 158 through the elbow 156. In the mixing part 158, the fan 154 mixes the air and gas. The mixed air and gas are sent to the combustion chamber 137 as the mixed gas for combustion.

[0058] The control circuit 110 controls the operation of the hot water device 100. The spark plug 120 receives a high voltage from an igniter (not shown) and performs a spark discharge. After the burner 138 is ignited by the spark, the mixed gas supplied to the combustion chamber 137 burns. After the combustion starts, the temperature of the water flowing into the primary heat exchanger 129 from the outside of the hot water device 100 rises.

[0059] The safety device 122 detects that the combustion of the burner 138 spreads in a direction different from the direction where the primary heat exchanger 129 is provided, and sends a signal indicating the detection to the control circuit 110. After receiving the signal, the control circuit 110 closes the valve 124, thereby stopping the supply of the mixed gas.

[0060] The flame column 126 monitors the ignition and combustion in the tank body 136. The monitoring result is sent to the control circuit 110. The control circuit 110 can inform the results such as poor combustion and normal operation according to the monitoring result.

[0061] The thermistor 128 detects the temperature of the water (hot water) supplied to the primary heat exchanger 129. The secondary heat exchanger 130 recovers the latent heat from the exhaust gas after the primary heat exchange and heats the water supplied to the secondary heat exchanger 130.

[0062] The exhaust duct 132 is connected to the outside of the hot water device 100 and sends out the exhaust gas after the heat exchange. The rectifying plate 134 arranges the flow of the exhaust gas, thereby efficiently sending out the exhaust gas.

[0063] The adjustment part 170 is provided between the Venturi tube 152 and the Venturi tube joint 160. The Venturi tube joint 160 is connected to the pipe provided with the pressure equalizing air valve 162 for controlling the amount of the supplied gas.

[0064] The adjustment part 170 is a part for adjusting the supply amount of the gas supplied to the hot water device 100 according to the characteristics of the gas. In order to change the size of the air hole 153 formed in the venturi tube 152, it is necessary to remanufacture the venturi tube 152 itself. On the other hand, by assembling the adjustment part 170 into the venturi tube joint 160, without modifying the venturi tube 152, in fact, the same amount of flow corresponding to the gas is supplied as in the case where the size of the air hole 153 is set to a size corresponding to the characteristics of the gas used.

[0065] More specifically, the adjustment part 170 includes a hollow part through which the gas passes. The hollow part includes a throttling part. The inner diameter (orifice diameter) of the throttling part is determined according to the calorific value of the gas so as to limit the supply amount in the same way as the air hole 153. Therefore, the constructor of the hot water device 100 selects an appropriate adjustment part 170 according to the type of gas used as the fuel of the hot water device 100 and assembles it between the venturi tube 152 and the venturi tube joint 160, whereby an air hole 153 with an appropriate throttling aperture diameter can be adopted without machining the venturi tube 152.

[0066] Here, the relationship between the characteristics of the gas used in the hot water device 100 and the adjustment part 170 will be described. The hot water device 100 can use natural gas and LP gas as fuel. The calorific value of natural gas (about 54 MJ / Nm 3 ) is smaller than the calorific value of LP gas (about 81 MJ / Nm 3 ).

[0067] Refer to Figure 2 for a further description of the structure of the gas supply part 140. Figure 2 is a diagram showing more specifically the structures of the venturi tube 152 and the venturi tube joint 160 in the gas supply part 140.

[0068] The venturi tube 152 includes a flange 202. The venturi tube joint 160 includes a flange 232. The adjustment part 170 includes a flange 171. The flange 232 of the venturi tube joint 160 is joined to the flange 202 of the venturi tube 152 via a sealing ring 210. If the flange 232 of the venturi tube joint 160 and the flange 202 of the venturi tube 152 are joined by bolts (not shown), the adjustment part 170 functions as an air hole 153 corresponding to the gas used as fuel.

[0069] As an example, the dimensions (such as the throttling aperture diameter) that define the flow rate of the adjustment part 170 used when supplying either natural gas or LP gas as fuel are in the following relationship.

[0070] · Throttle aperture of the adjustment part 170 for natural gas (about 7.9φ) > Throttle aperture of the adjustment part 170 for LP gas (about 7.7φ)

[0071] Therefore, for example, when LP gas is used as fuel, if the adjustment part 170 with a large throttle aperture for natural gas is used, a gas with a calorific value higher than required is supplied to the combustion chamber 137. As a result, incomplete combustion caused by so-called gas rich occurs in the combustion chamber 137, and carbon monoxide is abnormally generated. Therefore, the hot water device 100 according to the present embodiment has a two-stage commissioning mode. In the first commissioning mode, the fan 154 operates at a speed lower than the speed at normal ignition to perform determination related to LP gas. Then, the hot water device 100 switches to the second commissioning mode. The fan 154 operates at the speed at normal ignition to perform determination related to natural gas.

[0072] Refer to Figure 3 to explain the relationship between the volume percentage concentration of CO2 and the ignition time. Figure 3 It is a graph showing the relationship between the volume percentage concentration (vol%) of CO2 at ignition and the time required for ignition of the air-fuel mixture. Region 300 represents the ignitable range. It is clear from Figure 3 that the lower the volume percentage concentration of CO2 at ignition, the longer the ignition time.

[0073] Refer to Figure 4 to explain the relationship between the speed of the fan 154 and the ignition time. Figure 4 It is a graph showing the relationship between the speed of the fan 154 at ignition and the time required for ignition of the air-fuel mixture. Region 400 represents the ignitable range. It is clear from Figure 4 that the lower the speed of the fan 154 at ignition, the longer the ignition time. For example, when the speed is r (rpm), the ignition time is t(1) seconds. Since the fuel is gas, t(1) seconds is several seconds.

[0074] In the case of using gas as fuel, if the types of gas are the same, the larger the throttle aperture of the gas supply passage, the more gas is supplied, so the gas concentration of the air-fuel mixture becomes higher. The hot water device 100 according to the present embodiment adopts a full primary air combustion method of igniting by discharging a spark to the air-fuel mixture. In this method, if the gas concentration becomes higher, more gas molecules undergo an oxidation reaction per unit time, so the ignition timing becomes earlier (that is, the time required for ignition becomes shorter). Also, the same applies to the rotational speed of the fan 154. That is, if the fan 154 operates at a low rotational speed, less air-fuel mixture is sent into the combustion chamber 137, and fewer gas molecules react per unit time. As a result, the ignition timing is delayed (that is, the time required for ignition becomes longer). The hot water device 100 according to the present embodiment uses this relationship to determine whether the combination of the gas used as fuel and the adjustment part 170 is correct or incorrect.

[0075] Therefore, with reference to Figure 5 , the difference in the ignitable range caused by the adjustment part will be described. Figure 5 is a graph showing the relationship between the rotational speed of the fan 154 and the time required for ignition of the air-fuel mixture for the same gas. The region 500 represents the difference in the ignitable range. The line 510 defines the ignitable range when the adjustment part is for LP gas. The line 520 defines the ignitable range when the adjustment part is for natural gas. Therefore, the region 500 represents the difference between these ignitable ranges.

[0076] That is, in the case of the same gas, the throttle aperture of the adjustment part 170 for LP gas is different from that of the adjustment part 170 for natural gas, so the rotational speed at which ignition starts (ignitable rotational speed) is also different. More specifically, considering the difference in the calorific value of each gas, the throttle aperture of the adjustment part 170 for LP gas is smaller than that of the adjustment part 170 for natural gas. Therefore, within the range of the ignitable rotational speed, the hot water device 100 can use the trial operation mode for ignition to determine whether the combination of the gas type and the adjustment part 170 is correct or incorrect.

[0077] In another aspect, the hot water device 100 can change the time for determining whether ignition occurs according to the trial operation mode. The shorter this time is, the greater the difference in the ignitable rotational speed based on the adjustment part 170, so the hot water device 100 can accurately determine whether the combination is correct.

[0078] When using natural gas as fuel, a user (e.g., a person setting up the hot water device 100) rotates the fan 154 at the rotation speed during normal ignition to perform the ignition operation of the hot water device 100, thereby identifying whether the adjustment part 170 corresponding to the type of gas is used. That is, considering that the calorific value of natural gas is less than that of LP gas, the throttle aperture of the adjustment part 170 for natural gas is larger than that of the adjustment part 170 for LP gas. Therefore, when using natural gas as fuel, if ignition is performed while the fan 154 is operating at the rotation speed during normal ignition, the adjustment part 170 with a larger throttle aperture, that is, the adjustment part 170 for natural gas, is used, so the combination of the gas and the adjustment part 170 is correct. On the other hand, when using natural gas as fuel, if ignition does not occur while the fan 154 is operating at the rotation speed during normal ignition, the required amount of gas is not supplied, and the adjustment part 170 with a smaller throttle aperture, that is, the adjustment part 170 for LP gas, is wrongly used. When using natural gas as fuel, it is thus possible to identify whether the established adjustment part 170 is correctly used.

[0079] [Determination process]

[0080] Refer to Figure 6 , and the determination process performed on the hot water device 100 will be described. Figure 6 It is a diagram showing an outline of the process of determining whether the adjustment part 170 corresponding to the type of gas is installed in the venturi tube 152 in the hot water device 100. Figure 6 The process shown is executed when the operation mode of the hot water device 100 is the trial operation mode. In the present embodiment, the trial operation mode may include multiple modes. Regarding the multiple modes, hereinafter, they will be described in the form of the first trial operation mode and the second trial operation mode.

[0081] In step S610, after the control circuit 110 detects an instruction to start the trial operation, the first trial operation mode is started. The instruction to start the trial operation is detected by pressing a physical switch (not shown) provided in the hot water device 100 or by inputting a control code indicating an instruction for the trial operation. The control circuit 110 rotates the fan 154 at a low rotation speed (e.g., Figure 5 r(1) rpm) preset as a rotation speed lower than the normal rotation speed, and supplies the air-fuel mixture to the combustion chamber 137 to start the ignition operation.

[0082] After the ignition operation starts, there may be a situation where the gas ignites within a predetermined time and a situation where it does not ignite. For example, in a certain situation, when the combination of the type of gas used as fuel and the adjustment part 170 is normal, the fan 154 rotates at a speed below the speed required for gas ignition, so the gas does not ignite (process S620). In another situation, when natural gas is used as fuel and the LP gas adjustment part 170 is used for the venturi tube 152, since the throttle aperture of the LP gas adjustment part 170 is smaller than that of the natural gas adjustment part 170, the fuel required for combustion is not supplied either, and the gas does not ignite (process S630).

[0083] On the other hand, when LP gas is used as fuel and the natural gas adjustment part 170 is assembled into the hot water device 100, the fuel required for ignition is supplied because the throttle aperture of the natural gas adjustment part 170 is larger than that of the LP gas adjustment part 170, so the gas ignites (process S670). In this case, since the wrong adjustment part 170 (i.e., the natural gas adjustment part 170) that is not required for the gas (LP gas) used is assembled into the venturi tube 152, the control circuit 110 determines that the combination of the gas and the adjustment part 170 is abnormal (process S680).

[0084] In the case where the gas does not ignite (process S620 or process S630), the control circuit 110 switches the operation mode of the hot water device 100 to the second trial operation mode (process S640). In the second trial operation mode, the control circuit 110 rotates the fan 154 at a speed (r(2) rpm) preset as the speed that should be in the normal operation of the hot water device 100 and supplies the mixed gas to the combustion chamber 137. In this case, r(1) < r(2).

[0085] When the combination of the type of gas used and the gas adjustment part 170 is correct, the gas ignites (process S650). Therefore, the control circuit 110 determines that the combination of the gas and the adjustment part 170 is correct (determined to be normal, process S670).

[0086] On the other hand, in the case where the gas does not ignite (process S660), since the wrong adjustment part 170 (i.e., the LP gas adjustment part 170) that is not required for the natural gas used is assembled into the venturi tube 152, the control circuit 110 determines that the combination of the gas and the adjustment part 170 is incorrect (determined to be abnormal, process S680).

[0087] [Control Structure]

[0088] Refer to Figure 7, the control structure of the warm water device 100 will be described. Figure 7 It is a flowchart showing a part of the processing executed by the control circuit 110 of the warm water device 100.

[0089] In step S710, the control circuit 110 switches the operation mode of the warm water device 100 to the first trial operation mode and performs the first ignition operation under the predetermined first operating conditions. More specifically, the control circuit 110 turns on the igniter (not shown) so that the spark plug 120 can ignite, opens the gas valve, and starts the supply of gas. At this time, the control circuit 110 sets the rotational speed of the fan 154 to r(1) (rpm) and determines whether there is ignition based on the threshold time (t(1) (seconds)) predetermined as the ignition determination time.

[0090] In step S720, the control circuit 110 determines whether combustion is in progress. More specifically, the control circuit 110 determines whether the flame column 126 is on. When it is determined that the flame column 126 is on (in step S720, it is "YES"), the control circuit 110 switches the control to step S730. In the case where this is not the case (in step S720, it is "NO"), the control circuit 110 switches the control to step S740.

[0091] In step S730, the control circuit 110 determines that the combination of the gas used as fuel and the adjustment part 170 is abnormal (error) ( Figure 6 step S670), and ends the first trial operation mode. Furthermore, the control circuit 110 executes an error notification ( Figure 6 step S680) notifying the combination abnormality. After that, the control circuit 110 ends the operation of the warm water device 100.

[0092] In step S740, the control circuit 110 purges the combustion chamber 137 to discharge air from the combustion chamber 137.

[0093] In step S750, the control circuit 110 switches the operation mode of the warm water device 100 to the second trial operation mode and performs the second ignition operation under the predetermined second operating conditions. More specifically, the control circuit 110 turns on the igniter so that the spark plug 120 can ignite and opens the gas valve. At this time, the control circuit 110 sets the rotational speed of the fan 154 to r(2) (rpm) and determines whether there is ignition based on the threshold time (t(2) (seconds)) predetermined as the ignition determination time. Here, r(1) < r(2), and t(1) ≥ t(2).

[0094] In process S760, the control circuit 110 determines whether combustion is in progress. More specifically, the control circuit 110 determines whether the flame column 126 is on. When it is determined that the flame column 126 is on (YES in process S760), the control circuit 110 switches the control to process S770. In the case where this is not so (NO in process S760), the control circuit 110 switches the control to process S790.

[0095] In process S770, the control circuit 110 scavenges the combustion chamber 137 to discharge air from the combustion chamber 137.

[0096] In process S780, the control circuit 110 determines that the combination of the gas used and the adjustment part 170 is normal, outputs a determination result indicating that the combination is correct, and ends the second trial operation mode.

[0097] In process S790, the control circuit 110 determines that the combination of the gas used and the adjustment part 170 is abnormal ( Figure 6 in process S660), outputs a determination result indicating that the combination is incorrect, and ends the second trial operation mode. Further, the control circuit 110 executes an error notification ( Figure 6 in process S680) notifying the combination error. After that, the control circuit 110 ends the operation of the hot water device 100.

[0098] That is, in the first trial operation mode, the control circuit 110 performs an ignition operation while rotating the fan 154 at a speed (r(1)) less than the predetermined speed. In the case where the air-fuel mixture is ignited, a combination error of the gas and the adjustment part 170 (using the adjustment part 170 for natural gas for LP gas) is detected, and a determination result indicating the situation is output. On the other hand, in the case where the air-fuel mixture is not ignited by the ignition operation, the control circuit 110 transfers to the second trial operation mode.

[0099] In the second trial operation mode, the control circuit 110 performs an ignition operation while rotating the fan 154 at the normal speed. In the case where ignition does not occur, the control circuit 110 detects a combination error of the gas and the adjustment part 170 (using the adjustment part 170 for LP gas for natural gas), determines that the combination is abnormal, and outputs a determination result. On the other hand, in the case where the air-fuel mixture is ignited by the ignition operation, the control circuit 110 determines that the combination of the gas and the adjustment part 170 is correct, outputs a determination result indicating the situation, and ends the second trial operation mode.

[0100] When the control circuit 110 determines that the combination is incorrect, it issues an error notification, and performs message display, sound output, indicator lighting, etc. to prompt the confirmation of the adjustment part 170. In this case, the operation mode of the hot water device 100 remains the trial operation mode. On the other hand, if it is determined that the combination is correct, the control circuit 110 notifies of the situation and ends the trial operation mode of the hot water device 100.

[0101] As described above, the hot water device 100 according to the present embodiment determines whether the combination of the gas and the adjustment part 170 is correct only based on the rotation speed at the time of ignition. Therefore, the determination can be achieved without complicating the structure of the hot water device 100. The hot water device 100 determines whether the combination of the gas type and the adjustment part 170 is correct within several seconds of determining the presence or absence of ignition. Therefore, the determination can be made in a short time. In addition, the fan 154 operates at a low rotation speed, so it is not easily affected by so-called explosion caused by ignition delay and ignition in a state where gas is accumulated. Therefore, the determination can be achieved without causing uneasiness to the installer or the end user of the hot water device 100.

[0102] It should be considered that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is represented by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A water heater capable of using a plurality of gases as fuel, wherein a first gas among the plurality of gases has a greater calorific value than a second gas, the water heater comprising: The venturi tube has an air intake port and a gas intake port, and has a supply path for air and gas to the combustion chamber, and sucks gas according to the negative pressure generated by the passing air; The adjustment part is replaceably incorporated into the gas supply path and has an inner diameter corresponding to the type of gas; a fan, mixing air and gas, and supplying the mixed air and gas to the combustion chamber; a burner for burning the gas; An ignition unit, igniting the burner; a sensor for detecting that combustion is occurring in the combustion chamber; as well as A control device is provided to operate the warm water device in a plurality of trial operation modes, In the control device, In a first test operation mode among the plurality of test operation modes, the fan is rotated at a speed that is preset as a speed lower than the speed during normal ignition. causing the ignition unit to ignite the burner, When combustion is detected after a predetermined first time has passed since the ignition of the burner, it is deemed that the first gas is supplied to the combustion chamber, and the adjustment parts for the second gas are incorporated into the hot water device, thereby determining that the combination of the gas used as fuel and the adjustment parts is incorrect.

2. The warm water device according to claim 1, wherein: In the control device, If combustion is not detected in the first test operation mode, the first test operation mode is terminated and the mode is shifted to a second test operation mode different from the first test operation mode. The fan is rotated at a predetermined rotation speed as a rotation speed during normal ignition. causing the ignition unit to ignite the burner, If combustion is not detected within a predetermined second time from the ignition of the burner, it is considered that the second gas is supplied to the combustion chamber, and an adjustment part for the first gas is incorporated into the hot water device, thereby determining that the combination of the gas used as fuel and the adjustment part is incorrect. If combustion is detected before the second time has elapsed, it is determined that the incorporation is correct.

3. The warm water device according to claim 1 or 2, wherein: The first gas is liquefied petroleum gas, The second gas is natural gas. 4 . The warm water device according to claim 1 , further comprising a notification unit for notifying a result of any of the determinations.

5. The warm water device according to claim 4, wherein: The notification unit comprises: A display device or a speaker provided in the water heater, or A remote controller capable of wirelessly communicating with the water heater or a transmitter capable of wirelessly communicating with the water heater transmits a signal indicating the result of the notification to an information communication terminal capable of wirelessly communicating with the water heater.

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