Combustion device

Abstract

To carry out an ignition control suitably corresponding to the velocity of wind blowing through an exhaust port in a combustion device comprising a burner burning gas.SOLUTION: A control device 70, i.e., an example of a controller, carries out a first preliminary operation to rotate a fan 20 at a first rotation speed prior to igniting gas by an ignition plug 85, and carries out a second preliminary operation to rotate the fan 20 at a second rotation speed higher than the first rotation speed when the velocity of the wind blowing through an exhaust port 90 is equal to or higher than a reference velocity YB during the first preliminary operation. When the wind velocity of the wind blowing through the exhaust port 90 during the first preliminary operation is lower than a first wind velocity Y1, or when the wind velocity of the wind blowing through the exhaust port 90 during the second preliminary operation is equal to or lower than a second wind velocity Y2 which is higher than the reference wind velocity YB, the control device 70 causes the ignition plug 85 to carry out the ignition operation to allow the burner to carry out combustion.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a heat source machine. This heat source machine includes a burner that burns fuel gas and a combustion fan that supplies combustion air toward the burner. Until a flame due to ignition of the fuel gas by an ignition plug is detected, the combustion fan is rotated at a rotation speed for blockage detection. The drive current value at this time is detected, and the degree of the wind pressure at the outdoor exhaust port is detected based on the detected drive current value. When the degree of the wind pressure exceeds an allowable degree, ignition of the fuel gas is aborted to avoid the occurrence of explosive ignition. On the other hand, when the degree of blockage is within an allowable range, the fuel gas is ignited using the ignition plug while rotating the combustion fan at an ignition rotation speed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The configuration of Patent Document 1 described above detects whether the wind pressure at the outdoor exhaust port exceeds an allowable level based on the drive current value of the fan when the fan is rotated at a predetermined rotation speed for blockage detection, and aborts ignition when the allowable level is exceeded. However, with such a method alone, there is a concern that if the wind speed of the wind blowing out of the exhaust port suddenly increases or an unexpected false determination occurs, ignition will be immediately aborted, reducing the convenience for the user.

[0005] One object of the present disclosure is to perform ignition control that appropriately responds to the wind speed of the wind blowing out of the exhaust port in a combustion device including a burner that burns gas.

Means for Solving the Problems

[0006] A combustion device which is one of the present disclosures includes a burner for burning gas, a container for housing the burner, a fan for supplying air into the container, ignition means for igniting the gas supplied to the burner, and is a combustion device comprising: a control unit for controlling the ignition operation of the ignition means and the rotation of the fan; an exhaust port which is a path for discharging combustion exhaust gas generated by the combustion of the gas from the container to the outside of the combustion device; the control unit performs a first preliminary operation to rotate the fan at a first rotational speed before igniting the gas by the ignition means; performs a second preliminary operation to rotate the fan at a second rotational speed greater than the first rotational speed on the condition that the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than a predetermined reference wind speed; when the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is less than a first wind speed which is less than the reference wind speed, the burner is burned by causing the ignition means to perform an ignition operation with the fan rotating at a predetermined ignition rotational speed; when the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than the first wind speed and less than the reference wind speed, or when the wind speed of the wind blowing out of the exhaust port during the second preliminary operation is equal to or lower than a second wind speed which is greater than the reference wind speed, the burner is burned by causing the ignition means to perform an ignition operation with the fan rotating at an ignition rotational speed higher than the predetermined ignition rotational speed Combustion device.

Advantages of the Invention

[0007] The technology according to the present disclosure can easily perform ignition control corresponding appropriately to the wind speed of the wind blowing out of the exhaust port in a combustion device including a burner for burning gas.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0009] Each of the following [1] to [4] is an example of a combustion device included in the present disclosure. [1] A burner for burning gas, A container for housing the burner, A fan for supplying air into the container, Ignition means for igniting the gas supplied to the burner, A combustion device comprising: A control unit for controlling the ignition operation of the ignition means and the rotation of the fan, An exhaust port which is a path for discharging the combustion exhaust gas generated by the combustion of the gas from the container to the outside of the combustion device, The control unit: Before igniting the gas by the ignition means, a first preliminary operation is performed to rotate the fan at a first rotational speed, On the condition that the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than a predetermined reference wind speed, a second preliminary operation is performed to rotate the fan at a second rotational speed greater than the first rotational speed, When the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is less than a first wind speed lower than the reference wind speed, with the fan rotating at a predetermined ignition rotational speed, the ignition means is made to perform an ignition operation to burn the burner, When the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than the first wind speed and lower than the reference wind speed, or when the wind speed of the wind blowing out of the exhaust port during the second preliminary operation is equal to or lower than the second wind speed which is higher than the reference wind speed, the burner is burned by causing the ignition means to perform an ignition operation while the fan is rotating at an ignition rotation speed higher than the predetermined ignition rotation speed. Combustion device.

[0010] In the combustion device of the above [1], when the wind speed of the wind blowing out of the exhaust port when the fan is rotated at a relatively low first rotation speed (during the first preliminary operation) is lower than the first wind speed, it is highly likely that the blockage near the exhaust port is low. In this case, ignition can be performed earlier. When the wind speed of the wind blowing out of the exhaust port during the second preliminary operation is equal to or higher than the reference wind speed, it is possible that the blockage near the exhaust port is high. In this case, the wind speed can be accurately measured by rotating the fan at a relatively high second rotation speed. Further, even when the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than the first wind speed but lower than the reference wind speed, or when the wind speed of the wind blowing out of the exhaust port during the second preliminary operation is equal to or lower than the second wind speed which is higher than the reference wind speed, the burner can be burned by performing an ignition operation while the fan is rotated at an ignition rotation speed higher than the predetermined ignition rotation speed. That is, even if the ignition conditions cannot be cleared immediately in the first preliminary operation, the combustion device can carefully re-determine the blockage based on the second preliminary operation, and burn the burner when the conditions are cleared. Therefore, the combustion device can easily perform ignition control appropriately corresponding to the wind speed of the wind blowing out of the exhaust port.

[0011] 〔2〕When the variation range of the wind speed within the first specified period in which the fan is rotated at the second rotation speed during the second preliminary operation is within a predetermined value, and when the wind speed of the wind blowing out of the exhaust port is equal to or lower than the second wind speed, the burner is burned by causing the ignition means to perform an ignition operation while the fan is rotated at an ignition rotation speed higher than the predetermined ignition rotation speed. The combustion device according to [1].

[0012] In the combustion device of [2] above, when the fluctuation range of the wind speed during the period when the fan is rotated at the second rotational speed during the second preliminary operation is within a predetermined value, that is, when there is a high possibility that the rotational speed of the fan is stable, and the wind speed at the exhaust port is equal to or lower than the second wind speed, the ignition operation can be performed, so that ignition can be achieved more reliably.

[0013] 〔3〕When the wind speed of the wind blowing out of the exhaust port is greater than the second wind speed during the second specified period when the fan is rotated at the second rotational speed during the second preliminary operation, the control unit waits without performing the ignition operation of the ignition means while maintaining the fan at the second rotational speed until the wind speed becomes equal to or lower than the second wind speed. When the wind speed of the wind blowing out of the exhaust port becomes equal to or lower than the second wind speed during the waiting period, the control unit causes the ignition means to perform the ignition operation to burn the burner while rotating the fan at an ignition rotational speed higher than the predetermined ignition rotational speed. The combustion device according to [1] or [2].

[0014] In the combustion device of [3] above, when strong wind blows at the exhaust port during the second preliminary operation, the ignition operation is not performed and the device waits, thereby preventing poor ignition and explosive ignition. Since the second preliminary operation can be continued without interruption during the waiting period, the ignition operation can be performed more quickly when the wind speed becomes equal to or lower than the second wind speed.

[0015] 〔4〕The first specified period is shorter than the second specified period. The combustion device according to [3].

[0016] In the combustion device of [4] above, by shortening the first specified period, the subsequent operation can be accelerated, so that ignition can be performed relatively early. Also, by lengthening the second specified period, the possibility of finally performing the ignition operation is increased, so that situations such as cancellation of ignition contrary to the user's intention can be suppressed.

[0017] 〔5〕An electric current detection unit that detects the drive current supplied to the fan, A rotational speed sensor that detects the rotational speed of the fan, are provided. The control unit determines the wind speed of the wind blowing out of the exhaust port based on the current detected by the current detection unit and the rotational speed detected by the rotational speed sensor. The combustion device according to any one of [1] to [4].

[0018] The hot water heater according to any one of [1] to [5], comprising: a combustion device; and a heat exchanger heated by the exhaust generated by the burner, and having a hot water supply circuit for heating water supplied from the outside by the heat exchanger to supply hot water, and a heating circuit for radiating heat from a heat dissipation terminal.

[0019] <First Embodiment> The following description relates to the hot water heater 1 according to the first embodiment. 1. Overall Configuration of the Hot Water Heater 1 FIG. 1 is a schematic circuit diagram of a hot water heater 1 which is an example of a combustion device. The hot water heater 1 mainly includes a hot water supply circuit 2, a heating circuit 3, a bathtub circuit 4, etc., and is a device capable of performing hot water supply operation, automatic hot water filling operation, afterburning operation, heating operation, etc.

[0020] The hot water heater 1 is provided with a housing 1A configured as a metal casing inside the housing, and a first combustion system unit 5 and a second combustion system unit 6 are configured inside the housing 1A. The housing 1A is configured as, for example, a metal can body or a metal box body, and is configured to accommodate a hot water supply burner 8A, a heating burner 33A, a hot water supply side heat exchanger 7, a heating side heat exchanger 32, etc. The first combustion system unit 5 is a combustion system that performs gas combustion and water heating when the hot water supply circuit 2 performs a hot water supply operation. The second combustion system unit 6 is a combustion system that performs gas combustion and water heating during a heating operation or an afterburning operation.

[0021] The hot water supply circuit 2 is a circuit that heats water supplied from the outside of the hot water heater 1 by the hot water supply side heat exchanger 7 to supply hot water. The hot water supply circuit 2 includes the first combustion system unit 5, and specifically includes a plurality of hot water supply burners 8A and a hot water supply side heat exchanger 7. A hot water supply combustion chamber 5A is provided in the first combustion system unit 5, and a hot water supply side burner unit 8 and a hot water supply side heat exchanger 7 are provided in the hot water supply combustion chamber 5A. The hot water supply side burner unit 8 includes burner blocks 9A, 9B, and 9C, and each of the burner blocks 9A, 9B, and 9C includes a plurality of hot water supply burners 8A. Each of the plurality of hot water supply burners 8A is configured as a gas burner that burns gas.

[0022] The hot water supply side heat exchanger 7 is a heat exchanger heated by the exhaust gas generated by the hot water supply burner 8A. The hot water supply side heat exchanger 7 includes a hot water supply side first heat exchanger 7A and a hot water supply side second heat exchanger 7B. The hot water supply side first heat exchanger 7A has a plurality of fins 7Z. The first combustion system unit 5 is provided with the hot water supply side first heat exchanger 7A above the plurality of hot water supply burners 8A, and the hot water supply side second heat exchanger 7B is provided above the hot water supply side first heat exchanger 7A. A pipeline 7C is connected between the downstream end of the hot water supply side second heat exchanger 7B and the upstream end of the hot water supply side first heat exchanger 7A, and the hot water flowing through the hot water supply side second heat exchanger 7B flows through the pipeline 7C to the hot water supply side first heat exchanger 7A. The hot water supply side heat exchanger 7 heats the water passing through the inside by the exhaust gas (combustion exhaust gas) generated by burning gas with the plurality of hot water supply burners 8A. The hot water supply side first heat exchanger 7A recovers sensible heat from the combustion exhaust gas discharged from the hot water supply side burner unit 8, and the hot water supply side second heat exchanger 7B recovers latent heat from the combustion exhaust gas discharged from the hot water supply side burner unit 8.

[0023] The hot water supply circuit 2 further includes a water supply pipe 11, a control valve 13A, a water flow sensor 14, a hot water outlet pipe 10, a bypass pipe 12, a control valve 13B, a thermistor 15A (hot water inner cylinder thermistor), a thermistor 15B (hot water outlet thermistor), and the like. The water supply pipe 11 is connected to the inlet of the hot water supply side heat exchanger 7. The water supply pipe 11 is connected to an external pipe, and is configured as a pipe that introduces tap water from, for example, a water supply and flows this tap water toward the upstream end (inlet) of the hot water supply side heat exchanger 7. The water flow sensor 14 is a sensor that detects the flow rate of the water flowing through the water supply pipe 11. The control valve 13A is a valve for controlling the flow rate of the water flowing through the water supply pipe 11, and is a valve that changes the opening degree of the water supply pipe 11 by control. The hot water outlet pipe 10 is connected to the downstream end (outlet) of the hot water supply side heat exchanger 7. The hot water outlet pipe 10 is a pipe that flows the hot water heated by the hot water supply side heat exchanger 7. The hot water outlet pipe 10 forms a path for discharging the hot water heated by the hot water supply side heat exchanger 7 to the outside of the appliance.

[0024] A bypass pipe 12 is connected between the water supply pipe 11 and the hot water outlet pipe 10 so as to bypass the hot water supply side heat exchanger 7. A control valve 13B (bypass control valve) is provided in the bypass pipe 12. The control valve 13B is a valve for controlling the flow rate of the water flowing through the bypass pipe 12, and is specifically configured as a valve that changes the opening degree of the bypass pipe 12 by control. A thermistor 15A is provided upstream of the connection portion of the bypass pipe 12 in the hot water outlet pipe 10. The thermistor 15A detects the temperature of the hot water discharged from the hot water supply side heat exchanger 7, and specifically detects the hot water temperature near the outlet of the first heat exchanger 7A on the hot water supply side. A thermistor 15B is provided downstream of the connection portion of the bypass pipe 12. The thermistor 15B detects the hot water outlet temperature after mixing of the water from the bypass pipe 12, and specifically detects the temperature of the hot water supplied downstream of the confluence point of the bypass pipe 12 in the hot water outlet pipe 10. The temperatures of the hot water detected by these thermistors 15A and 15B are input to a control device 70 described later.

[0025] The hot water supply circuit 2 further includes a gas pipe 16, a main gas solenoid valve 17, a gas proportional valve 18, and a solenoid valve 19. The gas pipe 16 is a pipe through which gas supplied from outside the hot water supply and heating apparatus 1 via a gas inlet passes, and forms a path for supplying gas to the hot water supply burner 8A. The main gas solenoid valve 17 is provided upstream of the gas pipe 16, and the gas proportional valve 18 is provided downstream of the main gas solenoid valve 17. The downstream side of the gas proportional valve 18 (hot water supply gas proportional valve) in the gas pipe 16 branches, and branch pipes 16A to each of the burner blocks 9A, 9B, 9C and branch pipes 16B to each of the burner blocks 34A, 34B are provided. Each branch pipe 16A is provided with a solenoid valve 19. The solenoid valve 19 (hot water supply switching solenoid valve) switches the branch pipe 16A between an open state (suppliable state) and a closed state (shut-off state), and the supply and shut-off of fuel gas to each of the burner blocks 9A, 9B, 9C are individually switched by the respective solenoid valves 19. By switching the solenoid valve 19, the combustion range of the hot water supply side burner unit 8 is switched, and each combustion range is associated as a stage number.

[0026] The hot water supply circuit 2 further includes a fan 20. The fan 20 is provided below the hot water supply combustion chamber 5A. By the operation of the fan 20, combustion air is supplied to each of the hot water supply burners 8A and the heating burner 33A, and combustion exhaust gas discharged from the hot water supply side burner unit 8 and the heating side burner unit 33 is discharged from the exhaust port 90. The hot water supply circuit 2 is also provided with an igniter for ignition, an ignition electrode, a hot water supply flame rod, and the like.

[0027] The bath circuit 4 includes a bath circulation path 63 and a bath heat exchanger 50. The bath circulation path 63 forms a flow path configured to circulate the hot water derived from an external bathtub 52 and introduce it into the bathtub 52. The bath heat exchanger 50 is configured as a liquid-liquid heat exchanger that performs heat exchange between the heat medium flowing through the bath heating pipe 51 and the hot water flowing through the bath circulation path 63.

[0028] The bathtub heat exchanger 50 is provided with a pipe 50A that forms part of the bathtub circulation path 63, and the bathtub heating pipe 51 is arranged inside the pipe 50A. The bathtub circulation path 63 is configured to include the pipe 50A, the bathtub supply pipe 53, and the bathtub return pipe 54. When the bathtub circulation pump 55 operates, the bathtub circulation path 63 functions as a flow path for drawing out hot water from the bathtub 52 provided outside the water heater 1, and functions as a flow path for circulating the drawn-out hot water and introducing it into the bathtub 52. The bathtub return pipe 54 is provided with a bathtub circulation pump 55 that causes the hot water in the bathtub return pipe 54 to flow in a predetermined direction, and a water flow switch 57 that detects that hot water with a flow rate equal to or greater than a predetermined value is flowing through the bathtub return pipe 54. The bathtub return pipe 54 is provided between the bathtub 52 outside the appliance and the pipe 50A, and forms a flow path for flowing hot water from the bathtub 52 to the pipe 50A when the bathtub circulation pump 55 operates. The bathtub supply pipe 53 is provided between the pipe 50A and the bathtub 52, and forms a flow path for flowing hot water from the pipe 50A to the bathtub 52 when the bathtub circulation pump 55 operates. The bathtub supply pipe 53 is provided with a bathtub supply thermistor 64 that detects the temperature of the hot water flowing out of the bathtub heat exchanger 50 into the bathtub 52. The bathtub return pipe 54 is provided with a bathtub return thermistor 65 that detects the temperature of the hot water flowing into the bathtub return pipe 54 from the bathtub 52.

[0029] A drop pipe 59 is connected to the bathtub return pipe 54 in a configuration branched from the hot water outlet pipe 10. The drop pipe 59 communicates with the bathtub return pipe 54. The drop pipe 59 is provided with a hot water supply solenoid valve 60, a drop water volume sensor 61, a plurality of check valves 62, and the like. When the hot water supply solenoid valve 60 provided in the drop pipe 59 is opened during the operation of the hot water supply circuit 2, the hot water heated by the hot water supply circuit 2 is supplied to the bathtub 52 through the drop pipe 59.

[0030] The heating circuit 3 is a circuit that can heat the heat medium by the heating-side heat exchanger 32 and supply the heat medium to the heating terminal (heat dissipation terminal) via the heat medium circulation path 48. In the present embodiment, the heat medium is, for example, hot water. Note that, as the heat medium, a fluid other than hot water may be used. The heating circuit 3 includes a second combustion system unit 6 and a heat medium circulation path 48. The second combustion system unit 6 is provided with a heating combustion chamber 6A, and a heating-side burner unit 33 and a heating-side heat exchanger 32 are provided in the heating combustion chamber 6A. The heating combustion chamber 6A is partitioned from the hot water supply combustion chamber 5A by a partition member 80 in the housing 1A, and a temperature sensor 82 for detecting the temperature of the heating combustion chamber 6A is provided on the partition member 80.

[0031] The heating-side burner unit 33 includes burner blocks 34A and 34B, and each of the burner blocks 34A and 34B includes a plurality of heating burners 33A. Each of the plurality of heating burners 33A is configured as a gas burner that burns gas.

[0032] The heating-side heat exchanger 32 is a heat exchanger heated by the exhaust gas generated by the heating burner 33A. Specifically, it is a device that acts to heat the heat medium passing through its interior by the combustion exhaust gas of the heating burner 33A. The heating-side heat exchanger 32 includes a heating-side first heat exchanger 32A and a heating-side second heat exchanger 32B. The heating-side first heat exchanger 32A has a plurality of fins 32Z. The second combustion system section 6 has the heating-side first heat exchanger 32A provided above a plurality of heating burners 33A, and the heating-side second heat exchanger 32B provided above the heating-side first heat exchanger 32A. The heating-side heat exchanger 32 heats the heat medium passing through its interior by the exhaust gas (combustion exhaust gas) generated by burning gas with a plurality of heating burners 33A. The heating-side first heat exchanger 32A is supplied with the exhaust gas (combustion exhaust gas) generated by burning gas with the heating burner 33A (gas burner), and functions to heat the heat medium passing through the heating-side first heat exchanger 32A by the heat of this combustion exhaust gas. The heating-side first heat exchanger 32A recovers sensible heat from the combustion exhaust gas discharged from the heating-side burner unit 33. The heating-side second heat exchanger 32B is supplied with the gas after the combustion exhaust gas has passed through the heating-side first heat exchanger 32A, and functions to heat the heat medium passing through the heating-side second heat exchanger 32B by this gas. The heating-side second heat exchanger 32B recovers latent heat from the combustion exhaust gas discharged from the heating-side burner unit 33.

[0033] The heat medium circulation path 48 is a path for circulating the heat medium so as to pass through the heating-side heat exchanger 32, forming the flow path of the heat medium. The heat medium circulation path 48 includes a common forward flow path 38K as the heating forward pipe, a first internal flow path 38A as the heating high-temperature forward pipe, a second internal flow path 38B as the heating low-temperature forward pipe, and a common return flow path 38C as the heating return pipe.

[0034] When the first heat dissipation terminal 39A as a heating terminal is connected as shown in Fig. 1, the heat medium circulation path 48 is configured such that the heat medium circulates through the common forward flow path 38K, the first internal flow path 38A, the first terminal flow path 38G of the first heat dissipation terminal 39A, and the common return flow path 38C. When the second heat dissipation terminal 39Z as a heating terminal is connected as shown in Fig. 1, the heat medium circulation path 48 is configured such that the heat medium circulates through the common forward flow path 38K, the second internal flow path 38B, the second terminal flow path 38H of the second heat dissipation terminal 39Z, and the common return flow path 38C.

[0035] The first internal flow path 38A is connected to the first heat dissipation terminal 39A as a flow path so as to communicate with the first terminal flow path 38G provided outside the hot water heater 1. The first internal flow path 38A is configured as a flow path branching from the branch portion 38J, and is configured as a flow path for flowing the heat medium from the branch portion 38J to the first heat dissipation terminal 39A. A part of the first internal flow path 38A is provided in the first heat exchanger 32A on the heating side, and the heat medium flowing through the first internal flow path 38A is configured to be heated in the first heat exchanger 32A on the heating side.

[0036] The second internal flow path 38B is connected to the second heat dissipation terminal 39Z as a flow path so as to communicate with the second terminal flow path 38H provided outside the hot water heater 1. The second internal flow path 38B is configured as a flow path branching from the branch portion 38J, and is configured as a flow path for flowing the heat medium from the branch portion 38J to the second heat dissipation terminal 39Z.

[0037] The heating circuit 3 further includes an expansion tank 36, a heating circulation pump 37, a heating high-temperature thermistor 40, and a heating low-temperature thermistor 41. The common return flow path 38C is a flow path through which the heat medium flowing into the inflow portion 35A returns to the expansion tank 36. In the example of FIG. 1, the upstream end of the common return flow path 38C is the inflow portion 35A, and the downstream end of the common return flow path 38C is connected to the inlet portion 36C of the expansion tank 36. The common return flow path 38C is configured as a pipe that introduces the heat medium exiting from the first heat dissipation terminal 39A and the heat medium exiting from the second heat dissipation terminal 39Z into the interior through the inflow portion 35A and causes it to flow through the heating-side heat exchanger 32 (heating-side second heat exchanger 32B). The common return flow path 38C is configured to communicate with the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z, and is connected to the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z as a flow path for flowing the heat medium.

[0038] An intermediate pipe 38D and an intermediate pipe 38E are provided between the outlet of the heating-side second heat exchanger 32B and the inlet of the heating-side first heat exchanger 32A. In the paths of the intermediate pipes 38D and 38E, the expansion tank 36 and the heating circulation pump 37 are provided, and the heat medium can flow from the heating-side second heat exchanger 32B to the heating-side first heat exchanger 32A through the intermediate pipe 38D, the expansion tank 36, and the intermediate pipe 38E. The intermediate pipe 38D is a part of the common return flow path 38C and is a flow path between the outlet of the heating-side second heat exchanger 32B and the inlet portion 36C of the expansion tank 36. The intermediate pipe 38E is a pipe constituted by a part of the common forward flow path 38K and the first internal flow path 38A, and is provided between the outlet portion 36B of the expansion tank 36 and the inlet of the heating-side first heat exchanger 32A.

[0039] The common forward flow path 38K is configured as a flow path that introduces the heat medium flowing out from the outlet portion 36B and flows the heat medium flowing out from the expansion tank 36. A heating circulation pump 37 is provided in the middle of the common forward flow path 38K. The heating circulation pump 37 causes the heat medium in the common forward flow path 38K to flow from the expansion tank 36 side to the branch portion 38J side.

[0040] The second internal flow path 38B is provided in a configuration where a plurality of internal branch paths 38F branch off. A second valve 39G is provided in each internal branch path 38F as a valve for opening and closing each branch path 39F. In the example of FIG. 1, one internal branch path 38F communicates with the second heat radiation terminal 39Z and is connected to the second heat radiation terminal 39Z outside the appliance. The downstream sides of the first heat radiation terminal 39A and the second heat radiation terminal 39Z communicate with a common return flow path 38C. The first heat radiation terminal 39A is, for example, a high-temperature heating terminal such as a heating blower that blows warm air into a bathroom or a dressing room. The second heat radiation terminal 39Z is, for example, a low-temperature heating terminal such as floor heating in a dressing room.

[0041] The heating high-temperature thermistor 40 is provided in the first internal flow path 38A on the outlet side of the heating-side heat exchanger 32, and detects the temperature of the heat medium flowing out from the heating-side heat exchanger 32 (specifically, the heat medium flowing out from the first heating-side heat exchanger 32A). The temperature detected by the heating high-temperature thermistor 40 corresponds to the temperature of the heat medium flowing into the first heat radiation terminal 39A during the circulation of the heat medium passing through the first heat radiation terminal 39A. The heating low-temperature thermistor 41 is provided in the expansion tank 36. The temperature detected by the heating low-temperature thermistor 41 corresponds to the temperature of the heat medium flowing into the second heat radiation terminal 39Z during the circulation of the heat medium passing through the second heat radiation terminal 39Z.

[0042] The heating circuit 3 includes a plurality of branch pipes 16B and a plurality of heating switching solenoid valves 44. As described above, the branch pipe 16B is provided in a configuration branched from the gas pipe 16 to the heating circuit 3 side. Each heating switching solenoid valve 44 is provided in each branch pipe 16B. The heating switching solenoid valve 44 is configured to switch the branch pipe 16B in which it is provided between an open state (supply possible state) and a closed state (cut-off state). The supply and cut-off of the fuel gas to each of the burner blocks 34A, 34B are individually switched by each heating switching solenoid valve 44. By switching the heating switching solenoid valve 44, the combustion range of the heating-side burner unit 33 is switched, and each combustion range is associated as a stage number. Note that the heating circuit 3 is also provided with an ignition electrode, a heating frame rod, and the like.

[0043] In the heating circuit 3, hot water heated by the heating-side heat exchanger 32 circulates through the heat medium circulation path 48 due to the operation of the heating circulation pump 37. Specifically, in the heating circuit 3, when the heating circulation pump 37 operates, the hot water flowing through the heat medium circulation path 48 is heated by the combustion exhaust gas discharged from the heating-side burner unit 33 in the heating-side heat exchanger 32, and circulates through the common return flow path 38C, the first internal flow path 38A, and the first heat dissipation terminal 39A, and also circulates through the common return flow path 38C, the second internal flow path 38B, and the second heat dissipation terminal 39Z. In the example of FIG. 1, hot water is supplied to the first heat dissipation terminal 39A according to the operation of the first valve 39H which is a built-in thermostatic valve. The second heat dissipation terminal 39Z is configured as a low-temperature heating terminal, and hot water is supplied to the second heat dissipation terminal 39Z according to the operation of the second valve 39G which is a thermostatic valve inside the appliance.

[0044] As shown in FIG. 1, the bath heating pipe 51 is provided in a configuration branched from the first internal flow path 38A. The bath heating pipe 51 branches from a position downstream of the heating-side heat exchanger 32 in the heat medium circulation path 48 (specifically, downstream of the heating-side first heat exchanger 32A), and forms a flow path for guiding the heat medium flowing through the heat medium circulation path 48 to the bath heat exchanger 50 side. The bath heating pipe 51 is connected between the first internal flow path 38A and the common return flow path 38C so as to communicate with each other.

[0045] The control valve 58 is a valve provided upstream of the bath heat exchanger 50 in the bath heating pipe 51. The control valve 58 is configured to open and close the bath heating pipe 51, and is configured to switch between a closed state in which the water flow passing through itself in the bath heating pipe 51 is blocked, and an open state in which the water flow passing through itself in the bath heating pipe 51 is allowed. The control valve 58 has a switch. This switch is configured as a limit switch, and enters a first state in which a predetermined first signal (for example, an on signal) is output when the control valve 58 is in the fully open state where it is most open, and enters a second state in which a second signal (for example, an off signal) different from the first signal is output when the control valve 58 is in the fully closed state where it is blocked.

[0046] The hot water supply and heating machine 1 further includes a control device 70, a hot water supply remote controller 71, a bath remote controller 72, a heating remote controller 73, and a room temperature thermistor (not shown). The control device 70 corresponds to an example of a control unit and is an electronic control device including an information processing device such as a CPU, a memory such as a semiconductor memory device, an interface circuit, etc., and functions as a controller for performing various controls. Various programs, data tables, set values, etc. are stored in the memory. The control device 70 is configured to be able to acquire signals from various sensors and switches (thermistors, water volume sensors, switches, etc.) and controls a hot water supply circuit 2, a heating circuit 3, a bath circuit 4, etc. The room temperature thermistor is provided, for example, in the dressing room as a means for detecting the temperature in the dressing room. Note that the control device 70 may be constituted by a single device (for example, a controller configured as a single unit) or may be constituted by a plurality of devices.

[0047] 2. Basic operation of the hot water supply and heating machine 1 (Normal hot water supply operation) When a hot water supply faucet provided outside the apparatus to communicate with the hot water outlet pipe 10 is opened and water flows into the apparatus, and the water volume sensor 14 outputs a signal indicating the flow of water, the control device 70 rotates the fan 20 for a predetermined time to discharge the combustion exhaust gas stored in the hot water supply combustion chamber 5A (purging). Thereafter, the control device 70 opens the main gas solenoid valve 17 of the gas pipe 16 and each solenoid valve 19, and opens the gas proportional valve 18 at a predetermined opening degree to control the supply of gas to each hot water supply burner 8A, and operates the igniter to ignite the hot water supply burner 8A. When gas is burned by the hot water supply burner 8A by such control, the water passing through the hot water supply side heat exchanger 7 is heated by the combustion exhaust gas generated by the combustion and a hot water outlet operation is performed so that the water flows to the hot water outlet pipe 10, and the heated hot water is discharged from the hot water supply faucet.

[0048] During the above hot water discharging operation, the control device 70 monitors the hot water temperature detected by the thermistor 15B provided in the hot water discharge pipe 10, and controls the opening and closing of the solenoid valve 19 and adjusts the opening degree of the gas proportional valve 18 so that the hot water temperature becomes the set temperature indicated by the hot water supply remote controller 71 or the bath remote controller 72. At the same time, the control device 70 continuously changes the air volume by controlling the rotation speed of the fan 20. When the hot water supply faucet is closed during the above hot water discharging operation and the signal output by the water volume sensor 14 indicates a water flow stop state, the control device 70 closes the original gas solenoid valve 17 and the solenoid valve 19 to extinguish the hot water supply burner 8A, and rotates the fan 20 for a predetermined time to perform post-purge.

[0049] (Automatic hot water filling operation) The control device 70 can perform control to automatically fill the bathtub 52 with hot water. For example, when the hot water filling switch provided on the hot water supply remote controller 71 or the bath remote controller 72 is pressed, the control device 70 sets the hot water temperature to the hot water filling temperature set by the hot water supply remote controller 71 or the bath remote controller 72 as the target temperature (for example, 40 ° C) and starts hot water filling. Specifically, the control device 70 opens the hot water supply solenoid valve 60 in the drop pipe 59 to put the hot water supply circuit 2 into a water flow state, and burns the hot water supply burner 8A so that the heated hot water flows into the hot water discharge pipe 10. The hot water flowing through the hot water discharge pipe 10 in this way is supplied to the bathtub 52 through the drop pipe 59 and the bath return pipe 54.

[0050] After the control device 70 starts supplying hot water to the bathtub 52 in this way, the control device 70 monitors whether the water volume detected by the drop water volume sensor 61 provided in the drop pipe 59 (the total water volume since the start of automatic hot water filling) has reached the set water volume. When it is confirmed that the set water volume has been reached, the control device 70 closes the hot water supply solenoid valve 60 to stop the water flow, extinguishes the hot water supply burner 8A, and ends the hot water filling. After that, the control device 70 operates the bath circulation pump 55 to circulate the hot water in the bathtub 52 in the bath circuit 4. When the control device 70 finishes hot water filling, the control device 70 notifies the hot water supply remote controller 71 or the bath remote controller 72 of the end of hot water filling.

[0051] (Automatic reheating operation) The control device 70 can perform control to automatically reheat (boil up) the water stored in the bathtub 52. For example, when the reheat switch provided on the hot water supply remote control 71 or the bath remote control 72 is pressed, the control device 70 sets the reheat temperature to the target temperature (e.g., 40 °C) set on the hot water supply remote control 71 or the bath remote control 72 and starts the reheat. Specifically, the control device 70 ignites the heating burner 33A, opens the control valve 58, operates the bath circulation pump 55, and performs reheat by heating with the bath heat exchanger 50 while circulating the hot water in the bathtub 52. After starting such reheat, the control device 70 monitors whether the hot water temperature detected by the bath return thermistor 65 has reached the target temperature. When it is confirmed that the temperature has reached, the control device 70 extinguishes the heating burner 33A, stops the bath circulation pump 55, and ends the reheat. When the control device 70 ends the reheat, it notifies the hot water supply remote control 71 or the bath remote control 72 of the end of the reheat.

[0052] 3. Configuration for supplying heat medium to the first heat dissipation terminal 39A (high-temperature heating terminal) and the second heat dissipation terminal 39Z (low-temperature heating terminal) The hot water supply and heating machine 1 constitutes a hot water supply system while being connected to the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z, and supplies the heat medium branched by the internal branched flow path to the external first heat dissipation terminal 39A and the second heat dissipation terminal 39Z.

[0053] As shown in FIG. 1, the downstream end of the common flow path 38K in the heat medium circulation path 48 is a branch portion 38J. The branch portion 38J is a portion that branches the flow of the heat medium flowing through the common flow path 38K. The upstream side of the branch portion 38J is the common flow path 38K, and the downstream side of the branch portion 38J branches into a first internal flow path 38A and a second internal flow path 38B. The first internal flow path 38A has a reheat branch portion 56 that branches into the bath circuit 4. On the bath circuit 4 side branched by the reheat branch portion 56, the bath heating pipe 51 passes through the bath heat exchanger 50 and is connected to the common return flow path 38C. The lower side (downstream side) of the reheat branch portion 56 has a connection portion 46B that branches into the bypass flow path 46.

[0054] The bypass flow path 46 is provided between the common return flow path 38C and the first internal flow path 38A. The bypass flow path 46 is a path through which the heat medium can flow so as to bypass between the common return flow path 38C and the first internal flow path 38A.

[0055] The downstream end of the first internal flow path 38A is configured as a first outflow portion 35B that can be connected to the outside and through which the heat medium flows out. The first outflow portion 35B is provided at the downstream end of the first internal flow path 38A and is configured as an outlet for flowing out the heat medium from the first internal flow path 38A toward the first terminal flow path 38G. The downstream end of the second internal flow path 38B is configured as a second outflow portion 35C that can be connected to the outside and through which the heat medium flows out. The second outflow portion 35C is provided at the downstream end of the second internal flow path 38B and is configured as an outlet for flowing out the heat medium from the second internal flow path 38B toward the second terminal flow path 38H. The upstream end of the common return flow path 38C is configured as an inflow portion 35A that can be connected to the outside and through which the heat medium flows in. The inflow portion 35A is provided on the downstream side of the first terminal flow path 38G and on the downstream side of the second terminal flow path 38H, and is an inlet through which the heat medium flowing through the first terminal flow path 38G flows in, and is also an inlet through which the heat medium flowing through the second terminal flow path 38H flows in.

[0056] Outside the hot water heating apparatus 1, a first heat radiation terminal 39A and a second heat radiation terminal 39Z are provided, to which the heat medium is supplied from the hot water heating apparatus 1 and which communicate with the heat medium circulation path 48. The first heat radiation terminal 39A has a first terminal flow path 38G through which the heat medium flows, and radiates the heat of the heat medium flowing through the first terminal flow path 38G. In the space near the first heat radiation terminal 39A, the air is heated by the heat of the heat medium flowing through the first terminal flow path 38G being radiated. The first heat radiation terminal 39A is configured as a high-temperature heating terminal. The second heat radiation terminal 39Z has a second terminal flow path 38H through which the heat medium flows, and radiates the heat of the heat medium flowing through the second terminal flow path 38H. In the space near the second heat radiation terminal 39Z, the air is heated by the heat of the heat medium flowing through the second terminal flow path 38H being radiated. The downstream end of the first terminal flow path 38G and the downstream end of the second terminal flow path 38H are connectable so as to communicate with the inflow portion 35A of the hot water heating apparatus 1.

[0057] The supply of the heat medium to the first terminal flow path 38G is switched between a state of blocking the supply of the heat medium and a state of permitting it by opening and closing the first valve 39H. When the first valve 39H is open, it is permitted for the heat medium to pass through the first valve 39H, and it is permitted for the heat medium to flow from inside the first internal flow path 38A, through the first terminal flow path 38G, and to the downstream side (inflow portion 35A side) of the first valve 39H. When the first valve 39H is closed, it is blocked for the heat medium to pass through the first valve 39H, and no heat medium flows from inside the first internal flow path 38A to the downstream side of the first valve 39H. The supply of the heat medium to the second terminal flow path 38H is switched between a state of blocking the supply of the heat medium and a state of permitting it by opening and closing the second valve 39G. When the second valve 39G is open, it is permitted for the heat medium to pass through the second valve 39G, and it is permitted for the heat medium to flow from inside the second internal flow path 38B, through the second terminal flow path 38H, and to the downstream side (inflow portion 35A side) of the second valve 39G. When the second valve 39G is closed, it is blocked for the heat medium to pass through the second valve 39G, and no heat medium flows from inside the second internal flow path 38B to the downstream side of the second valve 39G. Both the first valve 39H and the second valve 39G are thermostatic valves. A thermostatic valve, for example, expands an expansion body with the heat of a heating element (Positive Temperature Coefficient) when the power is turned on, pushes a piston to open the valve so that hot and cold water can flow, and when the power is turned off, the heating element naturally dissipates heat to contract the expansion body and close the valve.

[0058] The heat medium that has flowed into the inflow portion 35A circulates through the heat medium circulation path 48 in the water heater 1. Specifically, the heat medium flows downstream from the inflow portion 35A through the common return flow path 38C, is heated by the heating-side second heat exchanger 32B, then passes through the expansion tank 36, and is further moved downstream by the power of the heating circulation pump 37. Then, the heat medium that has flowed toward the branch portion 38J is divided at the branch portion 38J into the heat medium heading toward the first internal flow path 38A and the heat medium heading toward the second internal flow path 38B. The heat medium flowing through the first internal flow path 38A is heated by the heating-side first heat exchanger 32A on the way.

[0059] The heat medium flowing through the first internal flow path 38A flows out toward the first terminal flow path 38G with the first outflow portion 35B as the outlet. The heat medium flowing through the second internal flow path 38B flows out toward the second terminal flow path 38H with the second outflow portion 35C as the outlet.

[0060] The first valve 39H that opens and closes the first terminal flow path 38G, the second valve 39G that opens and closes the second internal flow path 38B, and the heating circulation pump 37 are controlled by the control device 70. The control device 70 is electrically connected to each of the first valve 39H, the second valve 39G, and the heating circulation pump 37, and performs opening and closing control of the first valve 39H and the second valve 39G and drive control of the heating circulation pump 37.

[0061] 4. Configuration for controlling ignition according to wind speed The water heater 1 includes a spark plug 85, which is an example of ignition means, and a flame sensor 86 inside the housing 1A. The spark plug 85 ignites the combustion gas by generating a spark discharge in response to an input signal from the control device 70. The control device 70 controls the opening degree of the gas proportional valve 18 and the opening and closing of the electromagnetic valves 19, 44 to supply fuel gas to the burners 8A, 33A while adjusting the gas supply amount. When the fuel gas ignites, combustion in the burners 8A, 33A starts, and the flame generated by the combustion is detected by the flame sensor 86. The detection signal of the flame sensor 86 is output to the control device 70, and the control device 70 detects combustion when it receives the detection signal from the flame sensor 86.

[0062] The fan 20 operates to supply air into the container 1A. The fan 20 has a rotating body 20B that generates wind by its rotation and a drive source 20A that rotates the rotating body 20B, and is configured such that the rotational speed of the rotating body 20B increases as the current applied to the drive source 20A increases. The fan 20 may be a sirocco fan, a propeller fan, or other fans. The rotating body 20B is, for example, a rotating body 20B that has blades and the air volume increases as its rotational speed increases. The drive source 20A is, for example, a motor that rotates the rotating body 20B, and may be a DC motor or an AC motor. The control device 70 functions as a fan control device that controls the rotation of the fan 20. More specifically, the control device 70 includes a drive circuit that controls the current applied to the drive source 20A, and can perform feedback control to increase or decrease the current applied to the drive source 20A so that the rotational speed of the fan 20 approaches the target rotational speed based on the deviation between the target rotational speed and the current rotational speed. The feedback control may be PID control, PI control, or other control.

[0063] In the vicinity of the fan 20, a rotation speed sensor 76 that detects the rotation speed (rotational speed) of the fan 20 and a current sensor 75 that detects the drive current of the fan 20 are provided. The rotation speed sensor 76 is provided at a position adjacent to the rotating body 20B, and for example, a magnetic sensor equipped with a Hall element is used. Note that the rotation speed sensor 76 is not limited to this, and an optical or mechanical sensor may be used. The current sensor 75 is provided in the supply path of the drive current to the drive source 20A as a motor, and detects the current supplied to the drive source 20A. The current sensor 75 may be any sensor that can detect the value of the current supplied to the drive source 20A. For example, a current sensor with a core that measures the magnitude of the magnetic field generated in the core or a coreless current sensor that measures the current using the Hall effect can be used. Also, it is not limited to the magnetic field type, and for example, a current sensor using a shunt resistor or other known current sensors may be used.

[0064] A signal corresponding to the drive current of the fan 20 detected by the current sensor 75 and a signal corresponding to the rotational speed of the fan 20 detected by the rotational speed sensor 76 are output to the control device 70. The control device 70 grasps the current supplied to the drive source 20A based on the signal given from the current sensor 75, and grasps the rotational speed of the fan 20 based on the signal given from the rotational speed sensor 76.

[0065] When the hot water supply circuit 2 performs a hot water supply operation, the control device 70 calculates the required combustion amount required by the hot water supply side burner unit 8 according to the temperature of the hot water detected by the thermistors 40 and 41, and so that the obtained required combustion amount is obtained, the opening degree of the gas proportional valve 18 and the opening and closing of the hot water supply side solenoid valve 19 are controlled to adjust the gas supply amount. The fan 20 controls the target rotational speed so that the supply amount of combustion air corresponds to the gas supply amount. When controlling the fan 20 to rotate at the target rotational speed, if wind is blown from the outside to the exhaust port 90 of the combustion gas, a load corresponding to the wind speed of the wind is generated on the fan 20 and the rotational speed fluctuates. Therefore, the control device 70 increases or decreases the drive current by feedback control (such as PID control or PI control) so that the rotational speed of the fan 20 becomes the target rotational speed according to the load. The exhaust port 90 is arranged outside the housing of the hot water supply and heating machine 1, and is arranged, for example, outdoors (for example, outside the house).

[0066] 5. Control at ignition When a predetermined start condition is satisfied, the control device 70 starts the control of FIG. 2. The predetermined start condition may be, for example, that the power supply of the hot water supply and heating machine 1 is turned on, or may be other conditions. When the control device 70 starts the process of FIG. 2 with the establishment of the above start condition, at step S11, it is determined whether the condition for operating the hot water supply circuit 2 or the heating circuit 3 is satisfied (that is, whether the condition for burning the burner 8A or the burner 33A is satisfied). The condition for operating the hot water supply circuit or the heating circuit may be "for example, a predetermined operation is performed on the hot water supply remote controller 71 or the heating remote controller 73", or may be other conditions.

[0067] When the control device 70 determines that the condition for operating the hot water supply circuit 2 or the heating circuit 3 is not satisfied in step S11, that is, when the answer in step S11 is No, the determination in step S11 is repeated. When the control device 70 determines that the condition for operating the hot water supply circuit 2 or the heating circuit 3 is satisfied in step S11, that is, when the answer in S11 is Yes, the process proceeds to step S12 and the fan 20 is driven.

[0068] The control device 70 controls the fan 20 to rotate at the first rotational speed X1 [rpm] in step S12. The "control to rotate the fan 20 at the first rotational speed X1 [rpm]" started by the control device 70 in step S12 is an example of the first preliminary operation. The first rotational speed X1 is stored in the memory in advance, for example. The control device 70 monitors the rotational speed and the value of the current while receiving a signal for specifying the rotational speed of the fan 20 (the rotational speed of the rotating body 20B) from the rotational speed sensor 76 and receiving a signal for specifying the value of the current supplied to the drive source 20A from the current sensor 75, and controls the fan 20 to rotate at the first rotational speed X1 [rpm]. Specifically, the control device 70 calculates the difference between the target rotational speed and the current rotational speed (the detected value of the rotational speed sensor) of the fan 20 for each control cycle, and performs feedback control (for example, PID control) by a known method to increase or decrease the drive current of the fan 20 according to this difference.

[0069] After starting the control to rotate the fan 20 at the first rotational speed X1 [rpm] in step S12, the control device 70 determines in step S13 whether the current wind speed Y (the wind speed of the wind blowing at the exhaust port 90) is equal to or higher than the first wind speed Y1 [m / s]. Note that after step S12, the timing for making the determination in step S13 may be immediately after the fan 20 reaches the first rotational speed X1, or may be after a certain period of time has elapsed after the fan 20 reaches the first rotational speed X1. The case where the wind speed Y of the wind blowing at the exhaust port 90 is equal to or higher than the first wind speed Y1 is the case where the wind pressure applied from the outside into the exhaust port 90 is equal to or higher than the first value.

[0070] In the hot water supply and heating machine 1, there is a correlation among the value of the current supplied to the drive source 20A, the rotation speed of the rotating body 20B, and the wind speed of the wind blowing out of the exhaust port 90. When the value of the current and the rotation speed are specified, the value indicating the wind speed of the wind blowing out of the exhaust port 90 can be specified. The information for specifying the wind speed of the wind blowing out of the exhaust port 90 based on the value of the current and the rotation speed may be an arithmetic expression for calculating the "value indicating the wind speed" with the value of the current and the rotation speed as variables, or may be a table for determining the "value indicating the wind speed" according to the combination of the value of the current and the rotation speed. In the present embodiment, a correction coefficient is used as the value indicating the wind speed. The value of the correction coefficient corresponds to the wind speed of the wind blowing out of the exhaust port 90. The smaller the value of the correction coefficient, the greater the wind speed of the wind blowing out of the exhaust port 90. The correspondence between the correction coefficient and the wind speed is specified by a correspondence table or a function of the correspondence relationship that defines the correspondence between the correction coefficient and the wind speed such that the wind speed of the wind blowing out of the exhaust port 90 increases as the correction coefficient decreases. Once the correction coefficient is specified, the wind speed of the wind blowing out of the exhaust port 90 can be specified. For example, at the same rotation speed, the larger the current value (the larger the wind speed), the smaller the numerical value of the correction coefficient, and at the same rotation speed, the smaller the current value (the smaller the wind speed), the larger the numerical value of the correction coefficient. Also, at the same current value, the larger the rotation speed (the smaller the wind speed), the larger the numerical value of the correction coefficient, and at the same current value, the smaller the rotation speed (the larger the wind speed), the smaller the numerical value of the correction coefficient. The control device 70 specifies the value (correction coefficient) indicating the wind speed with the value of the current and the rotation speed as variables. When the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S13 is equal to or higher than the first wind speed Y1, the process proceeds to step S14. When the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S13 is less than the first wind speed Y1, the process proceeds to step S23. In the example of FIG. 2, Y1 = 15 [m / s], but it is not limited to this value, and the wind speed Y serving as the threshold value can be appropriately changed according to the installation location and the like.

[0071] When the control device 70 determines in step S13 that the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S13 is less than the first wind speed Y1, the process proceeds to step S23. In step S23, while rotating the fan 20 at the normal rotation speed which is an example of a predetermined rotation speed, the ignition plug 85 is caused to perform an ignition operation. When the condition for operating the hot water supply circuit 2 is satisfied in step S11 (when the condition for igniting the burner 8A is satisfied), the control device 70 ignites the ignition plug 85 on the burner 8A side in step S23 to burn the burner 8A. When the condition for operating the heating circuit 3 is satisfied in step S11 (when the condition for igniting the burner 33A is satisfied), the control device 70 ignites the ignition plug 85 on the burner 33A side in step S23 to burn the burner 8A. The normal rotation speed can be, for example, a rotation speed stored in advance in the memory of the control device 70, but is not limited thereto, and may be, for example, a rotation speed according to the determination result of the wind speed. The normal rotation speed may be smaller than the first rotation speed X1, may be about the same as the first rotation speed X1, or may be a rotation speed larger than the first rotation speed X1 and smaller than the second rotation speed X2.

[0072] When the control device 70 determines in step S13 that the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S13 is equal to or higher than the first wind speed Y1, the process proceeds to step S14. In step S14, it is determined whether the current wind speed Y (the wind speed of the wind blowing out of the exhaust port 90) is equal to or higher than the reference wind speed YB [m / s]. The reference wind speed YB is set to a wind speed that is greater than the first wind speed Y1 and less than the second wind speed Y2. The reference wind speed YB can be set to a wind speed that is less than the second wind speed Y2 within a range where it can be measured as a wind speed equivalent to the second wind speed Y2 due to measurement errors or the like. When the control device 70 determines in step S14 that the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S14 is less than the reference wind speed YB (when the determination in step S14 is No), the process proceeds to step S26. In step S26, while correcting the ignition rotation speed of the fan 20 to an ignition rotation speed higher than the normal rotation speed (a predetermined ignition rotation speed) using a correction coefficient, an ignition operation is performed on the ignition plug 85 to ignite the burner. When the control device 70 determines in step S14 that the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S14 is equal to or higher than the reference wind speed YB, the process proceeds to step S15, and the control device 70 controls the fan 20 to rotate at the second rotation speed X2 [rpm]. The second rotation speed X2 [rpm] is a rotation speed greater than the first rotation speed X1 [rpm]. The "control to rotate the fan 20 at the second rotation speed X2 [rpm]" started by the control device 70 in step S15 is an example of the second preliminary operation.

[0073] After the control device 70 starts the control to rotate the fan 20 at the second rotational speed X2 [rpm] in step S15, in step S16, it is determined whether or not a first fixed time (for example, 3 seconds) has elapsed since the start of rotation at the second rotational speed X2. The 3 seconds of the first fixed time is stored in the memory, for example. The first fixed time is not limited to 3 seconds and may be other values. After the control device 70 starts the control to rotate the fan 20 at the second rotational speed X2 [rpm] in step S15, until the first fixed time elapses, the control to rotate the fan 20 at the second rotational speed X2 [rpm] is continued while repeating the No determination in step S16. When the first fixed time (for example, 3 seconds) has elapsed after the control device 70 starts the control to rotate the fan 20 at the second rotational speed X2 [rpm] in step S15 (when Yes in step S16), the process proceeds to step S17.

[0074] When the control device 70 proceeds the process to step S17, it determines whether or not the rotational speed output from the rotational speed sensor 76 is stable in step S17. Specifically, when making the determination in step S17, the control device 70 determines whether or not the fluctuation range of the rotational speed of the fan 20 within a predetermined time T1 after becoming Yes in step S16 (for example, from before the predetermined time T1 at the time of this step S17 to the time of this step S17) is ±α% or less. "When the fluctuation range is ±α% or less within the immediately preceding predetermined time T1" means that when the wind speed at the start time of the predetermined time T1 is Xs, the maximum value of the rotational speed of the fan 20 within the predetermined time T1 is Xs×((100 + α) / 100) or less, and the minimum value of the rotational speed of the fan 20 within the predetermined time T1 is Xs×((100 - α) / 100) or more. That the fluctuation range is within ±α% is an example of the fluctuation range being within a predetermined value. The value of α is, for example, 5. The value of the predetermined time T1 is, for example, 2 seconds. The predetermined time T1 (for example, 2 seconds) is an example of the first specified period. The values of T1 and α are stored in the memory, for example. The above examples of T1 and α are merely examples, and they may be set to other values.

[0075] A decrease in the rotational speed can occur not only due to the external wind speed but also, for example, due to blockage of the exhaust port. However, in the case of blockage due to blockage of the exhaust port or the like, fluctuations (increase or decrease) in the rotational speed are less likely to occur. On the other hand, in the case of the external wind speed, since the wind speed and direction of the wind blowing against the exhaust port 90 can frequently change due to changes in the wind direction, etc., by determining the fluctuation range within a predetermined time T1, it is possible to detect whether or not the rotational speed of the fan 20 has changed due to the external wind.

[0076] When the control device 70 determines in step S17 that the fluctuation range of the rotational speed of the fan 20 within the predetermined time T1 immediately before step S17 is not ±α% or less (in the case of No in step S17), the process proceeds to step S24, and it is determined whether or not a second fixed time (for example, 30 seconds) has elapsed since the start in step S15 (the start of rotation at the second rotational speed X2). Note that the start of counting the second fixed time is not limited to this, and for example, the second fixed time may be counted at the start of any step from step S16 to step S17, or after a predetermined time has elapsed from any step. When the control device 70 determines in step S24 that the second fixed time (for example, 30 seconds of stable waiting time) has not elapsed since the start in step S15, the process returns to step S17, and again, in step S17, it is determined whether or not the fluctuation range of the rotational speed of the fan 20 within the predetermined time T1 immediately before step S17 is ±α% or less. When the control device 70 determines in step S24 that the second fixed time (for example, 30 seconds of stable waiting time) has elapsed since the start in step S15, an error is output and the ignition process is aborted.

[0077] As described above, after determining Yes in step S16, the control device 70 repeats the determination in step S17 (determination as to whether the fluctuation range of the rotation speed of the fan 20 within the immediately preceding predetermined time T1 is ±α% or less) until the second fixed time (for example, 30 seconds) elapses from the start in step S15, unless it determines Yes in step S17. If the fluctuation range of the rotation speed of the fan 20 within the immediately preceding predetermined time T1 does not become ±α% or less even after the second fixed time (for example, 30 seconds) elapses from the start in step S15 (Yes in step S24), it is highly likely that the exhaust port 90 is affected by external wind, and it is highly likely that it is not desirable to perform ignition. Therefore, an error is output and the ignition process is aborted. For example, if the fluctuation range of the rotation speed of the fan 20 within the predetermined time T1 does not become ±α% or less in a state where large fluctuations in wind speed constantly occur, such as on the rooftop of a high-rise building, an error is output and the ignition process is aborted. The error output in this case may be an audio output (buzzer sound or voice output of a message) indicating abnormality, an output that displays an error code or error message on a display device, or a data output that transmits information to an external device. The above second fixed time (stabilization waiting time) is stored in the memory, for example. In the above example, the second fixed time is 30 seconds, but other values may also be used.

[0078] When the control device 70 determines in step S17 that the fluctuation range of the rotation speed of the fan 20 within a predetermined time T1 immediately before step S17 is ±α% or less (when Yes in step S17), the process proceeds to step S18. In step S18, the control device 70 determines whether the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S18 is less than or equal to the second wind speed Y2 [m / s]. The second wind speed Y2 is a value greater than the first wind speed Y1 and the reference wind speed YB. The value of the second wind speed Y2 is stored in the memory, for example. In this embodiment, the second wind speed Y2 = 30 [m / s], but other values may also be used. The case where the wind speed Y of the wind blowing out of the exhaust port 90 is less than or equal to the second wind speed Y2 means the case where the wind pressure applied from the outside into the exhaust port 90 is less than or equal to the second value. The case where the wind speed Y of the wind blowing out of the exhaust port 90 is greater than the second wind speed Y2 means the case where the wind pressure applied from the outside into the exhaust port 90 is greater than the second value.

[0079] The control device 70 specifies the wind speed Y at the time of step S18 by, for example, the same method as in step S13. When it is determined in step S18 that the wind speed Y of the exhaust port 90 at the time of step S18 is less than or equal to the second wind speed Y2 [m / s] (when Yes in step S18), the process proceeds to step S26. In step S26, the ignition rotation speed of the fan 20 is corrected to an ignition rotation speed higher than the normal rotation speed (predetermined ignition rotation speed) using a correction coefficient, and an ignition operation is performed on the ignition plug 85 to ignite the burner.

[0080] In addition, in the above example, when the wind speed Y at the exhaust port 90 is equal to or less than the second wind speed Y2 [m / s] at the time of step S18, the control device 70 corrects the rotational speed of the fan 20 in step S26 to perform the ignition operation of the spark plug 85. However, the present invention is not limited to this example. For example, when the control device 70 determines that the wind speed Y at the exhaust port 90 is equal to or less than the first wind speed Y1 [m / s] at the time of step S18, the control device 70 may cause the spark plug 85 to perform the ignition operation while setting the ignition rotational speed of the fan 20 to the normal rotational speed (predetermined ignition rotational speed) in the same manner as in step S23 to ignite the burner. In this case, when the wind speed Y at the exhaust port 90 is greater than the first wind speed Y1 and equal to or less than the second wind speed Y2 [m / s] at the time of step S18, the control device 70 may correct the rotational speed of the fan 20 and perform the ignition operation of the spark plug 85 in the same manner as in step S26.

[0081] In any case, when the control device 70 determines that the wind speed Y is greater than the second wind speed Y2 [m / s] in step S18 (when the answer is No in step S18), the process proceeds to step S19. In step S19, the control device 70 determines whether the wind speed Y of the wind blowing at the exhaust port 90 at the time of step S19 is equal to or less than the second wind speed Y2 [m / s]. The value of the second wind speed Y2 is stored in the memory, for example. In the present embodiment, the second wind speed Y2 is set to 30 [m / s], but other values may also be used. The case where the wind speed Y of the wind blowing at the exhaust port 90 is equal to or less than the second wind speed Y2 means the case where the wind pressure applied from the outside into the exhaust port 90 is equal to or less than the second value.

[0082] The control device 70 identifies the wind speed Y at the time of step S19 in the same way as in step S13, for example. When it is determined in step S19 that the wind speed Y is greater than the second wind speed Y2 [m / s] (in the case of No in step S19), the process proceeds to step S25. When the control device 70 proceeds with the process to step S25, it determines whether or not a third fixed time (for example, 2 minutes) has elapsed since it was determined Yes in step S17 in step S25. When the control device 70 determines in step S25 that the third fixed time has not elapsed (in the case of No in step S25), the process returns to step S19, and again, in step S19, it determines whether or not the wind speed Y of the wind blowing out of the exhaust port 90 at the time of step S19 is less than or equal to the second wind speed Y2 [m / s]. When the control device 70 determines in step S25 that the third fixed time (for example, 2 minutes) has elapsed since it was determined Yes in step S17, it outputs an error and aborts the ignition process. Thus, when the wind speed does not become less than or equal to the second wind speed Y2 even after the third fixed time (for example, 2 minutes) has elapsed (in the case of Yes in step S25), since the influence of the wind speed generated during ignition is large, an error is output and the ignition process is aborted. The output of the error in this case may be an audio output (buzzer sound or voice output of a message) indicating abnormality, may be an output for displaying an error code or error message on a display device, or may be a data output for transmitting information to an external device. The above-mentioned third fixed time is stored in the memory, for example. In the above example, the third fixed time is 2 minutes, but it may be a value other than this.

[0083] When the control device 70 determines in step S19 that the wind speed Y at the exhaust port 90 at the time of step S19 is less than or equal to the second wind speed Y2 [m / s] (Yes in step S19), the process proceeds to step S20, and it is determined whether the wind speed Y of the wind blowing at the exhaust port 90 has continued to be less than or equal to the second wind speed Y2 for a certain period (for example, 5 seconds). The certain period (for example, 5 seconds) in step S20 is a standby time and an example of the second specified period. When the control device 70 determines in step S20 that the wind speed Y of the wind blowing at the exhaust port 90 has not continued to be less than or equal to the second wind speed Y2 for a certain period (No in step S20), the process returns to step S19, and the determination in step S19 is performed again. The certain period (for example, 5 seconds) in step S20 is preferably set to a value that can be estimated that the influence of the wind has disappeared, and the certain period is stored in the memory, for example. The certain period is not limited to 5 seconds, and may be other than this value. For example, step S19 may not be provided, and ignition may be performed without continuing for a certain period.

[0084] When the control device 70 determines in step S20 that the wind speed Y of the wind blowing at the exhaust port 90 is equal to or lower than the second wind speed Y2 and continues for a certain period of time (Yes in step S20), the process proceeds to step S21. The control device corrects the slow ignition rotation speed of the fan 20 to a rotation speed higher than a predetermined rotation speed using a correction coefficient, and causes the ignition plug 85 to perform an ignition operation to ignite the burner. When the condition for operating the hot water supply circuit 2 is satisfied in step S11 (when the condition for igniting the burner 8A is satisfied), the control device 70 ignites the ignition plug 85 on the burner 8A side in step S21 to burn the burner 8A. When the condition for operating the heating circuit 3 is satisfied in step S11 (when the condition for igniting the burner 33A is satisfied), the control device 70 ignites the ignition plug 85 on the burner 33A side in step S21 to burn the burner 33A. It is desirable to ignite the ignition plug 85 while correcting the slow ignition rotation speed of the fan 20 with a correction coefficient, assuming that the ignition at this time may be affected by some wind. When the state of being equal to or lower than the second wind speed Y2 [m / s] continues for the above-mentioned certain period of time (Yes in step S20), since the wind speed has decreased at least for about the above-mentioned certain period of time, by utilizing this state and proceeding to step S21 to ignite the burners 8A and 33A with the ignition plug 85, it is possible to avoid the disadvantage that the user cannot use hot water supply or heating.

[0085] FIG. 3 shows an example of the operation of the water heater 1. In the example of FIG. 3, the operation start condition in the hot water supply circuit 2 (the water volume detected by the water volume sensor 14 exceeding the threshold value) is satisfied at time t1, and time t1 is the timing when it is determined as Yes in step S11. Then, the timing when step S12 is started is time t2, and the period from time t2 to time t3 is the period of the process of step S12. In the example of FIG. 3, the rotation speed of the fan 20 is stabilized at the first rotation speed X1 at time t3. The example of FIG. 3 is an example where the wind speed Y does not become less than the first wind speed Y1 between time t3 and t4. Therefore, the process of step S15 is started at time t4, and the rotation speed of the fan 20 is controlled to the second rotation speed X2 between time t4 and time t5. Time t5 is the point in time when it is determined as Yes in step S16 (the point in time when a first fixed time (for example, 3 seconds) has elapsed since the start of rotation at the second rotation speed X2). The point in time of time t6 is the point in time when it is determined as Yes in step S17. The example of FIG. 3 is an example where the fluctuation range of the rotation speed of the fan 20 is stabilized at ±α% or less between time t5 and time t6, and the processes after step S19 are performed after time t6.

[0086] FIG. 4 shows an example of the operation of the hot water heater 1. In FIG. 4, the period during which the threshold value as the correction coefficient for determining the wind speed is used is indicated by a solid line, and the threshold value during the period when the threshold value as the correction coefficient for determining the wind speed is not used is indicated by a broken line. In the example of FIG. 4, the rotation speed of the fan 20 is stable at the first rotation speed X1 at time t3. As shown by reference numeral A1 in FIG. 4, when the wind speed Y is determined to be less than the first wind speed Y1 between time t3 and t4, the fan 20 ignites the ignition plug 85 on the burner 33A side as the normal rotation speed (predetermined rotation speed) to burn the burner 33A. As shown by reference numeral B1, when the wind speed Y is equal to or greater than the first wind speed Y1 and less than the reference wind speed YB between time t3 and t4, the rotation speed of the fan 20 is corrected to a rotation speed higher than the normal rotation speed (predetermined rotation speed), and the ignition plug 85 on the burner 33A side is ignited to burn the burner 33A. As shown by reference numeral C1, when the wind speed Y is equal to or greater than the reference wind speed YB between time t3 and t4, the process proceeds to the second preliminary operation. In the second preliminary operation, the rotation speed of the fan 20 is controlled to the second rotation speed X2 higher than the first rotation speed X1. As shown by reference numeral C21, when the wind speed Y is determined to be less than or equal to the second wind speed Y2 between time t5 and t6, the rotation speed of the fan 20 is corrected to a rotation speed higher than the normal rotation speed (predetermined rotation speed), and the ignition plug 85 on the burner 33A side is ignited to burn the burner 33A. As shown by reference numeral C22, when the wind speed Y is determined to be greater than the second wind speed Y2 between time t5 and t6, there may be a strong wind (exceeding 30 [m / s]) blowing near the exhaust port 90, so the process proceeds to the air supply standby state. In the air supply standby state, as shown by reference numeral C31, when the wind speed Y is determined to be less than or equal to the second wind speed Y2 after time t6, since the wind speed becomes weak and the correction coefficient becomes high, the rotation speed of the fan 20 is corrected to a rotation speed higher than the normal rotation speed (predetermined rotation speed), and the ignition plug 85 on the burner 33A side is ignited to burn the burner 33A. As shown by reference numeral C32, when the wind speed Y is determined to be greater than the second wind speed Y2 after time t6, the air supply standby is continued. Then, as shown by reference numeral C4, when 2 minutes have elapsed in the sending standby state, an error is output and the ignition process is aborted.

[0087] 6. Example of effects In a water heater 1 which is an example of a combustion device, when the fan is rotated at a relatively low first rotation speed X1 (during the first preliminary operation) and the wind speed of the wind blowing out of the exhaust port 90 is less than the first wind speed Y1, there is a high possibility that the obstruction near the exhaust port 90 is low. In this case, ignition can be performed earlier. When the wind speed of the wind blowing out of the exhaust port 90 during the second preliminary operation is equal to or higher than the reference wind speed YB, there is a possibility that the obstruction near the exhaust port 90 is high. In this case, the wind speed can be accurately measured by rotating the fan at a relatively high second rotation speed X2. Further, even when the wind speed of the wind blowing out of the exhaust port 90 during the first preliminary operation is equal to or higher than the first wind speed Y1, less than the reference wind speed YB, or when the wind speed of the wind blowing out of the exhaust port 90 during the second preliminary operation is equal to or less than a second wind speed Y2 which is greater than the reference wind speed YB, the ignition operation can be performed and the burner can be burned with the fan rotated at an ignition rotation speed higher than a predetermined ignition rotation speed. That is, even if the water heater 1 cannot immediately clear the ignition conditions during the first preliminary operation, it can carefully re-determine the obstruction based on the second preliminary operation and burn the burner when the conditions are cleared. Therefore, the water heater 1 can easily perform ignition control appropriately corresponding to the wind speed of the wind blowing out of the exhaust port 90

[0088] When the fluctuation range of the wind speed within the first specified period during which the fan 20 is rotated at the second rotation speed X2 during the second preliminary operation of the water heater 1 is within a predetermined value, that is, when there is a high possibility that the rotation speed of the fan 20 is stable, and the wind speed at the exhaust port 90 is equal to or less than the second wind speed, the ignition operation can be performed with the fan rotated at an ignition rotation speed higher than a predetermined ignition rotation speed, so that ignition can be more reliably achieved.

[0089] When a strong wind blows at the exhaust port 90 during the second preliminary operation of the water heater 1, the water heater 1 can prevent poor ignition and explosive ignition by waiting without performing the ignition operation, and can continue the second preliminary operation without interruption during the waiting period, so that the ignition operation can be performed more quickly when the wind speed becomes equal to or less than the second wind speed Y2.

[0090] The current sensor 75 functions as an example of a current detection unit and detects the drive current supplied to the fan 20. And the rotation speed sensor 76 detects the rotation speed of the fan 20. The control device 70 determines the external wind speed based on the current detected by the current sensor 75 and the rotation speed detected by the rotation speed sensor 76. In this way, the water heater 1 can perform control based on the wind speed by using the configuration of driving the fan 20 without using a complicated wind speed sensor.

[0091] <Other Embodiments> The present invention is not limited to the embodiments described by the above description and drawings. For example, the features of the above-described or below-described embodiments can be combined in any combination within a non-contradictory range. Also, any feature of the above-described or below-described embodiments can be omitted if it is not explicitly specified as essential. Furthermore, the above-described embodiments may be modified as follows.

[0092] In the example of FIG. 2, when it is determined as Yes in steps S13 and S14, the fan 20 is rotated at the second rotation speed X2 in step S15. However, when it is determined as Yes in step S13, it is determined whether the wind speed Y at the time of step S13 is less than a third wind speed Y3 that is greater than the first wind speed Y1 and less than the second wind speed Y2. When the wind speed Y at the time of S13 is equal to or greater than the first wind speed Y1 and less than the third wind speed Y3, the ignition plug 85 is ignited while correcting the slow ignition rotation speed of the fan 20 with a correction coefficient. When the wind speed Y at the time of S13 is equal to or greater than the third wind speed Y3, the processing after step S15 may be performed.

[0093] In the water heater 1 of the above embodiment, the wind speed is detected based on the drive current detected by the current sensor 75 and the rotation speed of the fan 20 detected by the rotation speed sensor 76. However, the present invention is not limited to this, and other sensors or the like may be used to detect the wind speed. For example, the water heater 1 may directly detect the wind speed of the wind blowing out of the exhaust port 90 by using a wind speed sensor such as a rotary type or an ultrasonic type, and use the detected wind speed to make the determination in steps S13 and S19.

[0094] In the above embodiment, the water heater 1 is taken as an example of a combustion device, but the combustion device may be configured as a water heater without a heating circuit.

[0095] It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed this time, and it is intended that all modifications within the scope shown by the claims or within the scope equivalent to the claims are included.

Explanation of Reference Numerals

[0096] 1: Water heater (combustion device) 1A: Container 2: Hot water supply circuit 3: Heating circuit 4: Bath circuit 5A: Hot water supply combustion chamber 6A: Heating combustion chamber 7: Hot water supply side heat exchanger 7Z: Fin 8: Hot water supply side burner unit 8A: Hot water supply burner (burner) 9A: Burner block 9B: Burner block 9C: Burner block 10: Hot water outlet pipe 11: Water supply pipe 20: Fan 20A: Drive source 20B: Rotating body 32: Heating side heat exchanger 32A: First heating side heat exchanger 32B: Second heating side heat exchanger 33: Heating side burner unit 33A: Heating burner (burner) 34A: Burner block 34B: Burner block 35A: Inflow part 35B: First outflow part 35C: Second outflow part 36: Expansion tank 36C: Inlet part 36B: Outlet part 37: Heating circulation pump 38A: First internal flow path 38B: Second internal flow path 38C: Common return flow path 38K: Common forward flow path 38J: Branch portion 39A: First heat dissipation terminal 39Z: Second heat dissipation terminal 38G: First terminal flow path 38H: Second terminal flow path 39H: First valve 39G: Second valve 46: Bypass flow path 48: Heat medium circulation path 50: Bathtub heat exchanger 56: Supplementary heating branch portion 70: Control device (control unit) 85: Ignition plug (ignition means)

Claims

1. a burner for burning gas, a container for housing the burner, a fan for supplying air into the container, ignition means for igniting the gas supplied to the burner, A combustion device comprising: a control unit for controlling the ignition operation of the ignition means and the rotation of the fan, an exhaust port which is a path for discharging the combustion exhaust gas generated by the combustion of the gas from the container to the outside of the combustion device, The control unit: Before igniting the gas by the ignition means, a first preliminary operation is performed to rotate the fan at a first rotational speed, On the condition that the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than a predetermined reference wind speed, a second preliminary operation is performed to rotate the fan at a second rotational speed higher than the first rotational speed, When the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is less than a first wind speed lower than the reference wind speed, with the fan rotating at a predetermined rotational speed for ignition, the ignition means is made to perform an ignition operation to burn the burner, When the wind speed of the wind blowing out of the exhaust port during the first preliminary operation is equal to or higher than the first wind speed and less than the reference wind speed, or when the wind speed of the wind blowing out of the exhaust port during the second preliminary operation is equal to or lower than a second wind speed higher than the reference wind speed, with the fan rotating at a rotational speed for ignition higher than the predetermined rotational speed for ignition, the ignition means is made to perform an ignition operation to burn the burner Combustion device.

2. When the control unit determines that the fluctuation range of the wind speed within a first specified period during which the fan is rotated at the second rotational speed during the second preliminary operation is within a predetermined value, and when the wind speed of the wind blowing out of the exhaust port is equal to or lower than the second wind speed, the control unit makes the ignition means perform an ignition operation to burn the burner with the fan rotating at a rotational speed for ignition higher than the predetermined rotational speed for ignition The combustion device according to Claim 1.

3. When the wind speed of the wind blowing out of the exhaust port is greater than the second wind speed during the second specified period in which the control unit rotates the fan at the second rotational speed during the second preliminary operation, the control unit waits without performing the ignition operation of the ignition means until the wind speed becomes equal to or less than the second wind speed while maintaining the fan at the second rotational speed. When the wind speed of the wind blowing out of the exhaust port becomes equal to or less than the second wind speed during the waiting period, the control unit causes the ignition means to perform an ignition operation to burn the burner while rotating the fan at an ignition rotational speed higher than the predetermined ignition rotational speed. The combustion device according to claim 2.

4. The first specified period is shorter than the second specified period. The combustion device according to claim 3.

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