Combined heat source machine

Abstract

To suppress generation of resonance in switching from a state where only a heating operation is executed to a state where a simultaneous operation is executed and prevent uncomfortable feeling of a user, in a combined heat source machine that includes a first heat exchanger 21 for hot water supply, a first burner 31 serving as a heating source of the first heat exchanger, a second heat exchanger 22 for heating and a second burner 32 serving as a heating source of the second heat exchanger and that can execute a hot water supply operation, the heating operation and the simultaneous operation for simultaneously executing the hot water supply operation and the heating operation.SOLUTION: In switching from a state where only a heating operation is executed to a state where a simultaneous operation is executed, a priority operation control for prioritizing either one operation of the heating operation or a hot water supply operation and limiting the other operation is executed for a predetermined period. The operation to be prioritized in the priority operation control is determined on the basis of a type of a heating terminal that is being operated in the heating operation. For example, if the heating terminal in operation is a mist device 72, the heating operation is prioritized.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a combined heat source machine including a first heat exchanger for heating water supplied to a hot water supply terminal, a first burner serving as a heat source of the first heat exchanger, a first combustion chamber in which the first heat exchanger and the first burner are disposed, a second heat exchanger for heating a heat medium circulated in a heating circuit, a second burner serving as a heat source of the second heat exchanger, a second combustion chamber in which the second heat exchanger and the second burner are disposed, a combustion fan for supplying combustion air to the first combustion chamber and the second combustion chamber, and a control means.

Background Art

[0002] In this type of combined heat source machine, a hot water supply operation of burning the first burner and supplying the water heated by the first heat exchanger to the hot water supply terminal, a heating operation of burning the second burner and heating the heat medium while circulating the heat medium in the heating circuit by the second heat exchanger, and a simultaneous operation of simultaneously executing the hot water supply operation and the heating operation are executable.

[0003] By the way, when switching from a state of executing only the heating operation to a state of executing the simultaneous operation, resonance sound is likely to occur until the combustion of the first burner becomes stable. Therefore, conventionally, according to Patent Document 1, when switching from a state of executing only the heating operation to a state of executing the simultaneous operation, the heating operation is restricted so that the combustion amount of the second burner, which is the burner corresponding to the heating operation, becomes equal to or less than the required combustion amount for a predetermined period to suppress the generation of resonance sound.

[0004] However, when the heating operation is restricted in this way, it may give a sense of discomfort to the user depending on the type of heating terminal operating in the heating operation.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In view of the above points, an object of the present invention is to provide a combined heat source machine that can suppress the generation of resonance noise when switching from a state where only heating operation is performed to a state where simultaneous operation is performed, and can make it difficult to give a sense of discomfort to the user.

Means for Solving the Problems

[0007] To solve the above problems, the present invention provides a combined heat source machine including a first heat exchanger for heating water supplied to a hot water supply terminal, a first burner serving as a heating source of the first heat exchanger, a first combustion chamber in which the first heat exchanger and the first burner are disposed, a second heat exchanger for heating a heat medium circulated in a heating circuit, a second burner serving as a heating source of the second heat exchanger, a second combustion chamber in which the second heat exchanger and the second burner are disposed, a combustion fan for supplying combustion air to the first combustion chamber and the second combustion chamber, and a control means. The combined heat source machine is capable of performing a hot water supply operation in which the first burner is burned and the water heated by the first heat exchanger is supplied to the hot water supply terminal, a heating operation in which the second burner is burned and the heat medium is circulated in the heating circuit while being heated by the second heat exchanger, and a simultaneous operation in which the hot water supply operation and the heating operation are performed simultaneously. The control means is configured to execute priority operation control for restricting the other operation so that the combustion amount of the burner corresponding to the other operation becomes equal to or less than the required combustion amount while giving priority to either the heating operation or the hot water supply operation for a predetermined period when switching from a state where only the heating operation is performed to a state where the simultaneous operation is performed. The operation to be prioritized in the priority operation control is determined based on the type of the heating terminal operating in the heating operation.

[0008] According to the present invention, for the operation to be prioritized in the priority operation control, for example, when the operating heating terminal requires a large combustion amount of the second burner, the operation is a heating operation; when it is a terminal that does not require a large combustion amount of the second burner, the operation can be a hot water supply operation. Thereby, it is possible to suppress the generation of resonance sound during the switching from the state of executing only the heating operation to the state of executing the simultaneous operation by the priority operation control, and it is possible to make it difficult to give a sense of discomfort to the user, improving the comfort.

[0009] Further, in the present invention, when the heating terminal operating during the heating operation is a mist device that sprays water heated by heat exchange with the heat medium circulating in the heating circuit into the bathroom, it is desirable that the operation to be prioritized in the priority operation control is the heating operation. Here, during the operation of the mist device, since the sprayed water touches the user in the bathroom, the user can easily recognize the temperature change of the sprayed water. Therefore, when the hot water supply operation is prioritized by the priority operation control during the operation of the mist device, the combustion amount of the second burner becomes less than or equal to the required combustion amount necessary to maintain the temperature of the sprayed water at an appropriate temperature, and the temperature of the sprayed water becomes lower than the appropriate temperature, giving a sense of discomfort to the user. On the other hand, if the heating operation is prioritized as described above by the priority operation control during the operation of the mist device, the temperature of the sprayed water is maintained at an appropriate temperature, and it is possible to make it difficult to give a sense of discomfort to the user.

[0010] Incidentally, the resonance sound is more likely to occur as the first combustion chamber is colder, and less likely to occur as the first combustion chamber warms up. Therefore, in the present invention, it is desirable that the predetermined period for executing the priority operation control is set shorter as the combustion amount of the first burner is larger according to the combustion amount. According to this, in a state where the combustion amount of the first burner is large and the first combustion chamber warms up faster, the above-mentioned predetermined period is set shorter. Therefore, it is possible to avoid the unnecessary continuation of the priority operation control even after the first combustion chamber warms up and the resonance sound becomes less likely to occur, improving the convenience.

[0011] In addition, when combustion chamber temperature detection means for detecting the temperature of the first combustion chamber is provided, when the detected temperature of the combustion chamber temperature detection means reaches a predetermined temperature or higher, the priority operation control may be terminated. According to this, similar to the above, after the first combustion chamber warms up and the resonance sound is less likely to occur, it is possible to avoid the wasteful continuation of the priority operation control, and the convenience is improved.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0013] The combined heat source machine according to the embodiment of the present invention shown in FIG. 1 includes a first heat exchanger 2 for hot water supply provided in a single can body 1 1 and a second heat exchanger 2 for heating 2 and a first heat exchanger 2 1 for heating the first heat exchanger 2 1 a first burner 3 below 1 and a second heat exchanger 2 2 for heating the second heat exchanger 2 2 a second burner 3 below 2 and is provided with. In the can body 1, a partition plate 12 is provided to partition the space in the can body 1 into a first combustion chamber 11 1 in which the first heat exchanger 2 1 and the first burner 3 are arranged inside 1 and a second combustion chamber 11 2 in which the second heat exchanger 2 2 and the second burner 3 are arranged inside 2 and is provided with. Further, the combined heat source machine includes a combustion fan 4 for supplying combustion air to the first combustion chamber 11 1 and the second combustion chamber 11 2 and a controller 5 composed of a microcomputer as control means. In addition, in the present embodiment, the first combustion chamber 11 1 and the second combustion chamber 11 2Although combustion air is supplied from the common combustion fan 4, it is also possible to supply combustion air from separate combustion fans to the first combustion chamber 11 1 and the second combustion chamber 11 2 respectively. Also, on the front surface of the upper part of the first and second heat exchangers 2 1 , 2 2 of the can body 1, exhaust ports 13 are provided for discharging combustion gas generated by combustion in the first and second burners 3 1 , 3 2 .

[0014] In the first heat exchanger 2 1 , an upstream water supply pipe 6a and a downstream hot water supply pipe 6b are connected. Also, a bypass pipe 6c that branches from the water supply pipe 6a and joins the hot water supply pipe 6b is provided. A water temperature sensor 61, a water volume sensor 62, and a water volume control valve 63 controlled by a controller 5 are interposed in the water supply pipe 6a, and a bypass water volume control valve 64 controlled by the controller 5 is interposed in the bypass pipe 6c. Also, a hot water temperature sensor 65 near the upstream end and a hot water temperature sensor 66 downstream of the confluence point of the bypass pipe 6c are provided in the hot water supply pipe 6b.

[0015] Detection signals from the water temperature sensor 61, the water volume sensor 62, and the hot water temperature sensors 65 and 66 are input to the controller 5. Then, when the opening of the hot water supply terminal 67 at the downstream end of the hot water supply pipe 6b starts water flow to the first heat exchanger 2 1 and the detected water volume of the water volume sensor 62 becomes equal to or greater than a predetermined lower limit water volume, the combustion fan 4 is driven and the first burner 3 1 is combusted to start a hot water supply operation for supplying the water heated in the first heat exchanger 2 1 to the hot water supply terminal 67. During the hot water supply operation, the controller 5 calculates the required combustion amount of the first burner 3 1 required to supply hot water at a predetermined set temperature set by a remote control (not shown) from the detected water temperature of the water temperature sensor 61 and the detected water volume of the water volume sensor 62 as the required combustion amount, and performs feedforward control to control the combustion amount of the first burner 3 1 to become the required combustion amount. Further, the first burner 3 1The combustion amount is feedback-controlled. Also, when the amount of water is too large and the detected hot water temperature of the hot water temperature sensor 66 does not rise to the set temperature even when the combustion amount of the first burner 3 1 is maximized, the amount of water is throttled by the water volume control valve 63 until the detected hot water temperature of the hot water temperature sensor 66 rises to the set temperature.

[0016] The second heat exchanger 2 2 is installed in a heating circuit 7 that circulates a heat medium (such as water or antifreeze) between various heating terminals described later. In the present embodiment, as heating terminals, a bathroom heating device 71 installed in the ceiling portion BRa of the bathroom BR, a mist device 72 attached to the bathroom heating device 71, and a floor heating panel 73 are provided. The bathroom heating device 71 has a ventilation path 713 inside that connects a suction port 711 opened on the lower surface facing the bathroom BR and a blowout port 712 with a variable louver 712a. In the ventilation path 713, a circulation fan 714 that sucks air in the bathroom BR from the suction port 711 and blows it into the bathroom BR from the blowout port 712, and a radiator 715 that heats the air flowing through the ventilation path 713 are arranged. Further, the mist device 72 includes a mist nozzle 721 arranged on the lower surface of the bathroom heating device 71 and a mist water supply pipe 722 that supplies water to the mist nozzle 721. In the mist water supply pipe 722, a mist water supply valve 723 controlled by the controller 716 of the bathroom heating device 71, a liquid-to-liquid heat exchanger 724, and a mist temperature sensor 725 are provided in order from the upstream side. Incidentally, the controller 716 of the bathroom heating device 71 is communicably connected to the controller 5 of the composite heat source machine.

[0017] The heating circuit 7 includes a forward path 7a that sends the heat medium heated by the second heat exchanger 2 2 to the radiator 715 of the bathroom heating device 71, and a return path 7b that returns the heat medium that has passed through the radiator 715 to the second heat exchanger 2 2 is provided. In the forward path 7a, the second heat exchanger 2 2There is provided a heat medium temperature sensor 74 for detecting the temperature of the heat medium sent out from [heat medium source], and a bathroom heating medium valve 75 near the radiator 715 controlled by the controller 716 of the bathroom heating device 71. In the return path 7b, a cistern 76 and a circulation pump 77 controlled by the controller 5 are interposed. The heating circuit 7 further includes a mist supply path 7c branched from a portion of the supply path 7a upstream of the bathroom heating medium valve 75 that supplies the heat medium to the primary side of the liquid-to-liquid heat exchanger 724, a mist return path 7d that returns the heat medium that has passed through the primary side of the liquid-to-liquid heat exchanger 724 to the vicinity of the upstream end of the return path 7b, a floor heating supply path 7e branched from a portion of the return path 7b downstream of the circulation pump 77 that supplies the heat medium to the floor heating panel 73, a floor heating return path 7f that returns the heat medium that has passed through the floor heating panel 73 to a portion of the return path 7b upstream of the cistern 76, and a bypass path 7g that branches from the supply path 7a and merges into the cistern 76. Further, a mist heating medium valve 78 controlled by the controller 716 of the bathroom heating device 71 is interposed in the mist return path 7d, and a floor heating heating medium valve 79 controlled by the controller 5 of the composite heat source machine is interposed in the floor heating supply path 7e.

[0018] When the operation switch (not shown) of the bathroom heating device 71 is turned on, the circulation fan 714 is driven, the bathroom heating medium valve 75 is opened, and further, the circulation pump 77 is driven and the second burner 3 2 is combusted. Thereby, while circulating the heat medium between the second heat exchanger 2 2 and the radiator 715 through the heating circuit 7, the second heat exchanger 2 2 heats it, and a bathroom heating operation for heating the air in the bathroom by the radiator 715 is performed. At this time, the combustion amount of the second burner 3 2 is feedback-controlled so that the detected temperature of the heat medium temperature sensor 74 becomes a predetermined high temperature setting temperature (for example, 80 °C).

[0019] When the operation switch (not shown) of the mist device 72 is turned on, the mist water supply valve 723 and the mist heating medium valve 78 are opened, and the circulation pump 77 is driven and the second burner 3 2 is combusted. Thereby, the heat medium is passed through the second heat exchanger 2 2while circulating between the second heat exchanger 2 and the liquid-liquid heat exchanger 724 via the heating circuit 7 2 is heated, and hot water heated by heat exchange with the heat medium in the liquid-liquid heat exchanger 724 is sprayed into the bathroom BR from the mist nozzle 721, i.e., a heating operation, namely a mist operation, is performed. At this time, the combustion amount of the second burner 3 is feedback-controlled so that the detected temperature of the heat medium temperature sensor 74 becomes the high temperature set temperature, and the flow rate of the heat medium flowing through the liquid-liquid heat exchanger 724 is controlled by the heat medium valve 78 for mist so that the detected temperature of the mist temperature sensor 725 becomes a predetermined mist set temperature. Incidentally, in the mist operation, the bathroom heating operation may be executed simultaneously. 2 When the operation switch (not shown) for the floor heating is turned on, the heat medium valve 79 for the floor heating is opened, and the circulation pump 77 is driven and the second burner 3

[0020] burns. In this case, the heat medium is circulated via the bypass path 7g and the cistern 76 while being heated by the second heat exchanger 2 2 and a part of the heat medium is circulated between the cistern 76 and the floor heating panel 73. As a result, the heat from the second heat exchanger 2 2 is transmitted to the floor heating panel 73 via the cistern 76, and the floor heating operation is performed. At this time, the combustion amount of the second burner 3 is feedback-controlled so that the detected temperature of the heat medium temperature sensor 74 becomes a predetermined low temperature set temperature (for example, 60°C). 2 2 2 The first burner 3

[0021] has three burner blocks 3 1 a, 3 1 a, 3 1 b, 3 1 c. Specifically, a total of 15 unit burners 3a are arranged in parallel, and the first burner block 3 1 a is composed of 3 unit burners 3a, the second burner block 3 1 b is composed of 5 unit burners 3a, and the third burner block 3 1 c is composed of the remaining 7 unit burners 3a. Further, the second burner 3 2 has two burner blocks 3 2 a, 32 It has b. Specifically, six unit burners 3a are arranged side by side, and two unit burners 3a form the fourth burner block 3 2 a, and the remaining four unit burners 3a form the fifth burner block 3 2 b. Each burner block 3 1 a to 3 2 b can also be formed by each one burner having the same combustion capacity as a predetermined number of unit burners 3a instead of being composed of a predetermined number of unit burners 3a 1 a to 3 2 b.

[0022] The first burner 3 1 and the second burner 3 2 are provided with a main valve 81 and a proportional valve 82 on its downstream side in the common gas supply path 8 for them. Also, the gas supply path 8 branches into a branch gas supply path 8 1 for the first burner 3 1 and a branch gas supply path 8 2 for the second burner 3 2 downstream of the proportional valve 82. The branch gas supply path 8 1 for the first burner 3 1 is provided with the first to third three capacity switching valves 83 1 a, 3 1 b, 3 1 c to change the combination of burner blocks 3 1 supplying fuel gas to switch the combustion capacity of the first burner 3 1 , 83 2 , 83 3 in multiple stages, and the branch gas supply path 8 2 for the second burner 3 2 is provided with the fourth and fifth two capacity switching valves 83 2 a, 3 2 b to change the combination of burner blocks 3 1 supplying fuel gas to switch the combustion capacity of the second burner 3 4 , 83 5 in multiple stages. The main valve 81, the proportional valve 82, and the first to fifth capacity switching valves 83 1 ~83 5 are controlled by the controller 5.

[0023] First burner 3 1 Specifically explaining the switching of the combustion capacity of 1 , when the first capacity switching valve 83 1 is opened to supply fuel gas only to the first burner block 3 1 a, the combustion capacity of the first burner 3 1 is switched to the minimum first-stage capacity (the capacity of one-third of the unit burner 3), and when the second capacity switching valve 83 2 is opened to supply fuel gas only to the second burner block 3 1 b, the combustion capacity of the first burner 3 1 is switched to the second-stage capacity (the capacity of one-fifth of the unit burner 5), and when both the first and second capacity switching valves 83 1 , 83 2 are opened to supply fuel gas to both the first and second burner blocks 3 1 a, 3 1 b, the combustion capacity of the first burner 3 1 is switched to the third-stage capacity (the capacity of one-eighth of the unit burner 8), and when both the first and third capacity switching valves 83 1 , 83 3 are opened to supply fuel gas to both the first and third burner blocks 3 1 a, 3 1 c, the combustion capacity of the first burner 3 1 is switched to the fourth-stage capacity (the capacity of one-tenth of the unit burner 10), and when the first to third capacity switching valves 83 1 , 83 2 , 83 3 are opened to supply fuel gas to the first to third burner blocks 3 1 a, 3 1 b, 3 1 c, the combustion capacity of the first burner 3 1 is switched to the maximum fifth-stage capacity (the capacity of one-fifteenth of the unit burner 15). And when the required combustion amount exceeds the maximum combustion amount obtained with the current combustion capacity, the combustion capacity is increased by one step, and when the required combustion amount is less than the minimum combustion amount obtained with the current combustion capacity, the combustion capacity is decreased by one step.

[0024] Also, the second burner 3 2Specifically explaining the switching of the combustion capacity, the fourth capacity switching valve 83 4 is opened to supply fuel gas only to the fourth burner block 3 2 a, thereby switching the combustion capacity of the second burner 3 2 to the minimum first-stage capacity (the capacity of two unit burners), and the fifth capacity switching valve 83 5 is opened to supply fuel gas only to the fifth burner block 3 2 b, thereby switching the combustion capacity of the second burner 3 2 to the second-stage capacity (the capacity of four unit burners), and both the fourth and fifth capacity switching valves 83 4 ,83 5 are opened to supply fuel gas to both the fourth and fifth burner blocks 3 2 a,3 2 b, thereby switching the combustion capacity of the second burner 3 2 to the third-stage capacity (the capacity of six unit burners). And when the required combustion amount (the combustion amount required to heat the heat medium to the set temperature (high-temperature set temperature during bathroom heating operation and mist operation, low-temperature set temperature during floor heating operation)) exceeds the maximum combustion amount that can be obtained with the current combustion capacity, the combustion capacity is increased by one step, and when the required combustion amount is less than the minimum combustion amount that can be obtained with the current combustion capacity, the combustion capacity is decreased by one step.

[0025] The combined heat source machine of this embodiment can execute a hot water supply operation, a heating operation, and a simultaneous operation that simultaneously executes the hot water supply operation and the heating operation. Here, when switching from the state of executing only the heating operation to the state of executing the simultaneous operation, the first burner 3 1During the period until the combustion stabilizes, resonance sounds are likely to occur. Therefore, in order to suppress the generation of resonance sounds, when switching from the state of executing only the heating operation to the state of executing the simultaneous operation, the controller 5 gives priority to either the heating operation or the hot water supply operation for a predetermined period so that the combustion amount of the burner corresponding to the other operation is equal to or less than the required combustion amount, and executes priority operation control to limit the other operation. The operation to be prioritized in the priority operation control is determined based on the type of the heating terminal operating in the heating operation. Hereinafter, the priority operation control will be specifically described with reference to FIG. 2.

[0026] The priority operation control is executed during the heating operation. First, in STEP1, it is determined whether the detected water volume of the water volume sensor 62 is equal to or greater than a predetermined lower limit water volume, that is, whether an instruction to start the hot water supply operation has been issued. When an instruction to start the hot water supply operation has been issued, the process proceeds to STEP2, and it is determined whether the heating terminal operating in the heating operation is the mist device 72, that is, whether the mist operation is being executed. If the mist operation is being executed, the process proceeds to STEP3, and priority operation control is executed to prioritize the heating operation and limit the hot water supply operation. Next, in STEP5, it is determined whether a predetermined restriction time has elapsed since the start of the priority operation control.

[0027] Here, during the execution of the mist operation, since the sprayed water touches the user in the bathroom, the user can easily recognize the temperature change of the sprayed water. Therefore, when the hot water supply operation is prioritized in the priority operation control during the execution of the mist operation, the combustion amount of the second burner 3 2 becomes equal to or less than the required combustion amount necessary to maintain the temperature of the sprayed water at an appropriate temperature, and the temperature of the sprayed water becomes lower than the appropriate temperature, giving the user a sense of discomfort. On the other hand, if the heating operation is prioritized as described above in the priority operation control during the execution of the mist operation, the temperature of the sprayed water can be maintained at an appropriate temperature, making it difficult to give the user a sense of discomfort.

[0028] In addition, when restricting the hot water supply operation in STEP3, the detected hot water temperature of the hot water temperature sensor 66 is the first burner 3 1Reduce the water volume with the water volume control valve 63 so that the set temperature is not exceeded due to the decrease in the combustion amount. Also, if the mist operation is not being executed, proceed to STEP4 and execute priority operation control that restricts the heating operation in favor of the hot water supply operation. Next, in STEP6, determine whether a predetermined limit time has elapsed since the start of the priority operation control. And when it is determined in STEP5 or STEP6 that the limit time has elapsed, proceed to STEP7, release the priority operation control, and shift to normal simultaneous operation.

[0029] Here, when the exhaust port 13 at the upper part of the can body 1 is open forward and the exhaust resistance of the combustion gas is small, and when the exhaust port 13 is covered with an exhaust hood (not shown) that guides the combustion gas laterally for discharge and the exhaust resistance of the combustion gas is large, the resonance sound is more likely to occur as the exhaust resistance is larger. Also, when the type of fuel gas (gas type) is 13A, the resonance sound is more likely to occur than when the gas type is LP. Therefore, the restriction of the hot water supply operation in STEP3 is carried out by restricting the combustion capacity of the first burner 3 1 to below the capacity of the fourth stage when the gas type is 13A and the exhaust resistance is small, and by restricting the combustion capacity of the first burner 3 1 to below the capacity of the third stage when the gas type is 13A and the exhaust resistance is large. When the gas type is LP, regardless of the size of the exhaust resistance, the combustion capacity of the first burner 3 1 is restricted to below the capacity of the fourth stage. Also, the restriction of the heating operation in STEP5 is carried out by restricting the combustion capacity of the second burner 3 2 to below the capacity of the second stage regardless of the gas type and the size of the exhaust resistance. Incidentally, restricting the combustion capacity of the first burner 3 1 to below the capacity of the fourth stage or the third stage means that even if the required combustion amount exceeds the maximum combustion capacity of the fourth stage or the third stage, the combustion amount of the first burner 3 1 is restricted to below the maximum combustion capacity of the fourth stage or the third stage. Similarly, restricting the combustion capacity of the second burner 3 2 to below the capacity of the second stage means that even if the required combustion amount exceeds the maximum combustion capacity of the second stage, the combustion amount of the second burner 3 2 is restricted to below the maximum combustion capacity of the second stage.

[0030] In addition, the resonance sound is more likely to occur as the first combustion chamber 11 1 cools down, and is less likely to occur as the first combustion chamber 11 1 warms up. Therefore, even after the first combustion chamber 11 1 warms up and the resonance sound becomes less likely to occur, the priority operation control is prevented from being continued unnecessarily. The predetermined period for executing the priority operation control is set shorter as the combustion amount of the first burner 3 1 is larger according to the combustion amount. More specifically, the limit time, which is the length of the predetermined period for executing the priority operation control in the discrimination process in STEP5, is 15 seconds if the gas type is 13A and the exhaust resistance is small, 20 seconds if the gas type is 13A and the exhaust resistance is large, 10 seconds if the gas type is LP and the exhaust resistance is small, and 15 seconds if the gas type is LP and the exhaust resistance is large when the combustion capacity of the first burner 3 1 is the first-stage capacity. When the combustion capacity of the first burner 3 1 is the second-stage capacity, it is set 2 seconds shorter than the above-mentioned number of seconds. When the combustion capacity of the first burner 3 1 is the third-stage capacity, it is set 4 seconds shorter than the above-mentioned number of seconds. When the combustion capacity of the first burner 3 1 is the fourth-stage capacity, it is set 6 seconds shorter than the above-mentioned number of seconds. Similarly, the limit time in the discrimination process in STEP6 is 25 seconds if the gas type is 13A and the exhaust resistance is small, 30 seconds if the gas type is 13A and the exhaust resistance is large, 20 seconds if the gas type is LP and the exhaust resistance is small, and 25 seconds if the gas type is LP and the exhaust resistance is large when the combustion capacity of the first burner 3 1 is the first-stage capacity. When the combustion capacity of the first burner 3 1 is the second-stage capacity, it is set 4 seconds shorter than the above-mentioned number of seconds. When the combustion capacity of the first burner 3 1 is the third-stage capacity, it is set 6 seconds shorter than the above-mentioned number of seconds. When the combustion capacity of the first burner 3 1 is the fourth-stage capacity, it is set 8 seconds shorter than the above-mentioned number of seconds. When the combustion capacity of the first burner 3 1 is the fifth-stage capacity, it is set 10 seconds shorter than the above-mentioned number of seconds. In addition, during the priority operation control, the first burner 3 1When the combustion capacity changes, increase or decrease the limit time according to the time ratio of the combustion capacity before the change and after the change.

[0031] In addition, as shown by the phantom line in Fig. 1, it is also possible to provide a temperature sensor 14, which is a combustion chamber temperature detection means for detecting the temperature of the first combustion chamber 11. 1 In this case, instead of STEP5 and STEP6, or as a step to proceed when it is determined as "NO" in STEP5 and STEP6, a step for determining whether or not the detected temperature of the temperature sensor 14 has reached a predetermined temperature at which it is difficult for the resonance sound to occur is provided, and when the detected temperature of the temperature sensor 14 reaches the predetermined temperature or higher, the priority operation control may be terminated and the normal simultaneous operation may be shifted to.

[0032] As described above, the embodiments of the present invention have been described with reference to the drawings, but the present invention is not limited thereto. For example, in the above embodiment, the operation to be prioritized in the priority operation control is the heating operation only during the execution of the mist operation, but the heating operation may be prioritized also during the execution of the bathroom heating operation so that the user in the bathroom is not exposed to cold air. Further, when switching from the state of executing only the heating operation to the state of executing the simultaneous operation, the resonance sound is particularly likely to occur when the second burner 3 2 is burning with the maximum combustion capacity of the third stage and the first burner 3 1 is also burning with the maximum combustion capacity of the fifth stage. Therefore, it may be a condition for performing the priority operation control that there is a request to burn both the first and second burners 3 1 , 3 2 with the maximum combustion capacity.

Explanation of reference numerals

[0033] 11 1 … First combustion chamber, 11 2 … Second combustion chamber, 14... Temperature sensor (combustion chamber temperature detection means), 2 1 … First heat exchanger, 2 2 … Second heat exchanger, 3 1 … First burner, 3 2…Second burner, 4…Combustion fan, 5…Controller (control means), 67…Hot water supply terminal, 7…Heating circuit, 71…Bathroom heating device (heating terminal), 72…Mist device (heating terminal), 73…Floor heating panel (heating terminal).

Claims

1. A combined heat source machine comprising a first heat exchanger for heating water supplied to a hot water supply terminal, a first burner serving as a heat source for the first heat exchanger, a first combustion chamber in which the first heat exchanger and the first burner are disposed, a second heat exchanger for heating a heat medium circulated in a heating circuit, a second burner serving as a heat source for the second heat exchanger, a second combustion chamber in which the second heat exchanger and the second burner are disposed, a combustion fan for supplying combustion air to the first combustion chamber and the second combustion chamber, and control means. The combined heat source machine is capable of performing a hot water supply operation of burning the first burner and supplying the water heated by the first heat exchanger to the hot water supply terminal, a heating operation of burning the second burner and heating the heat medium in the second heat exchanger while circulating the heat medium in the heating circuit, and a simultaneous operation of performing the hot water supply operation and the heating operation simultaneously. In this case, when switching from a state of performing only the heating operation to a state of performing the simultaneous operation, the control means performs priority operation control for restricting the other operation so that the combustion amount of the burner corresponding to the other operation becomes equal to or less than the required combustion amount by prioritizing either the heating operation or the hot water supply operation for a predetermined period. The operation prioritized in the priority operation control is determined based on the type of the heating terminal operating in the heating operation. A combined heat source machine characterized by this.

2. When the heating terminal operating in the heating operation is a mist device that sprays water heated by heat exchange with the heat medium circulating in the heating circuit into the bathroom, the operation prioritized in the priority operation control is the heating operation. The combined heat source machine according to Claim 1, characterized by this.

3. The predetermined period for performing the priority operation control is set to be shorter as the combustion amount of the first burner is larger, corresponding to the combustion amount. The combined heat source machine according to Claim 1 or 2, characterized by this.

4. The combined heat source machine according to Claim 1 or 2, further comprising combustion chamber temperature detection means for detecting the temperature of the first combustion chamber, and ending the priority operation control when the detected temperature of the combustion chamber temperature detection means becomes equal to or higher than a predetermined temperature.

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