Heater / hot water supplying device

Abstract

To suppress generation of failure caused in particular by air bubbles remaining in an internal circulation passage in a heater / hot water supplying device.SOLUTION: A heater / hot water supplying device includes: an external circulation passage for circulating a heating medium in a heating terminal; an internal circulation passage including a common portion with the external circulation passage and for circulating the heating medium in hot water supply heat exchanger; and exhaust means capable of exhausting air bubbles included in the heating medium. Also, it can switch between a heating operation state of circulating the heating medium in the external circulation passage, a hot water supplying operation state of circulating the heating medium in the internal circulation passage, and a simultaneous operation state of circulating the heating medium in both the external circulation passage and the internal circulation passage, by circulation switching means (three-way valve). After injecting the heating medium, a test operation is executed for urging the exhaust of air bubbles by circulating the heating medium. This test operation includes: an external circulation passage exhaust step of urging the exhaust of air bubbles from the external circulation passage; and an internal circulation passage exhaust step of urging the exhaust of air bubbles from the internal circulation passage. Then, in the internal circulation passage exhaust step, an operation is performed for switching from the hot water supply operation state of the simultaneous operation state to the heating operation state during the actuation of a circulation pump.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a heating and hot water supply device that can perform a heating operation in which a heat medium is circulated to a heating terminal using a circulation pump to provide heating, and a hot water supply operation in which a shared heat medium is circulated to a hot water heat exchanger and water supplied to the hot water heat exchanger is heated by heat exchange with the heat medium. [Background technology]

[0002] A heating and hot water supply system is known that can perform a heating operation by circulating a heat medium heated by a heating means such as a burner to a heating terminal using a circulation pump, and can also perform a hot water supply operation by circulating a shared heat medium through a hot water heat exchanger and heating water supplied to the hot water heat exchanger through heat exchange with the heat medium (see, for example, Patent Document 1). This heating and hot water supply system includes an external circulation path that circulates the heat medium to the heating terminal and an internal circulation path that includes a common section with the external circulation path and circulates the heat medium to the hot water heat exchanger. It is possible to switch between a heating operation state in which the heat medium is circulated through the external circulation path, a hot water operation state in which the heat medium is circulated through the internal circulation path, and a simultaneous operation state in which the heat medium is circulated through both the external circulation path and the internal circulation path using a circulation switching means such as a three-way valve. The common section also includes a temperature sensor that detects the temperature of the heat medium, and the heating of the heating means is controlled based on the temperature detected by the temperature sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-185082 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in these hot water heating and discharging systems, even though the heating medium is injected after installation, air remains in the external and internal circulation paths, and the remaining air circulates along with the heating medium as bubbles, which can cause malfunctions. For example, the heat of the heating means may concentrate in the heating medium around the bubbles, causing it to boil partially, turning the heating means off. When bubbles pass through the temperature sensor, the detected temperature drops, turning the heating means on. Or, the temperature detected by the temperature sensor becomes unstable, causing the heating means to repeatedly turn on and off. In particular, if air bubbles remain in the internal circulation path, the ability to regulate the temperature of the heating medium during hot water supply operation is disrupted, resulting in unstable hot water temperature and reduced user comfort. Therefore, the negative impact of remaining air bubbles is greater than that of the external circulation path.

[0005] This invention has been made in response to the above-mentioned problems of conventional technology, and aims to provide technology that can suppress the occurrence of problems caused by air bubbles remaining in the internal circulation path in heating and hot water supply devices. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the heating and hot water supply device of the present invention employs the following configuration: <First aspect> A heating and hot water supply device capable of performing a heating operation in which a heat medium is circulated to a heating terminal by a circulation pump for heating, and a hot water supply operation in which the shared heat medium is circulated to a hot water heat exchanger and water supplied to the hot water heat exchanger is heated by heat exchange with the heat medium, an external circulation path for circulating the heat medium to the heating terminal; an internal circulation path that includes a common portion with the external circulation path and circulates the heat medium to the hot water heat exchanger; a heating means capable of heating the heat medium in the common portion; a temperature sensor that detects the temperature of the heat medium in the common portion; a circulation switching means capable of switching among a heating operation state in which the heat medium is circulated in the external circulation path, a hot water supply operation state in which the heat medium is circulated in the internal circulation path, and a simultaneous operation state in which the heat medium is circulated in both the external circulation path and the internal circulation path; an exhaust means capable of discharging bubbles contained in the heat medium; a test operation control means for controlling the execution of a test operation that circulates the heat medium after the heat medium is injected to promote the discharge of the air bubbles; Equipped with The test operation includes an external circulation path exhaust step of facilitating the discharge of the air bubbles from the external circulation path, and an internal circulation path exhaust step of facilitating the discharge of the air bubbles from the internal circulation path, In the internal circulation path exhaust step, the circulation switching means performs an operation of switching from the hot water supply operation state or the simultaneous operation state to the heating operation state while the circulation pump is operating. It is characterized by:

[0007] In the heating and hot water supply system of the first aspect, the system is in hot water supply operation or simultaneous operation while the circulation pump is operating, causing bubbles remaining in the hot water heat exchanger of the internal circulation path to circulate along with the heat transfer medium. When the system switches to heating operation while the bubbles are passing through the common section between the external and internal circulation paths, the bubbles are guided to the heating terminal of the external circulation path, thereby facilitating the discharge of bubbles from the internal circulation path. Because the external circulation path generally holds a larger amount of heat transfer medium than the internal circulation path, circulating bubbles through the external circulation path takes longer to reach the heating means and temperature sensor in the common section than circulating through the internal circulation path, thereby lengthening the cycle of bubble-related malfunctions (disturbances in the heat transfer medium temperature regulation performance). Alternatively, the movement of bubbles from the internal circulation path to the external circulation path disperses the bubbles rather than remaining in the internal circulation path, reducing the ratio of bubbles to the amount of heat transfer medium, thereby reducing the frequency of bubble-related malfunctions.

[0008] <Second aspect> In the heating and hot water supply device of the first aspect, In the internal circulation path exhaust step, the circulation switching means performs an operation of switching from the hot water supply operation state to the heating operation state while the circulation pump is operating. It is characterized by:

[0009] In this second aspect of the heating and hot water device, the system is in hot water operation mode while the circulation pump is operating, so that the entire amount of circulating heat medium flows through the hot water heat exchanger in the internal circulation path, making it easier for air bubbles to be pushed out of the hot water heat exchanger, thereby further reducing the amount of air bubbles remaining in the internal circulation path.

[0010] <Third aspect> In the heating and hot water supply apparatus of the first aspect or the second aspect, In the external circulation path exhaust step, the circulation pump is operated while the circulation switching means maintains the heating operation state, The test operation control means executes the internal circulation path exhaust process after the external circulation path exhaust process is executed. It is characterized by:

[0011] In the heating and hot water supply device of the third aspect, by first performing the external circulation path exhaust step to exhaust air bubbles from the external circulation path (heating terminal) in advance, when the internal circulation path exhaust step switches to the heating operation state, it is possible to prevent air bubbles from flowing from the heating terminal into the common area between the external circulation path and the internal circulation path. Also, when the internal circulation path exhaust step is in the simultaneous operation state, it is possible to prevent air bubbles from flowing from the heating terminal into the common area, so it is possible to efficiently exhaust air bubbles from the internal circulation path.

[0012] <Fourth aspect> In the heating and hot water supply device of any one of the first to third aspects, The test operation control means executes the internal circulation path exhaust process a plurality of times by varying the timing of switching to the heating operation state by the circulation switching means or the flow rate at which the heat medium is circulated by the circulation pump. It is characterized by:

[0013] In the heating and hot water supply device of the fourth aspect, the timing of switching to the heating operation state varies during multiple internal circulation path exhaust processes, which prevents the occurrence of a situation in which the air bubbles in the hot water heat exchanger circulate together with the heat medium, pass through the common part, and return to the hot water heat exchanger, and then the system switches to the heating operation state repeatedly. Also, the flow rate of the circulating heat medium varies during multiple internal circulation path exhaust processes, which changes the time it takes for the air bubbles in the hot water heat exchanger to circulate together with the heat medium, pass through the common part, and return to the hot water heat exchanger. Therefore, by switching to the heating operation state before the air bubbles return to the hot water heat exchanger, it becomes possible to guide the air bubbles to the external circulation path.

[0014] <Fifth aspect> In any one of the heating and hot water supply apparatuses of the first to fourth aspects, the test operation includes a heating and exhausting step of circulating the heat medium heated by the heating means through at least one of the external circulation path and the internal circulation path, The test operation control means executes the heating exhaust step after executing the external circulation path exhaust step and the internal circulation path exhaust step. It is characterized by:

[0015] In the heating and hot water supply device of the fifth aspect, even when the external circulation path exhaust step or the internal circulation path exhaust step is performed, the air (nitrogen and oxygen) dissolved in the heat medium can be turned into bubbles by heating the heat medium, thereby facilitating its discharge. As a result, bubbles are less likely to form even when the heat medium is heated during heating operation or hot water supply operation during actual use of the heating and hot water supply device, thereby suppressing the occurrence of problems caused by bubbles.

[0016] <Sixth aspect> In the heating and hot water supply device of the fifth aspect, In the heating and exhausting step, the heating means heats the heat medium until the temperature detected by the temperature sensor reaches a predetermined temperature, The predetermined temperature is set to the higher of the target temperature of the heat medium in the heating operation and the target temperature of the heat medium in the hot water supply operation. It is characterized by:

[0017] In the heating and hot water supply device of this sixth aspect, the heat transfer medium is heated to the higher temperature expected when the heating and hot water supply device is used, thereby pre-forming the dissolved air into bubbles. This reduces the number of bubbles that are generated from the heat transfer medium when heated during actual use, thereby suppressing the occurrence of problems caused by bubbles. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram showing the configuration of a heating and hot water supply device 1 of the present embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of a three-way valve 29 of the present embodiment. [Figure 3] FIG. 2 is an explanatory diagram showing the configuration of a heating terminal according to the present embodiment. [Figure 4] FIG. 3 is an explanatory diagram showing a test run sequence in the heating and hot water supply device 1 of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Figure 1 is an explanatory diagram showing the configuration of a heating and hot water supply system 1 of this embodiment. As shown in the figure, the heating and hot water supply system 1 is enclosed in a housing 2 and equipped with a combustion unit 4 incorporating a burner 3 that burns a mixture of fuel gas and combustion air. A combustion fan 5 is connected to the combustion unit 4, and the mixture gas is fed by this combustion fan 5.

[0020] A confluence 6 is provided on the intake side of the combustion fan 5, where an air supply passage 7 that supplies combustion air and a gas supply passage 8 that supplies fuel gas converge. The gas supply passage 8 is provided with an on-off valve (not shown) that opens and closes the gas supply passage 8, and a zero governor 9 that reduces the pressure of the fuel gas pumped from upstream to atmospheric pressure. A control valve is built into the confluence 6, making it possible to adjust the ratio of combustion air and fuel gas flowing into the combustion fan 5. When the combustion fan 5 is driven, the air inside the housing 2 and the fuel gas downstream of the zero governor 9 on the gas supply passage 8 are drawn into the combustion fan 5 at a predetermined ratio through the confluence 6, and the mixed gas is sent to the combustion unit 4.

[0021] In the combustion unit 4, the mixed gas is combusted in the built-in burner 3. In the illustrated example, the mixed gas is ejected downward from the burner 3, forming a downward flame, and the combustion exhaust is sent downward. The combustion fan 5 is electrically connected to a controller 40 that controls the overall operation of the heating and hot water supply device 1, and the controller 40 controls the amount of combustion in the burner 3 by changing the rotation speed of the combustion fan 5 according to the amount of heat required.

[0022] The combustion unit 4 is also provided with an ignition plug 11 that generates a spark in the burner 3 by discharging a high voltage, a flame rod 12 that detects the flame (ignition) of the burner 3, and a check valve 13 that prevents backflow from the combustion unit 4 to the combustion fan 5. The ignition plug 11 and the flame rod 12 are electrically connected to the controller 40.

[0023] A first heat exchanger 15 is provided below the burner 3, and a second heat exchanger 16 is provided below the first heat exchanger 15. The combustion exhaust gas generated by combustion in the burner 3 is sent downward and passes through the first heat exchanger 15 and the second heat exchanger 16 in that order. At this time, the first heat exchanger 15 recovers sensible heat from the combustion exhaust gas, and the second heat exchanger 16 recovers latent heat from the combustion exhaust gas.

[0024] The combustion exhaust gas that has passed through the first heat exchanger 15 and the second heat exchanger 16 passes through an exhaust duct 17 and is discharged from an exhaust port 18 that protrudes from the top of the housing 2. In the illustrated example, an air intake port 19 is provided at the top of the housing 2, and air taken into the housing 2 from the air intake port 19 is supplied to the junction 6 through the air supply path 7.

[0025] The upstream side of the first heat exchanger 15 is connected to the downstream side of the second heat exchanger 16. The downstream side of the first heat exchanger 15 is connected to the upstream side of a heating terminal (described later) via a feed passage 21, and the upstream side of the second heat exchanger 16 is connected to the downstream side of the heating terminal (described later) via a return passage 22. The return passage 22 is provided with a circulation pump 23 that sends the heat medium toward the second heat exchanger 16 and a return temperature sensor 24 that detects the temperature of the heat medium flowing into the second heat exchanger 16 (hereinafter referred to as the return temperature). The circulation pump 23 and the return temperature sensor 24 are electrically connected to the controller 40. Note that, although the heating and hot water device 1 of this embodiment uses hot water as the heat medium, the heat medium is not limited to hot water and may be silicone oil or the like.

[0026] The heat transfer medium sent to the second heat exchanger 16 by the operation of the circulation pump 23 is preheated in the second heat exchanger 16 by latent heat recovered from the combustion exhaust gas of the burner 3, and then sent to the first heat exchanger 15. In the first heat exchanger 15, the heat transfer medium is heated by sensible heat recovered from the combustion exhaust gas of the burner 3, and the high-temperature heat transfer medium is supplied to the heating terminal through the supply passage 21. A supply temperature sensor 25 is provided in the supply passage 21 to detect the temperature of the heat transfer medium flowing out of the first heat exchanger 15 (hereinafter referred to as the supply temperature), and the supply temperature sensor 25 is electrically connected to the controller 40. The controller 40 determines the required amount of heat based on the temperature detected by the supply temperature sensor 25 and controls combustion in the burner 3. The supply temperature sensor 25 in this embodiment corresponds to the "temperature sensor" in the present invention. The burner 3, the first heat exchanger 15, and the second heat exchanger 16 in this embodiment correspond to the "heating means" in the present invention.

[0027] The heat transfer medium that has passed through the heating terminal returns to the circulation pump 23 through the return passage 22, and is then sent again to the second heat exchanger 16 for circulation. In this embodiment, the circulation pump 23 is configured to send the heat transfer medium while maintaining a constant rotation speed. In addition, an air vent 26 capable of discharging bubbles (air) contained in the heat transfer medium is provided at the upper end of the outgoing passage 21. The air vent 26 in this embodiment corresponds to the "exhaust means" of the present invention.

[0028] As is well known, a typical float-type air vent 26 has a valve port and houses a float within the valve chamber. When the heat transfer medium flows into the valve chamber, the float rises to the surface and blocks the valve port, closing the valve. When air bubbles contained in the heat transfer medium rise and flow into the valve chamber, the liquid level drops, causing the float to separate from the valve port, opening the valve. The air inside the valve chamber is then expelled, causing the liquid level to rise, returning the valve to its closed state. While the circulation pump 23 is operating, the air bubbles circulate with the heat transfer medium, making them difficult to expel. However, when the circulation pump 23 is stopped, the air bubbles rise to the surface, making them easier to expel.

[0029] Furthermore, a branch passage 27 branches off from the supply passage 21 downstream of the supply temperature sensor 25 and is connected to the return passage 22 upstream of the circulation pump 23. A hot water heat exchanger 28 is provided in this branch passage 27. A three-way valve 29 is provided at the connection between the branch passage 27 and the return passage 22 and is electrically connected to a controller 40. The configuration of the three-way valve 29 will be described later using a separate drawing. The three-way valve 29 can switch between circulating the heat medium flowing out of the first heat exchanger 15 through a route passing through the heating terminal (hereinafter referred to as the external circulation route), a route passing through the hot water heat exchanger 28 (hereinafter referred to as the internal circulation route), or both the external circulation route and the internal circulation route. The three-way valve 29 in this embodiment corresponds to the "circulation switching means" of the present invention. In addition, in this embodiment, the section from the downstream side of the connection point with the branch passage 27 in the return passage 22 to the upstream side of the connection point with the branch passage 27 in the outward passage 21 corresponds to the ``common section'' of the present invention.

[0030] The hot water heat exchanger 28 is a liquid-liquid heat exchanger, and is connected to a water supply passage 30 and a hot water outlet passage 31. The clean water supplied to the hot water heat exchanger 28 through the water supply passage 30 is heated by heat exchange with a heat medium in the hot water heat exchanger 28, and the hot water flows out into the hot water outlet passage 31. The water supply passage 30 is provided with a water volume sensor 32 that measures the flow rate of the clean water flowing into the heating and hot water supply device 1, a water volume servo 33 that adjusts the flow rate of the clean water, and a water supply temperature sensor 34 that detects the temperature of the clean water. The hot water outlet passage 31 is provided with a heat exchanger outlet hot water temperature sensor 35 that detects the temperature of the hot water immediately after it flows out of the hot water heat exchanger 28. The water volume sensor 32, the water volume servo 33, the water supply temperature sensor 34, and the heat exchanger outlet hot water temperature sensor 35 are electrically connected to a controller 40.

[0031] In the heating and hot water supply apparatus 1 of this embodiment, a bypass passage 36 connects the downstream side of the water supply passage 30 relative to the water supply temperature sensor 34 and the downstream side of the hot water outlet passage 31 relative to the heat exchanger hot water outlet temperature sensor 35. A portion of the clean water flowing into the heating and hot water supply apparatus 1 can pass through the bypass passage 36 without being supplied to the hot water heat exchanger 28, and the remainder is supplied to the hot water heat exchanger 28. The hot water heated in the hot water heat exchanger 28 is mixed with the clean water that has passed through the bypass passage 36 and flows out of the heating and hot water supply apparatus 1. A bypass servo 37 is provided at the connection between the bypass passage 36 and the hot water outlet passage 31, and the bypass servo 37 is electrically connected to the controller 40. The mixing ratio of the hot water heated in the hot water heat exchanger 28 and the clean water that has passed through the bypass passage 36 can be changed by the bypass servo 37.

[0032] An outlet hot water temperature sensor 38 that detects the temperature of the hot water flowing out from the heating and hot water supply apparatus 1 is provided downstream of the bypass servo 37 in the hot water outlet passage 31, and the outlet hot water temperature sensor 38 is connected to the controller 40. As described above, when part of the clean water in the water supply passage 30 passes through the bypass passage 36 without passing through the hot water heat exchanger 28 and joins the hot water outlet passage 31, the temperature detected by the outlet hot water temperature sensor 38 will naturally be lower than the temperature detected by the heat exchanger outlet hot water temperature sensor 35, and by adjusting the mixing ratio with the bypass servo 37, it is possible to suppress temperature fluctuations in the hot water flowing out from the heating and hot water supply apparatus 1.

[0033] Furthermore, a hot water supply remote control 41 and a heating remote control 42 are connected to the controller 40. The user can switch the hot water supply operation between ON and OFF and set the hot water temperature by operating the hot water supply remote control 41. The user can also instruct the heating operation to start or stop and set the heating temperature by operating the heating remote control 42.

[0034] 2 is a cross-sectional view showing the configuration of the three-way valve 29 of this embodiment. As shown in the figure, a valve chamber 50 that communicates in three directions is formed inside the three-way valve 29. In the example shown, the branch passage 27 is connected to the left of the valve chamber 50, the return passage 22 on the heating terminal side of its connection with the branch passage 27 (hereinafter referred to as the terminal-side return passage 22a) is connected to the right, and the return passage 22 on the second heat exchanger 16 side of its connection with the branch passage 27 (hereinafter referred to as the heat exchanger-side return passage 22b) is connected above.

[0035] Also housed within valve chamber 50 are a hot-water-side valve element 51 that opens and closes branch passage 27, and a heating-side valve element 52 that opens and closes terminal-side return passage 22a, and these hot-water-side valve element 51 and heating-side valve element 52 are attached facing opposite to each other to a moving shaft 53 that can move back and forth in the left and right direction. Moving shaft 53 is driven by a drive mechanism 54, and in this embodiment, drive mechanism 54 converts the rotation of a built-in stepping motor into axial (left and right) movement of moving shaft 53.

[0036] 2(a) shows a state in which moving shaft 53 has moved leftward, causing hot water supply side valve element 51 to close branch passage 27 and heating side valve element 52 to open terminal side return passage 22a. At this time, the heat medium flowing out of first heat exchanger 15 due to operation of circulation pump 23 circulates through the heating terminal (external circulation path) without being distributed to hot water supply heat exchanger 28, resulting in heating operation.

[0037] On the other hand, when the moving shaft 53 is moved to the right by the driving of the drive mechanism 54, the heating-side valve element 52 closes the terminal-side return passage 22a, and the hot-water-side valve element 51 opens the branch passage 27, as shown in Figure 2(b). At this time, the heat medium flowing out of the first heat exchanger 15 due to the operation of the circulation pump 23 circulates through the hot-water heat exchanger 28 (internal circulation path) without being distributed to the heating terminal, and the unit enters a hot-water operation state.

[0038] Furthermore, as shown in FIG. 2(c), by stopping the moving shaft 53 midway between the heating operation state of FIG. 2(a) and the hot water supply operation state of FIG. 2(b), both the branch passage 27 and the terminal-side return passage 22a are opened. At this time, the heat transfer medium flowing out of the first heat exchanger 15 due to the operation of the circulation pump 23 circulates to both the heating terminal (external circulation path) and the hot water supply heat exchanger 28 (internal circulation path), resulting in a simultaneous operation state. Note that the "heating operation state," "hot water supply operation state," and "simultaneous operation state" in this embodiment merely represent the switching state of the three-way valve 29 and are unrelated to whether heating or hot water supply is actually performed. Therefore, heating of the heat transfer medium by combustion in the burner 3 may or may not be performed.

[0039] Fig. 3 is an explanatory diagram showing the configuration of the heating terminal of this embodiment. The example shown in Fig. 3 is equipped with a low-loss header 60 capable of temporarily storing the heat transfer medium, and the supply passage 21 and the return passage 22 are connected to the low-loss header 60. When the heat transfer medium flowing out of the first heat exchanger 15 is circulated to the external circulation path by the three-way valve 29, the heat transfer medium circulates through the low-loss header 60. In addition to the primary circuit formed by the supply passage 21 and the return passage 22, the upstream and downstream sides of a heating passage 61 are connected to the low-loss header 60 as a secondary circuit. The low-loss header 60 is configured to reduce pressure loss in the primary circuit due to the flow resistance of the secondary circuit and ensure the circulation flow rate of the heat transfer medium in the primary circuit.

[0040] As shown in the figure, the heating passage 61 in this embodiment branches into two, a first heating passage 61a and a second heating passage 61b, and then merges back together. The first heating passage 61a is provided with a first pump 62 that circulates the heat transfer medium from the low-loss header 60 into the first heating passage 61a and a first heat radiating portion 63a built into the baseboard heater 63. The baseboard heater 63 heats by radiating heat as the heat transfer medium passes through the first heat radiating portion 63a due to the operation of the first pump 62. The second heating passage 61b is provided with a second pump 64 that circulates the heat transfer medium from the low-loss header 60 into the second heating passage 61b and a second heat radiating portion 65a built into the air handling unit 65. The air handling unit 65 heats by radiating heat as the heat transfer medium passes through the second heat radiating portion 65a due to the operation of the second pump 64. Note that examples of the heating terminal incorporating the first heat dissipation section 63a and the second heat dissipation section 65a are not limited to the baseboard heater 63 and the air handling unit 65, but may also be a floor heater or a fan convector.

[0041] In the example shown in Fig. 3, a dirt trap 66 for removing foreign matter contained in the heating medium is provided downstream of the confluence of the first heating passage 61a and the second heating passage 61b in the heating passage 61. In addition, an air separator 67 for discharging air bubbles (air) contained in the heating medium is provided upstream of the branching point of the first heating passage 61a and the second heating passage 61b in the heating passage 61. As is well known, the air separator 67 generally includes a mesh, and as the heating medium passes through the mesh, air bubbles contained in the heating medium are adsorbed by the mesh and discharged. Therefore, circulating the heating medium promotes the discharge of air bubbles in the air separator 67.

[0042] In addition, an expansion tank 69 is connected to the air separator 67 of this embodiment via a connecting passage 68, so that when the heat transfer medium expands due to a temperature rise, the expansion tank 69 absorbs the expansion. Furthermore, an injection passage 70 is connected to the connecting passage 68, and this injection passage 70 is provided with an injection valve 71 that opens and closes the injection passage 70. In the heating and hot water supply device 1 of this embodiment, after installing the heating and hot water supply device 1, an installer connects a heat transfer medium supply pipe (not shown) to the injection passage 70 and manually opens the injection valve 71 to inject the heat transfer medium. In addition, the supply passage 21 of this embodiment is provided with a pressure sensor 72 that detects the pressure of the heat transfer medium in the supply passage 21, and the heat transfer medium is injected until the pressure detected by the pressure sensor 72 reaches a predetermined pressure.

[0043] In this type of heating and hot water device 1, even after the injection of the heat medium is complete, air remains in the first heat exchanger 15, the second heat exchanger 16, the supply passage 21, the return passage 22, the branch passage 27, the hot water heat exchanger 28, the low-loss header 60, etc., and the remaining air may turn into bubbles and circulate along with the heat medium, causing problems. For example, when the bubbles pass through the first heat exchanger 15, heat may concentrate in the heat medium around the bubbles, causing partial boiling and extinguishing the burner 3; when the bubbles pass through the supply temperature sensor 25, the detected temperature may drop, causing the burner 3 to ignite; or the detected temperature of the supply temperature sensor 25 may become unstable, causing the burner 3 to repeatedly turn on and off. In particular, if air bubbles remain in the internal circulation path that circulates the heat medium to the hot water heat exchanger 28, the ability to adjust the temperature of the heat medium during hot water supply operation is disrupted, causing the temperature of the hot water flowing out of the heating and hot water supply device 1 to become unstable and reducing user comfort, so the adverse effects of remaining air bubbles are greater than in the external circulation path that circulates the heat medium to the heating terminal. Therefore, in the heating and hot water supply device 1 of this embodiment, in order to prevent problems caused by air bubbles remaining in the internal circulation path in particular, after installation of the heating and hot water supply device 1, a trial run is performed to circulate the heat medium as follows and promote the removal of air bubbles.

[0044] FIG. 4 is an explanatory diagram showing the test run sequence of the heating and hot water supply device 1 of this embodiment. The test run is controlled by the controller 40, which has a function corresponding to the "test run control means" of the present invention. First, in the injection preparation process of STEP 1, the position of the three-way valve 29 is moved to the simultaneous operation state of FIG. 2(c) based on the operation of a test run button (not shown). In the heating and hot water supply device 1 of this embodiment, the initial position of the three-way valve 29 is set to the heating operation state of FIG. 2(a), so the drive mechanism 54 is driven to switch from the heating operation state to the simultaneous operation state.

[0045] In the injection process of STEP 2, the three-way valve 29 is maintained in the simultaneous operation state while the installer of the heating and hot water supply apparatus 1 is injecting the heat medium. As described above, the installer injects the heat medium by connecting the heat medium supply pipe to the injection passage 70 and manually opening the injection valve 71. By keeping the three-way valve 29 in the simultaneous operation state, the injected heat medium flows not only into the external circulation path but also into the internal circulation path (hot water heat exchanger 28), thereby reducing the amount of air remaining in the hot water heat exchanger 28 when the injection of the heat medium is completed. In the heating and hot water supply apparatus 1 of this embodiment, the injection passage 70 is connected to the connection passage 68 branching from the heating passage 61. However, the connection position of the injection passage 70 is not limited thereto, and the injection passage 70 may be connected to the supply passage 21 or the return passage 22.

[0046] In the pressure confirmation process of STEP 3, the pressure detected by the pressure sensor 72 described above, which detects the pressure of the heat medium in the outflow passage 21, is confirmed, and if the detected pressure reaches or exceeds a predetermined pressure and continues for a certain period of time, the position of the three-way valve 29 is switched from the simultaneous operation state of Fig. 2(c) to the heating operation state of Fig. 2(a). Note that the installer may be notified by means of a display or sound that the pressure detected by the pressure sensor 72 has reached or exceeded the predetermined pressure and continued for a certain period of time.

[0047] In the external circulation path exhaust process of STEP 4, the circulation pump 23 is operated to expel air bubbles from the external circulation path that circulates the heat transfer medium to the heating terminal. In the heating and hot water supply device 1 of this embodiment, as described above, the heating terminal (heating passage 61) is equipped with an air separator 67 that can expel air bubbles in the heat transfer medium by circulating (passing) the heat transfer medium. While it is common for the heating terminal (heating passage 61) to be equipped with an air separator 67, specifications vary depending on the type of heating terminal, so not all heating terminals are equipped with an air separator 67. In some cases, an air vent (configured to expel air bubbles when the heat transfer medium circulation is stopped) is equipped instead of the air separator 67. Therefore, in the external circulation path exhaust process of this embodiment, assuming that the heating terminal does not have an air separator 67, an air vent (air vent 26 built into the heating and hot water supply device 1 or a separate air vent installed in the heating terminal) can be used to adequately expel air bubbles.

[0048] In the illustrated example, first, the circulation pump 23 is operated for 20 seconds, followed by a 10-second stop, and this intermittent operation is repeated three times. As mentioned above, since it is difficult for air bubbles to be discharged from the air vent 26 when the circulation pump 23 is operating, by repeatedly operating the circulation pump 23 intermittently, the air bubbles are circulated (moved) along with the heat transfer medium while the circulation pump 23 is operating, and the air bubbles are raised to the surface while the circulation pump 23 is stopped, thereby facilitating their discharge. Note that, in the case where an air separator 67 is provided at the heating terminal, as in the heating and hot water supply device 1 of this embodiment, the first pump 62 and the second pump 64 can be operated together with the circulation pump 23 to facilitate the discharge of air bubbles from the heating terminal by the air separator 67.

[0049] Next, the circulation pump 23 is operated for 15 seconds, then stopped for 10 seconds, and this cycle is repeated three times. Furthermore, the circulation pump 23 is operated for 10 seconds, then stopped for 10 seconds, and this cycle is repeated three times. By varying the operation time of the circulation pump 23 in this way, the timing of the circulation of bubbles, which would otherwise return to positions where they are difficult to discharge if the operation time were constant, can be shifted, allowing the bubbles to rise to positions where they are easy to discharge, thereby facilitating their discharge. In the heating and hot water supply device 1 of this embodiment, the rotation speed of the circulation pump 23 is maintained constant and the operation time of the circulation pump 23 is varied. Alternatively, the operation time of the circulation pump 23 may be kept constant and the rotation speed of the circulation pump 23 may be varied to shift the timing of the circulation of bubbles.

[0050] In the internal circulation path exhaust process in STEP 5, the position of three-way valve 29 is switched while circulation pump 23 is operating, thereby promoting the discharge of air bubbles from the internal circulation path that circulates the heat medium to hot water heat exchanger 28. In the illustrated example, while circulation pump 23 is continuously operated, the position of three-way valve 29 is switched from the heating operation state of Fig. 2(a) to the hot water operation state of Fig. 2(b) and maintained for 15 seconds, and then switched back to the heating operation state and maintained for 5 seconds, and this is repeated two times. By switching the position of the three-way valve 29 in this manner, for example, when the position of the three-way valve 29 is in the hot water operation state, if the air bubbles remaining in the hot water heat exchanger 28 circulate together with the heat medium and pass through the second heat exchanger 16 and the first heat exchanger 15 before reaching the connection between the forward passage 21 and the branch passage 27, and the position of the three-way valve 29 is switched to the heating operation state, the air bubbles will not return to the hot water heat exchanger 28 (internal circulation path) but will be guided to the heating terminal (external circulation path), thereby facilitating the discharge of the air bubbles from the internal circulation path.

[0051] As described above, residual air bubbles have a greater adverse effect on the internal circulation path than on the external circulation path. Therefore, by guiding the air bubbles to the external circulation path, problems caused by the air bubbles remaining in the internal circulation path can be suppressed. Furthermore, since the external circulation path of this embodiment is provided with an air separator 67 in the heating passage 61, the air bubbles guided to the external circulation path can be discharged by the air separator 67 by operating the first pump 62 or the second pump 64. Even if the external circulation path does not have an air separator 67, the external circulation path generally holds a larger amount of heat transfer medium than the internal circulation path. Therefore, by circulating the external circulation path, it takes longer for the air bubbles to reach the first heat exchanger 15 and the feed temperature sensor 25 than by circulating the internal circulation path. This lengthens the period during which the adjustment performance of the heat transfer medium temperature is disturbed by the air bubbles. Alternatively, by moving the bubbles from the internal circulation path to the external circulation path, the bubbles disperse rather than remaining in the internal circulation path, reducing the ratio of bubbles to the amount of heat transfer medium, and reducing the frequency at which the heat transfer medium temperature adjustment performance is disturbed due to bubbles.

[0052] In the external circulation path exhaust process of STEP 6, similar to STEP 4 described above, the circulation pump 23 is intermittently operated to circulate the air bubbles in the external circulation path together with the heat transfer medium, while promoting the discharge of the air bubbles from the air vent 26 (and air separator 67). However, in STEP 6, the operation time of the circulation pump 23 is not changed, and three sets of intermittent operation in which the circulation pump 23 is operated for 10 seconds and then stopped for 10 seconds are repeated. Note that the operation time of the circulation pump 23 may also be changed in STEP 6.

[0053] In the internal circulation path exhaust process of STEP 7, similar to the above-described STEP 5, the position of three-way valve 29 is switched while circulation pump 23 is operating to guide the air bubbles in the internal circulation path to the external circulation path, thereby promoting the discharge of air bubbles from the internal circulation path. However, in STEP 7, the position of three-way valve 29 is switched from the heating operation state to the hot water supply operation state and maintained for 10 seconds, then switched back to the heating operation state and maintained for 5 seconds, and this is repeated two times, so the time for which the hot water supply operation state is maintained is shorter than in STEP 5.

[0054] If the time for which the three-way valve 29 maintains the hot water operation state is constant, the air bubbles in the hot water heat exchanger 28 circulate with the heat medium, passing through the second heat exchanger 16 and the first heat exchanger 15. Each time the air bubbles return to the hot water heat exchanger 28, the three-way valve 29 is switched to the heating operation state, which may cause the air bubbles to remain in the hot water heat exchanger 28 indefinitely. Therefore, by varying the time for which the three-way valve 29 maintains the hot water operation state, the timing of the switch to the heating operation state changes. Therefore, by switching the three-way valve 29 to the heating operation state before the air bubbles return to the hot water heat exchanger 28, the air bubbles can be guided to the external circulation path. In the heating and hot water supply device 1 of this embodiment, the rotation speed of the circulation pump 23 is maintained constant and the time for which the three-way valve 29 maintains the hot water operation state is varied. Alternatively, the time for which the three-way valve 29 maintains the hot water operation state may be uniform, and the rotation speed of the circulation pump 23 may be varied. When the rotation speed of the circulation pump 23 is changed, the flow rate of the circulating heat medium changes, and accordingly, the time required for the air bubbles in the hot water heat exchanger 28 to circulate together with the heat medium and return to the hot water heat exchanger 28 via the second heat exchanger 16 and the first heat exchanger 15 changes.Therefore, by switching the position of the three-way valve 29 to the heating operation state before the air bubbles return to the hot water heat exchanger 28, it is possible to guide the air bubbles to the external circulation path.

[0055] In the external circulation path exhaust process of STEP 8, as in STEP 6, the circulation pump 23 is operated for 10 seconds and then stopped for 10 seconds, and this is repeated three times, thereby circulating the air bubbles in the external circulation path together with the heat transfer medium and promoting the discharge of the air bubbles from the air vent 26 (and air separator 67).

[0056] In the internal circulation path exhaust process in STEP 9, the time for which the three-way valve 29 is maintained in hot water operation mode is even shorter than in STEP 7. While the circulation pump 23 is operating, the position of the three-way valve 29 is switched from the heating operation mode to the hot water operation mode and maintained for 5 seconds, then switched back to the heating operation mode and maintained for 5 seconds; this is repeated two times to promote the expulsion of air bubbles from the internal circulation path.

[0057] In the external circulation path exhaust process of STEP 10, as in STEP 6 and STEP 8, the circulation pump 23 is operated intermittently for 10 seconds and then stopped for 10 seconds, and this is repeated three times to circulate the air bubbles in the external circulation path together with the heat transfer medium, thereby promoting the discharge of the air bubbles from the air vent 26 (and air separator 67).

[0058] In the heating and exhausting process of STEP 11, the circulation pump 23 is operated to circulate the heat medium, while combustion is performed by the burner 3 to heat the heat medium passing through the second heat exchanger 16 and the first heat exchanger 15. Even if bubbles are exhausted in the external circulation path exhausting process and the internal circulation path exhausting process as described above, air (nitrogen and oxygen) is still dissolved in the heat medium, so heating the heat medium can turn the dissolved air into bubbles and promote their exhaust. By reducing the amount of air dissolved in the heat medium in this way, bubbles are less likely to form even when the heat medium is heated in heating or hot water supply operation during actual use of the heating and hot water supply device 1, and therefore problems caused by bubbles can be suppressed.

[0059] In the illustrated example, the three-way valve 29 is switched to the simultaneous operation state, and the circulation pump 23 is continuously operated while the burner 3 is performing combustion. This simultaneously heats the heat transfer medium in both the external and internal circulation paths, efficiently reducing dissolved air. Combustion in the burner 3 continues until the temperature detected by the supply temperature sensor 25 reaches or exceeds a predetermined temperature for a certain period of time. This predetermined temperature is set to the higher of the target supply temperature for heating operation and the target supply temperature for hot water supply operation. In this way, heating the heat transfer medium to the higher temperature expected for use in the heating and hot water supply device 1 to aerate the dissolved air reduces the amount of bubbles that may form in the heat transfer medium during actual use and prevents problems caused by bubbles. Note that, in STEP 11, the circulation pump 23 may also be repeatedly operated intermittently to expel bubbles from the air vent 26.

[0060] As described above, in the heating and hot water supply device 1 of this embodiment, a trial run is performed after installation to circulate the heat medium and promote the discharge of air bubbles, and this trial run includes an external circulation path exhaust process to promote the discharge of air bubbles from the external circulation path that circulates the heat medium to the heating terminal, and an internal circulation path exhaust process to promote the discharge of air bubbles from the internal circulation path that circulates the heat medium to the hot water heat exchanger 28. In the internal circulation path exhaust process, while the circulation pump 23 is operating, the position of the three-way valve 29 is switched from a hot water operation state in which the heat medium is circulated in the internal circulation path to a heating operation state in which the heat medium is circulated in the external circulation path.

[0061] In the heating and hot water supply device 1 of this embodiment, the three-way valve 29 is in the hot water operation position while the circulation pump 23 is operating, causing bubbles remaining in the hot water heat exchanger 28 (internal circulation path) to circulate along with the heat transfer medium. If the three-way valve 29 is switched to the heating operation position before the bubbles reach the junction between the supply passage 21 and the branch passage 27 via the second heat exchanger 16 and the first heat exchanger 15 (the common portion of the external and internal circulation paths), the bubbles are guided to the heating terminal (external circulation path), thereby facilitating the discharge of bubbles from the internal circulation path. Because the external circulation path generally holds a larger amount of heat transfer medium than the internal circulation path, circulating bubbles through the external circulation path takes longer to reach the common portion, the first heat exchanger 15, and the supply temperature sensor 25, than circulating through the internal circulation path. This lengthens the period during which bubbles cause malfunctions (disturbances in the heat transfer medium temperature regulation performance). Alternatively, by moving the bubbles from the internal circulation path to the external circulation path, the bubbles disperse rather than remaining in the internal circulation path, reducing the ratio of bubbles to the amount of heat transfer medium, thereby reducing the frequency of problems caused by bubbles.

[0062] Furthermore, in the external circulation path exhaust step in the heating and hot water supply device 1 of this embodiment, the circulation pump 23 is operated while the position of the three-way valve 29 is maintained in the heating operation state, and the internal circulation path exhaust step is executed after the external circulation path exhaust step. By first executing the external circulation path exhaust step to preliminarily discharge air bubbles from the heating terminal (external circulation path), it is possible to prevent air bubbles from flowing from the heating terminal into the second heat exchanger 16 or the first heat exchanger 15 (the common part of the external circulation path and the internal circulation path) when the position of the three-way valve 29 is switched to the heating operation state in the internal circulation path exhaust step.

[0063] Additionally, in the heating and hot water supply device 1 of this embodiment, the internal circulation path exhaust process is performed multiple times with different times for which the position of the three-way valve 29 is maintained in the hot water operation state. In this way, the timing at which the position of the three-way valve 29 switches to the heating operation state changes over the multiple internal circulation path exhaust processes, so that it is possible to prevent the occurrence of a situation in which the position of the three-way valve 29 switches to the heating operation state after the air bubbles in the hot water heat exchanger 28 circulate together with the heat medium via the second heat exchanger 16 and the first heat exchanger 15 and then return to the hot water heat exchanger 28, and the position of the three-way valve 29 is repeatedly switched to the heating operation state. In addition, instead of maintaining the position of the three-way valve 29 in the hot water operation state for a certain period of time, the rotation speed of the circulation pump 23 may be changed, and as the flow rate of the circulating heat medium changes, the time required for the air bubbles in the hot water heat exchanger 28 to circulate together with the heat medium and return to the hot water heat exchanger 28 via the second heat exchanger 16 and the first heat exchanger 15 changes.Therefore, by switching the position of the three-way valve 29 to the heating operation state before the air bubbles return to the hot water heat exchanger 28, it is possible to guide the air bubbles into the external circulation path.

[0064] Furthermore, in the heating and hot water supply device 1 of this embodiment, the trial operation includes a heating and exhausting process in which the heat medium is circulated by operating the circulation pump 23 while combustion is performed by the burner 3 to heat the heat medium passing through the second heat exchanger 16 and the first heat exchanger 15. The heating and exhausting process is performed after the external circulation path exhausting process and the internal circulation path exhausting process are performed. Even when the external circulation path exhausting process and the internal circulation path exhausting process are performed, air (nitrogen and oxygen) is dissolved in the heat medium, and heating the heat medium can turn the dissolved air into bubbles and promote their discharge. This makes it difficult for bubbles to form even when the heat medium is heated during heating or hot water supply operation during actual use of the heating and hot water supply device 1, thereby suppressing the occurrence of problems caused by bubbles.

[0065] In particular, in the heating and hot water supply device 1 of this embodiment, combustion in burner 3 in the heating and exhaust process is performed until the temperature detected by supply temperature sensor 25 reaches a predetermined temperature, and this predetermined temperature is set to the higher of the target supply temperature for heating operation and the target supply temperature for hot water operation. In this way, if the heat medium is heated to the higher temperature expected in use of the heating and hot water supply device 1 to pre-aerate the dissolved air, the number of bubbles generated from the heat medium by heating during actual use will decrease, and problems caused by bubbles can be suppressed.

[0066] The heating and hot water supply device 1 of this embodiment has been described above, but the present invention is not limited to the above embodiment and can be embodied in various forms without departing from the gist of the present invention.

[0067] For example, in the internal circulation path exhaust process of the above-described embodiment, the position of the three-way valve 29 is switched from the hot water operation state to the heating operation state while the circulation pump 23 is operating. However, in the internal circulation path exhaust process, the position of the three-way valve 29 may be switched from the simultaneous operation state in which the heat medium is circulated through both the external circulation path and the internal circulation path to the heating operation state while the circulation pump 23 is operating. Even when the three-way valve 29 is in the simultaneous operation state while the circulation pump 23 is operating, if the position of the three-way valve 29 is switched to the heating operation state before the air bubbles remaining in the hot water heat exchanger 28 (internal circulation path) circulate with the heat medium and pass through the second heat exchanger 16 and the first heat exchanger 15 (common portion) and reach the connection between the outflow passage 21 and the branch passage 27, the air bubbles are guided to the heating terminal (external circulation path), thereby facilitating the discharge of the air bubbles from the internal circulation path. However, if the position of the three-way valve 29 is switched from the hot water operation state to the heating operation state while the circulation pump 23 is operating, as in the above-mentioned embodiment, the entire amount of heat medium circulating by the operation of the circulation pump 23 will flow into the hot water heat exchanger 28, making it easier to push out the air bubbles from the hot water heat exchanger 28, thereby making it possible to further reduce the air bubbles remaining in the internal circulation path.

[0068] In the above-described embodiment, the duration for which the hot water operation state is maintained by the three-way valve 29 is different in each of the internal circulation path exhaust processes of STEPs 5, 7, and 9. However, when multiple sets of switching operations from the hot water operation state to the heating operation state by the three-way valve 29 are performed in each of the internal circulation path exhaust processes of STEPs 5, 7, and 9, the duration for which the hot water operation state is maintained by the three-way valve 29 may be different for each set. Alternatively, the rotation speed of the circulation pump 23 may be different for each set.

[0069] In the heating and exhausting process of the above-described embodiment, the three-way valve 29 is set to the simultaneous operation state, so that the heat transfer medium in both the external and internal circulation paths is heated simultaneously. However, during the heating and exhausting process, only one of the heat transfer mediums in the external and internal circulation paths may be heated. For example, since the external circulation path generally holds a larger amount of heat transfer medium than the internal circulation path, prioritizing heating of the heat transfer medium in the external circulation path can effectively reduce dissolved air in the heat transfer medium. Alternatively, in the summer, when heating operation will not be used for a while, only the heat transfer medium in the internal circulation path may be heated for hot water supply operation. In addition, when only one of the heat transfer mediums in the external and internal circulation paths is heated, the predetermined temperature may be set to the target temperature for the supply temperature in heating operation if the heat transfer medium in the external circulation path is heated, and the predetermined temperature may be set to the target temperature for the supply temperature in hot water supply operation if the heat transfer medium in the internal circulation path is heated. Furthermore, even when the heat medium in both the external circulation path and the internal circulation path is heated, it is not necessarily required that they are heated simultaneously, and one of the heat mediums may be heated first, followed by the other heat medium.

[0070] Furthermore, in the heating and exhaust process of the embodiment described above, combustion in the burner 3 is performed until the temperature detected by the delivery temperature sensor 25 reaches or exceeds a predetermined temperature and continues for a certain period of time. However, the heating mode by combustion in the burner 3 is not limited to this, and for example, combustion in the burner 3 may be performed at near minimum capacity to slowly heat the heat medium and reduce the difference between the delivery temperature and return temperature of the heat medium (heat the heat medium uniformly), and combustion in the burner 3 may be terminated when the temperature detected by the delivery temperature sensor 25 reaches the predetermined temperature.

[0071] In the above-described embodiment, the heating and exhausting step (STEP 11) is executed after the external circulation path exhausting step (STEPs 4, 6, 8, 10) and the internal circulation path exhausting step (STEPs 5, 7, 9). However, the external circulation path exhausting step and the internal circulation path exhausting step may be additionally executed after the heating and exhausting step is executed, and the execution of the external circulation path exhausting step and the internal circulation path exhausting step can promote the discharge of bubbles (dissolved air bubbles) generated by heating the heat medium in the heating and exhausting step.

[0072] In the above-described embodiment, the three-way valve 29 is installed at the connection between the return passage 22 and the branch passage 27. However, the installation position of the three-way valve 29 is not limited to this, and it may be installed at the connection between the supply passage 21 and the branch passage 27.

[0073] In the above-described embodiment, after installing the heating and hot water supply device 1, the installer connects the heat medium supply pipe to the injection passage 70 and manually opens the injection valve 71 to inject the heat medium. However, the heat medium supply pipe may be connected to the outflow passage 21 and the return passage 22, and a solenoid valve may be provided to open and close the heat medium supply pipe, so that the controller 40 controls the solenoid valve to automatically inject the heat medium.

[0074] In addition, in the above-described embodiment, the air vent 26 was provided in the common part between the external circulation path and the internal circulation path as an exhaust means capable of exhausting air bubbles contained in the heat transfer medium, but the exhaust means is not limited to the air vent 26, and the circulation pump 23 provided in the common part may be provided with a function of exhausting air bubbles.

[0075] In the above-described embodiment, the first heat radiating section 63a of the baseboard heater 63 and the second heat radiating section 65a of the air handling unit 65 are connected to the heating passage 61 as a secondary circuit connected to the low-loss header 60. However, the first heat radiating section 63a of the baseboard heater 63 and the second heat radiating section 65a of the air handling unit 65 may be directly connected to the supply passage 21 and the return passage 22. [Explanation of symbols]

[0076] 1...heating and hot water heater, 2...housing, 3...burner, 4...combustion unit; 5...combustion fan; 6...junction; 7...Air supply passage, 8...Gas supply passage, 9...Zero governor, 11...spark plug, 12...flame rod, 13...check valve, 15...first heat exchanger, 16...second heat exchanger, 17...exhaust duct, 18...exhaust port, 19...air intake port, 21...outlet passage, 22... Return passage 22a... Terminal side return passage, 22b... Heat exchange side return passage, 23...circulation pump, 24...return temperature sensor, 25...supply temperature sensor, 26...air vent, 27...branch passage, 28...hot water heat exchanger, 29... Three-way valve, 30... Water supply passage, 31... Hot water outlet passage, 32...water volume sensor, 33...water volume servo, 34...supply water temperature sensor, 35...heat exchanger outlet hot water temperature sensor, 36...bypass passage, 37...Bypass servo, 38...Outlet hot water temperature sensor, 40...Controller, 41...Hot water supply remote control, 42...Heating remote control, 50...Valve chamber, 51...hot water supply side valve body, 52...heating side valve body, 53...moving shaft, 54... drive mechanism, 60... low-loss header, 61... heating passage, 61a...first heating passage, 61b...second heating passage, 62...first pump, 63...baseboard heater, 63a...first heat dissipation portion, 64...second pump, 65...air handling unit, 65a...second heat dissipation portion, 66...dirt trap, 67...air separator, 68...connecting passage, 69...expansion tank, 70...injection passage, 71...injection valve, 72...pressure sensor.

Claims

1. A heating and hot water supply device capable of performing a heating operation in which a heat medium is circulated to a heating terminal by a circulation pump for heating, and a hot water supply operation in which the shared heat medium is circulated to a hot water heat exchanger and water supplied to the hot water heat exchanger is heated by heat exchange with the heat medium, an external circulation path for circulating the heat medium to the heating terminal; an internal circulation path that includes a common portion with the external circulation path and circulates the heat medium to the hot water heat exchanger; a heating means capable of heating the heat medium in the common portion; a temperature sensor that detects the temperature of the heat medium in the common portion; a circulation switching means capable of switching among a heating operation state in which the heat medium is circulated in the external circulation path, a hot water supply operation state in which the heat medium is circulated in the internal circulation path, and a simultaneous operation state in which the heat medium is circulated in both the external circulation path and the internal circulation path; an exhaust means capable of discharging bubbles contained in the heat medium; a test operation control means for controlling the execution of a test operation that circulates the heat medium after the heat medium is injected to promote the discharge of the air bubbles; Equipped with The test operation includes an external circulation path exhaust step of facilitating the discharge of the air bubbles from the external circulation path, and an internal circulation path exhaust step of facilitating the discharge of the air bubbles from the internal circulation path, In the internal circulation path exhaust step, the circulation switching means performs an operation of switching from the hot water supply operation state or the simultaneous operation state to the heating operation state while the circulation pump is operating. A heating and hot water supply device characterized by the above.

2. The heating and hot water supply device according to claim 1, In the internal circulation path exhaust step, the circulation switching means performs an operation of switching from the hot water supply operation state to the heating operation state while the circulation pump is operating. A heating and hot water supply device characterized by the above.

3. The heating and hot water supply device according to claim 1 or 2, In the external circulation path exhaust step, the circulation pump is operated while the circulation switching means maintains the heating operation state, The test operation control means executes the internal circulation path exhaust process after the external circulation path exhaust process is executed. A heating and hot water supply device characterized by the above.

4. The heating and hot water supply device according to claim 1 or 2, The test operation control means executes the internal circulation path exhaust process a plurality of times by varying the timing of switching to the heating operation state by the circulation switching means or the flow rate at which the heat medium is circulated by the circulation pump. A heating and hot water supply device characterized by the above.

5. The heating and hot water supply device according to claim 1 or 2, the test operation includes a heating and exhausting step of circulating the heat medium heated by the heating means through at least one of the external circulation path and the internal circulation path, The test operation control means executes the heating exhaust step after executing the external circulation path exhaust step and the internal circulation path exhaust step. A heating and hot water supply device characterized by the above.

6. The heating and hot water supply device according to claim 5, In the heating and exhausting step, the heating means heats the heat medium until the temperature detected by the temperature sensor reaches a predetermined temperature, The predetermined temperature is set to the higher of the target temperature of the heat medium in the heating operation and the target temperature of the heat medium in the hot water supply operation. A heating and hot water supply device characterized by the above.

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