Heat source device using proportional solenoid valve, control method, program, recording medium, control device, and hot water supply device

Abstract

To improve control characteristics in fuel control by reducing or avoiding an impact of residual magnetism on a proportional solenoid valve.SOLUTION: A heat source device includes: a burner (24) for burning a fuel gas (G); a proportional solenoid valve (78) installed in a distribution passage of the fuel gas for adjusting fuel gas to the burner; a driving part (148) for generating driving current and exciting a proportional solenoid of the proportional solenoid valve with the driving current; and a control part (150) for magnetizing a yoke and a movable magnetic pole to mutually different magnetic poles by the excitation of the proportional solenoid irrespective of a flow direction of the driving current, moving a valve body (118) of the proportional solenoid valve by the attractive force of the magnetic pole generated in the movable magnetic pole and the yoke, reversing the polarity of the driving current at a cycle faster than the movement of the valve body to generate an alternating magnetic field, and offsetting at least the residual magnetism of the movable magnetic pole.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to control technologies for a heat source device, a control method, a program, a control device, and a hot water supply device that use a proportional solenoid valve to control fuel gas, for example.

Background Art

[0002] In a heat source device used in a hot water supply device that heats water to supply hot water, a proportional valve that controls the supply amount of fuel gas according to the hot water supply demand is used. As this proportional valve, a proportional solenoid valve that controls the valve opening by exciting a proportional solenoid is known. For example, control by a PWM (pulse width modulation) method is used for the opening control of the proportional solenoid valve. Regarding the PWM control of this proportional solenoid valve, in a suspension control device, control for adjusting the period of dither vibration is known regardless of the magnitude of the energizing current (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, in a proportional solenoid valve, there is a difference between the drive current when the drive current flowing through the solenoid is increased to reach a specific valve opening degree and the drive current when the drive current is decreased to reach the specific valve opening degree. Also, there is a difference between the valve opening degree when the drive current is increased to reach a specific drive current and the valve opening degree when the drive current is decreased to reach the specific drive current. That is, there is hysteresis in the drive current and the valve opening degree. Even with the same drive current, there is a difference in the valve opening degree depending on whether it is increasing or decreasing, and even with the same valve opening degree, there is a difference in the drive current.

[0005] In a water heater using such a proportional solenoid valve for fuel control, there are problems such as a change in the combustion state, a deviation in the hot water outlet temperature, and a time required for the initial setting of fuel control on the production line. For example, a burner has two different burner parts. When the hot water supply demand is low, only one burner part is burned (single-stage combustion). When the hot water supply demand is medium, only the other burner part is burned (two-stage combustion). When the hot water supply demand increases, it is possible to select a combustion mode in which the two burner parts are burned simultaneously (three-stage combustion). When fuel control is performed with a proportional solenoid valve to cope with such an increase or decrease in hot water supply demand, there is hysteresis in each of single-stage combustion, two-stage combustion, and three-stage combustion. This hysteresis causes a difference in the valve opening degree with the same drive current, resulting in a difference in the CO value and NOx value generated during combustion, that is, there is a problem that the combustion state changes. This change in the combustion state is significant, for example, in single-stage combustion when the amount of combustion gas is small. There is a problem that the hysteresis characteristic affects the hot water outlet temperature, causing a deviation in the hot water outlet temperature with respect to the hot water supply demand. Also, there is a problem that it takes time and requires a considerable amount of time for the secondary pressure setting to reduce the influence of the hysteresis characteristic on the production line. The cause of such hysteresis lies in the magnetization characteristic of the proportional solenoid valve, especially the residual magnetism. When a magnetic material is used, the influence of this residual magnetism cannot be ignored.

[0006] Considering the magnetism and the excitation of the solenoid, there is a problem that the residual magnetism is added to the generated magnetic force when the proportional solenoid is excited in the same direction as the residual magnetism, while a part of the generated magnetic force is canceled out by the residual magnetism when the proportional solenoid is excited in the opposite direction to the residual magnetism. Regarding the problems of the proportional solenoid valve for the heat source device, the inventor has found that in order to reduce the influence of the residual magnetism, an alternating magnetic field may be generated in the proportional solenoid, and a desired valve opening degree can be obtained depending on the level of the drive current that generates such an alternating magnetic field. Therefore, in view of the above problems and findings, an object of the present disclosure is to improve the control characteristics in fuel control by reducing or avoiding the influence of residual magnetism on the proportional solenoid valve.

Means for Solving the Problems

[0007] To achieve the above object, according to one aspect of the heat source device of the present disclosure, there are provided a burner for burning fuel gas, a proportional solenoid valve installed in the flow path of the fuel gas to adjust the fuel gas to the burner, a drive unit that generates a drive current and excites the proportional solenoid of the proportional solenoid valve with the drive current, and magnetization of the yoke and the movable magnetic pole to different magnetic poles from each other by the excitation of the proportional solenoid regardless of the flow direction of the drive current, and movement of the valve body of the proportional solenoid valve by the attractive force of the magnetic poles generated in the movable magnetic pole and the yoke, and a control unit that reverses the polarity of the drive current at a period faster than the movement of the valve body to generate an alternating magnetic field and cancels at least the residual magnetism of the movable magnetic pole. , a logic circuit that generates a forward pulse including a polarity inversion unit that inverts the polarity of the drive current in the reverse direction to the forward direction, and generates a reverse pulse including a polarity inversion unit that inverts the polarity of the drive current in the forward direction to the reverse direction, and a pulse width control unit that controls the duty ratio of the forward pulse excluding the polarity inversion unit or the duty ratio of the reverse pulse excluding the polarity inversion unit It has. In this heat source device, further provided are a heat exchanger that exchanges the combustion heat of the fuel gas with a fluid to be heated, and a temperature sensor that detects the temperature of the fluid to be heated, and the control unit may change the current level of the drive current according to the detected temperature of the fluid to be heated and control the valve opening degree of the proportional solenoid valve. 。

[0008] To achieve the above object, according to one aspect of the control method of the present disclosure, there is provided a control method using a proportional solenoid valve for controlling fuel gas, the method including: a step of generating a drive current for exciting a proportional solenoid of the proportional solenoid valve; a step of burning the fuel gas that has passed through the proportional solenoid valve; magnetizing a yoke and a movable magnetic pole to different magnetic poles from each other by exciting the proportional solenoid regardless of the flow direction of the drive current, moving a valve body of the proportional solenoid valve by a magnetic attraction force of the magnetic poles generated in the movable magnetic pole and the yoke, and inverting the polarity of the drive current at a period faster than the movement of the valve body to generate an alternating magnetic field, and canceling at least residual magnetism of the movable magnetic pole. , a step of generating a forward pulse including a polarity inversion unit that inverts the polarity of the drive current in the reverse direction to the forward direction, a step of generating a reverse pulse including a polarity inversion unit that inverts the polarity of the drive current in the forward direction to the reverse direction, a step of controlling the duty ratio of the forward pulse excluding the polarity inversion unit, and a step of controlling the duty ratio of the reverse pulse excluding the polarity inversion unit The method includes the above steps. In this control method, the method may further include: a step of exchanging heat of combustion heat of the fuel gas with a fluid to be heated; detecting a temperature of the fluid to be heated, changing a current level of the drive current according to the detected temperature of the fluid to be heated, and controlling an opening degree of the proportional solenoid valve. 。

[0009] To achieve the above object, according to one aspect of the program of the present disclosure, there is provided a program realized by a computer, the program including: a function of generating control information for generating a drive current for exciting a proportional solenoid; a function of igniting a burner and burning fuel gas that has passed through a proportional solenoid valve including the proportional solenoid; magnetizing a yoke and a movable magnetic pole to different magnetic poles from each other by exciting the proportional solenoid regardless of the flow direction of the drive current, moving a valve body of the proportional solenoid valve by a magnetic attraction force of the magnetic poles generated in the movable magnetic pole and the yoke, and inverting the polarity of the drive current at a period faster than the movement of the valve body to generate an alternating magnetic field, and canceling at least residual magnetism of the movable magnetic pole. , a function of generating a forward pulse including a polarity inversion unit that inverts the polarity of the drive current in the reverse direction to the forward direction, a function of generating a reverse pulse including a polarity inversion unit that inverts the polarity of the drive current in the forward direction to the reverse direction, a function of controlling the duty ratio of the forward pulse excluding the polarity inversion unit, and a function of controlling the duty ratio of the reverse pulse excluding the polarity inversion unit The program is realized by the computer. 。 Top To achieve the above object, according to one aspect of the recording medium of the present disclosure, the recording medium stores the above program.

[0010] To achieve the above object, according to one aspect of the control device of the present disclosure, there is provided a drive unit that generates a drive current for exciting a proportional solenoid that controls a valve opening degree by excitation and supplies the drive current to the proportional solenoid; a burner that ignites and burns fuel gas that has passed through a proportional solenoid valve provided with the proportional solenoid, magnetizes a yoke and a movable magnetic pole to different magnetic poles from each other by excitation of the proportional solenoid regardless of the flow direction of the drive current, moves a valve body of the proportional solenoid valve by the magnetic attraction force of the magnetic poles generated in the movable magnetic pole and the yoke, and reverses the polarity of the drive current at a period faster than the movement of the valve body to generate an alternating magnetic field, and a control unit that cancels at least the residual magnetism of the movable magnetic pole. , a logic circuit that generates a forward pulse including a polarity inversion unit that inverts the polarity of the drive current in the reverse direction to the forward direction, and generates a reverse pulse including a polarity inversion unit that inverts the polarity of the drive current in the forward direction to the reverse direction, and a pulse width control unit that controls the duty ratio of the forward pulse excluding the polarity inversion unit or the duty ratio of the reverse pulse excluding the polarity inversion unit ru 。

[0011] To achieve the above object, according to one aspect of the water heater of the present disclosure, water is heated using any one of the heat source device, the control method, the program, the recording medium, or the control device, and hot water is supplied at a hot water supply temperature heated to a set temperature.

Advantages of the Invention

[0012] According to the present disclosure, any of the following effects can be obtained. (1) The influence of residual magnetism in the proportional solenoid valve can be reduced or avoided, the difference in valve opening degree with respect to the drive current in the increasing direction and the decreasing direction of the current level is small, and the difference in the supply amount of fuel gas with respect to the drive current can be prevented. (2) Changes in the combustion state are suppressed, and a stable combustion state can be obtained. (3) It is possible to prevent the deviation of the hot water outlet temperature in the increasing direction and the decreasing direction of the fuel gas. (4) In the manufacturing line, it becomes easy to set the secondary gas pressure after passing through the proportional solenoid valve.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

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Figure 12

Figure 13

Figure 14

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Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0014] 〔First Embodiment〕 FIG. 1 shows a water heater according to the first embodiment. The configuration shown in FIG. 1 is an example, and the present disclosure is not limited to such a configuration. This water heater 2 is an example of the heat source device of the present disclosure. This water heater 2 includes a hot water supply port 6, a water supply port 8, a fuel gas port 10, a drain port 12, and an exhaust port 14 in a housing 4. The housing 4 is installed on, for example, a wall surface of a building.

[0015] A hot water supply pipe 16 for supplying hot water HW to a required location is connected to the hot water supply port 6. A water supply pipe 18 such as a water pipe (not shown) for supplying water W is connected to the water supply port 8. A gas pipe 20 for supplying fuel gas G is connected to the fuel gas port 10. The drain port 12 is used for discharging drain D generated by heat exchange of combustion heat. The exhaust port 14 discharges the combustion exhaust after heat exchange.

[0016] A combustion chamber 22 is installed at the center of the housing 4. A burner 24, an igniter 26, a spark plug 27, a flame rod 28, an air supply fan 30, a primary heat exchanger 32, a secondary heat exchanger 34, and a drain receiver 36 are installed in this combustion chamber 22. The burner 24 includes, for example, first and second burner portions 24-1 and 24-2 having different burner surfaces, and it is possible to perform combustion of only the burner portion 24-1, combustion of only the burner portion 24-2, and simultaneous combustion of the burner portions 24-1 and 24-2. When hot water supply is required, the fuel gas G of the burner 24 is ignited by the igniter 26 and the spark plug 27, and the flame rod 28 detects the combustion of the fuel gas G of the burner 24.

[0017] The air supply fan 30 takes in combustion air into the combustion chamber 22 during the combustion of the burner 24. The primary heat exchanger 32 mainly exchanges sensible heat of the upstream combustion exhaust gas with the feed water W to heat the feed water W. The secondary heat exchanger 34 mainly exchanges latent heat of the downstream combustion exhaust gas with the feed water W to heat the feed water W. This secondary heat exchanger 34 is installed on the upstream side of the feed water W with respect to the primary heat exchanger 32 and is connected in series with the primary heat exchanger 32 by a connecting pipe 35. The drain receiver 36 receives the drain D generated by the heat exchange of the secondary heat exchanger 34 and leads to the drain tank 38. The drain D stored in this drain tank 38 reaches the drain port 12 from the drain discharge pipe 40.

[0018] The fuel gas G supplied to the fuel gas port 10 is led from the gas supply pipe 42 to the valve unit 44, and reaches the burner part 24-1 from the gas supply pipe 42-1 and the burner part 24-2 from the gas supply pipe 42-2. The valve unit 44 has an original valve function for switching the fuel gas G between the supply state and the shut-off state, a proportional valve function for adjusting the supply of the fuel gas G according to the hot water supply demand, and a switching valve function for switching the supply of the fuel gas G to the burner parts 24-1 and 24-2.

[0019] A water supply pipe 46 for supplying the feed water W to the secondary heat exchanger 34 is provided between the water supply port 8 and the secondary heat exchanger 34. A temperature sensor 48, a water volume sensor 50, and a mixed water control valve 52 are installed on this water supply pipe 46. The temperature sensor 48 detects the temperature of the feed water W. The water volume sensor 50 detects the water supply volume flowing through the water supply pipe 46. The mixed water control valve 52 controls the mixing of the hot water HW heated by the primary heat exchanger 32 and the secondary heat exchanger 34 and the feed water W.

[0020] A hot water outlet pipe 54 on the primary heat exchanger 32 side and a hot water supply pipe 56 on the hot water supply port 6 side are provided between the hot water supply port 6 and the primary heat exchanger 32. A temperature sensor 58 is installed on the hot water outlet pipe 54. A water control valve 60 is installed between this hot water outlet pipe 54 and the hot water supply pipe 56, and a bypass pipe 62 is connected between the water control valve 60 and the mixed water control valve 52. The water control valve 60 controls the hot water outlet volume of the hot water HW. A temperature sensor 64 is installed on the hot water supply pipe 56.

[0021] The detected water volume from the water volume sensor 50, the detected temperature representing the feed water temperature from the temperature sensor 48, the detected temperature representing the hot water outlet temperature from the temperature sensor 58, and the detected temperature representing the hot water supply temperature from the temperature sensor 64 are taken into the control device 66. The control device 66 acquires these detected information and controls the combustion gas volume by the valve unit 44 to realize hot water supply at the hot water supply temperature controlled to the set temperature.

[0022] FIG. 2 shows the front of the valve unit 44, FIG. 3 shows the cut end face cut along line III-III of FIG. 2, and FIG. 4 shows the cut end face cut along line IV-IV of FIG. 2. The configurations shown in FIGS. 2 to 4 are examples, and the present disclosure is not limited to such configurations.

[0023] This valve unit 44 is provided with an inlet port 68 and first and second outlet ports 70-1 and 70-2 in a valve unit housing 67. An electromagnetic valve 72 is installed on the inlet port 68 side, an electromagnetic valve 74 is installed on the outlet port 70-1 side, and an electromagnetic valve 76 is installed on the outlet port 70-2 side. A proportional solenoid valve 78 is provided between the electromagnetic valve 72 and the electromagnetic valves 74 and 76.

[0024] According to this valve unit 44, as shown in FIG. 5, if the electromagnetic valve 72 and one of the electromagnetic valves 74 are controlled to the open state, the outlet port 70-1 is selected. In this state, by controlling the valve opening degree of the proportional solenoid valve 78, the amount of fuel gas flowing out from the outlet port 70-1 is controlled.

[0025] Also, as shown in FIG. 6, if the electromagnetic valve 72 and both of the electromagnetic valves 74 and 76 are controlled to the open state, both of the outlet ports 70-1 and 70-2 are selected. In this state, by controlling the valve opening degree of the proportional solenoid valve 78, the amount of fuel gas flowing out from both of the outlet ports 70-1 and 70-2 is controlled.

[0026] <Hot water supply control> FIG. 7 shows the hot water supply control of the hot water supply device 2. The control steps of this hot water supply control include the generation of hot water supply demand (S101), the opening of the electromagnetic valves 72, 74, and 76 (S102), the ignition of the burner 24 (S103), the control of the fuel gas amount according to the water amount (S104), the control of the hot water supply temperature to the set temperature (S105), the determination of the end of the hot water supply demand (S106), the closing of the electromagnetic valves 72, 74, and 76 (S107), the extinguishing of the burner 24 (S108), and the like.

[0027] Generation of hot water supply demand (S101): The hot water supply demand occurs, for example, when the hot water supply valve is opened, etc., and is connected to the hot water supply pipe 16. This hot water supply demand promotes the supply water W from the water supply pipe 18. This supply water W is detected by the water amount sensor 50, and the detection output of this water amount sensor 50 is taken into the control device 66.

[0028] Opening of the electromagnetic valves 72, 74, and 76 (S102): Triggered by the generation of the hot water supply demand, the control device 66 opens the electromagnetic valves 72, 74, and 76. As a result, the fuel gas G flows to the burner 24. Ignition of the burner 24 (S103): Triggered by the generation of the hot water supply demand, the control device 66 activates the igniter 26, and the burner 24 is ignited by the spark plug 27.

[0029] Control of the fuel gas amount according to the water amount (S104): The detected water amount of the water amount sensor 50 and the detection signals of the temperature sensors 48, etc. are taken into the control device 66 as control signals for the fuel gas amount. The control device 66 controls the opening degree of the proportional solenoid valve 78 of the valve unit 44. Control of the hot water supply temperature to the set temperature (S105): The control device 66 can set the desired hot water supply temperature by initial setting or by the user. Receiving the detected temperatures of the temperature sensors 48, 58, and 64 and the detected water amount of the water amount sensor 50, the control device 66 controls the hot water supply temperature to the set temperature and supplies hot water.

[0030] Determination of the end of the hot water supply demand (S106): The hot water supply amount is detected by the water amount sensor 50, and the control device 66 determines the end of the hot water supply demand based on the detected water amount of the water amount sensor 50. Closing of electromagnetic valves 72, 74, 76 (S107): When the hot water demand ends, the control device 66 closes the electromagnetic valves 72, 74, 76. Accordingly, the supply of fuel gas G to the burner 24 is stopped. Extinguishing of burner 24 (S108): When the supply of fuel gas G to the burner 24 stops, the burner 24 is extinguished.

[0031] Figure 8 shows the control system 102 of the valve unit 44. In Figure 8, the same parts as those in Figures 2 to 6 are denoted by the same reference numerals. In this control system 102, the proportional solenoid valve 78 is used for proportional control of the fuel gas G introduced into the passage 108. An inlet port 112-1 and an outlet port 112-2 are formed in the valve chamber 110. The passage 108 is formed between the electromagnetic valve 72 and the electromagnetic valves 74, 76 (Figure 4). The fuel gas G flowing into this passage 108 is guided from the inlet port 112-1 into the valve chamber 110, and flows from the valve chamber 110 through the valve mechanism 114 and out of the outlet port 112-2 into the passage 108.

[0032] The valve mechanism 114 includes a valve seat 116 and a valve body 118. The valve seat 116 is fixed to the wall surface of the valve chamber 110, and the valve body 118 moves in a direction orthogonal to the valve seat surface of the valve seat 116. A diaphragm 124 is attached to a shaft portion 120 formed on the central axis of the valve body 118 by a support member 122. The outer edge of the diaphragm 124 is supported between the inner walls of the valve chamber 110. Accordingly, the valve body 118 is supported by the diaphragm 124 so as to be vertically movable in the valve chamber 110. When the pressure of the fuel gas G acts in the valve chamber 110, the valve body 118 is pulled down by the bulging of the diaphragm 124.

[0033] A movable magnetic pole 126 is installed with respect to the valve body 118, and the movable magnetic pole 126 is in contact with the shaft portion 120 of the valve body 118. That is, the movable magnetic pole 126 constitutes a plunger. This movable magnetic pole 126 is inserted into the proportional solenoid 128 and is movable in the central axis direction of the valve body 118. A yoke 132 is installed in the proportional solenoid 128 with a coil 130 interposed therebetween. The coil 130 is wound around a coil bobbin 134 and installed in the proportional solenoid 128. Therefore, the yoke 132 constitutes a fixed magnetic pole with respect to the movable magnetic pole 126.

[0034] A support frame 136 is fixed to the yoke 132 side, and a space portion 138 that allows the bulge of the diaphragm 124 is formed in this support frame 136. A support member 140 is fixed to the yoke 132, and this support member 140 includes a spring support portion 142. A spring insertion portion 144 is formed in the movable magnetic pole 126, and a coil-shaped spring 146 is installed between this spring insertion portion 144 and the spring support portion 142. Therefore, the restoring force of the spring 146 acts on the movable magnetic pole 126.

[0035] The control device 66 includes, for example, a drive unit 148 and a control unit 150, and performs generation, polarity inversion, and level control of the drive current id. The drive unit 148 generates the drive current id under the control of the control unit 150 and passes this drive current id through the proportional solenoid 128. The control unit 150 includes, for example, a computer, receives the detection outputs of various sensors such as a temperature sensor and a water volume sensor as a control signal Sin, and performs information processing for controlling the proportional solenoid valve 78. This information processing includes (a) Control for generating the drive current id (b) Polarity inversion of the drive current id at a period faster than the movement of the valve body 118 (c) Control of the valve opening degree according to the current level of the drive current id and the like.

[0036] <Valve mechanism 114> Fig. 9 shows an enlarged view of the valve mechanism 114 of the proportional solenoid valve 78. The valve seat 116 is fixed to the valve chamber 110 by a holding frame 151, and the space between the valve seat 116 and the inner wall surface of the valve chamber 110 is sealed by an O-ring 152. The valve body 118 is provided with a conical surface portion 154, and the valve function is achieved by the conical surface portion 154 and the valve port portion 156 of the valve seat 116.

[0037] In the valve chamber 110, a circular concave portion 158, for example, is formed on the central axis of the valve body 118 opposite to the valve body 118. Opposite to this concave portion 158, a convex portion 160 is formed on the large-diameter surface portion of the valve body 118. When the valve body 118 moves, the convex portion 160 enters the concave portion 158 on the valve chamber 110 side, allowing the movement of the valve body 118.

[0038] <Generation of the attracting force F by the valve drive mechanism 162> Fig. 10 shows the valve drive mechanism 162 of the proportional solenoid valve 78. The valve drive mechanism 162 drives the valve body 118 in the vertical direction by exciting a drive current id. When a drive current id flows through the proportional solenoid 128, a magnetic field φ is generated in the proportional solenoid 128. As a result, the movable magnetic pole 126 and the yoke 132 (fixed magnetic pole) are magnetized, and different magnetic poles N and S are generated in the movable magnetic pole 126 and the yoke 132. The movable magnetic pole 126 moves in the direction of the attracting force F due to the attracting force F generated by the magnetic poles N-S. Regardless of the direction of the drive current id, different magnetic poles N and S are generated in the movable magnetic pole 126 and the yoke 132, so the attracting force F due to the magnetic poles N-S acts.

[0039] <Polarity inversion of the drive current id> When the polarity of the drive current id is inverted at a constant period, the polarities of the magnetic poles N and S of the movable magnetic pole 126 and the yoke 132 are inverted, but an attracting force F in the same direction acts between the two. As a result, regardless of the polarity, a valve opening degree corresponding to the current level of the drive current id can be obtained. Due to the inversion of the drive current id, the magnetization direction of the movable magnetic pole 126 and the yoke 132 is inverted, so the residual magnetism is canceled by the inversion current, and the influence of the residual magnetism can be eliminated.

[0040] <Control of Proportional Solenoid Valve 78> FIG. 11 shows an example of the control of the proportional solenoid valve 78. This control includes generation of drive current id (S201), polarity inversion of drive current id (S202), current level control of drive current id (S203), etc. Generation of drive current id (S201): The control device 66 generates the drive current id to flow through the proportional solenoid 128.

[0041] Polarity inversion of drive current id (S202): The control device 66 inverses the polarity of the drive current id at a period faster than the moving speed of the valve body 118. The movement of the valve body 118 depends on the variation of the current level of the drive current id, and the polarity inversion of the drive current id is performed at a period faster than the movement speed of the valve body 118, for example, at a period of 1 / 2 of the dither period Td. Current level control of drive current id (S203): The control device 66 controls the current level of the drive current id and controls the valve mechanism 114 to a valve opening degree corresponding to the current level.

[0042] FIG. 12 shows an example of the polarity inversion and level control of the drive current id in this control process. This control process includes input of control signal Sin (S301), calculation of duty ratio of forward pulse (S302), calculation of duty ratio of reverse pulse (S303), generation of forward pulse (execution of pulse control according to the calculated duty ratio) (S304), generation of reverse pulse (execution of pulse control according to the calculated duty ratio) (S305), control of valve opening degree (S306), etc. Input of control signal Sin (S301): The control device 66 receives the control signal Sin for controlling the valve opening degree of the valve mechanism 114. The valve opening degree is controlled by the signal level of this control signal Sin.

[0043] Calculation of duty ratio of forward pulse (S302): The control device 66 calculates the duty ratio of the forward pulse excluding the polarity control pulse Psw1 (polarity inversion part) described later. Calculation of the duty ratio of the reverse pulse (S303): The control device 66 calculates the duty ratio of the reverse pulse excluding the polarity control pulse Psw2 (polarity inversion section) described later.

[0044] Generation of the forward pulse (execution of pulse control according to the calculated duty ratio) (S304): The control device 66 generates a forward pulse for generating a forward drive current id flowing through the proportional solenoid 128. This forward pulse includes, at the head, a polarity control pulse Psw1 for reversing the current direction of the drive current id faster than the movement of the valve body 118 as a polarity inversion section. This polarity control pulse Psw1 has a larger pulse width than other forward pulses and is a high-duty ratio pulse. The polarity inversion section in the forward pulse is used to switch the polarity of the reverse drive current id to the forward drive current id.

[0045] Generation of the reverse pulse (execution of pulse control according to the calculated duty ratio) (S305): The control device 66 generates a reverse pulse for generating a reverse drive current id flowing through the proportional solenoid 128. This reverse pulse includes, at the head, a polarity control pulse Psw2 for reversing the current direction of the drive current id faster than the movement of the valve body 118 as a polarity inversion section. This polarity control pulse Psw2 has a larger pulse width than other reverse pulses and is a high-duty ratio pulse. The polarity inversion section in the reverse pulse is used to switch the polarity of the forward drive current id to the reverse drive current id. Control of the valve opening degree (S306): The control device 66 controls the current level of the drive current id according to the signal level of the control signal Sin to control the valve opening degree.

[0046] <Polarity inversion of the drive current id, its level control, and the suction force F> A in Fig. 13 shows a forward PWM pulse which is an example of a forward pulse. This forward pulse is generated during a period of 1 / 2(=Td / 2) of the dither period Td, and includes a polarity control pulse Psw1 as a polarity inversion part at the head. The polarity control pulse Psw1 has a constant pulse width in order to shorten the polarity inversion period for switching the reverse drive current id to the forward direction. On the other hand, the duty ratio of the forward PWM pulse excluding the polarity control pulse Psw1 is controlled by the control signal Sin. In A of Fig. 13, for convenience of explanation, a constant duty ratio is used, but it is controlled to different duty ratios according to the valve opening degree.

[0047] B in Fig. 13 shows a reverse PWM pulse which is an example of a reverse pulse. This reverse pulse is generated during a period of 1 / 2(=Td / 2) of the dither period Td, and includes a polarity control pulse Psw2 as a polarity inversion part at the head. The polarity control pulse Psw2 has a constant pulse width in order to shorten the polarity inversion period for switching the forward drive current id to the reverse direction. In this embodiment, the polarity control pulses Psw1 and Psw2 have the same pulse width. On the other hand, the duty ratio of the reverse PWM pulse excluding the polarity control pulse Psw2 is controlled by the control signal Sin. In B of Fig. 13, for convenience of explanation, a constant duty ratio is used, but it is controlled to different duty ratios according to the valve opening degree.

[0048] C in Fig. 13 shows the drive current id flowing in the forward or reverse direction. The drive current id is repeatedly switched from the reverse drive current id to the forward drive current id, and further from the forward drive current id to the reverse drive current id by alternately generating the polarity control pulse Psw1 and the polarity control pulse Psw2 every half period of the dither period Td. The drive current id accompanied by this polarity inversion depends on the duty ratio of the forward PWM pulse or the reverse PWM pulse, and its current level is controlled.

[0049] In FIG. 13, D shows the attractive force F acting on the movable magnetic pole 126 and the yoke 132 (fixed magnetic pole). The proportional solenoid 128 is excited by a drive current id with polarity inversion and level control, and the movable magnetic pole 126 and the yoke 132 are magnetized. Although it reverses to different magnetic pole pairs every half period of the dither period Td, the attractive force F generated between the movable magnetic pole 126 and the yoke 132 depends on the level of the drive current id.

[0050] <Effect of the First Embodiment> According to the first embodiment, any of the following effects can be obtained. (1) Since the polarity of the drive current id is reversed at a half period (=Td / 2) of the dither period Td to reverse the magnetic poles between the movable magnetic pole 126 and the yoke 132 by the proportional solenoid 128, residual magnetism can be canceled out. Since this polarity inversion is performed at a period faster than the opening and closing of the valve mechanism 114, it does not affect the control of the valve opening degree. (2) During the time interval of the polarity inversion, since the drive current id controls the current level by the duty ratio of the forward PWM pulse or the reverse PWM pulse, the valve opening degree of the valve mechanism 114 can be controlled by the current level of the drive current id without being affected by the polarity inversion of the drive current id.

[0051] 〔Second Embodiment〕 FIG. 14 shows a control system 102 for a proportional solenoid valve 78 according to the second embodiment. In the configuration of FIG. 14, the same parts as those in FIG. 8 are denoted by the same reference numerals. The drive unit 148 includes a power supply 164, a drive bridge circuit 166, a forward drive circuit 168-1, and a reverse drive circuit 168-2. The power supply 164 constitutes a current source for the drive current id. The drive bridge circuit 166 includes Pch-FETs (P-channel - field effect transistors) 171, 172, Nch-FETs (N-channel - field effect transistors) 173, 174.

[0052] The forward drive circuit 168-1 receives a forward PWM pulse from the control unit 150 and passes a forward drive current id through the proportional solenoid 128 from the drive bridge circuit 166. In contrast, the reverse drive circuit 168-2 receives a reverse PWM pulse from the control unit 150 and passes a reverse drive current id through the proportional solenoid 128 from the drive bridge circuit 166. That is, a forward drive current id flows through the proportional solenoid 128 due to the conduction of the Pch-FET 172 and the Nch-FET 173 in the first half cycle (=Td / 2) of the dither period Td, and a reverse drive current id flows through the proportional solenoid 128 due to the conduction of the Pch-FET 171 and the Nch-FET 174 in the next half cycle (=Td / 2) of the dither period Td.

[0053] The control unit 150 includes a control circuit 176, a pulse generation unit 178, a PWM generation unit 180, and a logic circuit 182. The control circuit 176 is composed of a microcomputer and includes a processor 184, a storage unit 186, and an input / output unit (I / O) 188. The processor 184 executes a control program stored in the storage unit 186 and performs control such as pulse width control according to the control signal Sin. Such control and control information include a) Control information for generating the drive current id b) Control information for reversing the polarity of the drive current id at a period faster than the movement of the valve body 118 c) Control information for controlling the valve opening degree according to the current level of the drive current id d) Calculation of the duty ratio of the forward pulse excluding the polarity control pulse e) Calculation of the duty ratio of the reverse pulse excluding the polarity control pulse f) Generation of a forward pulse including a control pulse for switching the polarity of the reverse drive current id to the forward direction (execution of the calculated pulse control) g) Generation of a reverse pulse including a control pulse for switching the polarity of the forward drive current id to the reverse direction (execution of the calculated pulse control) are included.

[0054] The memory unit 186 is an example of a recording medium that stores the program of the present disclosure. In this memory unit 186, memory elements such as ROM (Read-Only Memory), RAM (Random-Access Memory), and EEPROM (Electrically Erasable Programmable Read-Only Memory) are used and are used for the generation and storage of various control information. I / O 188 takes in the control signal Sin and generates control information. The pulse generation unit 178 generates a clock pulse with a fixed period and generates a pulse with a fixed period by dividing or multiplying the frequency of this clock pulse.

[0055] The PWM generation unit 180 has a forward PWM pulse generation function and a reverse PWM pulse generation function, generates a forward PWM pulse or a reverse PWM pulse having a duty ratio corresponding to the signal level of the control signal Sin, and outputs it to the logic circuit 182. The logic circuit 182 receives a control pulse synchronized with a period that is half of the dither period Td from the pulse generation unit 178, and outputs a forward PWM pulse and a reverse PWM pulse synchronized with Td / 2. The forward PWM pulse is provided to the forward drive circuit 168-1, and the reverse PWM pulse is provided to the reverse drive circuit 168-2.

[0056] <Effects of the Second Embodiment> According to the second embodiment, any of the following effects can be obtained. (1) Since the polarity of the drive current id is inverted at a period that is half of the dither period Td (=Td / 2) to invert the magnetic pole between the movable magnetic pole 126 and the yoke 132 by the proportional solenoid 128, residual magnetism can be canceled out and the hysteresis characteristics can be improved. (2) During the time interval of the polarity inversion, the drive current id can control the current level according to the duty ratio of the forward PWM pulse or the reverse PWM pulse, and without being affected by the polarity inversion of the drive current id, the controllability of the valve opening degree of the valve mechanism 114 can be enhanced by the current level of the drive current id.

[0057] (3) Since the influence of residual magnetism in the proportional solenoid valve 78 can be reduced or avoided, the difference in valve opening degree with respect to the drive current id in the increasing direction and the decreasing direction of the fuel gas G is small, and the difference in the increase and decrease of the fuel gas G can be prevented. (4) Changes in the combustion state are suppressed, and the combustion state can be stabilized. (5) The controllability of the hot water supply control is enhanced, and the deviation in the hot water outlet temperature in the increasing direction and the decreasing direction of the fuel gas G can be prevented. (6) In the production line, the setting of the secondary gas pressure after passing through the proportional solenoid valve becomes easy, and the production efficiency of the hot water supply device 2 can be increased.

[0058] [Third Embodiment] FIG. 15 shows a valve unit 44 and a control system 200 according to the third embodiment. In the configuration of FIG. 15, the same parts as those in FIGS. 8 and 14 are denoted by the same reference numerals. In the second embodiment (FIG. 14), the control device 66 includes a drive unit 148 and a control unit 150. On the other hand, in the control system 200 of the third embodiment, the drive unit 148 and the control unit 150 are installed inside the valve unit housing 67 together with the proportional solenoid valve 78. And a control device 66 is provided outside this valve unit 44.

[0059] The control device 66 is composed of, for example, a computer and includes a processor 202, a storage unit 204, and an I / O 206. The processor 202 executes a hot water supply control program and the like stored in the storage unit 204. This information processing includes control of the hot water supply temperature and the like using detection information from a water volume sensor 50, temperature sensors 48, 58, 64, and the like. In this control device 66, the processor 202 may share the processor 184 described above, the storage unit 204 may share the storage unit 186 described above, and the I / O 206 may share the I / O 188.

[0060] [Effects of the Third Embodiment] According to the third embodiment, any of the following effects can be obtained. (1) The same effects as those of the first embodiment or the second embodiment can be obtained. (2) The control function of the proportional solenoid valve 78 can be integrated into the valve unit 44, enabling the control device 66 to be made more compact and facilitating maintenance.

[0061] 〔Experimental Results〕 FIG. 16 shows the output characteristics of the proportional solenoid valve 78 driven by a drive current id without polarity switching, with time on the horizontal axis and the gas secondary pressure of the proportional solenoid valve 78 on the vertical axis. When the proportional solenoid 128 is excited with a drive current id without polarity reversal, since it is excited with a unidirectional drive current id, the influence of residual magnetism cannot be eliminated. That is, for a drive current id in the same direction as the residual magnetism, magnetization is enhanced, while for a drive current id in the opposite direction to the residual magnetism, the magnetization by the drive current id is impaired due to the cancellation of the residual magnetism. As a result, the influence of the hysteresis h between the control signal Sin and the gas secondary pressure according to the valve opening degree becomes prominent.

[0062] Similarly, FIG. 17 shows the output characteristics of the proportional solenoid valve 78 driven by a drive current id with polarity switching, with time on the horizontal axis and the gas secondary pressure of the proportional solenoid valve 78 on the vertical axis. When the proportional solenoid 128 is excited with a drive current id with polarity reversal, the residual magnetism is canceled by the polarity reversal with the drive current id, and the relationship between the drive current id without the influence of residual magnetism and the gas secondary pressure according to the valve opening degree is obtained. As a result, the influence of the hysteresis h between the control signal Sin and the valve opening degree is improved to an ignorable extent.

[0063] 〔Other Embodiments〕 (1) In the above embodiment, PWM control is exemplified, but control other than PWM control may be used for the control of the proportional solenoid valve 78. (2) Although the reversal period of the drive current id is set to half of the dither period Td, it only needs to be faster than the moving speed of the valve body 118 and is not limited to the period of the embodiment. (3) In the above-described embodiment, a polarity control pulse is exemplified for the polarity inversion part included in the forward pulse or the reverse pulse. However, as this polarity control pulse, in addition to the pulse generated by PWM control, a polarity inversion pulse generated separately from PWM control may be used. This polarity inversion pulse may have a period including an optimal polarity inversion timing for the polarity inversion of the drive current id, and a pulse width set to an optimal time width. (4) In the first embodiment, a hot water supply device is exemplified as an example of the heat source device. However, instead of this hot water supply device, a supplementary hot water supply device, a heating hot water supply device, or the like may be used.

[0064] As described above, the most preferred embodiments of the configuration of the present invention have been described. The present invention is not limited to the above description, and various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the form for carrying out the invention. Needless to say, such modifications and changes are included in the scope of the present invention.

Industrial Applicability

[0065] According to the present invention, the magnetic pole relationship between the movable magnetic pole and the fixed magnetic pole (yoke) can be inverted by the drive current to cancel the residual magnetism, and the valve mechanism can be driven by the magnetic force not affected by the residual magnetism, so that the hysteresis characteristics of the proportional solenoid valve can be improved. Therefore, the controllability such as fuel control and hot water supply control in a heat source device using a proportional solenoid valve can be improved.

Explanation of Signs

[0066] G Fuel gas 2 Hot water supply device 4 Housing 6 Hot water supply port 8 Water supply port 10 Fuel gas port 12 Drain port 14 Exhaust port 16 Hot water supply pipe 18 Water supply pipe 20 Gas pipe 22 Combustion chamber 24 burners Burner parts 24-1, 24-2 26 igniters 27 spark plugs 28 frame rods 30 air supply fans 32 primary heat exchangers 34 secondary heat exchangers 35 connecting pipes 36 drain receivers 38 drain tanks 40 drain discharge pipes 42 gas supply pipes Gas supply pipes 42-1, 42-2 44 valve units 46 water supply pipes 48 temperature sensors 50 water volume sensors 52 mixed water control valves 54 hot water outlet pipes 56 hot water supply pipes 58 temperature sensors 60 water control valves 62 bypass pipes 64 temperature sensors 66 control devices 67 valve unit housings 68 inlet ports Outlet ports 70-1, 70-2 72 electromagnetic valves Electromagnetic valves 74, 76 78 proportional solenoid valves Control systems 102, 200 108 passages 110 valve chambers Inlet port 112-1 Outlet port 112-2 114 valve mechanisms 116 valve seats 118 valve bodies 120 shaft parts 122 support members 124 diaphragms 126 movable magnetic poles 128 proportional solenoids 130 coils 132 Yoke 134 Coil Bobbin 136 Support Frame 138 Space Portion 140 Support Member 142 Spring Support Portion 144 Spring Insertion Portion 146 Spring 148 Driving Portion 150 Control Portion 151 Holding Frame 152 O-ring 154 Conical Face Portion 156 Valve Portion 158 Recess 160 Protrusion 162 Valve Driving Mechanism 164 Power Supply 166 Driving Bridge Circuit 168-1 Forward Driving Circuit 168-2 Reverse Driving Circuit 171, 172 Pch-FET 173, 174 Nch-FET 176 Control Circuit 178 Pulse Generation Portion 180 PWM Generation Portion 182 Logic Circuit 184, 202 Processor 186, 204 Memory Portion 188, 206 Input / Output Portion (I / O)

Claims

1. A burner for burning fuel gas; a proportional solenoid valve disposed in a flow passage of the fuel gas to adjust the fuel gas to the burner; a drive unit that generates a drive current and excites a proportional solenoid of the proportional solenoid valve with the drive current; a control unit which magnetizes the yoke and the movable magnetic pole to different magnetic poles by excitation of the proportional solenoid regardless of the flow direction of the drive current, moves a valve body of the proportional solenoid valve by an attractive force between the movable magnetic pole and the yoke, and generates an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the valve body, thereby canceling out at least the residual magnetism of the movable magnetic pole; The control unit includes: a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the driving current in the reverse direction to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the driving current in the forward direction to a reverse direction; a pulse width control section that controls a duty ratio of the forward pulse excluding a polarity reversal section, or a duty ratio of the reverse pulse excluding a polarity reversal section; A heat source device comprising:

2. a heat exchanger that exchanges heat of combustion of the fuel gas with a fluid to be heated; A temperature sensor for detecting a temperature of the heated fluid; 2. The heat source device according to claim 1, wherein the control unit receives a detected temperature of the heated fluid, changes a current level of the drive current in response to the detected temperature, and controls a valve opening degree of the proportional solenoid valve.

3. A control method using a proportional solenoid valve to control fuel gas, comprising: generating a drive current for energizing a proportional solenoid of the proportional solenoid valve; combusting the fuel gas that has passed through the proportional solenoid valve; a step of magnetizing the yoke and the movable magnetic pole to different magnetic poles by excitation of the proportional solenoid regardless of the flow direction of the drive current, moving a valve body of the proportional solenoid valve by an attractive force between the movable magnetic pole and the yoke, and reversing the polarity of the drive current at a period faster than the movement of the valve body to generate an alternating magnetic field, thereby canceling out at least the residual magnetism of the movable magnetic pole; generating a forward pulse including a polarity reversal portion that reverses the polarity of the driving current in a reverse direction to a forward direction; generating a reverse pulse including a polarity reversal portion that reverses the polarity of the forward driving current to a reverse direction; controlling a duty ratio of the forward pulse excluding a polarity reversal portion; controlling a duty ratio of the reverse pulse excluding the polarity reversal portion; A control method comprising:

4. exchanging heat of combustion of the fuel gas with a heated fluid; detecting a temperature of the heated fluid, and changing a current level of the drive current in response to the detected temperature of the heated fluid to control a valve opening degree of the proportional solenoid valve; The control method according to claim 3, comprising:

5. A program implemented by a computer, A function of generating control information for generating a drive current for exciting the proportional solenoid; A function of igniting a burner and burning fuel gas that has passed through a proportional solenoid valve equipped with the proportional solenoid; a function of magnetizing the yoke and the movable magnetic pole to different magnetic poles by excitation of the proportional solenoid regardless of the flow direction of the drive current, moving the valve element of the proportional solenoid valve by the magnetic attraction force generated between the movable magnetic pole and the yoke, and reversing the polarity of the drive current at a period faster than the movement of the valve element to generate an alternating magnetic field, thereby offsetting at least the residual magnetism of the movable magnetic pole; A function of generating a forward pulse including a polarity reversal portion that reverses the polarity of the driving current in the reverse direction to a forward direction; A function of generating a reverse direction pulse including a polarity reversal portion that reverses the polarity of the forward driving current to a reverse direction; A function of controlling the duty ratio of the forward pulse excluding the polarity reversal portion; A function of controlling the duty ratio of the reverse pulse excluding the polarity reversal portion; A program for realizing the above by the computer.

6. A recording medium storing the program according to claim 5.

7. a drive unit that generates a drive current for exciting a proportional solenoid that controls a valve opening degree by excitation, and passes the drive current through the proportional solenoid; a control unit that ignites a burner, burns fuel gas that has passed through a proportional solenoid valve equipped with the proportional solenoid, magnetizes a yoke and a movable magnetic pole to different magnetic poles by exciting the proportional solenoid regardless of the flow direction of the drive current, moves a valve body of the proportional solenoid valve by an attractive force between the movable magnetic pole and the yoke, and reverses the polarity of the drive current at a period faster than the movement of the valve body to generate an alternating magnetic field, thereby offsetting at least the residual magnetism of the movable magnetic pole; The control unit includes: a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the driving current in the reverse direction to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the driving current in the forward direction to a reverse direction; a pulse width control section that controls a duty ratio of the forward pulse excluding a polarity reversal section, or a duty ratio of the reverse pulse excluding a polarity reversal section; A control device comprising:

8. A hot water supply device comprising a heat source device as described in claim 1 or claim 2, a control method as described in claim 3 or claim 4, a program as described in claim 5, a recording medium as described in claim 6, or a control device as described in claim 7, for heating water and supplying hot water at a hot water supply temperature heated to a set temperature.

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