KR100302386B1 - Two-way pump for gas boiler, control circuit thereof, and control method thereof - Google Patents

Abstract

A control circuit and method are provided that can reduce the impact noise generated by a bidirectional pump when switching modes of a gas boiler. In the control circuit, the first and second switches switch the AC voltage selectively applied to the bidirectional pump motor as the bidirectional pump driving voltage in accordance with the gas boiler driving state. The driver selectively drives the first and second switches in accordance with the gas boiler driving state. The synchronization signal generator detects a plurality of zeros from the AC voltage for a certain cycle and generates a pulse signal at the detected zeros. The controller generates first and second control signals for controlling first and second switches, respectively, in response to the pulse signal from the synchronization signal generator, and controls the first and second switches according to the boiler driving state. And a duty cycle of the second control signal. According to the present invention, when switching from the hot water mode to the heating mode or the hot water mode to the heating mode, by adjusting the bidirectional pump driving voltage, that is, the speed of the bidirectional pump motor, the opening and closing hole suddenly moves when the ball of the bidirectional pump moves up and down inside the housing. Since it is not closed, the sudden change of the heating water flow is prevented to prevent the impact noise.

Description

Two-way pump of gas boiler, control circuit thereof, and control method thereof {TWO-WAY PUMP FOR GAS BOILER, CONTROL CIRCUIT THEREOF, AND CONTROL METHOD THEREOF}

TECHNICAL FIELD The present invention relates to a gas boiler, and more particularly, to a two-way pump of a gas boiler, a control circuit thereof, and a control method thereof, which circulate heated heating water to automatically switch heating and hot water modes.

The bi-directional pump of the gas boiler circulates the heated water in the heat exchanger to automatically switch between heating and hot water modes.

1 schematically shows a configuration of a conventional gas boiler.

As shown in FIG. 1, a conventional gas boiler includes a gas inlet pipe 102, a gas valve 104, a controller 105, a burner 106, a spark plug 107, an infrared sensor 109, and flue ( 108, exhaust fan 110, heating water circulation pipe 112, water tank 114, three-sided 116, heat exchanger 118, heating water supply pipe 120, water supplement pipe 122, direct water A supply pipe 126, a flow valve 130, and a circulation pump 132.

When the gas is supplied to the burner 106 by the opening and closing action of the gas valve 104, the ignition flame generated by the spark plug 107 ignites the gas. When ignition occurs, combustion flames due to combustion are generated in the burner 106. At this time, the infrared sensor 109 detects the temperature of the combustion flame, generates a salt voltage corresponding to the temperature of the combustion flame, and transmits the salt voltage to the controller 105 to thereby inform the controller 105 of the ignition and combustion state of the burner 106. To pass. When the gas is burned by ignition, the hot combustion gas generated at this time rises to the upper side. A heat exchanger 118 for heating the heating water is provided on the upper side of the burner 106 through which the combustion gas passes. The heating water circulates inside the heat exchanger 118. In addition, the direct water (cold water) passing through the direct water supply pipe 126 is heated in the heat exchanger 118. Therefore, the heating water and the direct water (cold water) are heated by the combustion in the burner 106.

The three-way 116 circulates the heating water in the heating mode, and is controlled to supply hot water in the hot water mode. Here, the recognition of the hot water mode is determined as the hot water use state by recognizing the number of water supplied to the flow valve 130 when supplying the hot water to use the hot water.

When the operation mode of the conventional gas boiler is the heating mode, the heating water heated in the heat exchanger 118 is discharged to the heating pipe (not shown) installed indoors through the heating supply pipe 120 and then again the heating water circulation pipe ( Return via 112). The heating water returned to the water tank 114 passes through the upper side 116 and the circulation pump 132 and flows back into the heat exchanger 118. The introduced heating water is heated again in the heat exchanger 118 and then discharged through the heating water supply pipe 120. The three-way 116 serves to control the flow path. That is, the three-way 116 is controlled to move the heating water from the water tank 114 to the heat exchanger 118 in the heating mode, and to circulate the closed circuit composed of the heat exchanger 118 in the hot water mode. Therefore, the direct water flowing into the heat exchanger 118 through the direct water supply pipe 126 is discharged after being heated to high temperature hot water by heat exchange with the heating water.

Conventional gas boilers having such a configuration and action are very complex inner pipe connection structure, the number of manufacturing labor is increased and the possibility of failure, such as leakage increases as the pipe connection is increased. In addition, the cost of materials rises by using a separate three-way.

Accordingly, the present invention is to solve such a conventional problem, the first object of the present invention is to provide a bidirectional pump that can simplify the pipe connection structure in the gas boiler.

It is a second object of the present invention to provide a control circuit capable of reducing impact noise generated in a bidirectional pump when switching a mode of a gas boiler.

It is a third object of the present invention to provide a control method capable of reducing impact noise generated in a bidirectional pump when switching a mode of a gas boiler.

In order to achieve the first object described above, the present invention is formed in the inlet for introducing the heating water from the water tank at the first end, respectively, formed in the second and third end to heat the heating water introduced through the inlet A housing having a hot water outlet and a heating water discharged to the water supply pipe and the heat exchanger;

A ball movably installed between the heating outlet and the hot water outlet in the housing to open and close the heating water outlet and the hot water outlet;

An impeller rotatably installed in the housing and selectively moving the heating water introduced through the inlet toward the heating water supply pipe and the heat exchanger according to a driving state of the boiler;

A diaphragm which is formed on the heating outlet side of the housing and has an inlet communicating with the heating water outlet, and is installed inside the housing to reduce the water hammer caused by the pressure of the heating water flowing through the inlet of the case. It provides a two-way pump of a gas boiler comprising a water hammer reduction device having a.

In order to achieve the second object, the present invention includes a first and second switch for switching the AC voltage selectively applied to the bidirectional pump motor as a bidirectional pump driving voltage according to the gas boiler driving state;

A driver for selectively driving the first and second switches according to the gas boiler driving state;

A synchronization signal generator for detecting a plurality of zero points from the AC voltage during a predetermined cycle and generating a pulse signal having a predetermined width at the detected zero point; And

In response to the pulse signal from the synchronization signal generator, first and second control signals for controlling the first and second switches are respectively generated according to the boiler driving state, and the phase of the bidirectional pump driving voltage is controlled. In order to provide a bidirectional pump control circuit for controlling the duty cycle of the first and second control signal when switching the mode of the gas boiler.

In order to achieve the third object, the present invention

(a) determining whether a stop mode, a heating mode, or a hot water mode of the gas boiler is selected;

(b) determining whether the bidirectional pump of the gas boiler is driven; And

(c) when the bidirectional pump of the gas boiler is running, stopping or driving the bidirectional pump by controlling the speed of the bidirectional pump for a predetermined time according to the mode of the gas boiler selected in step (a); It provides a bidirectional pump control method comprising a.

According to the present invention, the two-way pump of the gas boiler to simplify the pipe connection structure in the gas boiler. According to the bidirectional pump control circuit and method of the gas boiler, when switching from the hot water mode to the heating mode or the hot water mode to the heating mode, the bidirectional pump driving voltage, that is, the speed of the bidirectional pump motor, is adjusted so that the ball of the bidirectional pump moves inside the housing. When moving up and down, the opening and closing hole is not closed suddenly, so the sudden change of the heating water flow is prevented so that the impact noise is not generated.

1 is a view schematically showing a configuration of a conventional gas boiler.

2 is a view schematically showing a gas boiler employing a bidirectional pump according to the present invention.

3 shows an example of the bidirectional pump shown in FIG. 2.

4 is a circuit diagram showing the configuration of a bidirectional pump control circuit according to an embodiment of the present invention.

FIG. 5 is a timing diagram for describing an operation of the bidirectional pump control circuit illustrated in FIG. 4.

FIG. 5 (d) is a diagram showing the magnitude of power supplied to the bidirectional pump motor during forward and reverse rotation of the bidirectional pump motor illustrated in FIG. 4 with respect to time.

6 is a circuit diagram illustrating an example of a synchronization signal generator shown in FIG. 4.

FIG. 7 is a timing diagram for describing an operation of a synchronization signal generator shown in FIG. 6.

8 is a flowchart illustrating a bidirectional pump control method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

202: water tank 204: bidirectional pump

206: heating water supply pipe 208: hot water heat exchanger

210: heating water heat exchanger 302: housing

304: ball 306: impeller

308, 302: inlet 310: heating water outlet

312: hot water outlet 314: water hammer reduction device

316: case 318: diaphragm

400: bidirectional pump motor 402: first switch

404: second switch 406: driver

408: synchronization signal generator 410: controller

411,414: light triac 412,416: triac

602: full-wave rectifier 604: pulse signal generator

D11: first diode D12: second diode

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 schematically shows a gas boiler 20 employing a bidirectional pump according to the invention.

The gas boiler 20 includes a water tank 202, a bidirectional pump 204, a heating water supply pipe 206, a hot water heat exchanger 208, and a heating water heat exchanger 210. The water tank 202 temporarily stores the heating water heated by the heating water heat exchanger 210. The bidirectional pump 204 circulates the heating water heated by the heat exchanger 216 to automatically switch between heating and hot water usage. The heating water heat exchanger 210 heats the heating water. The bidirectional pump motor 400 controls the operation of the bidirectional pump 204.

3 shows an example of the bidirectional pump 204 shown in FIG. 2. The bidirectional pump 204 includes a housing 302, a ball 304, an impeller 306, and a water hammer reduction device 314. An inlet 308 is formed at the first end of the housing 302 to introduce heating water from the water tank 202. The second end of the housing 302 is formed with a heating outlet 310 for discharging the heating water introduced through the inlet 308 toward the heating water supply pipe 206. The third end of the housing 302 is formed with a hot water outlet 312 for discharging the heating water introduced through the inlet 308 toward the hot water heat exchanger 208. The ball 304 is movably installed between the heating outlet 310 and the hot water outlet 312 in the housing 302 to open and close the heating water outlet 310 and the hot water outlet 312. The material of the ball 304 may be any one such as steel ball, rubber, plastic, or Teflon, it is most preferable to use a ball made of Teflon in consideration of low absorption and durability.

An impeller 306 is rotatably installed in the housing 302 and directs the heating water introduced through the inlet 308 to the heating water supply pipe 206 and the hot water heat exchanger 208 according to the driving state of the boiler. Move it selectively.

The water hammer reduction device 314 reduces the water hammer caused by the flow of the heating water introduced through the inlet 308. The water hammer reduction device 314 includes a case 316 and a diaphragm 318. The case 316 has an inlet 320 formed at the heating water outlet 310 side of the housing 302 to communicate with the heating water outlet 310. The diaphragm 318 is installed inside the case 316 to reduce the water hammer caused by the pressure of the heating water flowing through the inlet 320 of the case 316. The diaphragm 318 separates the inside of the case 316 into the first space 322 and the second space 324.

When the user selects the heating mode, the impeller 306 of the bidirectional pump 204 rotates in the forward direction. The ball 304 is moved from the heating water outlet 310 to the hot water outlet 312 by the forward rotation of the impeller 306, and the heating water is inlet 308 of the water tank 202-the two-way pump 204. Return to the water tank 202 through the heating water outlet 310-heating water heat exchanger 208 of the two-way pump 202 to repeat the circulation. When the user selects the hot water mode, the impeller 306 of the bidirectional pump 204 rotates in the reverse direction. The reverse rotation of the impeller 306 causes the ball 304 to move from the hot water outlet 312 to the heating water outlet 310 and the heating water to the inlet 308 of the water tank 202-the two-way pump 204. -Return to the water tank 202 through the hot water outlet 312-hot water heat exchanger 208-heating water heat exchanger 210 of the two-way pump 204 to repeat the circulation. While the impeller 306 of the bidirectional pump 204 rotates in the forward or reverse direction, the diaphragm 318 of the water hammer reduction device 314 is driven by the heating water flowing in through the inlet 392 of the case 316. Under pressure, it deforms to the state indicated by the solid line. Accordingly, deformation of the diaphragm 318 reduces the water hammer due to the pressure of the heating water.

4 shows a configuration of a bidirectional pump control circuit 40 according to an embodiment of the present invention. 5 (a) to 5 (c) are timing diagrams for explaining the operation of the bidirectional pump control circuit 40 shown in FIG. Referring to FIG. 5A, the AV represents an AC voltage of 220 V generated by the AC power and applied to the bidirectional pump motor 400. Referring to FIG. 5B, CS1 and CS2 represent first and second control signals generated by the controller 410, respectively. Referring to FIG. 5C, TO1 and TO2 represent the bidirectional pump driving voltages output by the bidirectional pump control circuit 40.

The bidirectional pump control circuit 40 includes a first switch 402, a second switch 404, a driver 406, a synchronization signal generator 408, and a controller 410. The first and second switches 402 and 404 switch the AC voltage AV selectively applied to the bidirectional pump motor 400 according to the gas boiler driving state. The first switch 402 includes a first light triac 410 and a first triac 412. The first optical triac 410 is turned on / off according to the first output signal DO1 of the driver 406 to emit light. The first triac 412 is turned on / off according to the light from the first optical triac 410 and is applied to the bidirectional pump motor 400 as a bidirectional driving voltage according to the gas boiler driving state. Switch selectively. The second switch 404 includes a second light triac 414 and a second triac 416. The second light triac 414 is turned on / off in accordance with the second output signal DO2 of the driver 406 to emit light. The second triac 416 is turned on / off according to the light from the second light triac 414 and is applied to the bidirectional pump motor 400 as a bidirectional driving voltage according to the gas boiler driving state. Switch selectively. The driver 406 selectively drives the first and second switches 402 and 404 according to the boiler driving state. In the hot water mode and the heating mode, the driver 406 drives the first and second switches, respectively.

The synchronization signal generator 408 detects a plurality of zero points from the AC voltage AC 220V for a predetermined cycle and generates a pulse signal PS having a predetermined width at the detected zero point. 6 shows an example of the synchronization signal generator 408 shown in FIG. 4. The sync signal generator 408 includes a full wave rectifier 602 and a pulse signal generator 604. The full-wave rectifier 602 full-wave rectifies the AC voltage generated by the AC power AC 30V and outputs the full-wave rectified AC voltage FR. The full wave rectifier 602 includes first and second diodes D11 and D12 connected in parallel to an AC power source AC 30V. The full wave rectifier 408 includes a resistor R61 connected between the anode of the second diode D12 and ground.

The pulse signal generator 604 generates the pulse signal PS at the zero point of the full-wave rectified AC voltage from the first and second diodes D11 and D12. The pulse signal generator 604 includes an npn type transistor Q61 having an emitter terminal connected to ground, a base connected to the output terminal of the full-wave rectifier 602, and a collector connected to a power supply + 5V. The npn type transistor Q61 includes a base resistor R62 connected between the base of the npn type transistor Q61 and the output terminal of the full-wave rectifier 602. The npn type transistor Q61 includes a collector resistor R64 connected between the collector of the npn type transistor Q61 and a power supply + 5V. The npn type transistor Q61 includes a resistor R65 connected between the controller 410 and one end of the collector resistor R64 and a junction point of the collector of the npn type transistor Q61.

FIG. 7 is a timing diagram for describing an operation of the synchronization signal generator 408 shown in FIG. 6. Referring to FIG. 7A, IV denotes an input voltage of the full-wave rectifier 602 of the sync signal generator 408. Referring to FIG. 7B, FR is the full wave rectified AC voltage from the full wave rectifier 602. Referring to FIG. 7C, the PS represents a pulse signal having a predetermined width generated by the pulse signal generator 604 of the synchronization signal generator 408.

The controller 410 controls first and second switches 402 and 404, respectively, according to the boiler driving state in response to the pulse signal PS from the synchronization signal generator 408. Generate control signals CS1 and CS2. The control unit 410 controls the duty cycle of the first and second control signals CS1 and CS2 at the time of mode switching of the gas boiler to control the phase of the bidirectional pump driving voltage.

FIG. 5 (d) shows the magnitude of power supplied to the bidirectional pump motor 400 during forward and reverse rotation of the bidirectional pump motor 400 shown in FIG. 4 with respect to time. The time point t0 represents a time point at which the hot water mode is started by the reverse rotation of the pump motor 400. The first time interval T1 from the time point t0 to t1 represents the time interval for maintaining the hot water mode by continuously rotating the bidirectional pump 204. The time point t1 represents a time point at which the hot water mode is stopped. The second time interval T2 from the time point t1 to t2 is a time interval for removing the loss due to the load caused by the inertial force of the bidirectional pump motor 400 when switching from the hot water mode to the heating mode. According to an embodiment of the invention, the second time interval T2 is preferably for 2 seconds. The time point t2 represents a time point at which the heating mode is started by the forward rotation of the pump motor 400. The third time interval T3 from the time point t2 to the time point t3 causes the bidirectional pump motor 400 to rotate in a manner of increasing speed while the time is elapsed for 5 seconds, thereby gradually rotating the bidirectional pump 204 forward. to be. The fourth time interval T4 of the time t4 at the time point t3 is a time interval for maintaining the heating mode by continuously rotating the bidirectional pump 204. The time point t4 is a time point at which the heating mode starts to stop. The fifth time interval T5 of time t5 at time t4 is a time interval for gradually rotating the bidirectional pump 204 by rotating the bidirectional pump motor 400 in a manner in which the speed decreases over time.

Hereinafter, an operation of a bidirectional pump control circuit and a bidirectional pump control method according to an embodiment of the present invention will be described with reference to the accompanying drawings. 8 is a flowchart illustrating a bidirectional pump control method according to an embodiment of the present invention.

In step S101, the controller 410 determines whether the hot water mode of the gas boiler is selected. As a result of the determination in step S101, when the hot water mode of the gas boiler is selected, the controller 410 determines whether the bidirectional pump 204 is driven (step S102).

As a result of the determination in step S102, when the bidirectional pump 204 is stopped, the control unit 410 rotates the bidirectional pump 204 backward at a time point t0 or a time point t6 as shown in FIG. 5 (d) (step S103). At this time, the synchronization signal generator 408 generates a pulse signal PS having a predetermined width as shown in FIG. 7C and inputs it to the controller 410 for a predetermined cycle. In response to the pulse signal PS from the synchronization signal generator 408, the controller 410 supplies the first control signal CS1 at the high level and the second control signal CS2 at the low level, respectively. 2 Apply to input terminals DI1 and DI2. Accordingly, the driver 406 turns the first and second switches 402 and 404 respectively in response to the high level first control signal CS1 and the low level second control signal CS2 from the controller 410. -Turn off and turn on. Accordingly, referring to FIG. 5 (d), an AC voltage of 220 V is applied to the bidirectional pump motor 400 during the first time interval from the time point t0 to the time point t1 to reversely rotate the bidirectional pump 204. The processing routine then returns to step S101. On the contrary, when it is determined in step S102 that the bidirectional pump 204 is driven, the controller 410 determines whether the bidirectional pump 204 is rotating forward (step 104).

As a result of the determination in step S104, when the bidirectional pump 204 is rotating forward, the controller 410 controls the bidirectional pump in such a manner that the speed is gradually decreased during the fifth time interval T5, that is, during the elapse of time for 5 seconds. 204 is stopped at low speed and the ball 304 is moved from the hot water outlet 312 inside the housing 302 to the hot water outlet 310 (step S105). In this case, the controller 410 controls the duty cycle for a fifth time interval (5 seconds) from the time point t4 to the time point t5 as shown in FIG. 8 in response to the pulse signal PS from the synchronization signal generator 408. The first control signal CS1 is applied to the first input terminal DI1 of the driver 406. In this case, the first control signal CS1 is applied to the first input terminal DI1 of the driver 406 in such a manner that the duty cycle decreases as time passes from time t4 to time t5. At the same time, the control unit 410 applies a second high level control signal CS2 to the second input terminal of the driver 406 for 5 seconds from t4 to the time point t5. Accordingly, the driver 406 turns on the first switch 402 for 5 seconds so that an alternating-voltage alternating voltage is applied to the bidirectional pump motor 400 as shown in FIG. 7C. Accordingly, the bidirectional pump motor 400 is stopped in such a manner that the speed gradually decreases over time for 5 seconds from t4 to the time t5. Therefore, when the ball 304 of the bi-directional pump 204 moves from the hot water outlet 312 inside the housing 302 to the heating water outlet 310, the opening and closing hole is not rapidly closed, so that a sudden change in the heating water flow is prevented and impacted. Do not make noise. Thereafter, the processing routine returns to step S101.

Alternatively, when the bidirectional pump 204 is rotating in step S104, the control unit 410 continues to rotate the bidirectional pump 204 from time t0 to t1 or from t6 to t7 as shown in FIG. 5D. To maintain the hot water mode (step S106).

On the other hand, when it is determined in step S101 that the hot water mode of the gas boiler is not selected, the controller 410 determines whether the heating mode of the gas boiler is selected (step S107). As a result of the determination in step S107, when the heating mode of the gas boiler is not selected, the controller 410 determines that the stop mode of the gas boiler is selected and determines whether the bidirectional pump 204 is driven (step S108). ). As a result of the determination in step S108, when the bidirectional pump 204 is driven, the control unit 410 determines whether the bidirectional pump 204 is rotating forward (step S109).

As a result of the determination in step S109, when the bidirectional pump 204 is rotating forward, the controller 410 passes the bidirectional pump 204 for 5 seconds in the same manner as in step 105. Stop at low speed in such a way that the speed is gradually reduced during operation (step 110). Thereafter, the controller 410 terminates all operations. On the contrary, when the bidirectional pump 204 is rotating in reverse, the control unit 410 stops the bidirectional pump 204 at high speed (step S111). Thereafter, the controller 410 terminates all operations.

On the other hand, when it is determined in step S107 that the stop mode of the gas boiler is not selected, the controller 410 determines that the heating mode of the gas boiler is selected and determines whether the bidirectional pump 204 is driven. (Step S112). As a result of the determination in step S112, when the bidirectional pump 204 is stopped, the controller 410 rotates the bidirectional pump 204 forward at a low speed for 5 seconds and moves the ball 304 to the heating water outlet (inside the housing 302). In step 310, it is moved to the hot water outlet 312 (step S113).

At this time, the control unit 410 controls the duty cycle for a third time interval (5 seconds) from the time point t2 to the time point t3 as shown in FIG. 5D in response to the pulse signal PS from the synchronization signal generator 408. The first control signal CS1 is applied to the first input terminal DI1 of the driver 406. In this case, the first control signal CS1 is applied to the first input terminal DI1 of the driver 406 in such a manner that the duty cycle increases while the time passes from the time point t2 to the time point t3. At the same time, the control unit 410 applies the high level second control signal CS2 to the second input terminal of the driver 406 for 5 seconds from t2 to the time point t3. Accordingly, the driver 406 turns on the first switch 402 for 5 seconds so that an alternating-voltage alternating voltage is applied to the bidirectional pump motor 400 as shown in FIG. 7C. The bidirectional pump motor 400 rotates forward in such a manner that the speed gradually increases over time from the time point t2 to the time point t3. Therefore, when the ball 304 of the bi-directional pump 204 moves from the heating water outlet 310 inside the housing 302 to the hot water outlet 312, the opening and closing hole is not rapidly closed, so that a sudden change in the heating water flow is prevented and impacted. Do not make noise. Thereafter, the processing routine returns to step S101. On the other hand, according to an embodiment of the present invention, in order to switch from the hot water mode to the heating mode, as shown in FIG. In order to eliminate the loss caused by the inertia force, it is to be stopped for 2 seconds from the time t1 to the time t2.

On the contrary, when the bidirectional pump 204 is driven in step S112, the control unit 410 determines whether or not the bidirectional pump 204 is rotating forward (step S114). As a result of the determination in step S114, when the bidirectional pump 204 is rotating in reverse, the control unit 410 stops the bidirectional pump 204 at high speed (step S115). On the contrary, when it is determined that the bidirectional pump 204 is rotating forward, the controller 410 keeps the heating mode by continuously rotating the bidirectional pump 204 from time t3 to t4 as shown in FIG. 5D. (Step S116).

As described above, the bidirectional pump of the gas boiler according to the present invention allows to simplify the pipe connection structure in the gas boiler. According to the bidirectional pump control circuit and method of the gas boiler according to the present invention, when switching from the hot water mode to the heating mode or the hot water mode to the heating mode, the bidirectional pump driving voltage, that is, the speed of the bidirectional pump motor is adjusted. Thus, when the ball of the bidirectional pump moves up and down inside the housing, the ball closes the opening and closing holes slowly, thereby preventing a sudden change in the heating water flow, thereby preventing shock noise.

Claims (6)

An inlet formed at the first end to introduce heating water from the water tank, and a heating and hot water outlet formed at each of the second and third ends to discharge the heating water introduced through the inlet to the heating water supply pipe and the heat exchanger; A housing having a; A ball movably installed between the heating outlet and the hot water outlet in the housing to open and close the heating water outlet and the hot water outlet; An impeller rotatably installed in the housing and selectively moving the heating water introduced through the inlet toward the heating water supply pipe and the heat exchanger according to a driving state of the boiler; A case having an inlet formed on the heating outlet side of the housing and communicating with the heating outlet, and a diaphragm installed inside the case to reduce water hammer caused by the pressure of the heating water flowing through the inlet of the case. Two-way pump of a gas boiler comprising a water hammer reduction device provided. First and second switches for switching an alternating voltage selectively applied to the bidirectional pump motor as the bidirectional pump driving voltage according to the gas boiler driving state; A driver for selectively driving the first and second switches according to the gas boiler driving state; A synchronization signal generator for detecting a plurality of zero points from the AC voltage during a predetermined cycle and generating a pulse signal having a predetermined width at the detected zero point; And In response to the pulse signal from the synchronization signal generator, first and second control signals for controlling the first and second switches, respectively, are generated according to the boiler driving state, and the phase of the bidirectional pump driving voltage is generated. And a control unit for controlling the duty cycle of the first and second control signals when switching the mode of the gas boiler for controlling. The light emitting apparatus of claim 2, wherein the first and second switches each include: an optical triac, which is turned on / off in accordance with an output signal of the driver to emit light; And And a triac that is turned on / off according to the light from the optical triac and selectively switches an alternating voltage applied to the bidirectional pump motor as the bidirectional pump driving voltage according to the gas boiler driving state. Bidirectional pump control circuit. The apparatus of claim 2, wherein the synchronization signal generator comprises: a full-wave rectifier connected to an AC power source for full-wave rectifying an AC voltage generated by the AC power source; And And a pulse signal generator for generating the pulse signal at the zero point of the full-wave rectified AC voltage from the full-wave rectifier. (a) determining whether a stop mode, a heating mode, or a hot water mode of the gas boiler is selected; (b) determining whether the bidirectional pump of the gas boiler is driven; And (c) when the bidirectional pump of the gas boiler is running, stopping or driving the bidirectional pump by controlling the speed of the bidirectional pump for a predetermined time according to the mode of the gas boiler selected in step (a); Bidirectional pump control method comprising a. 6. The method of claim 5, wherein when the stop mode of the gas boiler is selected in step (a), step (c) determines whether the bidirectional pump is forward or reverse rotation, and the bidirectional pump is forward rotation. Stopping the bidirectional pump in such a way that the speed decreases as time passes for a predetermined time, and stopping the bidirectional pump at high speed when the bidirectional pump is rotating in reverse; If the heating mode of the gas boiler is selected in step (a), step (c) determines whether the bidirectional pump is rotating forward or reverse, and if the bidirectional pump is rotating forward, continues the bidirectional pump. Forward rotation and stopping the bidirectional pump at high speed when the bidirectional pump is in reverse rotation; If the hot water mode of the gas boiler is selected in step (a), step (c) determines whether the bidirectional pump is rotating forward or reverse, and if the bidirectional pump is rotating forward, the bidirectional pump is predetermined. Stopping the bidirectional pump in such a way that the speed decreases over time for a period of time, and continuously rotating the bidirectional pump when the bilateral pump is rotating in reverse.