BOILER SYSTEM FOR BOTH HEATING AND HOT WATER

Abstract

The objective of the present invention is to provide a boiler system for bath heating and hot water that is capable of performing heating and hot water preheating by using a single circulation pump for both without the need to separately include a circulation pump for heating and a circulation pump for hot water preheating. In order to achieve the above objective, the present invention provides a boiler system for both heating and hot water, comprising: a heat exchanging unit; a heating water channel connected between the heat exchanging unit and a place to be heated; a tap water supply pipe for supplying tap water to the heat exchanging unit; a hot water supply pipe for supplying hot water to a place requiring hot water from the heat exchanging unit; a hot water recirculation channel connected to the hot water supply pipe at a first branch point branched from one side of the heating water channel; a hot water bypass channel connected from the second branch point branched from the other side of the heating water channel to the tap water supply pipe; and a circulation pump disposed between the first branch point and the second branch point.

Claims

1. A boiler system for both heating and hot water, comprising: a heat exchange unit; a heating water channel connected between the heat exchange unit and a heating destination; a tap water supply pipe through which tap water is supplied to the heat exchange unit; a hot water supply pipe through which heating is supplied from the heat exchange unit to a hot water destination; a hot water recirculation channel connected to the hot water supply pipe from a first branch point at which the hot water recirculation channel is branched from one side of the heating water channel; a hot water bypass channel connected to the tap water supply pipe at a second branch point at which the hot water bypass channel is branched from the other side of the heating water channel; and a circulation pump disposed between the first branch point and the second branch point.

2. The boiler system of claim 1, wherein the heat exchange unit includes a hot water storage type heat exchanger configured to store the heating water supplied to the heating destination therein and heat the heating water using a heat source.

3. The boiler system of claim 1, wherein the heat exchange unit includes a main heat exchanger configured to heat the heating water supplied for heating or supplied for exchanging heat by using combustion heat and a hot water heat exchanger configured to generate the hot water through a heat exchange between the heating water heated in the main heat exchanger and tap water.

4. The boiler system of claim 3, wherein the heating water channel is connected between the main heat exchanger and the heating destination, and the tap water supply pipe and the hot water supply pipe are connected to the hot water heat exchanger.

5. The boiler system of claim 1, wherein a first three-way valve is provided at the first branch point, and a second three-way valve is provided at the second branch point.

6. The boiler system of claim 1, wherein a first three-way valve is provided at the first branch point, and a check valve is provided in the hot water bypass channel to restrict a flow path such that preheated hot water flows in only one direction toward the tap water supply pipe.

7. The boiler system of claim 1, wherein the heating water channel between the first branch point and the second branch point is used as a common channel through which the heating water and preheated hot water selectively flow.

8. The boiler system of claim 1, wherein, when a hot water preheating function is selected in a room controller, the circulation pump is operated for a certain time so that the hot water preheating function is operated.

9. The boiler system of claim 8, wherein, when a hot water function is selected in the room controller during the operation of the hot water preheating function, the circulation pump is additionally operated for the certain time so that the hot water preheating function is operated.

10. The boiler system of claim 9, wherein, when hot water is used in the hot water destination during the operation of the hot water preheating function, the operation of the circulation pump is stopped, and the hot water supply function is operated.

Description

DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a view illustrating a configuration of a hot water supply device for a gas boiler according to the related art.

[0021] FIG. 2 is a view illustrating a flow path of heating water during a heating operation in a boiler system for both heating and hot water according to a first embodiment of the present invention.

[0022] FIG. 3 is a view illustrating a flow path of hot water during preheating of hot water in the boiler system for both heating and hot water according to the first embodiment of the present invention.

[0023] FIG. 4 is a view illustrating flow paths of hot water and tap water during the initial use of the hot water in the boiler system for both heating and hot water according to the first embodiment of the present invention.

[0024] FIG. 5 is a view illustrating a flow path of heating water during a heating operation in a boiler system for both heating and hot water according to a second embodiment of the present invention.

[0025] FIG. 6 is a view illustrating a flow path of hot water during preheating of the hot water in the boiler system for both heating and hot water according to the second embodiment of the present invention.

[0026] FIG. 7 is a view illustrating flow paths of hot water and tap water during the initial use of the hot water in the boiler system for both heating and hot water according to the second embodiment of the present invention.

[0027] FIG. 8 is a view illustrating a flow path of heating water during a heating operation in a boiler system for both heating and hot water according to a third embodiment of the present invention.

[0028] FIG. 9 is a view illustrating a flow path of heating water during preheating of hot water in a boiler system for both heating and hot water according to the third embodiment of the present invention.

[0029] FIG. 10 is a view illustrating a flow path of hot water during preheating of the hot water in the boiler system for both heating and hot water according to the third embodiment of the present invention.

[0030] FIG. 11 is a view illustrating flow paths of hot water and tap water during the initial use of the hot water in the boiler system for both heating and hot water according to the third embodiment of the present invention.

[0031] FIG. 12 is a view illustrating a flow path of heating water during a heating operation in a boiler system for both heating and hot water according to a fourth embodiment of the present invention.

[0032] FIG. 13 is a view illustrating a flow path of heating water when preheating of hot water in the boiler system for both heating and hot water according to the fourth embodiment of the present invention.

[0033] FIG. 14 is a view illustrating a flow path of hot water during preheating of the hot water in the boiler system for both heating and hot water according to the fourth embodiment of the present invention.

[0034] FIG. 15 is a view illustrating flow paths of hot water and tap water during the initial use of the hot water in the boiler system for both heating and hot water according to the fourth embodiment of the present invention.

[0035] FIG. 16 is a control block diagram of a boiler system for both heating and hot water according to the present invention.

[0036]

TABLE-US-00001 Descriptions of Reference Numerals 1: gas valve 3: burner 5: heat exchanger 7: exhaust flue 9: tap water supply pipe 9a: hot water return pipe 11: hot water supply pipe 13: temperature sensor 15: water tank 17: circulation pump 19: second circulation pump 21: flow valve V: three-way valve 100-1, 100-2: boiler system 101: heating water supply pipe 102: heating water return pipe 103: tap water pipe 104: tap water supply pipe 105: hot water supply pipe 106: hot water bypass channel 107: hot water recirculation channel 110: hot water storage type heat exchanger 120: heating destination 130: hot water destination 140: circulation pump 150: first three-way valve 160: second three-way valve 170: check valve 200-1, 200-2: boiler system 201: heating water supply pipe 202: heating water return pipe 203: heating water bypass pipe 204: tap water pipe 205: tap water supply pipe 206: hot water supply pipe 207: hot water bypass channel 208: hot water recirculation channel 210: main heat exchanger 220: hot water heat exchanger 230: heating destination 240: hot water destination 250: three-way valve 260: circulation pump 270: first three-way valve 280: second three-way valve 290: check valve 300: room controller 310: heating button 320: water preheating button 330: hot water button 400: control unit B: burner F: air blower

BEST MODES OF THE INVENTION

[0037] Hereinafter, the configurations and operations of exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, solid arrows refer to a flow path of heating water, and hollow arrows refer to a flow path of hot water or tap water.

[0038] Referring to FIGS. 2 to 4, a boiler system 100-1 for both heating and hot water according to a first embodiment of the present invention includes a hot water storage type heat exchanger 110 which stores heating water supplied to a heating destination 120, heats the heating water using a heat source (not shown), and generates hot water through a heat exchange between the heated heating water and tap water.

[0039] A heating water supply pipe 101 and a heating water return pipe 102 are connected between the hot water storage type heat exchanger 110 and the heating destination 120 to form a heating water channel.

[0040] A tap water pipe 103 and a hot water supply pipe 105 are connected to a hot water destination 130.

[0041] A tap water supply pipe 104 is branched from the tap water pipe 103 and is connected to pass through the inside of the hot water storage type heat exchanger 110. The tap water supply pipe 104 inside the hot water storage type heat exchanger 110 is connected to the hot water supply pipe 105. Tap water, which passes through the tap water supply pipe 104 passing through the inside of the hot water storage type heat exchanger 110, is heated through a heat exchange with the heated heating water stored in the hot water storage type heat exchanger 110 and is generated into hot water to be supplied to the hot water supply pipe 105.

[0042] A circulation pump 140 is installed on the heating water return pipe 102 to pump heating water or preheated hot water.

[0043] One end of a hot water bypass channel 106 is connected to the heating water return pipe 102 positioned at an outlet side of the circulation pump 140, and the other end of the hot water bypass channel 106 is connected to the tap water supply pipe 104.

[0044] One end of a hot water recirculation channel 107 is connected to the heating water return pipe 102 positioned at an inlet side of the circulation pump 140, and the other end of the hot water recirculation channel 107 is connected to the hot water supply pipe 105.

[0045] A first three-way valve 150 configured to convert a flow path is provided at a first branch point at which the heating water return pipe 102 and the hot water recirculation channel 107 are connected. A second three-way valve 160 configured to convert a flow path is provided at a second branch point at which the heating water return pipe 102 and the hot water bypass channel 106 are connected.

[0046] Referring to FIG. 2, during a heating operation, the circulation pump 140 is operated, and the first three-way valve 150 forms flow paths such that a flow path toward the heating destination 120 and a flow path toward the circulation pump 140 are opened and a flow path toward the hot water recirculation channel 107 is closed. In addition, the second three-way valve 160 forms flow paths such that the flow path toward the circulation pump 140 and a flow path toward the hot water storage type heat exchanger 110 are opened and a flow path toward the hot water bypass channel 106 is closed.

[0047] Thus, as indicated by arrows in FIG. 2, heating water heated in the hot water storage type heat exchanger 110 is supplied to the heating destination 120 through the heating water supply pipe 101. In addition, the heating water, which transfers heat to the heating destination 120, is returned to the hot water storage type heat exchanger 110 through the heating water return pipe 102 and circulated.

[0048] Referring to FIG. 3, during preheating of hot water, the circulation pump 140 is operated, and the first three-way valve 150 forms flow paths such that the flow path toward the hot water recirculation channel 107 and the flow path toward the circulation pump 140 are opened and the flow path toward the heating destination 120 is closed. In addition, the second three-way valve 160 forms flow paths such that the flow path toward the circulation pump 140 and the flow path toward the hot water bypass channel 106 are opened and the flow path toward the hot water storage type heat exchanger 110 is closed.

[0049] Therefore, as indicated by arrows in FIG. 3, preheated hot water, which is heated by absorbing heat of heating water in the hot water storage type heat exchanger 110, is returned to the hot water storage type heat exchanger 110 via a hot water preheating circulation channel, in which the hot water supply pipe 105, the hot water recirculation channel 107, the first three-way valve 150, the circulation pump 140, the second three-way valve 160, and the hot water bypass channel 106 are connected, and circulated.

[0050] Referring to FIG. 4, when hot water is used in the hot water destination 130 during preheating of the hot water, the circulation pump 140 is operated for a set time, and thus, as shown by arrows in FIG. 4, the preheated hot water is supplied to the hot water destination 130 by the operation of the circulation pump 140. When the set time has elapsed, the operation of the circulation pump 140 is stopped.

[0051] After the preheated hot water present in the hot water preheating circulation channel is supplied to the hot water destination 130, tap water introduced through the tap water pipe 103 is supplied into the hot water storage type heat exchanger 110 through the tap water supply pipe 104, is heated through a heat exchange with the heating water, and then is supplied to the hot water destination 130 through the hot water supply pipe 105.

[0052] As described above, since the preheated hot water remaining in the hot water preheating circulation channel is supplied to a user for the initial use of the hot water, water having a warm temperature desired by the user may be immediately supplied.

[0053] Meanwhile, as shown in FIGS. 2 to 4, the heating water return pipe 102 from the first branch point of the heating water return pipe 102 and the hot water recirculation channel 107 to the second branch point of the heating water return pipe 102 and the hot water bypass channel 106 is used as a common channel through which heating water and preheated hot water selectively flow.

[0054] As described above, since heating water may be mixed into hot water in a section which is used for both of a channel for the heating water and a channel for the preheated hot water, in order to minimize a flow rate at which the heating water is mixed into the hot water, a distance between the branch point of the heating water return pipe 102 and the hot water recirculation channel 107 and the branch point of the heating water return pipe 102 and the hot water bypass channel 106 may be designed to be minimized, which will be equally applied to the following embodiments.

[0055] Hereinafter, the configurations and operations of a boiler system 100-2 for both heating and hot water according to a second embodiment of the present invention will be described with reference to FIGS. 5 to 7, and the same components as those of the above described first embodiment are denoted by the same reference numerals and repetitive descriptions thereof will be omitted.

[0056] The boiler system 100-2 for both heating and hot water according to the second embodiment of the present invention is different from that of the first embodiment in that a second three-way valve 160 is omitted and a check valve 170 is further provided in a hot water bypass channel 106 to allow preheated hot water passing through the hot water bypass channel 106 to flow in only one direction toward a tap water supply pipe 104 and restrict a flow path such that the preheated hot water is blocked from flowing in a direction opposite to the one direction, and other components thereof may be the same as those of the first embodiment.

[0057] Referring to FIG. 5, during a heating operation, a circulation pump 140 is operated, and a first three-way valve 150 forms flow paths such that a flow path toward a heating destination 120 and a flow path toward the circulation pump 140 are opened and a flow path toward a hot water recirculation channel 107 is closed.

[0058] Thus, as indicated by arrows in FIG. 5, heating water heated in a hot water storage type heat exchanger 110 is supplied to the heating destination 120 through a heating water supply pipe 101. In addition, the heating water, which transfers heat to the heating destination 120, is returned to the hot water storage type heat exchanger 110 through a heating water return pipe 102 and circulated.

[0059] In this case, since the first three-way valve 150 is in a state in which the flow path toward the hot water recirculation channel 107 is closed, heating water passing through the circulation pump 140 is prevented from being supplied to a channel in which the hot water bypass channel 106, a hot water supply pipe 105, and the hot water recirculation channel 107 are connected.

[0060] Referring to FIG. 6, during preheating of hot water, the circulation pump 140 is operated, and the first three-way valve 150 forms flow paths such that the flow path toward the hot water recirculation channel 107 and the flow path toward the circulation pump 140 are opened and the flow path toward the heating destination 120 is closed.

[0061] Therefore, as indicated by arrows in FIG. 6, preheated hot water, which is heated by absorbing heat of heating water in the hot water storage type heat exchanger 110, is returned to the hot water storage type heat exchanger 110 via a hot water preheating circulation channel, in which the hot water supply pipe 105, the hot water recirculation channel 107, the first three-way valve 150, the circulation pump 140, and the hot water bypass channel 106 are connected, and circulated.

[0062] In this case, since the first three-way valve 150 is in a state in which the flow path toward the heating destination 120 is closed, preheated hot water passing through the circulation pump 140 is prevented from being supplied to a channel in which the hot water storage type heat exchanger 110, the heating water supply pipe 101, and the heating destination 120 are connected.

[0063] In addition, a backflow phenomenon of tap water may be prevented by the check valve 170 installed on the hot water bypass channel 106, and thus, hot water may be smoothly preheated and circulated.

[0064] Referring to FIG. 7, when hot water is used in a hot water destination 130 during preheating of the hot water, the circulation pump 140 is operated for a set time, and thus, as shown by arrows, the preheated hot water is supplied to the hot water destination 130 by the operation of the circulation pump 140. When the set time has elapsed, the operation of the circulation pump 140 is stopped.

[0065] After the preheated hot water present in the hot water preheating circulation channel is supplied to the hot water destination 130, as shown by arrows, tap water introduced through a tap water pipe 103 is supplied into the hot water storage type heat exchanger 110 through the tap water supply pipe 104, is heated through a heat exchange with the heating water, and then is supplied to the hot water destination 130 through the hot water supply pipe 105.

[0066] The above-described first and second embodiments are embodiments of a case in which the present invention is applied to a hot water storage type boiler system. Hereinafter, third and fourth embodiments of a case in which the present invention is applied to a gas boiler system will be described.

[0067] Referring to FIGS. 8 to 11, a boiler system 200-1 for both heating and hot water according to the third embodiment of the present invention includes a main heat exchanger 210 which heats heating water supplied for heating or supplied for exchanging heat by using combustion heat and a hot water heat exchanger 220 which generates hot water by exchanging heat between the heated heating water, which is heated by the main heat exchanger 210, and tap water. Reference symbol F denotes an air blower configured to supply combustion air, and reference symbol B denotes a burner configured to burn a mixture gas of combustion air and a gas.

[0068] A heating water supply pipe 201 and a heating water return pipe 202 are connected between the main heat exchanger 210 and a heating destination 230 to form a heating water channel.

[0069] A heating water bypass pipe 203 is connected to the heating water supply pipe 201 such that heating water supplied from the main heat exchanger 210 flows toward the heating water return pipe 202 via the hot water heat exchanger 220. A three-way valve 250 configured to selectively convert a flow path of heating water toward the heating destination 230 or the hot water heat exchanger 220 is provided at a branch point of the heating water supply pipe 201 and the heating water bypass pipe 203.

[0070] A tap water pipe 204 and a hot water supply pipe 206 are connected to a hot water destination 240.

[0071] A tap water supply pipe 205 is branched from the tap water pipe 204 and is connected to pass through the inside of the hot water heat exchanger 220. The tap water supply pipe 205 inside the hot water heat exchanger 220 is connected to the hot water supply pipe 206. Tap water, which passes through the tap water supply pipe 205 passing through the inside of the hot water heat exchanger 220, is heated through a heat exchange with heating water passing through the inside of the heating water bypass pipe 203 passing through the hot water heat exchanger 220 and is supplied to the hot water supply pipe 206.

[0072] A circulation pump 260 is installed on the heating water return pipe 202 to pump heating water or preheated hot water.

[0073] One end of a hot water bypass channel 207 is branched and connected to the heating water return pipe 202 positioned at an outlet side of the circulation pump 260, and the other end of the hot water bypass channel 207 is connected to the tap water supply pipe 205.

[0074] One end of a hot water recirculation channel 208 is branched and connected to the heating water return pipe 202 positioned at an inlet side of the circulation pump 260, and the other end of the hot water recirculation channel 208 is connected to the hot water supply pipe 206.

[0075] A first three-way valve 270 configured to convert a flow path is provided at a first branch point at which the heating water return pipe 202 and the hot water recirculation channel 208 are connected. A second three-way valve 280 configured to convert a flow path is provided at a second branch point at which the heating water return pipe 202 and the hot water bypass channel 207 are connected.

[0076] Referring to FIG. 8, during a heating operation, the circulation pump 260 is operated, and the first three-way valve 270 forms flow paths such that a flow path toward the heating destination 230 and a flow path toward the circulation pump 260 are opened and a flow path toward the hot water recirculation channel 208 is closed. In addition, the second three-way valve 280 forms flow paths such that the flow path toward the circulation pump 260 and a flow path toward the main heat exchanger 210 are opened and a flow path toward the hot water bypass channel 207 is closed.

[0077] In addition, the three-way valve 250 forms flow paths such that the flow path toward the heating destination 230 is opened and a flow path toward the heating water bypass pipe 203 is closed.

[0078] Thus, as indicated by arrows in FIG. 8, heating water heated in the main heat exchanger 210 is supplied to the heating destination 230 through the heating water supply pipe 201. In addition, the heating water, which transfers heat to the heating destination 230, is returned to the main heat exchanger 210 through the heating water return pipe 202 and circulated.

[0079] Referring to FIG. 9, during preheating of hot water, in order to store heat in heating water in the hot water heat exchanger 220, the three-way valve 250 forms flow paths such that the flow path toward the heating water bypass pipe 203 is opened and the flow path toward the heating destination 230 is closed.

[0080] Thus, heating water heated in the main heat exchanger 210 passes through the hot water heat exchanger 220 via the heating water supply pipe 201 and the heating water bypass pipe 203 and then is returned to the main heat exchanger 210 through the heating water return pipe 202 and circulated.

[0081] When heat is stored in the heating water in the hot water heat exchanger 220, as shown in FIG. 10, the circulation pump 260 is operated to preheat hot water, and the first three-way valve 270 forms flow paths such that the flow path toward the hot water recirculation channel 208 and the flow path toward the circulation pump 260 are opened and the flow path toward the heating destination 230 is closed. In addition, the second three-way valve 280 forms flow paths such that the flow path toward the circulation pump 260 and the flow path toward the hot water bypass channel 207 are opened and the flow path toward the main heat exchanger 210 is closed.

[0082] Therefore, as indicated by arrows in FIG. 10, preheated hot water, which is heated by absorbing heat of heating water in the hot water heat exchanger 220, is returned to the hot water heat exchanger 220 via a hot water preheating circulation channel, in which the hot water recirculation channel 208, the first three-way valve 270, the circulation pump 260, the second three-way valve 280, the hot water bypass channel 207, and the tap water supply pipe 205 are connected, and circulated.

[0083] During preheating of hot water, operations of FIGS. 9 and 10 may be alternately performed.

[0084] Referring to FIG. 11, when hot water is used in the hot water destination 240 during preheating of the hot water, the circulation pump 260 is operated for a set time, and thus, as shown by arrows, the preheated hot water is supplied to the hot water destination 240 by the operation of the circulation pump 260. When the set time has elapsed, the operation of the circulation pump 260 is stopped.

[0085] After the preheated hot water present in the hot water preheating circulation channel is supplied to the hot water destination 240, as shown by arrows, tap water introduced through the tap water pipe 204 is supplied into the hot water heat exchanger 220 through the tap water supply pipe 205, is heated through a heat exchange with the heated heating water passing through the hot water heat exchanger 220 as shown and described with reference to FIG. 9, and then is supplied to the hot water destination 240 through the hot water supply pipe 206.

[0086] As described above, since the preheated hot water remaining in the hot water preheating circulation channel is supplied to a user for the initial use of the hot water, water having a warm temperature desired by the user may be immediately supplied.

[0087] Hereinafter, the configurations and operations of a boiler system 200-2 for both heating and hot water according to the fourth embodiment of the present invention will be described with reference to FIGS. 12 to 15, and the same components as those of the above described third embodiment are denoted by the same reference numerals and repetitive descriptions thereof will be omitted.

[0088] The boiler system 200-2 for both heating and hot water according to the fourth embodiment of the present invention is different from that of the third embodiment in that a second three-way valve 280 is omitted and a check valve 290 is further provided in a hot water bypass channel 207 to allow preheated hot water passing through the hot water bypass channel 207 to flow in only one direction toward a tap water supply pipe 205 and restrict a flow path such that the preheated hot water is blocked from flowing in a direction opposite to the one direction, and other components thereof may be the same as those of the third embodiment.

[0089] Referring to FIG. 12, during a heating operation, a circulation pump 260 is operated, and a first three-way valve 270 forms flow paths such that a flow path toward a heating destination 230 and a flow path toward the circulation pump 260 are opened and a flow path toward a hot water recirculation channel 208 is closed.

[0090] In addition, a three-way valve 250 forms flow paths such that the flow path toward the heating destination 230 is opened and a flow path toward a heating water bypass pipe 203 is closed.

[0091] Thus, as indicated by arrows in FIG. 12, heating water heated in a main heat exchanger 210 is supplied to the heating destination 230 through a heating water supply pipe 201. In addition, the heating water, which transfers heat to the heating destination 230, is returned to the main heat exchanger 210 through a heating water return pipe 202 and circulated.

[0092] In this case, since the first three-way valve 270 is in a state in which the flow path toward the hot water recirculation channel 208 is closed, heating water passing through the circulation pump 260 is prevented from being supplied to a channel connected in which the hot water bypass channel 207, the tap water supply pipe 205, a hot water supply pipe 206, and a hot water recirculation channel 208 are connected.

[0093] Referring to FIG. 13, during preheating of hot water, in order to store heat in heating water in a hot water heat exchanger 220, the three-way valve 250 forms flow paths such that the flow path toward the heating water bypass pipe 203 is opened and the flow path toward the heating destination 230 is closed.

[0094] Thus, heating water heated in the main heat exchanger 210 passes through the hot water heat exchanger 220 through the heating water supply pipe 201 and the heating water bypass pipe 203 and then is returned to the main heat exchanger 210 through the heating water return pipe 202 and circulated.

[0095] When heat is stored in the heating water in the hot water heat exchanger 220, as shown in FIG. 14, the circulation pump 260 is operated, and the first three-way valve 270 forms flow paths such that the flow path toward the hot water recirculation channel 208 and the flow path toward the circulation pump 260 are opened and the flow path toward the heating destination 230 is closed.

[0096] Therefore, as indicated by arrows in FIG. 14, preheated hot water, which is heated by absorbing heat of heating water in the hot water heat exchanger 220, is returned to the hot water heat exchanger 220 via a hot water preheating circulation channel, in which the hot water recirculation channel 208, the first three-way valve 270, the circulation pump 260, the hot water bypass channel 207, and the tap water supply pipe 205 are connected, and circulated.

[0097] In this case, since the first three-way valve 270 is in a state in which the flow path toward the heating destination 230 is closed, preheated hot water passing through the circulation pump 260 is prevented from being supplied to a channel in which the main heat exchanger 210, the heating water supply pipe 201, and the heating destination 230 are connected.

[0098] In addition, a backflow phenomenon of tap water may be prevented by the check valve 290 installed on the hot water bypass channel 207, and thus, hot water may be smoothly preheated and circulated.

[0099] During preheating of hot water, operations of FIGS. 13 and 14 may be alternately performed.

[0100] Referring to FIG. 15, when hot water is used in a hot water destination 240 during preheating of the hot water, the circulation pump 260 is operated for a set time, and thus, as shown by arrows, the preheated hot water is supplied to the hot water destination 240 by the operation of the circulation pump 260. When the set time has elapsed, the operation of the circulation pump 260 is stopped.

[0101] After the preheated hot water present in the hot water preheating circulation channel is supplied to the hot water destination 240, as shown by arrows, tap water introduced through the tap water pipe 204 is supplied into the hot water heat exchanger 220 through the tap water supply pipe 205, is heated through a heat exchange with the heated heating water passing through the hot water heat exchanger 220 as shown and described with reference to FIG. 13, and then is supplied to the hot water destination 240 through the hot water supply pipe 206.

[0102] FIG. 16 is a control block diagram of the boiler system for both heating and hot water according to the present invention. A room controller 300 may include a heating button 310 for allowing a user to operate a heating function, a water preheating button 320 for allowing the user to operate a hot water preheating function, and a hot water button 330 for allowing the user to operate a hot water function.

[0103] When the user presses and selects one of the heating button 310, the water preheating button 320, and the hot water button 330 provided in the room controller 300, a selected signal is sent to a control unit 400, and the control unit 400 controls operations of the circulation pump 140 or 260, the first three-way valve 150 or 270, and the second three-way valve 160 or 280 to perform a selected function.

[0104] When the user presses the water preheating button 320 to select the hot water preheating function, the control unit 400 may perform a control to operate the circulation pump 140 or 260 for a certain time (for example, 60 seconds) such that the hot water preheating function is operated.

[0105] During the operation of the hot water preheating function, when the user presses the hot water button 330 to select the hot water function, the control unit 400 may perform a control to additionally operate the circulation pump 140 or 260 for a certain time (for example, 60 seconds) such that the hot water preheating function is operated.

[0106] During the operation of the hot water preheating function, when hot water is used in the hot water destination 130 or 240, the control unit 400 may perform a control to stop the operation of the circulation pump 140 or 260 such that hot water supplying function is continuously operated. The control unit 400 may determine whether the hot water is used in the hot water destination 130 or 240 based on a signal sensed by a flow sensor (not shown) provided on the tap water pipe 103 or 204 to sense a flow of tap water.

[0107] On the other hand, in the present specification, it has been described that the circulation pump 140 or 260 transports a fluid in only one direction, but the circulation pump 140 or 260 may be configured to transport the fluid in both directions. In this case, even when the arrangement order of the first and second branch points is reversed from that shown in the drawings, a hot water preheating function may be performed.

[0108] In addition, the hot water recirculation channel 107 or 208 and the hot water bypass channel 106 or 207 may be disposed inside the boiler or may be disposed outside the boiler (in a piping of a house).

[0109] As described above, the present invention is not limited to the described embodiments, and it should be construed that modifications can be apparently devised by those skilled in the art without departing from the technical spirit of the present invention defined by the appended claims, and also such modifications will fall within the scope of the present invention.