JP2010019493A - Latent heat recovery type heat source machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of a latent heat recovery type heat source machine comprising a main heat exchanger for heating a heating medium, an auxiliary heat exchanger for recovering the latent heat of combustion exhaust gas, a cistern interposed in a heating circulation circuit, and the heating circulation circuit having the heating medium circulated therein and including heating going piping for guiding the heating medium heated by the main heat exchanger to a radiator, heating return piping for guiding the heating medium of which heat is released by the radiator to the auxiliary heat exchanger, first connection piping for guiding the heating medium of which latent heat is recovered by the auxiliary heat exchanger to the cistern and a bypass passage for guiding part of the heating medium made to flow in the heating going pipe to the cistern. <P>SOLUTION: An inflow port 84 is provided at an upper end of the cistern 8, and a downstream end of the first connection piping 73 is connected to the inflow port 84. Preferably, a guide pipe 85 for guiding the heating medium made to flow in from the inflow port 84 to the lower side from the lower end of a low water level electrode 81 arranged inside the cistern 8 is provided within the cistern 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a latent heat recovery type heat source apparatus that recovers latent heat in combustion exhaust gas of a burner and heats a heat medium.

  Conventionally, a heating circulation circuit that is connected to a radiator and the heat medium is circulated by a circulation pump, a main heat exchanger that is interposed in the heating circulation circuit and heats the heat medium by combustion of a burner, and a heating circulation circuit A latent heat recovery type heat source device comprising an auxiliary heat exchanger for recovering the latent heat of combustion exhaust gas from the burner and a cistern interposed in the heating circulation circuit, wherein the heating circulation circuit is a main heat exchanger A heating return pipe that leads the heat medium heated by the radiator to the radiator, a heating return pipe that leads the heat medium radiated by the radiator to the systern, a pipe that leads the heat medium in the systern to the sub heat exchanger, What is equipped with the piping which guides the heat medium which collect | recovered latent heat with the exchanger to a main heat exchanger is known (for example, refer patent document 1). The downstream end of the heating return pipe is connected to an inlet provided at the bottom of the cistern.

  By the way, when the burner is burning due to a failure or the like even though the radiator has stopped operating, the heat exchanger may be abnormally heated and broken. Therefore, in such a case, in order to prevent the heat exchanger from heating abnormally, in the heat source apparatus including the heating circulation circuit, a bypass path that guides a part of the heat medium flowing through the heating outgoing piping to the heating circulation circuit to the systern is provided. It is conceivable that the heat medium in the heat exchanger is circulated even when the heat radiator is stopped. However, when this bypass path is provided in the one of Patent Document 1, the heat medium heated by the main heat exchanger flows into the cistern through the bypass path, and the temperature of the heat medium in the cistern rises. Therefore, there is a problem that the temperature of the heat medium sent to the sub heat exchanger becomes relatively high, and the recovery efficiency of latent heat in the sub heat exchanger is lowered.

  Therefore, in the heat source apparatus having such a bypass path, the heating circulation circuit is connected to the heating forward pipe that leads the heat medium heated by the main heat exchanger to the radiator and the heat medium radiated by the radiator. A heating return pipe that leads directly to the heat exchanger, a first connection pipe that leads the heat medium that has recovered latent heat in the auxiliary heat exchanger to the systern, and a second connection pipe that leads the heat medium in the systern to the main heat exchanger What was comprised is also known (for example, refer patent document 2). The downstream end of the first connection pipe is connected using an inflow port provided at the bottom of the cistern to which the heating return pipe was connected.

As a result, the heat medium radiated by the radiator can be guided to the auxiliary heat exchanger before the temperature is raised by the merge of the heat medium from the bypass, and the latent heat in the burner flue gas is efficiently recovered. can do.
JP 2006-336939 A JP 2005-61677 A

  In the conventional latent heat recovery type heat source machine, the auxiliary heat exchanger is arranged at the upper part of the heat source machine, and the cistern is arranged below the auxiliary heat exchanger. And in order to connect the 1st connection piping to the inflow port provided in the bottom of the cistern, it is necessary to extend the 1st connection piping from the upper part to the lower part of the cistern. For this reason, a space for extending the first connection pipe from the upper side to the lower side of the systern is required in the heat source unit, and there is a problem that the heat source unit cannot be reduced in size.

  In view of the above points, an object of the present invention is to provide a latent heat recovery type heat source machine that can be downsized.

  To achieve the above object, the present invention provides a heating circulation circuit connected to a radiator and circulating a heat medium by a circulation pump, and a main heat that heats the heating medium by combustion of a burner interposed in the heating circulation circuit. A latent heat recovery type heat source device comprising: an exchanger; a sub heat exchanger interposed in a heating circulation circuit for recovering latent heat of combustion exhaust gas of a burner; and a systern interposed in a heating circulation circuit, The circulation circuit is composed of a heating return pipe that leads the heat medium heated by the main heat exchanger to the radiator, a heating return pipe that leads the heat medium radiated by the radiator to the sub heat exchanger, and a sub heat exchanger. A first connection pipe that leads the heat medium that has recovered latent heat to the systern, a second connection pipe that leads the heat medium in the systern to the main heat exchanger, and a bypass path that leads a part of the heat medium flowing through the heating forward pipe to the systern And those that have An inlet provided in the upper portion, the downstream end of the first connection pipe is characterized in that it is connected to the inlet port.

  According to the present invention, in order to connect the downstream end of the first connection pipe that guides the heat medium whose latent heat has been recovered by the auxiliary heat exchanger to the cistern, the first connection pipe is connected to the upper end of the cistern. There is no need to extend from above to below, and this makes it possible to reduce the size of the heat source device.

  By the way, the cistern includes a low water level electrode for detecting the low water level of the internal heat medium, a high water level electrode for detecting the high water level of the heat medium, and a heat medium supply pipe for replenishing the heat medium. When the amount of is less than or equal to the low water level electrode, the heat medium is supplied from the heat medium supply pipe until it reaches the high water level electrode. Here, when an inlet is provided at the upper end of the cistern and the downstream end of the first connecting pipe is connected to the inlet, the heat medium flowing from the inlet directly contacts the water level electrode or is stored in the cistern. There is a risk that the water level electrode may erroneously detect the amount of the heat medium in the cistern due to the splash of the heat medium that is scattered when the heat medium flowing from the inlet falls on the liquid surface of the heat medium that is in contact with the water level electrode. .

  In this case, if a guide pipe that guides the heat medium flowing from the first connection pipe through the inlet through the inlet is provided below the lower end of the low water level electrode, the heat medium flowing from the inlet by the guide pipe is low. Since it is guided below the lower end of the water level electrode, the heat medium flowing from the inflow port does not directly contact both the level electrodes. Further, since the heat medium is supplied from the heat medium supply pipe so that the amount of the heat medium in the cistern does not become lower than the low water level electrode, the lower end edge of the guide pipe is always located below the liquid level of the heat medium. Therefore, splashing of the heat medium can be prevented, and erroneous detection of the amount of the heat medium in the cistern of both water level electrodes can be prevented.

  With reference to FIG. 1, reference numeral 1 denotes a latent heat recovery type heat source machine, which constitutes a hot water heating system that performs heating by circulating hot water heated by the heat source machine 1 to a heating radiator 2 such as a floor heating panel. . The heat source device 1 is provided with a combustion soot 3, and a burner 4 and a heat exchanger 5 heated by the burner 4 are accommodated in the combustion soot 3. Combustion air is supplied into the combustion soot 3 by a combustion fan 6.

  A gas main valve 41 and a gas proportional valve 42 are interposed in the gas passage 40 for supplying fuel gas to the burner 4. The burner 4 is composed of a plurality of unit burners 4a. These unit burners 4a are assembled into three burner groups 4b, and the gas passages 40 are branched for each burner group 4b of the unit burner 4a on the downstream side of the gas proportional valve 42, and each burner group 4b is divided into each branch path. A capacity switching valve 43 for supplying fuel gas is provided. Thus, the combustion amount of the burner 4 can be varied over a wide range by combining the control of the capacity switching valve 43 and the control of the gas proportional valve 42.

  The heat exchanger 5 includes a main heat exchanger 51 disposed immediately above the burner 4 and a sub heat exchanger 52 disposed in an exhaust passage through which combustion exhaust gas that has passed through the main heat exchanger 51 flows. In the auxiliary heat exchanger 52, water vapor in the combustion exhaust gas is condensed and latent heat is recovered. When the latent heat is recovered, drain is dripped from the auxiliary heat exchanger 52. This drain is recovered by the drain pan 52a disposed immediately below the auxiliary heat exchanger 52 and guided to the neutralizer 52b, and the neutralizer 52b. The water is neutralized and drained from the drain pipe 52c.

  In addition, the heat source unit 1 is provided with a heating circulation circuit 7 for circulating hot water between the heat exchanger 5 and the heating radiator 2 by a circulation pump 7a. The heat source unit 1 includes a systern 8 interposed in the heating circulation circuit 7. The heating circulation circuit 7 includes a heating forward pipe 71 that guides the hot water heated by the main heat exchanger 51 to the heating radiator 2, and a heating return pipe that guides the hot water radiated by the heating radiator 2 to the auxiliary heat exchanger 52. 72, a first connection pipe 73 that guides the hot water whose latent heat in the combustion exhaust gas has been recovered by the auxiliary heat exchanger 52 to the systole, and a second connection pipe 74 that guides the hot water in the cistern 8 to the main heat exchanger 51. Composed. The circulation pump 7 a is interposed in the second connection pipe 74.

  A bypass path 71 a that guides a part of the hot water heated by the main heat exchanger 51 to the systern 8 is connected to the piping 71 for heating. Thereby, even if the burner 4 is burning due to a failure or the like when the heating radiator 2 is stopped, the second connection pipe 74 and the main heat exchange are activated by operating the circulation pump 7a. The hot water can be circulated through the heater 51, the heating forward pipe 71, the bypass passage 71a, and the cistern 8, and the main heat exchanger 51 can be prevented from being abnormally heated.

  The cistern 8 is replenished with water as a heat medium through a heat medium supply pipe 80 provided with an on-off valve 80a. Then, two water level electrodes 81 and 82 for detecting a low water level and a high water level are provided in the cis turn 8, and when the water level in the cis turn 8 becomes lower than the low water level electrode 81, the on-off valve 80a is opened and the water level is high. Water is supplied until the water level electrode 82 is reached.

  In addition, an overflow pipe 83 is connected to the cistern 8 for discharging water in the cistern 8 when the water level exceeds a predetermined upper limit due to thermal expansion of water. The downstream end of the overflow pipe 83 is connected to the neutralizer 52b, and the water discharged from the overflow pipe 83 is drained from the drain pipe 52c through the neutralizer 52b.

  An inflow port 84 is provided at the upper end of the cistern 8, and the downstream end of the first connection pipe 73 is connected to the inflow port 84. Thus, unlike the conventional case, the first connection pipe is extended from the auxiliary heat exchanger located above the cistern to the lower side of the cistern and connected to the inlet provided at the lower end portion of the cistern. The pipe 73 can be connected to the inlet 84 provided at the upper end portion of the cistern 8 without extending to the lower side of the cistern 8, and the heat source device 1 can be downsized.

  In addition, a guide pipe 85 is provided in the cistern 8 so that the heat medium flowing from the first connection pipe 73 through the inlet 84 is positioned below the lower end of the low water level electrode 81. As a result, the heat medium flowing from the inlet 84 via the guide pipe 85 is guided below the lower end of the low water level electrode 81, so that the heat medium flowing from the inlet 84 does not directly contact the water level electrodes 81, 82. . Further, since the heat medium is supplied from the heat medium supply pipe 80 so that the amount of the heat medium in the cistern 8 does not become lower than the low water level electrode 81, the lower end edge of the guide pipe 85 is always below the liquid level of the heat medium. Located in. Therefore, splashing of the heat medium can be prevented, and erroneous detection of the amount of the heat medium in the cistern 8 of both the water level electrodes 81 and 82 can be prevented.

  The heat source unit 1 is provided with a controller 9. The controller 9 performs heating operation processing when the operation switch of the heating radiator 2 is turned on, and opens the on-off valve 80a when the water level in the cistern 8 becomes lower than the low water level electrode 81, and the water level is high level electrode. When reaching 82, the on-off valve 80a is closed.

  In addition, the controller 9 performs a cleaning process under predetermined conditions, for example, after a predetermined number of preset heating operation processes have been performed. The cleaning process will be described in detail. First, the controller 9 opens the on-off valve 80a of the heat medium supply pipe 80 and supplies water to the cistern 8. Then, even if the water level in the cistern 8 reaches the high water level electrode 82, the supply of water is continued to make the amount of water in the cistern 8 exceed the upper limit, and the water is forcibly discharged from the overflow pipe 83. The water forcedly discharged from the overflow pipe 83 flows into the neutralizer 52b and cleans the neutralizer in the neutralizer 52b. And the water which flowed in the neutralizer 52b from the overflow pipe 83 is discharged | emitted from the drain pipe 52c with a neutralization reaction product. Thereby, the neutralization reaction product adhering to the surface of the neutralizing agent filled in the neutralizer 52b can be washed away, and a decrease in neutralization performance of the neutralizer 52b can be suppressed.

  In the embodiment, water is used as the heat medium. However, the heat medium is not limited to this, and other heat medium may be used as long as the neutralizer in the neutralizer 52b can be washed appropriately. .

  Further, as the heating radiator 2, for example, the heating medium circulation circuit 7 having a high-temperature side radiator such as a bathroom heater and a low-temperature side radiator such as a floor heating panel can be similarly applied. it can.

  In this case, for example, a high-temperature side radiator is provided instead of the heating radiator 2, and the low-temperature side radiator is provided with a low-temperature side outgoing pipe that guides a part of the heat medium flowing through the second connection pipe to the low-temperature side radiator. Thus, the heat medium supplied and the heat medium radiated by the low-temperature side radiator may be configured to be guided to the heating return pipe 72 via the low-temperature side return pipe.

  At this time, since the bypass path 71a guides a part of the heat medium heated by the main heat exchanger 51 to the cistern 8, the temperature of the heat medium from which the latent heat has been recovered by the auxiliary heat exchanger 52 is It will rise further by the confluence of the heat medium from 71a. Therefore, the bypass path 71a also plays a role of increasing the temperature of the heat medium supplied to the low-temperature side radiator.

Explanatory drawing which shows embodiment of the latent heat recovery type heat source machine of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Latent heat recovery type heat source machine, 2 ... Heating radiator, 4 ... Burner, 51 ... Main heat exchanger, 52 ... Sub heat exchanger, 7 ... Heating circulation circuit, 7a ... Circulation pump, 71 ... Heating piping, 71a ... Bypass passage, 72 ... Heating return pipe, 73 ... First connection pipe, 74 ... Second connection pipe, 8 ... Systurn, 80 ... Heat medium supply pipe, 81 ... Low water level electrode, 82 ... High water level electrode, 84 ... Inlet, 85 ... guide pipe.

Claims (2)

A heating circulation circuit connected to a radiator and circulating a heat medium by a circulation pump, a main heat exchanger that is interposed in the heating circulation circuit and heats the heat medium by combustion of a burner, and is interposed in the heating circulation circuit A latent heat recovery type heat source device comprising a sub heat exchanger that recovers the latent heat of the combustion exhaust gas of the burner, and a cistern interposed in the heating circulation circuit,
The heating circulation circuit includes a heating forward pipe that guides the heat medium heated by the main heat exchanger to the radiator, a heating return pipe that leads the heat medium radiated by the radiator to the auxiliary heat exchanger, and the auxiliary heat exchanger. A first connection pipe that leads the heat medium that has recovered latent heat to the systern, a second connection pipe that leads the heat medium in the systern to the main heat exchanger, and a bypass that leads a part of the heat medium flowing through the heating forward pipe to the systern In the thing with road,
An inflow port is provided at an upper end portion of the cistern, and a downstream end of the first connection pipe is connected to the inflow port. 2. The latent heat recovery type heat source apparatus according to claim 1, wherein the cistern includes a low water level electrode that detects a low water level of an internal heat medium, a high water level electrode that detects a high water level of the heat medium, and a heat medium that replenishes the heat medium. A latent heat recovery type heat source machine comprising a replenishment pipe, and a guide pipe for guiding a heat medium flowing from the first connection pipe to the lower side of the low water level electrode via an inlet in the systern.