JP6633334B2 - Combined heat source machine - Google Patents

Description

  The present invention relates to a composite heat source device including a first heat exchanger and a second heat exchanger, a first burner for heating the first heat exchanger, and a second burner for heating the second heat exchanger.

  Conventionally, as this kind of combined heat source unit, both the first and second burners are constituted by Bunsen type burners such as a light and dark burner, and the combustion air (primary air and secondary air) is supplied to both burners by a common fan. There is known a device that performs such a process (for example, see Patent Document 1).

  In this case, the cost can be reduced by sharing the fan for both burners, but there are the following disadvantages. That is, in the single operation in which only one of the first burner and the second burner is burned to heat one heat exchanger corresponding to the burner, air is supplied to the other burner, and the air is supplied to the other burner. As it passes through the other heat exchanger corresponding to the other burner, the heat exchanger is cooled, and the heat efficiency of the heat exchanger at the time of reheating deteriorates.

  By the way, although it is not a combined heat source unit, conventionally, in a heat source unit having a plurality of burners for heating a single heat exchanger, a plurality of burners are configured by all primary combustion type burners, and a common burner connected to these burners is used. A single fan for supplying primary air is interposed in the air supply path, and the downstream end of the gas supply path for supplying the fuel gas is connected to the upstream or downstream air supply section of the fan, so that the primary air is supplied. A mixture of air and fuel gas is supplied to a plurality of burners via an air supply path, and is supplied to a gas supply path in proportion to a supply amount of primary air so that an air-fuel ratio of the mixture becomes constant. There is known a device in which a flow rate adjusting means for varying a supply amount of fuel gas is provided, and an on-off valve is provided at a connection between each burner and an air supply passage (for example, see Patent Document 2).

  This technology is applied to a combined heat source unit, and the first and second burners for heating the first and second heat exchangers are all composed of primary combustion burners, and the supply is performed by using a single fan. An air-fuel mixture is supplied to both the first and second burners via an air passage, and each open / close valve is provided at a connection between each burner and the air supply passage, so that one of the first burner and the second burner is provided. At the time of the single operation in which only the burner is burned and one of the heat exchangers corresponding to the burner is heated, the on-off valve provided at the connection between the other burner and the air supply path is closed to connect the other burner to the other burner. It is conceivable to stop supplying the mixture. According to this, it is possible to prevent the other heat exchanger corresponding to the other burner that is not burned during the independent operation from being cooled by the airflow from the fan.

  However, this causes the following problems. That is, during the simultaneous operation in which both the first and second burners are burned to heat the first and second heat exchangers, changing the fan rotation speed makes it possible to reduce the amount of air-fuel mixture supplied to the first burner. The supply amount of the air-fuel mixture to the second burner changes together, and the supply amount of the air-fuel mixture to the first burner and the air-fuel mixture supply to the second burner cannot be individually adjusted.

JP 2006-38423 A JP 2010-151395 A

  SUMMARY OF THE INVENTION In view of the above, the present invention provides a composite heat source device capable of individually adjusting the amount of air-fuel mixture supplied to first and second burners that supply air-fuel mixture via a common air supply path. The challenge is to provide.

In order to solve the above-mentioned problems, the present invention provides a first and a second heat exchanger, a first burner for heating the first heat exchanger, and a second burner for heating the second heat exchanger. Wherein the first and second burners are all primary combustion burners, and a single fan for supplying primary air to a common air supply path connected to both the burners. The downstream end of the gas supply path for supplying the fuel gas is connected to a portion of the air supply path on the upstream side or the downstream side of the fan, and a mixture of the primary air and the fuel gas passes through the air supply path. To the first and second burners, and in the gas supply path, the flow rate of the fuel gas which varies in proportion to the supply rate of the primary air so that the air-fuel ratio of the mixture becomes constant. In the case where an adjusting means is provided, a connection between one of the first and second burners and the air supply passage is provided. Flow rate with on-off valve is provided, together with a needle-type flow rate control valve is provided at the connection between the other of the burner and air supply passage, alone during operation to burn only one burner, to open the on-off valve to With the control valve in the fully closed state, the amount of air-fuel mixture supplied to one burner is adjusted to the amount required for one burner by controlling the fan speed, and only the other burner is burned. In the isolated operation, the on-off valve is closed and the flow control valve is fully opened, and the supply amount of the air-fuel mixture to the other burner is controlled to the required combustion amount of the other burner by controlling the rotation speed of the fan. During the simultaneous operation in which both the first and second burners are burned by adjusting the amount to an appropriate value, the amount of air-fuel mixture supplied to one of the burners is controlled by controlling the number of rotations of the fan while the on-off valve is opened. in adjusting Then co the amount corresponding to the required combustion capability of one burner Characterized that you adjust the amount corresponding to the required combustion amount of the other burners in the control of the supply amount of flow rate control valve of the air-fuel mixture to the other burner.

  According to the present invention, during the simultaneous operation of heating both the first and second heat exchangers by burning both the first and second burners, the burner is moved to one of the first and second burners. The amount of the mixture supplied to the other burner is adjusted by controlling the fan rotation speed to an amount corresponding to the required combustion amount of one burner, and the amount of the mixture supplied to the other burner is controlled by the flow control valve. The amount can be adjusted according to the required combustion amount. That is, the supply amount of the mixture to the first burner and the supply amount of the mixture to the second burner can be individually adjusted. Furthermore, since an on-off valve is provided at the connection between one burner and the air supply path, the cost can be reduced as compared with the case where a flow control valve is also provided at this connection.

  Further, in the present invention, when the first burner is a burner having a larger rated combustion amount than the second burner, it is preferable that one of the burners provided with an on-off valve at the connection with the air supply path is the first burner. . According to this, even if the supply amount of the air-fuel mixture to the second burner is increased or decreased by controlling the flow control valve, the supply amount of the air-fuel mixture to the first burner, which is a large burner having a large rated combustion amount, is not so large. Without changing, the combustion amount of the first burner can be maintained at a value close to the required combustion amount. Therefore, accurate cooperative control between the fan speed and the flow control valve is not required, and control is facilitated.

FIG. 1 is a schematic cross-sectional view illustrating a composite heat source device according to an embodiment of the present invention.

Composite heat source unit of an embodiment of the present invention shown in FIG. 1, the heat from the first heat exchanger 1 ₁ for hot water supply, and the second heat exchanger 1 ₂ for heating, the first heat exchanger 1 ₁ It includes a 1 burner _{2 1,} and a second burner _{2 2} for heating the second heat exchanger _{1 2.}

The first and the burner 2 _{1 second,} 2 _2, the mixture from the plurality of burner ports formed in the combustion plate 22 which covers the one surface of the box-shaped burner body 21 (not shown) and the fuel gas and the primary air The burner is composed of an all-primary combustion type burner that blows out and burns, and is disposed in a downward position with the combustion plate 22 facing down. Then, the first and second respective burners 2 _1, 2 ₂ of the first surrounding the combustion space under a second respective combustion housing 3 _1, 3 ₂ is provided in the first and second respective combustion housing 3 _{1, 3} to ₂ lower housing the first and second of each heat exchanger ₁ 1, _{1 2.} Further, by providing the exhaust duct 4 communicating with both the first and second combustion housing 3 _1, 3 ₂ of the lower end, the combustion exhaust gas from the first and the burner 2 _{1 second,} 2 ₂ and the first to each heat exchanger 1 _{1 2,} 1 ₂ through which to flow the exhaust duct 4.

Note that the order towards the hot water supply is required a large heat capacity, large large burner a first burner 2 ₁ rated combustion amount than the second burner 2 ₂ (maximum combustion amount) than heating. The exhaust duct 4 is partitioned into a duct section combustion exhaust gas from the duct section and the second burner 2 ₂ flowing in the partition plate 41 provided therein flue gas from the first burner 2 ₁ flows.

The first and second of each heat exchanger 1 _1, 1 _2, the heat absorbing fin 11 which is many stacked perpendicular to the drawing surface of FIG. 1, is composed of a heat absorbing tube 12 of serpentine shape through these heat absorbing fin 11 I have. The first heat absorbing tube 12 of the heat exchanger 1 _1, although not shown, the upstream side of the water supply pipe and the downstream hot water tube is connected, a first heat open pouring plug the downstream end of the hot water pipe when passed through the exchanger 1 _1, the first burner 2 ₁ burns, hot water set temperature from hot water tap is tapped. The second heat absorbing tube 12 of the heat exchanger 1 _2, although not shown, via the return forward pipe line is connected to a heating circuit of the floor heating or the like, the second heat exchanger 1 ₂ through the heating circuit Circulates warm water to heat.

The first and second on both the burner 2 _1, 2 ₂ are connected to a common air supply passage 5, in this air supply passage 5, interposed a single fan 6 for supplying primary air are doing. The gas outlet 71 at the downstream end of the gas supply path 7 for supplying the fuel gas to the air supply path 5 on the upstream side of the fan 6 is connected. The portion of the air supply passage 5 connecting the gas outlet 71 is a venturi portion 51 having a reduced cross-sectional area.

  The gas supply path 7 is provided with a main valve 72 and a zero governor 73 as a flow rate adjusting means for adjusting the secondary gas pressure to the same pressure as the atmospheric pressure. Here, the supply amount of the fuel gas changes according to the differential pressure between the atmospheric pressure, which is the secondary gas pressure, and the suction negative pressure of the fan 6 acting on the venturi section 51. Since the fan suction negative pressure changes in proportion to the fan rotation speed, the supply amount of the fuel gas changes in proportion to the fan rotation speed, that is, the supply amount of the primary air, and the air-fuel ratio of the air-fuel mixture becomes constant.

Further, the connecting portion 2 _{1 a} of the first burner 2 ₁ and air supply passage 5, the opening and closing valve 8 is provided which is driven by an actuator 81 such as an electromagnetic solenoid, a second burner 2 ₂ and supply passageway 5 the connection part 2 _{2 a,} the flow rate control valve 9 of the needle type is provided which is driven by an actuator 91 that combines the screw feed mechanism to the electric motor.

Then, with only the first burner 2 ₁ by burning during the single hot water supply operation for heating the first heat exchanger 1 _1, supplying the mixture off valve 8 in the first burner 2 ₁ is opened, the flow rate the regulating valve 9 to stop the supply of the air-fuel mixture to the second burner 2 ₂ in the fully closed, further, the supply amount of the mixture into the first burner 2 ₁ tapping hot water of the hot water supply demand combustion quantity (set temperature Is adjusted by the rotation speed of the fan 6 so as to have a value corresponding to the combustion amount required for the above. Further, only the second burner 2 ₂ is burned during the heating alone operation for heating the second heat exchanger 1 ₂ supplies the mixture to the second burner 2 ₂ by the flow rate control valve 9 is fully opened, the opening and closing valve 8 stops supplying the mixture to the first burner 2 ₁ closes the further heating demand combustion amount the supply amount of the air-fuel mixture to the second burner 2 ₂ (supplying hot water set to the heating circuit temperature The number of revolutions is adjusted by the number of revolutions of the fan 6 so as to have a value corresponding to the amount of combustion required to perform the combustion.

While heating the first heat exchanger 1 ₁ by burning a first burner 2 _1, at the time of simultaneous operation of the hot water supply and heating to heat the second heat exchanger 1 ₂ by burning the second burner 2 _2-off valve 8 in a state of being opened, adjusted by the rotation speed of the fan 6 such that the value corresponding to the supply amount of the mixture into the first burner 2 ₁ hot water supply demand combustion amount. In this case, while the flow rate control valve 9 was fully opened, and the supply amount of the mixture increases or decreases to the second burner 2 ₂ at a rotational speed increase or decrease of the fan 6, heating demand a second combustion amount of burners 2 ₂ It is not possible to maintain the combustion amount. Therefore, in this embodiment, to adjust the time of simultaneous operation, the flow rate control valve 9 to a value corresponding to the supply amount of the air-fuel mixture to the second burner 2 ₂ heating demand combustion amount. In this way, even during simultaneous operation, depending supplied amount of the mixture into the first burner 2 ₁ and the supply amount of the mixture of the second to the burner 2 ₂ to the required combustion amount of each burner 2 _1, 2 ₂ Can be adjusted individually.

Incidentally, it is conceivable that also the connection portion 2 _{1 a} of the first burner 2 ₁ and supply passageway 5 is provided a flow control valve, as in the present embodiment, the valve provided in the connecting portion 2 _{1 a} closing valve If 8, the cost can be reduced, which is advantageous.

The first burner 2 ₁ and supply passageway 5 and the connecting portion 2 _{1 a} in the flow control valve, the opening and closing valve is provided, at the time of simultaneous operation to the connecting part 2 _{2 a} and the second burner 2 ₂ and supply passageway 5 , the supply amount of the air-fuel mixture to the second burner 2 ₂ adjusted by the rotation speed of the fan 6, can be the supply amount of the mixture into the first burner 2 ₁ regulates the flow rate control valve. However, this in order to vary widely the supply amount of the air-fuel mixture in the regulation of the supply amount of the mixture to the second burner 2 ₂ compact to the first burner 2 ₁ large, and the fan speed and the flow rate control valve Requires precise cooperative control, and the control becomes complicated.

In contrast, according to the present embodiment, even if increase or decrease the supply amount of the air-fuel mixture to the second burner 2 ₂ small control flow control valve 9, the air-fuel mixture into the first burner 2 ₁ Large supply amount does not not that much change can be maintained first combustion amount of burners 2 ₁ to a value close to the required combustion amount. Therefore, precise cooperative control between the fan rotation speed and the flow control valve 9 is not required, and control is facilitated.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited thereto. For example, a venturi portion is provided in a portion of the air supply passage 5 on the downstream side of the fan 6 so that the downstream end of the gas supply passage 7 faces the venturi portion, and a secondary gas pressure is provided to the gas supply passage 7 as flow rate adjusting means. A zero governor for adjusting the pressure to the same pressure as the outlet pressure of the fan 6 may be provided. In this case, since the differential pressure between the outlet pressure of the fan 6 and the venturi section is proportional to the supply amount of the primary air by the fan 6, the supply amount of the fuel gas is also proportional to the supply amount of the primary air.

It is also possible to provide a proportional valve as a flow rate adjusting means in the gas supply path 7 and to adjust the supply amount of the fuel gas by the proportional valve so as to be proportional to the supply amount of the primary air. In this case, the downstream end of the gas supply path may be connected to either the upstream or downstream part of the air supply path 5. Furthermore, the above-described embodiment, the first hot water supply heat exchanger 1 _1, but the second heat exchanger 1 ₂ is a composite heat source unit of a hot water supply and heating to a heating, the second heat exchanger 1 ₂ bath The present invention can be similarly applied to a composite heat source unit for use other than heating such as reheating.

1 1 _... first heat exchanger, 1 2 _... second heat exchanger, 2 1 _... first burner, 2 2 _... second burner, _{2 1} a ... connection portion between the first burner and the air supply passage, _{2 2} a: connection between the second burner and the air supply path, 5: air supply path, 6: fan, 7: gas supply path, 71: gas outlet (downstream end of the gas supply path), 73: zero governor (flow rate adjusting means) ), 8: open / close valve, 9: flow control valve.

Claims (2)

A combined heat source machine comprising first and second two heat exchangers, a first burner for heating the first heat exchanger, and a second burner for heating the second heat exchanger, wherein The second burners are composed of all primary combustion burners. A single fan for supplying primary air is interposed in a common air supply passage connected to both burners, and a gas supply for supplying fuel gas is provided. The downstream end of the passage is connected to a portion of the air supply passage on the upstream or downstream side of the fan, and a mixture of primary air and fuel gas is supplied to both the first and second burners via the air supply passage. In the gas supply path, there is provided a flow control means for varying the supply amount of the fuel gas in proportion to the supply amount of the primary air so that the air-fuel ratio of the air-fuel mixture is constant.
An on-off valve is provided at a connection between one of the first and second burners and the air supply passage, and a needle type flow control valve is provided at a connection between the other burner and the air supply passage. And
During single operation in which only one of the burners is burned, the amount of air-fuel mixture supplied to one of the burners is controlled by controlling the fan speed while the on-off valve is opened and the flow control valve is fully closed. During the single operation in which only the other burner is burned, the mixture is mixed with the other burner with the on-off valve closed and the flow control valve fully opened. The air supply amount was adjusted to an amount corresponding to the required combustion amount of the other burner by controlling the rotation speed of the fan, and the open / close valve was opened during simultaneous operation in which both the first and second burners were burned. state, while adjusting the amount of the supply amount of the mixture according to the required combustion capability of one of the burners at a rotation speed control of the fan to one of the burners, the amount flow the supply amount of the mixture to the other burner adjust the amount corresponding to the required combustion amount of the other burners in the control of the regulating valve Composite heat source apparatus, characterized in that.   2. The combined heat source device according to claim 1, wherein the first burner is a burner whose rated combustion amount is larger than the second burner, wherein the one-side valve is provided at a connection portion with the air supply passage. 3. 2. The combined heat source machine according to claim 1, wherein the first burner is a first burner.

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