JP3880136B2 - Combustion device - Google Patents

Description

[0001]
[Technology to which the invention belongs]
The present invention relates to a one-can two-water channel combustion apparatus in which a hot water supply channel and a bath retreat channel pass through a common heat exchanger.
[0002]
[Prior art]
FIG. 7 is a view showing a cross section of the heat exchanger 1 of the single-can two-water channel combustion apparatus. As shown in FIG. 7, a bath retreat path 20 is provided on the side opposite to the burner side in contact with the hot water supply path 10 provided on the burner side. Accordingly, the water in the bath reheating channel 20 is indirectly heated using hot water in the hot water supply channel 10 in the heat exchanger 1 as a heat medium. In this way, the amount of heat of the heated hot water in the hot water supply passage 10 is transferred to the hot water flowing through the bath reheating passage 20.
[0003]
Accordingly, even when the bath is chasing alone without using the hot water supply, the water in the hot water supply passage 10 is heated and the water in the hot water supply passage 10 does not flow, so the temperature becomes very high.
[0004]
And if the water in the hot water supply path 10 continues to be heated, it will boil, and if a hot water supply request is made in such a case, the hot water supply characteristics will be deteriorated. In addition, the pressure in the pipe increases, which is dangerous.
[0005]
Therefore, in order to avoid the boiling of the water temperature in the hot water supply passage 10, a thermistor is arranged at a predetermined position (not shown) in the heat exchanger 1, and the water temperature at the predetermined position in the hot water supply passage 10 is changed when the bath is chasing alone. Combustion is intermittently controlled so as not to exceed a predetermined temperature (for example, 85 degrees).
[0006]
FIG. 8 is a diagram showing a change in the water temperature in the hot water supply passage 10 when intermittent combustion control is performed. The OFF temperature at which combustion is stopped in intermittent combustion control is 90 degrees, and the ON temperature at which combustion is started is 89 degrees. When the temperature of the thermistor reaches 90 degrees, gas supply is stopped and combustion is stopped. The water temperature of the water in the hot water supply passage 10 in the heat exchanger 1 rises by so-called post-boiling even after the combustion is stopped. It is necessary to set the OFF temperature to a temperature that takes into account this water temperature rise. Furthermore, when the combustion stops, the water temperature in the hot water supply passage 10 decreases, and when the water temperature reaches 89 degrees which is the ON temperature, combustion is started again. As described above, when bathing is performed, the stop and start of combustion are repeated in order to avoid boiling in the hot water supply passage 10.
[0007]
[Problems to be solved by the invention]
By the way, the water temperature in the hot water supply path 10 varies depending on the heat transfer amount to the bath reheating path 20, and the heat transfer amount varies depending on the amount of water flowing in the bath reheating path 20. That is, the smaller the amount of water circulating in the bath reheating channel 20, the smaller the amount of heat transferred to the bath retreating side and the higher the water temperature in the hot water supply channel 10. Therefore, as shown by the dotted line in FIG. 8, if the circulation amount is small, the water temperature in the hot water supply channel 10 may reach the boiling point and boil after the combustion is stopped in the intermittent combustion control.
[0008]
The amount of circulation in the bath follow-up path 20 changes due to a secular change such as clogging due to the pipe length of the bath follow-up path 20 or dust attached to the filter installed therein.
[0009]
Therefore, the ON / OFF temperature in the intermittent combustion control has to be set low (for example, 84/85 degrees) in accordance with the case where the circulation amount is small from the viewpoint of safety. That is, when bathing, only a combustion operation with a low combustion capacity can be performed, and it takes a long time to bathe.
[0010]
Accordingly, an object of the present invention is to provide a combustion apparatus that can recharge a bath with as high a combustion capacity as possible while suppressing the water temperature in the hot water supply passage 10 to a predetermined temperature or less that does not boil.
[0011]
In order to achieve the above object, a first configuration of the present invention is a canned two-water channel combustion apparatus in which a hot water supply channel and a bath reheating channel connected to a bathtub pass through a common heat exchanger. The temperature detection means for detecting the water temperature of the water and when the bath reheating is performed without hot water supply , the stop temperature for stopping the combustion is set higher as the circulation amount of the bath retreating path increases. A combustion control means for stopping combustion when the temperature detected by the temperature detection means exceeds the stop temperature, and a predetermined amount of circulation corresponding to the set stop temperature in the bath retreat path. A can-two-water channel combustion apparatus comprising a circulation amount control means for controlling a circulation amount.
[0012]
Further, according to a second configuration of the present invention, in the first configuration, when the circulation amount control unit cannot maintain the predetermined circulation amount, the combustion control unit controls the circulation amount controlled by the circulation amount control unit. The canned two-water channel combustion apparatus is characterized in that the set stop temperature is changed according to the above .
[0013]
Further, according to a third configuration of the present invention, in the first configuration, the circulation amount control means is configured to perform the bath replenishment based on a drive current of a pump that guides and circulates water in the bathtub to the bath retreat channel. A can-and-two-channel combustion apparatus characterized by controlling the amount of circulation in the watering path .
[0014]
According to a fourth configuration of the present invention, in the first configuration, a water amount detection means for detecting the amount of water flowing through the bath retreat path is provided, and the circulation amount control means is detected by the water amount detection means. It is a can and two water channel type combustion device characterized by controlling the amount of circulation in the bath retreat channel based on the amount of water .
[0015]
Further, according to a fifth configuration of the present invention, in the second configuration, an error signal is output when the circulation amount in the bath retreating path becomes a predetermined reference amount less than the predetermined circulation amount. This is a one-can two-water channel combustion apparatus.
[0016]
According to a sixth aspect of the present invention , there is provided a single-can two-water channel combustion apparatus according to the fourth aspect, wherein the pump is a direct current pump .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to this embodiment.
[0021]
FIG. 1 is a schematic configuration diagram of a single-can two-water channel combustion apparatus. In FIG. 1, a hot water supply path 10 and a bath reheating path 20 pass through a common heat exchanger 1. The heat exchanger 1 is heated by a burner 3, and fuel gas is supplied to the burner 3 from a gas supply pipe 4. The gas supply pipe 4 is provided with a gas solenoid valve 5 for opening and closing the gas supply pipe 4 and a gas proportional valve 6 for adjusting the gas supply amount.
[0022]
The hot water supply passage 10 is connected to the inlet side of the heat exchanger 1, connected to the water supply pipe 11 that functions as a water supply passage for supplying water to the heat exchanger 1, and the outlet side of the heat exchanger 1. A hot water pipe 12 through which hot water heated by the hot water is discharged is connected and guided to a desired place such as a hot water tap 16 of the kitchen.
[0023]
The water supply pipe 11 is provided with a flow sensor 13 for detecting the amount of water supply and a water supply temperature sensor 14 for detecting the water supply temperature. Moreover, the hot water supply pipe 12 is provided with a hot water supply temperature sensor 15 for detecting the hot water supply temperature.
[0024]
A heat exchange temperature sensor 17 for measuring the water temperature of the hot water supply passage 10 in the heat exchanger 1 is provided at a predetermined position of the hot water supply passage 10 in the heat exchanger 1.
[0025]
On the other hand, the bath reheating channel 20 supplies the water in the bathtub 22 to the heat exchanger 1 by operating the circulation pump 21 arranged there, and the hot water heated in the heat exchanger 1 is again in the bathtub 22. It constitutes a circulation path poured into the water.
[0026]
A bath water temperature sensor 23 that detects the water temperature in the bathtub 22 is provided in the bath retreating path 20 upstream of the heat exchanger 1. Further, a reheating temperature sensor 24 that detects the temperature of hot water discharged from the heat exchanger 1 is provided in the bath reheating channel 20 on the downstream side of the heat exchanger 1. Furthermore, a water flow sensor 25 that detects a circulation amount of water flowing therethrough is provided in the bath chase path 20.
[0027]
When there is a hot water supply request or a bath renewal request, the control unit 30 configured by a microcomputer or the like based on the temperature and flow rate detected by the various sensors and the set temperature set by the remote controller 31 or the like. However, the gas solenoid valve 5, the gas proportional valve 6 and the like are controlled to control the supply of heat to the heat exchanger 1, and the circulation pump 21 is driven and controlled.
[0028]
For example, in hot water use, when a hot water user opens the hot water tap 16, a water flow having a flow rate of a certain amount or more is generated in the water supply pipe 11. When the flow sensor 13 detects this water flow, the control unit 30 opens the gas solenoid valve 5 in response to a detection signal from the flow sensor 13, that is, a hot water supply request, and the amount of heat necessary for hot water supply at the set temperature is obtained. The opening degree of the gas proportional valve 6 is controlled so as to be supplied, and the amount of gas supplied to the burner 3 is controlled. Thereby, hot water supply of preset temperature is performed.
[0029]
On the other hand, in bathing use, when a bathing switch provided on a remote controller (not shown) is turned on and a bathing request is issued, the circulation pump 21 is driven and water in the bathtub 22 is chased. Circulate through the rolling road 20. Then, the gas electromagnetic valve 5 is opened, the opening of the gas proportional valve 6 is controlled to a predetermined opening, and the gas is supplied to the burner 3. Thereby, bathing is performed.
[0030]
In such a combustion apparatus, in the embodiment of the present invention, the circulation amount is reduced by controlling the driving of the circulation pump 21 so as to keep the circulation amount in the bath reheating channel 20 at a predetermined amount set in advance. To prevent it.
[0031]
FIG. 2 is a diagram showing the relationship between the drive current of the circulation pump 21 and the amount of circulation in the bath reheating channel 20. In FIG. 2, the vertical axis represents the drive current of the circulation pump 21, and the horizontal axis represents the circulation amount. The relationship between the two is obtained, for example, from experiments. According to FIG. 2, the drive current increases as the circulation rate increases. Thus, the circulation amount corresponding to the drive current is obtained from the relationship of FIG. Therefore, the control unit 30 controls the rotation speed of the circulation pump 21 so that the drive current corresponds to the predetermined circulation amount, whereby the circulation amount in the bath reheating path 20 can be made constant. As a result, the ON / OFF temperature in the intermittent combustion control can be set to a high temperature without having to be adjusted to a small circulation amount, so that a high bath retreat capability is ensured.
[0032]
In addition, the circulation amount may decrease even with the same drive current due to an increase in flow path resistance due to secular change such as adhesion of dust to a filter or the like disposed in the bath chase path 20.
[0033]
In such a case, the amount of water is detected by the water amount sensor 25 arranged in the follow-up path 20, and the rotation speed of the circulation pump 21 is controlled so that the detected amount of water becomes constant. At this time, it is preferable to use a DC pump (direct current pump) as the circulation pump 21. This is due to the following reason. In other words, the AC (alternating current) pump that has been used in the past is operated at its maximum efficiency drive voltage during normal operation in order to control its rotation speed, so when the circulation rate decreases, it rotates further. The number does not increase, and the amount of circulation cannot be increased. Moreover, if it becomes below a predetermined rotation speed, the circulation pump 21 will stop and a low-rotation driving | operation cannot be performed. Thus, the AC pump is not suitable for controlling the amount of circulation by controlling the rotation speed.
[0034]
On the other hand, since the rotational speed of the DC pump can be controlled by the switching speed of the electronic control circuit incorporated therein, a desired rotational speed can be obtained by adjusting the switching speed. Therefore, by using a DC pump as the circulation pump 21, it is possible to control the rotation speed of the circulation pump 21 so that the circulation amount becomes constant even when the circulation amount changes.
[0035]
Further, when the clogging of the bath retreating path 20 progresses and cannot be maintained at a predetermined circulation amount even if the rotation speed of the circulation pump 21 is increased, in the embodiment of the present invention, the ON / OFF in the intermittent combustion control is performed. By adjusting the OFF temperature, the water in the hot water supply passage 10 is prevented from boiling.
[0036]
Specifically, the amount of circulation flowing in the bath reheating channel 20 is detected by measuring the drive current of the circulation pump 21 shown in FIG. 2, and the ON / OFF temperature in the intermittent combustion control is detected. It is set according to the amount.
[0037]
FIG. 3 is a diagram showing the relationship between the ON / OFF temperature and the circulation amount for intermittent combustion control. A drive current may be used instead of the circulation amount. In FIG. 3, the vertical axis represents the ON / OFF temperature, and the horizontal axis represents the circulation amount. According to FIG. 3, the ON / OFF temperature is set higher as the circulation amount, that is, the drive current is larger. The greater the amount of circulation, the greater the amount of heat transferred to the bath reheating channel 20 side, and the water temperature in the hot water supply channel 10 is less likely to rise. It is preferable to set it high. At this time, if the predetermined circulation amount is, for example, 10 liters, the default ON / OFF temperature is 89/90 degrees.
[0038]
3 is stored in the storage means of the control unit 30 as a table, for example, and an ON / OFF temperature corresponding to the measured drive current of the circulation pump 21 is selected. Then, the intermittent combustion control based on the selected ON / OFF is performed by the control unit 30. Further, the ON / OFF temperature may be obtained by calculation according to a predetermined calculation formula.
[0039]
FIG. 4 is a diagram illustrating a change in the water temperature in the hot water supply passage 10 when the intermittent combustion control according to the embodiment of the present invention is performed when the circulation amount is different. A line A in FIG. 4 shows a change in water temperature when the ON / OFF temperature in FIG. 3 is set to 89/90 degrees (circulation amount 10 liters), that is, when a predetermined circulation amount is maintained. In this case, since the amount of heat transferred to the bath reheating channel 20 side is large, the water temperature in the hot water supply channel 10 does not rise so much after the combustion is stopped, and even if the OFF temperature is set to 90 degrees, the water temperature does not reach the boiling point.
[0040]
On the other hand, the line B in FIG. 4 shows the case where the ON / OFF temperature in FIG. 3 is set to 84/85 degrees (circulation amount 5 liters), that is, the predetermined circulation amount cannot be maintained and the circulation amount decreases. Shows changes in water temperature. In this case, since the amount of heat transferred to the bath reheating channel 20 side is small, the water temperature in the hot water supply channel 10 increases greatly after the combustion is stopped, but does not reach the boiling point because the ON / OFF temperature is set low.
[0041]
In this way, by setting the ON / OFF temperature according to the circulation amount in the bath reheating channel 20 so that the water in the hot water supply channel 10 does not boil, combustion with a combustion capacity as high as possible according to the circulation amount As a result, the time required for bathing can be shortened.
[0042]
Even if the circulation amount is further reduced, boiling in the hot water supply passage 10 can be prevented by selecting a lower ON / OFF temperature.
[0043]
Further, in the embodiment of the present invention, the circulation pump drive current is used to determine the circulation amount in the bath retreating path 20, but the power consumption of the circulation pump 21 may be used.
[0044]
When the ON / OFF temperature is lowered as the circulation amount is lowered, the bath reheating ability is also lowered accordingly. Therefore, a considerable amount of time is required for the bath chasing time, which makes the user uncomfortable. Therefore, when the circulation amount is below a certain reference amount, for example, it is assumed that some maintenance such as cleaning the filter is necessary, and a warning signal or error signal is output and displayed on the display unit of the remote control 31, for example. It is preferable to call attention to the user.
[0045]
FIG. 5 is a flowchart in the embodiment of the present invention. According to FIG. 5, when a bath retreat request is issued (S1), the circulation pump 21 is driven (S2). Then, the circulation pump 21 is controlled so that the circulation amount becomes a predetermined circulation amount (S3), and the circulation amount is detected by the drive current or the water amount sensor 25 (S4).
[0046]
In step S5, it is determined whether or not the circulation amount is a predetermined amount set in advance. If the predetermined circulation amount can be maintained by the rotational speed control, intermittent combustion control based on a preset default ON / OFF temperature is performed (S9).
[0047]
On the other hand, when the predetermined circulation amount cannot be maintained by the rotational speed control, the ON / OFF temperature corresponding to the circulation amount at the maximum rotational speed of the circulation pump 21 is selected (S8). At this time, it is determined whether or not the circulation amount is less than a certain reference amount (S6). If the circulation amount is less than the reference amount, for example, a warning is displayed on the display unit of the remote controller 31 (S7). Then, intermittent combustion control based on the selected ON / OFF temperature corresponding to the circulation amount is performed (S10).
[0048]
Then, the amount of circulation is monitored while the bath is replenished, and when a bath replenishment stop request is issued (S10), the gas supply to the burner 3 is stopped and the bath replenishment is stopped (S11).
[0049]
By the way, in a combustion apparatus having a bath reheating function that is not limited to a single-can two-channel combustion apparatus, the number of rotations of the circulation pump 21 is controlled as described above, and the circulation amount is kept constant, which will be described below. There is an effect like this.
[0050]
That is, if the circulation amount is constant, the hot water temperature in the bath reheating channel 20 heated by the heat exchanger 1 becomes constant when the supplied heat amount is constant. Accordingly, the temperature of hot water blown out from the circulating metal fittings of the bathtub 22 can be made constant, and a comfortable bath chase can be performed without causing discomfort to the user.
[0051]
Further, in the combustion apparatus that also has a function of pouring water into the bathtub 22, when the amount of remaining water in the bathtub 22 is obtained, first, the circulation pump 21 is driven for a predetermined time to supply a predetermined amount of heat to the heat exchanger 1. Heat the water in the bathtub. Then, the rise degree of the bath water temperature can be detected by the bath water temperature sensor 23, and the remaining water amount can be obtained from the rise degree. That is, if the degree of increase is small, the amount of residual water is large, and if the degree of increase is large, the amount of residual water is small.
[0052]
At this time, it is known that the thermal efficiency of the water heated in the heat exchanger 1 varies depending on the circulation amount. That is, if the circulation amount is large, the thermal efficiency is low, and if the circulation amount is small, the thermal efficiency is high. Therefore, even if the amount of residual water is the same, if the amount of circulation is different, the degree of increase in the bath water temperature changes, and an accurate amount of residual water cannot be obtained. Accordingly, the amount of residual water can be accurately obtained by maintaining the circulation rate constant according to the embodiment of the present invention described above.
[0053]
Further, in the embodiment of the present invention, the DC (direct current) pump is used as the circulation pump 21 instead of the AC (alternating current) pump, thereby providing the following effects.
[0054]
That is, in a single-can two-channel combustion device, when hot water supply and bath reheating are performed at the same time, depending on the type of combustion device, the maximum heat of combustion (maximum number) of the heat exchanger is small. There may be cases where a sufficient amount of heat (number) cannot be obtained simultaneously to carry out the sowing. In such a case, control that gives priority to hot water supply is usually performed. And, for example, when it is necessary to execute hot water supply and bath reheating at the same time as in the combustion apparatus described in JP-A-6-185803, circulation is performed based on the amount of heat necessary for hot water supply (number of hot water supply requests). The bath reheating control is performed by duty-controlling the pump 21 within a range in which the hot water supply request number is maintained.
[0055]
FIG. 6 is a diagram showing the relationship between the number of hot water supply requests and the duty ratio of the circulation pump. The horizontal axis is the number of hot water supply requests, and the vertical axis is the duty ratio of the circulation pump 21. According to Fig.6 (a), the duty ratio of the circulation pump 21 is 100% until the hot water supply request number is 19. However, when the number of hot water supply requests exceeds 19, the duty ratio of the circulation pump 21 gradually decreases to maintain the number of hot water supply requests, and the number of hot water supply requests reaches the maximum number 24. Then, the duty ratio becomes zero and the bath chasing is stopped.
[0056]
At this time, when the AC (alternating current) pump is used as the circulation pump 21, the AC pump cannot operate at a low speed below a predetermined rotation number as described above. As shown in FIG. 6B, duty control becomes impossible.
[0057]
On the other hand, when the DC (direct current) pump is used as the circulation pump 21, the desired rotational speed can be obtained as described above. Therefore, even in the region A that cannot be controlled by the AC pump shown in FIG. The duty control of 21 is performed, and the operation with the maximum number of the combustion apparatus becomes possible.
[0058]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent boiling of the water in the hot water supply channel by controlling the number of rotations of the circulation pump and keeping the circulation amount in the bath reheating channel constant. .
[0059]
Furthermore, even when the circulation amount in the bath retreating path cannot be kept constant, by setting the ON / OFF temperature according to the recirculation amount, the bath retreat with the highest combustion capacity according to the recirculation amount is possible. Since the operation is performed, the time required for bathing can be shortened without causing boiling of water in the hot water supply channel.
[0060]
When the circulation amount decreases and becomes less than a certain reference amount, the user can be informed of the necessity of maintenance by displaying a warning.
[0061]
Furthermore, by keeping the amount of circulation in the bath chasing path constant, the temperature of hot water blown out from the circulation fittings of the bathtub can be made constant, and the amount of remaining water in the bathtub can be accurately obtained. become.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a single-can two-water channel combustion apparatus.
FIG. 2 is a diagram showing the relationship between the drive current of the circulation pump 21 and the amount of circulation in the bath reheating path 20;
FIG. 3 is a diagram showing the relationship between the ON / OFF temperature for intermittent combustion control and the drive current of the circulation pump 21.
FIG. 4 is a diagram showing a change in water temperature in the hot water supply passage 10 when the circulation amount is different.
FIG. 5 is a flowchart of an embodiment of the present invention.
FIG. 6 is a diagram showing the relationship between the number of hot water supply requests and the duty ratio of the circulation pump.
FIG. 7 is a view showing a cross section of the heat exchanger 1 of the single-can two-water channel combustion apparatus.
FIG. 8 is a diagram showing a change in the water temperature in the hot water supply passage 10 when conventional intermittent combustion control is performed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat exchanger 10 Hot-water supply path 17 Heat exchange temperature sensor 20 Bath reheating path 21 Circulation pump 25 Water quantity sensor 30 Control part 31 Remote control

Claims (6)

In the one-can two-water channel combustion apparatus in which the hot water supply channel and the bath retreat channel connected to the bathtub pass through a common heat exchanger,
Temperature detection means for detecting the water temperature in the hot water supply path;
When bath reheating is performed without hot water supply, the temperature detected by the temperature detecting means is set such that the higher the circulation amount of the bath reheating passage, the higher the stop temperature for stopping combustion. Combustion control means for stopping combustion when the temperature exceeds the stop temperature;
A can-two-water channel combustion apparatus comprising: a circulation amount control means for controlling a circulation amount in the bath retreating path so as to maintain a predetermined circulation amount corresponding to the set stop temperature. In claim 1,
When the circulation amount control means cannot maintain the predetermined circulation amount, the combustion control means changes the set stop temperature according to the circulation amount controlled by the circulation amount control means. One can two water channel combustion system. In claim 1,
The circulation amount control means controls a circulation amount in the bath retreating path based on a driving current of a pump that guides and circulates water in the bathtub into the bath retreating path. Combustion system. In claim 1,
Water amount detection means for detecting the amount of water flowing through the bath retreat path is provided, and the circulation amount control means controls the circulation amount in the bath retreat path based on the water amount detected by the water amount detection means. One-can / two-waterway combustion device. In claim 2,
The single-can two-water channel combustion apparatus, wherein an error signal is output when a circulation amount in the bath retreat channel becomes equal to or less than a predetermined reference amount less than the predetermined circulation amount. In claim 3,
The can is a two-channel combustion apparatus characterized by being a direct current pump.

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