JP2002255298A - Deaeration device, level detector using the device, and combustion machine provided with the detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deaerate from a liquid fuel, which is supplied to a hot-water heater from a fuel tank, to accurately detect a liquid level of the fuel tank by pressure detection in the deaerated condition, to enable detection of remaining fuel in not the fuel tank, but the hot water heater side to detect an amount of remaining fuel by the level detection. SOLUTION: Upon the actuation of a fuel pump 43, a liquid fuel from the fuel tank 7 is sucked into a liquid pump through external piping 81, which is double piping 8, connection portion 41, fuel supply piping 33, and a branch conduit 42. Also, a liquid fuel discharged from the liquid pump 43 is returned to the fuel tank through internal piping 82. A downstream end of the internal piping is disposed so as to project further than the external piping, in order to more entrained air upward into the liquid fuel and separator the air. Pressure of the deaerated liquid is detected by a pressure sensor 9. When the detected pressure decreases by liquid column pressure corresponding to L2 from a reference pressure corresponding to L1 , it is determined that fuel replenishment time has come. Then, a user is informed of the determination result by a remote controller 61. Monitor of an amount of remaining fuel by the air removal and the pressure detection is carried out before combustion by a combustion means 3 or every elapse of predetermined time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing air bubbles (air) mixed in a supplied liquid when the liquid is supplied from a liquid storage tank to a liquid supply destination using the liquid in the storage tank. An air bleeding device capable of supplying a liquid without air mixing to the liquid supply destination, a liquid level detecting device for detecting a liquid level in a storage tank using the air bleeding device, and The present invention relates to a combustion device provided with the air bleeding device when burning at a liquid supply destination as fuel.

[0002]

2. Description of the Related Art Conventionally, there has been known an oil water heater that burns a liquid fuel (oil) such as light oil or kerosene and supplies hot water by using the combustion heat. In this case, usually, an oil water heater is attached to the building, while an oil storage tank for storing oil is installed at a place (for example, outdoors) remote from the oil water heater, and the oil is supplied from the oil storage tank through a fuel supply pipe. Oil is supplied to the combustion part of the water heater. In addition, the replenishment of the oil in the oil storage tank is usually performed by the user replenishing the oil when the residual oil amount is reduced by visual confirmation by the user.

[0003]

By the way, it would be convenient to detect the amount of residual oil in the oil storage tank and notify the user in advance of the oil supply timing.

However, in order to install an oil amount detection sensor for detecting the residual oil amount in the oil storage tank, it is necessary to extend a power line to the oil amount detection sensor, and furthermore, the oil amount detection sensor is required. It is necessary to lay a signal transmission line for acquiring a signal from the building in the building. In particular, when the oil storage tank is installed outdoors, the processing of the extension laying is troublesome. On the other hand, even if the oil amount detection is not performed independently on the oil storage tank side as described above, even if it is linked to the oil water heater to which a power supply line is connected for operation and control of various devices, It is necessary to extend power supply lines and signal transmission lines between the tank and the oil storage tank.

[0005] It is considered possible to avoid such an extension and to detect the residual oil amount in the oil storage tank on the oil water heater side. If the amount of residual oil in the oil storage tank at a remote location can be grasped on the oil water heater side, it is considered that more convenient service can be provided to the user based on the residual oil amount information.

However, in general, the residual oil amount is detected by a method in which the oil level (liquid level) in a certain container is detected by an oil amount detecting sensor and converted into an oil amount based on the detected liquid level. Therefore, if air bubbles (air) are mixed in the oil supplied from the oil storage tank to the oil water heater, the oil amount conversion value will greatly differ from the actual residual oil amount, and the accurate residual oil amount detection Cannot be performed. Further, as a method of detecting the residual oil amount, even if a method of detecting the pressure of oil supplied in a full flow state by a pressure sensor and converting the oil pressure into an oil amount based on the detected pressure is adopted, If air bubbles or air masses are present, the converted oil amount greatly differs from the actual residual oil amount, as described above, so that accurate detection of the residual oil amount cannot be performed.

[0007] On the other hand, if air bubbles are mixed in the oil supplied to the oil water heater, there is also a disadvantage that the combustion itself in the combustion section of the oil water heater becomes unstable.

[0008] The present invention has been made in view of such circumstances, and an object of the present invention is to supply a liquid stored in a storage tank and use the liquid at a liquid supply destination. To provide an air bleeding device capable of reliably supplying a bleeding liquid to a liquid supply destination, and a liquid level detection that can more accurately detect a liquid level in a storage tank using such an air bleeding device. It is an object of the present invention to provide an apparatus and a combustor capable of detecting a liquid level of liquid fuel in a storage tank using such a liquid level detecting device.

[0009]

In order to achieve the above object, according to the invention relating to an air venting device, a liquid supply pipe is provided for supplying an internal liquid from a storage tank for storing a liquid to a liquid supply destination, The following specific items are provided for an air bleeding device for bleeding air contained in the liquid supplied to the liquid supply destination. That is, a return pipe that branches from the middle of the liquid supply pipe and returns to the storage tank, and a liquid pump that causes liquid flowing from the storage tank to the liquid supply pipe to flow back to the storage tank through the return pipe, The downstream end of the pipe is arranged so that the liquid flowing backward by the return pipe is discharged into the stored liquid in the storage tank (claim 1).

According to the first aspect of the invention, the liquid in the storage tank is caused to flow through the liquid supply pipe by the operation of the liquid pump, and the liquid is returned to the storage tank through the return pipe. At this time, since the liquid is discharged into the stored liquid from the downstream end of the return pipe, even if air is mixed in the liquid passing through the liquid supply pipe or the return pipe in the form of bubbles or air masses, the air is stored. The liquid is released into the liquid and rises in the stored liquid due to its buoyancy, whereby the air and the liquid are separated. This makes it possible to reliably supply the liquid to the liquid supply destination through the liquid supply pipe in a state where air has been vented.

In the first aspect of the present invention, at least the downstream side of the return pipe has a double pipe structure together with the liquid supply pipe, and the downstream end of the return pipe is provided in the liquid stored in the storage tank. It can be opened at a position different from the upstream end (claim 2). In this case, in addition to the operation according to the first aspect, since the liquid supply pipe and the return pipe are not separated from each other but are united by a double pipe structure, it is possible to arrange the liquid supply pipe compactly.

In the case of a double pipe structure as described above, a double pipe structure may be used in which the return pipe is an outer pipe and the liquid supply pipe is an inner pipe, or the reverse may be performed as follows. That is, the return pipe is composed of a branch pipe section branched from the liquid supply pipe, and a return pipe section communicating with the branch pipe section and extending to the storage tank, and a circulation pump is provided in the branch pipe section. On the other hand, the return pipe section may be configured as an inner pipe having a double pipe structure in which the liquid supply pipe is an outer pipe. In this case, compactness can be more specifically and easily achieved.

[0013] In any one of the first to third aspects of the present invention, a configuration is provided in which a timer function is further provided and the liquid pump is operated at a time interval equal to or longer than a predetermined set time based on the timer function. (Claim 4). In this case, the liquid in the liquid supply pipe is maintained in a state where the air in the liquid supply pipe is evacuated while eliminating the waste of continuously operating the liquid pump and increasing the efficiency of the operation of the liquid pump in response to the generation or growth of bubbles. Becomes possible.

In any one of the first to third aspects of the present invention, there is further provided an air bleeding instruction means for manually instructing execution of an air bleeding operation, and receiving an instruction from the air bleeding instruction means. It is also possible to adopt a configuration for executing an air bleeding operation by operating the liquid pump (claim 5). In this case, if the user manually operates the air bleeding instruction means, the air bleeding operation is performed, so that the air can be bleed based on the user's intention as needed.

[0015] According to the invention relating to a liquid level detecting device using the air bleeding device according to any one of claims 1 to 5,
And a liquid pressure detecting means for detecting a liquid pressure of a liquid passing through a liquid supply pipe to which a return pipe of the air releasing apparatus is branched and connected, based on the liquid pressure detected by the liquid level detecting means. Thus, the liquid level of the stored liquid in the storage tank to which the upstream end of the liquid supply pipe is connected is detected (claim 6).

According to the liquid level detecting device of the present invention, it is possible to detect the liquid pressure of the liquid from which the air has been removed by the air bleeding device by the liquid pressure detecting means. The liquid level in the storage tank can be detected based on the liquid pressure. In other words, by detecting the liquid pressure while eliminating the influence of the buoyancy caused by the mixed air, the liquid pressure accurately reflecting the liquid column pressure based on the actual liquid level in the storage tank is detected. The liquid level in the storage tank is detected based on This makes it possible to detect the liquid level in the storage tank with higher accuracy than in the case of detecting the pressure of the liquid in the air mixed state,
The remaining amount of liquid in the storage tank can be grasped more accurately.

According to another aspect of the present invention, there is provided a liquid level detecting device using the air bleeding device according to any one of the first to fifth aspects of the present invention. Liquid pressure detecting means disposed in the liquid supply pipe and detecting the liquid pressure of the liquid in the liquid supply pipe,
The liquid level of the stored liquid in the storage tank to which the upstream end of the liquid supply pipe is connected is detected based on the liquid pressure detected by the liquid pressure detecting means after operating the liquid pump of the air bleeding device. (Claim 7).

According to the liquid level detecting device of the seventh aspect, a configuration capable of accurately detecting the liquid level in the storage tank is specified more specifically than the sixth aspect. That is, the liquid flowing into the liquid supply pipe by the operation of the liquid pump is returned to the stored liquid in the storage tank through the return pipe, and when the liquid is returned, the mixed air is separated from the liquid. Since the liquid pressure of the liquid in the liquid supply pipe is detected by the liquid pressure detecting means after the air is removed by separating the mixed air, the liquid level in the storage tank can be detected with high accuracy. The remaining amount of liquid in the tank can be grasped more accurately.

In the liquid level detecting device according to the sixth or seventh aspect, the current liquid level is determined based on a comparison between the reference liquid pressure corresponding to the reference liquid level and the detected liquid pressure detected by the liquid pressure detecting means. A configuration for detecting the position can be adopted (claim 8). In this case, the current liquid level can be accurately detected based on a comparison between the reference liquid pressure acquired in advance and the detected liquid pressure. The “reference liquid pressure” is set in advance as a liquid pressure value detected by a liquid level detection device when the liquid is filled in the storage tank, or a liquid pressure when the liquid is at a liquid level corresponding to the filling. The determined liquid pressure value may be used.

In the liquid level detecting device according to the sixth or seventh aspect, when an increase in the liquid pressure is detected based on the detected liquid pressure detected by the liquid pressure detecting means, the air bleeding device may be used. A configuration in which an air bleeding operation is performed by the operation of the liquid pump may be adopted (claim 9). In this case, by detecting the fluctuation in the increase in the liquid pressure, it is detected that the liquid is supplied to the storage tank and the stored liquid has increased, and in such a case, the liquid pump is operated to release the air. . Then, with the air bleeding performed, the subsequent detection of the liquid level is performed accurately. In other words, since air is likely to be mixed in due to the liquid replenishment described above, by performing air bleeding at the time of the liquid replenishment, the accuracy of the subsequent liquid level detection can be improved.

Further, according to the invention relating to a combustor provided with the liquid level detecting device according to any one of claims 6 to 9,
The apparatus is provided with combustion means for burning liquid fuel in the apparatus, and liquid fuel is supplied from a storage tank for storing liquid fuel provided outside the apparatus to the combustion means through a liquid supply pipe. In order to detect the liquid level of the liquid fuel stored in the apparatus, the liquid level detecting device is attached to the liquid supply pipe at the position inside the apparatus (claim 10).

According to the tenth aspect of the present invention, even when the liquid fuel supplied from the storage tank installed outside the apparatus is burned by the combustion means inside the apparatus, the liquid fuel in the storage tank is burned. The liquid level, that is, the remaining amount of the liquid fuel can be detected by the liquid level detecting device attached to the combustor side. For this reason, it is possible to omit the laying of a power supply line and a signal transmission line necessary for arranging a means for detecting the liquid level in the storage tank outside the machine, and it is also possible to detect the liquid level. Even if the apparatus is laid in the machine away from the storage tank, the liquid level in the storage tank can be accurately detected. In addition, the detected liquid level can be easily obtained on the combustor side, and based on the obtained liquid level, the user can easily determine, for example, the remaining amount of the liquid fuel and the time for replenishing the liquid fuel. Can be notified. In this case, the “combustion machine” can be any combustion machine that burns liquid fuel as fuel.

In the invention of the above-described combustor, in order to provide a combustor for realizing a hot water supply function such as hot water supply to a kitchen, hot water supply to a bathtub, or supply of warm water for heating to a living room, What is necessary is just to provide the hot water supply means which heats water by the combustion heat of a combustion means, and supplies hot water. In this case, each of the hot water supply functions is realized by the hot water supply means.

In the above-described combustor, the detection of the liquid level by the liquid level detecting device can be performed such that the combustion means is executed in a non-combustion operation state (claim 12). ). In this case, it is possible to reliably perform the air bleeding and the liquid level detection without affecting the supply of the liquid fuel to the combustion means.

Further, in the above-described combustor according to claim 10 or 11, the liquid level is detected by the liquid level detecting device when liquid fuel is supplied to the storage tank. (Claim 13). In this case, air is likely to be mixed into the liquid fuel due to the replenishment of the liquid fuel, and when the liquid fuel is replenished, the air bleeding operation by the operation of the liquid pump and the air bleeding operation after the air bleeding operation are performed. By performing the liquid level detection, the subsequent liquid level detection can be accurately performed, and at the same time, a reference liquid pressure serving as a reference for the liquid level detection can be obtained.

Further, in the combustion machine having the hot water supply function according to the eleventh aspect, the detection of the liquid level by the liquid level detecting device is performed at least before the combustion of the combustion means and / or during the preheating period for the hot water supply means. It can be configured (claim 14). Before the combustion, that is, before the first combustion or before the combustion operation of the combustor is reset and before the combustion is performed again, the liquid level is detected by the liquid level detection device to grasp the remaining amount of the liquid fuel fuel in the storage tank. In addition to performing the combustion operation after performing the above, it is possible to reliably perform the combustion operation with the liquid fuel from which the air has been vented. In addition, by detecting the liquid level by the liquid level detecting device during the preheating period of the hot water supply means, during the period when the combustion operation on the combustion means side does not require much accuracy, the liquid level detection for the air bleeding and the liquid level detection is performed. Operation of the device may be performed.

[0027]

As described above, according to the air bleeding device according to the first to fifth aspects, even if air is mixed in the liquid in the liquid supply pipe in the form of bubbles or air masses. Then, the air can be released into the stored liquid to separate the air and the liquid, and the liquid in a state where the air has been removed can be reliably supplied from the storage tank to the liquid supply destination.

In particular, according to the air venting device of the second aspect, the return pipe can be disposed compactly by a double pipe structure with the liquid supply pipe. According to the third aspect, the downsizing can be more specifically and easily achieved. According to the fourth aspect, a state in which the liquid in the liquid supply pipe is reliably ventilated while eliminating waste of continuously operating the liquid pump and increasing the efficiency of the operation of the liquid pump in response to the generation or growth of bubbles. Can be maintained. Further, according to the fifth aspect, the air bleeding instruction means can bleed the air based on the user's intention as needed.

Further, according to the liquid level detecting device according to any one of claims 6 to 9, the air pressure is evacuated by the air bleeding device to detect the liquid pressure while eliminating the influence of buoyancy due to the mixed air. By doing so, the liquid pressure accurately reflecting the liquid column pressure based on the actual liquid level in the storage tank can be detected. Can be detected, and the remaining amount of liquid in the storage tank can be grasped more accurately.

In particular, according to the liquid level detecting device of the present invention, the liquid pressure of the liquid in the liquid supply pipe after the air is reliably evacuated by the operation of the liquid pump can be detected, and the liquid can be stored more accurately. The liquid level in the tank can be detected. According to the liquid level detecting device of the eighth aspect, the current liquid level can be detected more accurately based on a comparison between the reference liquid pressure acquired in advance and the detected liquid pressure.
In addition, according to the ninth aspect, it is possible to reliably remove air that is likely to be caused by liquid replenishment due to liquid replenishment, and it is possible to enhance the accuracy of subsequent liquid level detection.

Further, according to the combustor according to any one of claims 10 to 14, even when the liquid fuel is supplied from the storage tank provided outside the apparatus to the combustion means in the apparatus and burned. In addition, it is possible to omit the laying of the power supply line and the signal transmission line required when arranging the means for detecting the liquid level in the storage tank outside the machine,
The liquid level in the storage tank can be accurately detected even if the liquid level detection device is laid in the machine away from the storage tank. Moreover, the detected liquid level can be easily obtained on the combustor side, and services such as notifying the user of information on the remaining amount of the liquid fuel based on the obtained liquid level can be easily provided. Will be able to

In particular, according to the combustor of the eleventh aspect, there is provided a combustor capable of realizing a hot water supply function such as hot water supply to a kitchen, hot water supply to a bathtub, or supply of hot water for heating to a living room. The above effects can be provided. According to the twelfth aspect of the present invention, the air bleeding and the detection of the liquid level can be reliably performed without affecting the supply of the liquid fuel to the combustion means. According to the combustor of the thirteenth aspect, it is possible to release air from the liquid fuel which is likely to be caused by replenishment of the liquid fuel to the storage tank by the air release operation by the operation of the liquid pump. The liquid level detection after the draining operation can be accurately performed, and the reference liquid pressure serving as the reference for the liquid level detection can also be obtained. According to the combustion device of the fourteenth aspect, the combustion operation can be performed after the remaining amount of the liquid fuel in the storage tank has been ascertained, and the combustion operation can be reliably performed by the liquid fuel that has been vented. Can be done. In addition, by detecting the liquid level by the liquid level detecting device during the preheating period of the hot water supply means, during the period when the combustion operation on the combustion means side does not require much accuracy, the liquid level detection for the air bleeding and the liquid level detection is performed. The operation of the device can be performed.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 shows a hot water heater 1 to which a liquid level detecting device using an air bleeding device according to a first embodiment of the present invention and a combustor provided with the device are applied. The hot water heater 1 includes a so-called semi-hot water storage type heat exchange can 2, combustion means 3 for applying heat of combustion to the heat exchange can 2, and liquid fuel supplied to the combustion means 3. A liquid level detecting device 4 for detecting air bleeding and the remaining amount of liquid fuel, a heating circuit 5 for circulating hot water heat-exchanged by the heat exchange can 2 to various heating terminals (not shown), and a heating operation. And a controller 6 for performing various controls such as the above. Further, a fuel tank 7 as a storage tank for storing liquid fuel (for example, kerosene) burned by the combustion means 3 is installed outside the hot water heater 1. The fuel tank 7 and the fuel tank 7 are provided. And a combustion means 3 as a liquid supply destination to which the liquid fuel is supplied from is connected through combustion supply pipes 81 and 33 described later as liquid supply pipes. The heat exchange can 2 and the heating circuit 5 constitute hot water supply means. Hereinafter, first, the basic components of the hot water heater 1 will be described.

The heat exchange can 2 has a combustion chamber 21 provided with a combustion burner 30 of the combustion means 3 at a lower position.
And a hot water storage room 22 partitioned and formed at the upper position. A large number (for example, more than a dozen) of flue gas passages 23 are extended from the combustion chamber 21 so as to penetrate the hot water storage chamber 22 upward, and are gathered by an exhaust pipe 24 after the penetration. The hot water storage chamber 22 is filled with circulating water. The circulating water is heated to a predetermined temperature by receiving combustion heat from the combustion operation of the combustion burner 30 from the combustion chamber 21 and the combustion exhaust gas passages 23. It has become.

A can body temperature sensor 25 for detecting the temperature of the hot water stored in the internal hot water storage chamber 22 is disposed at an upper position of the heat exchange can 2 and a hot water storage room as a safety device for preventing empty heating at a middle position. A high limit sensor 26 that detects the temperature of the heat exchange can 2 that constitutes 22 is provided. The high limit sensor 26 outputs a command signal for forcibly stopping the combustion of the combustion burner 30 to the controller 6 by detecting a predetermined upper limit temperature. As the circulating water, an antifreeze may be used in a cold region to prevent freezing, and water may be used in other regions.

The combustion burner 30 of the combustion means 3 is constituted by a gun type burner having a return type spray nozzle for burning liquid fuel. The combustion burner 30 is provided with an electromagnetic on-off valve 31 and an electromagnetic supply pump 32. The liquid fuel supplied under pressure through the fuel supply pipe 33 is sprayed and burned. Then, a part of the supplied liquid fuel is returned to the fuel supply pipe 33 between the electromagnetic on-off valve 31 and the electromagnetic supply pump 32 through the return pipe 34.

The return pipe 34 is provided with an oil temperature detection sensor 35 for detecting the oil temperature of the return oil, and a flow control valve 36 for proportionally controlling the flow rate of the return oil. Then, by changing and adjusting the flow rate of the return oil by the flow rate control valve 36, the change and adjustment of the spray amount from the combustion burner 30 is performed, so that the combustion amount of the combustion burner 30 becomes a predetermined value. It is controlled. In FIG. 1, reference numeral 37 denotes an ignition transformer for igniting the oil sprayed from the combustion burner 30, and reference numeral 38 denotes a blower fan for supplying combustion air.

The heating circuit 5 has an upstream end at the hot water storage room 2.
A high-temperature pipe 51, which is connected to the top of the tank 2 and supplies high-temperature water at the top of the hot-water storage chamber 22 to a high-temperature heating terminal (not shown) by the operation of the circulation pump 50, Return pipe 52 returning to the lower part of the hot water storage chamber 22
And a low-temperature outgoing pipe 53 that branches off from the middle of the return pipe 52 and supplies low-temperature water to a low-temperature heating terminal (not shown). The return pipe 52 is provided with an auxiliary tank 54 at an intermediate position above the auxiliary tank 54 and the hot water storage chamber 22.
Are connected to each other by a bypass pipe 56 having a bypass valve 55 interposed therebetween.

The auxiliary tank 54 is of a semi-closed type. A pressure relief valve 57 is mounted on the top of the auxiliary tank 54, and a position before the pressure relief valve 57 is connected to a reserve tank 58. Thereby, when an excessive internal pressure acts on the auxiliary tank 54, the internal warm water is released to the reserve tank 58, and when the reserve tank 58 becomes full, the overflow water overflows from the overflow pipe 58a. Conversely, if the pressure in the auxiliary tank 54 becomes negative,
Air or stored water is returned from the reserve tank 58. A water level detection sensor 59 for detecting the water level in the hot water storage chamber 22 is provided in the auxiliary tank 54.

The operation of the above hot water heater is controlled by a controller 6 having an MPU, a memory, and the like. The controller 6 is connected to a heating remote controller (remote controller) 61 which also functions as an alarm. Through the remote controller 61, the user inputs various commands and performs various status displays. The controller 6 includes a liquid level detection control unit using the liquid level detection device 4 as described later, in addition to a heating control unit that performs a heating operation using the heating circuit 5 and the combustion burner 30.

In the basic heating operation by the heating control unit, the preheating operation is performed by the combustion operation of the combustion burner 30 such that water is supplied into the hot water storage position 22 in advance and the water reaches a predetermined temperature. Then, when the user turns on the heating switch of the remote controller 61, the operation is started, and the circulation pump 50 is operated to circulate the water in the hot water storage chamber 22 through the high-temperature pipe 51, the return pipe 52, and the low-temperature pipe 53. In this state, the combustion operation of the combustion burner 30 is started. When the temperature detected by the can body temperature detection sensor 25 reaches a predetermined set temperature (for example, 60 to 70 ° C.), the combustion amount of the combustion burner 30 is switched so as to maintain the set temperature. When the temperature detected by the can body temperature sensor 25 becomes higher than the set temperature due to a decrease in the amount of heat radiation at the heating terminal as the supply destination, the operation of the electromagnetic supply pump 32 is stopped, and the combustion burner 30 is stopped. Is stopped. When the detected temperature becomes lower than the set temperature due to the stop of the combustion, the combustion operation of the combustion burner 30 is started again. These operations are repeated, and when the heating switch of the remote controller 61 is turned off by the user, both the combustion operation of the combustion burner 30 and the operation of the circulation pump 50 are stopped, and the heating operation is stopped.

The liquid level detecting device 4 attached to the hot water heater 1 having the above basic configuration will be described below.

As shown in FIG. 2, the liquid level detecting device 4 has a connecting portion 41 for connecting the double pipe 8 from the fuel tank 7 and the fuel supply pipe 33 to the combustion means 3, A pressure sensor 9 serving as a liquid pressure detecting means for detecting the liquid pressure of the liquid fuel in the connecting portion 41; a branch pipe portion 42 branching from the fuel supply pipe 33; A liquid pump 43 for causing the liquid fuel to flow back into the fuel tank 7.

The branch pipe section 42 branches from the fuel supply pipe 33 and is connected to the suction side of the liquid pump 43. The upstream pipe section 42a is connected to the discharge side of the liquid pump 43. And a portion 42b. The liquid pump 43 includes, for example, a flexible tube 431 and a rotary cam 43 that is driven to rotate while pressing the flexible tube 431.
The liquid fuel is discharged by continuous extrusion to the downstream pipe section 42b.

The double pipe 8 is composed of an outer pipe 81 and an inner pipe 82. The outer pipe 81 communicates with the fuel supply pipe 33 through the internal space of the connecting portion 41, and the inner pipe 82 is connected to the branch pipe section. 42 is communicated with a downstream pipe section 42b. The upstream end 811 (see FIG. 3) of the outer pipe 81 is connected to the fuel tank 7.
The lower end 821 of the inner tube 82 is opened to project to a position above the upstream end 811 of the outer tube 81 by a predetermined dimension.

As described above, when the liquid pump 43 is operated, the liquid fuel in the fuel tank 7 is caused to flow to the connecting portion 41 through a pipe having a donut-shaped cross section between the outer pipe 81 and the inner pipe 82, and The fuel is supplied from the fuel supply pipe 33 and the branch pipe section 4.
The liquid is sucked into the liquid pump 43 through the second upstream pipe section 42a. The liquid fuel discharged from the liquid pump 43 is returned to the liquid fuel in the fuel tank 7 through the downstream pipe 42b of the branch pipe 42 and the inner pipe 82. If air is mixed in the returned liquid fuel, the air is released into the liquid fuel from the downstream end 821 of the inner pipe 82 based on the buoyancy and subsequently rises and enters the space above the free liquid level. Will be. Thereby, air bleeding is performed.

Accordingly, a liquid supply pipe is constituted by the outer pipe 81 excluding the inner pipe 82 of the double pipe 8 and the fuel supply pipe 33, and a return pipe is constituted by the branch pipe section 42 and the inner pipe 82. The inner pipe 82 constitutes a return pipe section of the return pipe.

In FIG. 1, reference numeral 72 denotes a supply port for liquid fuel to the fuel tank 7, and reference numeral 73 denotes a discharge plug.

The operation of the liquid pump 43 is controlled by the controller 6, and a predetermined notification control is performed by the controller 6 based on the pressure detected by the pressure sensor 9. That is, as shown in FIG. 4, the operation control of the liquid pump 43 and the notification control using the remote controller 61 are performed by the liquid level detection control unit 63 of the controller 6.

Hereinafter, the control by the liquid level detection control unit 63 will be described. First, when the user or the test run operator fills the fuel tank 7 with the liquid fuel,
By turning on the predetermined switch 1, the air bleeding operation and the pressure detection are performed, and the reference liquid pressure is set. That is, after the liquid pump 43 is operated for a predetermined time to bleed air, the liquid pressure detected by the pressure sensor 9 is obtained, and the detected liquid pressure at this time is stored and set as the reference liquid pressure. This reference liquid pressure corresponds to the liquid level L1 (see FIG. 1).

Thereafter, the air bleeding operation and the pressure detection described above are performed at predetermined time intervals based on the timer 64, and the state of drop in the liquid level is monitored. Note that the execution of the air release operation and the pressure detection in this case is prohibited while the combustion signal indicating that the combustion unit 3 is in the combustion state is output from the heating control unit 62.

In addition to the above, when the combustion means 3 is operated by the heating control section 62 based on the ON operation of the heating switch of the remote controller 61, the air bleeding operation and the pressure detection are executed before the combustion. It has become so. The air bleeding operation and the pressure detection may be performed while the heating control unit 62 is performing the preheating operation of the hot water storage tank 22.

When the detected liquid pressure detected by each of the above-described pressure detections becomes lower than the reference liquid pressure by a predetermined amount, notification control is performed. That is, from the reference liquid level L1 to L2 (FIG. 1)
If there is a pressure drop corresponding to only the liquid column pressure (see reference), it is determined that the replenishment time has been reached, and the above-described notification control is started.
Note that L2 may be set in consideration of the allowance from the notification control to the user's replenishment within a range where the downstream end 821 of the inner pipe 81 does not protrude above the free liquid level.

The notification control includes displaying on the display of the remote controller 61 that the replenishment time has come and the need for replenishment in text information or the like, providing voice guidance using a speaker built in the remote controller 61, Or turn on the warning light
It flashes to urge the user to supply. In addition, with or without notification to the remote controller 61, the fuel supply time comes along with the identification information of the hot water heater 1 to a fuel retailer or the like through a communication line connected to the remote controller 61, for example. You may transmit that.

<Second Embodiment> FIG. 5 shows a hot water heater 1 'as a combustor according to a second embodiment. The second embodiment differs from the first embodiment only in that a sub-tank 10 for liquid fuel is provided in the machine, and the other configuration is the same as the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

The sub-tank 10 is interposed between the connection part 41 of the liquid level detecting device 4 and the electromagnetic on-off valve 31 of the combustion means 3. The upstream fuel supply pipe 33 extending from the connection portion 41 by the operation of the second electromagnetic supply pump 11
b, the liquid fuel is supplied to the sub-tank 10, and the operation of the electromagnetic on-off valve 31 and the first electromagnetic supply pump 32 supplies the liquid fuel from the sub-tank 10 to the combustion burner 30 through the downstream fuel supply pipe 33a. .

The operation of the second electromagnetic supply pump 11 is controlled for the sub-tank 10 by the controller 6 based on the detection signal from the float type liquid level detection sensor 12 so as to always maintain a constant liquid level. It has become.

In the hot water heater 1 ′ having such a sub-tank 10, the liquid fuel necessary for the combustion operation by the combustion burner 30 for the time being is secured in the sub-tank 10. The air bleeding operation and the pressure detection can be executed at a more free timing than in the first embodiment. For this reason, it is possible to more finely check whether or not the time to supply the liquid fuel to the fuel tank 7 has come, and it is possible to grasp the arrival of the time to supply the fuel and to perform more accurate notification control accordingly. .

<Other Embodiments> The present invention relates to the first embodiment.
The present invention is not limited to the second embodiment, and includes various other embodiments. That is, in the first and second embodiments, the return pipe is constituted by the branch pipe section 42 and the inner pipe 82, but the branch pipe section 42
May be omitted. In this case, the liquid pump 4
The suction port 3 may be connected to the fuel supply pipe 33 or 33b, and the discharge port of the liquid pump 43 may be connected to the upstream end of the inner pipe 82. Thereby, the connection portion 41
Can also be omitted.

In the first and second embodiments, the inner pipe 82 is used as a part of the return pipe, and the outer pipe 81 is used as a part of the liquid supply pipe. However, the present invention is not limited to this. You may. In this case, the inner pipe of the double pipe 8 communicates with the fuel supply pipe 33 or 33b to form a part of the liquid supply pipe, while the downstream pipe section 42b of the branch pipe section 42 communicates with the outer pipe. Then, the outer pipe may be returned to form a part of the return pipe. Then, as shown in FIG. 6, the downstream end 811 'of the outer pipe 81' penetrates the bottom wall 71 of the fuel tank 7 and projects upward by a predetermined size, while the upstream end 82 'of the inner pipe 82'
1 ′ may be positioned so as to penetrate the peripheral wall of the outer tube 81 ′ and along the vicinity of the bottom wall 71. Thereby, the outer tube 81 '
The air can be separated from the aerated liquid that is returned through.

Further, for example, an air bleeding switch (air bleeding instruction means) is provided on the remote controller 61, and the controller 6 is controlled so that the liquid pump 43 is operated by turning on the air bleeding switch by the user. Is also good. The operation of the liquid pump 43 may be continuously performed, for example, for a preset time, or may be performed only for a time based on the switch operation by the user.

In addition, the controller 6 monitors the fluctuation of the detected pressure from the pressure sensor 9 and, if the detected pressure increases and fluctuates (for example, fluctuates at a predetermined rate or more), the liquid fuel is supplied to the fuel tank 7. It may be determined that the air is released by operating the liquid pump 43 automatically. In this case, the detected pressure detected after air bleeding may be adopted as the reference liquid pressure.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of the liquid level detecting device of FIG.

FIG. 3 is a partially enlarged view of the fuel tank of FIG. 1;

FIG. 4 is a block diagram of a portion related to liquid level detection of a controller.

FIG. 5 is a schematic view showing a second embodiment.

FIG. 6 is a diagram corresponding to FIG. 3, showing another embodiment.

[Explanation of symbols]

1, 1 'hot water heater (combustion machine) 2 heat exchange can (hot water supply means) 3 combustion means (liquid supply destination) 4 liquid level detection device (air release device) 5 heating circuit (hot water supply means) 7 fuel tank (storage) Tank) 8 double pipe 9 pressure sensor (liquid pressure detecting means) 33, 33b fuel supply pipe (liquid supply pipe) 42 branch pipe section (return pipe) 43 liquid pump 63 liquid level detection control section 64 timer 81 outer pipe ( Liquid supply pipe) 82 Inner pipe (return pipe section, return pipe) 81 'Outer pipe (return pipe section, return pipe) 82' Inner pipe (liquid supply pipe) 811 Upstream end of outer pipe (upstream of liquid supply pipe) End) 821 Downstream end of inner pipe (downstream end of return pipe) 811 ′ Downstream end of outer pipe (downstream end of return pipe) 821 ′ Upstream end of inner pipe (upstream end of liquid supply pipe)

Claims (14)

[Claims] 1. A liquid supply pipe for supplying an internal liquid from a storage tank for storing a liquid to a liquid supply destination,
An air bleeding device for bleeding air contained in a liquid supplied to the liquid supply destination, a return pipe branching from the middle of the liquid supply pipe and returning to the storage tank, and a liquid supply pipe from the storage tank A liquid pump for causing the liquid to flow back to the storage tank through the return pipe. The liquid flowing back through the return pipe to the downstream end of the return pipe is discharged into the stored liquid in the storage tank. An air bleeding device, wherein the air bleeding device is disposed in the air vent device. 2. An air release device provided in a liquid supply pipe for supplying an internal liquid from a storage tank for storing a liquid to a liquid supply destination, and for releasing air contained in the liquid supplied to the liquid supply destination. A return pipe that branches off from the middle of the liquid supply pipe and returns to the storage tank; and a liquid pump that causes the liquid flowing from the storage tank to the liquid supply pipeline to flow back to the storage tank through the return pipe. At least the downstream side of the return pipe has a double pipe structure together with the liquid supply pipe, and the downstream end of the return pipe opens at a position different from the upstream end of the liquid supply pipe in the stored liquid in the storage tank. An air bleed device characterized by being performed. 3. The air bleeding device according to claim 2, wherein the return pipe is a branch pipe section branched from the liquid supply pipe.
A return pipe portion communicating with the branch pipe portion and extending to the storage tank; a circulation pump is interposed in the branch pipe portion, and the return pipe portion connects an outer pipe to a liquid supply pipe. An air venting device that constitutes an inner pipe having a double pipe structure. 4. The air venting device according to claim 1, further comprising a timer function, wherein the liquid pump is operated at a time interval equal to or longer than a predetermined time based on the timer function. The air bleeding device is configured as follows. 5. The air bleeding device according to claim 1, further comprising air bleeding instruction means for manually instructing execution of an air bleeding operation, and An air bleeding device configured to perform an air bleeding operation by operating a liquid pump in response to an instruction. 6. A liquid level detecting device using the air bleeding device according to claim 1, wherein the air bleeding device and a return pipe of the air bleeding device are branched and connected. A liquid pressure detecting means for detecting a liquid pressure of the liquid passing through the liquid supply pipe, and a storage in a storage tank to which an upstream end of the liquid supply pipe is connected based on the liquid pressure detected by the liquid level detection means. A liquid level detecting device configured to detect a liquid level of a liquid. 7. A liquid level detecting device using the air bleeding device according to any one of claims 1 to 5, wherein the position of the air bleeding device is smaller than the branch position of the return pipe of the air bleeding device. A liquid pressure detecting means disposed in the liquid supply pipe at the upstream position for detecting a liquid pressure of the liquid in the liquid supply pipe, and the liquid pressure detecting means after operating the liquid pump of the air vent device A liquid level detection device configured to detect a liquid level of a stored liquid in a storage tank to which an upstream end of the liquid supply pipe is connected, based on a liquid pressure detected by the liquid supply line. 8. The liquid level detecting device according to claim 6, wherein a reference liquid pressure corresponding to the reference liquid level is compared with a detected liquid pressure detected by the liquid pressure detecting means. A liquid level detecting device configured to detect a current liquid level. 9. The liquid level detecting device according to claim 6, wherein an air bleeding device is provided when an increase and a change in the liquid pressure are detected based on the detected liquid pressure detected by the liquid pressure detecting means. A liquid level detecting device configured to perform an air bleeding operation by operation of the liquid pump. 10. A combustor provided with the liquid level detecting device according to claim 6, further comprising: a combustion unit for burning liquid fuel inside the unit, and an external unit for the combustion unit. The liquid fuel is supplied from a storage tank for storing the liquid fuel installed in the storage tank through a liquid supply pipe. In order to detect a liquid level of the liquid fuel stored in the storage tank, A combustor comprising the liquid level detection device attached to a liquid supply pipe. 11. A combustion machine provided with a liquid level detection device according to claim 6, wherein a combustion means for burning liquid fuel in the combustion machine, and water generated by combustion heat of the combustion means. A hot water supply means for heating the hot water and supplying hot water to the combustion means. Liquid fuel is supplied from a storage tank for storing liquid fuel provided outside the apparatus to the combustion means through a liquid supply pipe. A liquid level detecting device for detecting the liquid level of the liquid fuel stored in the combustion chamber, wherein the liquid level detecting device is attached to the liquid supply pipe at the inside of the apparatus. 12. The combustion machine according to claim 10, wherein the detection of the liquid level by the liquid level detecting device is performed in a non-combustion operation state of the combustion means. Machine. 13. The combustor according to claim 10, wherein the detection of the liquid level by the liquid level detecting device is performed when the liquid fuel is supplied to the storage tank. Has been, a combustion machine. 14. The combustion machine according to claim 11, wherein the detection of the liquid level by the liquid level detection device is performed at least at the time of initial combustion of the combustion means and / or at the time of preheating the hot water supply means. Have a burner.