JP2845294B2 - Control method of hot water supply heat source device composed of multiple gas instantaneous water heaters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply heat source device used for a central hot water supply device and the like, and more particularly to a method for controlling a hot water supply heat source device comprising a plurality of gas instantaneous water heaters.

[0002]

2. Description of the Related Art In a large or medium-sized building such as a hotel or a general hospital, a central hot water supply system is used to supply hot water to the whole building. Commonly used.

[0003] Such a heat source device is a valuable space because it is difficult to install it on a rooftop which is an empty space because of its weight and space, load and difficulty in construction. It is often installed on floors and basements. Even if the design has sufficient capacity, it is not possible to cope with a case where a large increase in capacity is required, such as when expanding a business, and it is difficult to increase the capacity. Furthermore, such a heat source device is not suitable for mass production, is expensive, and is relatively troublesome to transport and construct.

[0004] In order to solve such a problem,
Recently, attempts have been made to increase the maximum amount of hot water supply by connecting a plurality of gas instantaneous water heaters in parallel and operating them at the same time, and to use the same as a heat source device of a central hot water supply device. In such a heat source device, in order to cope with fluctuations in the hot water supply load, it is necessary to perform control to appropriately increase or decrease the number of instantaneous water heaters operating simultaneously. A remotely operated on-off valve such as a ball valve is provided.
In addition, each of the instantaneous water heaters is of a forced air supply / exhaust type having an air supply fan in view of the hot water supply capacity per required space. The ON / OFF of the instantaneous water heater corresponding to the fluctuation of the hot water supply load is performed by opening and closing the remote control on / off valve by the common control means.

[0005] For example, when the hot water supply load increases, according to the conventional control method, first, as shown in the time chart of FIG. This open command gives
The corresponding on-off valve of the instantaneous water heater is opened.
In this way, the water flow starts, and after the elapse of time t1, at the time when the flow rate sensor detects water flow of a predetermined amount or more, the individual control means provided for each instantaneous water heater knows the operation start command and performs the predetermined sequence. Start the ignition operation.

Therefore, in the instant water heater having an air supply fan, the individual control means uses the detection of the water flow as an ignition start signal when the flow rate sensor detects water flow of a predetermined amount or more, and uses the detected flow as an ignition start signal. The ignition operation is started by turning on the fan and the ignition mechanism. At time t2 after this point in time, when the air volume of the air supply fan reaches a predetermined amount, that is, when the predetermined operation of the air supply fan is detected based on the wind pressure, the rotation speed of the fan motor, and the like, the fuel gas The burner is ignited by opening the valve. Note that the time t1 is the time required for calculating the flow rate by a plurality of pulse counts in addition to the rise time of the flow rate itself due to the characteristics of the motor-operated valve itself, and when the flow rate sensor uses a pulse counting method.

[0007]

Conventionally, since the ignition operation including the start of the air supply fan is started by using the predetermined signal of the flow sensor as the ignition start signal, the common control is performed in response to the increase of the hot water supply load. When the means sends an operation start signal, that is, a command to open the remote control on-off valve, to one of the instantaneous water heaters whose operation is stopped, the burner of the instantaneous water heater burns and the hot water heated by the heat exchanger. It takes a relatively long time until the power is actually supplied, that is, a time t1 + t2 obtained by accumulating the respective rise times. Accordingly, during this time, the water passing through the boiling water path is supplied as it is without being heated, and this water, together with the increase in the hot water supply load, temporarily lowers the temperature of the hot water supplied from the heat source device. An object of the present invention is to solve such a problem.

[0008]

According to the control method of the present invention, in order to solve the above-mentioned problem, the respective boiling paths of a plurality of gas instantaneous water heaters having an air supply fan are connected in parallel. In a heat source device provided with a remote control opening / closing valve in each of the boiling water paths, individual control means for controlling the operation of each of the instantaneous water heaters, and the instantaneous water heater is controlled by the individual control means. The individual control means performs the opening operation of the remote control on / off valve according to a command from the common control means and starts the air supply fan to start a predetermined ignition operation. Then, the supply of the fuel gas to the burner is started on condition that the predetermined operation of the air supply fan is detected.

In the above control method, the individual control means starts the supply of the fuel gas to the burner on condition that the predetermined operation of the air supply fan is detected and the detection of the flow of water equal to or more than a predetermined amount in the boiling water path. Configuration.

In the above control method, the common control means may be configured separately from each individual control means, may be configured in at least one instantaneous water heater together with the individual control means, or may be provided with a plurality of instantaneous water heaters. The individual control means of the water heater can be combined with the communication means.

[0011]

The opening operation of the remote control on-off valve and the start of the air supply fan are simultaneously performed via the individual control means according to the operation start command from the common control means. Therefore, the individual control means
In the case of a configuration in which the supply of the fuel gas to the burner is started on the condition that the predetermined operation of the air supply fan is detected, the time from the operation start command to the start of the supply of the fuel gas to the burner is equal to the supply time. This is the time until the predetermined operation of the air fan is detected, and the time until the passage of a predetermined amount or more of water through the boiling water path is not accumulated.

Also, in the case where the individual control means starts the supply of the fuel gas to the burner on condition that the predetermined operation of the air supply fan is detected and the detection of the flow of water of a predetermined amount or more in the boiling water path is a condition. The time from the start command to the start of the supply of the fuel gas to the burner is the time until the predetermined operation of the air supply fan is detected and the time until a predetermined amount or more of water is detected. Of the times, only the longer time is used, and the shorter time is not accumulated.

The above-mentioned common control means for issuing the operation start command is constituted separately from each individual control means, and is constituted together with the individual control means in at least one instantaneous water heater.
The individual control means of the plurality of instantaneous water heaters can be connected to each other by the communication means.

[0014]

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a system diagram showing an embodiment of an overall configuration of a central hot water supply apparatus having a heat source device to which the control method of the present invention is applied as an element, and the central hot water supply apparatus has a hot water circulation type configuration. I have. Of course, the above heat source device can also be used for a central hot water supply device which is not a hot water supply circulation type.

First, in FIG. 1, reference numeral 1 denotes a circulation pipe passing through a number of hot water supply points 2 (2a, 2b, 2c,...)
The circulation pipe 1 is composed of a hot water supply pipe 3 and a hot water return pipe 4, and a circulation pump 5 is provided at an appropriate location of the circulation pipe 1, for example, as shown in the drawing. A water supply pipe 6 is connected to the hot water return pipe 4. The water supply pipe 6 is configured to be connected to the water supply via a valve 7 and an atmosphere release tank (not shown).

Reference numeral 8 denotes a heat source device.
Are connected in parallel to a plurality of hot water paths 11 passing through respective heat exchangers 10 of a plurality of instantaneous water heaters 9 (9a, 9b, 9c,...), And connected to the hot water paths 11 by remote control such as electric ball valves. An operation opening / closing valve 12 is provided, and the remote operation opening / closing valve 12 is configured to be controlled by individual control means 13 provided for each instantaneous water heater 9 together with control of combustion.

To explain the illustrated components of the instant water heater 9, reference numeral 14 is a burner, 15 is a fuel gas valve, 16 is an air supply fan, 17 is a flow rate sensor, and 18 is a hot water temperature sensor. For the control of the instantaneous water heater 9, an appropriate control method performed in the individual use instantaneous water heater can be applied. For example, the control of the combustion amount of the burner 14 is as follows.
Feedback control is performed using the hot water temperature sensor 18 to control the temperature of the hot water downstream of the heat exchanger 10 to the temperature set in the individual control means 13, and the amount of water measured by the flow rate sensor 18 and the heat exchanger 10 The control can be performed by a feedforward control that controls using a water temperature measured by a water temperature sensor (not shown) provided on the upstream side of the control, a control combining these, a fuzzy control, or the like. In these controls, components such as a proportional control valve for adjusting the amount of fuel gas supplied to the burner 14 and other components necessary for the actual operation of the instantaneous water heater 9, for example, ignition of a spark plug or the like Components such as a mechanism, a frame rod, and a burner safety device such as an empty-fire prevention switch are not shown. The configurations of the three instantaneous water heaters 9 shown in FIG. 1 are all the same, and therefore, reference numerals corresponding to common components are partially omitted.

Reference numeral 19 denotes common control means for controlling the number of operating hot water heaters 9 to control the amount of hot water and the temperature of hot water as a whole. According to the command, the control of the start and stop of the operation of the corresponding instantaneous water heater 9 and the control of the combustion amount are performed. In the operation start operation according to the operation start command from the common control means 19, the individual control means 13
The control for opening the fuel gas valve 15 and starting the supply of the fuel gas to the burner 14 is performed on condition that the predetermined operation is detected. In addition to the detection of the predetermined operation of the air supply fan 16, the control of starting the supply of the fuel gas to the burner 14 may be performed on condition that the water flow of the predetermined amount or more in the water heating path 11 is detected. .

Reference numeral 20 denotes a common hot water supply pipe connected to the hot water supply pipe 3, reference numeral 21 denotes a common water supply pipe connected to the hot water return pipe 4,
Reference numeral 22 denotes a fuel gas common pipe connected to a fuel gas supply source. These common pipes 20, 21 and 22 include a hot water supply connecting pipe 23 to the instantaneous water heater 9, a water supply connecting pipe 24, and a fuel water common pipe. A plurality of sets of gas supply connection pipes 25 are branched, and a manual valve 26 is provided for each of these connection pipes 23, 24, 25. These common pipes 2
Numerals 0, 21 and 22 are configured as units provided with a pipe joint 27 such as a flange joint or a union joint at both ends, and a predetermined number of instantaneous water heaters 9 are provided for each unit.

In the above configuration, when hot water is supplied, the common control means 19 issues an operation start command to the individual control means 13 of the instantaneous water heater 9 at the time of operation. As described above, the number of instantaneous water heaters 9 for sending the operation start command is set according to the hot water supply load, and the selection of the instantaneous water heater 9 to start the operation in this way is made in consideration of the progress of the operation up to that time. It is performed by doing. The hot water supply load is, for example, the flow rate sensor 18 of each instantaneous water heater 9.
Is transmitted from the individual control means 13 to the common control means 19 through the communication means, and the common control means 19 adds and detects the measured values, and detects the temperature of the hot water flowing through the hot water supply pipe 3 with a hot water temperature sensor. It can be detected by monitoring (not shown).

The control operation of the individual control means 13 of the instantaneous water heater 9 receiving the operation start command from the common control means 19 will be described with reference to the time charts shown in FIGS. First, as shown in FIG. 2 and FIG.
In response to the operation start command, the remote control on / off valve 12 is opened, the air supply fan 13 is started, and the ignition mechanism is operated to start the ignition operation in a predetermined sequence.

The remote-controlled on-off valve 12 constituted by an electric ball valve or the like requires a certain amount of time until a predetermined amount of water flows since the flow path is gradually opened. In the case of using a pulse counting method that counts and measures the number of flow pulses per time, it takes a certain amount of time to calculate the flow rate by a plurality of pulse counts.
It takes a rise time t1 as shown in FIG. 4 until a predetermined amount of water is detected from the signal from the flow rate sensor 17. On the other hand, due to the inertia of the air supply fan 13 itself and the drive motor (not shown), it takes some time from the start to the time when a predetermined air volume is obtained. Air supply fan 16 by motor tachometer, etc.
It takes a rise time t2 until the predetermined operation is detected.
In the figure, for the sake of convenience, the rise time t1 of the amount of water is shown to be longer than the rise time t2 of the air supply fan 16, but these rise times are longer or shorter in actual equipment. May be reversed or substantially equal.

In the control shown in FIG. 2, when the rise time t2 elapses and the predetermined operation of the air supply fan 16 is detected, the individual control means 13 controls the fuel supply regardless of the signal of the flow rate sensor 17. The gas valve is opened to perform ignition by the ignition mechanism in the operating state. Further, in the control of FIG. 3, ignition is not performed only when the rising time t2 has elapsed, and ignition is performed when the rising time t1 has elapsed and both the air volume and the water volume are satisfied. That is, the ignition is performed when the rise time on the long side has elapsed.

Therefore, in the former control, the time from the start of the operation to the start of the supply of the fuel gas to the burner 14 is the time until the predetermined operation of the air supply fan 16 is detected. In other words, the rise time t2 is reached, and the hot water path 11
Is not accumulated until the flow of water equal to or more than the predetermined amount is detected, that is, the rise time t1. On the other hand, in the latter control, the time from the operation start command to the start of the supply of the fuel gas to the burner 14 is the longer one of the rise times t1 and t2, that is, as shown in FIG. When t1> t2, only the rise time t1 is obtained, and the rise time t2 is not accumulated.

As described above, in the former control, the hot water path 11
Since the detection of water passing over a predetermined amount is not used as the above-mentioned ignition condition, ignition is performed earlier as compared with the latter control.However, in this control, safety when water does not flow at the time of ignition is Measures are needed.

As such a safety measure, there is a method in which control is performed by adding the detection of a predetermined amount or more of water at a time when a predetermined time has elapsed from the ignition time. After the lapse of time, if the flow of water equal to or more than the predetermined amount is not detected, the fuel gas valve 15 is closed and the burner 1 is closed.
4 is extinguished, and then control is performed to re-ignite if a predetermined amount or more of water flow is detected. As another method, the temperature of the hot water from the heat exchanger 10 is monitored by the hot water temperature sensor 18,
When the temperature of the hot water is higher than a predetermined temperature, there are a method of extinguishing the burner 14 or continuing the combustion with a low capacity, a method of using a conventional dry-burn prevention switch and the like.

In the central hot water supply apparatus constituted by the heat source device 8 described above, the return hot water flowing through the hot water return pipe 4 by the circulation pump 5 joins with the clean water supplied from the water supply pipe 6 to supply hot water. The water flows into the common water supply pipe 21 from the return pipe 4. And the instantaneous water heater 9 during operation from the water supply connection pipe 24.
Flows into the water input side of each of the hot water paths 11 and
After being heated through 0, it joins the hot water supply common pipe 20 corresponding to the hot water supply pipe 3 from the hot water supply connection pipe 23. The combined hot water flows from the hot water supply common pipe 20 through the hot water supply pipe 3 to reach the hot water supply point 2, where a part of the hot water is used. The remainder is returned to the hot water return pipe 4, merges with the clean water supplied from the water supply pipe 6 according to the amount of hot water used, and returns to the above-described instantaneous water heater 9.
For circulation through the heat exchanger 10.

In the above operation, the amount of hot water used increases,
That is, when the hot water supply load increases, the common control means 1
9 sends an operation start command to the individual control means 13 of the appropriate number of instantaneous water heaters 9 in operation, in addition to the instantaneous water heater 9 currently in operation, and sets the corresponding instantaneous water heater 9 as described above. Start operation according to the procedure. In this way, an appropriate number of instantaneous water heaters 9 are added to the currently operating instantaneous water heaters 9 to be in an operating state, so that the overall hot water supply capacity is increased, and the above-described increase in load is dealt with. can do. Conversely, when the amount of hot water decreases and the hot water supply load decreases, the common control means 19 selects an appropriate number of the instantaneous water heaters 9 currently in operation and sends an operation stop command to the individual control means 13. Then, the operation of the selected instantaneous water heater 9 is stopped. Thus, the instantaneous water heater 9 in the operating state
Is reduced, it is possible to cope with a decrease in hot water supply load. Instantaneous water heater 9 to increase or decrease in the above operation
And the like can be set as appropriate, and for example, a method of increasing or decreasing the number step by step can be adopted.

The common control means 19 which performs the above-mentioned functions.
Can be configured separately from each individual control means 13, be configured with at least one instantaneous water heater together with the individual control means 13, or be provided with the individual control means 13 of a plurality of instantaneous water heaters by a communication means. They can be combined and configured.

In the above-mentioned central hot water supply device, for example, when the required hot water supply amount is greatly increased due to business expansion or the like, and even if all of the existing instantaneous water heaters 9 of the heat source device 8 cannot be operated, it cannot be handled. By adding an appropriate number of other instantaneous water heaters in addition to the existing instantaneous water heater 9, the maximum hot water supply capacity can be easily increased. In the above-mentioned use, if any of the instantaneous water heaters 9 fails, it is only necessary to repair or replace them alone. This repair or replacement is performed by the manual valve 26 provided in each connection pipe 23, 24, 25. Is closed, it is possible to easily perform repair or replacement in the operating state of the other instantaneous water heater 9, that is, in a state of supplying hot water.

[0031]

As described above, according to the present invention, a plurality of gas instantaneous water heaters having an air supply fan are connected in parallel to each other, and the number of operating units can be controlled by common control means. In the configured heat source device, when starting the operation of the instantaneous water heater corresponding to the increase of the hot water supply load, the operation of opening the remote control on-off valve and starting the air supply fan from the common control means to the individual control means are performed. Since the start command is performed at the same time, the rise time of each of the remote control on-off valve and the supply fan is not accumulated. Therefore, compared with the conventional control method in which these are accumulated, the operation start command is issued. It is possible to shorten the time from when the command is issued to when the fuel gas valve opening command is issued, and thus it is possible to prevent a temporary decrease in the temperature of the hot water supplied from the heat source device.

[Brief description of the drawings]

FIG. 1 is a system explanatory diagram showing an example of a central hot water supply device using a heat source device to which a control method of the present invention is applied.

FIG. 2 is a time chart showing an operation of one control method of the present invention.

FIG. 3 is a time chart showing an operation of another control method of the present invention.

FIG. 4 is a time chart showing an operation of a conventional control method.

[Description of Signs] 1 Circulation type pipe 2 Hot water supply point 3 Hot water supply pipe 4 Hot water return pipe 5 Circulation pump 6 Water supply pipe 7 Valve 8 Heat source device 9 Instantaneous water heater 10 Heat exchanger 11 Water heater path 12 Remote control opening and closing valve 13 Individual control means 14 Burner 15 Fuel gas valve 16 Air supply fan 17 Flow rate sensor 18 Hot water temperature sensor 19 Common control means 20 Common hot water supply pipe 21 Common water supply pipe 22 Common fuel gas pipe 23 Hot water supply connection pipe 24 Water supply connection pipe 25 Fuel Connection pipe for gas supply 26 Manual valve 27 Fitting

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Nishi 201 Nishikashiwara Nitta, Fuji City, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (72) Inventor Takao Takagi 201 Nishi Kashiwara Nitta 201 Fuji, Shizuoka Prefecture Takagi Sangyo Stock In-house (72) Inventor Kimio Mochizuki 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (72) Inventor Yokozo Shinohara 201 Nishi-Kashiwara Nitta 201, Fuji City, Shizuoka Prefecture Takagi Sangyo Co., Ltd. (72) Inventor Shusuke Hashimoto 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (72) Inventor Hidetada Takada 201 Nishi Kashiwara Nitta 201 Fuji, Shizuoka Prefecture Inside Takagi Sangyo Co., Ltd. (56) References JP 1-247946 (JP, A) JP-A-4-203837 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24H 1/10 301

Claims (5)

(57) [Claims] 1. A heat source device in which a plurality of gas instantaneous water heaters having an air supply fan are connected in parallel to respective boiling paths and provided with a remote control on / off valve in each of the boiling paths.
Individual control means for controlling the operation of each instantaneous water heater, and common control means for controlling the number of operating instantaneous water heaters by control via the individual control means, wherein the individual control means are common In response to a command from the control means, the remote control on / off valve is opened, the air supply fan is started to start a predetermined ignition operation, and the fuel gas to the burner is detected on condition that the predetermined operation of the air supply fan is detected. Control method for hot water supply heat source device comprising a plurality of gas instantaneous water heaters, characterized by starting supply of water 2. The control method according to claim 1, wherein the individual control means detects the predetermined operation of the air supply fan and detects the flow of the fuel gas to the burner at a predetermined amount or more in the boiling water path. Control method for hot water supply heat source device comprising a plurality of gas instantaneous water heaters, characterized in that supply of water is started 3. A hot water supply system comprising a plurality of gas instantaneous water heaters according to claim 1 or 2, wherein the common control means is provided separately from each individual control means. Control method of heat source device 4. The control method according to claim 1, wherein the common control means is constituted by a plurality of gas instantaneous water heaters, wherein at least one instantaneous water heater is constituted together with individual control means. Of controlling hot water supply heat source device 5. The control method according to claim 1, wherein the common control means is constituted by connecting individual control means of the plurality of instantaneous water heaters by communication means. Control method of hot water supply heat source device composed of instantaneous water heater