JP2562526B2 - Water heater - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating water, which is heated by a heat source, means for detecting water temperature at the inlet side of the heat exchanger for heating water, and means for heating water. Target hot water temperature setting means for setting the target hot water temperature at the outlet side of the heat exchanger, water flow amount detection means for detecting the water flow amount of the water heating heat exchanger, and valve opening degree for changing the water flow amount. Is a water proportional valve configured to be changeable, based on the incoming water temperature detected by the incoming water temperature detecting means, the target hot water temperature set by the target hot water temperature setting means and the maximum heat quantity that the heat source can generate, The outlet water temperature at the outlet side of the water heating heat exchanger determines a target water passage amount for reaching the target outlet water temperature, and the detected water passage amount detected by the water passage amount detection means is equal to the target water passage amount. To be About water heaters in which the control means is provided for changing controlling the valve opening degree of the water proportional valve.

[0002]

2. Description of the Related Art The above water heater uses a water proportional valve to pass water.
Is regulated to the target water flow rate , and the hot water temperature will reach the target temperature .
When the hot water tap connected to the outlet side of the water heating heat exchanger is wide open, for example
Also, so it can maintain a hot water temperature to the target temperature, the eye
The standard water flow is regulated to the maximum water flow by the water proportional valve.
is there. Then, by providing a water flow rate detecting means,
Detects the actual water flow to the heating heat exchanger and
In spite of the change in water flow rate due to the change in water supply pressure,
Be sure to detect the water flow rate of the
Change the valve opening of the water proportional valve to control the hot water temperature.
This ensures that the target temperature can be maintained.
However, the actual water flow rate is detected by the water flow rate detection means.
Therefore, for example, the hot water tap connected to the outlet side of the water heating heat exchanger is opened small and the water flow rate is increased.
When the amount is small, the control means changes the water proportional valve to the valve opening increasing side so that the target water flow rate is simply reached, and as a result, the water proportional valve is fully opened. for that reason,
When the water supply pressure to the water heating heat exchanger is high, temporarily reduce it.
When the opened hot water tap is opened wide and the water flow rate is suddenly changed from a small amount to a large amount , the water ratio in the fully opened state is
For example, an amount of water that is larger than the target water flow rate flows for a while until the valve opens to a predetermined valve opening degree, and there is a disadvantage that the hot water outlet temperature is significantly lower than the target hot water outlet temperature. In other words, the limit to the valve opening increase side of the water proportional valve originally corresponds to the water supply pressure.
However, as mentioned above,
When the person is opened small and then opened wide
In addition, there is a possibility that the above inconvenience may occur.

Therefore, a pressure sensor for detecting the water supply pressure to the water heating heat exchanger is provided to automatically lower the limit value of the water proportional valve toward the valve opening increasing side as the water pressure detection value increases. It may be changed.

[0004]

However, when the pressure sensor is provided, there is a disadvantage that the entire structure is expensive due to the expensive pressure sensor.

The present invention has been made in view of the above circumstances, and an object thereof is to make a target water flow rate proportional to water as much as possible.
Close to the maximum water flow rate of the valve and use the water flow rate detection means.
To detect the actual amount of water passing through and to more reliably target the hot water outlet temperature
Expensive pressure while maintaining the temperature
The point is that the limit value on the valve opening increasing side of the water proportional valve is automatically changed and set according to the water supply pressure without using a sensor or the like.

[0006]

According to a first characteristic configuration of the present invention, a valve opening degree detecting means for detecting a valve opening degree of the water proportional valve is provided, and the control means is adapted to detect the detected water flow rate. Change the valve opening degree of the water proportional valve to the valve opening increasing side by setting the limit value on the valve opening increasing side of the water proportional valve based on the valve opening degree when it becomes equal to the target water flow rate. Is configured to be executed with the limit value as a limit.

The second characteristic configuration is that when the control means makes the target water flow rate corresponding to one target hot water temperature set by the target hot water temperature setting means equal to the detected water flow rate. On the basis of the valve opening degree of the above, it is configured to predict and set a limit value on the valve opening increasing side of the water proportional valve for other target hot water temperatures other than the one target hot water temperature. is there.

[0008]

According to the first characteristic configuration, the control means controls the water flow rate.
The amount of water flow detected by the detection means has become equal to the target amount of water flow.
The valve opening of the water proportional valve is increased based on the valve opening of the water proportional valve at
Set the limit value on the large side, and set the limit value to the water ratio.
An example is to change the valve opening to the valve opening increasing side.
Valve opening of the water proportional valve, such as when installing a water heater.
When it becomes necessary to set a limit value on the increase side,
Open the hot water tap that is connected to the outlet side of the heat exchanger for heating.
As a result, by utilizing the fact that the valve opening when the target water flow rate and the detected water flow rate are equal corresponds to the water supply pressure to the water heating heat exchanger, Based on the detected valve opening, set a limit value on the increasing side of the water proportional valve, and change to the increasing side of the water proportional valve with the limit value as the limit. become.

According to the second characteristic constitution, the control means is provided.
However, based on the valve opening detected when the target water flow rate corresponding to one target hot water temperature and the detected water flow rate are equal, the target hot water temperature other than the one target hot water temperature predicting a limit value of the valve opening increasing side of the water proportional valve will be set, one of the goals in a result
At the tap water temperature, set the limit value on the increasing side of the water proportional valve.
Is set even in case where it is changed to another of different target hot water temperature, since the limit value for the different target hot water temperature is set in advance, variable target hot water temperature is
It is not necessary to reset the setting every time, and the drop of the hot water temperature can be avoided from the beginning.

[0010]

According to the first characteristic configuration, the target water flow rate is
As close as possible to the maximum water flow rate of the water proportional valve, and tap water
Be sure to maintain the temperature at the target temperature more reliably.
Moreover, without using an expensive pressure sensor or the like , it is possible to obtain a water heater that can prevent the tap water temperature from drastically decreasing from the target tap temperature by a simple modification that effectively utilizes the original configuration. .

Further, according to the second characteristic configuration, the limit value on the side of increasing the valve opening degree with respect to each of the target hot water outlet temperatures that are variously changed and set is based on the valve opening degree at one target hot water outlet temperature. Since it is avoided from the beginning that the hot water outlet temperature is lowered when the target hot water outlet temperature is changed to a different target hot water temperature, it can be used more favorably.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a hot water tap 4 is connected via a hot water supply passage 3 to the outlet side of a water heating heat exchanger 2 heated by a gas burner 1 as a heat source, and the water heating heat exchanger 2 is The water supply path 5 connected to the inlet side is provided with a water proportional valve 9 whose valve opening S is changeable in order to change the water flow rate. In addition, the fuel gas supply passage 10 for the gas burner 1 has a gas valve 1 for connecting and disconnecting the fuel gas supply.
1 and an electromagnetic gas amount adjusting valve 12 for adjusting the fuel gas supply amount are attached.

The water proportional valve 9 is equipped with a valve opening sensor 9A as a valve opening detecting means for detecting the valve opening S, and the water supply passage 5 is provided with a valve opening sensor 9A. A water amount sensor 6 as a water amount detecting means for detecting the water amount and a water temperature sensor 7 as a water temperature detecting means for detecting a water temperature Ti at the inlet side of the water heating heat exchanger 2 are provided. A hot water temperature sensor 8 for detecting a hot water temperature Tj is provided on the outlet side of the water heating heat exchanger 2.

Next, the water proportional valve 9 will be described with reference to FIGS. 2 and 3. An outlet 1 for supplying water to the inlet side of the water heating heat exchanger 2 in a tubular valve case 14.
6 and an inflow port 15 for letting in water from a water supply source such as a water supply are formed, and a cylindrical rotary valve body 17 is installed therein. The rotary valve body 17 has the outlet 16
Is formed with a first valve opening 18 which is always communicated with the first valve opening 18 and a second valve opening 18 which communicates the first valve opening 18 with the inlet 15.
A valve opening 19 is formed. Incidentally, the second valve opening 19
Is composed of a large-diameter round hole and a slit-like hole in order to reduce pressure loss at low water pressure. Further, an operation motor 25 for changing the valve opening degree is interlockingly connected to the rotary rod 24 of the rotary valve body 17 via a gear mechanism 23.

The potentiometer-type valve opening sensor 9A for detecting the rotation angle θ of the rotary rod 24 as the valve opening S is attached to the valve case 14.
That is, the rotation angle θ is equivalent to the rotation angle of the rotary valve body 17, and the inflow port 15 is changed according to the change of the rotation angle θ.
The overlapping state of the second valve opening 19 with respect to the above changes, and the valve opening S is changed accordingly (see FIG. 3). Therefore, the correlation between the valve opening S and the rotation angle θ is obtained in advance, and is stored in the control device 13 described later in a relational expression or a numerical table format, so that the valve opening S is changed to the rotation angle. It can be identified by θ.

A control device 13 utilizing a microcomputer is provided, and the detection information of the water amount sensor 6, the incoming water temperature sensor 7, the hot water temperature sensor 8 and the valve opening sensor 9A is input to the control device 13. ing. Then, the control device 13 is configured to operate the gas valve 11, the gas amount adjusting valve 12, and the operation motor 25 according to a command.

A remote controller 20 for instructing operation information to the control device 13 is provided, and an operation switch 21 for instructing start and stop of hot water supply operation and a target hot water outlet temperature To are set in the remote controller 20. An outlet heated water temperature setting device 22 as a target outlet heated water temperature setting means is provided.

Utilizing the controller 13, the incoming water temperature Ti detected by the incoming water temperature sensor 7, the target outgoing hot water temperature To set by the outgoing hot water temperature setting device 22 and the maximum heat quantity Gm which can be generated by the gas burner 1 are controlled. On the basis of,
A target water flow rate Qs for the outlet heated water temperature on the outlet side of the water heating heat exchanger 2 to reach the target heated water outlet temperature To is determined by the following equation (1), and detected by the water amount sensor 6. Control means F is configured to change and control the valve opening S of the water proportional valve 9 so that the water flow rate Qk becomes equal to the target water flow rate Qs. Qs = Gm / (To-Ti) (1) The maximum calorific value Gm is the calorific value when the amount of heat generated by the gas burner 1 is maximized by adjusting the gas amount adjusting valve 12. It is held and stored in advance in the control means F.

The hot water supply operation is started when the controller 13 is powered on and the operation switch 21 is turned on. When the water amount sensor 6 detects the start of water flow due to the opening of the hot water tap 4, the gas valve 11 is opened based on the start of water flow, the gas burner 1 is ignited, and hot water supply is started.

The water proportional valve 9
The valve opening S is controlled so that the detected water flow rate Qk is equal to the target water flow rate Qs as described above, and in parallel therewith, the detected temperature Tj of the hot water temperature sensor 8 and the target hot water temperature To are changed. The opening degree change control of the gas amount adjusting valve 12 is executed so as to be equal. That is, basically, the target hot water outlet temperature To is maintained by adjusting the gas amount adjusting valve 12, and the water proportional valve is used in order to avoid that the water flow amount exceeds the amount capable of maintaining the target hot water outlet temperature To. The valve opening S of 9 is changed. Further, the control device 13, that is, the control means F,
Increase the valve opening of the water proportional valve 9 by setting the limit value SL on the water proportional valve 9 valve opening increasing side based on the valve opening S when the detected water flow Qk becomes equal to the target water flow Qs. The valve opening change to the side is executed with the limit value SL as a limit. The hot water supply control including the valve opening control of the water proportional valve 9 will be described in detail below with reference to the flowchart of FIG.

Initialization processing is executed as the power is turned on. This process also includes a process of initializing the limit value SL of the valve opening degree S at an opening degree of 100% (fully open state).

After the information of the sensors is input, the necessity of hot water supply is determined based on the information of the operation switch 21. If hot water supply is not required, it is determined whether or not hot water is being supplied up to now. It If hot water is being supplied up to now, the fire extinguishing process is executed. In this fire extinguishing process, a process of stopping the operation motor 25 of the water proportional valve 9 is also executed.

When it is determined that hot water supply is required, it is determined whether or not the water amount is less than or equal to the set value based on the detection value of the water amount sensor 6. If the amount of water is less than the set value, it is determined whether or not hot water is currently being supplied. If hot water is being supplied up to now, the fire extinguishing process is executed.

When it is determined in the above determination that the amount of water is equal to or greater than the set value, it is determined whether or not the ignition is being performed. Only when the ignition is not being performed, the gas burner 1 is ignited. The process is executed.

Then, the gas amount control for adjusting the gas amount adjusting valve 12 is executed so as to maintain the target hot water temperature To.

The target water flow rate Qs is calculated by the above equation (1), and the valve opening S is calculated as described above.

Next, it is determined whether the detected water flow rate Qk is equal to the target water flow rate Qs. In this determination, if the difference between the detected water flow rate Qk and the target water flow rate Qs is less than or equal to a predetermined value, it is determined that they are equal. If the detected water flow rate Qk is not equal to the target water flow rate Qs, the water proportional motor control is executed. That is, if the detected water flow rate Qk is larger than the target water flow rate Qs, the water proportional valve 9 is set to reduce the water flow rate.
The operation motor 25 is operated to decrease the valve opening. If the detected water flow rate Qk is smaller than the target water flow rate Qs, the valve opening S and the limit value SL are compared in magnitude, and if the detected water flow rate Qk is smaller than the target water flow rate Qs, the operation motor of the water proportional valve 9 is set to increase the water flow rate as described above. 25 is operated to the valve opening increasing side.

In the above judgment, when the detected water flow rate Qk and the target water flow rate Qs are equal, the valve opening degree S with respect to the target hot water temperature To is based on the target hot water temperature To and the valve opening degree S at that time. The limit value SL is set, and at the same time, the limit value SLn of the valve opening S with respect to another target hot water outlet temperature Ton is predicted and set. In this case, since the detected water flow rate Qk is equal to the target water flow rate Qs, the operation motor 25 is stopped in the water proportional motor control.

[Other Embodiments] In the above embodiment, the limit value SL is set on the assumption that the inflow temperature Ti of the inflow water flowing into the water heating heat exchanger 2 from a water supply source such as a water supply does not change so much. In reality, it is expected that it will fluctuate somewhat. Therefore, after the hot water supply operation for a predetermined time (for example, 1 hour)
It is more preferable to initialize the limit value SL for each time, or to detect the fluctuation of the incoming water temperature Ti and correct the limit value SL accordingly.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

1] Overall configuration of a water heater

[Fig.2] Structure of water proportional valve

FIG. 3 is a graph illustrating a valve opening characteristic of a water proportional valve.

FIG. 4 is a flowchart of hot water supply control

[Explanation of symbols]

 1 Heat Source 2 Heat Exchanger for Water Heating 6 Water Flow Rate Detection Unit 7 Water Input Temperature Detection Unit 9 Water Proportional Valve 9A Valve Opening Level Detection Unit 22 Target Hot Water Temperature Setting Unit F Control Unit Gm Maximum Heat Quantity Qk Detected Water Flow Rate Qs Target Water Flow Rate S Valve opening SL Limit value SLn Limit value Ti Inlet water temperature To Target hot water temperature Ton Target hot water temperature

Claims (2)

(57) [Claims] 1. A water heating heat exchanger (2) heated by a heat source (1), and a water temperature detecting means for detecting a water temperature (Ti) at the inlet side of the water heating heat exchanger (2). (7), a target outlet heated water temperature setting means (22) for setting a target outlet heated water temperature (To) at the outlet side of the water heating heat exchanger (2), and a passage between the water heating heat exchanger (2). Water flow rate detection means (6) for detecting the water flow rate, a water proportional valve (9) whose valve opening (S) is changeable in order to change the water flow rate, and the incoming water temperature detection means (7). Water temperature (Ti) detected by the target hot water temperature setting means (22)
Based on the target hot water temperature (To) and the maximum heat quantity (Gm) that can be generated by the heat source (1), the hot water temperature at the outlet side of the water heating heat exchanger (2) is the target hot water temperature. Target water flow rate (Q) (Q)
s) and the detected water flow rate (Qk) detected by the water flow rate detection means (6) is the target water flow rate (Q).
a water heater provided with a control means (F) for changing and controlling the valve opening (S) of the water proportional valve (9) so as to be equal to s). A valve opening detection means (9A) for detecting the valve opening (S) is provided, and when the control means (F) makes the detected water flow rate (Qk) equal to the target water flow rate (Qs). Limit value (SL) on the valve opening increasing side of the water proportional valve (9) based on the valve opening (S)
Is set to execute the change of the valve opening of the water proportional valve (9) to the valve opening increasing side with the limit value (SL) as a limit. 2. The water heater according to claim 1, wherein the control means (F) corresponds to one target hot water temperature (To) set by the target hot water temperature setting means (22). Based on the valve opening (S) when the target water flow rate (Qs) becomes equal to the detected water flow rate (Qk), a target hot water temperature (To) other than the one target hot water temperature (To) is obtained.
A water heater configured to predict and set a limit value (SLn) on the valve opening increasing side of the water proportional valve (9) for n).