JPH11101506A - Flow regulating valve with overflow preventive function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow-regulating valve with an overflow preventive function enabling the reduction of failures by decreasing the frequency of flow regulating drive. SOLUTION: In a transition period, if actual flow Q is within the range of predetermined first deviation q1 (QS-q1 )<=Q<=QS+q1 ) from target flow QS and continues for a predetermined set time T, it is judged to be in a stable period. In the stable period, when any of a following (1) setting temperature TS is changed, (2) gas capacity is changed and (3) the actual flow Q is out of the range of a second deviation q2 form the target flow QS(QS+q2 >Q>QS-q2 ) by the change of flow of more than the predetermined value, it is judged to be in the transition period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve provided with an overflow prevention function having a function of preventing overflow out of the water heater.

[0002]

2. Description of the Related Art Conventionally, a flow control valve with an overflow prevention function having a function of preventing overflow exceeding a hot water supply capacity of a water heater has a dead zone having a certain width with respect to a target flow rate.
It does not operate for the flow rate within the width of the dead zone, and is always driven for the flow rate outside the width of the dead zone.

[0003]

However, in the above-mentioned conventional flow regulating valve, since the flow outside the dead zone width is constantly driven to adjust the flow, the reading of the flow sensor fluctuates finely and the flow rate is very small. Since the flow rate adjustment driving is performed in response to a change in water pressure, the number of times of driving is extremely increased.

[0004] It is an object of the present invention to provide a flow control valve with an overflow prevention function capable of reducing the number of times of flow control driving and reducing failures.

[0005]

In order to achieve the above object, a flow control valve with an overflow prevention function according to the present invention is provided in a water heater having a flow control valve with an overflow prevention function and a flow sensor. Judges the transition period and the stable period of the control.In the transition period, adjusts the opening of the flow control valve with overflow prevention function so that the actual flow rate matches the target flow rate. By not driving the flow control valve with the overflow prevention function, the actual flow rate Q can be controlled so as to be equal to the target flow rate Qs. The flow control valve with overflow prevention function is not driven, the number of times of driving the flow control valve with overflow prevention function is greatly reduced, and the occurrence of failure of the flow control valve with overflow prevention function 8 can be prevented, and the life can be increased. . In the transition period, the first deviation q ₁ within which the actual flow rate Q is determined in advance from the target flow rate Qs (Qs -q ₁ ≦ Q
≦ Qs + q ₁ ), if it is determined that the period is a stable period when it has continued for a predetermined time T or more, it is possible to easily determine that a transition to the stable period has occurred in the transition period. Further, in the plateau, when the setting temperature Ts is changed, when the gas capacity switching is performed, the actual flow rate Q with a constant or more flow change is out of the range of the target flow rate Qs of the second deviation q ₂ (Qs + Q ₂ >Q> Qs −
q ₂ ), the transition to the transition period can be easily determined in the stable period by determining the transition period when any one of the transient changes occurs.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a water heater to which the present invention is applied will be schematically described with reference to FIG. 2. A water supply pipe 2 is connected to an inlet side of a heat exchanger 1, and a tap water pipe 3 is connected to an outlet side. , A bypass pipe 4 for bypassing the heat exchanger 1 is provided, a water supply (flow rate) sensor 5 and an incoming water temperature thermistor 6 are provided in the water supply pipe 2, and a tap water temperature thermistor 7 and an overflow prevention function are provided in the tapping pipe 3. A flow control valve 8 is provided.

Another example will be described with reference to FIG. 3. The water supply pipe 2 is connected to the inlet of the heat exchanger 1 and the tapping pipe 3 is connected to the outlet thereof. A bypass pipe 4 for bypassing is provided, a water supply (flow rate) sensor 5 and a water inlet temperature thermistor 6 are provided in the water supply pipe 2, a tap water temperature thermistor 7 is provided in the tapping pipe 3, and an overflow prevention function is provided in the bypass pipe 4. An attached flow control valve 8 is provided. In the flow control of the present invention, a transition period such as after ignition of a tapping operation and a scheduled period are determined, and the flow control valve 8 with an overflow prevention function is not operated during a stable period.

The flow control operation of the present invention will be described with reference to the flowchart of FIG. The actual flow rate Q, the target flow rate Qs, and a first deviation q ₁ from the target flow rate Qs (for example, q ₁
= 0.3 l / min.) And the second deviation q ₂ (for example, q ₂ =
1.0 l / min.) (Q ₁ <q ₂ ), and controls the flow control valve 8 with an overflow prevention function so that the actual flow rate Q becomes the target flow rate Qs during a transition period such as after ignition. the actual flow rate Q is first deviation q ₁ within the target flow rate _{Qs (Qs -q 1 ≦ Q ≦} Qs +
q ₁ ), when a predetermined time T (for example, T = 1 second) has been continued for a predetermined time or more, it is determined that a stable period has occurred, and the flow control valve 8 with an overflow prevention function is stopped at the opening at that time. .

When it is determined that the flow is in the stable period and the flow control valve 8 with the overflow prevention function is stopped at the opening at that time, any one of the following transient changes occurs. It is determined that there is. Setting temperature Ts is the actual flow rate Q with a constant or more flow change when the gas capacity switching is performed if the change has deviated from the range of the target flow rate Qs of the second deviation _{q 2 (Qs + q 2>} Q> Q
s -q ₂₎ case

If any one of the above conditions is satisfied, it is determined that a transition has been made to the transition period, and the opening of the flow control valve 8 with an overflow prevention function is controlled so that the actual flow Q becomes the target flow Qs. .

With this configuration, the actual flow rate Q is reduced to the target flow rate Qs
The flow control valve 8 with the overflow prevention function is not driven by the variation in reading of the flow sensor or the minute fluctuation of the water pressure. The number of times of drive is greatly reduced, and the occurrence of failure of the flow control valve 8 with an overflow prevention function can be prevented, and the life can be increased.

[0012]

Since the present invention is constructed as described above, the transition period and the stable period of the flow control are determined, and in the transition period, an overflow prevention function is provided so that the actual flow rate matches the target flow rate. The actual flow rate Q can be controlled to the target flow rate Qs by adjusting the opening of the flow rate control valve and not driving the flow rate control valve with an overflow prevention function until a transient change occurs in a stable period. At the same time, the flow control valve with overflow prevention function will not be driven due to variations in the reading of the flow sensor or small fluctuations in the water pressure, and the number of times the flow control valve with overflow prevention function will be driven will be greatly reduced. It is possible to prevent the occurrence of a failure of the attached flow regulating valve 8 and to prolong its life. In the transition period, the first deviation q ₁ within which the actual flow rate Q is determined in advance from the target flow rate Qs (Qs -q ₁ ≦ Q
≦ Qs + q ₁ ), it is determined that the period is a stable period when the predetermined period of time T or more is continued, so that it is possible to easily determine that a transition to the stable period has occurred in the transition period. Further, in the plateau, when the setting temperature Ts is changed, when the gas capacity switching is performed, the actual flow rate Q with a constant or more flow change is out of the range of the target flow rate Qs of the second deviation q ₂ (Qs + Q ₂ >Q> Qs −
q ₂ ), the transition to the transition period can be easily determined in the stable period by determining the transition period when any one of the transient changes occurs.

[Brief description of the drawings]

FIG. 1 is a flowchart of a flow rate control according to the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a water heater to which the present invention is applied.

FIG. 3 is a schematic configuration diagram showing another example of a water heater to which the present invention is applied.

[Explanation of symbols]

Reference Signs List 1 heat exchanger, 2 water supply pipe, 3 tap water pipe, 4 bypass pipe, 5 water quantity (flow rate) sensor, 6 incoming water temperature thermistor, 7
Hot water temperature thermistor 8 Flow control valve with overflow prevention function

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiichi Tsuji 93, Edocho, Chuo-ku, Kobe-shi, Hyogo Pref.

Claims (3)

[Claims] In a water heater provided with a flow control valve with an overflow prevention function and a flow sensor, a transition period and a stable period of flow control are determined, and in the transition period, the actual flow rate matches the target flow rate. Adjust the opening of the flow control valve with overflow prevention function
A flow control valve with an overflow prevention function, wherein the flow control valve with an overflow prevention function is not driven until a transient change occurs during a stable period. Wherein in the transition period, the first deviation q ₁ within which the actual flow rate Q is determined in advance from the target flow rate Qs (Qs -q ₁ ≦ Q
≦ with Qs + q _1), the over-spill prevention function With flow control valve according to claim 1, wherein determining that a stable period when continuous predetermined set time T or more. In 3. A stable period, deviates from the actual flow rate Q in the range from the target flow rate Qs of the second deviation q ₂ by a certain or more flow rate change when the when the gas capacity switching the set temperature Ts is changed has been performed ( Qs + q _2> Q> Q
_{3. The} flow control valve with an overflow prevention function according to claim 1 or 2, wherein a transition period is determined when any one of the transient changes in s-q2) occurs.