JPH01150746A - Water amount control device for hot water feeder - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a seizure accident due to the overload state of a motor occasioned by fixing of a water amount control valve, by a method wherein, through the motion of a water amount control valve in which, when a heat demand load exceeding maximum capacity is present, a water amount control valve is throttled, and when it is below the maximum capacity, the opening of the water amount control valve is increased, a limit time is set for drive in the same direction. CONSTITUTION:Heating capacity QG of a hot water feeder is divided by a difference between a set temperature TS and an inflow water temperature Ti in a step P1 to determine a capacity water amount FLmax, and a difference between FLmax and a feed water amount FL and a deviation water amount DELTAfL in a step P2. In a step P3, if DELTAfL is in a specified value, a drive motor 11 of a water amount control valve 10 is stopped in a step P4. If it is outside a specified value, in a step P5, a motor drive limit timer is set according to a code of DELTAfL, when a code is (-), the motor drive limit timer is set in a step P6. In a step P7, the control valve 10 is throttled, and if it is within a specified value in a step P3, the drive motor 11 of the control valve 10 is stopped in a step P4. If the control valve 10 is in a fixed state, a timer in a step P6 is time-up, and the motor 11 is stopped in a step P9. Meanwhile, if a code is (+), a timer is set in a step P11 so that the opening of the control valve 10 is increased, and at the same time when a valve opening signal is outputted in a step P12, a valve opening motion time is limited.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a water flow control device for controlling the flow of hot water from a gas instantaneous water heater or the like.

BACKGROUND OF THE INVENTION Conventional control devices of this type include a fuel control valve (for example, a gas proportional control valve) that adjusts the amount of combustion so that the hot water temperature reaches a set temperature.

In addition, if a heat load that exceeds the maximum capacity of the water heater is required, the temperature of the hot water that comes out will drop, so in order to prevent this, the water supply amount will be automatically reduced if there is a heat load request that exceeds the maximum capacity. A water flow control valve is provided. These water flow control valves are generally driven by a DC motor, and the opening degree of the water flow control valve is adjusted by a water flow sensor, timer, etc.
Publication No. 62-40624, Utility Model Publication No. 1988-40624
120154).

Problems to be Solved by the Invention However, with the above configuration, there is a problem in that when foreign matter gets into the water flow control valve, the motor that drives the water flow control valve becomes locked and burnt out.

The present invention solves such conventional problems and aims to limit the operating time of the water flow control valve.

Means for Solving the Problems In order to solve the above problems, the water flow control device of the present invention is configured to set a time limit for driving the water flow when there is a heat demand load exceeding the maximum capacity.

Effect of the Invention With the above-described configuration, the present invention can prevent burnout accidents caused by motor overload conditions due to sticking of the water flow control valve or the like.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 1 is a control system diagram of a water heater that is an embodiment of the present invention, in which 1 is a heat exchanger, and 2 is a burner that heats the heat exchanger 1. Hot water is heated through a hot water supply cylinder 3. Ru. 4 is a hot water temperature detector that detects the temperature of hot water heated by the heat exchanger 1; 6 is a fuel regulator that adjusts the amount of gas supplied to the burner 2; 6 is a temperature setting device; and 7 is a combustion amount control means. The temperature detected by the hot water temperature detector 4 is fed back to control the fuel regulator 6 so that the temperature is set by the temperature setting device 6. The combustion amount control means 7 is a general proportional one.

It consists of PID feedback control of integral and differential control. 8 is an inlet water temperature detector that detects the temperature of water supplied to the heat exchanger 1; 9 is a water amount detector that detects the amount of water supplied; 1o is a water amount control valve that controls the amount of water supplied; the valve opening direction is controlled by the drive motor 11; and the throttle direction drives the valve in the valve closing direction. Reference numeral 12 denotes water flow control means for controlling the water flow control valve 1o, which executes the control contents shown in FIG. FIG. 2 shows an operation flowchart when the system is configured with a microcomputer or the like.

In FIG. 2, in step P1, the capacity water amount FLma is determined from the set temperature Ts set by the temperature setting device 6, the inlet water temperature T1 detected by the inlet water temperature detector 8, and the heating capacity QG of the water heater.
Find x using the formula below.

FLmax = QG/Ts - Ti In step P2, the capacity water amount FL m! The deviation water amount ΔfL between LX and the water supply amount FL detected by the water amount detector 9 is determined. That is, Δf L = FLma
x FL.

In step P5, if the ΔfL is within the specified range, for example within ±11, the energization to the motor 11 that drives the water flow control valve 10 is stopped in step P4. If ΔfL is greater than or equal to the specified value, the opening/closing direction of the water flow control valve 1o is determined in accordance with the sign of Δf in step P5.

That is, when the sign of ΔfL is e, F Lmax < F
In the state L, the water supply amount exceeds the capacity water amount, so set the motor drive limit timer with knob P6 and step P7.
, outputs a valve close signal to throttle the water flow control valve 1o. The water amount control valve 1o reduces the amount of water flowing into the heat exchanger 1 and controls it to the capacity water i F L max value.

Then, in step P3, if the deviation water amount ΔfL falls within the above-mentioned regulation, for example, within ±11, the water flow control valve 10
energization to the motor 11 that drives the water volume control is terminated. At this time, if foreign matter has entered the water flow control valve 1o and it is stuck, the motor 11 will be overloaded and the conditions in step P3 will not be satisfied and the motor drive limit timer in step P6 will time out. Proceeding to step P8, an operation error of the water flow control valve is set, and energization to the motor 11 is stopped in step P9. Thereafter, in step PjO, energization to the motor 11 is prohibited due to branching due to the water flow control valve error.

The motor drive limit timer is set according to the operating characteristics of the water flow control valve.

On the other hand, if the sign of the deviation water amount ΔfL is ■ in step P5, the water flow control valve 1 is closed in a state where FLmax < FL and the water supply amount FL is smaller than the capacity water flow F L 1112LX value.
In order to increase the opening degree of ゜, set the motor limit timer in step Pj+ in the same way as when the capacity water amount is exceeded.
At step Pi2, a valve opening signal is output and at the same time the valve opening operation time is limited.

In step Pj3, the water amount control operation described above is executed only when the water heater is burning.

In the above configuration, the water flow control valve 10 has the function of time-limiting the same control action in the control action of the water flow control valve.
This has the effect of preventing the device from being used in a faulty state.

Effects of the Invention As described above, according to the water flow rate control device for a water heater of the present invention,
The following effects can be obtained.

(1) By setting a time limit for the opening and throttling operations of the water flow control valve, overload burnout of the motor due to sticking of the water flow control valve can be prevented.

(2) When there is a heat load request that exceeds the maximum capacity of the water heater, the amount of water supplied is reduced to the capacity water amount, so the drop in hot water temperature can be shortened and hot water can be poured at the set temperature.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram of a water flow control device for a water heater according to the present invention;
FIG. 2 is an operational flowchart of the water flow control means. 1...Heat exchanger, 2...Burner, 7.
... Combustion amount control means, 1o ... Water amount control valve, 12 ... Water amount control means.

Claims (1)

[Claims] a heat exchanger, a burner that heats the heat exchanger, a combustion amount control means that detects the outlet temperature of the heat exchanger and adjusts the combustion amount to obtain a set temperature; When there is a heat demand load that exceeds the maximum capacity of the provided water flow control valve and the combustion amount control means that does not reach the set temperature, the water flow control valve is throttled to the capacity water flow, and the water flow control valve is opened and closed. A water flow control device for a water heater, comprising: a water flow control means that sets a time limit for controlling the water in the same direction.