JPH01302063A - Water quantity controller for hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To supply hot water near a set temperature even at the time of the start of the supply of hot water by controlling the opening of water quantity regulating means to a smaller value than a decision opening at the time of the start of the supply of the hot water, and gradually altering it to the decision opening on th basis of the detection temperature of temperature detecting means. CONSTITUTION:An opening limiter 47 is provided in a water quantity controller 44 to so limit an opening as to control a water quantity control valve 34 an initial hot water supply opening VO1 smaller than an opening VOn responsive to a set temperature determined by opening decision unit 46 at the time of the start of the supply of hot water. The limited opening VO1 is 85% of the opening VOn. It is increased only by 5% when the supplied hot water temperature from a heat exchanger 32 by a detection signal from a supplied hot water temperature thermistor 38 becomes a set hot water temperature, and thereafter sequentially increased by 5%. Thus, sufficiently heated hot water to be supplied is obtained even at the initial time of the supply of the hot water in which the thermal capacity of the exchanger 32 is small. Since the limit of the opening is immediately alleviated in a reoperation in which sufficient thermal capacity is provided, the supplied hot water temperature does not become excessively high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water flow rate control device for a water heater in which the opening degree of a water valve is controlled according to a set hot water temperature.

[Prior art] Water heaters that automatically start supplying and heating hot water when operating a switch, etc. do not only change the heating amount such as the amount of combustion (but also change the temperature of hot water output by controlling the amount of water supplied). To achieve this, the opening degree of a water valve such as a water flow control valve is adjusted to supply hot water at a water temperature that corresponds to the set temperature. Based on the temperature difference between the temperature of the hot water and the set hot water temperature, and the heating capacity of the burner that heats the heat exchanger, it is uniquely determined so that an appropriate opening degree can be obtained during steady operation.

[Problems to be Solved by the Invention] Therefore, at the start of water supply when the heat exchanger is not sufficiently heated by the heating means, the heat capacity of the heat exchanger is small and the temperature of the water supplied tends to be lower than the set temperature. There is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a water flow rate control device for a water heater that can supply hot water close to a set temperature even at the start of hot water supply.

[Means for Solving the Problems] The present invention detects the inflow of water into a heat exchanger for heating water, starts heating the heating means for heating the heat exchanger, and starts heating the heating means for heating the heat exchanger. A water flow rate control device for a water heater that determines the opening degree of a water flow rate adjusting means that adjusts the flow rate of water flowing into the heat exchanger based on heating capacity, the flow rate of water flowing into the heat exchanger, and the temperature of the water flowing into the heat exchanger. A temperature detecting means is provided for detecting the temperature of hot water flowing out of the container, and when starting hot water supply, the opening degree of the water amount adjusting means is controlled to be smaller than the determined opening degree, and the temperature is detected by the temperature detecting means. The technical means is to gradually change the opening degree of the water amount regulating means to a determined opening degree based on the temperature.

[Function] In the present invention, the opening degree of the water amount regulating means is set such that at the start of hot water supply,
Since the opening is controlled to be smaller than the determined opening, the amount of hot water supplied is reduced. Therefore, the heating amount of the heating means will act on a small amount of water, and even if the heat capacity of the heat exchanger etc. is insufficient, the relative heating amount that will act on the water being supplied will be large. , can be heated to a water temperature close to the set water temperature. After that, the heat capacity of heat exchangers etc. increased,
When the temperature of the water detected by the temperature detection means rises, the opening degree of the water amount adjustment means is controlled to a gradually determined opening degree.

[Effects of the invention] In the present invention, at the start of hot water supply when the heat capacity of the heat exchanger is small, the amount of water is reduced and the relative amount of heating is increased, so the temperature of the hot water flowing out from the heat exchanger is brought closer to the set water temperature. After that, the opening degree of the water amount control means is gradually changed, so hot water can be continuously supplied at the set hot water temperature. Also, at this time, the opening degree of the water flow control means is changed based on the temperature detected by the temperature detection means.
The hot water temperature does not become too high.

[Example code] Next, the present invention will be explained based on embodiments shown in the drawings.

The gas water heater of this embodiment, which is schematically shown in FIG. 2, has a combustor 1
0, a fuel pipe 20, a water pipe 3o, and a control circuit 40.

The combustor 1o consists of a burner group 11 provided in the water heater case 1 and a blower 12 that supplies combustion air, and burns the fuel gas supplied from the nozzle 13 with the combustion air supplied by the blower 8112. The combustion gas is discharged from the exhaust port 2.

The burner group 11 is a two-bar burner with a plurality of ribbon burners arranged in two rows, and above near the burner group 11 are a sparker 14 of an ignition device, a flame rod 15 for flame detection, and a thermostat. Each couple 16 is provided.

The fuel pipe 20 is a gas pipe that supplies fuel gas to the nozzle 13, and includes, in order from the upstream side, a main solenoid valve 21, a main solenoid valve 22, and a proportional valve 23 that adjusts the amount of fuel supplied to the burner group 11. At the downstream of the proportional valve 23, the fuel pipe 2o is branched to supply fuel gas to each set of two burners, and one of the branched fuel pipes 20 is connected to one of the burner groups 11. In order to burn only one series,
A solenoid valve 24 is provided.

The water pipe 30 includes a supply pipe 31 and a hot water supply pipe 31a connected to a water supply source and a hot water supply port (not shown), respectively, and a heat exchanger 32 and a bypass pipe 3 provided to communicate these.
2a, a part of the water supplied from the supply pipe 31 is led to the hot water supply pipe 31a via the heat exchanger 32, and the remaining part is led to the hot water supply pipe 31a via the bypass pipe 32a. A bypass valve 33 is provided at the merging section on the side, and mixes the water heated by the heat exchanger 32 and the water directly guided through the bypass pipe 32a by appropriately adjusting the proportion thereof.

On the other hand, a water flow control valve 34, a water flow sensor 35, and an inlet water temperature thermistor 36 are installed in the supply pipe 31 from the upstream side, a heat exchange thermistor 37 is installed downstream of the heat exchanger 32, and an outlet water temperature thermistor 38 is installed in the hot water supply pipe 31a. are provided for each.

The control circuit 40 controls the operating state of the water heater mainly using a microcomputer, and includes a sequence control section 4.
1. Heating control section 42, combustion control section 43, water amount control section 44
It consists of each functional section.

The sequence control unit 41 controls other functional units to start combustion in a predetermined sequence when the operation switch 45a of the controller 45 operated by the user is turned on, and when the combustion state and hot water supply state reach predetermined conditions. Stop combustion.

The heating control unit 42 controls the water temperature set by the hot water temperature setting switch 45b provided in the controller 45, and the water flow sensor 35.
, the required heating amount is calculated based on the signals from the inlet water temperature thermistor 36, the heat exchange thermistor 37, and the outlet water temperature thermistor 38, and the combustion control section 43 and the water amount control section 44 are controlled.

The combustion control unit 43 controls the blower 12 , the proportional valve 23 , and the solenoid valve 24 in accordance with the control of the heating control unit 42 to cause the combustor 10 to burn at the required combustion amount, and also to respond to the signal from the thermocouple 16 . The air-fuel ratio is corrected based on this.

The water amount control unit 44 is controlled by the heating control unit 42 to
The opening degree determining unit 46 determines the opening degrees of the bypass valve 33 and the water flow control valve 34, adjusts the amount of water passing through the heat exchanger 32 and the bypass pipe 32a, and adjusts the temperature of the hot water supply to the set temperature.

In particular, in controlling the water flow control valve 34, the opening determining section 46
An opening degree limiting section 47 is provided to limit the opening degree determined by the opening degree determining section 47 as shown in FIG.
The opening degree is limited so that the water flow control valve 34 is controlled to the opening degree V01 for initial hot water supply, which is smaller than the opening degree VOn corresponding to the set temperature determined in step 6. This limited opening degree VOI is, for example, an opening degree of 85% of the determined opening degree VOn, and the restriction on this opening degree is relaxed as hot water supply continues.

The restriction is gradually relaxed based on a detection signal from the outlet hot water temperature thermistor 38 that detects the temperature of hot water flowing out from the heat exchanger 32, and for example, when the outlet hot water temperature due to the restricted opening reaches the set hot water temperature. At this time, the opening degree is increased by 5%, and thereafter, the opening degree is similarly increased by 5%.

By restricting the opening degree in this way, the apparent set temperature is set higher than the actual set temperature, and even in the initial stage of hot water supply when the heat capacity of the heat exchanger 32 is small, You can get hot water that is heated to .

The gas water heater of this embodiment having the above configuration operates as follows.

At time t1, when the user sets the hot water temperature with the hot water temperature setting switch 45b, turns on the operation switch 45a, and opens the faucet (not shown), water flow is detected by the water flow sensor 35 and ignition is started.

When the blower 12 starts rotating and reaches a predetermined rotation speed,
When the sparker 14 is activated and the activation of the sparker 14 is detected, the original solenoid valve 21 and the main solenoid valve 22 are opened, and the burner group 11 is supplied with combustion air and fuel gas.

Further, the opening degree of the bypass valve 33 and the opening degree VOn of the water flow control valve 34 are determined based on the temperature of water flowing into the heat exchanger 32, the set hot water temperature, and the heating capacity of the burner group 11.

When the burner group 11 is ignited at time t2 and the flame is detected by the flame rod 15, the operation of the sparker 14 is stopped.

At this time, the opening degree of the water flow control valve 34 is limited by the opening degree limiting section 47 to the opening degree ■o1 for initial hot water supply (an opening degree of 85% of the opening degree VOn).

At time t3, when the outlet hot water temperature detected by the outlet hot water temperature thermistor 38 reaches the set temperature TO, the opening degree of the water flow control valve 34 is increased by a predetermined opening degree (5%), and the opening degree VO2 (opening degree V
(90% opening of On).

Similarly, the opening degree of the water flow control valve 34 is further increased by a predetermined opening degree (5%) at time t4, and becomes the opening degree VO3 (an opening degree of 95% of the opening degree VOn), and is opened at time t5. Degree VO
n, and the determined opening degree is achieved.

Therefore, the amount of water passing through the heat exchanger 32 and the bypass pipe 32a becomes smaller than the amount of water corresponding to the determined opening degree VOn, and the above set temperature appears to be higher. Therefore, even if the heat exchanger 32 and the like are not sufficiently heated immediately after the start of combustion, a hot water outlet temperature close to the set temperature TO can be obtained, as shown in FIG. 4.

As described above, according to the present invention, when the heat exchanger 32 etc. are not sufficiently heated at the start of hot water supply, the opening degree of the water flow control valve 34 is controlled to be small, and the amount of hot water supplied decreases, so that the water temperature can be reduced. The temperature can be quickly approached to the set temperature.

In addition, in this embodiment, the opening limit is relaxed based on the detection signal of the outlet hot water temperature thermistor, so if there is sufficient heat capacity in restarting the operation, the opening limit is immediately relaxed, so the outlet hot water temperature increases. It never gets too expensive.

In this example, an example of a gas water heater was shown, but
The heating means may be other fuels or electric heaters.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the functional configuration of the control circuit of this embodiment, Fig. 2 is a schematic diagram of the gas water heater of this embodiment, and Fig. 3 shows the opening degree of the water flow control valve of this embodiment. FIG. 4 is a time chart showing changes in hot water temperature in the gas water heater of this embodiment. In the figure, 34... water flow control valve (water flow control means), 38.
... hot water temperature thermistor (temperature detection means), 44... water flow control section (water flow control device of the water heater).

Claims (1)

[Scope of Claims] 1) Detecting the inflow of water into a heat exchanger for heating water and starting heating of a heating means for heating the heat exchanger, and controlling the heating capacity of the heating means and the heat exchanger. A water flow rate control device for a water heater that determines the opening degree of a water flow rate regulating means that adjusts the flow rate of water flowing into the heat exchanger based on the flow rate of water flowing into the exchanger and the temperature of the water flowing out from the heat exchanger. temperature detecting means for detecting the temperature of the temperature detecting means, and at the time of starting water supply, the opening degree of the water amount adjusting means is controlled to be smaller than the determined opening degree, and the opening degree of the water amount adjusting means is controlled to be smaller than the determined opening degree, and the water amount adjusting means is A water flow control device for a water heater, characterized in that the opening degree of a water flow rate adjusting means is gradually changed to a determined opening degree.