JPH04165257A - Detecting method for forced circulation for bath boiler - Google Patents

Abstract

PURPOSE:To dispense with any others but a single detective device by a method wherein changes in the internal pressure in a circulation channel are detected by a water-level detective device and, when a change in the internal pressure is lower than a certain degree, the pump is judged to be malfunctioning. CONSTITUTION:When the forced circulation started by a pump 20 flows in a specified amount, the pressure on the upstream side of the pump 20 becomes lower than the level, detected before the actuation of the pump 20 and the pressure on the downstream side becomes higher than before. Therefore when the output of a water-level detective device 3, which device is provided in the circulation channel, changes by a certain degree between the values before and after the start of the pump 20, it can be judged that the actuation of the pump 20 has effected circulation in a specified amount. If the pump 20 malfunctions or the circulation channel is blocked somewhere, the change between the pressures before and after the start of the pump 20 fails to reach a specified degree; hence the change in the output of the water-level detective device 3 fails to reach a specified degree and the circulation channel can be judged to be malfunctioning.

Description

[Detailed Description of the Invention] [Field of Application and Summary of the Invention] The present invention relates to a method for detecting forced circulation in a bathtub, and in particular, a method for detecting forced circulation in a bathtub. In a bathtub equipped with a type water level detection device, malfunction of the circulation pump can be detected without providing any other detection means.

[Prior art and its n issues] In a bathtub, a heat exchanger for the bath is connected in communication with the bathtub,
The inside of the bathtub is heated in circulation. Recently, this type of bathtub often uses a circulation pump for forced circulation in order to improve circulation heating efficiency and eliminate uneven hot water temperature in the bathtub.

On the other hand, this type of bathtub is used to directly supply (fill) hot water into the bathtub from a separately installed heat exchanger for hot water supply, and to store a certain amount of hot water in the bathtub. A water level switch or the like is provided to detect the water level and prevent dry firing when the water level is below a certain level.

In a bathtub equipped with the above-mentioned hot water filling function, when the bathtub is filled with hot water to a set water level, the filling is stopped by an output from a water level switch or the like. After that, when taking a bath, the inside of the bathtub can be circulated and heated while the pump is running, which improves heating efficiency during reheating. Moreover, the inside of the bathtub is agitated and there is no unevenness in the temperature of the water.

In addition, in the bathtub equipped with the above-mentioned dry heating prevention function, circulating heating is stopped when the water level in the bathtub is below a certain water level, which prevents dry heating by the bath heat exchanger. can.

However, in the bathtub of the above type, there is a problem in that if the pump for forced circulation breaks down, forced circulation heating cannot be performed smoothly. In order to solve this problem, a configuration can be adopted in which a water flow switch is inserted into the forced circulation circuit to detect the water flow generated in response to the operation of the pump.

However, providing a separate detection means just to detect whether or not the pump is operating normally complicates the piping structure and increases the number of parts, making the entire device expensive. Become.

The present invention provides a forced circulation circuit (2) that connects the heat exchanger (1) for an r-bath and the inside of the bathtub (B) so as to enable circulation, and that is equipped with a pump (20) in this circulation circuit. In the bathtub J, in which a pressure-type water level detection element (3) for detecting the water level in the bathtub (B) is arranged in the heat exchanger (1) or in a circulation circuit communicating with the heat exchanger (1), etc. The object is to be able to detect malfunction of the pump (20) without using any detection element.

[Technical Means] The technical means of the present invention taken to solve the above problem is "the heat exchanger (1) before and after the operation of the pump (20)".
Alternatively, the water level detection element (3) detects a change in internal pressure in a circulation circuit equipped with the pump (2o), and when the internal pressure change is below a certain level, it is determined that the pump (20) is malfunctioning. That's J.

[Effect] The above technical means of the present invention operates as follows.

When the pump (20) is in operation, a pressure gradient is generated in the circulation circuit connected to the bath ai (B) at its outlet and inlet sides depending on the capacity of the pump (20). When the forced circulation amount is at a predetermined value due to the operation of the pump (20), the pump (20)
The pressure becomes lower than the detection level before operation of the pump (
20), the pressure is high on the downstream side.

Therefore, if the output value of the water level detection element (3) disposed in the circulation circuit partially changes in level before and after the operation of the pump (20) as described above, the operation of the pump (2o) will cause a certain amount of circulation. It can be determined that this is being done.

If the pump (20) is malfunctioning or part of the circulation circuit is clogged, even if the pump (2o) is working,
The pressure change before and after the operation of the pump (20) does not reach a certain level, and the change in the detection output of the water level detection element (3) also falls below a certain level, so that an abnormality in the circulation circuit can be determined.

[effect] Since the present invention has the above configuration, it has the following unique effects.

The pump (2) depends on the degree of change in the output of the water level detection element (3).
This pump (20
) There is no need to provide a separate detection element to determine whether the pump (20) is operating properly, and the simple configuration
This means that poor operation can be detected.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3.

In the embodiment of the present invention, the bath pot is equipped with a hot water filling device, and a heat exchanger (1) and a heat exchanger (4) for supplying hot water are arranged in parallel in the casing (K). The heat exchanger (1) is a so-called jacket type heat exchanger of a natural circulation type, and has a heat absorption tube provided with a large number of fins (F) between the opposing walls of a cylindrical storage chamber (11). (12) is constructed and communicated with, and a bath burner (13) is disposed below it. One of the constituent walls of the storage chamber (11) includes:
Water pipe (14) for connecting with bath at (B) (1
5) are connected in series, and this is connected to the inside of the bathtub (B) to create a natural circulation circuit (
lO).

For forced circulation, a circuit bypassing the heat exchanger (1) is connected to the wood pipes (14) and (15), and a pump (20) is inserted into this circuit to perform forced circulation. Configure circuit (2). An outlet pipe (22) is provided at the outlet of this forced circulation circuit (2), and an outlet pipe (22) is provided at the outlet of the forced circulation circuit (2).
5), and an artificial pipe (21) is provided in the artificial part and connected to the lower wooden pipe (14).

The artificial pipe (21) and the outlet pipe (22) are made of woodwind (14).
) (15) It is a bent pipe penetrated from the side wall,
The open ends of the inlet pipe (21) and the outlet pipe (22) both face the bathtub (B) side. Further, a sufficient gap is formed between the artificial pipe (21) and the outlet pipe (22) and the inner circumferences of the wood pipes (14) and (15).

In this embodiment, a water pressure gauge (31) is attached to a part of the wall constituting the heat exchanger (1), and this detection output (P) indicates the water level in the bathtub (B) when the pump (20) is stopped. corresponds to the corresponding pressure (Po). And this water pressure gauge (31
) always outputs a detection output while the device is in operation.

In other words, it functions as a water level detection element (3).

The hot water supply circuit of the heat exchanger (4) is branched into a hot water filling circuit (41) for the bathtub (B) and a hot water supply circuit (42) for other places. hopper()I
) is inserted, and an on-off valve (43) for controlling the operation of filling the hot water is inserted upstream thereof.

The on-off valve (43) and the pump (20), as well as the heat exchanger (1) and the burner corresponding to the heat exchanger (4), are controlled by a control device (C). These are controlled by a microcomputer.

This control program executes the operations shown in the flowchart of FIG. 2, and the operations will be explained below.

It should be noted that since the water filling operation is already well known, a detailed explanation of this operation will be omitted, but normally in this type of appliance, when the automatic switch is pressed, the on-off valve (43) opens. At the same time, the heat exchanger (4) goes into operation, and the bathtub (B) is filled with hot water from the hot water filling circuit (41).
When the water level in B) reaches the set water level, the water filling is stopped by the output of the water pressure gauge (31) serving as the water level detection element (3).
In this state, it becomes a standby state.

After this, when the reheating operation is performed, the reheating operation progresses, but in this embodiment, when the reheating switch is turned on, the detected pressure (P) of the water pressure gauge (31) is first read. Remember this. Then pump (2
0) is in the operating state, and the output value from the water pressure gauge (31) at this time and the stored value are compared and calculated. Based on this comparison result, subsequent operations are classified as follows.

■, The difference between the output of the water pressure gauge (31) after the water pump 20) is activated and the output value of the water pressure gauge (31) before the pump (20) is activated is partially at a level (a = 20mmH2o ~ 40mm)
H2o) or higher, the operation of the robot (20) is determined to be normal and the subsequent operation proceeds.

■, If the difference between the output value of the water pressure gauge (31) after the water pump 20) is activated and the output value of the water pressure gauge (31) before the pump (20) is activated is partially below the level (α) ) operation is determined to be defective and subsequent operations are stopped. Or
Issues an alarm to notify that the pump (20) is defective.

When the operation of the pump (20) is normal as shown in (2) above, the burner of the heat exchanger (1) burns and the inside of the bathtub (BJ) is circulated and heated by this heat exchanger (1,). In particular, in this embodiment, a certain period of time (To
), the above-mentioned comparative judgment operation continues, and during this period, the above-mentioned “■
Since the reheating operation will proceed only if the condition ``'' continues, if the detected pressure change shown by ``-'' in Figure 3 is shown, it is judged to be normal, and the condition shown by the broken line in the same figure is determined to be normal. In such cases, it is determined that there is an abnormality. Normally, when the pump (20) is operated, the pressure state quickly changes to that at the time of pump operation, so determining the state indicated by the broken line in FIG. 3 as abnormal is in accordance with the actual situation. In addition, even if there is something wrong with the pump (20), even if an instantaneous pressure change occurs due to some reason and the state shown in "■" above is reached, the output state shown in "■" above will change depending on the subsequent operation. and the pump (20
) can be detected, so there will be no inconvenience in this respect.

Thereafter, when the inside of the bathtub (B) is heated to a desired temperature and the bather turns off the reheating switch, reheating is stopped and the bathtub enters a standby state.

In addition, in this example, the water pressure gauge (31) is connected to the heat exchanger (1).
), and is located between the inlet pipe (21) and outlet pipe (22) of the forced circulation circuit (2) that bypasses the heat exchanger (1), so that the pump (20) When driving,
Since the pressure at the part where the water pressure gauge (31) is installed is lower than the pressure when the pump (20) is stopped, the above cases are classified into "■" and "■" depending on the degree of pressure drop. , if the water level detection element (3) is installed at a location affected by the discharge pressure of the pump (20), the water level detection element (3)
The pressure detected by the water pressure gauge (31) after operation of pump (2)
The operation of the pump (20) is determined to be normal if the level is partially higher than that before the operation of pump (20).

In addition, in this embodiment, the forced circulation circuit (2) is arranged in parallel so as to bypass the heat exchanger (1), but the forced circulation circuit (2) is inserted in series within the heat exchanger (1). It may also be a configuration.

Furthermore, the value of (α) above changes depending on the piping configuration and the installation position of the pressure gauge, and is determined by taking these conditions into consideration.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, and FIG. 2 is a control device (C
) is an explanatory diagram of the main part of the flowchart of the pump (
20) is a graph of pressure changes during operation; (1) Heat exchanger (B) Bathtub (20) Pump (2) Forced circulation circuit (3) Water level detection element

Claims (1)

[Claims] A heat exchanger for a bath (1) and the inside of a bathtub (B) are connected to enable circulation, and a forced circulation circuit (2) equipped with a pump (20) is connected to this circulation circuit so that the inside of the bathtub (B) can be circulated. In a bathtub in which a pressure type water level detection element (3) for detecting the water level inside the bathtub is disposed in the heat exchanger (1) or a circulation circuit communicating with the heat exchanger (1), heat exchange is performed before and after the operation of the pump (20). The water level detection element (3) detects a change in internal pressure in a circulation circuit equipped with a container (1) or a pump (20), and when the change in internal pressure is below a certain level, the pump (20) is activated.
) is determined to be malfunctioning in a bathtub.