JP2577477B2 - Fluid heating controller - Google Patents

Description

The present invention relates to a fluid heater, target temperature setting means for setting a target temperature of a fluid to be heated at an outlet side of the fluid heater, and the fluid heater. Inlet temperature detecting means for measuring the temperature of the fluid to be heated at the inlet side of the fluid heater, and outlet temperature detecting means for measuring the temperature of the fluid to be heated at the outlet side of the fluid heater, and the detection of the two temperature detecting means is provided. The present invention relates to a fluid heating control device provided with control means for adjusting a heating state of the fluid heater so that the fluid to be heated reaches the target temperature based on information.

[Conventional technology]

As the fluid heater, for example, a water heater can be mentioned. In other words, the water temperature before heating and the water temperature after heating are detected, and the hot water supply temperature is made to coincide with the target temperature by automatically controlling the amount of heating and the amount of flowing water.

Conventionally, in the fluid heating control device as described above, the heating state of the fluid heater is always controlled based on detection information of both the inlet temperature detecting means and the outlet temperature detecting means, and the inlet temperature detecting means or the outlet temperature detecting means When any one of the above fails, the fluid heating control is stopped.

However, in such a conventional configuration, there is an inconvenience that the inlet temperature detecting means cannot be used if any of the outlet temperature detecting means fails, and Japanese Utility Model Application Laid-Open No. 61-181942 discloses such an inconvenience. The hot water supply device disclosed in the official gazette has been proposed.

In the hot water supply apparatus, when the inlet temperature detecting means fails, feedback control is performed based on the set target temperature and the temperature detected by the outlet temperature detecting means, and when the outlet temperature detecting means fails, the target temperature and the inlet temperature detecting means And the feed-forward control is performed based on the detected temperature of the hot water supply device, so that the hot water supply device can be used even if either the inlet temperature detecting means or the outlet temperature detecting means fails.

[Problems to be solved by the invention]

However, in the hot water supply device disclosed in the above publication, the feedforward control is performed using the set target temperature as it is in a situation where the outlet temperature detecting means fails and the actual hot water temperature after heating cannot be detected. Therefore, a deviation may occur between the actual hot water temperature after heating and the target temperature, and hot water higher than the target temperature may be supplied.

In other words, in order to supply hot water at the target temperature, it is necessary to reliably control the amount of water flowing through the heater and the heating state of the heat source as desired, but this is practically almost impossible and therefore, Usually, the feedback control is executed in parallel with the feedforward control.
In such a situation, if only the feedforward control is executed using the set target temperature as it is, it is inevitable that a deviation occurs between the actual hot water temperature and the target temperature,
As a matter of course, there is a risk that hot water having a temperature higher than the target temperature is supplied.

An object of the present invention is not only to be able to use even when one of the inlet temperature detecting means and the outlet temperature detecting means fails, but also to use at the time of the failure, a high temperature fluid to be heated at a target temperature or higher. An object of the present invention is to provide a fluid heating control device which can be used safely by avoiding supply as much as possible.

[Means for solving the problem]

In order to achieve this object, a first characteristic configuration of the fluid heating control device according to the present invention is provided with a failure detection means for detecting a failure of the temperature detection means, and the control means detects the failure of the failure detection means. Based on the information, when the inlet temperature detecting means fails, the heating state of the fluid heater is adjusted based on the target temperature and the temperature detected by the outlet temperature detecting means, and the outlet temperature detecting means fails. Then, the heating state of the fluid heater is adjusted with a target temperature lower than the target temperature based on the target temperature and the temperature detected by the inlet temperature detecting means.

A second characteristic configuration is that when the inlet temperature detecting means fails, the temperature of the fluid to be heated at the inlet side of the fluid heater is set to a preset assumed temperature, and the assumed temperature and the detection of the outlet temperature detecting means are detected. The heating state of the heater is adjusted based on the temperature so that the fluid to be heated reaches the target temperature.

Incidentally, the adjustment of the heating state of the fluid heater is specifically performed by adjusting the flow rate of the fluid to be heated in a state where the heat source is in the maximum heating state or by adjusting the heating state of the heat source. There is.

A third characteristic configuration is that, when either the inlet temperature detecting means or the outlet temperature detecting means has failed based on the detection information of the failure detecting means, a display means for displaying the failure information is provided. is there.

(Operation)

In the first characteristic configuration, even if one of the inlet temperature detecting means and the outlet temperature detecting means fails, the heating state of the fluid heater is adjusted by using the detection information of the other temperature detecting means. The use of the device becomes possible.

In this case, when the inlet temperature detecting means fails, in addition to the set target temperature, the outlet temperature detecting means detects the actual temperature after heating, and adjusts the heating state of the fluid heater based on the detected temperature. Therefore, supply of the fluid to be heated having a temperature higher than the target temperature is avoided. Further, when the outlet temperature detecting means fails, the target temperature is not used as it is, but a temperature lower than the target temperature is set as a target, and the heating state is adjusted based on the lower target temperature and the detected temperature of the inlet temperature detecting means. Therefore, even when the outlet temperature detecting means fails, the supply of the heated fluid higher than the set target temperature is avoided.

In the second characteristic configuration, when the inlet temperature detecting means fails,
Since the temperature at the inlet side of the fluid heater is assumed to be a certain value and the heating state is adjusted using the assumed temperature at the inlet side, the time required to reach the set target temperature can be reduced. Nevertheless, by setting the assumed temperature on the inlet side higher than usual, the supply of the fluid to be heated to a high temperature is also avoided in this case.

In the third characteristic configuration, it is possible to know that one of the temperature detecting means is out of order, so that it is possible to prepare for repair while using the fluid heating control device.

〔The invention's effect〕

In the first characteristic configuration, even if one of the inlet temperature detecting means and the outlet temperature detecting means fails, it can be used, and at the time of use at the time of the failure, the heated fluid having a temperature higher than the set target temperature can be used. It can be used safely by avoiding supply.

In the second characteristic configuration, in addition to the effect of the first characteristic configuration, even when the inlet temperature detecting means fails, the time required to reach a temperature close to the set target temperature is shortened, and so-called rise is accelerated. be able to.

In the third characteristic configuration, the temperature detecting means can be used even when the temperature detecting means has a failure, but the failure can be known, and the subsequent measures such as repair can be promptly performed.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a hot water supply control device as an example of a fluid heating control device will be described with reference to the drawings.

As shown in FIG. 1, a casburner (1) as a heat source
A water heating heat exchanger (2) as a fluid heater heated by the water heater is connected to a hot water tap (4) via a hot water supply path (3). (6) in the figure is a water supply device for the heat exchanger (2).

Fuel gas supply path (8) for the gas burner (1)
Is provided with a gas valve (9) for intermittently supplying fuel gas and an electromagnetic gas amount adjusting valve (10) for adjusting fuel gas supply amount.

The hot water supply path (3) is provided with an electromagnetic flow control valve (11) for adjusting the amount of hot water.

A control device (15) is provided as control means configured using a microcomputer.
5) The hot water supply control is executed,
Hereinafter, the hot water supply control will be described.

A water flow sensor (1) that detects the water flow through the heat exchanger (2)
6), an inlet water temperature sensor (17) as an inlet temperature detecting means for detecting a temperature of water supplied to the heat exchanger (2), and a hot water as an outlet temperature detecting means for detecting an outlet hot temperature of the heat exchanger (2). A temperature sensor (18) is provided, and detection information of these sensors is input to the control device (15).

Further, a remote controller (20) for instructing the control device (15) with operation information is provided. The remote controller (20) includes an operation switch (21) for instructing start / stop of the hot water supply operation, A hot water supply temperature setter (22) as target temperature setting means for setting hot water supply temperature and a display lamp (23) as display means for displaying failure information of both temperature detection means (17) and (18) are provided. ing.

The hot water supply operation is started when the control device (15) is turned on and the operation switch (21) is turned on and operated. Then, when the water flow sensor (16) detects the start of water supply with the opening of the hot water tap (4), the gas valve (9) is opened based on the detection of the start of water supply, the gas burner (1) is ignited, and hot water supply is started. I do.

Then, while adjusting the gas amount adjusting valve (10) to the combustion amount set upper limit value (G) (G _M) of the gas burner (1), set the hot water temperature which is commanded from a remote controller (20) Based on (T ₁ ) and the detected feed water temperature (Ti) of the incoming water temperature sensor (17), the flow control valve is adjusted so that the detected flow rate (W) of the water flow sensor (16) substantially satisfies the following expression. Adjust (11).

W = G _M / (T ₁ −Ti) where the detected hot water temperature of the hot water sensor (18) is based on the deviation between the detected hot water temperature (Tj) of the hot water temperature sensor (18) and the set hot water supply temperature (T ₁ ). as to match the (Tj) of the set temperature (T _1), adding the correction to the adjustment control of the aforementioned flow control valve (11).

That is, based on the following equation (a), the flow control valve (11)
Is performed.

W = G _M / (T ₁ −Ti) + K ₁ (Tj−T ₁ ) ( ₁ ) where K ₁ is a preset correction coefficient.

The hot water supply control is basically performed as described above, but the hot water supply control when either the incoming water temperature sensor (17) or the hot water temperature sensor (18) fails will be described below.

Using the control device (15), both sensors (17), (18)
A failure detecting means (F) for detecting the failure of the above is provided.

In addition, both the sensors (17) and (18) are each constituted by a thermistor, and a bridge circuit is constituted by using the thermistors. That is, the resistance value of the thermistor changes with the temperature change. As a result, the output voltage of the bridge circuit changes, so that the temperature is detected. The output voltage of the bridge circuit increases as the detected temperatures (Ti) and (Tj) increase. Incidentally, the detected temperatures (Ti) and (Tj) are within a predetermined range (for example, -20 ° C).
~ 120 ° C) is usually not conceivable. Therefore, if the output voltage is equal to or lower than the voltage corresponding to the lower limit of the predetermined temperature range or equal to or higher than the voltage corresponding to the upper limit of the predetermined temperature range, it is determined that the sensors (17) and (18) have failed. It is.

When incoming water temperature sensor (17) has failed to adjust the heating condition of the heat exchanger (2) on the basis of the set target temperature (T ₁₎ and the detected temperature of the hot water temperature sensor (18) (Tj). That is,
Assuming that the incoming water temperature is 25 ° C., the adjustment control of the flow control valve (11) is performed based on the following equation (b).

W = G _M / (T ₁ −25) + K ₁ (Tj−T ₁ ) (b) When the hot water temperature sensor (18) fails, the set target temperature (T ₁ ) and the incoming water temperature sensor (17) The heating state of the heat exchanger (2) is adjusted based on the detected temperature (Ti). However, the target temperature is a predetermined temperature (T _K ) lower than the set target temperature (T ₁ ). That is, the adjustment control of the flow control valve (11) is performed based on the following equation (c).

W = G _M / (T ₁ −T _K −Ti) (C) Next, the operation of the control device (15) will be described based on the flowchart shown in FIG.

An initialization process for clearing various stored values is performed as the power is turned on.

Next, the necessity of hot water supply is determined based on the information of the operation switch (21). If the hot water supply is unnecessary, it is determined whether or not hot water is being supplied up to the present. If hot water is not being supplied until now, the process will shift to the initial setting process,
If hot water is being supplied to the present, the process proceeds to the initial setting process after performing the fire extinguishing process.

When it is determined that the hot water supply is required, it is determined whether or not the water amount is equal to or less than the set value based on the detection value of the water amount sensor (16). If the amount of water is less than the set value, it is determined whether or not hot water is being supplied until now. If hot water is not being supplied to the present, the process proceeds to the initial setting process. If hot water is being supplied to the present, the process proceeds to the initial setting process after performing the fire extinguishing process.

If it is determined in the above determination that the water amount is equal to or greater than the set value, it is determined whether or not ignition is being performed. Only when the ignition is not being performed, the ignition process for igniting the gas burner (1) is performed. Is executed.

Then, a water proportional process for adjusting the combustion state of the gas burner (1) and the flow state of the heat exchanger (2) is executed so as to maintain the set hot water supply temperature (T ₁ ). Here, based on the detection information of the incoming water temperature sensor (17) and the hot water temperature sensor (18),
The fault state of both sensors (17) and (18) is determined. If both are normal, the formula (A) is used. If the incoming water temperature sensor (17) is faulty, the formula (B) is used. The hot water temperature sensor (18) is faulty. In this case, the adjustment control of the flow control valve (11) is performed based on the expression (c). When either of the sensors (17) and (18) fails, a failure is displayed. After the water proportional process is performed, the process proceeds to a process of determining whether hot water supply is necessary.

(Another embodiment)

In the above embodiment, when the incoming water temperature sensor (17) fails, the heating state of the heat exchanger (2) is adjusted by assuming the incoming water temperature (Ti) to be 25 ° C., but the burner (1) The outlet water temperature detected before combustion can be used as the inlet water temperature. or,
It can also be controlled without using the incoming water temperature (Ti). In this case, the amount of increase or decrease in the flow rate (W) is adjusted based on the deviation between the set target temperature (T ₁ ) and the temperature (Tj) detected by the hot water temperature sensor (18).

In the above embodiment, the hot water supply temperature is controlled by adjusting the water flow rate (W).
May be adjusted. In this case, a constant flow rate may be maintained by using a water governor instead of the flow control valve (11).

Further, the adjustment of the flow rate (W) and the adjustment of the combustion quantity (G) may be used in combination.

In the above embodiment, the case where the present invention is applied to the hot water supply control device is described, but the present invention can also be applied to a heating heater or the like.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[Brief description of the drawings]

The drawings show an embodiment of the fluid heating control device according to the present invention,
FIG. 1 is an overall configuration diagram of a hot water supply control device, and FIG. 2 is a flowchart of a control operation. (1) Heat source (2) Fluid heater (15) Control means (17), (18) Temperature detection means (22)
Target temperature determination means, (23) display means, (F) failure detection means, (T ₁ ) target temperature, (Ti), (Tj)
Detection temperature.

Claims (5)

(57) [Claims] 1. A liquid heater (2); target temperature setting means (22) for setting a target temperature (T ₁ ) of a fluid to be heated at an outlet side of the liquid heater (2); Inlet temperature detecting means (17) for measuring the temperature of the fluid to be heated at the inlet side of (2), and outlet temperature detecting means (18) for measuring the temperature of the fluid to be heated at the outlet side of the fluid heater (2) And both temperature detecting means (17),
Fluid heating provided with control means (15) for adjusting the heating state of the fluid heater (2) based on the detection information of (18) so that the fluid to be heated reaches the target temperature (T ₁ ). A control device, comprising: a failure detecting means (F) for detecting a failure of the two temperature detecting means (17) and (18);
When the inlet temperature detecting means (17) fails based on the detection information of the failure detecting means (F), the target temperature (T ₁ ) and the detected temperature (Tj) of the outlet temperature detecting means (18)
And the heating state of the fluid heater (2) is adjusted based on the above, and when the outlet temperature detecting means (18) fails, the target temperature (T ₁ ) and the inlet temperature detecting means (17)
A fluid heating controller configured to adjust a heating state of the fluid heater (2) with a target temperature lower than the target temperature (T ₁ ) based on the detected temperature (Ti). 2. The fluid heater (2), wherein the control means (15) operates when the inlet temperature detection means (17) fails.
The temperature of the fluid to be heated on the inlet side of the nozzle is defined as a predetermined assumed temperature, and the assumed temperature and the outlet temperature detecting means (1
8) The fluid heater (2) such that the fluid to be heated reaches the target temperature (T ₁ ) based on the detected temperature (Tj) of (8).
The fluid heating control device according to claim 1, wherein the fluid heating control device is configured to adjust a heating state of the fluid heating device. 3. The method according to claim 1, wherein the heating state of the fluid heater is adjusted by adjusting the flow rate of the fluid to be heated while the heat source is in a maximum heating state. 3. The fluid heating control device according to 2. 4. The fluid heating control device according to claim 1, wherein the heating state of the fluid heater (2) is adjusted by adjusting the heating state of the heat source (1). 5. A display means for displaying, when either the inlet temperature detecting means (17) or the outlet temperature detecting means (18) has failed based on the detection information of the failure detecting means (F), the failure information is displayed. 5. The method according to claim 1, wherein (23) is provided.
The fluid heating control device according to any one of the above.