JP2908264B2 - One can, two water channel hot water supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-can, two-channel water heater.

[0002]

2. Description of the Related Art In a hot water supply apparatus, in order to supply hot water at a set temperature, a hot water supply temperature Tc, a set temperature Ts and a hot water supply amount Q are calculated. F1 = (Ts-Tc) .times.Q.times.C (1) A given amount of heat F1 (feedforward heat) may be given to the incoming water. Here, C is a constant.

However, since the tapping temperature actually fluctuates depending on the ambient temperature or the like, the actual tapping temperature Th is detected, and the heating amount is corrected based on the difference (Ts-Th) between the set temperature Ts and the actual tapping temperature Th. Perform That is, the heating amount F is calculated as follows: F = F1 × αFB = {(Ts−Tc) × Q × C} × αFB (2) Here, αFB is a feedback correction coefficient. For example, when PID control is performed, a value αFB calculated by αFB = fPID ((Ts−Th) / (Ts−Tc)) (3) is used. When the correction is performed based on the difference between the feedforward calculated value F1 and the actual output, a value αFB calculated by αFB = F value / Q (Th−Tc) (4) is used. There are various other feedback correction methods. For example, the feedback heating amount FB (positive or negative) may be calculated and added to the feedforward heating amount (that is, F = FF + FB).

However, in any of the methods, since the feedback correction controls the next state based on the past state, there is no previous state immediately after the start of tapping, and the feedback correction coefficient αFB ( Or FB)
Cannot be calculated correctly. Therefore, the learning control of sequentially storing the value of the feedback correction coefficient calculated in the steady state, reading out the feedback correction coefficient stored in the immediately preceding steady state immediately after the start of tapping, and using that as an initial value is performed. Is being done.

[0005]

The coefficient C in equation (1), which is a formula for calculating the feedforward calorific value, is set so that hot water at the set temperature Ts is supplied in a steady state. When the state is reached, the feedback correction coefficient αFB should be 1 (or FB = 0). However, the difference in heat efficiency of the heat exchanger for each appliance,
In general, the correction coefficient αFB takes a different value for each appliance even in the steady state due to a difference in the setting of the maximum / minimum gas pressure, a difference in the used gas component, and the like. Conversely, the correction coefficient αFB in the steady state corrects these factors.

On the other hand, in a one-can two-channel water heater, one heat exchanger is provided with a hot water supply channel and a reheating water channel for reheating a bath, and only one of them is heated. In some cases, hot water supply heating and additional heating may be performed simultaneously. Of course, when only hot water heating is performed,
The feedback control based on the above equation (3) or (4) is also performed when both the hot water heating and the supplementary heating are performed simultaneously. However, when only the hot water heating is performed, the correction coefficient αFB Is dependent only on factors such as the difference in heat efficiency of the heat exchanger, whereas when reheating is performed simultaneously with hot water supply heating, the correction coefficient αFB It is also affected by the temperature Tf and the like. Correction coefficient α including such a factor
If the FB is used next time only for hot water supply heating by learning control, erroneous control is performed and overshoot or undershoot of the tapping temperature occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a one-can-two-channel hot water supply apparatus in which learning control of a feedback correction coefficient is correctly performed. To provide a hot water supply device.

[0008]

Means for Solving the Problems, Functions and Effects The present invention has been made to solve the above-mentioned problems. The present invention is directed to a one-can-two-channel type in which a hot water supply side water channel and a reheating side water channel are provided in the same heat exchanger. In the hot water supply apparatus, a) heating amount calculation means for determining a final heating amount by adding a feedback correction based on an actual hot water temperature to a feedforward heating amount calculated from a difference between a set temperature and an incoming water temperature and a hot water amount, b) heating state detecting means for detecting a current heating state; c) a correction value storage area having a plurality of partial storage areas for storing feedback correction values corresponding to each heating state; and d) feedback correction at each time point. Learning means for storing a value in a partial storage area corresponding to the current heating state; ande) when a new heating state starts, reading a feedback correction value corresponding to the heating state from the corresponding partial storage area. Characterized by comprising reading means for providing the heat amount calculating means as an initial value of the feedback correction value.

Here, as one example, in the correction value storage area, a partial storage area for storing a feedback correction value in a hot water supply alone heating state and a partial storage for storing a feedback correction value in a simultaneous hot water supply and additional heating state. And an area.

In the conventional learning control, when heating is once completed in a state where hot water heating and additional heating are simultaneously performed, a feedback correction value at that time is stored, and then heating is started only with hot water. Even in this case, the feedback correction value learned in the simultaneous heating state is read and used as the initial value of the feedback correction value for the hot water supply independent heating. In this case, the following problem occurs. For example, if the temperature of bath water is extremely low during simultaneous heating, the feedback correction value is a value that increases the feedforward heating amount. If such a correction value is used as it is at the start of hot water supply alone heating, the initial heating amount becomes excessive, and the outlet temperature overshoots. On the other hand, the hot water supply device according to the present invention does not use the learning value in the different heating state and reads the feedback correction value stored in the previous same heating state as the initial value,
Such a problem does not occur, and correct control can be started.

As another example, a partial storage area for storing a feedback correction value in a hot water supply only heating state is provided in a correction value storage area (a partial storage area for a feedback correction value in a simultaneous hot water supply and additional heating state is provided). When the simultaneous hot water supply and additional heating state starts, the reading means reads the feedback correction value of the single hot water supply heating state and sets it as an initial value.

In general, in the case of additional heating, precise heating control is often not performed. In this case, even when the hot water supply heating and the supplementary heating are performed simultaneously, it is difficult to say that sufficiently accurate feedback control is performed with respect to the overall heating amount. Therefore, there are various small differences between the previous time and the present time even if the same hot water supply and additional heating simultaneous heating state is used, and there is no guarantee that sufficient control can be started even if the previous learning value is used as it is. This is because correct control can be started by using the feedback correction value obtained in the previous hot water supply single heating state in which sufficiently precise control is performed.

Preferably, the learning means stores the feedback correction value in the corresponding partial storage area after the tapping temperature is stabilized in each heating state.

The feedback correction value before the tapping temperature is stabilized is stored. If the heating state ends at that point, the feedback correction value in the unsteady state is stored in the partial storage area. The unsteady state is not general because it changes from moment to moment. Even if it is used in the same heating state (for example, heating with hot water alone or simultaneous heating with hot water and reheating), the situation in the heating state This is because correct control cannot be performed due to differences in

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A one-can, two-channel hot water supply apparatus according to one embodiment of the present invention will be described with reference to FIG. Since the present hot water supply apparatus 11 is of a one-can, two-water channel type, one heat exchanger 12 is provided with two water channels of a hot water supply channel 13 and a reheating water channel 20. Hot water supply channel 1
3 is connected to the water inlet 15 and the hot water outlet 16,
0 is connected to the suction port and the discharge port of the bathtub 19. The hot water supply water channel 13 is provided with an incoming water temperature sensor 31, a flow rate sensor 32, and a hot water temperature sensor 33, and the additional heating water channel 20 is provided with a circulation pump 21, a bath temperature sensor 34, and a water flow switch 36.

An open / close valve 24 and a proportional valve 25 are provided in a fuel pipe 23 of a burner 22 for heating the heat exchanger 12. The proportional valve 25 is a flow control valve that adjusts the flow rate of the fuel according to an external signal. A fan 26 is provided in the vicinity of the burner 22 and supplies air necessary for combustion of the burner 22.

The temperature and flow rate signals Tc, Q, Th and Tf from these sensors 31, 32, 33 and 34 and the ON / OFF signal of the water flow switch 36 are input to the control unit 50. The control unit 50 is connected with a reheating switch 41, a hot water temperature setting unit 42, and a bath temperature setting unit 43, from which respective signals of the reheating ON / OFF, the set hot water temperature Ts, and the set bath temperature Tfs are input. Is done. Then, the control unit 50
A pump operation signal is sent from the
, A valve opening signal to the proportional valve 25, and a fan operation signal to the fan 26.

The control unit 50 is constituted by a computer having a ROM and a RAM, and performs the following control in accordance with a program stored in the ROM in advance. Less than,
The heating control process performed by the control unit 50 will be described with reference to FIGS. In the following processing, the control unit 50 is functionally configured as shown in FIG.

The control unit 50 performs a heating state detection process as shown in FIG. 3 at fixed short intervals. As shown in FIG. 4, the heating state depends on the presence or absence of hot water supply heating and the presence or absence of additional heating.
It can take a seed state. Regarding hot water supply heating, the water amount Q of the hot water supply channel 13 detected by the flow rate sensor 32 is equal to or more than a predetermined minimum amount Qmin, and the feedforward heating amount F1 calculated by the above equation (1) is a predetermined minimum amount F1min. If it is above, it is determined that there is hot water supply heating. Regarding the additional heating, when the water flow switch 36 provided in the additional heating water channel 20 is ON, it is determined that the additional heating is present. The water flow switch 36 is turned on when the circulating pump 21 is operating and water is present above the suction port in the bathtub 19. Operation control of the circulating pump 21 will be described with reference to FIG. I do.

When the user operates the reheating switch 41,
The signal is input to the control unit 50 by interruption, and the control unit 50 starts the processing in FIG. First, the control unit 50 operates the circulation pump 21 (Step S51). Bathtub 1
When there is water above the suction port in the nozzle 9, the water flow switch 36 is turned on. However, when there is no water to the suction port, the water flow switch 36 is not turned on. 21 is stopped (step S52 → S
55). When the water flow switch 36 is turned on, next, it is determined whether or not the bath temperature Tf detected by the bath temperature sensor 34 is equal to or greater than a value (Tfs-β) obtained by subtracting a predetermined value β from the set bath temperature Tfs. It is determined (step S53), and Tf ≧
When (Tfs-β), additional heating is unnecessary,
The circulation pump 21 is stopped. When Tf <(Tfs-β), the circulation pump 21 is operated until Tf ≧ Tfs (step S54). As described above, the reheating water channel 20
Is circulated only when additional heating is required, so that the additional bath heating is always performed while the bath water is circulated and the water flow switch 36 is ON.

After the current heating state is detected by the above procedure (step S1 and heating state detecting section 56 in FIG. 2), heating control is performed according to each heating state (K10, K01, K11) (steps S2, S3). , S4). First, the procedure of heating control (step S2) in the case of hot water supply alone heating is shown in FIG.
This will be described below. First, it is determined whether or not the current heating state (hot water supply alone heating K10) has changed from the immediately preceding heating state (step S21). For example, reheating is not performed before execution of the present routine, and Q ≧ Qmin and F1 ≧ F1min only after the tapping valve 17 is opened immediately before.
When it becomes, it means that the heating state has changed from K00 to K10. The control unit 50 controls the state variable K (K00, K10, etc.)
Detects that the state has changed this time, the current state K
The feedback correction value αFB corresponding to 10 is read from the memory (step S23 and the FB learning value selecting unit 5 in FIG. 2).
7). As shown in FIG. 2, the memory 60 stores the feedback correction values (FB learning values) for the hot water supply alone heating (K10) and the hot water supply / supplementary heating (K11).
8 and 59 are provided. As will be described later, the feedback correction values αFB are stored in these areas 58 and 59 as FB learning values when the heating state is stabilized. If the immediately preceding state is K00 (non-heated), the on-off valve 24 is opened and the burner 22 is also ignited.

Thus, immediately after the change of the heating state,
After reading the feedback correction value αFB corresponding to the current state from the memory 58 in step S23, the process proceeds to step S26, where the feedback correction value αFB is added to the feedforward heating amount F1 (calculation is performed by the hot water supply heat amount calculation unit 51 in FIG. 2). To calculate the final heating amount F (by the multiplication operator 54 in FIG. 2), and send an opening signal corresponding to the heating amount F to the proportional valve 25 to perform combustion control of the burner 22 (step S27).

Thereafter, if the hot water supply only heating state continues, it is determined in step S21 that there is no state change, so the process proceeds to step S22, where it is determined whether the current heating state is stable (FIG. 2). Stable state determination unit 6
1). The stabilization of the heating state is, for example, that the variation of the tapping temperature Th is within 1 ° C. in the past several seconds (the elapsed time is determined by the timer 62).
) Can be determined. If the heating state is not stable immediately after the start of heating, etc., step S
26 and S27, and as described above, the final heating amount F is calculated using the feedback correction value αFB read out in step S23.
Is calculated, and proportional valve control is performed.

If the heating state is stable, step S2
The process proceeds to step S4, where a feedback correction value αFB is calculated based on the current state (step S24 and the FB calculation unit 55 in FIG. 2). The above formulas (3) and (4) can be used to calculate the feedback correction value αFB. The current feedback correction value αFB thus calculated is stored in the memory 6.
The FB learning value is stored in the storage area 58 corresponding to the current heating state of 0 (step S25), and is used for calculating the final heating amount F (step S26). Therefore,
After entering the stable state, normal feedback control is performed.

In the above example, only one kind of stable heating state is set, the learning value αFB is used until the stable state is reached, and the feedback correction value of the current state is calculated only when the stable state is entered. At the same time, the value is stored in the memory 58 as the learning value. However, the stable state may be divided into two types, and these may be performed separately. That is, when the first (low) stable state is reached, the use of the learning value read from the memory is stopped, the calculation of the feedback correction value in the current state is started, and the calculated value is used to calculate the final heating amount F. Alternatively, when the next (altitude) stable state is reached, the calculated feedback correction value may be stored in the memory as a learning value.

Heating control (Step S2) in the simultaneous heating state (K11) in which both hot water heating and additional heating are performed.
5 will be described with reference to FIG. In this case, the basic procedure is almost the same as the above-described hot water supply independent heating control.
The FB learning value αFB is read from the area 59 corresponding to 0, and is used for calculating the final heating amount F (step S36). The feedforward heating amount in the simultaneous heating state is obtained by adding the additional heating amount F2 (by the additional heating amount calculation unit 52 in FIG. 2) to the hot water supply alone heating amount F1 (the heat amount calculation unit 53).
However, the additional heating amount F2 may be a constant value, or a value according to the number of hot water supplies may be determined as shown in FIG. In the method of FIG. 7, the current bath temperature (Tf = 40 ° C. in FIG. 7) line (dotted line) based on the bath temperature Tf = 45 ° C. line and Tf = 10 ° C. line stored in the ROM. Is interpolated (or extrapolated), and the current number of hot water supply units (the value corresponding to the feedforward heating amount F1 for hot water supply heating) F2 is applied to the line to obtain the additional heating amount (number of bath units) F2.

In the simultaneous heating state, when the heating is stabilized, a feedback correction value αFB reflecting the current state is calculated and multiplied by the feedforward heating amount (F1 + F2) (step S36). It is stored in the storage area 59 (step S35).

In the additional heating alone heating state (K01), as described above, heating is performed by a method such as heating with a fixed number or increasing or decreasing the amount of heating according to the bath temperature Tf. Since no correction is performed and the learning control is not performed, detailed description is omitted.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a one-can two-channel water heater according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a functional configuration of a control unit of the hot water supply apparatus according to the embodiment.

FIG. 3 is a flowchart showing an overall flow of a heating control process.

FIG. 4 is a table showing four types of heating states in Examples.

FIG. 5 is a flowchart (a) of a heating control process in a hot water supply single heating state and a flowchart (b) of a heating control process in a simultaneous hot water supply and additional heating state.

FIG. 6 is a flowchart of a circulation pump operation control.

FIG. 7 is a graph showing one method of determining an additional heating amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Hot-water supply apparatus main body 12 ... Heat exchanger 13 ... Hot-water supply channel 15 ... Water inlet 16 ... Hot-water outlet 17 ... Hot-water valve 19 ... Bathtub 20 ... Reheating water channel 21 ... Circulation pump 24 ... On-off valve 25 ... Proportional valve 31 ... Water-input temperature Sensor 32: Flow rate sensor 33: Hot water temperature sensor 34: Bath temperature sensor 36: Water flow switch

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuro Takada 43-1, Uozakihama-cho, Higashi-Nada-ku, Kobe Japan Inside Yupro Co., Ltd. (56) References JP-A-62-217051 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) F24H 1/00 604

Claims (4)

(57) [Claims] 1. A one-tank two-channel hot water supply system in which a hot water supply side water channel and a reheating side water channel are provided in the same heat exchanger, a) a feed calculated from a difference between a set temperature and an input water temperature and a hot water supply amount. Heating amount calculating means for determining the final heating amount by adding a feedback correction based on the actual tapping temperature to the forward heating amount; b) heating state detecting means for detecting the current heating state; c) corresponding to various heating states A) a correction value storage area having a partial storage area for storing a feedback correction value to be performed; d) learning means for storing the feedback correction value at each time in a partial storage area corresponding to the current heating state; When the state starts, a feedback correction value corresponding to the heating state is read out from the corresponding partial storage area, and readout means is provided to the heating amount calculation means as an initial value of the feedback correction value. A can two conduit-type hot water supply apparatus characterized by obtaining. 2. The correction value storage area includes a partial storage area for storing a feedback correction value in a hot water supply only heating state and a partial storage area for storing a feedback correction value in a simultaneous hot water supply and additional heating state. Item 1. A one-can, two-channel water heater. 3. The correction value storage area includes a partial storage area for storing a feedback correction value of the hot water supply only heating state, and when the simultaneous hot water supply and additional heating state is started, the reading means performs feedback correction of the hot water supply single heating state. 2. The one-can, two-channel hot water supply apparatus according to claim 1, wherein the value is read and set as an initial value. 4. The one-can, two-channel hot water supply apparatus according to claim 1, wherein the learning means stores the feedback correction value in the corresponding partial storage area after the tapping temperature is stabilized in each heating state.