KR910005445B1 - Temperature control apparatus for water providing system - Google Patents

Abstract

The device is used for controlling the temperature of water discharged from the heat exchanger in a gas-fired burner or bunsen type burner or electric heater etc.. The amount of heating on the heat exchanger is controlled by temperature of water flowing into heat exchanger and the flow rate of water flowing through heat exchanger. The temperature of water discharged from heat exchanger is determined by the heating amount. The device comprises calculating menas for calculating the temperature of the heat exchanger according to thermal capacity of the heat exchanger and the temperature of the discharged water; calibrating means for calibrating the heating amount on the heat exchanger according to the calculating temperature of the heat exchanger.

Description

Temperature controller of hot water heater

1 is a block diagram showing the functional configuration of a control device for a gas water heater showing an embodiment of the present invention.

2 is a schematic configuration diagram showing a gas water heater of this embodiment.

3 to 5 are views for explaining the operation of the present embodiment, respectively,

3 is a timing chart showing a change in the hot water supply flow rate and a change in the reference heating amount in the feedforward control.

4 is a timing chart showing changes in the amount of combustion in the combustor of this embodiment.

5 is a timing chart showing a change in hot water temperature.

6 is a characteristic diagram showing the change in the heat exchanger virtual temperature (B _n ).

7 is a characteristic diagram showing the change of the transient heat transfer component (K _n ).

* Explanation of symbols for main parts of the drawings

40: control device 43: calorie calculation means

44: correction means

The present invention relates to a temperature controller of a hot water heater, which controls the hot water flowing out of the heat exchanger to a predetermined temperature by controlling heating means for heating the heat exchanger.

In a conventional hot water heater, heating means such as a burner or an electric heater is controlled by feedforward in accordance with the water supply temperature and the water supply amount set temperature so as to obtain a required water supply temperature according to the needs of the user.

However, even if the amount of combustion changes or the set temperature is changed immediately accordingly, even if the amount of combustion changes immediately, the heat exchanger through which the heated water passes has a residual heat amount due to heat capacity due to its material, shape and size. The heating amount of does not become the set temperature unless the time until the heat exchanger reaches the thermal equilibrium does not reach the set temperature, and is heated excessively or the heating amount is insufficient. Therefore, there is a problem that it takes time until the hot water supply of the set temperature is performed after such a change.

An object of the present invention is to provide a temperature control device for a hot water heater in which hot water supply is performed quickly even when the quantity of water or the set temperature is changed.

The present invention provides a control means for controlling the temperature of the water flowing into the heat exchanger and the flow rate of the heat exchanger from the flow rate of the water passing through the heat exchanger to control the hot water flowing out of the heat exchanger to a set temperature in order to achieve the object. In the temperature control device of the hot water heater, the control means is a calculation means for calculating the temperature of the heat exchanger based on the heat capacity of the heat exchanger and the temperature of the hot water flowing out of the heat exchanger and the heat exchanger calculated by the calculation means It is a technical means to provide heating amount correction means which corrects the heating amount of the said heat exchanger based on the temperature of the machine.

In the present invention, the amount of heating to the heat exchanger is controlled based on the amount of inflow water at the inflow temperature to the heat exchanger, and the hot water supply at the set temperature is performed. In the control of the heating amount, the calculation means calculates the temperature of the heat exchanger based on the heat capacity of the heat exchanger and the temperature of the hot water flowing out of the heat exchanger, and corrects the heating amount based on the calculated temperature of the heat exchanger. Therefore, when the inflow temperature, the inflow water amount changes, or the set temperature is changed, the heating amount is corrected based on the temperature of the heat exchanger at the time of change, so that the influence of the heat accumulated in the heat exchanger may appear at the tapping temperature. There is no excessive heating and lack of heating due to the heat amount of the heat exchanger, and the tapping of the set temperature is performed quickly.

Next, the present invention will be described based on the embodiments shown in the drawings.

The gas water heater of this embodiment shown schematically in FIG. 2 is composed of a combustor 10, a fuel pipe 20, a water pipe 30, and a control device 40.

The combustor 10 is a heating means of the present invention, and is composed of a burner plate 11 installed in the hot water heater case 1 and a blower 12 for supplying combustion air, and the burner is a fuel gas supplied from the nozzle 13. The primary air combustion is performed by burning only by the combustion air supplied by the blower 12, and the combustion gas is discharged from an outlet not shown. Above the burner plate 11, a flame rod 15 and a derma coupler 16 for detecting the sparker 14 flame of the ignition device are respectively provided.

The fuel pipe 20 supplies the fuel gas to the nozzle 13, and sequentially adjusts the fuel supply amount to the burner plate 11 and the original solenoid valve 21, the kettle valve 22, and the upstream side thereof. Proportional valves 23 are respectively provided, branched downstream of the proportional valve 23, the branched fuel pipe 20 is provided with a switching solenoid valve 24 for controlling the amount of combustion by cutting off fuel. On the other side, an orifice 25 for limiting the fuel supply amount to the burner plate 11 is provided.

The water pipe 30 is composed of a supply pipe 31 and a hot water supply pipe 31a connected to a water supply source and a hot water supply port, which are not shown, and a heat exchanger 32 and a bypass pipe 32a communicating therewith. A part of the water to be supplied passes through the heat exchanger 32, and the remaining part passes through the bypass pipe 32a to be led to the hot water supply pipe 31a, and merges with the heat exchanger 32 and the bypass pipe 32a. The bypass valve 33 is provided in the part, and the ratio between the water heated by the heat exchanger 32 and the water induced without being heated by the bypass pipe 32a is appropriately adjusted and mixed.

On the other hand, the water supply control valve 34, the water flow sensor 35 and the water inlet dummyster 36 from the upstream of the supply pipe 31 and the heat exchange dummyster 37 downstream of the heat exchanger 32 and the hot water heater 31a. ), The tapping is provided with a dummyster 38, respectively.

In addition, the bypass valve 33 and the water quantity control valve 34 are driven by a gear motor provided respectively, and a potentiometer is provided for detecting the opening degree, and the water flow sensor 35 has a supply pipe 31. It outputs a pulse signal of the number corresponding to the rotational speed of an unshown vane rotated by the water flow passing through the inside.

The control device 40 is constituted by a microcomputer and a driving circuit, and the microcomputer is a function unit, as shown in FIG. 1, a sequence control unit 41, a reference heating amount determining unit 42, and a calorie calculating unit that manage an operating sequence as shown in FIG. 43), the correction part 44, the combustion control part 45, and the quantity control part 46, The control apparatus 40 is equipped with the controller 47 operated by a user. The sequence control unit 41 starts ignition operation by a predetermined sequence based on the communication signal from the water flow sensor 35 and the operation signal from the controller 47, and starts combustion at the same time when abnormal combustion, lack of capacity, etc. Stops the operation of the combustor 10 as a whole or the fuel supply when combustion is performed under preset conditions.

The reference heating amount determining unit 42 determines the reference value at time n as feedforward control based on the set temperature set by the controller 47 and the signals from the inlet temperature dummyster 36 and the water flow sensor 35. Determine the amount of heat FF _n .

Here standard moving heat (FF _n) is a set temperature (T _set), to obtain temperature (T _in), is determined from the input quantities (W), the thermal efficiency (eff) to the _{FF n = (T set- T in} ) × W / eff .

The calorific value calculating section 43 calculates the calorific value of the heat exchanger 32 on the basis of the detected temperature by the heat exchanger dummyster 37 when the capacity control of the combustion amount is started after a predetermined time has elapsed after commencement of combustion. Let it be the initial value of the temperature of group 32.

Here, at time _n , the initial value B _o of the virtual temperature B _n of the heat exchanger 32 is based on the tapping temperature T _e from the heat exchanger 32 B _o = e × T _e +. Obtained by f (e, f are integers based on the heat capacity of the heat exchanger), and improves the rapid rise characteristic of the tapping temperature during ignition and re-ignition.

The correction unit 44 is a functional unit for correcting the combustion amount of the combustor 10 based on the calculation result of the calorific value calculating unit 43.

Here, the change amount of the reference heating amount FF _n by the reference heating amount determining unit 42 is monitored, and the heat exchanger is changed from the gradient of the calculated initial value B _o of the heat exchanger 32 and the reference heating amount FF _n . The imaginary temperature B _n [C] of the heat exchanger 32 at time n is sequentially obtained by the period of 32 at a predetermined unit time Δt (for example, 0.5 second).

B _n = A _n + (B _n -1-A _n ) × b

Where b is the time constant and the virtual temperature (A _n ) [C] in the steady state of the heat exchanger (32) is determined by the reference heating amount (FF _n ).

A _n = c × FF _n + d

Obtain by Where c and d are both integers.

Then, based on the virtual temperature A _n in the steady state of the heat exchanger 32 and the virtual temperature B _n of the heat exchanger 32 at the time n, the time n in the abnormal state is Transient heat transfer component (K _n )

K _n = d × (A _n -B _n -1)

The amount of correction combustion of the combustor 10 is determined using this transient heat transfer component K _n as a correction value, and the correction time is taken while the transient heat transfer component K _n is calculated.

Therefore, when the heat exchanger 32 is in the steady state of the virtual temperature A _n1 , for example, when the water supply amount decreases, the virtual temperature B _n of the heat exchanger 32 at time _{n is} shown in FIG. 6. As shown in the figure, the secondary temperature is sequentially changed to sequentially approach the virtual temperature B _n of the steady state, and accordingly, the transient heat transfer component K _n gradually decreases as shown in FIG.

The combustion control unit 45 is determined by the reference heating amount determination unit 42 and according to the combustion amount corrected by the correction unit 44, the blower 12 of the combustor 10, the proportional valve 23, the solenoid valve for conversion. To control (24). In this case, since the correction of the combustion amount is performed by the correction unit 44 as described above, when the hot water supply amount is changed or the set temperature is changed by the user, and thus the combustion amount is required to be changed, the heat exchanger 32 before the change is made. Since the new combustion amount and its output time are determined based on the excess heat amount or the insufficient heat amount accumulated in the c), the combustion amount is not excessive or insufficient, and the temperature of the hot water flowing out of the heat exchanger 32 can be changed quickly.

Then, the control of the air-fuel ratio is performed by the output of the dermacouple 16.

The water quantity control unit 46 controls the water quantity control valve 34 in accordance with the determined combustion amount of the reference heating amount determining unit 42, and at the same time, the hot water controls the bypass valve 33 based on the detection signal of the dummyster 38. do.

The controller 47 starts the hot water heater operation and sets the tapping temperature according to the user's purpose. And a liquid crystal display for displaying the set temperature or a combustion lamp to indicate that the combustion of the combustor 10 is provided to inform the user of the operating state.

In addition, the control device 40 also performs feedback control by the detection signal of the heat exchange dummyster 37 and corrects the combustion amount of the combustor 10 when the hot water flowing out of the heat exchanger 32 becomes a predetermined condition. .

The gas water heater with the above structure operates as follows.

When the user sets the tapping temperature by the controller 47, the operation switch is turned on, and the tap water is operated without a city, ignition is performed by a predetermined sequence, and the combustion of the combustor 10 starts, and at the same time, it flows out of the tap without water. do.

When a predetermined time has elapsed, the combustion amount control according to the set temperature of the controller 47 is started from the combustion amount of the ignition initial stage, and the reference heating amount is determined based on the obtained water temperature, the obtained water quantity and the set temperature.

Then, the blower 12 is controlled according to the heating amount, the combustion air is supplied according to the heating amount, and the rotation speed of the blower 12 is detected, and the current flows through the proportional valve 23 according to the detected rotation speed. . Water supplied from the supply pipe 31 is divided into the heat exchanger 32 and the bypass pipe 32a, respectively, and flows through the bypass pipe 32a without being heated with the water heated in the heat exchanger 32. One of the water is mixed in the ratio of the bypass valve 33 to be mixed and hot water.

When hot water supply is continued and thermal equilibrium of the heat exchanger 32 is obtained, the outflow temperature from the heat exchanger 32 is detected by the heat exchange dummyster 37, and the temperature and the heat capacity of the heat exchanger 32 previously calculated. Based on this, the temperature of the heat exchanger 32 is calculated and taken as an initial value.

Thereafter, when the flow rate is changed from V ₁ to V ₂ by the user at time t _{1 as} shown in FIG. 3, the reference heating amount is also changed from q ₁ to q ₂ as shown in FIG. 3. In the corrector 44, the corrected combustion amount and the corrected time of the combustor 10 are calculated based on the initial value of the temperature of the heat exchanger 32 and the changed reference heating amount, and the combustor according to the amount of heat corrected by the combustion control unit 45. To control (10).

As a result, the combustion amount of the combustor 10 is changed in a short time from Q ₁ to Q ₂ as shown in FIG. 4, after which the combustion amount is changed again from Q ₂ to Q ₃ in accordance with the correction time after the correction 44. Therefore, the hot water supply temperature flowing out from the heat exchanger 32 shows a temperature T _{1 which} is almost constant in accordance with the set temperature without being greatly changed as shown in FIG.

Then, the hot water supply amount is changed again at time t ₂ , and when the flow rate is V ₃ , the reference heating amount is changed to q ₃ , but the combustion amount of the combustor 10 is changed in a short time from Q ₃ to Q ₄ . Then, it is changed to Q ₅ in turn. Outlet temperature from the results, the heat exchanger 32 can be to a temperature (T ₁₎ according to the set temperature.

As described above, according to the present invention, when the amount of hot water is changed by the user, and the amount of combustion is changed, the amount of combustion of the combustor is corrected based on the temperature of the heat exchanger, so that it is heated to the set temperature without excessive heating or lack of heating amount. Hot water supply can be performed.

In the present embodiment, the case where the set temperature is constant and the amount of hot water supply is explained, but even when the flow rate is constant and the set temperature is changed, when the combustion amount is changed accordingly, the combustion amount is similarly corrected. The hot water supply temperature can be quickly corrected to the newly set temperature.

In the above embodiment, the gas water heater using the burner of the primary air combustion type has been described, but may be a heating means such as a Bunsen burner, an oil burner, or an electric heater.

Claims (1)

In the temperature control apparatus of the hot water heater provided with the control means which controls the heating amount with respect to the heat exchanger from the temperature of the water which flows into a heat exchanger, and the flow volume of the water which passes through the heat exchanger, and makes hot water flowing out from the heat exchanger into a set temperature, The control means may be configured to calculate the temperature of the heat exchanger based on the heat capacity of the heat exchanger and the temperature of the hot water flowing out of the heat exchanger, and based on the temperature of the heat exchanger calculated by the calculation means. And a heating amount correcting means for correcting the heating amount.

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