JPH06288624A - Control method for a plurality of parallel type water heaters - Google Patents

Abstract

PURPOSE:To prevent the spillage of chilled water from a hot water supply cock by closing a hot water delivery solenoid valve of a water heater with which communicate is determined impossible control the number of units with the remaining water heaters. CONSTITUTION:When a water heater 1 is placed in a communication failure by a disconnection or the like, the water heater 1 fails to start the operation of delivering hot water a hot water delivery solenoid valve 19 closed and while a hot water delivery solenoid valve 92 of the a water heater 2 is opened and the water heater 2 starts the operation of delivering hot water. Thus, it is ascertained that the communication state of the water heaters 1, 2 and 3 is normal and then, the individual hot water delivery solenoid valves 91, 92 and 93 are opened thereby eliminating possibility of supplying chilled water from the water heater disabled to communicate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method for a parallel type multiple water heater in which a plurality of water heaters are connected in parallel to increase the range of hot water supply capacity.

[0002]

2. Description of the Related Art Conventionally, by connecting a plurality of water heaters in parallel, it is possible to increase the range of hot water supply capacity of each water heater (for example, the range from the minimum hot water discharge amount to the maximum hot water discharge amount). In such a parallel type multiple water heater, the number of hot water heaters to be operated is controlled when increasing or decreasing the amount of hot water discharged according to the increase or decrease in the amount of hot water consumed.

For example, the one disclosed in Japanese Patent Laid-Open No. 64-63749 is a parallel type water heater having two or more water heaters each having a water amount adjusting valve and a hot water discharge solenoid valve connected to each other. When one hot water heater is in operation and the amount of hot water discharged, that is, the amount of hot water consumed, reaches the maximum hot water discharge capacity of one hot water heater in operation, the hot water solenoid valve of the second and subsequent hot water heaters is opened. To start the operation, and to stop the water heaters sequentially in the reverse order of when combustion was started when the amount of hot water discharged decreased below a predetermined value when two or more were operating. The hot water supply solenoid valve provided in the hot water supply device is fully closed when the hot water supply device to which the hot water supply solenoid valve is attached stops burning, and is fully opened when the operation switch of the parallel-type multiple hot water supply device is turned off. This ensures the amount of water used when using cold water from the hot water tap. It had to be able to carry out the drainage.

[0004]

However, in the control of the above-described conventional parallel type multiple water heaters, when the operation switch is turned on and one of the second and subsequent water heaters is in the hot water discharge operation, a disconnection or the like occurs. If communication with the water heater becomes impossible due to this, the controller determines that the water heater whose communication has become inoperable has been turned off, stops combustion, and fully opens the hot water solenoid valve. Even though it was in the middle, there was a problem that cold water flowed out from the hot water tap.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a parallel type multiple water heater control method capable of preventing cold water from flowing out when the water heater falls into a communication disabled state.

[0006]

In order to achieve the above object, the parallel type water heater control method of the present invention comprises connecting at least two water heaters each having a water amount adjusting valve and a hot water discharge solenoid valve in parallel. In the parallel type multiple water heaters, when at least one water heater is in the hot water discharge operation, the hot water discharge solenoid valve of another water heater is opened to supply hot water when the required hot water discharge amount satisfies a predetermined increase condition. The number of operating water heaters is increased, and when the demand for hot water supply meets the predetermined reduction condition, one of the hot water heaters that is in operation closes the hot water solenoid valve and the number of operating water heaters is decreased. It becomes impossible to send and receive information between the system controller and the water heater, and the hot water supply solenoid valve of the water heater determined to be incommunicable is fully closed to control the number of units with other water heaters. Cold water flows out from the hot water tap It can be prevented.

[0007]

Embodiments of the present invention will be described with reference to the drawings.
In the present embodiment, three water heaters 1, 2, 3 are connected in parallel, and each water heater 1, 2, 3 has a heat exchanger 11, 12, 13 and a heat exchanger 11, respectively. Water inlets 21, 22, 23 connected to the inlet sides of 12, 13 and hot water outlets 31, 32, 33 connected to the outlet sides of the heat exchangers 11, 12, 13 and water inlets 21, 22, 23 And bypass paths 41, 42, 43 that connect the hot water passages 31, 32, 33 with each other
And burners 101, 102 for heating the heat exchangers 11, 12, 13,
It is equipped with 103 and.

In each water heater 1, 2 and 3, a bypass passage
41, 42, 43 downstream of the branch portion, that is, the heat exchangers 11, 12, 13
In the water inlets 21, 22, 23 on the inlet side, the can body water flow rate Q _K1 , Q _K2 ,
_Intake water amount sensors 51, 52, 53 for detecting Q _K3 are provided, and bypass water amount sensors 61, 62, 63 and bypass water amount Q for detecting bypass water amounts Q _B1 , Q _B2 , Q _B3 are provided in the bypass passages 41, 42, 43. Bypass valves 71, 72, 73 for adjusting _B1 , Q _B2 , Q _B3 are provided, and a hot water outlet passage 31, upstream of the junction of the bypass passages 41, 42, 43, that is, on the outlet side of the heat exchangers 11, 12, 13 is provided. 32 and 33 are provided with water flow control valves 81, 82 and 83 with an overflow prevention function, and hot water discharge valves 31, 32 and 33 are provided with hot water discharge solenoid valves 91, 92 and 93. Further, proportional control valves 111, 112, 113 are provided in the gas supply paths connected to the burners 101, 102, 103, respectively. The water inlets 21, 22, and 23 of each water heater 1, 2, and 3 are both connected to the original water supply passage 4, while the hot water outlets 31, 32, and 33 are both connected to the hot water supply passage 5 and are connected to the original water supply passage 4. An incoming water temperature sensor 6 for detecting the incoming water temperature Tc is provided.

The set temperature Ts, the water temperature Tc detected by the water temperature sensor 6, the can body water flow rates Q _K1 , Q _K2 , Q _K3 detected by the water flow rate sensors 51, 52 and 53, and the bypass water flow rate sensor.
Bypass water amounts Q _B1 , Q _B2 , Q _B3 detected by 61, 62, 63 are input to the controller 5, and a drive control signal is sent from the controller 7 to the bypass valves 71, 72, 73 and the over-flow prevention water amount adjustment. It outputs to the valves 81, 82 and 83, the hot water solenoid valves 91, 92 and 93 and the proportional control valves 111, 112 and 113.

Water flow control valve 81, 82, 83 with overflow prevention function
Is the water flow rate of the can bodies of each water heater 1, 2, 3 Q _K1 , Q _K2 , Q _K3
Is the maximum flow rate Qmax ₁ , Qmax ₂ , Qma of each water heater ₁ , ₂ , 3
x ₃ or more (Q _K1 ≧ Qmax ₁ , Q _K2 ≧ Qmax ₂ , Q _K3 ≧ Q
At max ₃ ), the opening is reduced for each, and the flow rate is reduced to prevent overflow independently of each other, while the can body water flow rate Q _K1 , Q _K2 , Q _K3 is the maximum flow rate Q max ₁ , respectively. Qma
x ₂ , less than Qmax ₃ (Q _K1 <Qmax ₁ , Q _K2 <Qmax ₂ , Q _K3 <
At the time of Qmax ₃ ), the openings of the can body water flow rates Q _K1 , Q _K2 , and Q _K3 are maintained. If the water flow resistances of the water heaters 1, 2, and 3 are equal in the state where the above-mentioned overflow prevention is not performed, the can body water flow rates Q _K1 , Q _K2 , and Q _{K3 of the} water heaters 1, 2, and 3 are equal.
Are equal to each other (Q _K1 = Q _K2 = Q _K3 ).

By-pass valves 71, 72 of each water heater 1, 2, 3
Reference numeral 73 denotes a target distribution ratio (Q _K1 / Q _B1 = 1 / α ₁ , Q 1) as a distribution ratio which is a ratio of the can body water flow rate Q _K1 , Q _K2 , Q _K3 and the bypass water quantity Q _B1 , Q _B2 , Q _{B3. K2} / Q _B2 = 1 / α ₂ , Q _K3
/ Q _B3 = 1 / α ₃ ), but in the present embodiment, α ₁ = α ₂ = α ₃ =
Let be α. From the set temperature Ts and the incoming water temperature Tc, the can set temperature Tks of each water heater 1, 2, 3 can be obtained by the following equation. T _KS = (1 + α) Ts −α · Tc For the purpose of preventing low temperature corrosion and boiling, the range of the can set temperature Tks is set (for example, 50
℃ ≤ Tks ≤ 80 ℃). Further, the can body set flow rate Q _KS is calculated by the following equation. Q _KS = (Gmax. × 25) / (T _KS -Tc) = Gmax ₁ / (T
_KS -Tc) where, Gmax. Maximum scale number of the water heater, Gmax ₁ is heat. Further, the total set flow rate Q _TS of each water heater is obtained by the following equation. _{Q TS = (Gmax. × 25} ) / (Ts -Tc) Further, in the flow velocity in the water passage of the water heater is likely to be eroded and becomes excessive, as well as pre-set total maximum flow Q _Tmax, the following Total minimum set flow rate Q according to the formula
_{Calculate TSmin} . _QTSmin. = (Gmin. * 25) / (Ts-Tc) where Gmin. Is the minimum number.

The number-of-units control operation will be described with reference to the flowchart of FIG. If the run switch is off,
Water flow control valve 81 with overflow prevention function for all water heaters 1, 2 and 3
82, 83 are fully closed, and hot water discharge solenoid valves 91, 92, 93 and bypass valves 71, 72, 73 are opened so that cold water can be used in the hot water tap. When the operation switch is turned on, it is confirmed that the communication state of the water heater 1 is normal, and the hot water outlet solenoid valve 91 of the water heater 1 is fully opened, and the water flow control valve 81 with an overflow prevention function and the bypass valve 71. The hot water supply operation of the hot water supply device 1 is started and the hot water supply solenoid valves 92 and 93 of the other hot water supply devices 2 and 3 are fully closed, that is, the hot water supply devices 2 and 3 are stopped. When the hot water supply device 1 is in a communication-disabled state due to a disconnection or the like, the hot water supply device 1 does not start the hot water discharge operation because the hot water discharge solenoid valve 91 is closed and the hot water supply device 2
When the hot water supply solenoid valve 92 is opened and the hot water supply device 2 starts the hot water supply operation, and the hot water supply device 2 is also unable to communicate, the hot water supply device 2
Also, the hot water discharge solenoid valve 92 is closed and the hot water discharge operation is not started, and the hot water discharge solenoid valve 93 of the water heater 3 is opened and the hot water supply device 3 starts the hot water discharge operation.

When only the hot water supply device 1 is in the hot water discharge operation, the overflow prevention water amount adjusting valve 81 prevents overflow, and the can body water flow rate Q _K1 becomes equal to the can body set flow rate Q _KS. With the target distribution ratio (Q _K / Q _B = 1 / α),
Hot water at the set temperature Ts is being discharged. When the amount of hot water discharged increases and at least one of the following conditions for increasing the number is satisfied, it is confirmed that the communication state of the water heater 2 is normal, and the hot water electromagnetic of the water heater 2 is checked. The valve 92 is opened to start the hot water supply operation of the water heater 2. When the hot water supply device 2 cannot communicate, the hot water supply solenoid valve 92 of the hot water supply device 2 is closed and the hot water discharge operation is not started, and the hot water supply solenoid valve 93 of the hot water supply device 3 is opened so that the hot water supply device 3 operates. Start hot water operation. [Increase condition] The can body water flow rate Q _K1 becomes 90% or more of the above can body set flow rate Q _KS (Q _K1 ≧ 0.9 · Q _KS ). The sum of the can body water flow rate Q _K1 and the bypass water flow rate Q _B1 is 90% or more of the above total set flow rate Q _TS {(Q _K1 + Q _B1 ) ≧ 0.9
・ Q _TS }. The sum of the can body water flow rate Q _K1 and the bypass water flow rate Q _B1 is 90% or more of the above total maximum flow rate Q _Tmax {(Q _K1 + Q _B1 ) ≧ 0.
9 · Q _Tmax }.

In the water quantity control valve 82 with the overflow prevention function of the water heater 2 that has started the hot water discharge operation, the can body water flow rate Q _K1 of the water heater 1 is a preset K times the can body set flow rate Q _KS (for example, K = 0.5
The opening is adjusted so that Hot water heater 2 at this time
The can body set flow rate Q _KS2 of Q _KS2 is Q _KS2 = Q _K2 − (Q _KS · K−Q _K1 ).

When the amount of hot water discharged further increases, the water flow rate adjusting valve 82 with overflow prevention function of the water heater 2 is opened so that the can body water flow rate Q _{K1 of} the water heater 1 does not exceed K times the set body flow rate Q _KS. The degree is adjusted, and the amount of hot water discharged from the water heater 2 increases.
In this state, when at least one of the above-mentioned increasing conditions is satisfied in the water heater 2, it is confirmed that the communication state of the water heater 3 is normal, and the hot water solenoid valve 93 of the water heater 3 is opened. The hot water supply operation of the water heater 3 is started, and at this time point, the water amount adjusting valve 82 with the overflow prevention function of the water heater 2 shifts to the overflow prevention operation. At this time, the water flow rate adjusting valve 83 with the overflow prevention function of the water heater 3 is opened so that the can body water flow rate Q _K2 of the water heater 2 becomes K times the can body set flow rate Q _KS (K = 0.5). Adjusted. The can body set flow rate Q _KS3 of the water heater 3 at this time is Q _KS3 = Q _K3 − (Q _KS · K−Q _K2 ). When the hot water supply device 3 is in a communication-disabled state, the hot water output solenoid valve 93 of the hot water supply device 3 remains closed and the hot water discharge operation is not started.

Next, the number reduction control in which the amount of hot water discharged decreases and the number of operating units decreases will be described. When the water heater 3 satisfies at least one of the following reduction conditions (the water flow rate of the can body Q _{K2 in the} water heater 2 is K times the can body set flow rate Q _KS ), the hot water of the water heater 3 is discharged. The solenoid valve 93 is closed, and the water flow rate adjusting valve 82 with overflow prevention function of the water heater 2 is set to the preset flow rate Q _KS of the can body water flow rate Q _{K1 of} the water heater 1 from the overflow prevention opening. The opening is adjusted to double (K = 0.5).

[Reduction Condition] The water flow rate Q _K3 is the minimum required water flow rate M of the water heater 3
It decreases below the sum of OQ _K and the water flow rate of a given body q _K (for example, 0.5 l / min.) (Q _K3 ≦ MOQ _K + q _K ). The sum of can body water flow rate Q _K3 and bypass water flow rate Q _B3 decreases below the sum of total minimum required water flow rate MOQ _{T of} water heater 3 and predetermined total required water flow rate q _T (eg, 1 l / min.). {(Q _K3 + Q _B3 ) ≦ (MOQ _T + q _T )}. The sum of the can body through water Q _K3 and the bypass water Q _B3 is the total minimum setting of the water heater 3 flow Q _Tsmin. And a predetermined total set flow rate q _TS (e.g., 1l / min.) Decreases below the sum of the { (Q _K3 + Q _B3 ) ≦ (Q _TSmin. + Q _TS )}.

Furthermore, when the amount of hot water discharged decreases and the water heater 2 satisfies at least one of the above reduction conditions (water heater 1
In this case, the can body water flow rate Q _K1 is ensured to be K times the can body set flow rate Q _KS ), and the hot water supply solenoid valve 92 of the water heater 2 is closed, and the water flow control valve 81 with the overflow prevention function of the water heater 1 is Continues the overflow prevention operation.

As described above, when increasing the number of operating water heaters, by controlling the flow rate of the water heater that starts the latest operation, the can body water flow rate Q _K of the water heater that has started operation before that is controlled. Maintaining a predetermined value or more (for example, controlling the flow rate of the water heater 3 to keep the can body water flow rate Q _K2 of the water heater 2 at least K times the can body set flow rate Q _KS ) to prevent deterioration of the hot water discharge characteristics. To do. Further, in the case of reducing the number of operating water heaters, when stopping the operation of the water heater that has recently started operation, by controlling the flow rate of the water heater that has started operation before that,
The can body water flow rate Q _K of the water heater that has started operation in front of the table is maintained at a predetermined value or more (for example, when the water heater 3 is stopped, the flow rate of the water heater 2 is controlled to control the water heater 1). Can body water flow Q
_K1 is kept at K times or more of the set value Q _KS of the can body), and the deterioration of the tapping property is prevented. Furthermore, since the communication state of the hot water supply device is always checked regardless of the number of times of increase, the outflow solenoid valve of the hot water supply device that is unable to communicate is fully closed to prevent the outflow of cold water regardless of the communication failure time.

In the above embodiment, the target distribution ratio α was set to be the same in all the water heaters, but they are all different (α
Naturally, ₁ ≠ α ₂ ≠ α ₃ ).
Further, in the above embodiment, the can body water flow rate Q _K or the total flow rate (that is, Q
_The number of units is controlled based on the fluctuation of ( _K + Q _B ).
The number of units may be controlled based on the fluctuation of the can body water flow rate Q _K or the total flow rate (that is, Q _K + Q _B ) of an arbitrary water heater.

As described above, in the parallel multiple water heater control method of the present invention, after confirming that the communication states of the respective water heaters 1, 2 and 3 are normal, the respective hot water solenoid valves 91 are provided. , 92, 93 are opened, and when one of the water heaters is unable to communicate, the hot water solenoid valve of the water heater that cannot communicate is closed and a hot water request is issued to the water heater that cannot communicate. In this case, since the operation of the other water heater is started, the cold water is not supplied from the water heater that cannot communicate.

[0023]

Since the present invention is constructed as described above, it has the following effects. After confirming that the communication status of each water heater is normal, each hot water outlet solenoid valve is opened, and when one of the water heaters cannot communicate, Close the hot water solenoid valve,
When a hot water supply request for a water heater that cannot communicate is made, the operation of another water heater is started, so that cold water is not supplied from the water heater that cannot communicate.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a parallel multiple water heater to which a parallel multiple water heater control method of the present invention is applied.

FIG. 2 is a flowchart of a method for controlling multiple water heaters in parallel according to the present invention.

[Explanation of symbols]

1, 2, 3 water heater, 4 yuan water supply channel, 5 hot water supply channel, 6
Inlet temperature sensor 7 Controller 11, 12, 13 Heat exchanger, 21, 22, 23 Inlet channel, 31, 32,
33 Hot water outlet 41, 42, 43 Bypass passage, 51, 52, 53 Inlet water flow sensor 61, 62, 63 Bypass water flow sensor, 71, 72, 73 Bypass valve 81, 82, 83 Overflow prevention water flow control valve, 91 , 92, 93
Hot water solenoid valve

Claims (1)

[Claims] 1. A number-of-units control for increasing or decreasing the number of operating units in parallel type water heaters in which at least two water heaters each having a water amount adjusting valve and a hot water discharge solenoid valve are connected in parallel, A method for controlling a plurality of parallel water heaters, characterized in that a hot water supply solenoid valve of a water heater determined to be incommunicable is fully closed, and the number of remaining water heaters is controlled.