JP2827923B2 - Backup control method in case of temperature detector failure in fluid number control 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 plurality of fluid heaters such as a hot water boiler, a heat medium boiler, a heat exchanger, and an absorption refrigerator.
The present invention relates to a method for controlling the number of fluid heaters to be installed and automatically controlling the number of operating fluid heaters according to a load condition.

[0002]

BACKGROUND OF THE INVENTION hot water boiler installed multiple units in parallel, is this
Units control system of the hot water boiler so as to automatically controlled in accordance with number of operating et hot water boiler load conditions are implemented. The system for controlling the number of hot water boilers, compared to installing one large capacity hot water boiler,
Since each hot water boiler can be operated with high efficiency, it has a remarkable effect on energy saving and has an advantage that it has excellent responsiveness to load fluctuations.

[0003]

In THE INVENTION to be solved INVENTION upper mentioned hot water boiler of the platform <br/> speed control system, in order to increase or decrease the number of operating the hot water boiler, the hot water temperature of individual hot water boiler, the supply to the load Temperature parameters such as the temperature and the return temperature from the load are important, but if the temperature detector that detects these temperatures fails (wire breaks, etc.) , the operation of the system must be stopped. Will also stop. Disruption of the supply of hot water causes the production line of the factory that uses it to be shut down, causing enormous damage.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and in a system for controlling the number of fluid heaters such as hot water boilers, when one temperature detector fails, another temperature detection is performed. It is an object of the present invention to enable continuous operation without stopping the system by substituting the value detected by the detector. Chi words, the present invention is to install a plurality of fluid heater in parallel, and a load with these fluid heating device connected with the fluid supply passage and a fluid return path, the number of operating the fluid heater of the load In the system for controlling the number of fluid heaters controlled according to the situation, the return temperature Ti of the fluid in the fluid return path is detected, and the average value T _BX ′ of the outflow temperature T _BX of the fluid from each fluid heater is determined. Calculated, based on the return temperature Ti and the average value T _BX ′, increase or decrease the number of permitted operation of the fluid heater, and when the return temperature detector for detecting the return temperature Ti fails, the outflow temperature T It is characterized in that the minimum value of _BX is used instead of the return temperature Ti. Also,
The present invention is characterized in that when the outflow temperature detector for detecting the outflow temperature _TBX fails, the supply temperature To of the fluid in the fluid supply path is used instead of the average value _TBX '.

[0005]

The present invention detects the return temperature Ti of the fluid in the fluid return path, calculates the average value T _BX ′ of the outflow temperature T _BX of the fluid from each fluid heater, and calculates the return temperature Ti and the average value T _BX ′. Based on the value T _BX ′, the number of permitted operation of the fluid heater is increased or decreased. When the return temperature detector for detecting the return temperature Ti fails, the outflow temperature T _BX is determined.
Is used in place of the return temperature Ti, and when the outflow temperature detector for detecting the outflow temperature _TBX fails, the supply temperature To of the fluid in the fluid supply path To
_Is used in place of the average value T _BX ′ to continue the operation without stopping the system.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. The system for controlling the number of fluid heaters shown in FIG.
A plurality of fluid heaters 1 are installed in parallel, and these fluid heaters 1 and the load 2 are connected to a fluid supply path 3 and a fluid return path 4.
In connecting, so as to control accordingly the number of operating fluid heating device 1 to the situation of the load 2. Each of the fluid heaters 1
For example, a hot water boiler, a heat medium boiler, a heat exchanger, an absorption refrigerator, or the like is applied. A circulation pump 5 is inserted in the fluid return path 4. This circulation pump 5 can be inserted into the fluid supply path 3.

[0007] The fluid supply path 3 is provided with a supply temperature detector 6 for detecting a supply temperature To of the fluid. The fluid return path 4 has a fluid return temperature T.
A return temperature detector 7 for detecting i is provided. Further, to the each fluid heating device 1, the outlet temperature detector 9 for detecting the outflow temperature T _BX of the fluid from the fluid heating apparatus 1, respectively. Based on signals from these temperature detectors 6, 7, 9, and the control procedure preset by luck <br/> rolling quantity control device 8 of the fluid heater
There has been so as to control me. Each in fluid heater 1 are preset priority, respectively, was prepared in this priority the operation of the fluid heating device 1 is controlled me. The priority is set so that rotation is performed appropriately so that the operation time of each fluid heater is averaged.

Next, an embodiment of a specific number control method will be described. First, it was prepared in the following formula to calculate the <br/> operation permission number N of the fluid heater I, and outputs only the operation permission number N min operation permission signal the to the fluid heating apparatus 1. N = M × (To _SET− Ti) / (T _B −Ti) M: Total number of fluid heaters 1 To _SET : Set temperature of fluid in fluid supply path 3 Ti: Return temperature of fluid in fluid return path 4 T _B: set temperature of the fluid heating device 1 and, from N base fluid heating apparatus 1 which has received the operation permission signal is out fluid heated to a set temperature T _B, the remaining M-N base fluid heater since the outflow remained temperature Ti return fluid that has returned through the fluid return path 4 from 1, it is possible to obtain the operation permission number N from the above equation based on the heat balance of the entire system.

As the number N of permitted operations, a value obtained by truncating the decimal part is used. Fluid heater 1 which received operation permission signal
Cormorants Although the actual ON-OFF of the set value set for each fluid heater 1. Chi words, each fluid heating device 1, its
Internal heating of the fluid when the fluid temperature T has reached the set temperature T _B is stopped, De fluid temperature T is higher than the set temperature T _B I of
Starting heating of the fluid when lowered only full Arensharu value [Delta] T _B min. Thereby, overshoot with respect to the set value of the fluid supply temperature To at the time of the initial startup can be effectively reduced.

Next, based on the average value T _BX ′ of the outflow temperature T _BX of the fluid from each fluid heater 1, if the average value T _BX ′ is within a preset range, the current permitted number of operation is determined. When the average value T _BX ′ falls below a preset range, the number of permitted vehicles is increased, and when the average value T _BX ′ exceeds a preset range, the number of permitted vehicles is reduced. The determination of the increase or decrease in the number of permitted operation units is performed at predetermined time intervals (for example, every 10 seconds), and the increase or decrease in the number of permitted operation units is performed one by one. The above-mentioned preset range is a range in which the set temperature To _SET of the fluid in the fluid supply path 3 is set as an upper limit value, and a value obtained by subtracting ΔTw (for example, about 5 ° C.) from the set temperature To _{SET is} set as a lower limit value. . ΔT
When in w has a value of the supply temperature To, by maintaining the current number of operating, to prevent the unnecessary start-stop of the fluid heating apparatus 1, it is possible to stabilize the supply temperature To .

The return temperature Ti is detected by a return temperature detector 7 provided in the fluid return path 4. When the return temperature detector 7 fails (such as disconnection), the fluid heater 1
Of the outflow temperature _TBX detected by the outflow temperature detector 9 is used instead of the return temperature Ti. Further, the average value T _BX ′ is determined by an outflow temperature detector 9 provided in the fluid heater 1.
When the outflow temperature detector 9 fails (such as a disconnection), the supply temperature To of the fluid detected by the supply temperature detector 6 provided in the fluid supply path 3 is calculated.
_Is used instead of the average value T _BX ′. in this way,
When a certain temperature detector fails, the value detected by another temperature detector is substituted, thereby enabling continuous operation without stopping the system. Then, a time zone in which there is no problem even if the system is stopped is estimated, and the failed temperature detector is repaired or replaced.

As a specific number control method, the following number control method can be adopted in addition to the above-described method. First, the return temperature T of the fluid in the fluid return path 4
i is compared with the lower limit value To _SET -ΔTw of the set temperature range of the fluid in the fluid supply path 3, and Ti> To _SET -ΔT
If it is w, the current permitted number of operation is reduced by one, and Ti ≦
If To _SET -ΔTw, the fluid heating capacity T _B ′ of the fluid heater 1 is obtained as follows. Based on the operating license number N determined from the above equation mentioned, N = 0 if X = T _B Max
If N ≧ 1, X = Ti + − (To _SET− ΔT
w) −Ti｝ × M / N, fluid heater 1 at that time
Determines the value of the temperature X that can be supplied. Here, since the supply temperature is limited by the stop temperature of the fluid heater 1, X
> T _B Max value, T _B ′ = T _B Max value, X ≦ T _B Max
If the value T _B '= T _B - the differential value [Delta] T _B / 2 of the fluid heater.

[0013] Next, based on the fluid heating capacity of the fluid heating apparatus 1 of the above mentioned T _B ', obtains the first operation permission number Ma and the second operation permission number Mb from the following formula. _{Ma = M × (To SET -Ti} ) / (T B '-Ti) Mb = M × (To SET -ΔTw-Ti) / (T B' -Ti) M: total number of fluid heating device 1 the To _SET: setting of the fluid in the fluid supply channel 3 temperature range between the upper limit value to _sET -ΔTw: the lower limit of the set temperature range of the fluid in the fluid supply path 3 Ti: fluid return return temperature T of the fluid in the path 4 _B ': fluid heating apparatus 1 Fluid heating capacity

[0014] on the first operation permission number Ma and the second operation permission number Mb predicate, a value obtained by truncating decimals. And the outflow temperature T _BX of the fluid from each fluid heater 1
When the average value T _BX ′ is less than a preset range, the current permitted number of operation Mo is compared with the first permitted number of operation Ma and the second permitted number of operation Mb obtained from the above equation, and Mo> Ma
When Mb <Mo ≦ Ma, the current number of permitted machines is maintained, and when Mo ≦ Mb, the number of permitted machines is increased by one. Further, when the average value T _BX ′ is within a preset range, the current permitted operation number Mo is compared with the first permitted operation number Ma and the second permitted operation number Mb obtained from the above equation, and Mo> Ma When the number of operation permission is 1
The number of permitted vehicles is maintained when Mb ≦ Mo ≦ Ma, and the number of permitted vehicles is increased by one when Mo <Mb. Further, when the average value T _BX ′ exceeds a preset range, the number of operating units is reduced by one.

The above-described calculation of the first permitted number Ma and the second permitted number Mb is based on the calculation of each temperature in consideration of the time delay until the fluid supplied from the fluid heater 1 is mixed almost uniformly. The detection is performed after a lapse of the set delay time T _DERAY from the detection. According to the configuration of the above mentioned, it is possible to quickly detect a change in supply temperature in the change, such as circulation flow, it is possible to greatly improve the response to load variations.

The return temperature Ti is detected by a return temperature detector 7 provided in the fluid return path 4. When the return temperature detector 7 fails (such as disconnection), the fluid heater 1
Of the outflow temperature _TBX detected by the outflow temperature detector 9 is used instead of the return temperature Ti. Further, the average value T _BX ′ is determined by an outflow temperature detector 9 provided in the fluid heater 1.
When the outflow temperature detector 9 fails (such as a disconnection), the supply temperature To of the fluid detected by the supply temperature detector 6 provided in the fluid supply path 3 is calculated.
_Is used instead of the average value T _BX ′. in this way,
When a certain temperature detector fails, the value detected by another temperature detector is substituted, thereby enabling continuous operation without stopping the system. Then, a time zone in which there is no problem even if the system is stopped is estimated, and the failed temperature detector is repaired or replaced.

[0017]

The present invention has the above configuration,
When the return temperature detector that detects the return temperature Ti in the fluid return path fails, the outflow temperature T _{BX of the} fluid heater
Is used in place of the return temperature Ti, and when the outflow temperature detector for detecting the outflow temperature _TBX of the fluid heater fails, the supply temperature To of the fluid in the fluid supply path is used as the outflow temperature of the fluid heater. By using the average value T _BX ′ of the temperature T _BX instead of the average value, it is possible to continue the operation without stopping the system. It was although I, prevents the failure of the temperature detector stops the system due to heating fluid can be stably supplied, practically, it is extremely effective.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid heater 2 Load 3 Fluid supply path 4 Fluid return path 5 Circulation pump 6 Supply temperature detector 7 Return temperature detector 8 Control device 9 Outflow temperature detector

Claims (2)

(57) [Claims] 1. A plurality of fluid heaters 1 are installed in parallel, these fluid heaters 1 and a load 2 are connected by a fluid supply path 3 and a fluid return path 4, and the number of operating the fluid heaters 1 is reduced. In the system for controlling the number of fluid heaters controlled according to the condition of the load 2, the return temperature Ti of the fluid in the fluid return path 4 is detected, and the outflow temperature T _BX of the fluid from each of the fluid heaters 1 is detected. 'is calculated, and these return temperature Ti and the average value T _BX' mean T _BX make changes in working permitted number of the fluid heating device 1 based on, the return temperature detector 7 that detects the return temperature Ti A backup control method when a temperature detector fails in a system for controlling the number of fluid heaters, wherein a minimum value of the outflow temperature _TBX is used in place of the return temperature Ti when a failure occurs. 2. A plurality of fluid heaters 1 are installed in parallel, these fluid heaters 1 and a load 2 are connected by a fluid supply path 3 and a fluid return path 4, and the number of operating fluid heaters 1 is reduced. In the system for controlling the number of fluid heaters controlled according to the condition of the load 2, the return temperature Ti of the fluid in the fluid return path 4 is detected, and the outflow temperature T _BX of the fluid from each of the fluid heaters 1 is detected. An average value T _BX ′ is calculated, the number of permitted operation of the fluid heater 1 is increased or decreased based on the return temperature Ti and the average value T _BX ′, and an outflow temperature detector 9 for detecting the outflow temperature T _BX. Backup control method when the temperature detector fails in the fluid heater number control system, in which the supply temperature To of the fluid in the fluid supply path 3 is used in place of the average value T _BX ′ when a failure occurs. .