JPH04254162A - Absorption type cold water/hot water machine and operation method thereof - Google Patents

Abstract

PURPOSE:To provide an absorption type cold/hot water machine which selects the optimum operation unit based on accumulated time of the operation and shutdown, efficiency, and economical performance of each unit of an absorption type refrigerating machine equipped with a plurality of absorption type cold and hot water unit. CONSTITUTION:The refrigeration capacity and holding water quantity of each absorption type cold/hot water unit is input into an operation control device. Based on the input values, the temperature of cold water after a specified time elapsed is predicted and each cold/hot water unit is operated in such a fashion that the temperature of cold/hot water may be constant after fixed time. This construction makes is possible to obtain an absorption type cold water/hot water machine capable of selecting the optimum operation unit from the accumulated time of operation and shutdown, efficiency, and economical performance of each unit.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type water chiller/heater and an operating method.

0002

BACKGROUND OF THE INVENTION In a conventional absorption type water chiller/heater, the number of operating chiller/heater units is determined by predicting the temperature after a certain period of time based on the temperature gradient of cold/hot water in the collective piping of the chiller/heater.

[0003] As this type of device, for example, a technique described in Japanese Patent Laid-Open No. 60-66077 is known.

0004

[Problem to be Solved by the Invention] The above conventional technology predicts the temperature in 10 minutes, for example, based on the current temperature and gradient, and if it is determined that the predicted temperature will be 7.5°C or lower (below the specification/range), the number of operating units will be reduced. was decreasing.

However, no consideration is given to the cooling capacity of the newly installed water chiller/heater, and if the cooling capacity is different, the chilled/hot water temperature after the operation is stopped may vary, for example, if a unit with low cooling capacity is stopped. In some cases, the temperature gradient does not change much and the next unit may be shut down immediately.

Furthermore, when a unit with a high cooling capacity is stopped, the temperature of the cold water may rise again.

[0007] Therefore, there was a possibility that the operating units would not be stable and the number of operating units would be hunting.

Furthermore, the conventional technology does not take into account the operation time and stop time of each unit, and the operation time of one unit is extremely short, resulting in variations in operation time depending on the unit, which shortens the life of the unit. There was a risk of causing variations.

An object of the present invention is to manage the cooling capacity, operating time, and stop time of each unit of an absorption type chilled/hot water machine having a plurality of absorption type chilled/hot water units, and to determine which absorption type chilled/hot water units are operated or not. By considering all the combinations of what happens to the chilled water temperature when the unit is stopped, it is possible to select the optimal operating unit based on the cumulative operating and stopping time of each unit, efficiency, and economical efficiency. An object of the present invention is to provide an absorption type water chiller/heater and an operating method.

0010

[Means for Solving the Problems] The above object is to provide a temperature detector that detects the temperature of a collecting section of cold and hot water discharged from each absorption type cold and hot water unit, and a cooling capacity and an air conditioning system of each absorption type cold and hot water unit. and an operation control device into which the amount of water held is input, and this operation control device inputs the temperature of the cold and hot water in the collecting section, the refrigeration capacity of each absorption type cold and hot water unit, the amount of water held, and the operation of each absorption type cold and hot water unit. This is achieved by issuing operation and stop commands so that the operation and stop times of each absorption type cold/hot water unit are averaged based on the cumulative stop time.

[0011] Also, the above object is to provide a temperature detector for detecting the temperature of a collection part of cold and hot water discharged from each absorption type cold and hot water unit;
and an operation control device into which the refrigerating capacity of each absorption type cold/hot water unit and the amount of water held in the air conditioning system are input, and this operation control device inputs the temperature of the cold/hot water in the collecting section and the refrigerating capacity of each of the absorption type cold/hot water units. This is achieved by instructing each of the absorption type cold/hot water units to operate or stop based on the amount of water and the amount of water held.

0012

[Operation] The temperature of the cold and hot water collecting section is detected by a temperature detector, and the operation control device predicts the temperature of the cold water after a certain period of time based on the detected temperature, the cooling capacity of each unit, and the amount of water held. At this time, temperature prediction is performed for all combinations of operation and stop of each unit.

[0013] Since the operating unit is determined by predictive control in consideration of the predicted temperature and the operation time and stop time of each unit, there is no variation in the cumulative operation and stop time of each unit, and efficiency and economical efficiency are taken into consideration. The operating unit can be selected.

[0014]

[Embodiment] An embodiment of the present invention will be explained below with reference to FIG.

[0015] The figure is a system diagram of an absorption type water chiller/heater.
Reference numerals 1 to 23 denote cold and hot water units equipped with a refrigeration cycle, which cool the hot water sent by the cold and hot water pumps 61 to 63 during cooling, and heat and send it out during heating. Also 7
1 to 73 are check valves.

Reference numeral 11 denotes a feed pipe that guides the cold and hot water sent out from the cold and hot water units 21 to 23 to the load 5;
1 is provided with a thermistor 3 that detects the temperature of a collection part of the delivered cold and hot water. Further, reference numeral 12 is a return pipe that guides cold and hot water from the load 5 to the cold and hot water units 21 to 23.

Reference numeral 1 denotes an operation control device that controls the operation of the cold and hot water units 21 to 23 according to the operating status of the cold and hot water collection part thermistor 3 and each of the cold and hot water units 21 to 23, and has the configuration shown in FIG. .

The operation control device 1 includes an analog/digital (A/D) converter 8 that converts an analog signal from the thermistor 3 provided at the cold/hot water collection part of the pipe 11 into a digital input, and cold/hot water units 21 to 3. 23 and signal lines 41-43
A microcontrol unit (hereinafter referred to as a microcontrol unit) having a serial communication function 9 that communicates via 15 (referred to as MCU) is installed.

That is, the temperature of the cold and hot water collecting section is measured by the thermistor 3, and this is A/D converted, and the MCU 15
to be memorized. Communication is also performed by switching the signal lines 41 to 42 to each of the cold and hot water units 21 to 23. Regarding the communication content, the operation control device 1 transmits operation and stop commands to each of the cold and hot water units 21 to 23, and receives operation, combustion, etc. from the cold and hot water units 21 to 23. In addition, the operating time and stop time of each unit 21 to 23 obtained through communication are obtained by the MCU 14.
The time is managed using a timer.

Furthermore, the number control device 1 has a DiP switch 10 that controls the cooling capacity Q of each cold/hot water unit 21 to 23.
1, Q2, Q3 and the amount of water held in the cooling system (heat capacity)
C is input to the MCU 14. The MCU 14 also has various calculation functions.

In the operation control device 1, the temperature gradient (dT/dt) is calculated by the MCU 13 every unit time based on the temperature of cold and hot water taken in by the thermistor 3. Here, T is cold and hot water, and temperature.

Furthermore, the quantity QOUT of the load 5 is estimated using the input water quantity C of the system using the following equation.

[0023]

[Math 1]

[0024] Here, QR is the total amount of heat of the cold/hot water machines 21-23. As shown in Fig. 3, the units 21 to 23 of the absorption type water chiller/heater have a cooling capacity of 100% after starting operation.
%, and there is also a time delay after receiving a stop command and entering the stop operation until the cooling capacity is exhausted. Therefore, the total amount of heat QR of the cold/hot water units 21 to 23 is equal to each cold temperature at that point. The total refrigerating capacity of the water units 21 to 23 is calculated and determined.

Next, regarding each operation pattern shown in FIG.
Total amount of heat Q of cold/hot water units 21 to 23 after a certain period of time
R is calculated, and the cold/hot water temperature T1 after a certain period of time is determined by the following formula.
Calculate and find.

[0026]

[Math 2]

[0027]

[Math 3]

Next, when determining the operation of any of the cold/hot water units 21 to 23, the operation time, stop time, and cold water temperature T1 after a certain period of time of each unit are determined as shown in FIGS. 5 to 7. .

That is, the evaluation of driving time is divided into three categories, short, moderate, and long, depending on the driving time, and each evaluation is made into a continuous function from 0 to 1, and the degree of conformity to each evaluation is determined based on the driving time. In the function, 1 means 100% fitness, and 0 means 0% fitness. For example, if the driving time is 12 minutes, the degree of conformity to the evaluation of ``short driving time'' is 0.6, and the degree of conformity to the evaluation of ``appropriate driving time'' is 0.35.

Similarly, the evaluation of the stop time of each unit and the evaluation of the cold water temperature after a certain period of time are taken as shown in FIG. With this function, evaluations such as "time is short" and "temperature is high" can be expressed using degrees in the [0,1] interval.

Furthermore, control rules are defined as follows.

[0032] Here, we will take as an example a case where the unit 21, the unit 22, and the operation unit 23 are stopped during cooling.

Rule 1: If the chilled water temperature is high even if unit 23 is operated, unit 23 is operated and units 21 to 21 are operated.
23 is considered to be driving.

Rule 2: If the unit 23 is stopped for a long time and the units 21 to 23 are in operation and the chilled water temperature is appropriate, the unit 23 is operated.

Rule 3: If unit 21 and unit 2
If the chilled water temperature is suitable during operation 2, continue operation.

Rule 4: If the operation time of the unit 22 is long, the stop time of the unit 23 is appropriate, and the chilled water temperatures of the units 21 and 23 are appropriate, then the units 21 and 23 are set to be operated.

Rule 5: If the operation time of unit 21 is long and the stop time of unit 23 is appropriate, and the chilled water temperatures in units 22 and 23 are appropriate, then units 22 and 23 are operated.

Rule 6: If the operating time of unit 22 is long and the chilled water temperature is appropriate when operating unit 21, unit 2
Stop 2.

Rule 7: If the operating time of unit 21 is long and the chilled water temperature is appropriate during operation of unit 22, unit 1 is stopped.

[0040] For the above rules 1 to 7, Min-Max
The number of machines is controlled using the rules that are highly evaluated according to the law as control rules.

That is, the evaluation fitness of each function is determined in the "if" part (antecedent part). The minimum value of evaluation suitability is found for each rule, and this is taken as the evaluation value of that rule. Next, the rule with the maximum evaluation value of each rule is adopted as the control rule.

For example, the temperature of cold and hot water after a certain period of time is as shown in FIG. Consider the case of First, find the evaluation value of each rule.

Rule 1: When the units 21 to 23 are operated, the chilled water temperature is 7.0°C, and the evaluation suitability of the chilled water temperature is 0.

Rule 2: The stop time of the unit 23 is 17 minutes, and the evaluation suitability for "long stop time" is 0, and the evaluation suitability for cold water temperature appropriateness when operating 3 units is 0, so the minimum value is 0.

Rule 3: Unit 21 and unit 22 are operated at 7.5°C, and the evaluation suitability for chilled water temperature is 0.5.
.

Rule 4: When the operating time of the unit 22 is 22 minutes, the evaluation conformity to the operating time length of the unit 22 is 0.4.
, the evaluation suitability for Unit 3 shutdown time suitability was 0.6, and the evaluation suitability for chilled water temperature suitability was 0.5 at a chilled water temperature of 7.5°C.

∴The evaluation value of rule 4 is 0.4.

Rule 5: The evaluation suitability of the operating time length of the unit 21 is 0.

[0049] Evaluation suitability of stop time of unit 23 is 0
．． 6.

Evaluation of cold water temperature suitability: 1.0.

∴Evaluation value of rule 5 is 0.

Rule 6: The evaluation suitability of the operating time length of the unit 22 is 0.4.

Evaluation of cold water temperature suitability: 0.5.

∴The evaluation value of rule 6 is 0.4.

Rule 7: The evaluation suitability of the operating time length of the unit 21 is 0.

Evaluation of cold water temperature suitability: 0.5.

∴The evaluation value of rule 7 is 0.

Next, the rule with the highest evaluation value of each rule is set as the control rule.

In this example, the evaluation value of rule 3 is 0.5.
Since this is the maximum, the operation of unit 21 and unit 22 is maintained.

As explained above, according to this embodiment, even if the cooling capacity of the installed water chillers/heaters differs, the chilled water temperature can be stabilized and the operating time of the machines can be smoothed, and the optimal number of units can be controlled. There is an effect that can be done.

[0061]

[Effects of the Invention] According to the present invention, since the cooling capacity of each unit is recognized, it is possible to judge which unit to select even if the cooling capacity of the installed water cooler/heater is different, and each unit Since the cumulative operating and stopping time of the system is averaged, the service life of the system is improved, and an efficient and economical absorption type water chiller/heater can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the present invention.

FIG. 2 is an installation diagram of an operation control device.

FIG. 3 is a diagram showing the relationship between unit operating time and cooling capacity.

FIG. 4 is an explanatory diagram of an operation pattern of the unit.

FIG. 5 is a diagram showing the relationship between unit operation time and evaluation.

FIG. 6 is a diagram showing the relationship between unit stop time and evaluation.

FIG. 7 is a diagram showing the relationship between cold water temperature and evaluation after a certain period of time.

[Explanation of symbols]

1...operation control device, 3...cold/hot water collection part thermistor, 5...
Load, 15...MCU, 21-23...Absorption type cold/hot water machine unit, 41-43...Communication line, 61-63...Cold/hot water pump.

Claims (4)

[Claims] 1. An absorption type cold/hot water machine equipped with a plurality of absorption type cold/hot water units, comprising: a temperature detector for detecting the temperature of a collecting section of cold/hot water discharged from each absorption type cold/hot water unit;
and an operation control device into which the refrigerating capacity of each absorption type cold/hot water unit and the amount of water held in the air conditioning system are input, and this operation control device inputs the temperature of the cold/hot water in the collecting section and the refrigerating capacity of each of the absorption type cold/hot water units. An absorption type cold/hot water machine characterized in that an instruction to operate or stop each absorption type cold/hot water unit is issued based on the amount of water stored in the water supply unit and the amount of water held. 2. An absorption type cold/hot water machine equipped with a plurality of absorption type cold/hot water units, comprising: a temperature detector for detecting the temperature of a collecting section of cold/hot water discharged from each absorption type cold/hot water unit;
and an operation control device into which the refrigeration capacity of each absorption type cold/hot water unit and the amount of water held in the air conditioning system are input, and this operation control device controls the temperature of the cold/hot water in the collection area and the refrigeration of each absorption type cold/hot water unit. Based on the capacity, the amount of water held, and the cumulative operation/stop time of each absorption type cold/hot water unit, commands for operation/stop are issued so that the operation/stop time of each absorption type cold/hot water unit is averaged. Features: Absorption type water chiller/heater. 3. A method of operating an absorption type chiller/heater equipped with a plurality of absorption type chilled/hot water units, wherein the temperature of the cold/hot water gathering part of each absorption type chilled/hot water unit and the temperature of the cold/hot water collection part of each absorption type chilled/hot water unit are determined. A method of operating an absorption type chilled/heated water machine characterized by combining the operation and stop of each absorption type chilled/hot water unit based on the refrigeration capacity and the amount of water held in the cooling/heating system. 4. A method of operating an absorption chiller/heater equipped with a plurality of absorption chiller/hot water units, wherein the temperature of the cold/hot water collection part of each absorption chiller/hot water unit and the Combining each absorption chilled/hot water unit so that the operation and stop times of each absorption chilled/hot water unit are averaged based on the refrigeration capacity, the amount of water held in the cooling/heating system, and the cumulative operation and time of each absorption chilled/hot water unit. A method of operating an absorption type water chiller/heater, characterized by: