JP6078898B2 - Absorption system - Google Patents

Description

  The present invention relates to an absorption system including a plurality of absorption refrigerators.

  Conventionally, in an absorption system equipped with a plurality of absorption chillers, the cooling load is judged from the temperature difference between the cold / hot water set temperature (target temperature) and the cold / hot water inlet temperature and the flow of the cold / hot water for energy saving measures. A device that controls the number of operating absorption refrigerators is known (for example, see Patent Document 1). Moreover, in one absorption chiller, cold / hot water generated by the absorption chiller is performed by performing cold / hot water variable flow control that controls the flow of cold / hot water according to the ratio of the cooling load (burner heating amount). The thing which realized the energy saving of the cold / hot water pump which supplies water to a heat load is known (for example, refer patent document 2).

JP 2010-255880 A Japanese Patent Laid-Open No. 4-80567

By the way, in order to implement further energy saving measures, it is desired to combine the two unit control and the cold / hot water variable flow rate control.
However, in the cold / hot water variable flow rate control, since the cold / hot water inlet temperature is kept constant, it has been impossible to combine the number control for controlling based on the cold / hot water inlet temperature.
This invention is made | formed in view of the situation mentioned above, and it aims at providing the absorption type system which can use unit number control and cold / hot water flow rate control together.

In order to achieve the above object, the present invention includes a plurality of absorption chillers including a regenerator, a condenser, an evaporator, and an absorber, and a central control device that centrally controls the plurality of absorption chillers. In each of the absorption refrigeration systems, each absorption chiller is controlled by a variable frequency so as to control a flow rate of cold / hot water in an evaporator provided in the absorption chiller, and a cold / hot water inlet temperature of the cold / hot water. And a control device that controls the frequency of the cold / hot water pump so that the absorption refrigeration load during operation of the absorption chiller load of the absorption chiller during operation is maintained. Calculate from the difference between the cold / hot water inlet temperature of the evaporator and the cold / hot water outlet temperature of the evaporator and the flow rate of the cold / hot water, calculate the absorption system load from this absorption chiller load, Depending on the luck of the absorption refrigerator To increase or decrease the number, the despite the increase or decrease of the number of operating absorption the absorption refrigerator according to the system load, the predetermined time continues hot and cold water outlet temperature of the absorption refrigerator in operation is less than the predetermined temperature during cooling In this case, when the cold / hot water outlet temperature of the absorption chiller during operation is kept below a predetermined temperature for a predetermined time during heating, the number of operating absorption chillers is increased.

  The said structure WHEREIN: The said centralized control apparatus may control the operation number of the said absorption refrigerator according to the ratio of the refrigerating capacity at the time of 100% load.

  In the above configuration, the centralized control device may increase the number of operating absorption chillers when the absorption system load becomes equal to or higher than a predetermined load for a predetermined time.

  In the above configuration, each absorption refrigerator includes a high-temperature regenerator and a low-temperature regenerator as the regenerator, and the central control device has a high-temperature regenerator temperature of the absorption refrigerating machine that is a predetermined temperature for a predetermined time or more. In this case, the number of operating absorption chillers may be increased.

  In the above configuration, each absorption chiller includes a high-temperature regenerator and a low-temperature regenerator as regenerators, and the central control device is configured such that when the absorption system load exceeds a predetermined load for a predetermined time, or When the high-temperature regenerator temperature of the absorption chiller reaches a predetermined temperature for a predetermined time or more, the number of operating the absorption chillers may be increased.

  According to the present invention, the central control device calculates the absorption system load from the absorption refrigerator load of the operating absorption refrigerator, and controls the number of absorption refrigerators in accordance with the absorption system load. Therefore, unit control and cold / hot water flow rate control can be used in combination, and further energy saving can be realized.

It is a circuit diagram which shows the absorption refrigerator which concerns on embodiment of this invention. It is a block diagram which shows an absorption system typically. It is a figure which shows a number control table. It is explanatory drawing which shows an example of the number control of an absorption system. It is explanatory drawing which shows the other example of the number control of an absorption system.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a circuit diagram showing an absorption refrigerator according to the present embodiment.
The absorption refrigerator 100 is a double-effect absorption refrigerator using, for example, water as a refrigerant and a lithium bromide (LiBr) solution as an absorption liquid. This absorption refrigerator 100 has a high temperature regenerator 1, a low temperature regenerator 2, a condenser 3, an evaporator 4, an absorber 5, a high temperature heat exchanger 6, a low temperature heat exchanger 7 and the like connected by piping, And a refrigerant circulation cycle.

  Connected to the high-temperature regenerator 1 is a diluted liquid pipe 20 that guides a diluted absorbent (hereinafter referred to as a diluted liquid) in which the refrigerant is absorbed into the absorbent by an absorbent pump 11 from the absorber 5. In the high-temperature regenerator 1, a rare liquid guided from the absorber 5 through the rare liquid pipe 20 by the absorbent liquid pump 11 is accommodated, and a liquid level detector 15 for detecting the liquid level of the rare liquid is provided. Is provided. This rare liquid is heated by, for example, a burner 8 using city gas as fuel. The burner 8 includes an igniter 9 that ignites the fuel, and a fuel control valve 10 that controls the amount of fuel and makes the amount of heat source variable. The high temperature regenerator 1 is provided with an exhaust pipe 16 for exhausting exhaust gas.

  The high-temperature regenerator 1 is also provided with a refrigerant vapor pipe 21 that guides the refrigerant vapor generated by heating the dilute liquid to the condenser 3, and an intermediate liquid whose concentration has been increased by separating the refrigerant vapor at a low temperature. An absorption liquid pipe 22 leading to the vessel 2 is connected. The refrigerant vapor pipe 21 is branched into a first refrigerant vapor pipe 21A and a second refrigerant vapor pipe 21B. The first refrigerant vapor pipe 21A is connected to the condenser 3 via the low-temperature regenerator 2 as a heat transfer pipe. Yes. The second refrigerant vapor pipe 21 </ b> B includes an on-off valve 31 and is connected to the absorber 5. The absorption liquid pipe 22 is branched into a first absorption liquid pipe 22A and a second absorption liquid pipe 22B, the high temperature heat exchanger 6 is provided in the first absorption liquid pipe 22A, and the second absorption liquid pipe 22B is an on-off valve. 32 and connected to the absorber 5.

  The low temperature regenerator 2 is provided with an eliminator 36 for allowing the refrigerant vapor generated by heating the intermediate liquid by the refrigerant vapor flowing through the first refrigerant vapor pipe 23 </ b> A to flow into the condenser 3. Yes. The low temperature regenerator 2 is connected to an absorption liquid pipe 23 that guides the concentrated absorption liquid (hereinafter referred to as a concentrated liquid) from which the refrigerant vapor has been separated to the absorber 5. The absorption liquid pipe 23 includes a low-temperature heat exchanger 7 and is connected to a spreader 5 </ b> A provided at an upper portion in the absorber 5.

The condenser 3 is connected to a refrigerant pipe 25 extending from the lower part of the condenser 3 to the evaporator 4 and having a U-shaped portion in the middle, and flows down through the refrigerant pipe 25 by the action of gravity. The liquid refrigerant inside flows into the evaporator 4. In the condenser 3, a cooling water pipe 26 through which the cooling water flows is arranged as a heat transfer pipe.
The evaporator 4 is formed with a refrigerant reservoir 4B in which the refrigerant flowing in from the condenser 3 is accumulated, and a refrigerant pipe including a refrigerant pump 12 that circulates the liquid refrigerant from the refrigerant reservoir 4B to the sprayer 4A provided in the upper part. 27 is connected. In the evaporator 4, a cold / hot water pipe (supply pipe) 28 is disposed as a heat transfer pipe, and the brine (for example, cold water or hot water) is supplied through the cold / hot water pipe 28 to a heat load 300 (for example, an air conditioner) (FIG. 2). ).

The inside of the evaporator 4 and the absorber 5 is maintained at a high vacuum. The evaporator 4 and the absorber 5 are partitioned by a partition wall 37A. On the partition wall 37A, the refrigerant vapor that has been sprayed and evaporated from the sprayer 4A to the cold / hot water pipe 28 in the evaporator 4 is absorbed by the absorber. An eliminator 37 </ b> B that flows into 5 is provided.
Below the absorber 5, a rare liquid reservoir 5 </ b> B is formed in which the refrigerant vapor from the evaporator 4 accumulates the rare liquid absorbed in the concentrated liquid sprayed from the sprayer 5 </ b> A. The dilute liquid reservoir 5B is connected to a branch pipe 30 that extends from the refrigerant reservoir 4B and is provided with an on-off valve 33, and the dilute liquid pipe 20. In the absorber 5, a cooling water pipe 26 through which cooling water flows is arranged as a heat transfer pipe. The cooling water pipe 26 is disposed so as to pass through the inside of the condenser 3 through the inside of the absorber 5. The cooling water pipe 26 is provided with a cooling water pump 13, and the cold / hot water pipe 28 is provided with a cold / hot water pump 14 that is controlled to be variable in frequency by an inverter (not shown).

  The absorption refrigerator 100 has a cold / hot water inlet temperature sensor 51 that is provided on the evaporator 4 inlet side of the cold / hot water pipe 28 to detect the cold / hot water inlet temperature, and a cold / hot water pipe 28 that is provided on the evaporator 4 outlet side of the cold / hot water pipe 28. A cold water outlet temperature sensor 52 that detects the water outlet temperature, a cooling water inlet temperature sensor 53 that is provided on the inlet side of the absorber 5 of the cooling water pipe 26 to detect the cooling water inlet temperature, and a high temperature regenerator 1 are provided. A high temperature regenerator temperature sensor 54 that detects the high temperature regenerator temperature Th and a cold / hot water flow meter 55 that is provided in the cold / hot water pipe 28 and detects the cold / hot water flow rate f are provided.

  The absorption refrigerator 100 is provided with a control device 60 that controls the absorption refrigerator 100. The control device 60 includes a timing unit (not shown), an operation signal from a centralized control device 70 (see FIG. 2) to be described later for operating the absorption chiller 100, and a high-temperature regenerator detected by the liquid level detector 15. 1, the temperature of the absorbing liquid at 1, the temperature of the cold / hot water detected by the temperature sensors 51 to 54, the temperature of the high-temperature regenerator 1, the flow of cold / hot water detected by the cold / hot water flow meter 55, etc. . Then, the control device 60 performs ignition control of the igniter 9, opening / closing and opening control of the fuel control valve 10, control of the pumps 11 to 13, inverter control of the inverter of the cold / hot water pump 14 based on the acquired value. Run.

The absorption refrigerator 100 is controlled by the control device 60 so that the operation mode is switched between a cooling operation in which cold water is extracted from the cold / hot water pipe 28 and a heating operation in which hot water is extracted from the cold / hot water pipe 28.
During the cooling operation, the absorption-type refrigerator 100 is charged so that the temperature at the outlet side of the evaporator 4 of brine (for example, cold water) circulated and supplied to the heat load 300 through the cold / hot water pipe 28 becomes a predetermined set temperature, for example, 7 ° C. The amount of heat generated is controlled by the control device 60. Specifically, the control device 60 starts the pumps 11 to 14, burns fuel with the burner 8, and controls the burner 8 so that the brine temperature detected by the cold / hot water outlet temperature sensor 52 becomes a predetermined 7 ° C. Control firepower. In the cooling operation, the on-off valves 31 to 33 are closed.

  In this case, the absorbing liquid in the high-temperature regenerator 1 is heated by the burner 8 and concentrated to separate into an intermediate liquid and refrigerant vapor. The intermediate liquid flows through the absorption liquid tubes 22 and 22 </ b> A, passes through the high-temperature heat exchanger 6, is cooled by the dilute liquid flowing out from the absorber 5, and then enters the low-temperature regenerator 2. The refrigerant vapor generated in the high-temperature regenerator 1 flows through the refrigerant vapor pipes 21 and 21A, passes through the low-temperature regenerator 2, heats the intermediate liquid supplied to the low-temperature regenerator 2, condenses, and forms a liquid refrigerant. And enters the condenser 3. The intermediate liquid of the low temperature regenerator 2 heated by the refrigerant vapor from the high temperature regenerator 1 is concentrated and separated into concentrated liquid and refrigerant vapor. This refrigerant vapor enters the condenser 3 through the eliminator 36.

  The refrigerant vapor that has entered the condenser 3 from the low-temperature regenerator 2 is cooled by the cooling water flowing through the cooling water pipe 26 and becomes liquid refrigerant. The liquid refrigerant and the liquid refrigerant from the high-temperature regenerator 1 flow through the refrigerant pipe 25 and enter the evaporator 4, and accumulate in the refrigerant pool 4 </ b> B while partially evaporating. The liquid refrigerant accumulated in the refrigerant pool 4B is supplied to the spreader 4A in the evaporator 4 through the refrigerant pipe 27 by the refrigerant pump 12, and is spread from the spreader 4A to the surface of the cold / hot water pipe 28. At this time, the refrigerant takes heat of the hot water flowing through the cold / hot water pipe 28 by the heat of vaporization, and the hot water is cooled to become cold water. The cold water is supplied to the heat load 300 and a cooling operation such as cooling is performed. The refrigerant vapor evaporated in the evaporator 4 enters the absorber 5 through the eliminator 37B.

On the other hand, after the concentrated liquid concentrated in the low-temperature regenerator 2 is cooled by the diluted liquid flowing out of the absorber 5 by the absorption liquid pump 11 through the absorption liquid pipe 23 and passing through the low-temperature heat exchanger 7. , Supplied to the spreader 5A in the absorber 5, and sprayed from the spreader 5A to the surface of the cooling water pipe 26. In the absorber 5, the refrigerant vapor generated in the evaporator 4 is absorbed by the concentrated liquid and becomes a diluted liquid having a reduced concentration, and is stored in the diluted liquid pool 5B. The heat generated when the refrigerant vapor is absorbed by the concentrated liquid is cooled by the cooling water flowing through the cooling water pipe 26.
The dilute liquid accumulated in the dilute liquid reservoir 5 </ b> B of the absorber 5 is discharged from the dilute liquid pipe 20 by the absorption liquid pump 11. The diluted liquid flows through the diluted liquid pipe 20 and passes through the low-temperature heat exchanger 7 and is heated by the concentrated liquid flowing through the absorbing liquid pipe 23 and then passes through the high-temperature heat exchanger 6 and passes through the first absorbing liquid. The high temperature regenerator 1 is heated by the intermediate liquid flowing through the pipe 22A.

  During heating operation, the evaporator 4 outlet side temperature of brine (for example, hot water) circulated and supplied to the heat load 300 through the cold / hot water pipe 28 is charged into the absorption refrigeration machine 100A so as to be a predetermined set temperature, for example, 55 ° C. The amount of heat generated is controlled by the control device 60. Specifically, the control device 60 activates only the pumps 11, 13, and 14, burns fuel with the burner 8, and the brine temperature measured by the cold / hot water outlet temperature sensor 52 becomes a predetermined 55 ° C. The heating power of the burner 8 is controlled. During the heating operation, the on-off valves 31 and 32 are opened and the on-off valve 33 is closed.

In this case, the absorbing liquid in the high-temperature regenerator 1 is heated by the burner 8 and concentrated to separate into an intermediate liquid and refrigerant vapor. The intermediate liquid flows through the absorption liquid pipes 22 and 22B, enters the absorber 5 and accumulates in the dilute liquid pool 5B, and the refrigerant vapor flows through the refrigerant vapor pipe 21 and is mainly a second refrigerant having a small channel resistance. The gas enters the absorber 5 through the steam pipe 21B. The refrigerant vapor entering the absorber 5 enters the evaporator 4 through the eliminator 37B, is cooled by cold water flowing through the cold / hot water pipe 28, becomes liquid refrigerant, and accumulates in the refrigerant pool 4B. At this time, the cold water flowing through the cold / hot water pipe 28 is heated by the refrigerant vapor entering the evaporator 4 to become hot water. This hot water is supplied to the heat load 300 and a heating operation such as heating is performed. The refrigerant accumulated in the refrigerant reservoir 4B flows through the refrigerant pipe 27 and the branch pipe 30, enters the absorber 5, and accumulates in the rare liquid reservoir 5B. In the dilute liquid reservoir 5B, the refrigerant is absorbed by the intermediate liquid to become a dilute liquid having a reduced concentration, and this dilute liquid is circulated through the dilute liquid pipe 20 by the absorbing liquid pump 11 and supplied to the high temperature regenerator 1.
The absorption refrigerator 100 according to the present embodiment is configured such that the refrigerant condensed in the evaporator 4 flows through the refrigerant pipe 27 and the branch pipe 30 and enters the absorber 5. The refrigerant that is closed and condensed in the evaporator 4 and accumulated in the refrigerant reservoir 4B can overflow from the refrigerant reservoir 4B and enter the absorber 5.

  In addition, the control device 60 controls the frequency of the cold / hot water pump 14 so that the cold / hot water inlet temperature is constant, thereby suppressing the operation capacity of the cold / hot water pump 14 to reduce energy consumption. I do.

FIG. 2 is a configuration diagram schematically showing an absorption system 200 including a plurality of the absorption chillers 100.
The absorption system 200 is, for example, an absorption system including a plurality of (for example, five) absorption refrigerators 100 and a centralized control device 70, and is configured to be connected by, for example, a communication wiring 71 using a transition wiring. ing. Here, the absorption refrigeration machine 100 is distinguished from the absorption refrigeration machines 100A to 100E by reference numerals, and the components provided in the absorption refrigeration machine 100 also correspond to the absorption refrigeration machines 100A to 100E. The symbols A to E are attached and distinguished from each other.
In the present embodiment, the communication wiring 71 that connects the central control device 70 and each absorption chiller 100A to 100E is a crossover wiring. However, the present invention is not limited to this, and each absorption chiller 100A from the central control device 70 is used. The communication wiring 71 may be individually connected to ˜100E.

In the absorption system 200, the cold / hot water supplied from the cold / hot water pipes 28 </ b> A to 28 </ b> E of the absorption refrigerators 100 </ b> A to 100 </ b> E is supplied to the heat load 300 through the water supply pipe 301.
As described above, the absorption refrigerators 100A to 100E include the cold / hot water inlet temperature sensors 51A to 51E, the cold / hot water outlet temperature sensors 52A to 52E, the cold / hot water flow meters 55A to 55E, and the high temperature regenerators 1A to 1E. And high temperature regenerator temperature sensors 54A to 54E for detecting the temperatures of the high temperature regenerators 1A to 1E, burners 8A to 8E, and absorption refrigerators 100A to 100E including combustion control of the burners 8A to 8E. Control devices 60A to 60E that perform operation control and communication with the centralized control device 70 are provided, and from each absorption chiller 100A to 100E, the model, rated capacity, cold / hot water temperature, and high temperature regenerator temperature are provided. Data such as the flow rate of cold / hot water is transmitted to the central control device 70 through the communication wiring 71.

  In the present embodiment, the absorption refrigerator 100A is referred to as No. 1 (base machine), the absorption refrigerator 100B is referred to as No. 2, the absorption refrigerator 100C is referred to as No. 3, and the absorption refrigerator 100D. Is referred to as No. 4, absorption refrigeration machine 100E is referred to as No. 5, and the priorities in which these absorption refrigeration machines 100A to 100E are operated are absorption refrigeration machine 100A, absorption refrigeration machine 100B, absorption refrigeration machine 100C. The absorption refrigeration machine 100D and the absorption refrigeration machine 100E will be described in this order, but this priority is determined in the order of the refrigeration capacity of the absorption refrigeration machines 100A to 100E regardless of the unit number. Alternatively, for example, an absorption refrigerator that can recover exhaust heat from an external heat source may be given priority.

The centralized control device 70 performs collective management of the received data, and instructs the absorption chillers 100A to 100E to stop operation or to operate.
And when operation is instruct | indicated by operation of the operation switch (not shown) provided in the panel surface of the centralized control apparatus 70, the centralized control apparatus 70 will respond according to the load (absorption type system load) of the absorption system 200. Then, unit control for controlling the number of operating absorption chillers 100A to 100E is started.

When the absorption system 200 is activated, even if there is a load, the capacity is not obtained, and an accurate load cannot be determined. Therefore, the centralized control device 70 has a predetermined time to (for example, 30 minutes) from the activation start of the absorption system 200. stand by. When the predetermined time to elapses, the central control device 70 calculates the load of the absorption chiller 100 during operation (absorption chiller load) as the equipment load ratio Lchi. The equipment load ratio Lchi of each absorption chiller 100 is the cold / hot water inlet temperature detected by the cold / hot water inlet temperature sensor 51 of the absorption refrigerator 100, the cold / hot water outlet temperature detected by the cold / hot water outlet temperature sensor 52, and the cold / hot water. Using the cold / hot water flow rate f detected by the flow meter 55, the flow rate is obtained by the following calculation formula (1).
Equipment load ratio Lchi = ΔT (temperature difference between cold / hot water inlet temperature and cold / hot water outlet temperature) × cold / hot water flow rate f (1)

The central control device 70 calculates the load of the absorption system 200 as the load ratio Lch by taking into account the capacity setting of the absorption refrigerator 100 from the equipment load ratio Lchi of the operating absorption refrigerator 100.
For example, three absorption chillers 100A to 100C each having a capacity setting of 40 refrigeration tons are in operation, and the equipment load ratio Lchi of the absorption chillers 100A to 100C is 80%, 60%, and 40%. Then, the load ratio Lch of the absorption system 200 is 40 / (40 + 40 + 40) × 0.8 + 40 / (40 + 40 + 40) × 0.6 + 40 / (40 + 40 + 40) × 0.6 = 0.6 (60%).
On the other hand, three absorption refrigeration machines 100A to 100C having capacity settings of 80 refrigeration tons, 60 refrigeration tons, and 40 refrigeration tons are operating, and the equipment load ratio Lchi of the absorption refrigeration machines 100A to 100C is 80. %, 60%, and 40%, the load ratio Lch of the absorption system 200 is 80 / (80 + 60 + 40) × 0.8 + 60 / (80 + 60 + 40) × 0.6 + 40 / (80 + 60 + 40) × 0.4 = 0.644 ( 64.4%).
The centralized control device 70 controls the number of operating units according to the load ratio Lch calculated as described above based on the operating number control table TB shown in FIG. The operating number control table TB is stored in a storage unit (not shown) provided in the central control device 70.

As shown in Condition 1, when the load ratio Lch is equal to or less than the predetermined load α × capacity ratio E%, the central control device 70 decreases the number of operating absorption chillers 100 by one from the lowest priority order. Then, it waits for a predetermined time t1 (for example, 30 minutes). Here, the load α is a value (for example, 90%) indicating the refrigeration capacity at 100% load, and the capacity ratio E is a value (for example, 0.95) indicating the capacity ratio relative to the refrigeration capacity at the 100% load. is there. In this way, by adding the capacity ratio E, the number of operating units can be appropriately controlled even when the capacity of the absorption chiller 100 is reduced due to deterioration over time.
Further, as shown in Condition 2, when the load ratio Lch is equal to or less than a predetermined load β% (for example, 45%), the central control device 70 stops the absorption chiller 100 other than the base machine (No. 1 machine). .

  On the other hand, as shown in condition 3, when the load ratio Lch is greater than or equal to a predetermined load α% (for example, 90%) and continues for a predetermined time t2 (for example, 5 minutes), or the high temperature regenerator temperature Th is the predetermined temperature Th1. When the predetermined time t3 (for example, 5 minutes) is continued at (for example, 150 ° C.) or more, the centralized control device 70 increases the number of operating absorption chillers 100 by one from the highest priority, and then Wait for a predetermined time t4 (for example, 5 minutes). Here, the high temperature regenerator temperature Th is an average value calculated by taking into account the capacity setting of the absorption refrigerating machine 100 from the high temperature regenerator temperature received from the operating absorption refrigerating machine 100.

  As shown in condition 4, regardless of condition 3, the chilled / hot water outlet temperature Tout is equal to or higher than a predetermined temperature Tout1 (eg, 9 ° C.) during cooling, and the chilled / hot water outlet temperature Tout is set to a predetermined temperature Tout2 (eg, 53 ° C.) during heating. ) When a predetermined time t5 (for example, 10 minutes) is continued in the following, the central control device 70 increases the number of operating absorption refrigeration machines 100 by one from the highest priority, and then the predetermined time t5 ( (For example, 30 minutes) Wait. Here, the cold / hot water outlet temperature Tout is an average value calculated from the cold / hot water outlet temperature received from the operating absorption refrigerator 100 in consideration of the capacity setting of the absorption refrigerator 100.

  Note that the predetermined loads α and β, the capacity ratio E, the predetermined times t1 to t5, and the predetermined temperatures Th1, Tout1, and Tout2 can be changed by operation switches provided on the panel surface of the central control device 70. In addition, the values of the predetermined loads α and β, the capacity ratio E, the predetermined times t1 to t5, and the predetermined temperature Th1 may be changed between the cooling operation and the heating operation. Further, the predetermined temperatures Tout1 and Tout2 may be set by setting a temperature difference from a set temperature of the cold / hot water outlet temperature (7 ° C. during cooling, 55 ° C. during heating). The predetermined loads α and β, the capacity ratio E, the predetermined times t1 to t5, and the predetermined temperatures Th1, Tout1, and Tout2 (or the set temperature of the cold / hot water outlet temperature) are stored in the storage unit provided in the central control device 70.

FIG. 4 is an explanatory diagram showing an example of the number control of the absorption system 200.
In the example of FIG. 4, all the absorption chillers 100 are first operated (five units). When the load ratio Lch becomes equal to or less than the predetermined load α × capacity ratio E% (point P1), the central control device 70 stops the absorption chiller 100 having the lowest priority (No. 5 machine (absorption chiller 100E)). . When the load ratio Lch is equal to or less than the predetermined load α × capacity ratio E% even after the predetermined time t1 has elapsed (point P2), the central control device 70 has the absorption refrigeration machine 100 (No. 4) having the next lowest priority. (Absorption refrigerator 100D)) is stopped. When the load ratio Lch is equal to or less than the predetermined load α × capacity ratio E% even after the predetermined time t1 has elapsed (point P3), the central control device 70 has the absorption refrigeration machine 100 (No. 3) having the next lowest priority. (Absorption refrigerator 100C)) is stopped.
When the load ratio Lch becomes equal to or less than the predetermined load β% (point P4), the centralized control device 70 stops the units other than the base unit of the absorption chiller 100 (No. 1 machine (absorption chiller 100A)).

  When the load ratio Lch is equal to or greater than the predetermined load α% and continues for the predetermined time t2 (point P5), the centralized control device 70 has the absorption chiller 100 (No. 2) having the highest priority among the absorption chillers 100 being stopped. (Absorption refrigerator 100B)) is operated. When the load ratio Lch is equal to or higher than the predetermined load α% and continues for the predetermined time t2 or more even after the predetermined time t4 has elapsed (point P6), the central control device 70 has the absorption refrigeration machine 100 (No. 3) having the next highest priority. (Absorption type refrigerator 100C)) is operated.

  When the load ratio Lch becomes equal to or less than the predetermined load α × capacity ratio E% (point P7), the central control device 70 has the absorption refrigerator 100 (No. 3 (lowest priority) among the absorption refrigerators 100 in operation). Absorption refrigerator 100C)) is stopped. When the load ratio Lch is equal to or less than the predetermined load α × capacity ratio E% even after the predetermined time t1 has elapsed (point P8), the central control device 70 has the absorption refrigeration machine 100 (No. 2) having the next lowest priority. (Absorption refrigerator 100B)) is stopped.

FIG. 5 is an explanatory diagram showing another example of the number control of the absorption system 200. In FIG. 5, the control of points P1 to P4 is the same as the control shown in FIG.
When the high-temperature regenerator temperature Th is equal to or higher than the predetermined temperature Th1 and continues for the predetermined time t3 (point P9), the central control device 70 takes the absorption refrigerator 100 (2) having the highest priority among the absorption refrigerators 100 being stopped. Unit (absorption refrigerator 100B)) is operated. When the high temperature regenerator temperature Th is equal to or higher than the predetermined temperature Th1 and continues for the predetermined time t3 even after the predetermined time t4 has elapsed (point P10), the central control device 70 determines that the absorption refrigerator 100 (3 Unit No. (absorption refrigerator 100C)) is operated.

  When the load ratio Lch becomes equal to or less than the predetermined load α × capacity ratio E% (point P11), the central control device 70 has the absorption chiller 100 (No. 3 (lowest priority) among the absorption chillers 100 in operation). Absorption refrigerator 100C)) is stopped. When the load ratio Lch is equal to or less than the predetermined load α × capacity ratio E% even after the predetermined time t1 has elapsed (point P12), the central control device 70 has the absorption refrigeration machine 100 (No. 2) having the next lowest priority. (Absorption refrigerator 100B)) is stopped.

  As described above, according to the present embodiment, the centralized control device 70 determines the temperature of the cold / hot water outlet temperature and the temperature of the cold / hot water outlet of the evaporator 4 included in the absorption refrigerator 100 operating the absorption refrigerator load. It calculates from the difference and the flow rate of the cold / hot water, calculates the absorption system load from this absorption refrigerator load, and controls the number of operating absorption refrigerators 100 according to this absorption system load. . With this configuration, each absorption chiller 100 can control the number of units even when cold / hot water variable flow control is performed in which the cold / hot water inlet temperature is kept constant, thereby further saving energy. Can be realized.

  In addition, according to the present embodiment, the centralized control device 70 controls the number of operating absorption chillers 100 according to the ratio of the refrigeration capacity at 100% load. Even if the capacity of the system drops, the number of operating units can be controlled appropriately.

  Further, according to the present embodiment, the central control device 70 is configured to increase the number of operating absorption chillers 100 when the absorption system load becomes equal to or higher than the predetermined load for a predetermined time. With this configuration, it is possible to prevent frequent switching of operation / stop of the absorption chiller 100, thereby realizing energy saving.

  In addition, according to the present embodiment, each absorption refrigerator 100 includes the high-temperature regenerator 1 and the low-temperature regenerator 2 as regenerators, and the central control device 70 is configured such that the absorption system load exceeds a predetermined load for a predetermined time. In such a case, or when the high-temperature regenerator temperature of the absorption chiller 100 reaches a predetermined temperature for a predetermined time or more, the number of operating absorption chillers 100 is increased. With this configuration, it is possible to prevent the absorption refrigerator 100 from being operated in a state where the high-temperature regenerator temperature is high while increasing the number of operating absorption refrigerators 100 according to the absorption system load. The life of the machine 100 can be extended.

However, the above embodiment is an aspect of the present invention, and it is needless to say that the embodiment can be appropriately changed without departing from the gist of the present invention.
For example, in the above embodiment, both the load ratio and the high temperature regenerator temperature are determined in Condition 3, and the number control is performed when either condition is satisfied. However, only the load ratio may be determined. Only the high temperature regenerator temperature may be determined. Furthermore, when determining the load ratio or the high temperature regenerator temperature, the setting for determining only the load ratio or only the high temperature regenerator temperature can be switched by the operation switch provided on the panel surface of the central control device. Also good.

Moreover, in the said embodiment, although the flow rate of cold / hot water was detected with the cold / hot water flowmeter, it is not limited to this, For example, you may measure with a pressure gauge. Further, the flow rate of the cold / hot water when the cold / hot water pump is operated at a predetermined rated frequency (for example, 60 Hz) is defined as the rated flow rate, and the ratio between the rated flow rate and the operation frequency output from the inverter to the cold / hot water pump. Alternatively, the flow rate of cold / hot water may be calculated.
Moreover, in the said embodiment, although the priority order of the absorption refrigerator was fixed, it is good also as replacement | exchange possible with the operation switch provided in the panel surface of the centralized control apparatus.

1 High temperature regenerator (regenerator)
2 Low temperature regenerator (regenerator)
DESCRIPTION OF SYMBOLS 3 Condenser 4 Evaporator 5 Absorber 51 Chilled / hot water inlet temperature sensor 52 Chilled / hot water outlet temperature sensor 54 High temperature regenerator temperature sensor 55 Chilled / hot water flow meter 70 Centralized control device 100, 100A-100E Absorption type refrigerator 200 Absorption type system

Claims (5)

In an absorption system including a plurality of absorption chillers including a regenerator, a condenser, an evaporator, and an absorber, and a centralized control device that centrally controls the plurality of absorption chillers,
Each absorption refrigerator is
A cold / hot water pump that is controlled to be variable in frequency and controls the flow rate of the cold / hot water in the evaporator provided in the absorption refrigerator,
A controller for controlling the frequency of the cold / hot water pump so that the cold / hot water inlet temperature of the cold / hot water is constant,
The central control device includes a difference between a cold / hot water outlet temperature of an evaporator and a cold / hot water outlet temperature of an evaporator included in the absorption refrigerator that is operating the absorption refrigerator load of the absorption refrigerator that is operating, and the cold temperature calculated from the flow rate of water, to calculate the absorption system load from the absorption chiller load, the number of operating the absorption refrigerating machine is increased or decreased in response to the absorption system load, corresponding to the absorption system load Regardless of the increase or decrease in the number of operating absorption chillers, if the cold / hot water outlet temperature of the absorption chiller during operation continues for a predetermined time at a predetermined temperature or higher during cooling, the absorption chiller during operation during heating When the temperature of the hot / cold water outlet is below a predetermined temperature and continues for a predetermined time, the absorption system is characterized in that the number of operating absorption refrigerators is increased.   The absorption system according to claim 1, wherein the central control device controls the number of operating absorption chillers according to the ratio of the refrigeration capacity at 100% load.   The absorption system according to claim 1 or 2, wherein the central control device increases the number of operating absorption chillers when the absorption system load exceeds a predetermined load for a predetermined time. . Each absorption refrigerator includes a high temperature regenerator and a low temperature regenerator as the regenerator,
The centralized control device increases the number of operating absorption chillers when the high-temperature regenerator temperature of the absorption chiller reaches a predetermined temperature for a predetermined time or longer. Absorption system as described. Each absorption refrigerator has a high temperature regenerator and a low temperature regenerator as regenerators,
When the absorption system load becomes a predetermined load or more for a predetermined time, or when the high-temperature regenerator temperature of the absorption chiller becomes a predetermined temperature for a predetermined time or more, the centralized control device The absorption system according to claim 1 or 2, wherein the number of operating refrigerators is increased.

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