JP2003106703A - Absorption system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorption system including a plurality of triple utility type absorption refrigerating machines connected by cross-cover communication wiring and a central controlling unit, which decreases the corrosion rate of absorbent and improves the fuel efficiency. SOLUTION: Data of partial load characteristic is saved in a central controlling unit and data of the rated capabilities of absorption refrigerating machines that are connected to each other are central-controlled. Accordingly, it becomes possible to made each of the absorption refrigerating machines perform the partial load operation mainly. Consequently, the operation is able to keep low the regeneration temperature of lean solution, reduce the corrosion rate and improve the fuel efficiency. In terms of improving the fuel efficiency, it is not particularly limited to a triple utility type absorption refrigerating machine but is effective to a dual utility type absorption refrigerating machine, as operation control means for an absorption system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to operation control of a plurality of absorption refrigerators connected in parallel to a refrigerant pipe, and particularly to operation control of a plurality of triple effect absorption refrigerators.

[0002]

2. Description of the Related Art Up to now, when a plurality of absorption chillers and a centralized control device are installed and the operation control of the absorption chiller is performed from the centralized control device, first, The temperature difference between the preset cold water temperature and the preset temperature determines the number of operating vehicles at the start of operation, and starts the operation. Due to the temperature difference, the absorption chiller that started the operation increases or decreases its input amount and operates by increasing or decreasing the capacity from the minimum capacity of the absorption chiller to the rated capacity. If there is a difference in temperature, the centralized control device increases or decreases the number of operating units to perform operation control corresponding to the air conditioning load. That is, when a plurality of absorption refrigerating machines operate in response to an air conditioning load, some of the plurality of absorption refrigerating machines perform a rated operation, one performs a partial load operation, and the remaining The absorption chiller of No. 3 was in a stopped operating state.

Further, in the double-effect absorption refrigerator, the temperature of the absorbing liquid in the high temperature regenerator is 160 when operating at the rated capacity.
Since the regeneration pressure is about atmospheric pressure at about ℃, it is possible to manufacture up to several thousand RT, while the triple-effect absorption chiller is regenerated at high temperature when operating at rated capacity. The temperature of the absorbing liquid in the vessel rises to nearly 200 ° C, and its pressure greatly exceeds atmospheric pressure.
Since it is possible to manufacture only up to about 00RT, it is inevitable to install a plurality of units for a large scale air conditioning load.

[0004]

In the case of a triple-effect absorption refrigerator, the temperature of the absorbing liquid in the high temperature regenerator is 2 during rated operation.
The temperature may reach close to 00 ° C, and the regeneration pressure may greatly exceed the atmospheric pressure. Therefore, in the conventional operation method of the absorption refrigerating machine, the corrosion rate increases due to the temperature increase of the regeneration temperature,
Since there is concern about the influence of the pressure during operation, it has been desired to develop an operation method in which the regeneration temperature is lowered and the corrosion rate is suppressed.

Therefore, an object of the present invention is to lower the regeneration temperature of the absorbing liquid and suppress the corrosion rate by making the operation of the plurality of absorption refrigerators for the air conditioning load mainly the partial load operation. An object of the present invention is to provide an absorption type system capable of operation control with an improved fuel consumption rate by the partial load operation.

[0006]

According to a first aspect of the present invention, there is provided an absorption type system comprising a plurality of absorption type refrigerating machines, wherein these absorption type refrigerating machines are controlled by a central control device.
The control unit of each absorption refrigerator and the centralized control device are connected by communication wiring by a crossover, and the centralized controller is
It is characterized in that the operation of the absorption chiller per unit is mainly controlled to the partial load operation.

According to a second aspect of the present invention, in an absorption type system including a plurality of absorption type refrigerating machines and controlling these absorption type refrigerating machines by a centralized control device, a control unit of each absorption type refrigerating machine, When the centralized control device is connected to the centralized control device by communication wiring by a crossover and the centralized control device increases the number of operating absorption type refrigerators according to the air conditioning load, the absorption type refrigerator in operation has its rated capacity. It has a function of starting the operation of the absorption refrigerating machine which is stopped before reaching.

According to a third aspect of the present invention, in the first or second aspect, the absorption refrigerating machine is a triple effect absorption refrigerating machine.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an embodiment of the present invention.
~ It demonstrates with reference to FIG.

The absorption refrigerator uses the refrigeration principle that water that evaporates at 100 ° C. in the atmosphere evaporates even at a low temperature (about 5 ° C.) in a high vacuum state to perform cooling operation. The absorption liquid circulating in the absorption refrigerating machine is sprayed and evaporated on a cold water pipe in which a water refrigerant circulating to the indoor side flows to absorb heat, thereby performing a cooling operation.

With respect to the structure of the absorption refrigerator, referring to FIG. 1, in order to regenerate the capacity of the absorbing liquid, it is heated by the burner 15 to vaporize the water content of the absorbing liquid to increase the liquid concentration and increase the water absorption. The high temperature regenerator 1 that works to raise the temperature, the liquid absorption liquid concentrated in the high temperature regenerator 1 is heated again by the steam generated and separated in the high temperature regenerator 1, and the medium temperature regenerator 2 that further increases the liquid concentration and the absorber 6 From the low temperature regenerator 3 which is provided in the middle of the absorption liquid pipe sent from the medium to the high temperature regenerator 1 and preheats the absorption liquid by the steam generated in the medium temperature regenerator 2, and the refrigerant vapor is cooled and liquefied, so that the inside is cooled. A condenser 4 provided with a condenser pipe 14 for passing water and a cold water pipe 13 for passing water, which is a water refrigerant for carrying heat to the load side, are provided with a condenser 4 and cooled by the condenser 4. The sprayed water is sprinkled on the cold water pipes 13 through which the water refrigerant passes, and evaporated to remove the water from the water refrigerant. For thermal transfer made to perform an endothermic evaporator 5 to generate cold water as the output of the absorption chiller
And an absorber 6 which mainly dissolves the water vapor re-evaporated in the evaporator 5 into the absorption liquid concentrated in the high temperature regenerator 1 and the medium temperature regenerator 2, and in addition to this, in the absorption refrigerator, In order to increase efficiency, the low-temperature heat exchanger 7 that performs auxiliary heating of the absorption liquid sent from the absorber 6 to the low-temperature regenerator 3 and the absorption liquid sent from the low-temperature regenerator 3 to the high-temperature regenerator 1 and the intermediate-temperature regenerator 2 A medium temperature heat exchanger 8 for assisting reheating, a high temperature heat exchanger 9, and an absorption liquid pump 1 for circulating this absorption liquid.
0 and 11, the refrigerant pump 12, operation signals from the central control panel for operating the absorption refrigerator, and temperature data from the temperature sensors that detect the temperature of each part including the high temperature regenerator temperature sensor 16. Of the burner 15 of the high temperature regenerator 1 and the control panel 20 that outputs the signals for adjusting the opening of each pump and each control valve.

The operation of the absorption refrigerating machine main body will be briefly described. First, referring to the timing chart shown in FIG. 2, first, an operation instruction signal from the central operation panel or an operation of the control panel 20 is performed. When the operation is started by the switch, first, the operation instruction of the chilled water pump is output to start the circulation of the chilled water that is the water refrigerant, and as a reply that the chilled water pump has normally operated, the chilled water pump interlocks. The signal is coming. Then, an operation instruction of the cooling water pump is output to start the circulation of the cooling water, and an interlock signal is transmitted from the cooling water pump as confirmation that the cooling water pump has normally operated. When the absorption refrigerating machine receives these two interlock signals, the burner 15 in the high temperature regenerator 1 is ignited to start combustion, and at the same time, the absorbent pump 1
0 and 11 and the refrigerant pump 12 were operated to start the circulation of the absorbing liquid to bring them into an operating state, and then an operation instruction was output to the cooling tower blower for operation, and this cooling tower blower operated normally. As confirmation of this, an interlock signal is transmitted from the cooling leg tower blower, and this signal is received by the absorption refrigerator. During the operation of the absorption refrigerator, the combustion amount of the burner 15 and the absorption liquid circulation amount in the refrigerant pump 12 are caused by the temperature difference between the preset cold water temperature and the cold water temperature detected by the cold water temperature sensor 17. Is adjusted, and the liquid level sensor 18 that detects the amount of the absorbing liquid stored in the evaporator 5 operates the absorbing liquid pump 10.
According to the cooling water temperature detected by the cooling water temperature sensor 19,
The cooling tower blower is operated. Then, when the stop signal is input, first, the combustion amount of the burner 15 is throttled and then stopped, then the refrigerant pumps 10 and 11 and the cooling water pump are stopped, and finally, the cold water pump and the absorbing liquid. The pump 12 is stopped and the operation ends.

Next, C in the partial load operation of the absorption refrigerator
The improvement of OP will be described with reference to FIG.
In the case of a double-effect absorption chiller, FIG. 4 is a diagram showing the relationship between the operating capacity of the absorption chiller with respect to the cooling load and the fuel consumption rate, and expressing the respective values as percentages for comparison.

That is, the operating capacity of the absorption refrigerator is 100.
In the case of% (rated operation), the fuel consumption rate is shown as 100%, which is not shown, but when compared in terms of heat quantity units, the COP value is about 1.3. In 3, the driving ability on the dashed-dotted line,
If the fuel consumption rate changes, the output is 1 for the input 1, so the COP is about 1.3 as in the above case.

The solid line represents the actual operating capacity and fuel consumption rate of the absorption chiller. As can be seen from FIG. 3, the maximum operating capacity is 100%, and the fuel consumption rate at this time is 100%. 1
The minimum operating capacity is about 20%.
The fuel consumption rate is about 20%.

Here, from about 20% to about 30% of the minimum operating capacity is shown by a broken line, which is slightly different depending on the model and capacity, but is installed in the absorption refrigerator. In the range below this combustion burner combustion control range, the combustion burner performs on / off combustion control in the range indicated by this broken line, and in the range indicated by the solid line above this range. Combustion control is performed depending on the intensity of combustion.

However, for the partial load operation between the minimum operating capacity and the maximum operating capacity, the above COP = 1.3.
It is a curve that draws a gentle arc below the dashed line. This means that the fuel consumption rate is lower than the driving ability, and in other words, the COP is 1.3 or more.
That is, if the partial load operation is mainly performed by the operation of the absorption chiller, the fuel consumption can be reduced, and the air-conditioning operation with reduced running cost is possible. In addition, by reducing the fuel consumption, it is possible to carry out the air conditioning operation in consideration of the environment.

Therefore, the operating method mainly for the partial load operation of the absorption chiller according to the present invention will be described with reference to FIGS. 4 to 6. FIG. 4 shows, for example, three absorption chillers 21A to 21C.
An absorption type system equipped with a table and a central control device 27,
It is configured to be connected by a communication wiring 28 formed by a crossover wiring.

On one of the absorption type refrigerators 21A to 21C,
At least the cold water temperature sensors 22A to 22C, the high temperature regenerators 23A to 23C, the high temperature regenerator temperature sensors 24A to 24C for detecting the temperature of the high temperature regenerator, and the burner 25A.
.About.25C and operation controls of the absorption chillers 21A to 21C including combustion control of the burner, and control units 26A to 26C for communicating with the centralized control device 27, respectively. Data such as the model, rated capacity, cold water temperature, and high temperature regenerator temperature are transmitted from the machines 21A to 21C to the centralized control device 27 through the communication wiring 28.

The other central control unit 27 collectively manages the received data, and each of the absorption refrigerators 21A to 21A-2.
An instruction to stop the operation or an instruction to the driving ability is given to 1C. Further, the central control device 27 stores partial load characteristic data of the double-effect absorption refrigerator and the triple-effect absorption refrigerator in advance, and although not shown, this central control is performed. By operating the operation switch provided on the board surface of the device 27, the set temperature of the chilled water temperature taken out from the absorption chillers 21A to 21C and the partial load operation of the absorption chillers 21A to 21C connected by the communication wiring 28 are selected. The upper limit and are set.

When the operation is instructed by the operation signal from the central control panel or the operation of the operation switch provided on the panel of the centralized control device 27, the operation control is performed according to the flow charts shown in FIG. 5 and FIG. The unit number control is started.

First, in the centralized control device 27, the partial load characteristic data stored in the centralized control device 27, the upper limit value setting of the partial load operation by the operation of the operation switch, and the rated capacity of the absorption chillers 21A to 21C. With the data of
The upper limit operation capacity b (i) of each of the absorption chillers 21A to 21C during partial load operation is calculated (S1). Here, i is the machine number of the absorption refrigerator.

Next, the average value TiA of the cold water temperature data received from the absorption refrigerators 21A to 21C is calculated (S
2), the temperature difference T between this average value TiA and the set temperature Ts
Dif is calculated (S3), and the air conditioning load A is calculated from this temperature difference TiA and the flow rate of cold water (S4).

Next, it is judged whether or not the absorption type system is in operation (S5). If it is in operation, it is confirmed whether or not there is a stop signal (S6). If there is a stop signal, stop processing is performed. Go (S7), return to step 2, and if there is no stop signal,
The number of units is controlled according to the increase or decrease of the air conditioning load (S20), and the process proceeds to step 19 described later.

In step 5 above, if the absorption type system is not in operation, it is confirmed whether or not there is an operation signal (S
8) If there is no operation signal, return to step 2. If there is an operation signal, the air conditioning load A calculated in step 4 is saved in the memory g (S9), and the operation instruction capacity e (1) is sent to Unit 1 (here). Then, the upper limit operating capacity b (1) at the time of partial load operation of the absorption chiller 21A) is set (S10), this operating instruction capacity e (i) is subtracted from the memory g, and the subtraction value C is obtained. Obtained (S11), it is determined whether or not the subtraction value C is greater than 0 (zero) (S12). If the subtraction value C is greater than 0 (zero), the subtraction value C is stored in the memory d. (S13), the value of the memory g is replaced with the value of the subtracted value C (S14), and the operation instruction capacity e (i) is set to the upper limit of the second unit (absorption refrigerator 21B) during partial load operation. Set the driving ability b (2) (S15), return to step 10, and perform the calculation again That is, the upper limit operating capacity of the partial load operation of each absorption chiller obtained in step 1 above is
By subtracting from the air conditioning load A in order from Unit 1, 1
The operation capacity corresponding to the air conditioning load A is distributed in order from the No. unit, and it is determined that the distribution of the operation capacity corresponding to the air conditioning load A is completed by the subtraction value C becoming 0 (zero) or a negative value. is doing.

In step 12, the subtraction value C is 0 (zero).
Alternatively, if it is determined to be a negative value, it is determined whether or not the subtraction value C is 0 (zero) (S16). If the subtraction value C is 0 (zero), the process proceeds to step 18, If the subtraction value C is a negative value, the value in the memory d which is the value before the last subtraction in step 11 is set to the driving instruction capability e.
Set to (i) (S17), this driving instruction ability e
(I) and the instruction to start the operation are given for each absorption refrigerator 21A-
21C to start driving (S18), step 4
The air conditioning load A calculated in step S1 is stored in the memory f (S1
9) Return to step 2 and repeat this flowchart.

In this embodiment, the distribution of the operating capacity from the air conditioning load A to the absorption chillers is explained in order from the first unit (absorption chiller 21A). Is for clarifying the explanation, and in actuality, it may be the distribution of the driving ability from Unit 2 or Unit 3 because of the rotation control of the driving and the control for leveling the driving time. It is not necessary to start from Unit 1 in order.

Next, regarding the number control in step 20,
This will be described with reference to FIG. 6. First, the previously calculated air conditioning load stored in the memory f and the air conditioning load A calculated this time are stored.
Is calculated (S30), it is determined whether this difference h is an increase (S31), and if it is not an increase, it is determined whether it is a decrease (S32). The sequence for controlling the number of units is completed and the process proceeds to step 19.

If it is determined that the air conditioning load difference h calculated in step 30 is greater than 0 (zero) and the air conditioning load has increased, the upper limit of the partial load operation of the absorption refrigerating machine currently in operation. It is judged whether or not there is one operating below the operating capacity of (S33), and if it exists, the absorption refrigerating machine operating below the upper limit operating capacity of the partial load operation is selected. Then (S34), the process proceeds to step 36,
If it does not exist, it is judged that all the operating absorption refrigerating machines are operating with the upper limit operating capacity of the partial load operation, and one of the stopping absorption refrigerating machines is selected ( S
35).

Next, it is judged whether or not the selected absorption refrigerating machine has an operating capacity margin corresponding to the air conditioning load difference h (S36). The operating capacity corresponding to the load difference h is increased by increasing the operating capacity of the selected absorption refrigerating machine (S37), and the process proceeds to step 19, and if there is no margin, the operating capacity of the selected absorption refrigerating machine is set. The operation capacity is increased to the upper limit operation capacity of the partial load operation, and at the same time, one of the stopped absorption chillers is instructed to perform the operation capacity of the shortage with respect to the difference h of the air conditioning load to start the operation (S38). Proceed to 19.

If the air-conditioning load difference h is a negative value in step 32, the absorption refrigerating machine currently in operation is operated below the upper limit operating capacity of the partial load operation. It is determined whether or not there is one that exists (S39), and if it exists, an absorption refrigerator that operates below the upper limit operating capacity of the partial load operation is selected (S40), and step 42 If it does not exist, one of the absorption refrigerators operating at the upper limit of the partial load operation is selected (S41), and the process proceeds to step 42.

Next, it is judged whether or not the selected absorption refrigerating machine is currently operated with an operating capacity corresponding to the air conditioning load difference h or more (S42), and the air conditioning load difference h or more is determined. If not, the selected absorption refrigerating machine is stopped and the operation capacity of any absorption refrigerating machine operating at the upper limit operation capacity of the partial load operation is reduced (S43). If it is determined that the absorption chiller has been operated at the difference h of the air conditioning load or more, the operating capacity of the selected absorption chiller is reduced (S4).
4) Go to step 19.

As described above, with respect to the air conditioning load, the upper limit of the operable range of the absorption refrigerator connected to the absorption system is set below the rated operation, and the operation is started within that range. Also, in the unit control, the absorption refrigerating machine in operation is operating at the rated operation or less, and the operation of the absorption refrigerating machine in stop is started to start the operation in the partial load operation. Let it be done.

[0034]

From the above description, by making the operation of a plurality of absorption refrigerating machines against the air conditioning load mainly the partial load operation, the regeneration temperature of the absorption liquid is lowered and the corrosion rate can be suppressed. Further, it becomes possible to improve the fuel consumption rate by the partial load operation.

Further, in terms of improving the fuel consumption rate by the partial load operation, the operation control means is effective not only in the triple effect type absorption refrigerator but also in the double effect type absorption refrigerator. .

[Brief description of drawings]

FIG. 1 is a schematic diagram of absorption liquid and control of an absorption refrigerator.

FIG. 2 is a timing chart showing a schematic operation of the absorption refrigerator.

FIG. 3 is a schematic diagram of an absorption type system in which a plurality of absorption type refrigerating machines and a centralized control device according to the present invention are connected by a communication path capable of communicating.

FIG. 4 is a schematic diagram showing the configuration of an absorption system according to the present invention.

FIG. 5 is a flowchart showing a schematic operation from start to stop of operation in the absorption system according to the present invention.

FIG. 6 is a flowchart showing a schematic operation of controlling the number of vehicles in the absorption system according to the present invention.

[Explanation of symbols]

1 High temperature regenerator 2 Medium temperature regenerator 3 low temperature regenerator 4 condenser 5 evaporator 6 absorber 7 Low temperature heat exchanger 8 Medium temperature heat exchanger 9 High temperature heat exchanger 10 Absorption liquid pump 11 Absorption liquid pump 12 Refrigerant pump 13 Cold water pipe 14 Condenser tube 15 burners 16 High temperature regenerator temperature sensor 17 Cold water temperature sensor 18 Liquid level sensor 19 Cooling water temperature sensor 20 control panel 21 Absorption refrigerator 22 Cold water temperature sensor 23 High temperature regenerator 24 High temperature regenerator temperature sensor 25 burners 26 Control unit 27 Centralized control device 28 Communication wiring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Haruki Nishimoto             1 Otsuki-cho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning             Within the corporation F term (reference) 3L093 BB11 BB16 BB22 CC07 DD08                       EE14 EE17 GG02

Claims (3)

[Claims] 1. An absorption type system comprising a plurality of absorption type refrigerating machines, wherein these absorption type refrigerating machines are controlled by a centralized control device. In the absorption type system, a control unit of each absorption type refrigeration machine and a centralized control device are connected. The absorption type system is characterized in that the centralized control device controls the operation of the absorption type refrigerating machine per unit mainly to the partial load operation while being connected by the communication wiring according to. 2. An absorption type system comprising a plurality of absorption type refrigerating machines, wherein these absorption type refrigerating machines are controlled by a centralized control device. In the absorption type system, a control unit of each absorption type refrigerating machine and a centralized control device are connected. When the central control unit increases the number of operating absorption chillers according to the air-conditioning load, the absorption chillers in operation are stopped before reaching their rated capacity. An absorption type system having a function of starting operation of an absorption type refrigerator. 3. The absorption system according to claim 1, wherein the absorption refrigerator is a triple-effect absorption refrigerator.