JP2018169075A - Absorption type refrigerating machine - Google Patents

Abstract

An absorption refrigerator capable of constantly monitoring COP and maintaining COP at a certain level or higher is provided.
SOLUTION: A high temperature regenerator 5, a low temperature regenerator 6, an evaporator 1, a condenser 7 and an absorber 2 are connected, and these are connected by piping to form a circulation path for an absorbing liquid and a refrigerant, respectively. Occasionally, the COP is calculated, the COP increase / decrease rate is calculated from the calculated COP and the assumed COP, and when it is determined that the average COP increase / decrease rate for one month is equal to or less than a predetermined value, a forecast for maintenance instructions is issued. The control apparatus which performs is provided.
[Selection] Figure 1

Description

  The present invention relates to an absorption refrigerator, and more particularly to an absorption refrigerator capable of constantly monitoring COP and maintaining COP at a certain level or higher.

In general, an absorption refrigerating machine that includes a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber and that connects these pipes to form a circulation path for an absorbing liquid and a refrigerant is known. Absorption refrigerators are used for central air conditioning in office buildings, for example.
Conventionally, as such an absorption refrigerator, for example, a pressure adjusting means and an intermediate regenerator are provided in an absorption solution line that communicates a high temperature regenerator and a low temperature regenerator or an absorption solution line that communicates a low temperature regenerator and an absorber. The intermediate regenerator exchanges sensible heat and latent heat between the fluid supplied from the external heat source and the absorbing solution flowing in the absorbing solution line, and measures the outlet temperature of the cold / hot water and the temperature of the high temperature regenerator. What is disclosed is provided with a temperature measuring means and a fuel supply amount control mechanism for adjusting the amount of high-quality fuel supplied to the burner for high-quality fuel combustion based on the temperature of the cold / hot water outlet and the temperature of the high-temperature regenerator. (For example, refer to Patent Document 1).

Japanese Patent No. 3114850

However, in the conventional technology, it has not been possible to determine whether or not the performance of the absorption chiller tends to be reduced.
For this reason, it has been impossible to take appropriate measures against the tendency to decrease in performance and to maintain the performance at a certain level.

Further, in the absorption refrigerator, it is required to maintain COP (Coefficient of Performance: “coefficient of performance”) above a certain level.
However, conventionally, COP is not directly monitored, and a system for monitoring COP has been desired.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an absorption refrigerator that can constantly monitor COP and maintain COP at a certain level or higher.

  In order to achieve the above object, the present invention comprises a high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber, and these are connected by piping to form absorption circuits and refrigerant circulation paths, respectively. When the COP is calculated and the COP increase / decrease rate is calculated from the calculated COP and the assumed COP during the cooling operation in the type refrigerator, and the average COP increase / decrease rate for one month is determined to be equal to or less than a predetermined value And a control device that issues a maintenance instruction forecast.

  According to this, when the control device determines that the average COP increase / decrease rate is equal to or less than a predetermined value, the maintenance instruction forecast is issued, so the COP is constantly monitored and appropriate action is taken by the forecast announcement. As a result, the COP can be kept above a certain level.

  According to the present invention, the COP can be maintained at a certain level or more by constantly monitoring the COP and performing an appropriate response by issuing a forecast.

The schematic block diagram of the absorption refrigerator which concerns on this embodiment. The block diagram which shows the control structure of this embodiment. The partial load diagram which shows the relationship between cooling capacity and COP. The flowchart which shows operation | movement of this embodiment.

A first aspect of the present invention is an absorption refrigerator comprising a high temperature regenerator, a low temperature regenerator, an evaporator, a condenser and an absorber, which are connected to each other to form a circulation path for an absorbing liquid and a refrigerant. When the COP is calculated during the cooling operation, the COP increase / decrease rate is calculated from the calculated COP and the assumed COP. A control device for issuing a report is provided.
According to this, when the control device determines that the average COP increase / decrease rate is equal to or less than a predetermined value, the maintenance instruction forecast is issued, so the COP is constantly monitored and appropriate action is taken by the forecast announcement. As a result, the COP can be kept above a certain level.

In the second invention, the control device calculates the assumed COP based on a preset relationship between the cooling capacity and the COP.
According to this, it is possible to easily calculate the assumed COP based on the relationship between the preset cooling capacity and the COP.

In a third aspect of the invention, the control device calculates a COP during heating operation, calculates a COP increase / decrease rate from the calculated COP and the assumed COP, and an average COP increase / decrease rate for one month is less than a predetermined value. If it is determined that a maintenance instruction is issued, a forecast for a maintenance instruction is issued.
According to this, even during the heating operation, the COP can be maintained at a certain level or more by constantly monitoring the COP and taking an appropriate response by issuing a forecast.

According to a fourth aspect of the invention, the control device issues a notification prompting confirmation of the contamination of the cooling water pipe when performing the prediction notification of the maintenance instruction.
According to this, since the confirmation of the contamination of the cooling water pipe is presented as a factor of decreasing the COP increase / decrease rate, the maintenance worker can appropriately cope with the forecast notification.

According to a fifth aspect of the invention, the control device issues a notification that prompts confirmation of a decrease in the degree of vacuum when performing the forecast notification of the maintenance instruction.
According to this, since the confirmation of the decrease in the degree of vacuum is presented as a factor that the COP increase / decrease rate is decreasing, the maintenance worker can appropriately cope with the forecast notification.

According to a sixth aspect of the invention, the control device issues a notification for urging confirmation of the operating state of the device, except for the case of issuing a notification for confirming the contamination of the cooling water pipe and the decrease in the degree of vacuum.
According to this, since the confirmation of the operation state of the device is presented as a factor that the COP increase / decrease rate is decreasing, the maintenance worker can appropriately cope with the forecast notification.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an absorption refrigerator according to the present embodiment. The absorption refrigerator 100 is an absorption chiller / heater that uses water as a refrigerant and an aqueous lithium bromide (LiBr) solution as an absorption liquid, and heats the absorption liquid with gas fuel.

As shown in FIG. 1, the absorption refrigerator 100 includes an evaporator 1, an absorber 2 provided in parallel with the evaporator 1, and an evaporator absorber body 3 that houses the evaporator 1 and the absorber 2. A high temperature regenerator 5 having a gas burner 4, a low temperature regenerator 6, a condenser 7 arranged in parallel with the low temperature regenerator 6, and a low temperature regenerator condensing the low temperature regenerator 6 and the condenser 7. A device body 8 is provided.
The absorption refrigerator 100 includes a low-temperature heat exchanger 12, a high-temperature heat exchanger 13, a refrigerant drain heat recovery unit 17, a rare absorption liquid pump 45, a concentrated absorption liquid pump 47, and a refrigerant pump 48. These devices are connected to each other through absorption liquid pipes 21 to 25 and refrigerant pipes 31 to 35 to form a circulation path.

The evaporator 1 is provided with a cold water pipe 14 for circulatingly supplying brine that has exchanged heat with the refrigerant in the evaporator 1 to a heat load (not shown) (for example, an air conditioner). A partially formed heat transfer tube 14 </ b> A is arranged in the evaporator 1.
The absorber 2 and the condenser 7 are provided with cooling water pipes 15 for sequentially passing cooling water through the absorber 2 and the condenser 7, and each heat transfer pipe 15 </ b> A formed in a part of the cooling water pipe 15. , 15B are arranged in the absorber 2 and the condenser 7, respectively.

The absorber 2 has a function of absorbing the refrigerant vapor evaporated in the evaporator 1 into the absorption liquid and maintaining the pressure in the evaporator absorber body 3 in a high vacuum state. In the lower part of the absorber 2, a rare absorption liquid reservoir 2A is formed, in which a rare absorption liquid diluted by absorbing refrigerant vapor is accumulated, and the rare absorption liquid reservoir 2A has a rare absorption liquid pump 45. One end of the liquid pipe 21 is connected. The rare absorbent liquid pipe 21 includes a branched rare absorbent liquid pipe 21A that branches on the downstream side of the rare absorbent liquid pump 45.
After passing through the refrigerant drain heat recovery unit 17, the branched diluted absorbent pipe 21 </ b> A joins the diluted absorbent pipe 21 again on the downstream side of the low-temperature heat exchanger 12 of the diluted absorbent pipe 21. The other end of the rare absorbent tube 21 passes through the high temperature heat exchanger 13 and then opens to the gas layer portion 5B located above the heat exchange portion 5A formed in the high temperature regenerator 5.
The rare absorption liquid pipe 21 is branched into the second branch pipe 21B on the downstream side of the low-temperature heat exchanger 12, and the second branch pipe 21B opens into the low-temperature regenerator 6.

  The high-temperature regenerator 5 is configured by housing the gas burner 4 in a shell 60, and a heat exchanging unit 5 </ b> A that heats and regenerates the absorbing liquid using the flame of the gas burner 4 as a heat source is formed above the gas burner 4. An exhaust path 40 through which the exhaust gas burned by the gas burner 4 flows is connected to the heat exchange section 5A, and an exhaust gas heat exchanger 41 is provided in the exhaust path 40. The gas burner 4 is connected to a gas pipe 61 to which fuel gas is supplied and an intake pipe 63 to which air from the blower 62 is supplied. The gas pipe 61 and the intake pipe 63 are connected to fuel gas and air. A control valve 64 is provided for controlling the amount. The gas pipe 61 is provided with a gas flow meter 65.

On the side of the heat exchanging unit 5A, an intermediate absorbing liquid reservoir 5C is formed in which the intermediate absorbing liquid that has been heated and regenerated by the heat exchanging unit 5A and then flows out of the heat exchanging unit 5A is accumulated. One end of a second intermediate absorption liquid pipe 23 is connected to the lower end of the intermediate absorption liquid reservoir 5C, and a high temperature heat exchanger 13 is provided in the second intermediate absorption liquid pipe 23. The high-temperature heat exchanger 13 heats the absorption liquid flowing in the rare absorption liquid pipe 21 with the high-temperature intermediate absorption liquid flowing out from the intermediate absorption liquid reservoir 5C, and the fuel consumption of the gas burner 4 in the high-temperature regenerator 5 The amount is reduced.
The other end of the second intermediate absorption liquid pipe 23 is connected to a concentrated absorption liquid pipe 25 that connects the low temperature regenerator 6 and the absorber 2. Further, the upstream side of the second intermediate absorption liquid pipe 23 at the high temperature heat exchanger 13 and the absorber 2 are connected by an absorption liquid pipe 24 with an on-off valve V1 interposed therebetween.

The low temperature regenerator 6 uses the refrigerant vapor separated in the high temperature regenerator 5 as a heat source to heat and regenerate the absorption liquid stored in the absorption liquid reservoir 6A formed in the low temperature regenerator 6, and the absorption liquid reservoir 6A. The heat transfer tube 31 </ b> A formed in a part of the refrigerant tube 31 extending from the upper end of the high temperature regenerator 5 to the bottom of the low temperature regenerator 6 is disposed. By circulating the refrigerant vapor through the refrigerant pipe 31, the heat of the refrigerant vapor is transmitted to the absorption liquid stored in the absorption liquid reservoir 6A via the heat transfer pipe 31A, and the absorption liquid is further concentrated.
One end of a concentrated absorption liquid pipe 25 is connected to the absorption liquid reservoir 6A of the low temperature regenerator 6, and the other end of the concentrated absorption liquid pipe 25 is provided at the upper part of the gas layer portion 2B of the absorber 2. Connected to 2C. The concentrated absorbent pipe 25 is provided with a concentrated absorbent pump 47 and a low-temperature heat exchanger 12. The low-temperature heat exchanger 12 heats the rare absorbent flowing through the rare absorbent pipe 21 with the warm heat of the concentrated absorbent flowing out from the absorbent reservoir 6B of the low-temperature regenerator 6.

Further, the concentrated absorbent pipe 25 is provided with a bypass pipe 27 that bypasses the concentrated absorbent pump 47 and the low-temperature heat exchanger 12.
When the operation of the concentrated absorbent pump 47 is stopped, the absorbent stored in the absorbent reservoir 6A of the low temperature regenerator 6 is supplied into the absorber 2 through the concentrated absorbent pipe 25 and the bypass pipe 27.

As described above, the gas layer portion 5 </ b> B of the high-temperature regenerator 5 and the refrigerant liquid reservoir 7 </ b> A formed at the bottom of the condenser 7 are connected by the refrigerant pipe 31. The refrigerant pipe 31 includes a heat transfer pipe 31 </ b> A and a refrigerant drain heat recovery unit 17 that are piped to the absorption liquid reservoir 6 </ b> A of the low-temperature regenerator 6. The upstream side of the heat transfer pipe 31A of the refrigerant pipe 31 and the gas layer portion 2B of the absorber 2 are connected by a refrigerant pipe 32 having an on-off valve V2.
In addition, one end of a refrigerant pipe 34 through which the refrigerant flowing out from the refrigerant liquid pool 7A flows is connected to the refrigerant liquid pool 7A of the condenser 7, and the other end of the refrigerant pipe 34 is a U-seal portion 34A that is curved downward. It is connected to the gas layer part 1A of the evaporator 1 via.
Below the evaporator 1 is formed a refrigerant liquid reservoir 1B in which the liquefied refrigerant is accumulated. It is connected by a refrigerant pipe 35 to intervene.

Further, the cold water pipe 14 is provided with a cold water inlet temperature sensor 80 that detects the temperature of the cold water inlet side that flows through the cold water pipe 14 and a cold water outlet temperature sensor 81 that detects the temperature of the cold water outlet side.
In addition, a pipe 14B that connects the inlet side and the outlet side of the cold water pipe 14 is provided, and a cold water differential pressure sensor 82 that detects a pressure difference between the inlet side and the outlet side of the cold water pipe 14 is provided in the pipe 14B. It has been.
Further, a cooling water inlet temperature sensor 83 that detects the temperature of the cooling water inlet side is provided on the inlet side of the cooling water pipe 15.

Further, the absorption refrigerator 100 of the present embodiment includes an extraction device 70, and the extraction device 70 includes a tank 71. An extraction pipe 72 communicating with the gas layer 2 </ b> B of the absorber 2 is connected to the upper portion of the tank 71. A return pipe 73 communicating with the lower side of the absorber 2 is connected to the bottom of the tank 71. Further, an absorption liquid pipe 75 connected to the rare absorption liquid pipe 21 via an ejector pump 74 is connected to the upper portion of the tank 71.
Then, by driving the ejector pump 74, the rare absorbing liquid in the rare absorbing liquid pipe 21 is taken into the tank 71 through the absorbing liquid pipe 75. Due to the rare absorption liquid flowing in the absorption liquid pipe 75, the inside of the tank 71 becomes negative pressure, thereby extracting not only the non-condensable gas stored in the upper part of the absorber 2, but also the refrigerant vapor, the vaporized absorption liquid, and the like. It is guided to the upper side of the tank 71 through the trachea 72.

  Among the gases guided to the tank 71, the refrigerant vapor and the vaporized absorption liquid are absorbed and absorbed in the absorption liquid stored below the tank 71, but the non-condensable gas cannot be dissolved in the absorption liquid. It is stored above the tank 71. Then, the absorbing liquid accumulated below the tank 71 is returned to the absorber 3 through the return pipe 73.

Next, the control configuration of this embodiment will be described.
FIG. 2 is a block diagram showing a control configuration of the present embodiment.
As shown in FIG. 2, the absorption refrigerator 100 according to the present embodiment includes a controller 50, and the controller 50 includes a control device 51. The control device 51 centrally controls each part of the absorption chiller 100, and includes a CPU as a calculation execution unit, a basic control program that can be executed by the CPU, and a ROM that stores predetermined data in a nonvolatile manner. A memory 52 such as a RAM for storing predetermined data in a volatile manner and other peripheral circuits are provided.
The control device 51 is configured to receive detection signals from the cold water inlet temperature sensor 80, the cold water outlet temperature sensor 81, the cold water differential pressure sensor 82, and the gas flow meter 65, respectively.
The controller 50 includes a timer 53, an operation unit 54, and a notification unit 55.

  The control device 51 of the controller 50 controls the fuel control valve 64 of the gas burner 4 of the absorption refrigeration machine 100, thereby performing combustion control by the gas burner 4, as well as the rare absorbent pump 45, the concentrated absorbent pump 47, and the refrigerant pump. 48 is configured to perform drive control. Further, the control device 51 of the controller 50 performs inverter control of the rare absorbent pump 45, the concentrated absorbent pump 47, and the refrigerant pump 48, whereby the flow rates of the rare absorbent pump 45, the concentrated absorbent pump 47, and the refrigerant pump 48 are controlled. It is configured to perform control. The control device 51 is configured to perform opening / closing control of the valves 28, V1, and V2.

  Further, the controller 50 is configured to be able to communicate with the remote monitoring system 90, and is configured to send various refrigerator data acquired by the control device 51 of the controller 50 to the remote monitoring system 90.

In the present embodiment, when the cooling operation is started, the control device 51 detects the cold water inlet temperature by the cold water inlet temperature sensor 80 and detects the cold water outlet temperature by the cold water outlet temperature sensor 81. Further, the control device 51 detects the cold water differential pressure value by the cold water differential pressure sensor 82 and also detects the gas flow rate and the gas heat generation amount in the gas burner 4. The gas flow rate is detected by a gas flow meter 65.
And the control apparatus 51 calculates COP at the time of air_conditionaing | cooling operation based on the following formula | equation.
COP = (cold water inlet temperature-cold water outlet temperature) x cold water flow rate rated value x (cold water differential pressure value ÷ rated cold water differential pressure value) 0.5 ÷ (gas flow rate x gas heating value)
Since the chilled water differential pressure value and the chilled water flow rate have a certain relationship, the chilled water flow rate can be obtained by calculating the 0.5th power of the chilled water differential pressure value with respect to the rated chilled water differential pressure value.

Next, the control device 51 calculates an assumed COP of the absorption chiller 100.
FIG. 3 is a partial load diagram showing the relationship of COP to cooling capacity.
As shown in FIG. 3, since there is a certain relationship between the cooling capacity and the COP, the assumed COP is calculated based on the cooling water inlet temperature detected by the cooling water inlet temperature sensor 83 and the cooling capacity. . In this case, the assumed COP can be easily calculated by setting in advance an approximate expression based on the relationship between the cooling capacity and the COP shown in FIG.

After calculating the COP and the assumed COP, the control device 51 obtains the COP increase / decrease rate based on the following equation.
COP increase / decrease rate = COP calculation value / Assumed COP calculation value x 100 (%)
The calculation of the COP increase / decrease rate is performed, for example, every predetermined time such as every hour, and the control device 51 obtains the average value of the calculated COP increase / decrease rates.
The control device 51 determines whether the average COP increase / decrease rate is equal to or greater than a predetermined value once a month, for example, at the end of the month.

In this embodiment, when the COP increase / decrease rate is 90% or less, that is, when the COP decrease rate exceeds 10%, it is determined that the COP of the absorption chiller 100 is deteriorated. Has been.
In the present embodiment, when the COP increase / decrease rate is 90% or less, it is determined that the COP has deteriorated. However, the value of the COP increase / decrease rate is not limited to this, and absorption It can set suitably according to the capability of the type refrigerator 100, etc.

When it is determined that the COP increase / decrease rate is 90% or less, the control device 51 performs control so as to issue a forecast notification instructing maintenance. For example, the maintenance instruction forecast is issued by displaying the maintenance instruction on the notification unit 55.
When the controller 51 determines that the COP increase / decrease rate is 90% or less, the controller 50 transmits the information to the remote monitoring system 90, and the remote monitoring system 90 issues a maintenance instruction forecast. May be.

  As a factor that the COP is considered to be deteriorated, for example, the internal contamination of the cooling water pipe 15 may be generated. When the control for performing the forecast notification regarding the internal contamination of the cooling water pipe 15 is performed, the confirmation of the contamination in the cooling water piping is urged when the prediction notification of the cooling water contamination is issued. Instruct the maintenance as follows.

As other factors, for example, the inside of the absorption chiller 100 is normally operated at a pressure lower than the atmosphere, but the internal pressure of the absorption chiller 100 increases and the degree of vacuum decreases. COP is considered to deteriorate. In order to determine whether or not the degree of vacuum is reduced, for example, an extraction device is attached to the absorber 2, and when the internal pressure of the absorption refrigerator 100 increases, the extraction pressure inside the extraction device is increased. Will increase. Therefore, when it is determined by the vacuum level detection means that the extraction pressure of the extraction device has increased, it can be determined that the vacuum level has decreased.
In this case, when it is determined that the degree of vacuum inside the absorption chiller 100 is lowered, the control device 51 issues a maintenance instruction so as to prompt confirmation of the factor that the degree of vacuum is lowered.
In addition, in the absorption refrigeration machine 100, when the control for performing the forecast notification of the vacuum reduction is performed, the forecast notification due to the increase in the amount of gas used and the forecast notification of the vacuum reduction are issued simultaneously. If it is reported, a warning may be issued to prompt confirmation of a decrease in the degree of vacuum.

Furthermore, when the internal contamination of the cooling water pipe 15 and the decrease in the degree of vacuum are not confirmed, the control device 51 issues a maintenance instruction so as to prompt confirmation of the operation state of each device in the absorption refrigerator 100.
When the forecast notification of the maintenance instruction is issued, the maintenance operator of the absorption chiller 100 performs maintenance of the absorption chiller 100 according to the maintenance instruction.
When the COP increase / decrease rate becomes higher than 90% due to the maintenance, the control device 51 transmits the contents and result of the maintenance to the remote monitoring system 90, and the remote monitoring system 90 generates a remote monitoring report. Inform the user of the treatment details and results.

Here, in the present embodiment, the control device 51 is configured to determine whether or not the operation of the absorption chiller 100 is stable.
Based on the cold water outlet temperature and the cold water set temperature detected by the cold water outlet temperature sensor 81, the control device 51 calculates the cold water temperature difference by the cold water outlet temperature-the cold water set temperature.
Then, the control device 51 determines whether or not the cold water temperature difference is within a predetermined range. The predetermined range is set to an arbitrary temperature within a range of ± 0.1 ° C. to ± 0.5 ° C., for example. The control device 51 determines whether or not the state where the chilled water temperature difference is within a predetermined range continues for a predetermined time (for example, 10 minutes). If the control device 51 determines that the predetermined time continues, a stable cooling or heating operation is performed. Is determined (first condition).

  Moreover, the control apparatus 51 calculates the cold water inlet / outlet temperature difference which is the difference between the cold water inlet temperature and the cold water outlet temperature. The control device 51 calculates the difference between the current chilled water inlet / outlet temperature difference and the chilled water inlet / outlet temperature acquired immediately before, and determines whether this temperature difference is within a predetermined range. The control device 51 determines whether or not the state where the temperature difference is within a predetermined range continues for a predetermined time (for example, 10 minutes), and when it is determined that the temperature difference continues for a predetermined time, the cooling or heating stable operation is performed. It is determined that it is being performed (second condition).

  Further, the control device 51 calculates the refrigeration capacity ratio from the chilled water temperature difference and the chilled water flow rate value, and the difference between the current refrigeration capacity ratio every predetermined time (for example, 1 minute) and the refrigeration capacity ratio acquired immediately before is within a predetermined range. It is judged whether it is in. The control device 51 determines whether or not the state where the difference in the refrigeration capacity ratio is within a predetermined range continues for a predetermined time (for example, 10 minutes). It is determined that stable operation is being performed (third condition).

  And the control apparatus 51 is comprised so that it may judge that the driving | running state of the absorption refrigeration machine 100 is stable, when it is judged that the 3rd conditions are satisfy | filled from the above-mentioned 1st conditions. .

Next, the operation of this embodiment will be described.
During the cooling operation, brine (for example, cold water) is circulated and supplied to a heat load (not shown) via the cold water pipe 14. The control device 51 heats the absorption chiller 100 so that the outlet side temperature of the brine evaporator 1 (temperature detected by the cold water outlet temperature sensor 81) becomes a predetermined set temperature, for example, 7 ° C. Is controlled.
Specifically, the control device 51 starts all the pumps 45, 47, and 48 and controls the combustion of gas in the gas burner 4, so that the temperature of the brine measured by the cold water outlet temperature sensor 81 is predetermined. The heating power of the gas burner 4 is controlled so as to be 7 ° C.

In this case, the rare absorbing liquid from the absorber 2 is heated via the rare absorbing liquid pipe 21 by the rare absorbing liquid pump 45 via the low temperature heat exchanger 12 and the high temperature heat exchanger 13 or the exhaust gas heat exchanger 41. It is sent to the high temperature regenerator 5.
The absorption liquid sent to the high temperature regenerator 5 is heated by the flame generated by the gas burner 4 and the high-temperature combustion gas in the high temperature regenerator 5, so that the refrigerant in the absorption liquid evaporates and separates. The intermediate absorption liquid whose concentration has been increased by evaporating and separating the refrigerant in the high temperature regenerator 5 is sent to the concentrated absorption liquid pipe 25 via the high temperature heat exchanger 13 and merged with the absorption liquid via the low temperature regenerator 6. .

  On the other hand, the absorption liquid sent to the low-temperature regenerator 6 is heated by the high-temperature refrigerant vapor supplied from the high-temperature regenerator 5 through the refrigerant pipe 31 and flowing into the heat transfer pipe 31A, and the refrigerant is further separated to have a concentration. The concentrated absorbent is combined with the absorbent through the high-temperature regenerator 5 and is sent to the absorber 2 through the low-temperature heat exchanger 12 by the concentrated absorbent pump 47. The concentrated sprayer 2C Scattered from.

The refrigerant separated and generated by the low-temperature regenerator 6 enters the condenser 7, condenses, and accumulates in the refrigerant liquid reservoir 7A. When a large amount of refrigerant liquid accumulates in the refrigerant liquid reservoir 7A, the refrigerant liquid flows out of the refrigerant liquid reservoir 7A, enters the evaporator 1 via the refrigerant pipe 34, and is pumped and dispersed by the operation of the refrigerant pump 48. It is spread | dispersed on 14 A of heat exchanger tubes of the cold water pipe 14 from the container 1C.
Since the refrigerant liquid sprayed on the heat transfer tube 14A evaporates by removing the heat of vaporization from the brine passing through the heat transfer tube 14A, the brine passing through the heat transfer tube 14A is cooled, and the brine thus lowered in temperature Cooling operation such as cooling is performed by supplying the heat load from the cold water pipe 14.
Then, the refrigerant evaporated in the evaporator 1 enters the absorber 2, is absorbed by the concentrated absorbent supplied from the low temperature regenerator 6 and sprayed from above, and accumulates in the rare absorbent reservoir 2A of the absorber 2, and is rarely used. The circulation conveyed to the high temperature regenerator 5 by the absorption liquid pump 45 is repeated.

Next, the control operation according to the present embodiment will be described with reference to the flowchart shown in FIG.
In the present embodiment, when the cooling operation is started (ST1), the control device 51 determines whether or not the operation state of the absorption chiller 100 is stable (ST2).
And when the control apparatus 51 judges that the operation state of the absorption refrigeration machine 100 is stable (ST2: YES), based on the cold water inlet temperature, the cold water outlet temperature, the cold water differential pressure value, and the gas flow rate, The current COP is calculated (ST3).
Subsequently, the control device 51 calculates an assumed COP (ST4).
Control device 51 calculates a COP increase / decrease rate based on the calculated COP and assumed COP (ST5).

Next, after calculating the COP increase / decrease rate, the control device 51 obtains an average value of the COP increase / decrease rate (ST6).
At the end of the month (ST7: YES), control device 51 determines whether the average COP increase / decrease rate is 90% or less (ST8).

When the average COP increase / decrease rate is 90% or less (ST8: YES), the control device 51 determines that the COP has deteriorated, and issues a forecast notification instructing maintenance (ST9).
When the forecast notification of the maintenance instruction is issued, the maintenance operator of the absorption chiller 100 performs maintenance of the absorption chiller 100 according to the maintenance instruction.

As described above, in the present embodiment, during the cooling operation, the COP is calculated, the COP increase / decrease rate is calculated from the calculated COP and the assumed COP, and the average COP increase / decrease rate for one month is predetermined. When it is determined that it is the following, a control device 51 that issues a forecast for a maintenance instruction is provided.
According to this, when the control device 51 determines that the average COP increase / decrease rate is equal to or less than the predetermined value, the maintenance instruction forecast is issued. Therefore, the COP is constantly monitored, and the appropriate action is taken by the forecast announcement. By doing so, the COP can be kept above a certain level.

In the present embodiment, the control device 51 calculates an assumed COP based on a preset relationship between the cooling capacity and the COP.
According to this, it is possible to easily calculate the assumed COP based on the relationship between the preset cooling capacity and the COP.

Further, in the present embodiment, the control device 51 calculates the COP during the heating operation, calculates the COP increase / decrease rate from the calculated COP and the assumed COP, and the average COP increase / decrease rate for one month becomes When it is determined that the value is less than the predetermined value, a maintenance instruction forecast is issued.
According to this, even during the heating operation, the COP can be maintained at a certain level or more by constantly monitoring the COP and taking an appropriate response by issuing a forecast.

Further, in the present embodiment, the control device 51 issues a notification that prompts confirmation of the contamination of the cooling water pipe 15 when performing the prediction notification of the maintenance instruction.
According to this, since the confirmation of the contamination of the cooling water pipe 15 is presented as a factor that the COP increase / decrease rate is decreasing, the maintenance worker can appropriately cope with the forecast notification.

Further, in the present embodiment, the control device 51 issues a notification prompting confirmation of a decrease in the degree of vacuum when performing a prediction notification of the maintenance instruction.
According to this, since the confirmation of the decrease in the degree of vacuum is presented as a factor that the COP increase / decrease rate is decreasing, the maintenance worker can appropriately cope with the forecast notification.

Further, in the present embodiment, the control device 51 issues a notification that prompts confirmation of the operating state of the device, except for a notification that prompts confirmation of contamination of the cooling water pipe 15 and a decrease in the degree of vacuum.
According to this, since the confirmation of the operation state of the device is presented as a factor that the COP increase / decrease rate is decreasing, the maintenance worker can appropriately cope with the forecast notification.

In addition, this embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
For example, in the present embodiment, the control during the cooling operation has been described. Similarly, during the heating operation, the COP increase / decrease rate is calculated based on the COP and the assumed COP to determine whether or not the COP is appropriate. It may be.

  Moreover, although the structure provided with the gas burner 4 which burns and burns fuel gas as a heating means which heats absorption liquid in the high temperature regenerator 5 was demonstrated, it is not limited to this, For example, kerosene or A heavy oil It is good also as a structure provided with the gas burner which burns, or a structure heated using warm heat, such as a vapor | steam and exhaust gas.

DESCRIPTION OF SYMBOLS 1 Evaporator 2 Absorber 3 Absorber 4 Gas burner 5 High temperature regenerator 6 Low temperature regenerator 7 Condenser 45 Diluted absorption liquid pump 47 Concentrated absorption liquid pump 48 Refrigerant pump 50 Controller 51 Control device 52 Memory 55 Notification part 64 Fuel control valve 65 Gas flow meter 70 Extraction device 80 Chilled water inlet temperature sensor 81 Chilled water outlet temperature sensor 82 Chilled water differential pressure sensor 83 Chilled water inlet temperature sensor 90 Remote monitoring system 100 Absorption chiller

Claims (6)

In the absorption refrigerating machine comprising a high temperature regenerator, a low temperature regenerator, an evaporator, a condenser and an absorber, and connecting these pipes to form a circulation path for the absorbing liquid and the refrigerant,
When the COP is calculated during the cooling operation, the COP increase / decrease rate is calculated from the calculated COP and the assumed COP. An absorption chiller comprising a control device for issuing a notification.   2. The absorption chiller according to claim 1, wherein the control device calculates the assumed COP based on a relationship between a preset cooling capacity and the COP.   The control device calculates the COP during the heating operation, calculates the COP increase / decrease rate from the calculated COP and the assumed COP, and determines that the average COP increase / decrease rate for one month is equal to or less than a predetermined value. The absorption refrigeration machine according to claim 1 or 2, wherein a maintenance instruction forecast is issued.   The absorption according to any one of claims 1 to 3, wherein the control device issues a warning that prompts confirmation of a contamination of the cooling water pipe when the forecast notification of the maintenance instruction is issued. Type refrigerator.   The absorption according to any one of claims 1 to 3, wherein the control device issues a warning prompting confirmation of a decrease in the degree of vacuum when the forecast notification of the maintenance instruction is issued. Type refrigerator.   2. The control device according to claim 1, wherein the control device issues a notification that prompts confirmation of an operation state of the device, except for a notification that prompts confirmation of contamination of the cooling water pipe and a decrease in the degree of vacuum. 4. The absorption refrigerator according to any one of 3 above.

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