JP2018077013A - Absorption type refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorption type refrigerating machine capable of continuing an operation by keeping lowering of refrigeration capacity to a minimum, even in the case where the machine is operating at capacity equal to or greater than rated capacity.SOLUTION: An absorption type refrigerating machine includes a high temperature regenerator 5, a low temperature regenerator 6, an evaporator 1, a condenser 7 and an absorber 2, and circulation paths of an absorbing solution and a refrigerant are formed respectively by connecting these by piping. It also includes a control device 51 which performs control in such a manner that, during a cooling operation, in the case where an internal temperature of the high temperature regenerator 5 is determined to have exceeded a predetermined temperature (160°C), opening of a fuel control valve 64 is reduced by a predetermined amount, and in the case where the internal temperature of the high temperature regenerator 5 is determined to have become lower than a predetermined temperature (158°C), the opening of the fuel control valve 64 is increased by a predetermined amount.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an absorption refrigeration machine, and more particularly to an absorption refrigeration machine capable of continuing operation while minimizing a decrease in refrigeration capacity even when operating at a capacity exceeding a rated capacity.

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 a high quality fuel supply amount to the high quality fuel combustion burner 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, the exhaust heat utilization rate is further increased to reduce the consumption of high-quality fuel, and the capacity is drastically reduced even when the temperature of the high-temperature regenerator rises without generating an ineffective refrigerant. There is no.
Here, in the absorption chiller, in recent years, the equipment that shows the rated output at the normal load is used instead of the equipment that shows the rated output at the time of high load. In order to exhibit an output exceeding the rating and to operate at the rated output during a normal load, a small absorption refrigerator having a lower rated output than the conventional one has been used.

  Also, the internal temperature of the high-temperature regenerator is controlled to be constant at all times, but if the internal temperature of the high-temperature regenerator rises excessively when operating at a capacity exceeding the rated output, abnormal avoidance control is performed. Is done. This abnormality avoidance control is control for uniformly reducing the amount of combustion by the gas burner for an arbitrary time. For this reason, there is a problem that the refrigeration capacity is reduced more than necessary during the abnormality avoidance control, and the abnormality avoidance control is performed again because the combustion amount of the gas burner returns to the maximum value after the abnormality avoidance control ends. There is a problem that the operation of the absorption refrigerator may not be performed normally.

  The present invention has been made in view of the above circumstances, and an absorption chiller capable of continuing operation while minimizing a decrease in refrigeration capacity even when operating at a capacity exceeding the rated capacity. It is intended to provide.

  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 internal temperature of the high temperature regenerator exceeds a predetermined temperature during cooling operation, the opening degree of the fuel control valve of the gas burner is reduced by a predetermined amount, and the internal temperature of the high temperature regenerator is predetermined When it is determined that the temperature is lower than the temperature, a control device is provided for controlling the opening degree of the fuel control valve to be increased by a predetermined amount.

  According to this, even when operating at a capacity exceeding the rated capacity, it is possible to minimize the decrease in the combustion amount by the gas burner and to suppress the rapid decrease in the refrigeration capacity by the absorption refrigerator.

  According to the present invention, even when operating at a capacity exceeding the rated capacity, the reduction in the combustion amount by the gas burner can be minimized, and the refrigerating capacity by the absorption refrigerator can be maintained as much as possible. it can.

Schematic configuration diagram of an absorption refrigerator according to the present embodiment The block diagram which shows the control structure of this embodiment Flow chart showing the operation of this embodiment The conceptual diagram which shows the change of the internal temperature of the high temperature regenerator by 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 it is determined that the internal temperature of the high-temperature regenerator exceeds a predetermined temperature during cooling operation, the opening degree of the fuel control valve of the gas burner is reduced by a predetermined amount, and the internal temperature of the high-temperature regenerator becomes lower than the predetermined temperature. When the determination is made, a control device is provided for controlling the opening of the fuel control valve to increase by a predetermined amount.
According to this, even when operating at a capacity exceeding the rated capacity, the reduction of the combustion amount by the gas burner can be minimized, and the refrigerating capacity by the absorption refrigerator can be maintained as much as possible. .

In a second aspect of the invention, the absorption refrigerator includes 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 the absorbing liquid and the refrigerant. When it is determined that the concentration of the concentrated absorbent exceeds a predetermined concentration during the cooling operation, the opening degree of the fuel control valve of the gas burner is decreased by a predetermined amount, and the concentration of the concentrated absorbent is determined to be lower than the predetermined concentration. And a control device for controlling the opening degree of the fuel control valve to increase by a predetermined amount.
According to this, even when operating at a capacity exceeding the rated capacity, the reduction of the combustion amount by the gas burner can be minimized, and the refrigerating capacity by the absorption refrigerator can be maintained as much as possible. .

According to a third aspect of the invention, the control for reducing the opening of the fuel control valve by a predetermined amount by the control device and the control for increasing the opening of the fuel control valve by a predetermined amount reduce the opening of the fuel control valve. The amount of opening when the opening of the fuel control valve is increased is controlled to be smaller than the amount of opening.
According to this, when the internal temperature of the high temperature regenerator exceeds a predetermined temperature, the internal temperature of the high temperature regenerator can be quickly reduced, and the internal temperature of the high temperature regenerator becomes lower than the predetermined temperature. The internal temperature of the high temperature regenerator can be gradually increased.

In a fourth aspect of the invention, the control device controls the opening degree of the fuel control valve even during a heating operation.
According to this, even during the heating operation, the internal temperature of the high-temperature regenerator can be controlled within a predetermined range, the reduction of the combustion amount by the gas burner can be minimized, and the freezing by the absorption refrigerator can be performed. Ability can be maintained as much as possible.

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 fuel control valve 64 for controlling the amount of the fuel is provided.

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 through the first intermediate absorption liquid pipe 22 with the heat of the high-temperature intermediate absorption liquid flowing out from the intermediate absorption liquid reservoir 5C, and the gas burner 4 in the high-temperature regenerator 5 is heated. It aims to reduce fuel consumption.
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 31A and a refrigerant drain heat recovery unit 17 piped to the absorption liquid reservoir 6A of the low-temperature regenerator 6, and the upstream side of the heat transfer pipe 31A of the refrigerant pipe 31 and the gas layer of the absorber 2 The part 2B is 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. The refrigerant liquid reservoir 1B and the spreader 1C disposed above the gas layer portion 1A of the evaporator 1 are provided by a refrigerant pump 48. It is connected by a refrigerant pipe 35 to intervene.

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.

  In the present embodiment, a temperature sensor 36 that detects the internal temperature of the high-temperature regenerator 5 is provided. A concentration sensor 37 that detects the concentration of the concentrated absorbent is provided downstream of the concentrated absorbent tube 25 from the low-temperature heat exchanger 12.

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, and other peripheral circuits.
The control device 51 is configured to receive detection signals from the temperature sensor 36 and the concentration sensor 37, 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 intermediate absorbent pump 46, and the rich absorption. The liquid pump 47 and the refrigerant pump 48 are configured to perform drive control. Further, the controller 51 of the controller 50 performs inverter control of the rare absorbent pump 45, the intermediate absorbent pump 46, the concentrated absorbent pump 47, and the refrigerant pump 48, so that the rare absorbent pump 45 and the intermediate absorbent pump 46 are controlled. The flow rate is controlled by the concentrated absorbent pump 47 and the refrigerant pump 48. The control device 51 is configured to perform opening / closing control of the valves 28, V1, and V2.

In general, for the absorption refrigerator 100, for example, a device with a rated output that can cope with a so-called high load that is operated under conditions in which the outside air is extremely hot, such as in summer, is used. And at the time of normal load other than the time of high load, it is driving | operating with the capability of about 70 to 80% of the rated output of the absorption refrigeration machine 100. FIG. Since operation exceeding the rated output is only performed for about 5% of the time throughout the year, if a device with a rated output that can handle high loads is installed, the rated output will not be used for about 95% of the year. Therefore, the absorption refrigerator 100 cannot be used to the maximum, and the installation cost of the equipment is increased.
Therefore, the absorption refrigeration machine 100 of the present embodiment uses equipment that can handle normal loads other than high loads, and at the time of high loads, increases the capacity of the cooling water pump and the cold water pump and the capacity of the gas burner 4. It is made to respond by raising.

Specifically, the absorption chiller 100 according to the present embodiment is a power-saving type capable of exhibiting a rated output by reducing the cooling water flow rate by 30 to 35% with respect to the standard absorption chiller 100. The absorption refrigerator 100 is used. Further, the gas burner 4 is configured to increase its capacity to increase the amount of combustion. During rated operation, the fuel control valve 64 of the gas burner 4 is controlled so that the capacity of the gas burner 4 is reduced to, for example, 90%. It is comprised so that it can burn by a capability and can drive | operate. That is, the absorption refrigerator 100 of the present embodiment uses a device that exhibits a rated output at a normal load, not a device that exhibits a rated output at a high load. As a result, the capacity more than the rated output is exhibited at the time of a high load, and the operation is performed at the rated output at the time of a normal load. Therefore, it is possible to use the small absorption refrigerator 100 having a lower rated output than before.
Further, the cooling water pump is configured to be driven at a cooling water flow rate of about 70% of the maximum cooling water flow rate that can be supplied during rated operation. That is, assuming that the maximum capacity is 100%, the motor is driven with a capacity of about 70% during rated operation.

The control device 51 acquires the internal temperature of the high temperature regenerator 5 detected by the temperature sensor 36 during cooling, and determines whether or not the internal temperature of the high temperature regenerator 5 is a predetermined temperature. For example, during the cooling operation, the internal temperature of the high-temperature regenerator 5 is set to 160 ° C., and the control device 51 maintains this state for a predetermined time when the internal temperature of the high-temperature regenerator 5 exceeds 160 ° C. It is determined whether or not it continues (for example, 60 seconds).
When the controller 51 determines that the state in which the internal temperature exceeds 160 ° C. continues for a predetermined time, the controller 51 controls the fuel control valve 64 so that the opening of the fuel control valve 64 is reduced by 5% from the current opening. .
Further, the controller 51 determines whether or not the internal temperature of the high-temperature regenerator 5 exceeds 160 ° C. when a predetermined time (for example, 10 minutes) has elapsed after the opening of the fuel control valve 64 is decreased. Judging. When the internal temperature of the high temperature regenerator 5 exceeds 160 ° C., the opening degree of the fuel control valve 64 is controlled to be further reduced by 5%.

Further, after the opening degree of the fuel control valve 64 is decreased, the control device 51 reduces the opening degree of the fuel control valve 64 from the current opening degree when the internal temperature of the high temperature regenerator 5 falls below 158 ° C. Control to increase by 2%. On the other hand, when the internal temperature of the high-temperature regenerator 5 is between 158 ° C. and 160 ° C., control is performed to maintain the current maximum value of the fuel control valve 64.
Although the set temperature of the internal temperature of the high temperature regenerator 5 is set to 160 ° C., it is not limited to this and can be set arbitrarily. Moreover, although it has set as 158 degreeC, ie, setting temperature -2 degreeC, as a fall temperature with respect to setting temperature, it is not limited to this, It can set arbitrarily.
In addition, regarding the opening degree control of the fuel control valve 64, the opening degree decrease is set to 5% and the opening degree increase is set to 2%. However, the present invention is not limited to this and can be arbitrarily set.

In the present embodiment, the degree of opening of the fuel control valve 64 is controlled based on the internal temperature of the high-temperature regenerator 5, but the present invention is not limited to this. For example, the concentration of the concentrated absorbent may be detected by the concentration sensor 37, and the opening degree of the fuel control valve 64 may be controlled based on this concentration.
In this case, the control device 51 acquires the concentration of the concentrated absorbent detected by the concentration sensor 37 during the cooling operation, and determines whether or not the concentration of the concentrated absorbent is a predetermined concentration. For example, the concentration of the concentrated absorbent is set to 64 wt%, and the control device 51 continues this state for a predetermined time (for example, 60 seconds) when the concentration of the concentrated absorbent exceeds 64 wt%. Judge whether or not.

When the controller 51 determines that the state in which the concentration of the concentrated absorbent exceeds 64 wt% continues for a predetermined time, the controller 51 decreases the opening of the fuel control valve 64 by 5% from the current opening. To control.
Further, the control device 51 determines whether or not the concentration of the concentrated absorbent exceeds 64 wt% when a predetermined time (for example, 10 minutes) has elapsed after the opening of the fuel control valve 64 is decreased. To do. When the concentration of the concentrated absorbent exceeds 64 wt%, the opening degree of the fuel control valve 64 is controlled to be further reduced by 5%.
Further, the control device 51 opens the fuel control valve 64 when the concentration of the concentrated absorbent decreases below 63 wt% (64 wt% −1.0 wt%) after the opening degree of the fuel control valve 64 is decreased. The degree is controlled to increase by 2% from the current opening. On the other hand, when the internal temperature of the high-temperature regenerator 5 is between 63 wt% and 64 wt%, control is performed to maintain the current maximum value of the fuel control valve 64.

Moreover, in this embodiment, although the control which the control apparatus 51 performs at the time of air_conditionaing | cooling operation is demonstrated, you may make it perform the same control also at the time of heating operation.
In this case, the control device 51 determines whether or not the internal temperature of the high-temperature regenerator 5 detected by the temperature sensor 36 is a predetermined temperature. For example, during the heating operation, the internal temperature of the high-temperature regenerator 5 is set to 120 ° C., and the controller 51 continues the state where the internal temperature of the high-temperature regenerator 5 exceeds 120 ° C. for a predetermined time. When it is determined that the opening degree of the fuel control valve 64 is controlled to be reduced by 5% from the current opening degree.
Further, the controller 51 reduces the fuel control valve 64 when the internal temperature of the high-temperature regenerator 5 exceeds 120 ° C. when a predetermined time has elapsed after decreasing the opening of the fuel control valve 64. Is controlled so as to further reduce the opening degree of 5%.
In addition, the controller 51 reduces the opening degree of the fuel control valve 64 from the current opening degree when the internal temperature of the high-temperature regenerator 5 drops below 118 ° C. after reducing the opening degree of the fuel control valve 64. Control to increase by 2%. On the other hand, when the internal temperature of the high-temperature regenerator 5 is between 118 ° C. and 120 ° C., the current maximum value of the fuel control valve 64 is controlled to be maintained.
In addition, it can set arbitrarily also regarding the density | concentration setting of a thick absorption liquid, and the temperature setting at the time of heating operation.

Next, the operation of this embodiment will be described.
During cooling operation such as cooling, 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 36) 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 the gas in the gas burner 4 by controlling the fuel control valve 64, whereby the high-temperature regenerator using the temperature sensor 36. The heating power of the gas burner 4 is controlled so that the internal temperature of 5 becomes a predetermined 160 ° 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, and 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, control according to the present embodiment will be described with reference to a flowchart shown in FIG.
First, when the cooling operation is started and the combustion of the gas burner 4 is started (ST1), the control device 51 acquires the internal temperature of the high temperature regenerator 5 detected by the temperature sensor 36, and the high temperature regenerator 5 It is determined whether or not the internal temperature exceeds 160 ° C. (ST2).
If it is determined that the internal temperature of the high-temperature regenerator 5 exceeds 160 ° C. (ST2: YES), it is determined whether or not this state continues for 60 seconds (ST3).

If the controller 51 determines that the internal temperature exceeds 160 ° C. for 60 seconds (ST3: YES), the opening of the fuel control valve 64 is reduced by 5% from the current opening. (ST4).
Further, the control device 51 determines whether or not the internal temperature of the high-temperature regenerator 5 exceeds 160 ° C. when 10 minutes elapses after the opening degree of the fuel control valve 64 is decreased (ST5). . If the internal temperature of the high-temperature regenerator 5 exceeds 160 ° C. (ST5: YES), the opening degree of the fuel control valve 64 is controlled to be further reduced by 5% (ST4).

Further, when the internal temperature of the high-temperature regenerator 5 has decreased below 158 ° C. (ST7: YES), the control device 51 reduces the opening of the fuel control valve 64 after the opening of the fuel control valve 64 is decreased. Control is performed to increase the current opening by 2% (ST8).
When 10 minutes have elapsed after increasing the opening degree of the fuel control valve 64, the control device 51 determines whether or not the internal temperature of the high-temperature regenerator 5 is between 158 ° C. and 160 ° C. ( ST1) When the internal temperature is between 158 ° C. and 160 ° C. (ST10: YES), control is performed so as to maintain the current maximum value of the fuel control valve 64 (ST11).

FIG. 4 is a conceptual diagram showing changes in the internal temperature of the high-temperature regenerator 5 when such control by the control device 51 is performed.
As shown in FIG. 4, when the internal temperature of the high-temperature regenerator 5 exceeds 160 ° C., the internal temperature of the high-temperature regenerator 5 is reduced by performing control to reduce the opening degree of the fuel control valve 64 by 5%. However, when the internal temperature of the high temperature regenerator 5 becomes lower than 158 ° C., the internal temperature of the high temperature regenerator 5 can be increased by performing control to increase the opening degree of the fuel control valve 64 by 2%. .
By controlling in this way, the reduction of the combustion amount by the gas burner 4 can be stopped to the minimum necessary, and the refrigerating capacity by the absorption refrigerator 100 can be maintained as much as possible.

As described above, in this embodiment, the high-temperature regenerator 5, the low-temperature regenerator 6, the evaporator 1, the condenser 7, and the absorber 2 are provided, and these are connected by piping to provide a circulation path for the absorbing liquid and the refrigerant. In the cooling operation, when it is determined that the internal temperature of the high temperature regenerator 5 exceeds a predetermined temperature (160 ° C.), the opening degree of the fuel control valve 64 is decreased by a predetermined amount, and the high temperature regenerator 5 When it is determined that the internal temperature is lower than a predetermined temperature (158 ° C.), a control device 51 is provided for controlling the opening degree of the fuel control valve 64 to increase by a predetermined amount.
According to this, even when operating at a capacity exceeding the rated capacity, the reduction of the combustion amount by the gas burner 4 can be stopped to the minimum necessary, and the refrigeration capacity by the absorption chiller 100 can be maintained as much as possible. Can do.

Further, in the present embodiment, the control for reducing the opening degree of the fuel control valve 64 by the control device 51 by a predetermined amount and the control for increasing the opening degree of the fuel control valve 64 by a predetermined amount are performed by controlling the opening degree of the fuel control valve 64. The amount of opening when increasing the opening of the fuel control valve 64 is controlled to be smaller than the amount of opening when reducing.
According to this, when the internal temperature of the high temperature regenerator 5 exceeds a predetermined temperature, the internal temperature of the high temperature regenerator 5 can be quickly reduced, and the internal temperature of the high temperature regenerator 5 is lower than the predetermined temperature. In this case, the internal temperature of the high temperature regenerator 5 can be gradually increased.

Moreover, in this embodiment, the control apparatus 51 controls the opening degree of the fuel control valve 64 also at the time of heating operation.
According to this, even during the heating operation, the internal temperature of the high-temperature regenerator 5 can be controlled within a predetermined range, and the reduction in the combustion amount by the gas burner 4 can be stopped to the minimum necessary. The refrigeration capacity by 100 can be maintained as much as possible.

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 this embodiment, although the structure provided with the gas burner 4 which heats by burning 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, A configuration including a gas burner for burning kerosene or A heavy oil, or a configuration for heating using warm heat such as steam or exhaust gas may be used.

DESCRIPTION OF SYMBOLS 1 Evaporator 2 Absorber 4 Gas burner 5 High temperature regenerator 6 Low temperature regenerator 7 Condenser 12 Low temperature heat exchanger 13 High temperature heat exchanger 14 Cold water pipe 15 Cooling water pipe 16 Waste hot water supply pipe 21 Rare absorption liquid pipe 36 Temperature sensor 37 Concentration Sensor 45 Rare absorption liquid pump 47 Concentrated absorption liquid pump 48 Refrigerant pump 50 Controller 51 Control device 52 Memory 64 Fuel control valve 70 Extraction device 100 Absorption type refrigerator

Claims (4)

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 it is determined that the internal temperature of the high-temperature regenerator exceeds a predetermined temperature during cooling operation, the opening degree of the fuel control valve of the gas burner is reduced by a predetermined amount, and the internal temperature of the high-temperature regenerator becomes lower than the predetermined temperature. An absorption refrigeration machine comprising: a control device that, when judged, increases the degree of opening of the fuel control valve by a predetermined amount. 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 it is determined that the concentration of the concentrated absorbent exceeds a predetermined concentration during the cooling operation, the opening degree of the fuel control valve of the gas burner is decreased by a predetermined amount, and the concentration of the concentrated absorbent is determined to be lower than the predetermined concentration. In addition, the absorption chiller further includes a control device that controls the opening degree of the fuel control valve to be increased by a predetermined amount.   The control by the control device for reducing the opening of the fuel control valve by a predetermined amount and the control for increasing the opening of the fuel control valve by a predetermined amount are based on the opening amount when the opening of the fuel control valve is reduced. The absorption refrigerator according to claim 1 or 2, wherein the amount of opening when the opening of the fuel control valve is increased is controlled to be small.   The absorption chiller according to any one of claims 1 to 3, wherein the control device performs opening control of the fuel control valve even during heating operation.

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