JP6871015B2 - Absorption refrigeration system - Google Patents

Description

The present invention relates to an absorption refrigeration system.

Conventionally, an absorption refrigeration system including an absorption chiller that obtains cold water used in an external device by a circulation cycle using an evaporator, an absorber, a regenerator, and a condenser has been known. In this type of absorption refrigeration system, the temperature of the solution may be lower than the temperature of the solution during operation when the absorption refrigerating machine is started. Therefore, at startup, the amount of heat used in the regenerator may be larger than that during steady operation. Further, when the temperature of the cooling water for cooling the absorption chiller is low, there is a problem that the heat consumption of the absorption chiller increases.

For example, Patent Document 1 discloses an absorption heat pump that can be operated even when the temperature of the supplied cooling water is low. In this absorption heat pump, a cooling water heater that raises the temperature of the cooling water by giving heat other than the heat taken from the refrigerant vapor to the cooling water supplied to the condenser, and a cooling water heater increase the amount of heat. It is equipped with a control device that adjusts and maintains the concentration of the concentrated solution so that it does not exceed a predetermined concentration.

Japanese Unexamined Patent Publication No. 2015-183967

As described above, when the absorption chiller consumes more heat than the heat source side, the heat source temperature drops below the operating temperature of the absorption chiller and is absorbed until the heat source temperature rises. The chiller may be shut down. In this case, the process is stopped until the heat source temperature rises again, and this cycle is repeated until the cooling water temperature and the solution temperature rise. Therefore, there is a problem that the temperature on the heat source side fluctuates greatly, and in the worst case, the heat source temperature does not recover and the absorption chiller cannot be started.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an absorption refrigeration system capable of starting an absorption chiller even in an environment where the cooling water temperature is low.

In order to solve such a problem, the present invention provides an absorption refrigeration system that supplies a cooled refrigerant to an external device that operates using the refrigerant. This absorption refrigeration system includes an absorption refrigerating machine that cools the refrigerant through a circulation cycle consisting of an evaporator, a absorber, a regenerator and a condenser, and a heat source that heats the heat medium supplied to the regenerator of the absorption chiller. It has a cooling tower that circulates cooling water between the condenser and absorber of the absorption chiller, and a controller that controls the absorption refrigeration system, and the controller is based on a preset determination temperature. Te when determining the low temperature state of the cooling water, have rows control for reducing the regenerative capacity of the regenerator, after completion of the control for reducing the regenerative capacity of the regenerator, the cooling amount of the cooling water by the cooling tower It intends line control to decrease.

Here, in the present invention, it is preferable that the control for lowering the regeneration ability of the regenerator limits the amount of heat medium supplied from the heat source to the regenerator.

The present invention also provides an absorption refrigeration system that supplies a cooled refrigerant to an external device that operates using the refrigerant. This absorption refrigeration system includes an absorption refrigerating machine that cools the refrigerant through a circulation cycle consisting of an evaporator, an absorber, a regenerator and a condenser, and a heat source that heats the heat medium supplied to the regenerator of the absorption chiller. It has a cooling tower that circulates cooling water between the condenser of the absorption chiller and the absorber, and a controller that controls the absorption refrigeration system. The controller has a preset temperature of the cooling water. When the low temperature state of the cooling water, which is lower than the first determination temperature, is determined, the amount of heat medium supplied from the heat source to the regenerator is limited, and the absorption liquid and the refrigerant are between the regenerator and the absorber. By stopping the solution pump that circulates the solution containing and, the regeneration capacity of the regenerator is controlled to decrease, and after determining the low temperature state of the cooling water, a second determination in which the temperature of the heat medium is preset is determined. When the optimum temperature state of the heat medium above the temperature is determined, the operation of the solution pump is started, and after the operation of the solution pump is started, the temperature of the cooling water is set in advance to be equal to or higher than the first determination temperature and the first determination is made. When the first temperature rise state of the cooling water, which is higher than the temperature and lower than the third determination temperature, is determined, the temperature of the solution is raised, and the cooling water temperature is equal to or higher than the third determination temperature. When the second temperature rise state is determined, the amount of the solution supplied to the absorber is adjusted so that the evaporator reaches a predetermined temperature state according to the temperature of the refrigerant supplied from the evaporator to the external device. , Control to adjust dynamically.

According to the present invention, the absorption chiller can be appropriately started even in an environment where the cooling water temperature is low.

Configuration diagram schematically showing the absorption refrigeration system according to this embodiment Configuration diagram schematically showing the configuration of the absorption chiller A flowchart showing a control method of the absorption refrigeration system according to the present embodiment.

FIG. 1 is a configuration diagram schematically showing the absorption refrigeration system 1 according to the present embodiment. The absorption chiller system 1 according to the present embodiment heats the rare solution of the absorption chiller 21 by utilizing the heat of the heat source, and the first system 10, the second system 20, and the third system 30 are used. And the system controller 40.

The first system 10 is a system for recovering heat from a heat source, and includes an engine 11, a heat exchanger 12, an exhaust heat flow path 13, a radiator 14, and an engine-side three-way valve 15.

The engine 11 drives the generator 16, and is, for example, a reciprocating engine. In the absorption refrigeration system 1, the engine 11 corresponds to a heat source, and the exhaust heat of the engine 11 is recovered in the first system 10.

The heat exchanger 12 heats the heat medium by exchanging heat between the exhaust heat of the engine 11 and the heat medium supplied to the second system 20.

The exhaust heat flow path 13 is a pipe that circulates a heat medium from the engine 11 to the engine 11 again via the heat exchanger 12. Of the heat exhaust flow paths 13, the flow path from the heat exchanger 12 to the engine 11 is referred to as a first heat exhaust flow path 13a, and the flow path from the engine 11 to the heat exchanger 12 is referred to as a second heat exhaust flow path 13b. Further, the heat exhaust flow path 13 includes a third heat exhaust flow path 13c via the radiator 14, one end of the third heat exhaust flow path 13c is on the upstream side of the first heat exhaust flow path 13a, and the other end is on the upstream side. , Is connected to the downstream side of the first heat exhaust flow path 13a.

The radiator 14 is provided in the first heat exhaust flow path 13a, and dissipates heat from the heat medium from the heat exchanger 12 to the engine 11.

The engine-side three-way valve 15 is arranged at a connection point between the third heat exhaust flow path 13c and the first heat exhaust flow path 13a. When the opening degree of the three-way valve 15 on the engine side is fully opened, the heat medium from the heat exchanger 12 bypasses the radiator 14 and flows to the engine 11. On the other hand, as the opening degree of the engine-side three-way valve 15 is limited, the proportion of the heat medium flowing to the radiator 14 increases.

The second system 20 is for obtaining cold water used in the indoor unit 31, which will be described later, and includes an absorption chiller 21, a heat medium flow path 22, and a heat medium pump 23. In the present embodiment, the indoor unit 31 uses cold water, but the indoor unit 31 is not limited to the cold water, and other refrigerants may be used.

FIG. 2 is a configuration diagram schematically showing the configuration of the absorption chiller 21. The absorption chiller 21 obtains cold water through a circulation cycle of a regenerator, a condenser, an evaporator and an absorber. The absorption chiller 21 includes a regenerator 101, a condenser 102, an evaporator 103, and an absorber 104. Further, in the absorption chiller 21, a cooling tower 25 and a cooling water flow path 26 are combined.

The regenerator 101 heats a dilute solution (a solution having a low concentration of the absorbing liquid) in which a refrigerant (for example, water) and lithium bromide (LiBr) serving as an absorbing liquid are mixed. Hereinafter, the vaporized refrigerant is referred to as "refrigerant vapor", and the liquefied refrigerant is referred to as "liquid refrigerant". A heat medium flow path 22 is arranged in the regenerator 101, and a dilute solution is sprayed and heated on the heat medium flow path 22. The regenerator 101 generates refrigerant vapor and a concentrated solution (a solution having a high concentration of an absorbing liquid) by releasing vapor from the dilute solution by heating. A dilute solution is supplied to the regenerator 101 from the absorber 104 via the solution flow path 29 (first solution flow path 29a).

The condenser 102 liquefies the refrigerant vapor supplied from the regenerator 101. A heat transfer tube 102a through which the cooling water cooled by the cooling tower 25 flows is provided in the condenser 102. A cooling water flow path 26 is connected to the heat transfer tube 102a so that the cooling water can circulate between the heat transfer tube 102a and the cooling tower 25. The evaporated refrigerant vapor is liquefied by the cooling water in the heat transfer tube 102a. The liquid refrigerant liquefied in the condenser 102 is supplied to the evaporator 103.

The evaporator 103 evaporates the liquid refrigerant. A chilled water flow path 32 connected to the indoor unit 31, which will be described later, is provided in the evaporator 103. Cold water warmed by the indoor unit 31 flows through the cold water flow path 32. Further, the inside of the evaporator 103 is in a vacuum state. Therefore, the evaporation temperature of water as a refrigerant is about 5 ° C. Therefore, the liquid refrigerant sprayed on the chilled water flow path 32 evaporates depending on the temperature of the chilled water flow path 32. On the other hand, the temperature of the cold water in the cold water flow path 32 is deprived by the evaporation of the liquid refrigerant. As a result, the cold water flowing in the cold water flow path 32 is cooled, and the cooled cold water is supplied to the indoor unit 31.

The absorber 104 absorbs the refrigerant vaporized in the evaporator 103. A concentrated solution is supplied to the absorber 104 from the regenerator 101 via the solution flow path 29 (second solution flow path 29b), and the evaporated refrigerant is absorbed by the concentrated solution to generate a dilute solution. A heat transfer tube 104a through which the cooling water cooled by the cooling tower 25 flows is provided in the absorber 104. A cooling water flow path 26 is connected to the heat transfer tube 104a so that the cooling water can circulate between the heat transfer tube 104a and the cooling tower 25. The endothermic heat generated by the absorption of the refrigerant in the concentrated solution is removed by the cooling water flowing through the heat transfer tube 104a. The dilute solution whose concentration has decreased due to absorption of the refrigerant is supplied to the regenerator 101 by the solution pump 104b. The heat transfer tube 104a is connected to the heat transfer tube 102a of the condenser 102 in order to share the cooling water of the cooling tower 25 with the condenser 102.

In the present embodiment, the second solution flow path 29b is connected to a solution bypass flow path 29c that bypasses the heat transfer tube 104a and supplies the concentrated solution supplied to the absorber 104 to the lower side of the heat transfer tube 104a. ing. The solution bypass flow path 29c is provided with a solution bypass valve 29c1 that switches the supply state (supply or cutoff) of the concentrated solution by opening and closing the solution bypass flow path 29c. When the solution bypass valve 29c1 is closed, the concentrated solution supplied from the regenerator 101 passes through the heat transfer tube 104a, so that the absorber 104 has a high absorption capacity. On the other hand, when the solution bypass valve 29c1 is open, the concentrated solution supplied from the regenerator 101 bypasses the heat transfer tube 104a at an increased rate. That is, by limiting the solution flowing into the absorber 104, it is possible to suppress the temperature drop of the evaporator 103.

The cooling tower 25 supplies cooling water to the absorption chiller 21 and cools the cooling water warmed by the absorption chiller 21. The cooling tower 25 has, for example, a tank at the bottom for accommodating cooling water. Water is supplied to this tank by moving the float up and down, and the tank stores a certain amount of cooling water. Further, the cooling tower 25 has a fan 25a and a heat exchange portion 25b arranged below the fan 25a above the cooling tower 25. The cooling water returned from the absorption chiller 21 is sprayed on the heat exchange section 25b and is cooled by passing through the heat exchange section 25b. The cooling water cooled by the heat exchange unit 25b is stored in the tank.

The cooling water flow path 26 is a pipe for circulating cooling water from the cooling tower 25 to the cooling tower 25 again via the absorber 104 and the condenser 102 of the absorption chiller 21. Of these, the flow path from the cooling tower 25 to the absorption chiller 21 is referred to as a first cooling water flow path 26a, and the flow path from the absorption chiller 21 to the cooling tower 25 is referred to as a second cooling water flow path 26b.

The first cooling water flow path 26a is connected to the bottom portion (bottom portion of the tank) of the cooling tower 25, and the cooling water pump 27 is provided in the first cooling water flow path 26a. The cooling water pump 27 serves as a power source for circulating the cooling water. The second cooling water flow path 26b is connected to the upper part of the cooling tower 25 (between the fan 25a and the heat exchange portion 25b).

Further, the second cooling water flow path 26b is connected to a cooling water bypass flow path 26c that supplies the cooling water returning to the cooling tower 25 by bypassing the heat exchange unit 25b. A cooling water three-way valve 28 is arranged at a connection point between the second cooling water flow path 26b and the cooling water bypass flow path 26c. When the opening degree of the cooling water three-way valve 28 is fully opened, the cooling water from the absorption chiller 21 flows to the upper part of the cooling tower 25 and is supplied to the heat exchange section 25b. On the other hand, as the opening degree of the cooling water three-way valve 28 is limited, the proportion of the cooling water flowing into the cooling water bypass flow path 26c increases, and the cooling capacity of the cooling tower 25 also decreases.

Further, the absorption chiller 21 includes a control unit 105. The control unit 105 includes a CPU (Central Processing Unit) and controls the entire absorption chiller 21. Further, the control unit 105 is configured to change the control content of the absorption chiller 21 based on a control signal from the system controller 40 described later.

With reference to FIGS. 1 and 2, the heat medium flow path 22 is a pipe for circulating the heat medium from the heat exchanger 12 to the heat exchanger 12 again via the regenerator 101 of the absorption chiller 21. Of these, the flow path from the heat exchanger 12 to the regenerator 101 of the absorption chiller 21 is referred to as the first heat medium flow path 22a, and the flow path from the regenerator 101 of the absorption chiller 21 to the heat exchanger 12 Is referred to as a second heat medium flow path 22b. Further, the heat medium flow path 22 includes a third heat medium flow path 22c that bypasses the absorption chiller 21, and one end of the third heat medium flow path 22c is connected to the first heat medium flow path 22a. The other end is connected to the second heat medium flow path 22b.

A heat medium pump 23 is provided in the first heat medium flow path 22a of the heat medium flow paths 22. The heat medium pump 23 serves as a power source for circulating the heat medium.

Further, a heat medium three-way valve 24 is provided at a connection point between the second heat medium flow path 22b and the third heat medium flow path 22c. When the opening degree of the heat medium three-way valve 24 is fully opened, the heat medium from the heat exchanger 12 flows to the heat exchanger 12 via the regenerator 101. On the other hand, as the opening degree of the heat medium three-way valve 24 is limited, the ratio of the heat medium flowing into the third heat medium flow path 22c, that is, the ratio of the heat medium bypassing the regenerator 101 increases. That is, when the heat medium three-way valve 24 is set on the regenerator 101 side (when fully open), the entire amount of the heat medium from the heat exchanger 12 is supplied to the regenerator 101, so that the regenerator 101 is expensive. It becomes a reproduction ability. On the other hand, when the heat medium three-way valve 24 is set to the bypass side (when the opening degree is limited), the supply of the heat medium to the regenerator 101 is restricted, so that the regenerative capacity of the regenerator 101 is reduced. It will be.

The third system 30 supplies the chilled water obtained by the absorption chiller 21 to the indoor unit 31, and includes the indoor unit 31, the chilled water flow path 32, and the chilled water pump 33.

The indoor unit 31 is connected to the cold water flow path 32 and is provided indoors. The indoor unit 31 is an air conditioner and exchanges heat between the cold water supplied from the absorption chiller 21 and the air taken in from the room. By this heat exchange, heat is taken from the air to cold water and the air is cooled. The indoor unit 31 blows the cooled air into the room.

The chilled water flow path 32 is a pipe that circulates chilled water from the indoor unit 31 to the indoor unit 31 again via the evaporator 103 of the absorption chiller 21. Of these, the flow path from the evaporator 103 of the absorption chiller 21 to the indoor unit 31 is referred to as the first chilled water flow path 32a, and the flow path from the indoor unit 31 to the evaporator 103 of the absorption chiller 21 is the second. It is referred to as a chilled water flow path 32b.

The chilled water pump 33 is provided in the second chilled water flow path 32b of the chilled water flow path 32, and serves as a power source for circulating chilled water.

The system controller 40 controls the entire absorption refrigeration system 1. Signals from various sensors and the like are input to the system controller 40 as control inputs. The system controller 40 performs various calculations based on the control input, and outputs control outputs according to the calculation results to each part of the absorption chiller system 1. As the system controller 40, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used.

The heat medium inlet temperature sensor 41 is a sensor that detects the temperature of the heat medium (heat medium inlet temperature) supplied to the regenerator 101 of the absorption chiller 21, and sends a signal according to the heat medium inlet temperature to the system controller 40. Output to.

The heat medium outlet temperature sensor 42 is a sensor that detects the temperature of the heat medium (heat medium outlet temperature) flowing out from the regenerator 101 of the absorption chiller 21, and sends a signal corresponding to the heat medium outlet temperature to the system controller 40. Output.

The chilled water outlet temperature sensor 43 is a sensor that detects the temperature of chilled water (cold water outlet temperature) supplied from the absorption chiller 21 to the indoor unit 31, and outputs a signal corresponding to the chilled water outlet temperature to the system controller 40.

The cooling water outlet temperature sensor 44 is a sensor that detects the temperature of the cooling water flowing out from the cooling tower 25 (cooling water outlet temperature), and outputs a signal corresponding to the cooling water outlet temperature to the system controller 40.

As one of the features of the present embodiment, when the system controller 40 determines the low temperature state of the cooling water based on the predetermined determination temperature when the absorption chiller 21 is started, the system controller 40 transfers the cooling water to the regenerator 101. Control is performed to limit the amount of heat input.

Next, the control method of the absorption chilling system 1 according to the present embodiment will be described. FIG. 3 is a flowchart showing a control method of the absorption chilling system 1 according to the present embodiment. The process shown in this flowchart relates to the start-up operation of the absorption chiller 21 and is executed by the system controller 40 triggered by the start of operation of the absorption chiller system 1.

First, in steps 1 (S1) to 3 (S3), the system controller 40 operates the chilled water pump 33, the heat medium pump 23, and the cooling water pump 27, respectively. Therefore, at this point, the solution pump 104b is not yet operated.

In step 4 (S4), the system controller 40 determines whether or not the cooling water outlet temperature is equal to or higher than the first determination temperature T1 based on the detection signal of the cooling water outlet temperature sensor 44. The first determination temperature T1 is for determining whether or not the cooling water is so low that it is necessary to limit the supply of the heat medium to the regenerator 101, and the optimum value is preset through experiments and simulations. (For example, 15 ° C). If the cooling water outlet temperature is equal to or higher than the first determination temperature T1, a positive determination is made in step 4, and the process proceeds to step 5 (S5). On the other hand, when the cooling water outlet temperature is smaller than the first determination temperature T1, a negative determination is made in step 4, and the process proceeds to step 6 (S6).

In step 5, the system controller 40 sets the heat medium three-way valve 24 to fully open. As a result, the heat medium from the heat exchanger 12 is supplied to the regenerator 101.

On the other hand, in step 6, the system controller 40 determines whether or not the heat medium inlet temperature supplied to the regenerator 101 is equal to or higher than the second determination temperature T2 based on the detection signal of the heat medium inlet temperature sensor 41. .. The second determination temperature T2 is a parameter for suppressing a sudden heat input from the heat medium to the regenerator 101, and an optimum value is preset through experiments and simulations (for example, the rated temperature −10 ° C. (for example). For example, 80 ° C.)). When the heat medium inlet temperature is equal to or higher than the second determination temperature T2, an affirmative determination is made in step 6 and the process proceeds to step 7 (S7). On the other hand, when the heat medium inlet temperature is smaller than the second determination temperature T2, a negative determination is made in step 6 and the process proceeds to step 5.

In step 7, the system controller 40 is set to a state in which the opening degree of the heat medium three-way valve 24 is limited. For example, the opening degree is set to 30% to 50%. This limits the supply of heat medium to the regenerator 101.

In step 8 (S8), the system controller 40 determines whether or not the heat medium inlet temperature supplied to the regenerator 101 is equal to or higher than the third determination temperature T3 based on the detection signal of the heat medium inlet temperature sensor 41. To do. When the operation of the solution pump 104b is started, heat is input from the heat medium, and an extreme temperature drop of the heat medium may occur. The third determination temperature T3 is for determining whether or not the solution pump 104b can be operated, and an optimum value is preset through experiments and simulations (for example, 65 ° C.). When the heat medium inlet temperature is equal to or higher than the third determination temperature T3, an affirmative determination is made in step 8 and the process proceeds to step 9 (S9). On the other hand, when the heat medium inlet temperature is smaller than the third determination temperature T3, a negative determination is made in step 8 and the process returns to step 8.

In step 9, the system controller 40 operates the solution pump 104b.

In step 10 (S10), the system controller 40 determines whether or not the cooling water outlet temperature is equal to or higher than the fourth determination temperature T4 based on the detection signal of the cooling water outlet temperature sensor 44. The fourth determination temperature T4 is for determining whether or not the cooling water outlet temperature has risen to a predetermined level through the operations from step 1 to step 9, and the optimum value is preset through experiments and simulations. (T1 <T4 (for example, 22 ° C.)). If the cooling water outlet temperature is equal to or higher than the fourth determination temperature T4, an affirmative determination is made in step 10 and the process proceeds to step 11 (S11). On the other hand, when the cooling water outlet temperature is smaller than the fourth determination temperature T4, a negative determination is made in step 10 and the process proceeds to step 13 (S13).

In step 11, the system controller 40 sets the cooling water three-way valve 28 to fully open. As a result, the cooling water from the absorption chiller 21 is cooled in the heat exchange section 25b of the cooling tower 25. Then, in step 12 (S12), the system controller 40 controls the solution bypass valve 29c1 in the automatic operation mode. This automatic operation mode is a control applied to the solution bypass valve 29c1 during the normal operation of the absorption chiller 21. In this control, the optimum evaporator temperature that defines the optimum temperature state of the evaporator 103 is set through experiments and simulations (for example, optimum evaporator temperature = chilled water outlet temperature-2 ° C.). The system controller 40 dynamically controls the opening degree of the solution bypass valve 29c1 so that the optimum evaporator temperature is obtained.

On the other hand, in step 13, the system controller 40 sets the cooling water three-way valve 28 to be fully closed. As a result, the cooling water supplied from the absorption chiller 21 flows into the cooling water bypass flow path 26c, and the degree of cooling of the cooling water decreases (the cooling capacity of the cooling tower 25 decreases). Then, in step 14 (S14), the system controller 40 controls the solution bypass valve 29c1 to open.

In step 15 (S15), the system controller 40 determines whether or not the cooling water outlet temperature is equal to or higher than the fifth determination temperature T5 based on the detection signal of the cooling water outlet temperature sensor 44. The fifth determination temperature T5 is for determining whether or not the cooling water outlet temperature has risen to a predetermined level through the operations from step 1 to step 14, and the optimum value is preset through experiments and simulations. (T4 <T5 (for example, 28 ° C.)). If the cooling water outlet temperature is equal to or higher than the fifth determination temperature T5, a positive determination is made in step 15 and the process proceeds to step 16 (S16). On the other hand, when the cooling water outlet temperature is smaller than the fifth determination temperature T5, a negative determination is made in step 15 and the process returns to step 15.

In step 16, the system controller 40 operates the fan 25a of the cooling tower 25.

When these series of processes are completed, the system controller 40 ends the start-up operation and shifts to the normal operation. In this start-up operation, the temperature of the cooling water is low (cooling water outlet temperature ≤ first determination temperature T1), and the temperature of the heat medium is within a certain temperature range up to the rated temperature. In this case (heat medium inlet temperature ≥ rated temperature −10 ° C.), the heat medium three-way valve 24 is controlled so that the entire amount of the heat medium is not supplied to the regenerator 101. As a result, the regenerating ability of the regenerating device 101 is lowered, so that sudden heat input from the heat medium to the regenerating device 101 is suppressed.

Further, in order to suppress an extreme temperature drop of the heat medium, the solution pump 104b is not operated when the heat medium inlet temperature is equal to or lower than the third determination temperature T3. As a result, the regenerating ability of the regenerating device 101 is lowered, so that sudden heat input from the heat medium to the regenerating device 101 is suppressed.

On the other hand, after the control for lowering the regeneration ability of the regenerator 101 is completed, the heat medium circulates, and the solution in which the absorbing liquid and the refrigerant are mixed circulates in the solution flow path 29 to input heat to the regenerator 101. Is started. In this case, the cooling water three-way valve 28 is controlled, and the cooling water circulates around the heat exchange portion 25b of the cooling tower 25. As a result, heat dissipation of the heat stored in the absorption chiller 21 by the cooling water is suppressed, and the temperature of the cooling water can be raised quickly.

Further, in the condenser 102, since the input heat is dissipated to the cooling water, the temperature of the cooling water can be quickly raised to a predetermined level. At this time, since the solution bypass valve 29c1 is opened, the amount of the concentrated solution passing through the heat transfer tube 104a of the absorber 104 is limited. As a result, the temperature drop of the evaporator 103 can be suppressed, so that the freezing of the refrigerant can be prevented.

Then, when the temperature of the cooling water rises to some extent, the cooling water three-way valve 28 is fully opened, whereby the cooling water is supplied to the heat exchange portion 25b of the cooling tower 25. The solution bypass valve 29c1 can also be switched to the normal automatic operation mode. In addition, when the temperature of the cooling water rises further, the fan 25a of the cooling tower 25 is operated. As a result, it is possible to shift to normal operation.

As described above, in the present embodiment, the absorption refrigeration system 1 is a system that supplies cooled cold water to the indoor unit 31 which is an external device operated by using cold water. The absorption chiller system 1 is supplied to the absorption chiller 21 that generates cold water by the circulation cycle of the evaporator 103, the absorber 104, the regenerator 101 and the condenser 102, and the regenerator 101 of the absorption chiller 21. A system that controls the absorption refrigerating system 1 and the cooling tower 25 that circulates cooling water between the engine 11 that is a heat source for heating the heat medium, the condenser 102 and the absorber 104 of the absorption chiller 21. It has a controller 40 and. In this case, the system controller 40 controls to reduce the regeneration ability of the regenerator 101 when the low temperature state of the cooling water is determined based on the preset first determination temperature T1.

According to this configuration, the amount of heat input to the regenerator 101 is limited by reducing the regenerating ability of the regenerator 101, so that a situation in which a large amount of heat is taken from the heat medium to the absorption chiller 21 is suppressed. can do. As a result, the situation where the heat medium temperature drops remarkably is suppressed, so that it is not necessary to stop the absorption chiller 21 until the heat medium temperature recovers. As a result, the absorption chiller 21 can be smoothly started even at a temperature of cooling water that cannot be normally started.

Further, in the present embodiment, the control for reducing the regeneration capacity of the regenerator 101 limits the amount of heat medium supplied to the regenerator 101 from the heat exchanger 12 that heats the heat medium by receiving the heat from the engine 11. It is a thing.

According to this method, the regeneration ability of the regenerator 101 can be reduced by limiting the amount of heat medium supplied to the regenerator 101. Thereby, the amount of heat input to the regenerator 101 can be appropriately limited. As a result, the absorption chiller 21 can be smoothly started even at a temperature of cooling water that cannot be normally started.

Further, the control for reducing the regeneration capacity of the regenerator 101 is to stop the solution pump 104b that circulates the solution between the regenerator 101 and the absorber 104.

According to this method, the circulation of the solution between the regenerator 101 and the absorber 104 is stopped, so that the regeneration ability of the regenerator 101 can be reduced. Thereby, the amount of heat input to the regenerator 101 can be appropriately limited. As a result, the absorption chiller 21 can be smoothly started even at a temperature of cooling water that cannot be normally started.

Further, in the present embodiment, the system controller 40 controls to reduce the amount of cooling water cooled by the cooling tower 25 after the control for reducing the regeneration ability of the regenerator 101 is completed.

According to this configuration, it is possible to suppress the heat input to the absorption chiller 21 from being dissipated to the cooling water, which can lead to an increase in the temperature of the solution. As a result, the start-up can be performed smoothly, the start-up time can be shortened, and the temperature fluctuation toward the engine 11 side can be suppressed.

Further, in the present embodiment, the system controller 40 limits the solution flowing into the absorber 104 after finishing the control for reducing the regeneration ability of the regenerator 101. Specifically, the solution bypass valve 29c1 is opened.

According to this configuration, the temperature drop of the evaporator 103 is suppressed, so that the temperature of the solution can be raised. This makes it possible to avoid crystallization of the solution. Further, since the temperature drop of the evaporator 103 is suppressed, freezing of the refrigerant can be avoided. As a result, it is possible to solve the problem that the absorption chiller 21 cannot be started due to the crystallization of the solution or the freezing of the refrigerant. As a result, the start-up time can be shortened because the start-up time can be smoothly performed, and the temperature fluctuation toward the engine 11 side can be suppressed.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and modifications may be made without departing from the spirit of the present invention.

In the present embodiment, an engine is exemplified as a heat source, but various engines can be used as long as it is a heat source. For example, the heat source may be a fuel cell or the like.

1 Absorption refrigeration system 10 1st system 11 Engine (heat source)
12 Heat exchanger 20 Second system 21 Absorption chiller 101 Regenerator 102 Condenser 103 Evaporator 104 Absorber 25 Cooling tower 30 Third system 31 Indoor unit 40 System controller (controller)

Claims (4)

In an absorption refrigeration system that supplies cooled refrigerant to external equipment that operates using refrigerant.
Absorption chillers that cool the refrigerant through a circulation cycle with evaporators, absorbers, regenerators and condensers,
And a heat source for heating the heating medium supplied to the regenerator of the absorption chiller,
A cooling tower for circulating the cooling water between the condenser and the absorber of the absorption refrigerator,
It has a controller that controls the absorption refrigeration system.
Wherein the controller, when determining the low temperature state of the cooling water based on preset determination temperature, the have line control for lowering the regenerative capacity of the regenerator, control for reducing the regenerative capacity of the regenerator after the completion of the absorption refrigeration system characterized in row Ukoto control to reduce the cooling amount of the cooling water by the cooling tower. The absorption refrigeration system according to claim 1, wherein the control for reducing the regeneration capacity of the regenerator limits the amount of heat medium supplied from the heat source to the regenerator. Claim 1 or 2 is characterized in that the control for reducing the regeneration capacity of the regenerator is to stop the solution pump that circulates the solution containing the absorbing liquid and the refrigerant between the regenerating device and the absorber. Absorption refrigeration system described in. In an absorption refrigeration system that supplies cooled refrigerant to external equipment that operates using refrigerant.
Absorption chillers that cool the refrigerant through a circulation cycle with evaporators, absorbers, regenerators and condensers,
A heat source for heating the heat medium supplied to the regenerator of the absorption chiller, and
A cooling tower that circulates cooling water between the condenser and the absorber of the absorption chiller, and
It has a controller that controls the absorption refrigeration system.
The controller
When the low temperature state of the cooling water in which the temperature of the cooling water is lower than the preset first determination temperature is determined, the amount of heat medium supplied from the heat source to the regenerator is limited, and the heat medium is limited. By stopping the solution pump that circulates the solution containing the absorbent liquid and the refrigerant between the regenerator and the absorber, the regeneration ability of the regenerator is controlled to be reduced.
After determining the low temperature state of the cooling water, if it is determined that the temperature of the heat medium is equal to or higher than the preset second determination temperature, the operation of the solution pump is started. ,
After the operation of the solution pump is started, the temperature of the cooling water is equal to or higher than the first determination temperature and is lower than the third determination temperature which is preset and higher than the first determination temperature. When the state is determined, the temperature of the solution is raised, and when the second temperature rise state of the cooling water at which the temperature of the cooling water is equal to or higher than the third determination temperature is determined, the absorption Control is performed to dynamically adjust the supply amount of the solution to the vessel so that the evaporator becomes a predetermined temperature state according to the temperature of the refrigerant supplied from the evaporator to the external device. Absorption-type refrigeration system featuring.

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