JP6820050B2 - Absorption chiller, control program and control method of absorption chiller - Google Patents

Description

The present invention relates to the absorption chiller, the control program and the control method of the absorption chiller, and particularly the absorption chiller, the control program and the absorption chiller for appropriately performing a concentration calculation based on pressure to determine the necessity of diluting the absorption liquid. Regarding the control method of the type refrigerator.

Absorption chillers such as absorption chillers and hot water machines that cool or heat the fluid to be temperature-controlled by the absorption cycle of the absorption liquid (solution) and the refrigerant are used in an operating state where the concentration of the absorption liquid is uneven at high temperatures. When stopping due to a decrease in load, etc., in order to prevent the absorption liquid from crystallizing, it is common to dilute the absorption liquid with a refrigerant and perform a dilution operation to make the concentration of the absorption liquid uniform for a certain period of time before stopping. Is the target. Solution concentration detection that detects the concentration of the solution in the high temperature regenerator as an absorption cold / hot water machine that eliminates the drawback of violating energy saving when the concentration of the solution is set to the highest concentration for a certain period of time during the dilution operation. When the means is provided and the absorption cold / hot water machine is stopped, dilution is started when the concentration of the solution detected by the solution concentration detecting means is equal to or higher than a predetermined value, and after the concentration of the solution becomes equal to or lower than a predetermined value, a predetermined time Only the residual operation of the solution pump is performed to finish the dilution (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 11-37595

When the absorption chiller is stopped, if the solution concentration is high to some extent and the solution is stopped without dilution, the solution will crystallize when the temperature of the solution drops to the crystal temperature. However, it takes some time for the temperature of the solution to drop to the crystal temperature. Therefore, when the concentration of the solution is equal to or higher than a predetermined value as in the absorption cold / hot water machine described in Patent Document 1, the dilution is started. Dilution will be performed even though there is time for the solution to crystallize, and if the absorption cold / hot water machine is restarted before the temperature drops to the crystal temperature, the energy required for dilution will be wasted and the solution will start up. It will take time. In order to eliminate such inconvenience, it is conceivable to continuously detect the solution concentration even after the absorption chiller is stopped and start the dilution when the detected concentration reaches the concentration required to dilute the solution. Be done. When calculating the concentration based on the pressure inside the canister, which has a more economical advantage in detecting the solution concentration, it has become impossible to calculate the appropriate concentration after the absorption chiller is stopped.

In view of the above problems, the present invention provides an absorption chiller, a control program, and a control method for the absorption chiller, which can appropriately perform a concentration calculation based on pressure to determine the necessity of diluting the absorption liquid. The purpose is.

In order to achieve the above object, the absorption chiller according to the first aspect of the present invention includes, for example, as shown in FIG. 1, an absorption liquid S and a refrigerant V formed by supplying a heating source 31. In the absorption chiller 1 that cools or heats the temperature-controlled fluid C by the absorption cycle of the above; the absorption liquid Sw that has absorbed the refrigerant Ve is heated by the heating source 31 to separate the refrigerant Vg from the absorption liquid Sw. With the regenerator 30 that increases the concentration of the absorption liquid Sw; with the regenerator pressure correlation value detection unit 52 that detects the pressure of the regenerator 30 or the physical quantity that correlates with the pressure of the regenerator 30; inside the absorption chiller 1 A solution pump 19 that flows the absorption liquid S so that the absorption liquid S circulates; a state in which the refrigerant liquid Vf is mixed in the systems 10, 18, 30, and 38 in which the absorption liquid S can circulate and a state in which the liquid Vf is not mixed are switched. Possible refrigerant liquid mixing possible part 70; When the absorption chiller 1 is stopped, the solution pump 19 does not mix the refrigerant liquid Vf into the systems 10, 18, 30, and 38 in which the absorption liquid S can circulate. The low heating operation is performed by reducing the amount of heat input to the regenerator 30 to a predetermined amount of heat while continuing the operation of the above, and calculation is performed based on the value detected by the regenerator pressure correlation value detection unit 52 during the low heating operation. The supply mechanism of the heating source 31, the solution pump 19, and the refrigerant liquid so as to stop the supply of the heating source 31 to the absorption chiller 1 when the calculated concentration, which is the concentration of the absorbed chiller S, is less than a predetermined value. A control device 60 for controlling the mixing possible unit 70 is provided.

With this configuration, the concentration of the absorbent solution is calculated based on the value detected by the regenerator pressure correlation value detector while performing low heating operation, so that the saturated state in the regenerator is maintained and the absorbent solution is supplied. The concentration can be appropriately grasped, and the necessity of diluting the absorbing solution can be appropriately determined.

Further, as shown in the absorption chiller according to the second aspect of the present invention, for example, with reference to FIG. 1, in the absorption chiller 1 according to the first aspect of the present invention, the control device 60 is low. When the calculated concentration does not fall below the predetermined value even after a predetermined time has elapsed since the heating operation was started, the supply of the heating source 31 to the absorption chiller 1 is stopped and the solution pump 19 is operated. Uniformization of the concentration of the absorption liquid S in the systems 10, 18, 30, and 38 in which the absorption liquid S can circulate, and the refrigerant in the systems 10, 18, 30, and 38 in which the absorption liquid S can be circulated by the refrigerant liquid mixing possible portion 70. The supply mechanism of the heating source 31, the solution pump 19, and the refrigerant liquid mixing possible unit 70 are controlled so as to perform a dilution operation for diluting the absorption liquid S by mixing at least one of the liquid Vf.

With this configuration, it is possible to reduce the energy consumption associated with continuing the low heating operation.

Further, the absorption chiller according to the third aspect of the present invention is absorbed in the absorption chiller 1 according to the first aspect or the second aspect of the present invention, for example, as shown with reference to FIG. The ambient environment temperature-related value grasping unit 55 for grasping the ambient environment temperature-related value related to the ambient temperature-related value of the chiller 1 is provided; the predetermined value is set to change according to the ambient temperature-related value. Has been done.

With this configuration, the predetermined value changes in consideration of the ambient temperature-related value related to the ambient temperature, which is the lower limit of the temperature of the absorbing liquid that can decrease after the supply of the heating source is stopped, and the ambient environment. The higher the temperature, the larger the predetermined value can be set, and the range in which the absorption liquid is not diluted can be expanded.

Further, the absorption chiller according to the fourth aspect of the present invention is, for example, as shown with reference to FIG. 1, the absorption type according to any one of the first to third aspects of the present invention. The refrigerator 1 includes absorption liquid concentration-related value grasping units 51, 52, and 60 for grasping the absorption liquid concentration-related values related to the concentration of the absorption liquid S; when the control device 60 stops the absorption chiller 1 In addition, when the absorption liquid concentration-related value grasped by the absorption liquid concentration-related value grasping units 51, 52, and 60 is equal to or less than the upper limit concentration of the absorption liquid S which does not require dilution, the low heating operation is performed. The absorption chiller 1 is stopped without performing the dilution operation for diluting the absorption liquid S.

With this configuration, the energy required to perform the low heating operation can be reduced.

Further, the absorption chiller according to the fifth aspect of the present invention is, for example, as shown with reference to FIG. 1, in the absorption chiller 1 according to the fourth aspect of the present invention, the absorption chiller 1 The ambient temperature-related value grasping unit 55 for grasping the ambient temperature-related value related to the ambient temperature is provided; the upper limit concentration at which dilution is not required is set to change according to the ambient temperature-related value.

With this configuration, the upper limit concentration that does not require dilution changes in consideration of the ambient temperature-related value related to the ambient temperature, which is the lower limit of the absorption liquid temperature that can decrease after the absorption chiller is stopped. The higher the ambient temperature, the higher the upper limit concentration that does not require dilution can be set, and the range in which the low heating operation is not performed and the absorption liquid is not diluted can be expanded.

Further, the absorption chiller according to the sixth aspect of the present invention is, for example, as shown with reference to FIG. 1, the absorption type according to any one of the first to fifth aspects of the present invention. In the chiller 1, the control device 60 determines the number of times of stopping the absorption cycle without mixing the refrigerant liquid Vf into the systems 10, 18, 30, and 38 in which the absorption liquid S can be circulated by the refrigerant liquid mixing possible unit 70. System 10 in which the absorption liquid S can circulate regardless of the value of the calculated concentration when the number of times of the above is reached or when the mixing of the absorption liquid S into the refrigerant V in the portion where the liquid Vf of the refrigerant is stored is detected. , 18, 30, 38 are controlled so that the refrigerant liquid Vf is mixed with the refrigerant liquid mixing unit 70. Here, stopping the absorption cycle without mixing the refrigerant liquid into the system in which the absorption liquid can circulate is typically stopping the absorption chiller without performing the dilution operation accompanied by the mixing of the refrigerant liquid. It is to be.

With this configuration, the refrigerant system can be purified when the absorbing liquid is mixed in the refrigerant system.

Further, the absorption chiller according to the seventh aspect of the present invention is, for example, as shown with reference to FIG. 1, the absorption type according to any one of the first to sixth aspects of the present invention. In the chiller 1, the control device 60 stops the absorption chiller 1 until a predetermined operation time or a predetermined number of operations elapses after injecting the absorption liquid S and the refrigerant V into the absorption chiller 1. At that time, regardless of the value of the calculated concentration, the concentration of the absorption liquid S in the systems 10, 18, 30, and 38 where the absorption liquid S can be circulated by the operation of the solution pump 19 is made uniform and absorbed by the refrigerant liquid mixing possible portion 70. The solution pump 19 and the refrigerant liquid mixing unit 70 are controlled so as to perform a dilution operation involving both mixing of the refrigerant liquid Vf into the systems 10, 18, 30, and 38 in which the liquid S can circulate.

With this configuration, a film can be appropriately formed on the surface of the constituent members of the absorption chiller.

In order to achieve the above object, the control program according to the eighth aspect of the present invention includes, for example, with reference to FIGS. 1 and 2, the absorption liquid S formed by supplying the heating source 31. A program that controls the absorption chiller 1 that cools or heats the temperature-controlled fluid C by an absorption cycle with the refrigerant V; the pressure of the regenerator 30 or the pressure of the regenerator 30 that constitutes the absorption chiller 1. In the absorption liquid concentration calculation step (S12) in which the concentration of the absorption liquid S is calculated based on the physical amount having a correlation with; the amount of heat input to the regenerator 30 is set to a predetermined amount when the absorption chiller 1 is stopped. The low heating operation step (S11) in which the reduced low heating operation is performed; and the absorption chiller 1 when the calculated concentration calculated in the absorption liquid concentration calculation step (S12) during the low heating operation is less than a predetermined value. The heating source supply stop step (S5) for stopping the supply of the heat source 31 of the above is provided.

With this configuration, the concentration of the absorbent is calculated based on the pressure of the regenerator or the physical quantity that correlates with the pressure of the regenerator while performing low heating operation, so that the saturated state in the regenerator is maintained and absorbed. The concentration of the liquid can be appropriately grasped, and the necessity of diluting the absorption liquid can be appropriately determined.

In order to achieve the above object, the control method of the absorption chiller according to the ninth aspect of the present invention is configured by supplying the heating source 31, for example, as shown with reference to FIGS. 1 and 2. It is a method of controlling the absorption chiller 1 that cools or heats the temperature-controlled fluid C by the absorption cycle of the absorption liquid S and the refrigerant V; the pressure of the regenerator 30 constituting the absorption chiller 1 or The absorption liquid concentration calculation step (S12), which calculates the concentration of the absorption fluid S based on the physical quantity correlating with the pressure of the regenerator 30, and the amount of heat input to the regenerator 30 when the absorption chiller 1 is stopped. In the low heating operation step (S11) in which the low heating operation is performed in which the amount of heat is reduced to a predetermined amount; absorption is performed when the calculated concentration calculated in the absorption liquid concentration calculation step (S12) during the low heating operation is less than a predetermined value. A heating source supply stop step (S5) for stopping the supply of the heat source 31 to the chiller 1 is provided.

With this configuration, the concentration of the absorbent is calculated based on the pressure of the regenerator or the physical quantity that correlates with the pressure of the regenerator while performing low heating operation, so that the saturated state in the regenerator is maintained and absorbed. The concentration of the liquid can be appropriately grasped, and the necessity of diluting the absorption liquid can be appropriately determined.

According to the present invention, the concentration of the absorbing liquid is calculated based on the pressure of the regenerator or the physical quantity (value detected by the regenerator pressure correlation value detection unit) that correlates with the pressure of the regenerator while performing the low heating operation. Therefore, the saturated state in the regenerator can be maintained, the concentration of the absorbing solution can be appropriately grasped, and the necessity of diluting the absorbing solution can be appropriately determined.

It is a schematic system diagram of the absorption chiller which concerns on embodiment of this invention. It is a flowchart explaining the first half part of the procedure at the time of stopping of the absorption chiller which concerns on embodiment of this invention. It is a flowchart explaining the latter half part of the procedure at the time of stopping of the absorption chiller which concerns on embodiment of this invention. It is a graph which illustrates the relationship between the crystal concentration of the absorption liquid and the upper limit concentration which does not need dilution with respect to the ambient temperature. It is a graph which shows the error between the calculated concentration and the actual absorption liquid concentration. It is a flowchart explaining the modified part of the procedure at the time of stopping of the absorption chiller which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, members that are the same as or correspond to each other are designated by the same or similar reference numerals, and duplicate description will be omitted.

In the present specification, the "absorption chiller" constitutes an absorption cycle by a regenerator, a condenser, an absorber, an evaporator, etc. by supplying a heating source to the regenerator, and cools or cools the fluid subject to temperature control. Absorption chiller, which is a general term for absorption heat source machines that perform heating, is a machine that supplies a heating source to a regenerator to form an absorption refrigeration cycle and supplies cold water (cooled fluid subject to temperature control). Absorption chiller-heater and heating source, which are machines that supply cold water (cooled temperature-controlled fluid) and / or hot water (heated temperature-controlled fluid) to the regenerator to form an absorption cycle. To the regenerator to form an absorption heat pump cycle, and by recovering heat from the heat source water with an evaporator, a machine that supplies hot water (heated fluid subject to temperature control) heated by the absorber and condenser. It includes an absorption heat pump. Hereinafter, the absorption chiller will be described as one form thereof, the absorption chiller.

First, the absorption chiller 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic system diagram of the absorption chiller 1. The absorption chiller 1 includes an absorber 10, an evaporator 20, a regenerator 30, a condenser 40, and a control device 60 as main components for performing the absorption chiller cycle. The absorption chiller 1 is a device that causes heat transfer by circulating the refrigerant V with respect to the absorption liquid S while changing the phase, and lowers the temperature of the cold water C, which is a fluid to be temperature-controlled. In the following description, the absorption liquor is referred to as "rare solution Sw", "concentrated solution Sa", etc., depending on the properties and the position on the absorption chilling cycle, in order to facilitate the distinction on the absorption chilling cycle. , When the properties are unquestioned, they are collectively referred to as "absorbent solution S". Further, in order to facilitate the distinction of the refrigerant on the absorption refrigeration cycle, "evaporator refrigerant vapor Ve", "regenerator refrigerant vapor Vg", and "refrigerant liquid Vf" are used according to the properties and the position on the absorption refrigeration cycle. However, when the properties are unquestioned, they are collectively referred to as "refrigerant V". In this embodiment, the absorbing liquid S and LiBr solution is used as (a mixture of absorbent and refrigerant) is water (H 2 _O) is used as the refrigerant V, other refrigerants not limited thereto , May be used in combination with a solution (absorbent).

The absorber 10 is a device that absorbs the evaporator refrigerant vapor Ve generated in the evaporator 20 with the concentrated solution Sa. The absorber 10 has a cooling pipe 11 as a cooling water flow path for flowing the cooling water D and a concentrated solution spraying nozzle 12 for spraying the concentrated solution Sa toward the outer surface of the cooling pipe 11 inside the absorber can body 17. Have. The concentrated solution spraying nozzle 12 is arranged above the cooling pipe 11 so that the sprayed concentrated solution Sa falls on the cooling pipe 11. In the absorber 10, the sprayed concentrated solution Sa absorbs the evaporator refrigerant vapor Ve, so that the rare solution Sw whose concentration has decreased is stored in the lower part of the absorber can body 17, and the concentrated solution Sa is the evaporator refrigerant vapor. The cooling water D is configured to take away the absorbed heat generated when the Ve is absorbed.

The evaporator 20 is a device that cools the cold water C by evaporating the refrigerant liquid Vf with the heat of the cold water C to generate the evaporator refrigerant vapor Ve. The evaporator 20 has an evaporator pipe 21 as a chilled water flow path through which the chilled water C flows, and a refrigerant liquid spray nozzle 22 for spraying the refrigerant liquid Vf toward the outer surface of the evaporator pipe 21 inside the evaporator can body 27. doing. The refrigerant liquid spray nozzle 22 is arranged above the evaporation pipe 21 so that the sprayed refrigerant liquid Vf falls on the evaporation pipe 21. The evaporator 20 uses a refrigerant liquid pipe 28 that guides the refrigerant liquid Vf stored in the lower part of the evaporator can body 27 to the refrigerant liquid spray nozzle 22 and the refrigerant liquid Vf in the refrigerant liquid pipe 28 to the refrigerant liquid spray nozzle 22. It has a refrigerant pump 29 to send. The evaporator 20 cools the cold water C by taking the heat of vaporization for the refrigerant liquid Vf sprayed on the outer surface of the evaporation pipe 21 to become the evaporator refrigerant vapor Ve from the cold water C flowing in the evaporation pipe 21. However, of the sprayed refrigerant liquid Vf, the non-evaporated refrigerant liquid Vf is configured to be stored in the lower part of the evaporator can body 27.

In the present embodiment, the absorber 10 and the evaporator 20 are arranged adjacent to each other, and the upper part of the absorber can body 17 and the upper part of the evaporator can body 27 communicate with each other. With such a configuration, the evaporator refrigerant vapor Ve generated inside the evaporator can body 27 can be guided to the inside of the absorber can body 17. A cooling water inlet pipe 11a for introducing the cooling water D is connected to one end of the cooling pipe 11. A cooling water connecting pipe 58 is connected to the other end of the cooling pipe 11. A cooling water outflow pipe 98 outside the absorption chiller 1 is connected to the cooling water inlet pipe 11a. The cooling water outflow pipe 98 is connected to a cooling tower (not shown) outside the absorption chiller 1. A cooling water pump 91 outside the absorption chiller 1 is arranged in the cooling water outflow pipe 98. The absorption chiller 1 is configured such that the cooling water D flows in the cooling pipe 11 by the operation of the cooling water pump 91. A chilled water inlet pipe 21a for introducing chilled water C is connected to one end of the evaporation pipe 21, and a chilled water outlet pipe 21b for letting out chilled water C is connected to the other end. A chilled water return pipe 95 outside the absorption chiller 1 is connected to the chilled water inlet pipe 21a. A chilled water pump 92 outside the absorption chiller 1 is arranged in the chilled water return pipe 95. The absorption chiller 1 is configured such that the chilled water C flows in the evaporation pipe 21 by the operation of the chilled water pump 92. A chilled water outflow pipe 96 outside the absorption chiller 1 is connected to the chilled water outlet pipe 21b.

The regenerator 30 is a device that introduces a dilute solution Sw and heats it to release the refrigerant V in the dilute solution Sw to generate a concentrated solution Sa. In the regenerator 30, the refrigerant V separated from the dilute solution Sw is in a vapor state, and the vapor of this refrigerant V is referred to as the regenerator refrigerant vapor Vg. The regenerator 30 has a heating unit 31 for heating the dilute solution Sw, and a regenerator can body 37 for storing the introduced absorption liquid S. The heating unit 31 is arranged inside the regenerator can body 37 and functions as a heating source. The heating unit 31 is typically configured so that the absorption liquid S can be heated by the combustion heat of the burner and the heat of steam, hot water, or the like introduced from the outside. As the regenerator 30, a once-through type regenerator, a smoke tube type regenerator, a liquid tube type regenerator, or the like can be used.

The condenser 40 is a device that introduces the regenerator refrigerant vapor Vg evaporated from the dilute solution Sw in the regenerator 30, cools and condenses it, and generates the refrigerant liquid Vf to be sent to the evaporator 20. The condenser 40 has a condenser pipe 41, which is a member forming a flow path of the cooling water D, inside the condenser can body 47. The other end of the cooling water connecting pipe 58, one end of which is connected to the cooling pipe 11, is connected to one end of the condensing pipe 41. A cooling water outlet pipe 41b for flowing out the cooling water D is connected to the other end of the condensing pipe 41. A cooling water return pipe 99 outside the absorption chiller 1 is connected to the cooling water outlet pipe 41b. The cooling water return pipe 99 is connected to a cooling tower (not shown) outside the absorption chiller 1. With such a configuration, the cooling water D flowing through the cooling water return pipe 99 is cooled by a cooling tower (not shown) and supplied to the cooling water outgoing pipe 98.

The condenser can body 47 is arranged close to the regenerator can body 37. In the present embodiment, the upper part of the regenerator can body 37 and the upper part of the condenser can body 47 communicate with each other via the regenerator refrigerant vapor flow path 35. The condenser 40 introduces the regenerator refrigerant vapor Vg from the regenerator 30 via the regenerator refrigerant vapor flow path 35, causes the cooling water D flowing through the condenser pipe 41 to take away the heat of the regenerator refrigerant vapor Vg, and regenerates. It is configured to condense the refrigerant vapor Vg into the refrigerant liquid Vf. In the present embodiment, the condenser can body 47 and the regenerator can body 37 are arranged above the evaporator can body 27 and the absorber can body 17. The portion of the condenser can body 47 in which the refrigerant liquid Vf is stored (typically the bottom or bottom of the condenser can body 47) and the evaporator can body 27 are connected by a condensed refrigerant liquid pipe 48 to condense. It is configured so that the refrigerant liquid Vf in the vessel body 47 can be guided into the evaporator can body 27 by the difference between the position head and the internal pressures of the two.

The portion of the absorber can body 17 where the dilute solution Sw is stored (typically the bottom or bottom of the absorber can body 17) and the regenerator can body 37 are connected by a dilute solution tube 18. A solution pump 19 is arranged in the dilute solution tube 18. The absorption chiller 1 is configured so that the dilute solution Sw of the absorber can body 17 can be conveyed into the regenerator can body 37 by the solution pump 19. In the regenerator can body 37, as the introduced dilute solution Sw moves from the inlet to the outlet, the refrigerant V is separated from the dilute solution Sw and the concentration increases.

The portion of the regenerator can body 37 from which the concentrated solution Sa flows out and the concentrated solution spray nozzle 12 of the absorber 10 are connected by a concentrated solution pipe 38. In the absorption chiller 1, the dilute solution Sw is conveyed to the regenerator can body 37 by the solution pump 19, and the concentrated solution Sa generated by the refrigerant V being separated from the regenerator can body 37 passes through the concentrated solution tube 38. It is configured to be introduced into the concentrated solution spraying nozzle 12. That is, the solution pump 19 can circulate the absorbing liquid S between the absorber 10 and the regenerator 30. The concentrated solution tube 38 is provided with a concentrated solution thermometer 51 that detects the temperature of the concentrated solution Sa at the outlet of the regenerator 30. The regenerator can body 37 is provided with a refrigerant thermometer 52 that detects the temperature of the refrigerant V inside. The refrigerant thermometer 52 detects the dew point temperature of the refrigerant V in the regenerator 30 during the operation of the absorption chiller 1. Since the dew point temperature of the refrigerant V in the regenerator 30 is a physical quantity having a correlation with the pressure in the regenerator 30, the refrigerant thermometer 52 corresponds to the regenerator pressure correlation value detection unit. The refrigerant thermometer 52 may be provided in the regenerator refrigerant vapor flow path 35. A solution heat exchanger 81 for exchanging heat between the dilute solution Sw flowing through the dilute solution tube 18 and the concentrated solution Sa flowing through the concentrated solution tube 38 is inserted and arranged in the dilute solution tube 18 and the concentrated solution tube 38. Has been done.

The portion of the condenser can body 47 in which the refrigerant liquid Vf is stored (typically the bottom or bottom of the condenser can body 47) and the concentrated solution pipe 38 form a concentrated solution of the refrigerant liquid Vf in the condenser can body 47. It is connected by a refrigerant solution mixing pipe 71 leading to the pipe 38. The refrigerant liquid mixing pipe 71 is provided with a refrigerant liquid mixing valve 72 that opens and closes the flow path. In the present embodiment, the refrigerant liquid mixing pipe 71 and the refrigerant liquid mixing valve 72 constitute the refrigerant liquid mixing possible portion 70. The refrigerant liquid mixing possible portion 70 mixes the refrigerant liquid Vf when the refrigerant liquid mixing valve 72 is opened into the concentrated solution pipe 38, and the refrigerant liquid Vf when the refrigerant liquid mixing valve 72 is closed is mixed into the concentrated solution pipe 38. It is configured so that it can be switched between a state in which the refrigerant is not mixed. Further, an ambient thermometer 55 for detecting the air temperature is provided in the vicinity of the regenerator 30 outside the regenerator 30. The air temperature outside the regenerator 30 is a temperature that correlates with the surrounding environment of the absorption chiller 1, and corresponds to a value related to the ambient environment temperature. The ambient thermometer 55 corresponds to an ambient temperature-related value grasping unit.

The control device 60 is a device that controls the operation of the absorption chiller 1. The control device 60 is electrically connected to the heating unit 31 by wire or wirelessly, and is configured to be able to adjust the amount of heat input to the heating unit 31. Further, the control device 60 is electrically connected to the solution pump 19, the refrigerant pump 29, the cooling water pump 91, and the chilled water pump 92, respectively, by wire or wirelessly, so that the start and stop of these can be controlled. It is configured. Further, the control device 60 is electrically connected to the concentrated solution thermometer 51, the refrigerant thermometer 52, and the ambient thermometer 55, respectively, by wire or wirelessly, and can receive the detected temperature as a signal. It is configured as follows. Further, the control device 60 determines the concentration of the absorbing liquid S flowing through the concentrated solution tube 38 from the temperature detected by the concentrated solution thermometer 51 and the temperature detected by the refrigerant thermometer 52 (saturation temperature of the refrigerant V). It is configured so that it can be calculated. The concentration of the absorbing liquid S calculated by the control device 60 is referred to as "calculated concentration". The calculated concentration is an aspect of a value related to the concentration of the absorbing liquid S, and also serves as a value related to the concentration of the absorbing liquid. Further, in the present embodiment, the temperature detected by the concentrated solution thermometer 51, the temperature detected by the refrigerant thermometer 52, and the control device 60 can cooperate to grasp the absorption liquid concentration-related value. The concentrated solution thermometer 51, the refrigerant thermometer 52, and the control device 60 constitute an absorption liquid concentration-related value grasping unit. Further, the control device 60 is electrically connected to the refrigerant liquid mixing valve 72 by wire or wirelessly, and is configured to be able to switch the opening and closing of the refrigerant liquid mixing valve 72. Further, the control device 60 is configured to be able to control the absorption chiller 1 as described in the operation of the absorption chiller 1 described later. The control of the absorption chiller 1 described later is stored in the control device 60 as a sequence program.

Subsequently, the operation of the absorption chiller 1 will be described with reference to FIG. First, the operation of the absorption chiller 1 during steady operation will be described. During steady operation of the absorption chiller 1, the refrigerant liquid mixing valve 72 is closed by a command from the control device 60, and the solution pump 19, the refrigerant pump 29, the cooling water pump 91, and the chilled water pump 92 operate respectively. ing. Looking at the cycle on the refrigerant V side, the regenerator refrigerant vapor Vg introduced from the regenerator 30 into the condenser 40 via the regenerator refrigerant vapor flow path 35 is cooled by the cooling water D flowing through the condenser pipe 41 and condensed. Then, it becomes the refrigerant liquid Vf and is stored in the lower part of the condenser can body 47. The cooling water D obtained by cooling the regenerator refrigerant vapor Vg rises in temperature, flows out of the cooling water return pipe 99, and is supplied to a cooling tower (not shown). The refrigerant liquid Vf in the condenser can body 47 is introduced into the evaporator can body 27 via the condensed refrigerant liquid pipe 48.

The refrigerant liquid Vf introduced from the condenser can body 47 into the evaporator can body 27 is mixed with the refrigerant liquid Vf that was sprayed from the refrigerant liquid spray nozzle 22 and did not evaporate, and is stored in the lower part of the evaporator can body 27. To. The refrigerant liquid Vf in the evaporator can body 27 flows through the refrigerant liquid pipe 28 by the refrigerant pump 29 and reaches the refrigerant liquid spray nozzle 22. The refrigerant liquid Vf that has reached the refrigerant liquid spray nozzle 22 is sprayed toward the evaporation pipe 21, and the heat of the cold water C flowing through the evaporation pipe 21 is obtained and a part of the refrigerant liquid Vf evaporates to become the evaporator refrigerant steam Ve, which becomes an absorber can. It is introduced into the body 17. The temperature of the cold water C, which has been deprived of heat by the sprayed refrigerant liquid Vf, drops and flows out from the cold water outflow pipe 96, and is supplied to a place where the cold water C is used, such as an air conditioner. The refrigerant liquid Vf sprayed from the refrigerant liquid spray nozzle 22 and not evaporated is mixed with the refrigerant liquid Vf introduced from the condenser can body 47 and stored in the lower part of the evaporator can body 27.

Next, looking at the cycle on the solution S side of the absorption chiller 1, the dilute solution Sw in the absorber can body 17 flowed through the dilute solution tube 18 by the solution pump 19, and the temperature rose in the solution heat exchanger 81. Later, it is introduced into the regenerator can body 37. The dilute solution Sw introduced into the regenerator can body 37 is heated by the heating unit 31, and the refrigerant V is separated to become a concentrated solution Sa. On the other hand, the refrigerant V separated from the dilute solution Sw is sent as the regenerator refrigerant vapor Vg into the condenser can body 47 via the regenerator refrigerant vapor flow path 35. The concentrated solution Sa generated in the regenerator can body 37 flows through the concentrated solution tube 38, exchanges heat with the dilute solution Sw in the solution heat exchanger 81, lowers the temperature, and then reaches the concentrated solution spray nozzle 12.

The concentrated solution Sa that has reached the concentrated solution spraying nozzle 12 is sprayed toward the cooling pipe 11, absorbs the evaporator refrigerant vapor Ve introduced from the evaporator 20, and the concentration decreases to become a dilute solution Sw. Endothermic heat is generated when the concentrated solution Sa absorbs the evaporator refrigerant vapor Ve in the absorber can body 17. The generated absorbed heat is removed by the cooling water D which is introduced from the cooling water outward pipe 98 and flows through the cooling pipe 11. The cooling water D flowing through the cooling pipe 11 takes away the absorbed heat, rises in temperature, flows out to the cooling water connecting pipe 58, and is supplied to the condenser pipe 41 of the condenser 40. The dilute solution Sw generated in the absorber can body 17 is stored in the absorber can body 17.

The absorption chiller 1 performing the steady operation as described above needs to operate the absorption chiller 1 with the load of the air conditioner or the like in which the cold heat of the cold water C is used reduced (including the elimination of the load). When there is no more, the heat input to the heating unit 31 is stopped, and the absorption chiller 1 is stopped. Generally, when the absorption chiller is stopped, a dilution operation is often performed in order to prevent crystallization of the absorption liquid when the temperature drops. In the dilution operation, usually, an appropriate amount of refrigerant is mixed with the absorption liquid and circulated to homogenize the absorption liquid in the absorption chiller at a concentration that does not crystallize. Then, when the absorption chiller in which the absorption liquid is diluted is started due to an increase in load or the like, the absorption liquid is heated to cause a concentration difference in the absorption liquid. In the absorption chiller, cold water having a desired temperature can be obtained after a predetermined concentration difference occurs in the absorption liquid. As described above, in the absorption chiller, energy that does not contribute to the production of cold water is consumed from the start of the dilution operation to the steady operation through the restart. This energy consumption is necessary to avoid crystallization of the absorption liquor, but it is useless if the absorption liquor does not crystallize between the time the absorption chiller is stopped and the time it is restarted. .. Therefore, in the absorption chiller 1 according to the present embodiment, the following control is performed in order to avoid such waste.

2 and 3 are flowcharts for explaining the procedure when the absorption chiller 1 is stopped, FIG. 2 shows the first half portion, and FIG. 3 shows the second half portion. FIG. 2 and FIG. 3 together show one stop procedure. Hereinafter, the control when the absorption chiller 1 is stopped will be described mainly with reference to FIGS. 2 and 3, but when the configuration of the absorption chiller 1 is referred to in the description, FIG. 1 shall be referred to as appropriate. To do. During the steady operation of the absorption chiller 1, the control device 60 controls the operation of each device constituting the absorption chiller 1, and a stop command is given from a device (not shown) that uses cold water C such as an air conditioner. I am trying to receive it. In other words, the control device 60 determines whether or not there is a stop command (S1). If there is no stop command, the process returns to the step (S1) of determining whether or not there is a stop command again.

In the step (S1) of determining whether or not there was a stop command, when a stop command was given, the control device 60 calculated based on the temperature detected by the concentrated solution thermometer 51 and the temperature detected by the refrigerant thermometer 52. It is determined whether or not the concentration of the absorbing solution S (concentrated solution Sa) is equal to or less than the upper limit concentration at which dilution is not required (S3). Here, the upper limit concentration that does not require dilution is a concentration at which crystals of the absorption liquid S do not form even if the temperature drops to the temperature of the ambient environment of the absorption chiller 1 (hereinafter referred to as "ambient environment temperature") as it is without performing the dilution operation. Is the upper limit of. In the dilution operation, the concentration of the absorbing liquid S is made uniform by operating the solution pump 19 (hereinafter referred to as “solution stirring”), the refrigerant liquid mixing valve 72 is opened for a predetermined time, and the refrigerant liquid in the condenser 40 is opened. There are two methods of flowing a predetermined amount of Vf into the concentrated solution tube 38 (hereinafter referred to as “refrigerant transfer”), and the upper limit concentration at which dilution is not required is the upper limit of the concentration at which dilution operation is unnecessary for both. In this embodiment, the upper limit concentration that does not require dilution is variable according to the temperature detected by the ambient thermometer 55. The higher the concentration of the absorbent S, the higher the temperature, and the lower the concentration, the lower the temperature. The absorption liquid S, which has a relatively high temperature during steady operation of the absorption chiller 1, approaches the ambient temperature when the absorption chiller 1 is stopped, and does not fall below the ambient temperature. That is, since the closeness of the concentration of the absorbing liquid S to the crystallizing concentration changes according to the ambient environment temperature, in the present embodiment, it depends on the ambient environment temperature (the temperature detected by the ambient thermometer 55). The upper limit concentration that does not require dilution is variable.

The graph of FIG. 4 shows an example of the relationship between the crystal concentration of the absorbent S and the upper limit concentration that does not require dilution with respect to the ambient temperature (sometimes simply referred to as “ambient temperature”). In the graph of FIG. 4, the solid line Ls shows the relationship between the ambient temperature and the crystal concentration of the absorbent S. In the present embodiment, a value having a predetermined margin with respect to the crystal concentration of the absorbent S is defined as the upper limit concentration that does not require dilution, and is indicated by the broken line Lb in the graph of FIG. For example, when the ambient temperature detected by the ambient temperature gauge 55 is 15 ° C., where the crystal concentration of the absorbing solution S is 60%, the concentration (for example, ambient) in which a margin is added to the crystal concentration at the ambient temperature (15 ° C.). The concentration of the absorbing liquid at a temperature of 15 ° C. (59%) is set as the upper limit concentration that does not require dilution, and the diagram obtained for each ambient temperature is shown by the broken line Lb. The predetermined margin may be variable, such as the alternate long and short dash line Ld, which increases as the ambient temperature increases and decreases as the ambient temperature decreases.

Mainly returning to FIGS. 2 and 3, the description of the procedure when the absorption chiller 1 is stopped will be continued. In the step (S3) of determining whether or not the concentration of the absorbing liquid S is equal to or less than the upper limit concentration requiring dilution, the control device 60 stops heating in the heating unit 31 when the concentration is equal to or less than the upper limit concentration requiring dilution (S5). Next, the control device 60 determines whether or not the number of times N for stopping the non-mixing of the refrigerant is equal to or greater than a predetermined number (S6). Here, the number of times N for stopping the non-mixing of the refrigerant is such that after the absorption chiller 1 is stopped after the last dilution operation involving the mixing of the refrigerant liquid Vf in the absorbing liquid S, the refrigerant liquid Vf in the absorbing liquid S is stopped. This is the number of times the absorption refrigeration cycle was stopped without mixing. In the absorption chiller 1, the absorption liquid S may be mixed into the system of the refrigerant V due to the scattering of the absorption liquid S or the accompanying droplets of the absorption liquid S in the regenerator refrigerant vapor Vg during operation. .. Mixing the absorbing liquid S into the system of the refrigerant V may cause a deterioration in the cooling performance of the cold water C in the absorption chiller 1. Therefore, when the refrigerant liquid Vf is mixed into the system of the absorption liquid S, when the absorption liquid S is mixed in the system of the refrigerant V, the refrigerant liquid Vf containing the absorption liquid S is introduced into the system of the absorption liquid S. It is possible to purify the system of the refrigerant V by performing an absorption refrigeration cycle later to evaporate the refrigerant V and return it to the system of the refrigerant V. Therefore, in the absorption chiller 1, the refrigerant liquid Vf is mixed into the absorption liquid S system at least every time the refrigerant non-mixing stop count N reaches a predetermined number, and the concentration of the absorption liquid S in the refrigerant V system increases. It is supposed to suppress doing.

In the step (S6) of determining whether or not the number of times N for stopping the non-mixing of the refrigerant is not more than the predetermined number of times, if the number of times is not more than the predetermined number (less than the predetermined number of times), the control device 60 is not mixed with the refrigerant at that time. 1 is added to the number of stops N (S7), and the absorption chiller 1 is stopped on standby (S9). The standby stop of the absorption chiller 1 is to put the absorption chiller 1 in a stopped state without performing the dilution operation of the absorption chiller 1, and in a state of waiting so that the steady operation can be started as needed. is there.

In the step (S3) of determining whether or not the concentration of the absorption liquid S is not less than or equal to the upper limit concentration requiring dilution, the control device 60 is in a state of low heating operation of the absorption chiller 1 when the concentration is not less than or lower than the upper limit concentration requiring dilution. (S11). The low heating operation is an operation in which the amount of heat input to the regenerator 30 by the heating unit 31 is reduced to a predetermined amount while continuing the operation of the solution pump 19 in a state where the refrigerant liquid Vf is not mixed in the system of the absorbing liquid S. It is in a state. The predetermined amount of heat is typically the amount of heat reduced as much as possible within the range in which the saturated state in the regenerator 30 can be maintained. By doing so, it is possible to suppress the consumption of heat energy while maintaining the saturated state in the regenerator 30. Here, the low heating operation is performed because if the heat input to the regenerator 30 is completely stopped, the saturated state in the regenerator 30 cannot be maintained and the difference between the calculated concentration and the actual concentration becomes large. Because it will end up. After starting the low heating operation (S11), the control device 60 calculates the calculated concentration based on the temperature detected by the concentrated solution thermometer 51 and the temperature detected by the refrigerant thermometer 52 (S12). The step of calculating the calculated concentration (S12) may be performed in parallel with the step of starting the low heating operation (S11), or may be performed before the step of starting the low heating operation (S11). That is, the step (S12) of calculating the calculated concentration is performed at least when the low heating operation is performed (at least when the heating unit 31 has a heat input amount capable of maintaining the saturated state in the regenerator 30).

Next, the control device 60 determines whether or not the calculated density is less than a predetermined value (S13). The predetermined value is a value obtained by adding a margin to the upper limit of the concentration that does not crystallize even if the temperature of the absorbing liquid S drops to the ambient temperature. In the present embodiment, the predetermined value is variable according to the ambient temperature, as in the case of the above-mentioned upper limit concentration that does not require dilution (see FIG. 4). Here, if the calculated concentration deviates significantly from the actual concentration of the absorption liquid S, it will affect the determination of stopping the absorption chiller 1. Therefore, the calculated concentration and the actual absorption liquid S are described below. The difference from the concentration will be described.

FIG. 5 shows the difference between the calculated concentration and the actual concentration of the absorbent S. In FIG. 5, the horizontal axis represents the dilution time, and the vertical axis represents the concentration of the absorbent S of the regenerator 30. In FIG. 5, the solid line Cc represents the calculated concentration, and the broken line Ca represents the actual concentration of the absorbent S. As shown in FIG. 5, the two showing the same value at the start of the dilution operation deviate from each other so that the calculated concentration becomes lower than the actual value with the passage of time, but for a certain time (in the example shown in FIG. 5). After 10 minutes), the dissociation width will not widen. This deviation is within the range of an error in practical use for determining the necessity of dilution operation, and a predetermined value may be determined by considering this error as a margin.

Mainly returning to FIGS. 2 and 3, in the step (S13) of determining whether or not the calculated concentration is less than the predetermined value, if it is less than the predetermined value, the step of stopping the heating in the heating unit 31 (S5). ). On the other hand, if it is not less than a predetermined value, the control device 60 determines whether or not a predetermined time has elapsed since the start of the low heating operation (S14). The predetermined time is a time that allows waiting for the calculated concentration to become less than a predetermined value while considering the energy consumption related to heat generation by the heating unit 31, and may be, for example, about 10 minutes to 15 minutes. In the step (S14) of determining whether or not the predetermined time has elapsed, if the predetermined time has not elapsed, the process returns to the step of calculating the calculated concentration (S12).

In the step (S14) of determining whether or not the predetermined time has elapsed, when the predetermined time has elapsed, the control device 60 stops the heating in the heating unit 31 (S15). Next, the control device 60 determines whether or not the number of times N for stopping the non-mixing of the refrigerant is equal to or greater than a predetermined number (S16). This step (S16) has the same contents as the above-mentioned step (S6), but since the subsequent steps are different from the above-mentioned step (S6), it is defined as an independent step. In the step (S16) of determining whether or not the number of times N of refrigerant non-mixed stops is equal to or greater than a predetermined number of times, the control device 60 sets the number of times N of non-mixed refrigerant stopped N to 0 (S18) and the refrigerant is not mixed. A dilution operation accompanied by transfer is performed (S19), and the absorption chiller 1 is stopped (S29). In the step (S6) of determining whether or not the above-mentioned number of non-refrigerant stop counts N is equal to or greater than the predetermined number of times, the process proceeds to the step (S18) of setting the number of non-refrigerant stop counts N to 0. After that, follow the above flow.

In the step (S16) of determining whether or not the number of times N for stopping the non-mixing of the refrigerant is equal to or more than a predetermined number of times, if it is not more than or equal to the predetermined number of times (less than the predetermined number of times), the control device 60 performs a dilution operation (S21). .. In this dilution operation (S21), either one or both of solution stirring and refrigerant transfer are performed. By stirring the solution while the heat input to the heating unit 31 is stopped, the concentration difference between the concentrated solution Sa and the dilute solution Sw becomes small, the concentration of the concentrated solution Sa decreases, and the absorbing solution S crystallizes. Can be avoided. By transferring the refrigerant, it is possible to prevent the concentrated solution Sa in the concentrated solution pipe 38 from being diluted with the refrigerant liquid Vf to reduce the concentration and crystallize the absorbing liquid S. Further, by transferring the refrigerant, the system of the refrigerant V can be purified as described above.

After the dilution operation (S21) is performed, the control device 60 determines whether or not the refrigerant transfer has been performed (whether or not the refrigerant liquid Vf is mixed in the absorption liquid S) (S23). Whether or not the refrigerant transfer has been carried out can be determined by whether or not the refrigerant liquid mixing valve 72 is opened for a predetermined time. When the refrigerant transfer is not performed, 1 is added to the number of times N of refrigerant non-mixing stops at that time (S27). When the refrigerant is transferred, the number of non-refrigerant stop counts N is set to 0 (S28). When 1 is added to the refrigerant non-mixed stop count N (S27) or when the refrigerant non-mixed stop count N is set to 0 (S28), the control device 60 proceeds to the step of stopping the absorption chiller 1 (S29).

Subsequently, the procedure for restarting the absorption chiller 1 from the state in which the absorption chiller 1 is on standby (S9) or stopped (S29) will be described. As described above, the standby stop (S9) is a state in which the absorption chiller 1 is stopped without performing the dilution operation, and the stop (29) is a state in which the absorption chiller 1 is stopped after performing the dilution operation. It is in a state of being. In the state of standby stop (S9), the control device 60 determines whether or not there is a restart command (S31). If there is no restart command, the process returns to the step (S31) of determining whether or not there is a restart command. On the other hand, when there is a restart command, the control device 60 restarts the absorption chiller 1 (S32). To restart the absorption chiller 1, after confirming that the refrigerant liquid mixing valve 72 is closed, the solution pump 19, the refrigerant pump 29, the cooling water pump 91, and the chilled water pump 92 are started to heat the heating unit 31. It is done by throwing it in. In the restart (S32) here, since the absorption chiller 1 did not perform the dilution operation and was stopped on standby, a predetermined concentration was formed between the concentrated solution Sa and the dilute solution Sw in the absorption chiller 1. There is a difference. The predetermined concentration difference is a concentration difference capable of forming an absorption refrigeration cycle between the absorption liquid S capable of producing cold water C at a desired temperature and the refrigerant V. If there is a predetermined concentration difference between the concentrated solution Sa and the dilute solution Sw when the restart (S32) is performed, a predetermined concentration difference is found between the concentrated solution Sa and the dilute solution Sw after the restart (S32). It is possible to shift to steady operation without performing start operation with a difference in concentration, and not only can the time required from the start of restart to steady operation be significantly shortened, but also it is required at start operation. Energy consumption can be reduced.

On the other hand, in the state where the absorption chiller 1 is stopped (S29) after the dilution operation is performed, the control device 60 determines whether or not there is a restart command (S33). If there is no restart command, the process returns to the step (S33) of determining whether or not there is a restart command again. When there is a restart command, the control device 60 restarts the absorption chiller 1 (S35). In the restart here, as in the restart step (S32) described above, after confirming that the refrigerant liquid mixing valve 72 is closed, the solution pump 19, the refrigerant pump 29, the cooling water pump 91, and the chilled water pump 92 are restarted. This is performed by starting and applying heat to the heating unit 31. At this time, since the absorption chiller 1 was stopped due to the dilution of the absorption liquor S, the concentration distribution of the absorption chiller S was not in a state where the desired capacity of the absorption chiller 1 could be exhibited. A start-up operation is performed in which a predetermined concentration difference is provided between the dilute solution and Sw (S37). During the start-up operation, the cold water C is flowing by starting the cold water pump 92, but since the cold water C is not cooled to a desired temperature, the cold water C is not supplied to the load of the air conditioner or the like. When the start-up operation is performed, a concentration difference gradually increases between the concentrated solution Sa and the dilute solution Sw, and eventually a steady operation state (an operation state capable of exerting a desired refrigerating capacity) is reached. It takes a considerable amount of time from the start of restarting the absorption chiller 1 to the state of steady operation.

By the way, immediately after the absorption chiller 1 is installed at the installation location, or when the absorption chiller S and the refrigerant V are removed from the absorption chiller 1 for maintenance or the like, the absorption chiller S and the refrigerant V are contained in the absorption chiller 1. May not be included. In this case, the absorption liquid S and the refrigerant V are injected into the absorption chiller 1 before the absorption chiller 1 is operated. At this time, in order to form a film on the surface of the internal constituent members of the absorption chiller 1, it is advisable to mix an appropriate amount of molybdenum into the absorption liquid S. The lower the concentration of the absorption liquid S, the faster the dissolution of molybdenum in the absorption liquid S. Therefore, from the injection of the absorption liquid S and the refrigerant V into the absorption chiller 1 until a predetermined operation time elapses or a predetermined number of operations elapses (hereinafter, both are collectively "until the predetermined conditions are satisfied". When there is a command to stop the absorption chiller 1, both solution stirring and refrigerant transfer are performed regardless of whether or not the concentration is below the upper limit concentration that does not require dilution and whether or not the calculated concentration is less than a predetermined value. It is advisable to carry out the accompanying dilution operation. The number of operations is the number of times the absorption cycle is operated from the state in which the absorption cycle of the absorption liquid S and the refrigerant V is stopped. When the dilution operation involving both solution stirring and refrigerant transfer is performed until the predetermined conditions are satisfied, as shown in FIG. 6, in the flowcharts of FIGS. 2 and 3, it is determined whether or not there is a stop command ( After the stop command is given in S1), it is determined whether or not the predetermined conditions are satisfied (S2), and if the predetermined conditions are not satisfied, the process proceeds to the step of performing the dilution operation (S21), and the predetermined conditions are satisfied. If is satisfied, it is advisable to proceed to the step (S3) of determining whether or not the concentration of the absorbing solution S is equal to or less than the upper limit concentration requiring dilution.

The flow of the absorption chiller 1 described above (procedure at the time of stopping) is typically executed by a control program installed in the control device 60. Therefore, it is possible to easily change the set value in the flow, add or omit a part of the process, update, etc., and easily provide (distribute) the control program via a wired or wireless network. it can.

As described above, according to the absorption refrigerator 1 according to the present embodiment, when the stop command is received, the concentration of the absorption liquid S is equal to or less than the upper limit concentration requiring dilution, or the concentration of the absorption liquid S is high. Even if the concentration is not less than the upper limit concentration that does not require dilution, if the calculated concentration is less than the specified value during low heating operation and the number of times N of refrigerant non-mixing stops is not more than the specified number, it is immediately absorbed. If the standby stop is performed without diluting the liquid S and then a restart command is received, it is possible to shift to the steady operation without performing the start operation. Therefore, the absorption liquid S is diluted and the liquid S is diluted. The energy required for the start-up operation can be reduced, and the time from the restart to the steady operation can be shortened. Further, since the calculated concentration is calculated at least when the low heating operation is performed, the concentration of the absorbing liquid S can be appropriately grasped.

In the above description, it is assumed that the regenerator pressure correlation value detection unit is a refrigerant thermometer 52 that detects the dew point temperature of the refrigerant V in the regenerator 30, which is a physical quantity that correlates with the pressure in the regenerator 30. It may be a pressure gauge or the like that detects the pressure in the regenerator 30. Further, the calculated concentration is calculated from the temperature detected by the concentrated solution thermometer 51 and the temperature detected by the refrigerant thermometer 52, but the pressure in the regenerator 30 is detected and the temperature in the regenerator 30 is detected. The temperature of the absorption liquid S may be detected, and the concentration may be calculated from the detected pressure and temperature.

In the above description, it is assumed that the absorption liquid concentration-related value also serves as the calculated concentration. For example, a concentrated solution concentration meter for detecting the concentration of the concentrated solution Sa at the outlet of the regenerator 30 is provided in the concentrated solution tube 38 to provide a concentrated solution. It may be the concentration of the absorption solution S detected by the densitometer, or a physical amount related to the concentration of the absorption solution S (temperature / density of the absorption solution S at the outlet of the regenerator 30, pressure / dew point inside the regenerator 30). Temperature, etc.), concentration of dilute solution Sw, level of refrigerant V, level of absorption liquid S in absorber 10, refrigerating load factor of absorption refrigerator 1, temperature of cooling water D, inverter of solution pump 19 or refrigerant pump 29, etc. It may be a single unit of the frequency, the amount of heating in the heating unit 31 (including the opening degree of the heating amount adjusting valve), or a combination of a plurality of these. However, from the viewpoint of reducing the cost of the device configuration, it is preferable to avoid the use of the concentrated solution concentration meter.

In the above explanation, the value related to the ambient temperature is the atmospheric temperature in the vicinity of the regenerator 30, but in addition to this, physical quantities related to the ambient temperature such as the temperature of the outermost housing of the absorption chiller 1 are used. There may be.

In the above explanation, it is assumed that the upper limit concentration without dilution and the predetermined value are variable according to the ambient temperature, but either one or both of the upper limit concentration without dilution and the predetermined value is not related to the ambient temperature (safety). It may be a fixed value (set lower by looking at). In this way, control can be simplified.

In the above description, it is determined whether or not the dilution accompanied by the refrigerant transfer is performed depending on whether or not the number of times N of refrigerant non-mixing stops N is equal to or more than a predetermined number of times (S6, S16). It may be determined whether or not the absorption liquid S is mixed in the refrigerant liquid Vf stored in the condenser 40 and / or the evaporator 20 instead of whether or not is more than a predetermined number of times. In this case, in FIG. 2, the steps (S7, S18, S23, S27, S28) related to the number of times N of refrigerant non-mixing stops can be omitted, and when the absorption liquid S is mixed in the refrigerant liquid Vf, the refrigerant is transferred. Proceeding to the step (S19) of performing the accompanying dilution operation, and in the step (S9) of stopping the absorption chiller 1 on standby when the absorption liquid S is not mixed in the refrigerant liquid Vf instead of the step (S6), the step (S9). If the absorbing liquid S is not mixed in the refrigerant liquid Vf as an alternative to S16), the process proceeds to the step (S21) of performing the dilution operation. Whether or not the absorbing liquid S is mixed in the refrigerant liquid Vf can be detected by using a hygrometer, a dew point thermometer, or the like.

In the above description, the configuration in which the cooling water D is introduced into the condenser 40 after being introduced into the absorber 11 is illustrated, but the configuration is such that the cooling water D is introduced into the absorber 11 after being introduced into the condenser 40. It may be configured to be introduced in parallel with the absorber 10 and the condenser 40.

In the above description, it is assumed that the cooling water pump 91 and the chilled water pump 92 are not components of the absorption chiller 1, but the cooling water pump 91 and / or the chilled water pump 92 is provided as a component of the absorption chiller 1. May be good. However, the cooling water D flowing by the cooling water pump 91 and the cold water C flowing by the chilled water pump 92 differ in the transport distance and the flow rate to the supply destination depending on the conditions such as the place where the absorption chiller 1 is installed. For the sake of generality, it is preferable that the cooling water pump 91 and the chilled water pump 92 are not included in the absorption chiller 1 and that the capacity suitable for the installation location of the absorption chiller 1 can be selected.

In the above description, the absorption chiller 1 has a single-effect configuration for ease of understanding, but a multiple-effect absorption chiller having a plurality of regenerators or a plurality of evaporators having different operating pressures. / It can also be applied to an absorption chiller having an absorber.

In the above explanation, the absorption chiller has been described as an absorption chiller, but it is another absorption heat source machine such as an absorption chiller-heater, an absorption heat pump, etc., in which an absorption cycle between the absorption liquid S and the refrigerant V is performed. You may.

1 Absorption Refrigerant 10 Absorber 18 Rare Solution Tube 19 Solution Pump 30 Regenerator 31 Heating Unit 38 Concentrated Solution Tube 51 Concentrated Solution Thermometer 52 Refrigerant Thermometer 55 Ambient Thermometer 60 Control Device 70 Refrigerant Liquid Mixable Part C Cold Water S Absorption Liquid Sw Rare Solution V Refrigerant Vf Refrigerant Liquid Vg Regenerator Refrigerant Steam

Claims (9)

An absorption chiller that cools or heats the fluid to be temperature-controlled by the absorption cycle of the absorption liquid and the refrigerant formed by supplying a heating source;
With a regenerator that heats the absorbing liquid that has absorbed the refrigerant with the heating source and separates the refrigerant from the absorbing liquid to increase the concentration of the absorbing liquid;
With a regenerator pressure correlation value detector that detects a physical quantity that correlates with the pressure of the regenerator or the pressure of the regenerator;
With a solution pump that flows the absorption liquid so that the absorption liquid circulates inside the absorption chiller;
A refrigerant liquid-mixable portion capable of switching between a state in which the refrigerant liquid is mixed and a state in which the refrigerant liquid is not mixed in the system in which the absorption liquid can circulate;
When the absorption chiller is stopped, the amount of heat input to the regenerator is determined while continuing the operation of the solution pump without mixing the liquid of the refrigerant into the system in which the absorption liquid can circulate. A low heating operation reduced to a calorific value is performed, and the calculated concentration, which is the concentration of the absorption solution calculated based on the value detected by the regenerator pressure correlation value detection unit during the low heating operation, is less than a predetermined value. A control device for controlling the supply mechanism of the heating source, the solution pump, and the refrigerant liquid mixing unit is provided so as to stop the supply of the heating source to the absorption chiller at the time.
Absorption chiller. The control device stops supplying the heating source to the absorption chiller when the calculated concentration does not fall below the predetermined value even after a predetermined time has elapsed since the start of the low heating operation. At the same time, the concentration of the absorption liquid is made uniform in the system in which the absorption liquid can be circulated by the operation of the solution pump, and the refrigerant liquid is mixed in the system in which the absorption liquid can be circulated by the refrigerant liquid mixing possible portion. The supply mechanism of the heating source, the solution pump, and the refrigerant liquid-mixable portion are controlled so as to perform a dilution operation for diluting the absorption liquid by performing at least one of the above;
The absorption chiller according to claim 1. It is equipped with an ambient environment temperature-related value grasping unit that grasps the ambient temperature-related value related to the ambient temperature of the absorption chiller;
The predetermined value was set to change according to the ambient temperature related value;
The absorption chiller according to claim 1 or 2. It is equipped with an absorption liquid concentration-related value grasping unit for grasping the absorption liquid concentration-related value related to the absorption liquid concentration;
In the control device, when the absorption chiller is stopped, the absorption liquid concentration-related value grasped by the absorption liquid concentration-related value grasping unit is the upper limit of the concentration at which the absorption liquid does not need to be diluted. When the concentration is equal to or lower than the upper limit, the absorption chiller is stopped without performing the low heating operation and the dilution operation for diluting the absorption liquid;
The absorption chiller according to any one of claims 1 to 3. It is equipped with an ambient environment temperature-related value grasping unit that grasps the ambient temperature-related value related to the ambient temperature of the absorption chiller;
The dilution-free upper limit concentration was set to change according to the ambient temperature-related value;
The absorption chiller according to claim 4. The control device is used when the number of stops of the absorption cycle without mixing the refrigerant liquid into a system in which the absorption liquid can be circulated by the refrigerant liquid mixing unit reaches a predetermined number of times, or when the refrigerant liquid is stopped. When it is detected that the absorbing liquid is mixed with the refrigerant in the portion where the liquid is stored, the refrigerant liquid is mixed into the system in which the absorbing liquid can circulate regardless of the value of the calculated concentration. Control the part where the refrigerant liquid can be mixed;
The absorption chiller according to any one of claims 1 to 5. When the absorption chiller is stopped, the control device performs the calculation until a predetermined operation time or a predetermined number of operations elapses after injecting the absorption liquid and the refrigerant into the absorption chiller. Regardless of the value of the concentration, the concentration of the absorption liquid is made uniform in the system in which the absorption liquid can be circulated by the operation of the solution pump, and the refrigerant in the system in which the absorption liquid can be circulated by the refrigerant liquid mixing part. The solution pump and the refrigerant liquid mixing part are controlled so as to perform a dilution operation involving both of the liquids of the above.
The absorption chiller according to any one of claims 1 to 6. A program that controls an absorption chiller that cools or heats a fluid to be temperature-controlled by an absorption cycle of an absorption liquid and a refrigerant composed of a heating source supplied;
With the absorption liquid concentration calculation step of calculating the concentration of the absorption liquid based on the pressure of the regenerator constituting the absorption chiller or the physical quantity correlating with the pressure of the regenerator;
A low heating operation step of performing a low heating operation in which the amount of heat input to the regenerator is reduced to a predetermined amount when the absorption chiller is stopped;
It includes a heating source supply stop step of stopping the supply of the heating source to the absorption chiller when the calculated concentration calculated in the absorption liquid concentration calculation step is less than a predetermined value during the low heating operation;
Control program. It is a method of controlling an absorption chiller that cools or heats a fluid to be temperature-controlled by an absorption cycle of an absorption liquid and a refrigerant formed by supplying a heating source;
With the absorption liquid concentration calculation step of calculating the concentration of the absorption liquid based on the pressure of the regenerator constituting the absorption chiller or the physical quantity correlating with the pressure of the regenerator;
A low heating operation step of performing a low heating operation in which the amount of heat input to the regenerator is reduced to a predetermined amount when the absorption chiller is stopped;
It includes a heating source supply stop step of stopping the supply of the heating source to the absorption chiller when the calculated concentration calculated in the absorption liquid concentration calculation step is less than a predetermined value during the low heating operation;
How to control the absorption chiller.

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