Absorption-type refrigerator

Abstract

To provide an adsorption-type refrigerator which can smoothly dilute absorbent for avoiding the crystallization of the absorbent resulting from excessive condensation in a regenerator and the lowering in temperature of the absorbent.SOLUTION: An adsorption-type refrigerator 1 comprises an evaporator 110b, an adsorber 110a, a regenerator 109a, and a condenser 109b whose pressure is higher than that of the evaporator 110b and which condenses refrigeration vapor Vah separated in the regenerator 109a. The adsorption-type refrigerator 1 comprises a circulation path 111 for making an adsorbent Ab separated in the regenerator 109a flow to the adsorber 110a, returning the adsorbent Ab which has adsorbed refrigeration vapor Vac in the adsorber 110a to the regenerator 109a, and making the adsorbent Ab circulate therein. The adsorption-type refrigerator 1 comprises a dilution refrigerant flow-in path 118 which is connected to the circulation path 111 and dilutes the adsorbent Ab in the circulation path 111 by making a refrigerant Re in the condenser 109b flow into the circulation path 111.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an absorption chiller. [Background technology]

[0002] 2. Description of the Related Art Absorption chillers are known in the art (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses an absorption chiller / heater (absorption chiller). This absorption chiller / heater includes an evaporator, an absorber, a condenser, a low-temperature regenerator, a high-temperature regenerator, a refrigerant pump, a dilution pipe, a dilute solution pipe, and a concentrated solution spray pipe. The evaporator is configured to cool cold water by evaporating a refrigerant. The evaporator is configured to store therein the refrigerant to be evaporated. The absorber is configured to absorb the refrigerant vapor evaporated in the evaporator into an absorption liquid. The condenser is configured to condense the refrigerant vapor heated and separated by the low-temperature regenerator and the high-temperature regenerator. The high-temperature regenerator is at a higher pressure than the evaporator.

[0004] The dilute solution pipe in the above-mentioned Patent Document 1 is configured to flow the absorption liquid diluted by absorbing the refrigerant vapor to the high-temperature regenerator. The concentrated solution spray pipe is configured to flow the absorption liquid heated and concentrated in the high-temperature regenerator to the absorber. The dilution pipe is configured to flow the refrigerant stored inside the evaporator into the high-temperature regenerator.

[0005] In the absorption chiller-heater of the above-mentioned Patent Document 1, the refrigerant stored inside the evaporator is caused to flow into the high-temperature regenerator through a dilution pipe to dilute the absorbing liquid. This dilutes the absorbing liquid so that the absorbing liquid does not crystallize due to excessive concentration in the high-temperature regenerator and a temperature drop of the absorbing liquid. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-61449 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the absorption chiller / heater of Patent Document 1, the refrigerant is caused to flow into the high-temperature regenerator, which has a higher pressure than the evaporator, and the refrigerant does not easily flow from the evaporator to the high-temperature regenerator in the dilution piping due to the pressure difference between the evaporator and the high-temperature regenerator. Therefore, the absorption chiller / heater of Patent Document 1 has a problem in that it is not possible to smoothly dilute the absorbing liquid to avoid crystallization of the absorbing liquid caused by both excessive concentration in the high-temperature regenerator (regenerator) and a temperature drop of the absorbing liquid.

[0008] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an absorption chiller that can smoothly dilute the absorbing liquid to avoid crystallization of the absorbing liquid caused by excessive concentration in the regenerator and a drop in the temperature of the absorbing liquid. [Means for solving the problem]

[0009] In order to achieve the above object, an absorption chiller in one aspect of the present invention includes an evaporator that cools a fluid by evaporating a refrigerant, an absorber that absorbs refrigerant vapor that is the refrigerant evaporated in the evaporator, a regenerator that heats the absorption liquid that has absorbed the refrigerant vapor in the absorber to separate it into refrigerant vapor and absorption liquid and regenerate the absorption liquid, a condenser that has a higher pressure than the evaporator and condenses the refrigerant vapor separated in the regenerator, a circulation path that flows the absorption liquid separated in the regenerator to the absorber and returns the absorption liquid that has absorbed the refrigerant vapor in the absorber to the regenerator and circulates the absorption liquid, and a dilution refrigerant inflow path that is connected to the circulation path and dilutes the absorption liquid in the circulation path by flowing the refrigerant in the condenser into the circulation path.

[0010] In one aspect of the present invention, the absorption chiller is provided with a dilution refrigerant inflow passage connected to the circulation passage, and diluting the absorbing liquid in the circulation passage by injecting the refrigerant in the condenser into the circulation passage. This allows the refrigerant to flow from the condenser, which has a higher pressure than the evaporator, into the circulation passage instead of the regenerator, so that the refrigerant can be easily introduced into the absorbing liquid. As a result, the absorbing liquid can be smoothly diluted to avoid excessive concentration in the regenerator and crystallization of the absorbing liquid caused by a temperature drop of the absorbing liquid. In addition, the following effects are achieved compared to the case where the refrigerant stored in the evaporator is infused into the circulation passage. That is, when the refrigerant stored in the evaporator is infused into the circulation passage, the pressure in the evaporator is in a vacuum state, so that the boiling point of the refrigerant flowing from the evaporator is lowered. In this case, the refrigerant boils due to heat conducted from the absorbing liquid in the circulation passage to the refrigerant, and bubbles are generated in the circulation passage. However, in the present invention, since the condenser is at a higher pressure than the evaporator, the pressure at the connection between the condenser and the circulation path is higher than the pressure at the connection between the evaporator and the circulation path, so that when the refrigerant flows into the circulation path, the refrigerant is less likely to boil due to heat conducted from the absorption liquid in the circulation path. As a result, it is possible to prevent bubbles caused by the boiling of the refrigerant from being generated in the circulation path, and it is possible to suppress the incorporation of bubbles in the circulation path (cavitation).

[0011] In the absorption chiller according to the above aspect, preferably, the absorption chiller further comprises a circulation pump provided in the circulation path for circulating the absorption liquid, and the dilution refrigerant inflow path is connected to a position upstream of the circulation pump in the circulation path to allow the dilution refrigerant to flow in.

[0012] With this configuration, the refrigerant can be made to flow into the circulation path by the differential pressure that causes the refrigerant to flow from the condenser, which has a higher pressure than the evaporator, into the circulation path and the suction pressure (negative pressure) of the circulation pump, so that the refrigerant can be made to flow into the circulation path more easily. As a result, the response of the dilution of the absorption liquid can be improved.

[0013] In the absorption chiller according to the aforementioned aspect, preferably, the absorption chiller further comprises a connecting pipe connecting the condenser and the evaporator, and the dilution refrigerant inflow passage includes a branch inflow passage branching from the connecting pipe and connected to the circulation passage to allow the dilution refrigerant to flow in.

[0014] With this configuration, a structure can be realized in which the dilution refrigerant is supplied to the absorbing liquid simply by connecting the connecting pipe and the circulation pipe through the branch inlet, and therefore an increase in the number of changes in the structure of the absorption chiller can be suppressed, and as a result, an absorption chiller that can further improve the response of dilution of the absorbing liquid can be easily realized.

[0015] The absorption chiller according to the above aspect preferably further comprises a dilution flow control valve provided in the dilution refrigerant inflow path for adjusting the amount of refrigerant caused to flow from the condenser into the circulation path, and a control unit for adjusting the amount of refrigerant caused to flow into the circulation path by the dilution flow control valve, each time the chiller is stopped and when the chiller is operating, based on the concentration of the absorption liquid in the circulation path.

[0016] With this configuration, an appropriate amount of refrigerant can be caused to flow into the circulation path both when the chiller is stopped and when the chiller is operating, thereby improving the response of dilution of the absorption liquid while allowing an appropriate amount of refrigerant to flow into the circulation path.

[0017] In the absorption chiller according to the above aspect, the following configuration is also possible.

[0018] (Additional note 1) In the absorption chiller equipped with the above-mentioned circulation pump, the circulation pump has a first circulation pump that flows the absorption liquid from the regenerator to the absorber in the circulation path, and a second circulation pump that flows the absorption liquid from the absorber to the regenerator in the circulation path, and the dilution refrigerant inflow path is connected to a position upstream of the first circulation pump or a position upstream of the second circulation pump to supply the dilution refrigerant.

[0019] With this configuration, the dilution refrigerant inlet passage can be connected to an appropriate location upstream of the first circulating pump or upstream of the second circulating pump depending on where the absorption chiller is installed, thereby improving the design freedom of the absorption chiller.

[0020] (Additional note 2) In the absorption chiller equipped with the above-mentioned branch inlet passage, the connecting pipe includes a condensed refrigerant flow control valve that adjusts the amount of refrigerant supplied from inside the condenser to the evaporator, and the branch inlet passage branches off from the connecting pipe upstream of the condensed refrigerant flow control valve and is connected to the circulation pipe to allow refrigerant for dilution to flow in.

[0021] With this configuration, unlike the case where the amount of refrigerant supplied from the condenser to the evaporator is adjusted by the condensed refrigerant flow control valve and then the refrigerant is flowed into the branch inlet passage, the amount of refrigerant supplied to the evaporator can be maintained at the amount adjusted by the condensed refrigerant flow control valve, thereby suppressing a decrease in the amount of evaporation of refrigerant in the evaporator.

[0022] (Additional note 3) In the absorption chiller according to the above aspect, the absorbing liquid is heated in the regenerator by utilizing exhaust heat generated in a factory.

[0023] With this configuration, the absorption liquid is heated in the regenerator using the factory's exhaust heat, making it possible to make more effective use of the thermal energy within the factory compared to the case where the absorption liquid is heated by a regenerator that includes a dedicated heating section.

[0024] (Additional note 4) In the absorption chiller according to the above aspect, the condenser includes a refrigerant reservoir provided within the condenser for storing the refrigerant condensed in the condenser, and the dilution refrigerant inflow passage is configured to cause the refrigerant in the condenser to flow into the circulation passage via the refrigerant reservoir.

[0025] With this configuration, by storing the refrigerant in the refrigerant storage section, it is possible to ensure that the refrigerant flows from the condenser into the circulation path, thereby ensuring that the refrigerant flows into the circulation path.

[0026] (Additional note 5) In the absorption chiller according to the above aspect, the regenerator, the absorber, the condenser and the evaporator are arranged so as to overlap each other at height positions with the condenser and the absorber adjacent to each other.

[0027] With this configuration, the condenser and absorber can be arranged relatively close to each other, which makes it possible to prevent the length of the dilution refrigerant inlet passage, through which the refrigerant in the condenser flows into the circulation passage, from increasing, thereby making it possible to prevent the absorption chiller from becoming large in size. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic diagram showing an absorption chiller according to a first embodiment installed in a factory. [Diagram 2] 1 is a schematic diagram showing an overall structure of an absorption chiller according to a first embodiment. FIG. [Diagram 3] FIG. 2 is a perspective view showing a regenerative condensation unit of the absorption chiller of the first embodiment. [Figure 4] FIG. 1 is a perspective view showing an evaporation absorption unit of an absorption refrigerator according to a first embodiment. [Diagram 5] FIG. 2 is a crystallization curve diagram of an absorbing liquid used in the absorption chiller of the first embodiment. [Figure 6] 4 is a flowchart showing a dilution control method for the absorption chiller of the first embodiment. [Figure 7] FIG. 5 is a schematic diagram showing the overall structure of an absorption chiller according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0030] [First embodiment] The configuration of an absorption chiller 1 of a first embodiment installed in a factory 1000 will be described with reference to Figs.

[0031] 1, an absorption chiller 1 is installed, for example, in a factory 1000 in which a processing device 2 that processes products is installed. The absorption chiller 1 is used as an air conditioning system for the factory 1000 or a cooling device for the processing device 2.

[0032] As shown in Fig. 2, in the absorption chiller 1, cooling and heating of the chilled water Wc1 are performed using a refrigerant Re and an absorbing liquid Ab. As a result, the outside air is cooled and heated by heat exchange between the outside air and the chilled water Wc1 via the heat exchanger 11. The chilled water Wc1 is an example of the "fluid" in the claims.

[0033] Here, the refrigerant Re is water, and the absorbing liquid Ab is an aqueous solution of lithium bromide (LiBr) or an aqueous solution of ammonia.

[0034] Specifically, the absorption chiller 1 includes a heat exchanger 101, a cold water circulation path 102, a cold water circulation pump 103, a radiator 104, a cooling water circulation path 105, a heat source 106, a heat medium circulation path 107, and a heat medium circulation pump 108.

[0035] The heat exchanger 101 is configured to cool (or heat) the cold water Wc1 in the cold water circulation path 102 by heat exchange with outside air. The heat exchanger 101 is, for example, an evaporator. The cold water circulation path 102 is a pipe that allows the cold water Wc1 cooled (or heated) in the evaporator 110b described below to flow through the heat exchanger 101, and returns the cold water Wc1 whose temperature has been increased (or decreased) by heat exchange with outside air in the heat exchanger 101 to the evaporator 110b, thereby circulating the cold water Wc1. The cold water circulation pump 103 is a pump for circulating the cold water Wc1 through the cold water circulation path 102. The heat exchanger 101, the cold water circulation path 102, and the cold water circulation pump 103 constitute a cold water circulation circuit.

[0036] The radiator 104 is configured to cool the cooling water Wc2 in the cooling water circulation path 105 by heat exchange with the outside air. The radiator 104 is, for example, a cooling tower or a condenser. The cooling water circulation path 105 is a pipe that sequentially flows the cooling water Wc2 cooled in the radiator 104 to an absorber 110a described later and a condenser 109b described later, and returns the cooling water Wc2 whose temperature has been reduced by heat exchange with the outside air in the radiator 104 to the absorber 110a described later, thereby circulating the cooling water Wc2. In the cooling water circulation path 105, the cooling water Wc2 circulates based on the pressure difference between the absorber 110a described later and the condenser 109b described later. The radiator 104 and the cooling water circulation path 105 constitute a cooling water circulation circuit.

[0037] The heat source 106 is configured to heat the heat medium Ht in the heat medium circulation path 107. The heat source 106 uses exhaust heat Ex (see FIG. 1) from the processing device 2 as a heat source. In this manner, the absorption chiller 1 is configured to heat the absorbing solution Ab in the regenerator 109a by utilizing the exhaust heat Ex generated in the factory 1000.

[0038] The heat medium Ht is configured to heat the absorbing liquid Ab by heat exchange with the absorbing liquid Ab in a regenerator 109a described later. The heat medium circulation path 107 is a pipe that circulates the heat medium Ht by passing the heat medium Ht heated in the heat source 106 through the regenerator 109a described later and returning the heat medium Ht whose temperature has been lowered by heat exchange with the absorbing liquid Ab in the regenerator 109a back to the heat source 106. The heat medium circulation pump 108 is a pump for circulating the heat medium Ht through the heat medium circulation path 107. The heat source 106, the heat medium circulation path 107, and the heat medium circulation pump 108 constitute a heat medium circulation circuit.

[0039] 2, the absorption chiller 1 includes a regenerative condensation unit 109, an evaporation absorption unit 110, a circulation path 111, a heat exchanger 112, a temperature sensor 113, a concentration side circulation pump 114 (first circulation pump), a dilution side circulation pump 115 (second circulation pump), a connecting pipe 116, a connecting pipe 117, a dilution refrigerant inflow path 118, and a control unit 119. Each of the concentration side circulation pump 114 and the dilution side circulation pump 115 is an example of a "circulation pump" in the claims.

[0040] Here, the direction in which the regenerative condensation unit 109 and the evaporative absorption unit 110 face each other is the X direction, the direction from the evaporative absorption unit 110 toward the regenerative condensation unit 109 is the X1 direction, and the opposite direction is the X2 direction. The vertical direction is the Z direction, the upward direction is the Z1 direction, and the downward direction is the Z2 direction. The direction perpendicular to the X direction and the Z direction is the Y direction, one of which is the Y1 direction and the other is the Y2 direction. The horizontal direction is the XY direction. In FIG. 2, the flow path through which the refrigerant Re flows is indicated by a thick dotted line. The flow path through which the concentrated absorption liquid Abc flows as the absorption liquid Ab is indicated by a thick line, and the flow path through which the diluted absorption liquid Abi flows is indicated by a thick dashed line.

[0041] (Regenerative Condensing Unit) The regenerator 109 is a unit that integrally incorporates the regenerator 109a and the condenser 109b. The regenerator 109 includes the regenerator 109a, the condenser 109b, a housing 109c, and a pressure sensor 109d. The combination of the regenerator 109a and the housing 109c is an example of a "regenerator" in the claims. The combination of the condenser 109b and the housing 109c is an example of a "condenser" in the claims.

[0042] The regenerator 109a is configured to heat the diluted absorbing solution Abi that has absorbed the refrigerant vapor Vac in the absorber 110a described later, thereby separating the diluted absorbing solution Abi into the refrigerant vapor Vah and the concentrated absorbing solution Abc to regenerate the absorbing solution Ab. The regenerator 109a has a heat exchanger 1091a, a rotary applicator 1092a, and a motor (not shown).

[0043] The heat exchanger 1091a is configured to heat each of the diluted absorbing solution Abi and the concentrated absorbing solution Abc by exchanging heat between the heat medium Ht and each of the diluted absorbing solution Abi and the concentrated absorbing solution Abc. The heat exchanger 1091a has a heat transfer tube (not shown) through which the heat medium Ht flows. A plurality of (five) heat exchangers 1091a are arranged in the Y direction (see FIG. 3). The rotary applicator 1092a is configured to rotate via a rotary shaft by a motor in the housing 109c. In the housing 109c, the concentrated absorbing solution Abc stored on the Z2 direction side is pumped up as the rotary applicator 1092a rotates, and is evenly applied to the heat exchanger 1091a. The number of heat exchangers 1091a may be one or more, four or less, or six or more.

[0044] The condenser 109b is configured to cool and condense the refrigerant vapor Vah separated in the regenerator 109a. The condensed refrigerant vapor Vah is the refrigerant Re. The condenser 109b includes a heat exchanger 1091b, a rotary applicator 1092b, and a motor (not shown).

[0045] The heat exchanger 1091b is configured to cool the refrigerant vapor Vah and the refrigerant Re by exchanging heat between the cooling water Wc2 and each of the refrigerant vapor Vah and the refrigerant Re. The heat exchanger 1091b has a heat transfer tube (not shown) through which the cooling water Wc2 flows. A plurality of (five) heat exchangers 1091b are arranged in the Y direction (see FIG. 3). The spin applicator 1092b is configured to rotate via a rotating shaft by a motor in the housing 109c. In the housing 109c, the refrigerant Re stored on the Z2 direction side is pumped up as the spin applicator 1092b rotates, and is evenly applied to the heat exchanger 1091b. The number of heat exchangers 1091b may be one or more, four or less, or six or more.

[0046] The housing 109c accommodates therein the regenerator 109a, the condenser 109b, and the pressure sensor 109d. The pressure inside the housing 109c is higher than the pressure inside the evaporation absorption unit 110. That is, the pressure inside the housing 109c is higher than the pressure inside the evaporator 110b (or the absorber 110a). Here, the pressure inside the housing 109c is, for example, about 10 kPa when the absorption chiller 1 is in operation. The housing 109c has a partition wall 1091c (see FIG. 3) that separates the concentrated absorption liquid Abc stored on the Z2 direction side from the refrigerant Re stored on the Z2 direction side.

[0047] The concentrated absorbing liquid Abc is separated by a partition wall 1091c and stored in a concentrated absorbing liquid storage section at a position where the regenerator 109a is disposed in the housing 109c. The concentrated absorbing liquid Abc is stored up to a position where a part of the regenerator 109a on the Z2 direction side is immersed. In this way, the concentrated absorbing liquid storage section is a space that stores the concentrated absorbing liquid Abc separated in the regenerator 109a in the housing 109c.

[0048] The refrigerant Re is stored in a refrigerant reservoir at a position where the condenser 109b is disposed in the housing 109c, separated by the partition wall 1091c. The refrigerant Re is stored up to a position where the Z2 direction side of the condenser 109b is immersed. In this way, the refrigerant reservoir is a space that stores the refrigerant Re condensed in the condenser 109b in the housing 109c.

[0049] The pressure sensor 109d is configured to measure the pressure inside the housing 109c that houses the regenerator 109a and the condenser 109b.

[0050] (Evaporation absorption unit) The evaporation absorption unit 110 is a unit that integrally incorporates an absorber 110a and an evaporator 110b. The evaporation absorption unit 110 includes the absorber 110a, the evaporator 110b, a housing 110c, and a pressure sensor 110d. The combination of the absorber 110a and the housing 110c is an example of an "absorber" in the claims. The combination of the evaporator 110b and the housing 110c is an example of an "evaporator" in the claims.

[0051] The absorber 110a is configured to absorb refrigerant vapor Vac, which is the refrigerant Re evaporated in the evaporator 110b. The absorber 110a includes a heat exchanger 1101a, a rotary applicator 1102a, and a motor (not shown).

[0052] The heat exchanger 1101a is configured to cool the cooling water Wc2 by exchanging heat between the cooling water Wc2 and each of the diluted absorption liquid Abi and the concentrated absorption liquid Abc. The heat exchanger 1101a has a heat transfer tube (not shown) through which the cooling water Wc2 flows. A plurality of (five) heat exchangers 1101a are arranged in the Y direction (see FIG. 4). The spin applicator 1102a is configured to rotate via a rotating shaft by a motor in the housing 110c. In the housing 110c, the diluted absorption liquid Abi stored on the Z2 direction side is pumped up as the spin applicator 1102a rotates, and is evenly applied to the heat exchanger 1101a. The number of heat exchangers 1101a may be one or more, four or less, or six or more.

[0053] The evaporator 110b is configured to cool the cold water Wc1 by evaporating the refrigerant Re. The evaporator 110b includes a heat exchanger 1101b, a rotary applicator 1102b, and a motor (not shown).

[0054] The heat exchanger 1101b is configured to cool the refrigerant vapor Vac and the refrigerant Re by exchanging heat between the cold water Wc1 and each of the refrigerant vapor Vac and the refrigerant Re. The heat exchanger 1101b has a heat transfer tube (not shown) through which the cold water Wc1 flows. A plurality of (five) heat exchangers 1101b are arranged in the Y direction (see FIG. 4). The spin applicator 1102b is configured to rotate via a rotating shaft by a motor in the housing 110c. In the housing 110c, the refrigerant Re stored on the Z2 direction side is pumped up as the spin applicator 1102b rotates, and is evenly applied to the heat exchanger 1101b. The number of heat exchangers 1101b may be one or more, four or less, or six or more.

[0055] The casing 110c accommodates the absorber 110a and the evaporator 110b therein. The pressure inside the casing 110c is lower than the pressure inside the regenerative condensing unit 109. Here, the pressure inside the casing 110c is, for example, about 1 kPa when the absorption chiller 1 is in operation. That is, the pressure inside the casing 110c is maintained in a low-pressure vacuum state in order to evaporate the refrigerant Re by the cold water Wc1. The casing 110c has a partition wall 1101c (see FIG. 4) that separates the diluted absorption liquid Abi stored on the Z2-direction side from the refrigerant Re stored on the Z2-direction side.

[0056] The diluted absorbent Abi is separated by the partition wall 1101c and stored in the diluted absorbent storage section at the position where the absorber 110a is arranged in the housing 110c. The diluted absorbent Abi is stored up to a position where the Z2 direction side of the absorber 110a is immersed. In this way, the diluted absorbent storage section is a space that stores the diluted absorbent Abi separated in the absorber 110a in the housing 110c.

[0057] The refrigerant Re is separated by the partition wall 1101c and stored in a refrigerant storage section at the position where the evaporator 110b is disposed in the housing 110c. The refrigerant Re is stored up to a position where the Z2 direction side of the evaporator 110b is immersed. In this way, the refrigerant storage section is a space that stores the refrigerant Re condensed in the evaporator 110b in the housing 110c.

[0058] The pressure sensor 110d is configured to measure the pressure within the housing 110c that houses the absorber 110a and the evaporator 110b.

[0059] (Location of regenerative condensation unit and evaporation absorption unit) 2, the regenerator condenser unit 109 and the evaporator absorption unit 110 having the above-mentioned configuration are arranged so that their height positions are aligned in the Z direction. The regenerator 109 and the evaporator absorption unit 110 are arranged adjacent to each other in the X direction. The regenerator 109a, the absorber 110a, the condenser 109b, and the evaporator 110b are arranged so that their height positions overlap with each other, with the condenser 109b and the absorber 110a adjacent to each other.

[0060] (circulation route) 2, the circulation path 111 is configured to flow the concentrated absorption solution Abc separated in the regenerator 109a to the absorber 110a, and to return the diluted absorption solution Abi that has absorbed the refrigerant vapor Vac in the absorber 110a to the regenerator 109a, thereby circulating the absorption solution Ab. That is, the circulation path 111 is a pipe that circulates the absorption solution Ab between the regeneration condensation unit 109 and the evaporation absorption unit 110.

[0061] The pipe of the circulation path 111 extending from the regenerator 109a to the absorber 110a connects the concentrated absorbing liquid storage section of the regeneration-condensation unit 109 to a portion of the evaporative absorption unit 110 on the Z1 direction side of the diluted absorbing liquid storage section. The pipe of the circulation path 111 extending from the absorber 110a to the regenerator 109a connects the diluted absorbing liquid storage section of the evaporative absorption unit 110 to a portion of the regeneration-condensation unit 109 on the Z1 direction side of the concentrated absorbing liquid storage section.

[0062] (Heat exchanger, temperature sensor, concentrated side circulation pump and dilution side circulation pump) The heat exchanger 112 is configured to exchange heat between the high-temperature concentrated absorbing solution Abc flowing out from the regenerator 109a and the low-temperature diluted absorbing solution Abi flowing out from the absorber 110a. This allows the concentrated absorbing solution Abc flowing into the absorber 110a to be cooled, and the diluted absorbing solution Abi flowing into the regenerator 109a to be heated.

[0063] The temperature sensor 113 is configured to measure the temperature of the concentrated absorption solution Abc immediately after it flows out of the regenerator 109a. The temperature sensor 113 is disposed upstream of the heat exchanger 112 (on the regenerator 109a side) in the flow path of the circulation path 111 from the regenerator 109a to the absorber 110a.

[0064] Each of the concentration-side circulation pump 114 and the dilution-side circulation pump 115 is a pump for circulating the absorption liquid Ab. Each of the concentration-side circulation pump 114 and the dilution-side circulation pump 115 is provided in the circulation path 111. That is, the concentration-side circulation pump 114 is a pump for flowing the concentrated absorption liquid Abc from the regenerator 109a to the absorber 110a in the circulation path 111. The concentration-side circulation pump 114 is disposed downstream (on the absorber 110a side) of the heat exchanger 112 in the flow path from the regenerator 109a to the absorber 110a in the circulation path 111. The dilution-side circulation pump 115 is a pump for flowing the diluted absorption liquid Abi from the absorber 110a to the regenerator 109a in the circulation path 111. The dilution side circulation pump 115 is disposed upstream of the heat exchanger 112 (on the absorber 110a side) in the flow path of the circulation path 111 from the absorber 110a toward the regenerator 109a.

[0065] (Connecting Pipes) The connecting pipe 116 is a pipe through which the refrigerant Re flows from the regenerative condensing unit 109 to the evaporative absorption unit 110. The connecting pipe 116 uses the pressure difference between the regenerative condensing unit 109 and the evaporative absorption unit 110 to make the refrigerant Re flow. The connecting pipe 116 connects a refrigerant reservoir of the regenerative condensing unit 109 to a portion of the evaporative absorption unit 110 on the Z1 direction side of the refrigerant reservoir. The connecting pipe 116 is provided with a condensed refrigerant flow rate control valve 116a. The condensed refrigerant flow rate control valve 116a is configured to adjust the amount of refrigerant Re supplied from the refrigerant reservoir (inside the condenser 109b) in the housing 109c to the evaporator 110b.

[0066] The connection pipe 117 is a pipe through which the refrigerant Re flows from the evaporation absorption unit 110 to the circulation path 111. In the connection pipe 117, the refrigerant Re flows by utilizing the weight of the refrigerant Re due to gravity. The connection pipe 117 connects the refrigerant storage part of the evaporation absorption unit 110 to the upstream side (the absorber 110a side) of the dilution side circulation pump 115 in the flow path from the absorber 110a to the regenerator 109a of the circulation path 111. The connection pipe 117 is provided with an evaporated refrigerant flow rate control valve 117a. The evaporated refrigerant flow rate control valve 117a is configured to adjust the amount of refrigerant Re supplied to the circulation path 111 from the refrigerant storage part (inside the evaporator 110b) in the housing 110c.

[0067] (Dilution refrigerant inlet passage) The dilution refrigerant inflow passage 118 of the first embodiment is configured to dilute the absorbing solution Ab in the circulation passage 111 by causing the refrigerant Re in the condenser 109b to flow into the circulation passage 111. Here, the dilution refrigerant inflow passage 118 connects the regeneration condensation unit 109 and a predetermined position of the circulation passage 111. The dilution refrigerant inflow passage 118 is configured to cause the refrigerant Re in the condenser 109b to flow into the circulation passage 111 via a refrigerant reservoir of the regeneration condensation unit 109.

[0068] That is, the dilution refrigerant inflow passage 118 connects a refrigerant storage section in the housing 109c of the regeneration condensation unit 109 to the upstream side of the dilution-side circulation pump 115 in the flow path from the absorber 110a to the regenerator 109a of the circulation passage 111. As a result, the dilution refrigerant inflow passage 118 is configured to make the refrigerant Re flow into the circulation passage 111 by utilizing the pressure difference between the regeneration condensation unit 109 and the evaporation absorption unit 110 and the suction pressure (negative pressure) on the inlet side of the dilution-side circulation pump 115.

[0069] Specifically, the dilution refrigerant inflow passage 118 has a common inflow passage 118a, a branch inflow passage 118b, and a dilution flow rate adjustment valve 118c.

[0070] The common inflow path 118a is a portion upstream (condenser 109b side) of the condensed refrigerant flow rate adjustment valve 116a of the connection pipe 116. In other words, the common inflow path 118a is a portion common to the pipe through which the refrigerant Re flows from the regeneration condensation unit 109 to the evaporation absorption unit 110.

[0071] The branch inlet passage 118b of the dilution refrigerant inlet passage 118 branches off from the connecting pipe 116 and is connected to the circulation passage 111 in order to allow the dilution refrigerant Re to flow in. That is, the branch inlet passage 118b branches off from the upstream side of the condensed refrigerant flow rate control valve 116a of the connecting pipe 116 and is connected to the circulation passage 111 in order to allow the dilution refrigerant Re to flow in. Also, the branch inlet passage 118b of the dilution refrigerant inlet passage 118 is connected to a position upstream of the dilution side circulation pump 115 (the absorber 110a side) in the circulation passage 111 in order to allow the dilution refrigerant Re to flow in.

[0072] As a result, the upstream side (condenser 109b side) of the dilution refrigerant inflow passage 118 in the flow direction of the refrigerant Re is connected to the regeneration condensation unit 109, so that pressure is generated in the casing 109c. Also, the downstream side (circulation passage 111 side) of the dilution refrigerant inflow passage 118 in the flow direction of the refrigerant Re is connected to a portion of the circulation passage 111 extending from the evaporation absorption unit 110, so that pressure is generated in the casing 110c. Therefore, it is possible to cause the refrigerant Re to flow into the circulation passage 111 due to the pressure difference between the pressure in the casing 109c and the pressure in the casing 110c and the suction pressure (negative pressure) of the dilution side circulation pump 115.

[0073] The dilution flow rate adjustment valve 118c is configured to adjust the amount of refrigerant Re flowing from the condenser 109b into the circulation path 111. The dilution flow rate adjustment valve 118c is provided in the branch inlet path 118b of the dilution refrigerant inlet path 118.

[0074] (Control unit) As shown in FIG. 2, the control unit 119 is configured to control each part of the absorption chiller 1. The control unit 119 includes a central processing unit (CPU), memories such as a read only memory (ROM) and a RAM, and a storage unit having a solid state drive (SSD) or a hard disk drive (HDD). The storage unit stores a control program for controlling each part of the absorption chiller 1. In addition, in order to avoid crystallization of the absorption solution Ab, a dilution control table is stored in which the concentration of the absorption solution Ab is associated with the opening degree and the open maintenance time of the dilution flow control valve 118c, which is used when controlling the dilution of the absorption solution Ab. In addition, the storage unit stores a stop target dilution concentration when the absorption chiller 1 is stopped. In addition, the storage unit stores an operating dilution start concentration when the absorption chiller 1 is operating.

[0075] The control unit 119 is electrically connected to each of the cold water circulation pump 103, the heating source 106, the heat medium circulation pump 108, the pressure sensor 109d, the pressure sensor 110d, the temperature sensor 113, the concentration side circulation pump 114, the dilution side circulation pump 115, the condensing refrigerant flow control valve 116a, the evaporating refrigerant flow control valve 117a and the dilution flow control valve 118c.

[0076] Here, the control unit 119 is configured to perform control to adjust the amount of refrigerant Re flowing into the circulation path 111 by the dilution flow control valve 118c, both when the absorption chiller 1 is stopped and when the absorption chiller 1 is operating, based on the concentration of the absorption liquid Ab in the circulation path 111.

[0077] The control unit 119 is configured to perform control to acquire the concentration of the concentrated absorbing solution Abc in the circulation path 111 as the concentration of the absorbing solution Ab based on the difference between the pressure of the condenser 109b and the pressure of the absorber 110a and the temperature of the concentrated absorbing solution Abc. The difference between the pressure of the condenser 109b and the pressure of the absorber 110a is calculated based on the difference between the pressure value in the housing 109c (in the condenser 109b) measured by the pressure sensor 109d and the pressure value measured in the housing 109c (in the condenser 109b). The temperature of the concentrated absorbing solution Abc is the temperature of the concentrated absorbing solution Abc in the circulation path 111 measured by the temperature sensor 113.

[0078] As a result, the control unit 119 is configured to perform control to maintain the opening degree of the dilution flow rate adjustment valve 118c during the open maintenance time based on the acquired concentration of the concentrated absorbing solution Abc and the dilution control table.

[0079] <When the absorption chiller is stopped> Specifically, the control unit 119 is configured to perform control to maintain the opening degree of the dilution flow rate adjustment valve 118c during the open maintenance time based on the concentration of the concentrated absorbing solution Abc acquired based on the reception of a stop signal when the absorption chiller 1 is stopped and based on the dilution control table. The control unit 119 is configured to perform control to acquire the concentration of the concentrated absorbing solution Abc based on the lapse of the open maintenance time. The control unit 119 is configured to perform control to determine whether the concentration of the concentrated absorbing solution Abc after the open maintenance time is equal to or higher than the target dilution concentration at the time of stopping. When the concentration of the concentrated absorbing solution Abc after the open maintenance time is equal to or higher than the target dilution concentration at the time of stopping, the control unit 119 is further configured to perform control to maintain the opening degree of the dilution flow rate adjustment valve 118c during the open maintenance time based on the acquired concentration of the concentrated absorbing solution Abc and the dilution control table. Moreover, the control unit 119 is configured to continue the control to stop the absorption chiller 1 when the concentration of the concentrated absorbing solution Abc after the open maintenance time is lower than the target dilution concentration at the time of stopping.

[0080] <When the absorption chiller is operating> Specifically, the control unit 119 is configured to perform control to determine whether or not the acquired concentration of the concentrated absorbing solution Abc is equal to or higher than the dilution start concentration during operation of the absorption chiller 1. When the concentration of the concentrated absorbing solution Abc is equal to or higher than the dilution start concentration during operation, the control unit 119 is configured to perform control to maintain the opening degree of the dilution flow rate adjustment valve 118c during the open maintenance time based on the acquired concentration of the concentrated absorbing solution Abc and the dilution control table. The control unit 119 is configured to perform control to acquire the concentration of the concentrated absorbing solution Abc based on the lapse of the open maintenance time. The control unit 119 is configured to perform control to determine whether or not the concentration of the concentrated absorbing solution Abc after the open maintenance time is equal to or higher than the dilution start concentration during operation. When the concentration of the concentrated absorbing solution Abc after the open maintenance time is equal to or higher than the dilution start concentration during operation, the control unit 119 is further configured to perform control to maintain the opening degree of the dilution flow rate adjustment valve 118c during the open maintenance time based on the acquired concentration of the concentrated absorbing solution Abc and the dilution control table. Moreover, the control unit 119 is configured to end the dilution control when the concentration of the concentrated absorbing solution Abc after the open maintenance time is less than the dilution start concentration during operation.

[0081] Here, based on the crystallization curve of the lithium bromide (LiBr) aqueous solution shown in Fig. 5, the target dilution concentration during shutdown is set to 59% in summer and 56% in winter, as an example, and the dilution start concentration during operation is set to 62.5%, as an example.

[0082] (Dilution control method) Here, a dilution control method for diluting the absorbing liquid Ab will be described with reference to FIG.

[0083] In step S1, it is determined whether the absorption chiller 1 is in operation. If the absorption chiller 1 is in operation, the process proceeds to step S2. If the absorption chiller 1 is not in operation, the process proceeds to step S5. In step S2, the concentration of the concentrated absorption solution Abc is acquired. In step S3, it is determined whether the acquired concentration is equal to or higher than the dilution start concentration during operation. If the acquired concentration is equal to or higher than the dilution start concentration during operation, the process proceeds to step S4. If the acquired concentration is lower than the dilution start concentration during operation, the dilution control method is terminated. In step S4, the aperture of the dilution flow rate control valve 118c is adjusted based on the acquired concentration and the dilution control table, and the aperture is maintained for the open maintenance time. After the open maintenance time has elapsed, the process returns to step S2 and the process is repeated.

[0084] In step S5, it is determined whether the absorption refrigerator 1 is stopped. If the absorption refrigerator 1 is stopped, the process proceeds to step S6. If the absorption refrigerator 1 is not stopped, the dilution control method is terminated. In step S6, the concentration of the concentrated absorption liquid Abc is acquired. In step S7, it is determined whether the acquired concentration is equal to or greater than the target dilution concentration at the time of stopping. If the acquired concentration is equal to or greater than the target dilution concentration at the time of stopping, the process proceeds to step S8. If the acquired concentration is less than the target dilution concentration at the time of stopping, the dilution control method is terminated. In step S8, the aperture of the dilution flow rate adjustment valve 118c is adjusted based on the acquired concentration and the dilution control table, and the aperture is maintained for the open maintenance time. Then, after the open maintenance time has elapsed, the process returns to step S6 and is repeated.

[0085] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0086] In the first embodiment, as described above, the absorption chiller 1 is connected to the circulation path 111 and includes a dilution refrigerant inflow path 118 for diluting the absorbing solution Ab in the circulation path 111 by flowing the refrigerant Re in the condenser 109b into the circulation path 111. As a result, the refrigerant Re is flowed from the condenser 109b, which has a higher pressure than the evaporator 110b, into the circulation path 111 instead of the regenerator 109a, so that the refrigerant Re can be easily flowed into the absorbing solution Ab. As a result, the dilution of the absorbing solution Ab can be smoothly performed to avoid crystallization of the absorbing solution Ab caused by each of excessive heating in the regenerator 109a and a temperature drop of the absorbing solution Ab. In addition, the following effects are achieved compared to the case where the refrigerant Re stored in the evaporator 110b is flowed into the circulation path 111. That is, when the refrigerant Re stored in the evaporator 110b is flowed into the circulation path 111, the pressure in the evaporator 110b is in a vacuum state, so the boiling point of the refrigerant Re flowing from the evaporator 110b is lowered. In this case, the refrigerant Re boils due to heat conducted from the absorption liquid Ab in the circulation path 111 to the refrigerant Re, and bubbles are generated in the circulation path 111. However, in the present invention, the condenser 109b is at a higher pressure than the evaporator 110b, so that the pressure at the connection part between the condenser 109b and the circulation path 111 is higher than the pressure at the connection part between the evaporator 110b and the circulation path 111. Therefore, when the refrigerant Re flows into the circulation path 111, the refrigerant Re is unlikely to boil due to heat conducted from the absorption liquid Ab in the circulation path 111. As a result, it is possible to prevent bubbles caused by the boiling of the refrigerant Re from being generated in the circulation path 111, so that the inclusion of bubbles in the circulation path 111 (cavitation) can be suppressed.

[0087] In the first embodiment, as described above, the absorption chiller 1 is provided in the circulation path 111 and includes the concentrated-side circulation pump 114 (first circulation pump) for circulating the absorption liquid Ab. The dilution refrigerant inflow path 118 is connected to a position upstream of the concentrated-side circulation pump 114 (first circulation pump) in the circulation path 111 in order to allow the dilution refrigerant Re to flow in. This allows the refrigerant Re to flow into the circulation path 111 by a differential pressure that allows the refrigerant Re to flow from the condenser 109b, which has a higher pressure than the evaporator 110b, into the circulation path 111 and the suction pressure (negative pressure) of the concentrated-side circulation pump 114 (first circulation pump), so that the refrigerant Re can be made to flow into the circulation path 111 more easily. As a result, the responsiveness of dilution of the absorption liquid Ab can be further improved.

[0088] In the first embodiment, as described above, the absorption chiller 1 includes the connection pipe 116 that connects the condenser 109b and the evaporator 110b. The dilution refrigerant inflow passage 118 includes a branch inflow passage 118b that branches from the connection pipe 116 and connects to the circulation passage 111 in order to allow the dilution refrigerant Re to flow in. This makes it possible to realize a structure in which the dilution refrigerant Re is supplied to the absorbing liquid Ab simply by connecting the connection pipe 116 and the circulation passage 111 via the branch inflow passage 118b, thereby making it possible to suppress an increase in the number of structural changes in the absorption chiller 1. As a result, it is possible to easily realize an absorption chiller 1 that can further improve the responsiveness of dilution of the absorbing liquid Ab.

[0089] In the first embodiment, as described above, the absorption chiller 1 includes the dilution flow rate control valve 118c that is provided in the dilution refrigerant inflow passage 118 and adjusts the amount of refrigerant Re that is caused to flow from the condenser 109b into the circulation passage 111. The absorption chiller 1 includes a control unit 119 that adjusts the amount of refrigerant Re that is caused to flow into the circulation passage 111 by the dilution flow rate control valve 118c, based on the concentration of the absorbing liquid Ab in the circulation passage 111, both when the chiller is stopped and when the chiller is operating. This allows an appropriate amount of refrigerant Re to flow into the circulation passage 111 both when the chiller is stopped and when the chiller is operating, and therefore allows an appropriate amount of refrigerant Re to flow into the circulation passage 111 while improving the responsiveness of dilution of the absorbing liquid Ab.

[0090] [Second embodiment] The configuration of an absorption chiller 201 according to the second embodiment will be described with reference to Fig. 7. In the second embodiment, a dilution refrigerant inlet passage 218 is connected to a pipe in a circulation passage 111 extending from the condenser 109b toward the absorber 110a. Note that in the second embodiment, detailed description of the same configuration as in the first embodiment will be omitted.

[0091] As shown in Fig. 7, in the absorption chiller 201, the chilled water Wc1 is cooled and heated using the refrigerant Re and the absorbing liquid Ab. Thus, the outside air is cooled and heated by heat exchange between the outside air and the chilled water Wc1 via the heat exchanger 11. The chilled water Wc1 is an example of the "fluid" in the claims.

[0092] Specifically, the absorption chiller 201 includes a regenerative condensation unit 109, an evaporation absorption unit 110, a circulation path 111, a heat exchanger 112, a temperature sensor 113, a concentration side circulation pump 114 (first circulation pump), a dilution side circulation pump 115 (second circulation pump), a connecting pipe 116, a connecting pipe 117, a dilution refrigerant inflow path 218, and a control unit 119. Each of the concentration side circulation pump 114 and the dilution side circulation pump 115 is an example of a "circulation pump" in the claims.

[0093] Here, the direction in which the regenerative condensation unit 109 and the evaporative absorption unit 110 face each other is the X direction, the direction from the evaporative absorption unit 110 toward the regenerative condensation unit 109 is the X1 direction, and the opposite direction is the X2 direction. The vertical direction is the Z direction, the upward direction is the Z1 direction, and the downward direction is the Z2 direction. The direction perpendicular to the X direction and the Z direction is the Y direction, one of which is the Y1 direction and the other is the Y2 direction. The horizontal direction is the XY direction. In FIG. 7, the flow path through which the refrigerant Re flows is indicated by a thick dotted line. The flow path through which the concentrated absorption liquid Abc flows as the absorption liquid Ab is indicated by a thick line, and the flow path through which the diluted absorption liquid Abi flows is indicated by a thick dashed line.

[0094] (Dilution refrigerant inlet passage) The dilution refrigerant inflow passage 218 of the second embodiment is configured to dilute the absorbing liquid Ab in the circulation passage 111 by causing the refrigerant Re in the condenser 109b to flow into the circulation passage 111.

[0095] That is, the dilution refrigerant inflow passage 218 connects a refrigerant storage section in the housing 109c of the regeneration condensation unit 109 to the upstream side of the concentration-side circulation pump 114 in the flow path from the regenerator 109a to the absorber 110a of the circulation passage 111. As a result, the dilution refrigerant inflow passage 218 is configured to make the refrigerant Re flow into the circulation passage 111 by utilizing the pressure difference between the regeneration condensation unit 109 and the evaporation absorption unit 110 and the suction pressure (negative pressure) on the inlet side of the concentration-side circulation pump 114.

[0096] Specifically, the dilution refrigerant inflow passage 218 has a common inflow passage 218a, a branch inflow passage 218b, and a dilution flow rate adjustment valve 118c.

[0097] The common inflow path 218a is a portion upstream (condenser 109b side) of the condensed refrigerant flow rate adjustment valve 116a of the connection pipe 116. In other words, the common inflow path 218a is a portion common to the pipe through which the refrigerant Re flows from the regeneration condensation unit 109 to the evaporation absorption unit 110.

[0098] The branch inlet path 218b of the dilution refrigerant inflow path 218 branches off from the connection pipe 116 and connects to the circulation path 111 in order to allow the dilution refrigerant Re to flow in. That is, the branch inlet path 218b branches off from the upstream side of the condensed refrigerant flow rate control valve 116a of the connection pipe 116 and connects to the circulation path 111 in order to allow the dilution refrigerant Re to flow in. Also, the branch inlet path 218b of the dilution refrigerant inflow path 218 is connected to a position on the upstream side (absorber 110a side) of the concentration-side circulation pump 114 in the circulation path 111 in order to allow the dilution refrigerant Re to flow in. This allows the refrigerant Re to flow into the circulation path 111 due to the pressure difference between the pressure in the housing 109c and the pressure in the housing 110c and the suction pressure (negative pressure) of the concentration-side circulation pump 114. In addition, since the pressure on the discharge side of the concentration side circulation pump 114 is lower than the pressure inside the casing 109c, the diluted absorbent Ab can be circulated inside the circulation path 111 efficiently.

[0099] The other configurations of the second embodiment are similar to those of the first embodiment, so the description will be omitted.

[0100] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0101] In the second embodiment, similarly to the first embodiment, the absorption chiller 201 is connected to the circulation path 111 and includes a dilution refrigerant inflow path 218 for diluting the absorbing solution Ab in the circulation path 111 by causing the refrigerant Re in the condenser 109b to flow into the circulation path 111. This makes it possible to smoothly dilute the absorbing solution Ab to avoid crystallization of the absorbing solution Ab caused by both excessive heating in the regenerator 109a and a temperature drop of the absorbing solution Ab.

[0102] The other effects of the second embodiment are similar to those of the first embodiment, and therefore a description thereof will be omitted.

[0103] [Variations] The above-described embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the above-described embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0104] For example, in the above first and second embodiments, the absorption chiller 1 (201) is installed in a factory 1000 in which a processing device 2 that processes products is installed, but the present invention is not limited to this. In the present invention, the absorption chiller may be applied to vehicles (mobiles) including electric vehicles, hybrid vehicles, gasoline vehicles, and the like. In this case, in the absorption chiller, each of the regenerator, condenser, absorber, and evaporator may tilt due to the movement of the vehicle, so that they are covered with a thin film that allows the passage of refrigerant vapor but does not allow the passage of absorption liquid and liquid refrigerant.

[0105] In the above first and second embodiments, the heat source 106 uses the exhaust heat Ex from the processing device 2 as a heat source, but the present invention is not limited to this. In the present invention, the heat source may be exhaust heat from exhaust gas, exhaust heat from electrical equipment, exhaust heat from a battery, or heating by a dedicated heater.

[0106] In the first and second embodiments, the concentrate-side circulation pump 114 is provided in the pipe extending from the regenerator 109a to the absorber 110a in the circulation path 111, but the present invention is not limited to this. In the present invention, the concentrate-side circulation pump does not have to be provided in the circulation path.

[0107] In the above first and second embodiments, the regenerator 109a includes the heat exchanger 1091a and the rotary applicator 1092a, but the present invention is not limited to this. In the present invention, the regenerator may include a nozzle that sprays the diluted absorbing liquid onto the heat exchanger.

[0108] In the above first and second embodiments, the condenser 109b includes the heat exchanger 1091b and the spin-applying body 1092b, but the present invention is not limited to this. In the present invention, the condenser may include a nozzle that sprays a refrigerant onto the heat exchanger.

[0109] In the above first and second embodiments, the absorber 110a includes the heat exchanger 1101a and the rotary applicator 1102a, but the present invention is not limited to this. In the present invention, the absorber may include a nozzle that sprays the concentrated absorbing liquid onto the heat exchanger.

[0110] In the above first and second embodiments, the evaporator 110b includes the heat exchanger 1101b and the spin-applying body 1102b, but the present invention is not limited to this. In the present invention, the evaporator may include a nozzle that sprays a refrigerant onto the heat exchanger.

[0111] In the above first and second embodiments, the control unit 119 is configured to perform control to acquire the concentration of the concentrated absorbing liquid Abc in the circulation path 111 as the concentration of the absorbing liquid Ab based on the difference between the pressure of the condenser 109b and the pressure of the absorber 110a and the temperature of the concentrated absorbing liquid Abc, but the present invention is not limited to this. In the present invention, the control unit may be configured to perform control to acquire the concentration of the concentrated absorbing liquid in the circulation path based on a measurement signal of a density meter that measures the density of the concentrated absorbing liquid.

[0112] In the above first and second embodiments, the regenerator 109a, absorber 110a, condenser 109b, and evaporator 110b are arranged so that their height positions overlap with each other, with the condenser 109b and absorber 110a adjacent to each other, but the present invention is not limited to this. In the present invention, the regenerator, absorber, condenser, and evaporator do not have to be arranged so that their height positions overlap with each other, with the condenser and absorber adjacent to each other.

[0113] In the above first and second embodiments, the regenerator 109a and the condenser 109b are integrally built into the regenerator 109a and the condenser 109b, but the present invention is not limited to this. In the present invention, the regenerator and the condenser do not have to be unitized.

[0114] In the above first and second embodiments, the evaporation absorption unit 110 is an example of a unit that integrally incorporates the absorber 110a and the evaporator 110b, but the present invention is not limited to this. In the present invention, the absorber and the evaporator do not need to be unitized.

[0115] In the above first and second embodiments, for convenience of explanation, an example is shown in which the control process of the control unit 119 is explained using a flow-driven flowchart in which the process is performed in order according to the process flow, but the present invention is not limited to this. In the present invention, the control process of the control unit may be performed by event-driven processing in which processing is performed on an event-by-event basis. In this case, the control process may be performed completely event-driven, or may be performed in a combination of event-driven and flow-driven. [Explanation of symbols]

[0116] 1, 201 Absorption chiller 109a Regenerator 109b Condenser 110a Absorber 110b Evaporator 111 Circulation path 114 Concentrated side circulation pump (circulation pump) 115 Dilution side circulation pump (circulation pump) 116 Connecting Pipe 118, 218 Dilution refrigerant inlet passage 118b, 218b Branch inlet 118c Dilution flow control valve 119 Control Unit Ab Absorbent Re Refrigerant Vac Refrigerant Vapor

Claims

1. an evaporator that cools a fluid by evaporating a refrigerant; an absorber that absorbs the refrigerant vapor that is the refrigerant evaporated in the evaporator; a regenerator that heats the absorbing liquid that has absorbed the refrigerant vapor in the absorber to separate the absorbing liquid into the refrigerant vapor and the absorbing liquid, thereby regenerating the absorbing liquid; a condenser having a higher pressure than the evaporator and condensing the refrigerant vapor separated in the regenerator; a circulation path for flowing the absorbing liquid separated in the regenerator to the absorber and returning the absorbing liquid that has absorbed the refrigerant vapor in the absorber to the regenerator to circulate the absorbing liquid; a dilution refrigerant inflow passage connected to the circulation passage, for diluting the absorption liquid in the circulation passage by causing the refrigerant in the condenser to flow into the circulation passage.

2. A circulation pump is provided in the circulation path to circulate the absorption liquid, 2. The absorption chiller according to claim 1, wherein the dilution refrigerant inflow passage is connected to a position upstream of the circulation pump in the circulation passage to allow the refrigerant for dilution to flow therein.

3. A connecting pipe connecting the condenser and the evaporator is further provided.

2. The absorption chiller according to claim 1, wherein the dilution refrigerant inflow passage includes a branch inflow passage branching from the connecting pipe and connected to the circulation passage, for allowing the dilution refrigerant to flow in.

4. A dilution flow rate control valve is provided in the dilution refrigerant inflow passage to adjust the amount of the refrigerant flowing from the condenser into the circulation passage, 2. The absorption chiller according to claim 1, further comprising a control unit that adjusts an amount of the refrigerant caused to flow into the circulation path by the dilution flow control valve, each time the chiller is stopped and when the chiller is in operation, based on a concentration of the absorption liquid in the circulation path.

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