JP6790566B2 - Absorption heat pump device - Google Patents

Description

The present invention relates to an absorption heat pump device.

Conventionally, an absorption heat pump device using an absorbing liquid capable of absorbing vapor at the time of evaporation of a refrigerant is known (see, for example, Patent Document 1).

The above-mentioned Patent Document 1 includes a regenerator that heats an absorption liquid by utilizing the heat of the exhaust gas of an engine, a condenser, an evaporator, and an absorber, and can perform air conditioning in a vehicle. The configured vehicle absorption heat pump device is disclosed. The vehicle-mounted absorption heat pump device described in Patent Document 1 is provided with a dilution passage capable of communicating the condenser and the absorber under predetermined conditions. Then, in order to prevent the absorption liquid from crystallizing (solidifying) while the air conditioning operation is stopped, the refrigerant (water) in the condenser is supplied to the absorber via the dilution passage to dilute the absorption liquid. It is configured as follows. The absorption liquid dilution operation is performed each time the engine is stopped, the heat pump device itself is stopped, and the occupant requests to stop the air conditioning operation.

Japanese Patent No. 5708998

However, in the vehicle-mounted absorption heat pump device described in Patent Document 1, every time the air conditioning operation is stopped, the absorption liquid is diluted to prevent the absorption liquid from crystallizing. Therefore, the next air conditioning operation is performed. After resumption, it is considered that there will be a certain time delay before the diluted absorption liquid is concentrated in the regenerator and the entire absorption heat pump device starts to function (air conditioning becomes effective). Further, if the operation of stopping the air conditioning operation is repeated for some reason before the air conditioning function is exhibited, a situation may occur in which the air conditioning function cannot be appropriately provided to the occupants in the vehicle. Therefore, it is desired that the occupants quickly exert the air-conditioning function even under the air-conditioning operation condition in a short time.

The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to prevent the absorption liquid from crystallizing (solidifying) when the air conditioning operation is stopped, and to frequently perform the invention. It is an object of the present invention to provide an absorption heat pump device capable of quickly exerting an air conditioning function even in a situation where operation and operation stop occur.

In order to achieve the above object, the absorption heat pump device according to one aspect of the present invention includes a gas-liquid separation unit that separates refrigerant vapor from the absorption liquid heated by the heating unit, and a refrigerant separated by the gas-liquid separation unit. The heat of the condenser that condenses the steam, the absorber that allows the absorber to absorb the refrigerant, and the absorber that flows from the gas-liquid separation section to the absorber is applied to the absorber that flows from the absorber to the heating section. It is provided with a liquid-liquid heat exchanger and an absorption liquid dilution passage connected to a portion upstream of the liquid-liquid heat exchanger, and the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is high. When it is larger than the first threshold value, in order to prevent the absorption liquid from crystallizing, the refrigerant of the condenser supplied through the absorption liquid dilution passage is used as the absorption liquid on the upstream side of the liquid-liquid heat exchanger. It is configured to dilute the absorption liquid by mixing with.

The absorption heat pump device according to one aspect of the present invention crystallizes the absorption liquid when the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is higher than the first threshold value as described above. To prevent this, the refrigerant of the condenser is mixed with the absorption liquid to dilute the absorption liquid. As a result, the absorption liquid is diluted only when the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is higher than the first threshold value, so that every time the operation of the absorption heat pump device is stopped, the absorption liquid is diluted. Unlike the case where the absorption liquid is diluted for the purpose of preventing crystallization, it is possible to prevent the absorption liquid from being diluted more than necessary. That is, even when the operation of the absorption heat pump device is temporarily stopped, if the concentration of the absorption liquid is equal to or less than the first threshold value, the absorption liquid can not be diluted. Therefore, when the absorption heat pump device resumes operation, the undiluted absorption liquid can be concentrated in a short time, and the time until the absorption heat pump device functions can be shortened. Further, when the concentration of the absorbing liquid is higher than the first threshold value when the air conditioning operation is stopped, the crystallization of the absorbing liquid when the air conditioning operation is stopped can be effectively prevented by diluting the absorbing liquid. As a result, while preventing crystallization (solid phase) of the absorbing liquid when the air conditioning operation is stopped, the air conditioning function can be quickly exerted even in a situation where frequent operation and operation stop occur.

In the absorption heat pump device according to the above one aspect, preferably, the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is larger than the first threshold value, and the gas-liquid separation unit supplies the absorption liquid to the absorber. When the temperature of the absorbed liquid is smaller than the second threshold value, the refrigerant of the condenser is mixed with the absorbed liquid to dilute the absorbed liquid.

With this configuration, in addition to the concentration of the absorbent liquid supplied from the gas-liquid separator to the absorber, the temperature of the absorbent liquid supplied from the gas-liquid separator to the absorber is also taken into consideration to dilute the absorbent liquid. Therefore, the diluting operation of the absorbing solution can be limited to the minimum necessary number of times (frequency). Therefore, the absorption liquid (concentrated liquid) that does not need to be diluted can be used to reliably maintain the state (standby state) for quickly starting the operation of the absorption heat pump device.

In the absorption heat pump device according to the above one aspect, preferably, by sequentially connecting the heating unit, the gas-liquid separation unit, and the absorber, a circulation passage through which the absorption liquid can be circulated is further provided , and the absorption liquid is diluted. The passage allows the refrigerant of the condenser to be between the outlet of the gas-liquid separator and the inlet of the absorber when the concentration of the absorbent liquid supplied from the gas-liquid separator to the absorber is higher than the first threshold value. liquid circulation path - that is organized as than the liquid heat exchanger is supplied to the portion or gas-liquid separator on the upstream side to dilute the absorbent solution.

With this configuration, when the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is higher than the first threshold value, the absorption liquid is crystallized (solid phase) via the absorption liquid dilution passage. It can be reliably supplied to the place where crystallization is most likely to occur (the part of the circulation passage between the outlet of the gas-liquid separation part and the inlet of the absorber, or the inside of the gas-liquid separation part). As a result, crystallization (solid phase) of the absorbing liquid when the air conditioning operation is stopped can be effectively prevented.

In the absorption heat pump apparatus according to the above one aspect, preferably, the concentration of the absorption liquid is acquired based on the temperature in the gas-liquid separation section and the pressure of the atmosphere in which the absorption liquid is concentrated with the separation of the refrigerant vapor. When the concentration of the absorption liquid is higher than the first threshold value, the refrigerant of the condenser is mixed with the absorption liquid to dilute the absorption liquid.

With this configuration, the maximum concentration of the absorption liquid (concentrated liquid) supplied from the gas-liquid separation unit to the absorber is based on the temperature inside the gas-liquid separation unit and the pressure of the atmosphere in which the absorption liquid is concentrated. Can be easily grasped. Then, since the absorption liquid can be diluted by comparing the maximum value of the concentration of the concentrated liquid with the first threshold value, crystallization (solidification) of the absorption liquid can be reliably prevented.

In the absorption heat pump device according to the above one aspect, preferably, when the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is larger than the first threshold value at least when the cooling operation is stopped, the condenser It is configured to mix the refrigerant with the absorption liquid to dilute the absorption liquid.

With this configuration, even when the cooling operation is stopped, the absorption liquid is diluted only when the concentration of the absorption liquid stored in the gas-liquid separation section is higher than the first threshold value, so that absorption is possible. It is possible to prevent the liquid from being diluted more than necessary.

The following configuration is also conceivable in the absorption heat pump device according to the above one aspect.

(Appendix 1)
That is, in the absorption type heat pump device in which the concentration of the absorption liquid is obtained based on the temperature in the gas-liquid separation part and the pressure of the atmosphere in which the absorption liquid is concentrated due to the separation of the refrigerant vapor, the temperature in the gas-liquid separation part is set. A first temperature sensor to detect and a pressure sensor to detect the saturated vapor pressure in the gas-liquid separation unit are further provided, and the temperature in the gas-liquid separation unit detected by the first temperature sensor and the air detected by the pressure sensor are provided. It is configured so that the concentration of the absorbing liquid is obtained based on the pressure in the liquid separating portion.

(Appendix 2)
Further, in the absorption heat pump device further including the first temperature sensor and the pressure sensor, a second temperature sensor for detecting the temperature of the absorption liquid supplied from the gas-liquid separation unit to the absorber is further provided, and the concentration of the absorption liquid is further provided. Is larger than the first threshold value and the temperature of the absorbing liquid detected by the second temperature sensor is smaller than the second threshold value, the refrigerant of the condenser is mixed with the absorbing liquid to prepare the absorbing liquid. It is configured to be diluted.

(Appendix 3)
Further, in the absorption heat pump device further equipped with the second temperature sensor, the heat of the absorption liquid flowing through the circulation passage from the gas-liquid separation unit to the absorber is transferred from the absorber to the heating unit during the cooling operation. Heat exchange for lowering the temperature of the absorbing liquid flowing from the gas-liquid separation part to the absorber and raising the temperature of the absorbing liquid flowing from the absorber to the heating part by applying the above to the absorbing liquid. Further provided with a device, the second temperature sensor is configured to detect the temperature of the absorbent liquid flowing between the outlet of the heat exchanger and the inlet of the absorber.

(Appendix 4)
Further, in the absorption heat pump device that dilutes the absorption liquid at least when the cooling operation is stopped, the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber during the cooling operation is the first threshold in addition to the time when the cooling operation is stopped. When it is larger than the value, the refrigerant of the condenser is mixed with the absorption liquid to dilute the absorption liquid.

(Appendix 5)
Further, in the absorption heat pump device further provided with the absorption liquid dilution passage, the concentration of the absorption liquid provided in the absorption liquid dilution passage and supplied from the gas-liquid separation unit to the absorber is larger than the first threshold value. In some cases, a control valve that opens when the refrigerant of the condenser is mixed with the absorption liquid to dilute the absorption liquid is further provided.

(Appendix 6)
Further, in the absorption heat pump device in which the concentration of the absorption liquid is acquired based on the temperature in the gas-liquid separation section and the pressure of the atmosphere in which the absorption liquid is concentrated, the absorption liquid is separated by the temperature of the absorption liquid and the refrigerant vapor. Further provided is a table in which the concentration of the absorbent liquid is associated with the pressure of the atmosphere in which the is concentrated, and based on the above table, when the concentration of the absorbent liquid is higher than the first threshold value, the condenser The refrigerant is mixed with the absorption liquid to dilute the absorption liquid.

It is a figure which showed the whole structure of the absorption type heat pump apparatus in 1st Embodiment of this invention. FIG. 5 is a diagram for obtaining a concentration from the temperature-pressure relationship of an aqueous solution of lithium bromide (LiBr) referred to during operation of the absorption heat pump device according to the first embodiment of the present invention. It is a figure which showed the correlation between the concentration of the lithium bromide (LiBr) aqueous solution and the crystal temperature referred to at the time of operation of the absorption heat pump apparatus in 1st Embodiment of this invention. It is a figure which showed the whole structure of the absorption type heat pump apparatus in the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
First, the configuration of the absorption heat pump device 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

In the absorption heat pump device 100 according to the first embodiment of the present invention, a refrigerant (water) and an absorption liquid (lithium bromide (LiBr) aqueous solution) are used. Further, the absorption heat pump device 100 is mounted on a vehicle (not shown) and is configured to be applied to in-vehicle air conditioning. Further, the absorption heat pump device 100 is configured to use (recover) the heat of the high-temperature exhaust gas discharged from the engine 90 to heat the absorption liquid (dilute liquid).

(Structure of absorption heat pump device)
As shown in FIG. 1, the absorption heat pump device 100 includes a regenerator 10 (inside the two-point chain line frame), a condenser 20, an evaporator 30, an absorber 40, a liquid-liquid heat exchanger 50, and the like. An absorption liquid passage 51 (an example of a circulation passage) and a refrigerant passage 52 connecting them are provided. Here, the absorption liquid passage 51 sequentially connects the heating unit 11, the gas-liquid separation unit 12, and the absorber 40.

That is, the absorption liquid passage 51 includes a path 51a connecting the heating unit 11 and the gas-liquid separation unit 12, a path 51b connecting the gas-liquid separation unit 12 and the absorber 40, and the absorber 40 and the heating unit 11. Includes a path 51c and the like. Further, the refrigerant passage 52 connects the path 52a connecting the gas-liquid separation unit 12 and the condenser 20, the path 52b connecting the condenser 20 and the evaporator 30, and the evaporator 30 and the absorber 40. Includes path 52c.

The regenerator 10 is composed of a heating unit 11 and a gas-liquid separation unit 12. The heating unit 11 is a plate heat exchanger, and has a role of heating the diluted absorption liquid (dilute liquid) by absorbing the refrigerant (water) in the LiBr aqueous solution (concentrated liquid). Specifically, in the heating unit 11, the high-temperature (about 300 ° C. to about 400 ° C.) exhaust gas connected to the engine 90 and flowing through the exhaust pipe 91 and the absorbing liquid (rare liquid) flowing through the path 51c are heated. It is configured to be replaced. The exhaust pipe 91 includes an exhaust heat supply path 91a that passes through the heating unit 11 and a detour 91b that does not pass through the heating unit 11, and a valve 92 is provided in the exhaust heat supply path 91a.

By opening the valve 92 during the cooling operation, the exhaust gas from the engine 90 is circulated to the heating unit 11 via the exhaust heat supply path 91a. Further, the gas-liquid separation unit 12 has a function of separating the refrigerant vapor (high temperature steam) from the absorption liquid heated by the heating unit 11 and supplied via the path 51a. Therefore, the gas-liquid separation unit 12 stores the absorbing liquid (concentrated liquid) after the refrigerant vapor is separated.

The condenser 20 has a role of condensing and liquefying the refrigerant vapor separated by the gas-liquid separation unit 12 and supplied through the path 52a. Specifically, the heat exchange unit 83 is provided inside the condenser 20, and the high-temperature steam is directly exposed to the outer surface of the heat exchange unit 83. Further, cooling water is circulated inside the heat exchange unit 83. As a result, the refrigerant vapor is cooled by the cooling water to become condensed water, while the cooling water obtains heat of condensation and is warmed. Further, the refrigerant storage portion 20a of the condenser 20 is configured to store a predetermined amount of condensed water (liquid refrigerant).

The evaporator 30 is kept in a vacuum state (absolute pressure of 1 kPa or less), and the condensed water (liquid refrigerant) supplied via the path 52b is evaporated (vaporized) under the conditions of low temperature and low pressure (vacuum state). Has a role. Specifically, inside the evaporator 30, a refrigerant storage unit 30a for storing condensed water and a heat exchange unit 31 are provided. Then, the condensed water pumped from the refrigerant storage unit 30a by the pump 32 is injected by the injector 33 onto the outer surface of the heat exchange unit 31. In addition, circulating water for air conditioning is circulated inside the heat exchange unit 31. As a result, the liquid refrigerant evaporates while obtaining latent heat of vaporization to become refrigerant vapor (low temperature steam), while the circulating water is deprived of heat and cooled. The circulating water may be water or coolant (antifreeze).

Further, the heat exchange unit 31 is connected to the heat exchange unit 86 for in-vehicle air conditioning via the circulating water circuit 85 outside the evaporator 30. The circulating water circuit 85 is provided with a liquid feed pump 87. As a result, in the vehicle interior air conditioning heat exchange unit 86, the air inside the vehicle blown by the blower fan 88 is cooled by the circulating water flowing through the vehicle interior air conditioning heat exchange unit 86. Then, the cooled air (cold air) is configured to be blown out into the vehicle interior space 95 (inside the alternate long and short dash line frame).

The absorber 40 is kept in a vacuum state (absolute pressure of 1 kPa or less), and is evaporated (vaporized) by the evaporator 30 to the absorbent liquid (concentrated liquid) supplied from the gas-liquid separation unit 12 via the path 51b. At the same time, it has a role of absorbing the refrigerant vapor (low temperature steam) sucked through the path 52c. Specifically, a heat exchange unit 41 is provided inside the absorber 40, and the absorbent liquid (concentrated liquid) pumped up by the pump 42 is directly exposed to the outer surface of the heat exchange unit 41 by the injector 43. In this state, the refrigerant (low temperature water vapor) is absorbed by the absorbing liquid. Further, cooling water is circulated inside the heat exchange unit 41. As a result, the absorbing liquid (dilute liquid) in which the refrigerant is absorbed is cooled by the cooling water, while the cooling water obtains the absorbed heat and is warmed. Then, the absorbent liquid (dilute liquid) is stored in the absorber 40. The path 51c is provided with a liquid feed pump 55 that sucks the dilute liquid stored in the absorbent liquid storage unit 40a of the absorber 40 and supplies it to the heating unit 11.

The liquid-liquid heat exchanger 50 has a role of exchanging heat between the absorbing liquid (concentrated liquid) flowing through the path 51b and the absorbing liquid (dilute liquid) flowing through the path 51c. The liquid-liquid heat exchanger 50 is a plate-type heat exchanger. In the liquid-liquid heat exchanger 50, the heat of the concentrated liquid flowing from the gas-liquid separation unit 12 toward the absorber 40 is transferred from the absorber 40 to the heating unit. It is applied to the dilute liquid flowing toward 11. As a result, the temperature of the concentrated liquid flowing from the gas-liquid separation unit 12 to the absorber 40 is lowered, and the temperature of the dilute liquid flowing from the absorber 40 to the heating unit 11 is raised.

Further, the absorption heat pump device 100 includes a cooling water circuit 80 that is driven during the cooling operation. The cooling water circuit 80 is used for cooling the high-temperature steam in the condenser 20 and cooling (removing heat) the absorbed heat generated when the low-temperature steam is absorbed in the absorbing liquid (concentrated liquid) in the absorber 40. Specifically, the cooling water circuit 80 includes a cooling water circulation path 81 through which cooling water flows, a pump 82, a heat exchange unit 83 arranged in the condenser 20, and a heat exchange unit 41 arranged in the absorber 40. , And a heat radiating unit 84. In the heat radiating unit 84, the cooling water flowing through the heat exchange unit 84a is cooled (heat radiated) by the air (outside air) blown by the blower 84b.

Based on the configuration described above, the absorption heat pump device 100 is operated as follows.

That is, as shown in FIG. 1, the absorbing liquid (dilute liquid) is heated by the exhaust gas from the engine 90 in the heating unit 11. The heated absorption liquid is separated into a LiBr concentrated liquid and a refrigerant (high temperature steam) in the gas-liquid separation unit 12. The refrigerant is liquefied in the condenser 20 and then guided to the evaporator 30. Cold water (circulating water for air conditioning) is generated by evaporating the refrigerant (condensed water) in the evaporator 30. Then, the refrigerant (low temperature steam) evaporated in the evaporator 30 is guided to the absorber 40.

On the other hand, the LiBr concentrated liquid (absorbent liquid) separated by the gas-liquid separation unit 12 is guided to the absorber 40 via the liquid-liquid heat exchanger 50. Then, the absorber 40 absorbs the refrigerant (low temperature water vapor) with respect to the LiBr concentrated liquid (absorbing liquid) to generate a dilute liquid (absorbing liquid). The dilute liquid is sent to the heating unit 11 again. Therefore, the refrigerant is circulated in the direction of arrow P1 and the absorbing liquid is circulated in the direction of arrow P2.

Here, the absorption heat pump device 100 is configured to perform an operation of diluting the absorption liquid (concentrated liquid) supplied to the absorber 40 according to the operating condition.

Specifically, the absorption heat pump device 100 is provided with an absorption liquid dilution passage 61 that connects the condenser 20 and the path 51b. The absorption liquid dilution passage 61 connects the refrigerant storage portion 20a located at the bottom of the condenser 20 and the portion of the path 51b between the outlet 12a of the gas-liquid separation portion 12 and the inlet 40b of the absorber 40. ing. Further, the absorption liquid dilution passage 61 is provided with a valve 62 (an example of a control valve) and a liquid feed pump 63. The valve 62 is a solenoid valve and is normally closed.

Then, in the first embodiment, when the concentration ξ of the absorbing liquid (LiBr concentrated liquid) supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α (an example of the first threshold value). The valve 62 is opened and the liquid feed pump 63 is started in order to prevent the absorption liquid from crystallizing. Then, the refrigerant of the condenser 20 (refrigerant storage unit 20a) is mixed with the absorption liquid flowing in the path 51b via the absorption liquid dilution passage 61. As a result, the absorption liquid flowing through the path 51b is configured to be diluted to a predetermined concentration or less. Further, in this dilution operation, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α, the refrigerant of the condenser 20 is absorbed as the absorbing liquid (LiBr concentrated liquid). It is configured to dilute the absorbent by mixing with.

Here, the concentration ξ of the absorption liquid is configured to be acquired based on the temperature in the gas-liquid separation unit 12 and the pressure of the atmosphere in which the absorption liquid is concentrated with the separation of the refrigerant vapor. In this case, the absorption type heat pump device 100 includes a temperature sensor 71 (an example of a first temperature sensor) that detects the temperature inside the gas-liquid separation unit 12, and a pressure sensor that detects the saturated vapor pressure inside the gas-liquid separation unit 12. 72 is provided in the gas-liquid separation unit 12.

Further, in the absorption heat pump device 100, the concentration diagram of the lithium bromide aqueous solution as shown in FIG. 2 becomes a table (numerical table) in the storage unit (memory) in the operation control device (not shown). It is stored in advance. For example, when the saturated vapor pressure in the gas-liquid separation unit 12 is about 50 mmHg and the temperature is about 55 ° C., the concentration ξ (weight percent) of the lithium bromide aqueous solution is about 45 wt% in FIG. 2 (FIG. 2). Is determined from the table). Therefore, based on the temperature in the gas-liquid separation unit 12 detected by the temperature sensor 71 (see FIG. 1) and the pressure in the gas-liquid separation unit 12 detected by the pressure sensor 72 (see FIG. 1), the air The concentration ξ of the absorbing liquid (LiBr concentrated liquid) in the liquid separating unit 12 is configured to be grasped (acquired).

Further, in the first embodiment, the concentration ξ of the absorbing liquid is larger than the threshold value α, and the temperature of the absorbing liquid supplied from the gas-liquid separation unit 12 to the absorber 40 (with the liquid-liquid heat exchanger 50). When the temperature of the absorbing liquid flowing through the path 51b with the absorber 40) is smaller than the threshold value β (an example of the second threshold value), the refrigerant of the condenser 20 is mixed with the absorbing liquid and absorbed. It is configured to dilute the liquid. In this case, as shown in FIG. 1, the temperature sensor 73 (an example of the second temperature sensor) that detects the temperature of the absorbed liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is the liquid-liquid heat exchanger 50. It is provided in the portion of the path 51b between the outlet 50a of the above and the inlet 40b of the absorber 40.

Further, in the absorption heat pump device 100, the correlation (crystal diagram) of the crystal temperature with respect to the concentration ξ (weight percent) of the lithium bromide aqueous solution as shown in FIG. 3 is in the operation control device (not shown). It is stored in advance as a table (numerical table) in the storage unit (memory). For example, when the concentration ξ of the absorbing liquid in the gas-liquid separation unit 12 is about 58 wt% and the temperature in the gas-liquid separation unit 12 is about 10 ° C. or lower, the lithium bromide aqueous solution crystallizes (solid). It is determined from FIG. 3 (a table in which FIG. 3 is numerically tabulated) that the state is to be phased.

Therefore, the concentration ξ (threshold value α) of the absorbed liquid in the gas-liquid separation unit 12 and the temperature of the absorbed liquid detected by the temperature sensor 73 (see FIG. 1) (the outlet 50a of the liquid-liquid heat exchanger 50 and absorption). Based on the temperature of the absorbing liquid flowing through the path 51b between the inlet 40b of the vessel 40 (threshold value β)), the refrigerant of the condenser 20 is mixed with the absorbing liquid to dilute the absorbing liquid. Has been done. The reason why the temperature sensor 73 is provided in the portion of the path 51b between the outlet 50a of the liquid-liquid heat exchanger 50 and the inlet 40b of the absorber 40 is as follows.

That is, when the gas-liquid separation unit 12 circulates through the path 51b in a state where the concentration ξ of the absorbed liquid is larger than the threshold value α, the absorbed liquid is cooled by the liquid-liquid heat exchanger 50. Therefore, the absorbing liquid (concentrated liquid) flowing through the path 51b between the liquid-liquid heat exchanger 50 and the absorber 40 tends to crystallize most easily (the temperature tends to be the lowest). For this reason, it is most desirable to determine whether or not to perform the absorption liquid dilution operation based on the temperature of the absorption liquid detected by the temperature sensor 73. Further, in order to effectively dilute the concentrated liquid flowing through the path 51b between the liquid-liquid heat exchanger 50 and the absorber 40, the absorption liquid dilution passage 61 is connected to the outlet 12a of the gas-liquid separation unit 12. It is connected to the portion of the path 51b between the liquid-liquid heat exchanger 50 and the inlet 50b.

Further, in the first embodiment, the above-mentioned dilution operation is performed when the cooling operation is stopped. As a result, even when the absorption heat pump device 100 is stopped, the absorption liquid in the absorber 40 is prevented from crystallizing (solidifying). Further, in addition to when the cooling operation is stopped, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α during the cooling operation, the refrigerant of the condenser 20 is absorbed. It is configured to mix with the liquid to dilute the absorption liquid. As a result, the concentration of the absorbing liquid is adjusted to an appropriate range even during normal operation.

(Effect of the first embodiment)
In the first embodiment, the following effects can be obtained.

In the first embodiment, as described above, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α, in order to prevent crystallization of the absorbing liquid, The refrigerant of the condenser 20 is mixed with the absorption liquid (LiBr concentrated liquid) to dilute the absorption liquid. As a result, the absorption liquid is diluted only when the concentration ξ of the absorption liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α, so that the operation of the absorption heat pump device 100 is stopped. Unlike the case where the absorption liquid is diluted for the purpose of preventing crystallization each time, it is possible to prevent the absorption liquid from being diluted more than necessary. That is, even when the operation of the absorption heat pump device 100 is temporarily stopped, if the concentration ξ of the absorption liquid is equal to or less than the threshold value α, the absorption liquid can not be diluted. Therefore, when the absorption heat pump device 100 resumes operation, the time until the absorption heat pump device 100 functions can be shortened by the amount that the undiluted absorption liquid can be concentrated in a short time.

In addition to the above effects, when the concentration ξ of the absorption liquid is larger than the threshold value α when the air conditioning operation is stopped, the absorption liquid is diluted to effectively prevent the absorption liquid from crystallizing when the air conditioning operation is stopped. be able to. As a result, while preventing crystallization (solid phase) of the absorbing liquid when the air conditioning operation is stopped, the air conditioning function can be quickly exerted even in a situation where frequent operation and operation stop occur.

Further, in the first embodiment, the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α, and the gas-liquid separating unit 12 supplies the absorbing liquid to the absorber 40. When the temperature of the absorbing liquid is smaller than the threshold value β, the refrigerant of the condenser 20 is mixed with the absorbing liquid (LiBr concentrated liquid) to dilute the absorbing liquid. As a result, in addition to the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40, the temperature of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is also taken into consideration, and the absorbing liquid of the absorbing liquid Since the dilution can be performed, the dilution operation of the absorbing solution can be limited to the minimum necessary number of times (frequency). Therefore, the absorption liquid (concentrated liquid) that does not need to be diluted can be used to reliably maintain the state (standby state) for quickly starting the operation of the absorption heat pump device 100.

Further, in the first embodiment, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α, the refrigerant of the condenser 20 is discharged from the gas-liquid separating unit 12. An absorption liquid dilution passage 61 for supplying the passage 51b between the 12a and the inlet 40b of the absorber 40 to dilute the absorption liquid is provided. As a result, when the concentration ξ of the absorption liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α, the absorption liquid (LiBr concentrated liquid) is crystallized through the absorption liquid dilution passage 61. It can be reliably supplied to the portion where crystallization (solidification) is most likely to occur (the portion of the absorption liquid passage 51 between the outlet 12a of the gas-liquid separation portion 12 and the inlet 40b of the absorber 40). As a result, crystallization (solid phase) of the absorbing liquid when the air conditioning operation is stopped can be effectively prevented.

Further, in the first embodiment, the concentration ξ of the absorption liquid is configured to be acquired based on the temperature in the gas-liquid separation unit 12 and the pressure of the atmosphere in which the absorption liquid is concentrated with the separation of the refrigerant vapor. When the concentration ξ of the absorbing liquid is larger than the threshold value α, the refrigerant of the condenser 20 is mixed with the absorbing liquid to dilute the absorbing liquid. As a result, the concentration ξ of the absorption liquid (concentrated liquid) supplied from the gas-liquid separation unit 12 to the absorber 40 is maximized based on the temperature in the gas-liquid separation unit 12 and the pressure of the atmosphere in which the absorption liquid is concentrated. The value can be easily grasped. Then, since the absorption liquid can be diluted by comparing the maximum value of the concentration ξ of the concentrated liquid with the threshold value α, crystallization (solidification) of the absorption liquid can be reliably prevented.

Further, in the first embodiment, the refrigerant of the condenser 20 is absorbed when the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α at least when the cooling operation is stopped. It is configured to be mixed with the liquid to dilute the absorption liquid. As a result, even when the cooling operation is stopped, the absorption liquid is diluted only when the concentration ξ of the absorption liquid stored in the gas-liquid separation unit 12 is larger than the threshold value α, so that the absorption liquid is required. It is possible to suppress the dilution as described above.

Further, in the first embodiment, a temperature sensor 71 for detecting the temperature in the gas-liquid separation unit 12 and a pressure sensor 72 for detecting the saturated vapor pressure in the gas-liquid separation unit 12 are provided. Then, the concentration ξ of the absorbing liquid is acquired based on the temperature in the gas-liquid separation unit 12 detected by the temperature sensor 71 and the pressure in the gas-liquid separation unit 12 detected by the pressure sensor 72. As a result, unlike the case where the concentration ξ sensor for detecting the concentration ξ of the absorption liquid is provided exclusively, the temperature sensor 71 and the pressure sensor 72 used for the operation control of the normal absorption heat pump device 100 are effectively used. The concentration ξ of the absorption liquid can be easily grasped (calculated).

Further, in the first embodiment, the temperature sensor 73 for detecting the temperature of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is provided. Then, when the concentration ξ of the absorbing liquid is larger than the threshold value α and the temperature of the absorbing liquid detected by the temperature sensor 73 is smaller than the threshold value β, the refrigerant of the condenser 20 is mixed with the absorbing liquid. To dilute the absorbent solution. As a result, the temperature sensor 73 can detect the temperature of the absorbed liquid at the location where the temperature tends to be the lowest in the path between the gas-liquid separation unit 12 and the absorber 40, and thus absorbs from the gas-liquid separation unit 12. It is possible to reliably grasp the situation in which the absorption liquid (concentrated liquid) supplied to the vessel 40 is likely to crystallize (solidify). Therefore, since the absorption liquid can be diluted under such a situation, crystallization (solid phase) of the absorption liquid can be reliably prevented.

Further, in the first embodiment, during the cooling operation, the heat of the absorbing liquid flowing through the path 51b from the gas-liquid separation unit 12 toward the absorber 40 is transferred to the absorbing liquid flowing through the path 51c from the absorber 40 toward the heating unit 11. A liquid for lowering the temperature of the absorbing liquid flowing from the gas-liquid separation unit 12 toward the absorber 40 and raising the temperature of the absorbing liquid flowing from the absorber 40 toward the heating unit 11- A liquid heat exchanger 50 is provided. Then, the temperature sensor 73 is configured to detect the temperature of the absorbing liquid flowing through the portion of the path 51b between the outlet 50a of the liquid-liquid heat exchanger 50 and the inlet 40b of the absorber 40. As a result, the absorbing liquid (LiBr concentrated liquid) flowing through the portion of the path 51b between the outlet 50a of the liquid-liquid heat exchanger 50 and the inlet 40b of the absorber 40 is most likely to crystallize (the temperature tends to be the lowest). ) Because of the tendency, the diluting operation of the absorbing liquid can be effectively performed by using the temperature of the absorbing liquid in this portion as an index.

Further, in the first embodiment, in addition to when the cooling operation is stopped, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α during the cooling operation, the condenser The 20 refrigerants are mixed with the absorbing liquid to dilute the absorbing liquid. As a result, even when the absorption liquid is concentrated more than necessary in the gas-liquid separation unit 12 during normal cooling operation and the possibility of crystallization (solid phase) is increased, the concentration of the absorption liquid (concentrated liquid) is increased. The absorption solution can be diluted when ξ is larger than the threshold value α. As a result, both the absorption liquid and the crystallization (solid phase) during the cooling operation are prevented, so that the absorption heat pump device 100 can be operated stably.

Further, in the first embodiment, the condenser 20 is provided in the absorption liquid dilution passage 61 and the concentration ξ of the absorption liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α. The valve 62 is provided when the refrigerant of the above is mixed with the absorption liquid to dilute the absorption liquid. As a result, by interlocking the concentration ξ of the absorbing liquid and the opening / closing operation of the valve 62, the refrigerant of the condenser 20 is mixed with the absorbing liquid through the absorbing liquid dilution passage 61, and the absorbing liquid is easily diluted. be able to.

Further, in the first embodiment, the concentration ξ of the absorption liquid is associated with the temperature of the absorption liquid and the pressure of the atmosphere in which the absorption liquid is concentrated with the separation of the refrigerant vapor (pressure in the gas-liquid separation unit 12). The table is provided in the memory in the operation control device of the absorption heat pump device 100. Then, based on this table, when the concentration ξ is larger than the threshold value α, the refrigerant of the condenser 20 is mixed with the absorption liquid to dilute the absorption liquid. As a result, the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 can be easily grasped by referring to the table stored in the memory in the operation control device. The diluting operation of the concentrated solution) can be performed accurately.

[Second Embodiment]
The second embodiment will be described with reference to FIG. In this second embodiment, an example in which the connection destination of the absorption liquid dilution passage 261 is different from that of the first embodiment will be described. In the figure, the same configurations as those in the first embodiment are designated by the same reference numerals.

The absorption heat pump device 200 according to the second embodiment is provided with a passage 261 for diluting the absorption liquid. The absorption liquid dilution passage 261 connects the refrigerant storage portion 20a of the condenser 20 and the inlet 12b of the gas-liquid separation portion 12. Further, the absorption liquid dilution passage 261 is provided with a valve 262 (an example of a control valve) and a liquid feed pump 63. The valve 262 is a solenoid valve and is normally closed.

As a result, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α, the valve 262 is set to prevent crystallization of the absorbing liquid (LiBr concentrated liquid). It is opened and the liquid feed pump 63 is started. Then, the refrigerant of the condenser 20 is directly supplied from the inlet 12b to the gas-liquid separation unit 12 via the absorption liquid dilution passage 261. Also in the absorption heat pump device 200, when the concentration ξ of the absorption liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α, the refrigerant of the condenser 20 is absorbed as the absorption liquid (LiBr concentrated liquid). It is configured so that the absorption liquid is diluted by mixing with. The other configurations of the absorption heat pump device 200 according to the second embodiment are the same as those of the first embodiment.

(Effect of the second embodiment)
In the second embodiment, as described above, when the concentration ξ of the absorbing liquid supplied from the gas-liquid separating unit 12 to the absorber 40 is larger than the threshold value α, the refrigerant of the condenser 20 is used as the gas-liquid separating unit. A passage 261 for diluting the absorption liquid is provided for supplying to 12 to dilute the absorption liquid. As a result, when the concentration ξ of the absorption liquid (LiBr concentrated liquid) supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α, the absorption liquid crystals pass through the absorption liquid dilution passage 61. It can be reliably supplied to a place (inside the gas-liquid separation unit 12) where crystallization (solidification) is likely to occur. As a result, crystallization (solid phase) of the absorbing liquid when the air conditioning operation is stopped can be effectively prevented.

Further, in the second embodiment, the absorption liquid dilution passage 261 is configured so as to connect the refrigerant storage portion 20a of the condenser 20 and the inlet 12b of the gas-liquid separation portion 12. As a result, when the concentration ξ of the absorbing liquid is larger than the threshold value α, the refrigerant of the condenser 20 can be directly supplied to the gas-liquid separation unit 12. That is, unlike the case where the absorption liquid dilution passage 261 is connected to the path 51a between the outlet of the heating unit 11 and the inlet 12b of the gas-liquid separation unit 12, the refrigerant is reliably separated into gas-liquid in the gas-liquid separation unit 12. The refrigerant of the condenser 20 can be supplied to the absorbing liquid after being concentrated. As a result, while the gas-liquid separation unit 12 is functioning effectively, the absorption liquid (concentrated liquid) is used when the concentration ξ of the absorption liquid supplied from the gas-liquid separation unit 12 to the absorber 40 is larger than the threshold value α. It can be reliably diluted. The other effects are the same as those in the first embodiment.

[Modification example]
The embodiments disclosed this time should be considered as exemplary in all respects and not restrictive. The scope of the present invention is shown not by the description of the above embodiment but by the scope of claims, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims.

For example, in the first and second embodiments, the present invention is applied to the absorption heat pump device 100 capable of performing only cooling operation, but the present invention is not limited to this. For example, the present invention may be applied to an absorption heat pump device capable of performing not only cooling operation but also heating operation. During the heating operation, the high-temperature refrigerant vapor separated by the gas-liquid separation unit 12 is supplied to the evaporator 30 to transfer heat to the circulating water for air conditioning via the heat exchange unit 31. Then, the refrigerant (water) condensed by the evaporator 30 is returned to the path 51c on the upstream side of the heating unit 11. As described above, the present invention may be applied to an absorption heat pump device capable of both cooling operation and heating operation.

Further, in the second embodiment, the refrigerant of the condenser 20 is directly supplied to the gas-liquid separation unit 12 via the absorption liquid dilution passage 261, but the present invention is not limited to this. For example, the absorption liquid dilution passage 261 may be connected to the portion of the path 51a between the outlet of the heating unit 11 and the inlet 12b of the gas-liquid separation unit 12.

Further, in the first and second embodiments, the temperature sensor 71 and the pressure sensor 72 are provided inside the gas-liquid separation unit 12 so as to grasp (calculate) the concentration ξ of the absorbed liquid. Not limited to this. For example, a densitometer is provided inside the gas-liquid separation unit 12, and the refrigerant of the condenser 20 is mixed with the absorbent liquid based on the concentration ξ of the absorbent liquid measured by the densitometer to dilute the absorbent liquid. It may be configured.

Further, in the first and second embodiments, the absorption liquid is heated by utilizing the heat of the exhaust gas of the engine 90, but the present invention is not limited to this. The absorption heat pump device of the present invention may be applied for air conditioning of a hybrid vehicle or an electric vehicle using an electric motor. The present invention may be applied to the air conditioning of a passenger vehicle equipped with a fuel cell system by utilizing the exhaust heat of a battery or motor of an electric vehicle or the exhaust heat of a fuel cell during power generation as a heat source for heating the absorption liquid.

10 Regenerator 11 Heating unit 12 Gas-liquid separation unit 12a Outlet 12b Inlet 20 Condenser 30 Evaporator 40 Absorber 40b Inlet 50 Liquid-liquid heat exchanger 50a Outlet 50b Inlet 51 Absorbent passage (circulation passage)
51b path (the part of the circulation passage between the outlet of the gas-liquid separation part and the inlet of the absorber)
61, 261 Absorption liquid dilution passage 62, 262 Valve (control valve)
71 Temperature sensor (1st temperature sensor)
72 Pressure sensor 73 Temperature sensor (second temperature sensor)
100, 200 Absorption heat pump device α threshold (first threshold)
β threshold (second threshold)
ξ Concentration (concentration of absorbent)

Claims (5)

A gas-liquid separator that separates the refrigerant vapor from the absorption liquid heated by the heating unit,
A condenser that condenses the refrigerant vapor separated by the gas-liquid separation unit, and
An absorber that absorbs the refrigerant into the absorbent liquid,
A liquid-liquid heat exchanger in which the heat of the absorbing liquid flowing from the gas-liquid separation unit toward the absorber is applied to the absorbing liquid flowing from the absorber toward the heating unit.
It is provided with an absorption liquid dilution passage connected to a portion upstream of the liquid-liquid heat exchanger.
When the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is higher than the first threshold value, the absorption liquid is supplied through the absorption liquid dilution passage in order to prevent the absorption liquid from crystallizing. An absorption heat pump device configured to dilute the absorption liquid by mixing the refrigerant of the condenser with the absorption liquid on the upstream side of the liquid-liquid heat exchanger . The concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is higher than the first threshold value, and the temperature of the absorption liquid supplied from the gas-liquid separation unit to the absorber is the second. The absorption heat pump device according to claim 1, wherein the refrigerant of the condenser is mixed with the absorption liquid to dilute the absorption liquid when the value is smaller than the threshold value. By sequentially connecting the heating unit, the gas-liquid separation unit, and the absorber, a circulation passage through which the absorbed liquid can be circulated is further provided .
In the absorption liquid dilution passage, when the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is larger than the first threshold value, the refrigerant of the condenser is used in the gas-liquid separation unit. the liquid of the circulation passage between the inlet of the outlet and the absorber - that is configured to dilute the upstream portion or the absorption liquid is supplied to the gas-liquid separation unit than liquid heat exchanger, The absorption heat pump device according to claim 1 or 2. The concentration of the absorption liquid is configured to be obtained based on the temperature in the gas-liquid separation unit and the pressure of the atmosphere in which the absorption liquid is concentrated with the separation of the refrigerant vapor.
Any one of claims 1 to 3, which is configured to dilute the absorption liquid by mixing the refrigerant of the condenser with the absorption liquid when the concentration of the absorption liquid is larger than the first threshold value. The absorption heat pump device according to item 1. When the concentration of the absorption liquid supplied from the gas-liquid separation unit to the absorber is higher than the first threshold value at least when the cooling operation is stopped, the refrigerant of the condenser is mixed with the absorption liquid to absorb the absorption liquid. The absorption heat pump device according to any one of claims 1 to 4, which is configured to dilute.

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