JP5575519B2 - Absorption refrigerator - Google Patents

Description

  The present invention relates to an absorption refrigerator having a damper in a refrigerant pipe that sends refrigerant from a high-temperature regenerator to a condenser.

  2. Description of the Related Art Conventionally, absorption refrigerating machines that include a high-temperature regenerator, a low-temperature regenerator, a condenser, an evaporator, and an absorber, which are connected to each other by piping to form a circulation path for absorption liquid and refrigerant, are known (for example, , See Patent Document 1). In this absorption refrigeration machine, the high-temperature regenerator and the condenser are connected by a heat transfer pipe that is piped to the absorption liquid reservoir of the low-temperature regenerator and a refrigerant pipe that passes through a refrigerant drain heat recovery unit. The refrigerant vapor heated by the high-temperature regenerator and separated from the absorbing liquid is condensed in the process of flowing through the refrigerant pipe, and becomes a refrigerant liquid. The refrigerant liquid moves in the refrigerant pipe due to the differential pressure between the high-temperature regenerator and the condenser. . In order to reduce the flow rate of the refrigerant flowing through the refrigerant pipe and sufficiently heat the absorption liquid in the low temperature regenerator and the rare absorption liquid from the absorber with the heat of the refrigerant vapor from the high temperature regenerator, On the downstream side of the drain heat recovery unit, flow resistance means such as a flow rate control valve and an orifice for imparting flow resistance are provided.

JP 2003-287315 A

By the way, the absorption chiller is improved in performance (COP: Coefficient of Performance) as the temperature of the cooling water supplied to the absorption chiller (cooling water inlet temperature) decreases. However, if the cooling water inlet temperature is lower than the arbitrary temperature, the pressure difference between the high temperature regenerator and the condenser decreases as the pressure of the high temperature regenerator decreases. If it is provided, the fluidity of the refrigerant decreases. When the fluidity of the refrigerant liquid decreases, the refrigerant liquid accumulates in the vicinity of the low-temperature regenerator of the refrigerant pipe, or a state in which the refrigerant liquid flows back and forth through the low-temperature regenerator in the refrigerant pipe. There is a risk that the heating regeneration will become unstable, and as a result, hunting may occur in which the temperature on the outlet side of the brine supplied to the heat load repeatedly fluctuates up and down.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an absorption refrigerator that can be stably operated even when the temperature of the cooling water is low.

In order to achieve the above object, the present invention comprises a high temperature regenerator, a low temperature regenerator, an evaporator, a condenser, and an absorber, and the high temperature regenerator and the condenser are connected by a refrigerant pipe passing through the low temperature regenerator. In the absorption refrigerator, in which the refrigerant pipe is provided with flow path resistance means for imparting flow path resistance and a bypass pipe for bypassing the flow path resistance means, and the bypass pipe is provided with an open / close valve. A cooling water pipe for sequentially circulating cooling water to the condenser and the condenser, a cooling water temperature sensor for measuring the cooling water inlet temperature on the absorber inlet side of the cooling water pipe, and according to the measurement result of the cooling water temperature sensor Valve control means for controlling the on-off valve, and the valve control means opens the on-off valve when the cooling water inlet temperature measured by the cooling water temperature sensor is equal to or lower than a first temperature. .

The said structure WHEREIN: The said valve control means may open the said on-off valve fully, when the cooling water inlet temperature measured by the said cooling water temperature sensor is below 1st temperature.

In the above configuration, the valve control means may fully close the on-off valve when the coolant inlet temperature measured by the coolant temperature sensor reaches a second temperature higher than the first temperature.

  In the above-described configuration, a heat input amount control valve for controlling the heat input amount of the high-temperature regenerator is provided, and the valve control unit is configured to perform the measurement according to the measurement result of the cooling water temperature sensor and the opening degree of the heat input amount control valve. The on-off valve may be controlled.

  In the above configuration, the refrigerant pipe on the downstream side of the low-temperature regenerator performs heat exchange between the refrigerant flowing through the refrigerant pipe and the rare absorbent flowing through the rare absorbent pipe extending from the absorber. A refrigerant drain heat recovery device is provided, a pressure sensor for detecting the pressure in the high temperature regenerator is provided in the high temperature regenerator, and a refrigerant temperature sensor for measuring the temperature of the refrigerant on the refrigerant drain heat recovery device outlet side of the refrigerant pipe The valve control means may control the on-off valve according to a measurement result of the cooling water temperature sensor, a detection result of the pressure sensor, and a measurement result of the refrigerant temperature sensor.

  According to the present invention, the cooling water pipe for sequentially circulating the cooling water to the absorber and the condenser is provided, the cooling water temperature sensor for measuring the temperature of the cooling water is provided on the absorber inlet side of the cooling water pipe, and the cooling water temperature sensor Since the valve control means for controlling the on-off valve according to the measurement result is provided, for example, when the coolant temperature is low, the on-off valve is controlled so as to increase the amount of refrigerant flowing through the bypass pipe. Therefore, the absorption refrigerator can be operated stably.

It is a schematic block diagram of the absorption refrigerator which concerns on the 1st Embodiment of this invention. It is a figure explaining control of an on-off valve. It is a schematic block diagram of the absorption refrigerator which concerns on the 3rd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic configuration diagram of an absorption refrigerator according to the first embodiment.
The absorption refrigerator 100 is a double-effect absorption refrigerator that uses water as a refrigerant and a lithium bromide (LiBr) aqueous solution as an absorption liquid. As shown in FIG. 1, the absorption refrigerator 100 includes an evaporator 1, an absorber 2 provided in parallel with the evaporator 1, and an evaporator absorber body 3 that houses the evaporator 1 and the absorber 2. A high temperature regenerator 5 having a gas burner 4, a low temperature regenerator 6, a condenser 7 arranged in parallel with the low temperature regenerator 6, and a low temperature regenerator condensing the low temperature regenerator 6 and the condenser 7. The body 8, the low-temperature heat exchanger 12, the high-temperature heat exchanger 13, the refrigerant drain heat recovery unit 16, a rare absorption liquid pump P 1, a concentrated absorption liquid pump P 2, and a refrigerant pump P 3 are provided. Each device is connected by piping through absorption liquid pipes 21 to 25, refrigerant pipes 31 to 35, and the like.
Reference numeral 14 denotes a cold / hot water pipe for circulatingly supplying brine heat exchanged with the refrigerant in the evaporator 1 to a heat load (not shown) (for example, an air conditioner). A heat transfer tube 14 </ b> A formed in the section is arranged in the evaporator 1. A temperature sensor 61 for measuring the temperature of the brine flowing through the cold / hot water pipe 14 is provided on the downstream side of the heat transfer pipe 14 </ b> A of the cold / hot water pipe 14. Reference numeral 15 denotes a cooling water pipe for sequentially flowing the cooling water to the absorber 2 and the condenser 7, and the heat transfer pipes 15 </ b> A and 15 </ b> B formed in a part of the cooling water pipe 15 are respectively connected to the absorber 2 and the condenser. 7 is arranged. Reference numeral 50 is a control device that controls the absorption refrigerator 100 as a whole. The temperature sensor 61 outputs a measurement result to the control device 50 under the control of the control device 50.

  The absorber 2 has a function of absorbing the refrigerant vapor evaporated in the evaporator 1 into the absorption liquid and maintaining the pressure in the evaporator absorber body 3 in a high vacuum state. Under the absorber 2, a rare absorbing liquid reservoir 2A is formed in which the diluted absorbing liquid diluted by absorbing the refrigerant vapor is accumulated. The rare absorbing liquid reservoir 2A is controlled by the inverter 51 so that the frequency is variable. One end of the rare absorbent pipe 21 provided with the rare absorbent pump P1 is connected. The rare absorbent pipe 21 is branched into a first rare absorbent pipe 21A and a second rare absorbent pipe 21B on the downstream side of the rare absorbent pump P1, and the first rare absorbent pipe 21A is connected to the refrigerant drain heat recovery unit 16. , The second dilute absorption liquid pipe 21 </ b> B joins again after passing through the low temperature heat exchanger 12. Then, the other end of the rare absorbent pipe 21 is branched into a third rare absorbent pipe 21C and a fourth rare absorbent pipe 21D, and the third rare absorbent pipe 21C passes through the high-temperature heat exchanger 13, Opening to the gas layer part 5B located above the heat exchanging part 5A formed in the high temperature regenerator 5, the fourth rare absorbent liquid pipe 21D is connected to the gas layer part 6A formed in the upper part in the low temperature regenerator 6. It is open.

  Under the high-temperature regenerator 5, a gas burner 4 is provided with an igniter 4A for igniting a fuel such as city gas, and a fuel control valve (heat input control valve) 4B for controlling the amount of fuel to change the amount of heat source. Is housed. When the gas burner 4 receives the combustion signal output from the control device 50, the gas burner 4 burns the gas, and the opening degree of the fuel control valve 4 </ b> B is controlled by the control device 50 according to the temperature measured by the temperature sensor 61. The high-temperature regenerator 5 is formed with a heat exchanging unit 5 </ b> A that heats and regenerates the absorbing liquid using the flame of the gas burner 4 as a heat source above the gas burner 4. An exhaust path 17 through which exhaust gas combusted by the gas burner 4 circulates is connected to the heat exchanging section 5A, and the heat exchanging section 5A is connected to the side of the heat exchanging section 5A after being heated and regenerated by the heat exchanging section 5A. A concentrated absorbent reservoir 5C is formed in which the concentrated absorbent that has flowed out of the portion 5A accumulates. The concentrated absorbent pool 5C is provided with a liquid level sensor 52 for detecting the level of the absorbent stored in the concentrated absorbent pool 5C (in the high temperature regenerator 5).

  One end of the concentrated absorbent liquid pipe 22 is connected to the lower end of the concentrated absorbent pool 5C, and the other end of the concentrated absorbent liquid pipe 22 is an intermediate absorbent that extends from the low temperature regenerator 6 via the high temperature heat exchanger 13. Merge with tube 24. The high temperature heat exchanger 13 heats the absorption liquid flowing through the third rare absorption liquid pipe 21C with the high temperature of the high temperature absorption liquid flowing out from the concentrated absorption liquid reservoir 5C, and the fuel consumption of the gas burner 4 in the high temperature regenerator 5 The amount is reduced. The upstream side of the high-temperature heat exchanger 13 of the concentrated absorbent liquid pipe 22 and the absorber 2 are connected by an absorbent liquid pipe 23 with an on-off valve V1 interposed therebetween.

The low-temperature regenerator 6 uses the refrigerant vapor separated by the high-temperature regenerator 5 as a heat source to heat and regenerate the absorption liquid stored in the absorption liquid reservoir 6B formed below the gas layer portion 6A. In 6B, a heat transfer tube 31A formed in a part of the refrigerant tube 31 extending from the upper end of the high temperature regenerator 5 to the bottom of the condenser 7 is disposed. By circulating the refrigerant vapor through the refrigerant pipe 31, the heat of the refrigerant vapor is transmitted to the absorption liquid stored in the absorption liquid reservoir 6B via the heat transfer pipe 31A, and the absorption liquid is concentrated.
One end of an intermediate absorption liquid pipe 24 is connected to the absorption liquid reservoir 6B of the low-temperature regenerator 6, and the other end of the intermediate absorption liquid pipe 24 joins with the concentrated absorption liquid pipe 22 and the concentrated absorption liquid pipe 25. Become. The concentrated absorbent pipe 25 is connected to a concentrated sprayer 2C provided on the upper part of the gas layer 2B of the absorber 2 via the concentrated absorbent pump P2 and the low temperature heat exchanger 12. The low-temperature heat exchanger 12 is a second rare absorption liquid tube with the heat of the concentrated absorption liquid flowing out from the concentrated absorption liquid reservoir 5C of the high-temperature regenerator 5 and the intermediate absorption liquid flowing out from the absorption liquid reservoir 6B of the low-temperature regenerator 6. The rare absorption liquid flowing through 21B is heated. Further, on the upstream side of the concentrated absorbent pump P2, bypass pipes 25A and 25B for bypassing the concentrated absorbent pump P2 and the low-temperature heat exchanger 12 are provided, and the operation of the concentrated absorbent pump P2 is stopped. If so, the concentrated absorbent that has flowed out of the concentrated absorbent pool 5C of the high-temperature regenerator 5 and the intermediate absorbent that has flowed out of the absorbent pool 6B of the low-temperature regenerator 6 are transferred to the low-temperature heat through the bypass pipes 25A and 25B. It is supplied into the absorber 2 without going through the exchanger 12.

  As described above, the refrigerant liquid reservoir 7A formed at the gas layer portion 5B of the high temperature regenerator 5 and the bottom of the condenser 7 includes the heat transfer pipe 31A and the refrigerant drain piped to the absorption liquid reservoir 6B of the low temperature regenerator 6. The refrigerant pipe 31 is connected via the heat recovery unit 16. The refrigerant pipe 31 is provided with a damper (flow path resistance means) 41 for imparting flow resistance downstream of the refrigerant drain heat recovery device 16, and the flow rate of the refrigerant flowing through the refrigerant pipe 31 by the damper 41 is reduced. And the heat exchange is sufficiently performed between the refrigerant vapor in the refrigerant pipe 31 and the absorbent in the low temperature regenerator 6, and the refrigerant vapor in the refrigerant pipe 31 and the rare absorbent in the first rare absorbent pipe 21A. The heat exchange between the two is sufficiently performed.

  The heat transfer pipe 31A upstream side of the refrigerant pipe 31 and the gas layer portion 2B of the absorber 2 are connected by a refrigerant pipe 32 having an on-off valve V2. Further, the refrigerant liquid reservoir 7A of the condenser 7 and the gas layer portion 1A of the evaporator 1 are connected by a refrigerant pipe 33 in which a U seal portion 33A is interposed. A refrigerant liquid reservoir 1B in which liquefied refrigerant accumulates is formed below the evaporator 1, and the refrigerant liquid reservoir 1B and the spreader 1C disposed above the gas layer portion 1A of the evaporator 1 are refrigerant pumps P3. The refrigerant pipe 34 is connected. The refrigerant pipe 34 downstream side of the refrigerant pump P3 and the absorbing liquid reservoir 2A of the absorber 2 are connected by a refrigerant pipe 35 having an on-off valve V3 interposed therebetween. The outlet side of the heat transfer pipe 14A of the cold / hot water pipe 14 and the outlet side of the heat transfer pipe 15B of the cooling water pipe 15 are connected by a communication pipe 36 with an on-off valve V4 interposed therebetween.

  The absorption chiller 100 is subjected to a cooling operation in which cold water is taken out from the cold / hot water pipe 14 under the control of the control device 50. During the cooling operation, the evaporator 1 outlet side temperature (temperature measured by the temperature sensor 61) of brine (for example, cold water) circulated and supplied to a heat load (not shown) via the cold / hot water pipe 14 is a predetermined set temperature, For example, the amount of heat input to the absorption refrigeration machine 100 is controlled by the control device 50 so as to be 7 ° C. Specifically, the control device 50 starts all the pumps P1 to P3, burns the gas in the gas burner 4, and the gas burner 4 so that the temperature of the brine measured by the temperature sensor 61 becomes a predetermined 7 ° C. Control the firepower. During the cooling operation, the on-off valves V1 to V4 are closed.

The rare absorbent transported from the absorber 2 to the high temperature regenerator 5 by the rare absorbent pump P1 through the rare absorbent pipe 21 is heated by the flame by the gas burner 4 and the high temperature combustion gas in the high temperature regenerator 5. Therefore, the refrigerant in the rare absorbent is evaporated and separated. The concentrated absorbent whose concentration has been increased by evaporating and separating the refrigerant in the high-temperature regenerator 5 passes through the concentrated absorbent pipe 22 and the concentrated absorbent pump P2 of the concentrated absorbent pipe 25 via the high-temperature heat exchanger 13; It flows into the thick absorption liquid pipe 25.
The rare absorbent transported from the absorber 2 to the low temperature regenerator 6 by the rare absorbent pump P1 through the rare absorbent pipe 21 is supplied from the high temperature regenerator 5 through the refrigerant pipe 31 to the heat transfer pipe 31A. Heated by the flowing high-temperature refrigerant vapor, the refrigerant in the rare absorbent is evaporated and separated. The intermediate absorption liquid whose concentration has been increased by evaporating and separating the refrigerant in the low temperature regenerator 6 flows through the intermediate absorption liquid pipe 24, and joins in the concentrated absorption liquid pipe 25 and the concentrated absorption liquid pipe 25. The merged concentrated absorbent is sent to the absorber 2 via the low-temperature heat exchanger 12 and dispersed from above the concentrated liquid spreader 2C.

On the other hand, the refrigerant separated and generated by the low temperature regenerator 6 enters the condenser 7, condenses, and accumulates in the refrigerant liquid reservoir 7A. When a large amount of refrigerant liquid accumulates in the refrigerant liquid reservoir 7A, the refrigerant liquid flows out of the refrigerant liquid reservoir 7A, enters the evaporator 1 via the refrigerant pipe 33, and passes through the refrigerant pipe 34 by the operation of the refrigerant pump P3. The liquid is pumped and sprayed from the sprayer 1C onto the heat transfer tube 14A of the cold / hot water tube 14.
The refrigerant liquid sprayed on the heat transfer tube 14A evaporates by removing vaporization heat from the brine passing through the inside of the heat transfer tube 14A, so that the brine passing through the inside of the heat transfer tube 14A is cooled, and the brine thus lowered in temperature is A cooling operation such as cooling is performed by supplying the heat load from the cold / hot water pipe 14.
Then, the refrigerant evaporated in the evaporator 1 enters the absorber 2, is absorbed by the concentrated absorbent supplied from the high temperature regenerator 5 and the low temperature regenerator 6 and sprayed from above, and is stored in the rare absorbent pool of the absorber 2. The circulation which accumulates in 2A and is conveyed to the high temperature regenerator 5 by the rare absorption liquid pump P1 is repeated. Note that the heat generated when the absorbing liquid absorbs the refrigerant is cooled by the heat transfer pipe 15 </ b> A of the cooling water pipe 15 disposed in the absorber 2.

  By the way, in the absorption refrigerator 100, performance (COP) improves as the temperature of the cooling water supplied to the absorption refrigerator 100 (cooling water inlet temperature) decreases. Usually, the cooling water inlet temperature is set to about 32 ° C., and when the cooling water inlet temperature falls below an arbitrary temperature (for example, 17 ° C.), the high temperature regenerator 5 and the condenser are accompanied by a pressure drop of the high temperature regenerator 5. The differential pressure from 7 is reduced. Since the refrigerant pipe 31 is provided with the damper 41, when the differential pressure between the high temperature regenerator 5 and the condenser 7 is reduced, the fluidity of the refrigerant is lowered. As a result, a refrigerant liquid is accumulated near the low-temperature regenerator 6 in the refrigerant pipe 31 or a state in which the refrigerant liquid moves back and forth through the low-temperature regenerator 6 in the refrigerant pipe 31 (hereinafter simply referred to as a staying state). There is a risk that hunting may occur in which the outlet temperature of the brine supplied to the heat load repeatedly fluctuates up and down.

  Therefore, in the present embodiment, the bypass pipe 42 that bypasses the damper 41 provided in the refrigerant pipe 31, the on-off valve 43 provided in the bypass pipe 42, and the absorber 2 inlet side of the cooling water pipe 15 are provided. The cooling water temperature sensor 62 for measuring the cooling water inlet temperature and the control device (valve control means) 50 for controlling the on-off valve 43 according to the measurement result of the cooling water temperature sensor 62 are provided. As described above, the stagnation of the refrigerant is caused by the differential pressure between the high temperature regenerator 5 and the condenser 7, and in this embodiment, the differential pressure between the high temperature regenerator 5 and the condenser 7 is changed to the cooling water. Corresponds to the inlet temperature.

The on-off valve 43 is an operation valve configured to be fully openable and fully closeable, and is operated under the control of the control device 50. The coolant temperature sensor 62 outputs the measurement result to the control device 50 under the control of the control device 50.
As shown in FIG. 2, when the temperature measured by the coolant temperature sensor 62 becomes equal to or lower than the first temperature T1, the control device 50 fully opens the on-off valve 43. Here, the first temperature T1 is the cooling water inlet temperature immediately before the differential pressure between the high-temperature regenerator 5 and the condenser 7 shown in FIG. 1 decreases and the operation of the absorption chiller 100 starts to become unstable. It is acquired in advance by experiments or the like, and is set to 15 ° C. in this embodiment. Thereby, even if the cooling water inlet temperature is equal to or lower than the first temperature T1 (15 ° C.) and the differential pressure between the high-temperature regenerator 5 and the condenser 7 decreases, the bypass pipe 42 that bypasses the damper 41 with the refrigerant liquid is provided. Since it circulates, the refrigerant can be prevented from staying, and as a result, the absorption refrigerator 100 can be operated stably. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved.

  On the other hand, as shown in FIG. 2, when the temperature measured by the cooling water temperature sensor 62 becomes equal to or higher than the second temperature T2, the control device 50 fully closes the on-off valve 43. Here, the second temperature T2 is the cooling water inlet temperature when the differential pressure between the high-temperature regenerator 5 and the condenser 7 shown in FIG. In this embodiment, the temperature is set to 20 ° C., which is 5 ° C. higher than the first temperature T1. Accordingly, when the cooling water inlet temperature becomes equal to or higher than the second temperature T2 (20 ° C.) and the differential pressure between the high-temperature regenerator 5 and the condenser 7 increases, the refrigerant liquid does not flow through the bypass pipe 42. The flow rate of the refrigerant flowing through the refrigerant pipe 31 decreases, and the absorption liquid in the low temperature regenerator 6 and the rare absorption liquid in the first rare absorption liquid pipe 21A are sufficiently heated by the heat of the refrigerant vapor from the high temperature regenerator 5. Can do.

  As described above, in the present embodiment, the absorption refrigerator 100 having the damper 41 is provided with the bypass pipe 42 that bypasses the damper 41, and the bypass pipe 42 is provided with the on-off valve 43. The refrigerator 100 can be adapted to low-temperature cooling water. Further, since a relatively expensive pressure detecting means for detecting the pressure in the high temperature regenerator 5 and the condenser 7 is not required, an increase in cost due to the control of the on-off valve 43 can be suppressed. Furthermore, since the cooling water temperature sensor 62 is provided on the absorber 2 inlet side of the cooling water pipe 15, for example, compared to the case where it is provided on the absorber 2 outlet side of the cooling water pipe 15 or the condenser 7 outlet side, Stable temperature can be measured without being affected by inverter control of the cooling water pump (not shown), heat exchange in the absorber 2 and the condenser 7, and as a result, the on-off valve 43 can be controlled more accurately. become.

  As described above, according to the present embodiment, the cooling water pipe 15 for sequentially circulating the cooling water to the absorber 2 and the condenser 7 is provided, and the temperature of the cooling water is measured on the inlet side of the cooling water pipe 15. The cooling water temperature sensor 62 is provided, and the controller 50 that controls the on-off valve 43 according to the measurement result of the cooling water temperature sensor 62 is provided. With this configuration, for example, when the cooling water inlet temperature is low, the on-off valve 43 is controlled so as to increase the amount of refrigerant flowing through the bypass pipe 42, whereby the refrigerant in the refrigerant pipe 31 can easily flow. Therefore, the absorption refrigerator 100 can be operated stably. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved.

  Further, according to the present embodiment, the control device 50 is configured to fully open the on-off valve 43 when the temperature measured by the coolant temperature sensor 62 is equal to or lower than the first temperature T1. With this configuration, when the cooling water inlet temperature becomes equal to or lower than the first temperature T1, the refrigerant in the refrigerant pipe 31 can be made to flow easily, so that the absorption chiller 100 can be stably operated. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved.

  Further, according to the present embodiment, the control device 50 fully closes the on-off valve 43 when the temperature measured by the coolant temperature sensor 62 reaches the second temperature T2 higher than the first temperature T1. The configuration. With this configuration, when the cooling water inlet temperature becomes equal to or higher than the second temperature T2, the refrigerant liquid does not flow through the bypass pipe 42. Therefore, the flow rate of the refrigerant flowing through the refrigerant pipe 31 is reduced by the damper 41, and the high temperature regenerator 5 It is possible to sufficiently heat the absorption liquid in the low temperature regenerator 6 and the rare absorption liquid in the first rare absorption liquid pipe 21 </ b> A by the heat of the refrigerant vapor.

[Second Embodiment]
In the first embodiment, the control device 50 controls the on-off valve 43 according to the measurement result of the cooling water temperature sensor 62. However, in the second embodiment, the on-off valve 43 is controlled by the cooling water temperature sensor. Control is performed according to the measurement result 62 and the opening of the fuel control valve 4B.
Retention of the refrigerant is caused by the amount of refrigerant vapor generated in the high temperature regenerator 5 in addition to the differential pressure between the high temperature regenerator 5 and the condenser 7. There is a substantially proportional relationship with the ratio of the amount of refrigerant vapor generated at the opening degree to the maximum amount of refrigerant vapor generated in the above. Therefore, in the present embodiment, the differential pressure between the high-temperature regenerator 5 and the condenser 7 is made to correspond to the cooling water inlet temperature, and the generated amount of refrigerant vapor is made to correspond to the opening of the fuel control valve 4B.

  When the opening degree of the fuel control valve 4B is equal to or larger than the predetermined opening degree, the control device 50, when the temperature measured by the cooling water temperature sensor 62 becomes equal to or lower than the first temperature T1 (15 ° C.) as shown in FIG. The on-off valve 43 of the bypass pipe 42 is fully opened. When the predetermined opening degree is such that the amount of refrigerant vapor generated in the high temperature regenerator 5 is relatively large and the differential pressure between the high temperature regenerator 5 and the condenser 7 is small, the operation of the absorption chiller 100 becomes unstable. The opening degree immediately before starting to be obtained and obtained in advance through experiments or the like. In this embodiment, the amount of refrigerant vapor generated is set to 50%, which is 50% of the maximum. Thereby, in the state where the opening degree of the fuel control valve 4B is a predetermined opening degree (50%) or more and the generation amount of the refrigerant vapor in the high temperature regenerator 5 is relatively large, the cooling water inlet temperature is the first temperature T1 ( Even if the differential pressure between the high-temperature regenerator 5 and the condenser 7 becomes small, the refrigerant liquid flows through the bypass pipe 42 that bypasses the damper 41, so that the refrigerant can be prevented from staying. The absorption refrigerator 100 can be stably operated. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved.

  On the other hand, when the opening degree of the fuel control valve 4B is equal to or greater than a predetermined opening degree (50%), the control device 50 determines that the temperature measured by the cooling water temperature sensor 62 is the second temperature T2 (20 When the temperature is higher than or equal to (° C.), the on-off valve 43 is fully closed. Thereby, in the state where the opening degree of the fuel control valve 4B is equal to or larger than the predetermined opening degree (50%) and the amount of refrigerant vapor generated in the high temperature regenerator 5 is relatively large, the cooling water inlet temperature is set to the second temperature T2 ( When the pressure difference between the high-temperature regenerator 5 and the condenser 7 increases, the refrigerant liquid does not flow through the bypass pipe 42, so that the flow rate of the refrigerant flowing through the refrigerant pipe 31 by the damper 41 decreases, and the high temperature The absorption liquid in the low temperature regenerator 6 and the rare absorption liquid in the first rare absorption liquid pipe 21A can be sufficiently heated by the warm heat of the refrigerant vapor from the regenerator 5.

Further, even when the temperature measured by the cooling water temperature sensor 62 is equal to or lower than the first temperature T1 (15 ° C.), the control device 50 is configured such that when the opening degree of the fuel control valve 4B becomes less than a predetermined opening degree (50%), The on-off valve 43 is fully closed. That is, in the present embodiment, the condition that the temperature measured by the cooling water temperature sensor 62 is equal to or lower than the first temperature T1 (15 ° C.) and the opening degree of the fuel control valve 4B is equal to or higher than a predetermined opening degree (50%). Only when both of certain conditions are satisfied, the on-off valve 43 is opened. Thereby, even if the cooling water inlet temperature is equal to or lower than the first temperature T1 (15 ° C.) and the differential pressure between the high-temperature regenerator 5 and the condenser 7 is small, the opening degree of the fuel control valve 4B is the predetermined opening degree (50 %) And the amount of refrigerant vapor generated in the high-temperature regenerator 5 decreases, the refrigerant liquid does not flow through the bypass pipe 42, so the flow rate of the refrigerant flowing through the refrigerant pipe 31 by the damper 41 decreases, and the high-temperature regenerator The absorbing liquid in the low temperature regenerator 6 can be sufficiently heated by the heat of the refrigerant vapor from 5.
As described above, in the present embodiment, in addition to the differential pressure between the high temperature regenerator 5 and the condenser 7, the on-off valve 43 is controlled according to the amount of refrigerant vapor generated in the high temperature regenerator 5, Even if the differential pressure between the high-temperature regenerator 5 and the condenser 7 is small, when the amount of refrigerant vapor generated in the high-temperature regenerator 5 is small and the refrigerant does not easily stay, the on-off valve 43 is opened. Therefore, it is possible to suppress a decrease in the performance of the absorption refrigerator 100.

  As described above, according to the present embodiment, the fuel control valve 4B that controls the heat input amount of the high-temperature regenerator 5 is provided, and the control device 50 includes the measurement result of the coolant temperature sensor 62 and the fuel control valve 4B. The on-off valve 43 is controlled according to the opening degree. With this configuration, for example, when the cooling water inlet temperature is low and the opening degree of the fuel control valve 4B is large, the on-off valve 43 is controlled so as to increase the amount of refrigerant flowing through the bypass pipe 42. Since the refrigerant in the refrigerant pipe 31 can be made to flow easily, the absorption refrigeration machine 100 can be operated stably. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved. Further, when the amount of refrigerant vapor generated in the high-temperature regenerator 5 is small and it is difficult for the refrigerant to stay, it is possible to prevent the opening / closing valve 43 from being opened, so that the COP of the absorption refrigerator 100 can be improved. Can do.

[Third Embodiment]
FIG. 3 is a schematic configuration diagram illustrating an absorption refrigerator according to the third embodiment. The absorption refrigerator 200 of the present embodiment includes a pressure sensor 53 that detects the pressure in the high-temperature regenerator 5 and a refrigerant temperature sensor 63 that measures the temperature of the refrigerant on the outlet side of the refrigerant drain heat recovery unit 16 in the refrigerant pipe 31. The configuration is different from the absorption refrigerator 100 described above in that Since the other structure is the same as that of the absorption refrigerator 100, the same reference numerals are given and the description thereof is omitted.
In the first embodiment, the control device 50 controls the on-off valve 43 according to the measurement result of the cooling water temperature sensor 62, but in this embodiment, the measurement result of the cooling water temperature sensor 62, The on-off valve 43 is controlled according to the detection result of the pressure sensor 53 and the measurement result of the refrigerant temperature sensor 63.

  As described above, the stagnation of the refrigerant is caused by the differential pressure between the high temperature regenerator 5 and the condenser 7, and in this embodiment, the differential pressure between the high temperature regenerator 5 and the condenser 7 is changed to the cooling water. It corresponds to the inlet temperature and the pressure of the high temperature regenerator 5. Further, when the refrigerant stays, that is, when the flow rate of the refrigerant flowing through the refrigerant pipe 31 becomes slow, the amount of heat exchange in the low-temperature regenerator 6 and the refrigerant drain heat recovery unit 16 increases, and the refrigerant drain heat recovery is performed. Since the refrigerant temperature at the outlet side of the container 16 (refrigerant outlet temperature) is lowered, the refrigerant stagnation can also be detected by this refrigerant outlet temperature. Therefore, in the present embodiment, the flow rate of the refrigerant is made to correspond to the temperature of the refrigerant at the outlet side of the refrigerant drain heat recovery unit 16 of the refrigerant pipe 31.

The pressure sensor 53 detects the pressure in the high-temperature regenerator 5 under the control of the control device 50 and outputs the detection result to the control device 50. The refrigerant temperature sensor 63 outputs a measurement result to the control device 50 under the control of the control device 50.
When the pressure detected by the pressure sensor 53 is less than the predetermined pressure and the temperature measured by the refrigerant temperature sensor 63 is equal to or lower than the predetermined temperature, the control device 50 measures the cooling water temperature sensor 62 as shown in FIG. When the temperature falls below the first temperature T1 (15 ° C.), the on-off valve 43 of the bypass pipe 42 is fully opened. The predetermined pressure is such that the pressure in the high temperature regenerator 5 is low, the differential pressure between the high temperature regenerator 5 and the condenser 7 becomes small, and the high temperature regenerator 5 immediately before the operation of the absorption refrigeration machine 100 starts to become unstable. This pressure is acquired in advance through experiments or the like, and is set to 20 kPa based on the absolute pressure in this embodiment. Normally, the pressure in the high-temperature regenerator 5 is about 80 kPa on an absolute pressure basis. In addition, the predetermined temperature indicates that the flow rate of the refrigerant flowing through the refrigerant pipe 31 is slow, and that the temperature of the refrigerant is lowered by performing heat exchange more than usual in the low-temperature regenerator 6 and the refrigerant drain heat recovery unit 16. The refrigerant outlet temperature is obtained in advance through experiments or the like, and is set to 30 ° C. in the present embodiment. Normally, the refrigerant outlet temperature is about 40 ° C.

  Thus, in the state where the pressure in the high-temperature regenerator 5 is less than a predetermined pressure (20 kPa) and the temperature on the refrigerant drain heat recovery unit 16 outlet side of the refrigerant pipe 31 is equal to or lower than the predetermined temperature (30 ° C.), the cooling water inlet temperature Since the refrigerant liquid flows through the bypass pipe 42 that bypasses the damper 41 even when the temperature becomes equal to or lower than the first temperature T1 (15 ° C.) and the differential pressure between the high temperature regenerator 5 and the condenser 7 decreases, the refrigerant pipe 31 , The refrigerant liquid can be prevented from accumulating in the low temperature regenerator 6, and as a result, the absorption refrigerator 100 can be operated stably. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved.

  On the other hand, the control device 50 opens the fuel control valve 4B when the pressure detected by the pressure sensor 53 is less than the predetermined pressure (20 kPa) and the temperature measured by the refrigerant temperature sensor 63 is equal to or lower than the predetermined temperature (30 ° C.). When the degree is equal to or greater than the predetermined opening (50%), as shown in FIG. 2, when the temperature measured by the cooling water temperature sensor 62 becomes equal to or higher than the second temperature T2 (20 ° C.), the on-off valve 43 is fully closed. To do. Thus, when the pressure in the high-temperature regenerator 5 is less than the predetermined pressure (20 kPa) and the refrigerant outlet temperature is equal to or lower than the predetermined temperature (30 ° C.), the cooling water inlet temperature is equal to or higher than the second temperature T2 (20 ° C.). When the differential pressure between the high-temperature regenerator 5 and the condenser 7 increases, the refrigerant liquid does not flow through the bypass pipe 42, so that the flow rate of the refrigerant flowing through the refrigerant pipe 31 is reduced by the damper 41, The absorption liquid in the low temperature regenerator 6 and the rare absorption liquid in the first rare absorption liquid pipe 21A can be sufficiently heated by the heat of the refrigerant vapor.

  Further, the control device 50 determines that the pressure detected by the pressure sensor 53 is equal to or higher than a predetermined pressure (20 kPa) even if the temperature measured by the cooling water temperature sensor 62 is equal to or lower than the first temperature T1 (15 ° C.), or When the temperature measured by the refrigerant temperature sensor 63 becomes higher than a predetermined temperature (30 ° C.), the on-off valve 43 is fully closed. That is, in the present embodiment, the condition that the temperature measured by the cooling water temperature sensor 62 is equal to or lower than the first temperature T1 (15 ° C.), the condition that the pressure detected by the pressure sensor 53 is less than a predetermined pressure (20 kPa), and Only when the temperature measured by the refrigerant temperature sensor 63 is less than the predetermined temperature (30 ° C.), the on-off valve 43 is opened. Thereby, even if the cooling water inlet temperature is equal to or lower than the first temperature T1 (15 ° C.) and the differential pressure between the high temperature regenerator 5 and the condenser 7 is small, the pressure in the high temperature regenerator 5 is a predetermined pressure (20 kPa). If the refrigerant outlet temperature becomes higher than the predetermined temperature (30 ° C.) as described above, the refrigerant liquid does not flow through the bypass pipe 42, so that the flow rate of the refrigerant flowing through the refrigerant pipe 31 is reduced by the damper 41, and the high temperature regenerator 5 It is possible to sufficiently heat the absorption liquid in the low temperature regenerator 6 and the rare absorption liquid in the first rare absorption liquid pipe 21 </ b> A by the heat of the refrigerant vapor.

  As described above, in the present embodiment, the differential pressure between the high temperature regenerator 5 and the condenser 7 is made to correspond to both the cold / hot water inlet temperature and the pressure in the high temperature regenerator 5. The differential pressure with the vessel 7 can be detected reliably. In addition, since the on-off valve 43 is controlled according to the differential pressure between the high temperature regenerator 5 and the condenser 7 and the refrigerant outlet temperature, the refrigerant pipe can be used even if the differential pressure between the high temperature regenerator 5 and the condenser 7 is small. When the flow rate of the refrigerant flowing through the refrigerant 31 is fast and the refrigerant is unlikely to stay, the opening / closing valve 43 can be prevented from being opened, so that a decrease in the performance of the absorption refrigerator 100 can be suppressed. Furthermore, since a relatively expensive pressure detecting means for detecting the pressure in the condenser 7 is not required, an increase in cost due to control of the on-off valve 43 can be suppressed.

  As described above, according to the present embodiment, the refrigerant pipe 31 on the downstream side of the low-temperature regenerator 6 includes the refrigerant flowing through the refrigerant pipe 31 and the first rare absorption liquid pipe 21 </ b> A extending from the absorber 2. A refrigerant drain heat recovery device 16 that exchanges heat with the circulating rare absorbent is provided, a pressure sensor 53 that detects the pressure in the high temperature regenerator 5 is provided in the high temperature regenerator 5, and a refrigerant drain of the refrigerant pipe 31 is provided. A refrigerant temperature sensor 63 that measures the temperature of the refrigerant is provided on the outlet side of the heat recovery unit 16, and the control device 50 measures the measurement result of the cooling water temperature sensor 62, the detection result of the pressure sensor 53, and the measurement result of the refrigerant temperature sensor 63. The on-off valve 43 is controlled according to the above. With this configuration, for example, when the temperature of the cooling water is low, the pressure in the high-temperature regenerator 5 is low, and the temperature of the refrigerant at the outlet side of the refrigerant drain heat recovery device 16 is high, the bypass pipe 42 is provided. By controlling the on-off valve 43 so as to increase the amount of refrigerant flowing, the refrigerant in the refrigerant pipe 31 can be made to flow easily, so that the absorption refrigeration machine 100 can be operated stably. Therefore, since low temperature cooling water can be used, the COP of the absorption chiller 100 can be improved. Moreover, since the flow rate of the refrigerant | coolant which distribute | circulates the refrigerant | coolant pipe | tube 31 is high and it is hard to produce a refrigerant | coolant retention, it can prevent that the on-off valve 43 is opened, Therefore The COP of the absorption refrigeration machine 100 can be improved.

However, the above embodiment is an aspect of the present invention, and it is needless to say that the embodiment can be appropriately changed without departing from the gist of the present invention.
For example, in the above-described embodiment, the configuration including the gas burner 4 that heats the fuel gas by burning it as the heating means that heats the absorbing liquid in the high-temperature regenerator 5 has been described. It is good also as a structure provided with the burner which burns A heavy oil, or the structure heated using warm heat, such as a vapor | steam and exhaust gas.
In the above embodiment, the flow path resistance means is described as the damper 41. However, the flow path resistance means is not limited to this, and may be, for example, a flow rate control valve or an orifice.

  Moreover, in the said embodiment, the absorption refrigerator 100 is formed in what is called a parallel flow cycle in which the rare absorption liquid pipe 21 extended from the absorber 2 branches into the high temperature regenerator 5 and the low temperature regenerator 6. However, the present invention is not limited to this, for example, a so-called series flow cycle in which the absorption liquid flowing out from the high temperature regenerator is supplied to the low temperature regenerator, or a so-called reverse flow in which the absorption liquid flowing out from the low temperature regenerator is supplied to the high temperature regenerator. The present invention may be applied to an absorption refrigerator formed in a cycle.

  In the above embodiment, the absorption chiller / heater is a double-effect type, but this is not limited to single-effect type, single-double-effect type and triple-effect type absorption chiller / heater and absorption heat pump devices. Of course, the invention is applicable.

1 Evaporator 2 Absorber 4B Fuel control valve (heat input control valve)
DESCRIPTION OF SYMBOLS 5 High temperature regenerator 6 Low temperature regenerator 7 Condenser 15 Cooling water pipe 16 Refrigerant drain heat recovery device 21A 1st rare absorption liquid pipe (rare absorption liquid pipe)
31 Refrigerant pipe 41 Damper (flow path resistance means)
42 Bypass pipe 43 On-off valve 50 Control device (valve control means)
53 Pressure Sensor 62 Cooling Water Temperature Sensor 63 Refrigerant Temperature Sensor 100 Absorption Refrigerator

Claims (5)

A high-temperature regenerator, a low-temperature regenerator, an evaporator, a condenser, and an absorber are provided. The high-temperature regenerator and the condenser are connected by a refrigerant pipe passing through the low-temperature regenerator, and flow resistance is given to the refrigerant pipe. In the absorption refrigerator having a flow path resistance means and a bypass pipe that bypasses the flow path resistance means, and provided with an on-off valve in the bypass pipe,
Providing a cooling water pipe for circulating cooling water sequentially to the absorber and the condenser;
A cooling water temperature sensor for measuring the cooling water inlet temperature is provided on the absorber inlet side of the cooling water pipe,
Comprising valve control means for controlling the on-off valve according to the measurement result of the cooling water temperature sensor ,
The said valve control means opens the said on-off valve when the cooling water inlet temperature measured by the said cooling water temperature sensor is below 1st temperature, The absorption refrigerator characterized by the above-mentioned . The absorption chiller according to claim 1, wherein the valve control means fully opens the on-off valve when a cooling water inlet temperature measured by the cooling water temperature sensor is equal to or lower than a first temperature. The valve control means fully closes the on-off valve when a coolant inlet temperature measured by the coolant temperature sensor reaches a second temperature higher than the first temperature. 2. The absorption refrigerator according to 2. A heat input amount control valve for controlling the heat input amount of the high temperature regenerator,
The absorption chiller according to claim 1, wherein the valve control means controls the on-off valve in accordance with a measurement result of the cooling water temperature sensor and an opening degree of the heat input control valve. The refrigerant pipe at the downstream side of the low-temperature regenerator has a refrigerant drain heat recovery for exchanging heat between the refrigerant flowing through the refrigerant pipe and the rare absorbent flowing through the rare absorbent pipe extending from the absorber. Vessel is provided,
A pressure sensor for detecting the pressure in the high temperature regenerator is provided in the high temperature regenerator,
A refrigerant temperature sensor for measuring the temperature of the refrigerant is provided on the refrigerant drain heat recovery device outlet side of the refrigerant pipe,
The valve control means controls the on-off valve according to a measurement result of the cooling water temperature sensor, a detection result of the pressure sensor, and a measurement result of the refrigerant temperature sensor. The absorption refrigerator described.

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