JP5098547B2 - Absorption refrigeration system - Google Patents

Description

  The present invention relates to an absorption refrigeration apparatus driven by exhaust heat of an engine that drives a compression refrigeration apparatus.

  The conventional air-cooled absorption refrigeration system is a direct air-cooling method in which the solution is cooled by air-cooling fins while absorbing the refrigerant vapor by the absorber, and the absorber absorbs the refrigerant vapor and cools the absorbed solution at the same time. Expansion of the gas-liquid interface is important for performance improvement. However, for that purpose, large-diameter heat transfer tubes for reducing the pressure loss of the refrigerant vapor absorbed by the solution flowing on the upper and lower absorber headers and the wall of the absorber heat transfer tube, and the large size of the refrigerant vapor communication tube with the evaporator are used. It is necessary to reduce the diameter of the device, and there is a great restriction on downsizing the device.

  On the other hand, the solution flowing into the absorber is supercooled by an air-cooled cooler, and the refrigerant heat is simply absorbed in the absorber, and the absorbed heat is removed by sensible heat of the supercooled solution (solution The separation cooling method is considered to be the most advantageous method for a small air-cooled absorption refrigeration apparatus because the absorber is made smaller than before.

  If this indirect air-cooled air-cooled absorption refrigeration system is driven by using exhaust heat from the engine, the size and cost of the apparatus can be reduced. It can be easily changed to a form to be converted to use, the effective use of exhaust heat is promoted, and it can be considered that it can greatly contribute to energy saving and CO2 reduction.

  By the way, as a conventional example of this indirect air cooling type air cooling absorption refrigeration apparatus, for example, there is one disclosed in Patent Document 1, but in this conventional example, an absorber is a type that sprays a solution. Although it is adopted, it is a conventional direct-fire method in which a solution is heated by a burner with a double-effect cycle, and there is no example using exhaust heat.

  Also, the compression refrigeration unit is driven by the engine, the absorption refrigeration unit is driven by the exhaust heat, and the refrigerant of the compression refrigeration unit is supercooled by the cold heat so as to improve the performance of the compression refrigeration unit As a conventional example of a refrigeration system in which an absorption refrigeration apparatus and a compression refrigeration apparatus are combined, there are many examples such as that shown in Patent Document 2, for example.

JP-A-7-98163 JP-A-9-53864

  By the way, in a system combining a compression refrigeration apparatus driven by an engine and an absorption refrigeration apparatus driven by the exhaust heat, in the above-described conventional example, the cooling heat of the absorption refrigeration apparatus that simply uses the exhaust heat. Thus, the refrigerant of the compression refrigeration apparatus is supercooled.

  However, when the outside air temperature decreases or when the compression refrigeration apparatus becomes a partial load, the refrigerant temperature (that is, the condensation temperature) at the condenser outlet of the compression refrigeration apparatus decreases. When the drop in temperature and the partial load of the compression refrigeration unit overlap, the drop in refrigerant temperature at the condenser outlet of this compression refrigeration unit increases, so the evaporation temperature of the absorption refrigeration unit or the evaporator The cooled fluid temperature at the outlet (the refrigerant temperature of the compression refrigeration system) also decreases, and the evaporation temperature or the cooled fluid temperature is set based on a preset value (that is, based on the outside air temperature and the load of the compression refrigeration system). When the temperature is lower than the temperature value), the refrigerating capacity of the absorption refrigeration apparatus becomes excessive, and the refrigerant on the absorption refrigeration apparatus side is wasted.

  On the other hand, when the outside air temperature rises or when the load of the compression refrigeration apparatus increases, the refrigerant temperature at the condenser outlet of the compression refrigeration apparatus rises, so the evaporation temperature of the absorption refrigeration apparatus or the evaporator The temperature of the fluid to be cooled at the outlet of the refrigerant also rises, and if the evaporation temperature or the temperature of the fluid to be cooled rises above a preset value, the refrigerating capacity of the absorption refrigeration apparatus becomes insufficient. It is necessary to quickly increase the refrigeration capacity.

  Therefore, in order to improve the efficiency of the compression refrigeration system and reduce the running cost without installing a large capacity exhaust heat driven absorption refrigeration system, respond to changes in the operating conditions on the compression refrigeration system side. Therefore, it is necessary to control the refrigeration capacity of the absorption refrigeration apparatus.

  However, in the past, the absorption refrigeration was performed simply by supercooling the refrigerant of the compression refrigeration system with the cold heat of the absorption refrigeration system using the exhaust heat of the engine, in response to changes in operating conditions on the compression refrigeration system side. There is no idea of controlling the refrigeration capacity of the apparatus, and therefore there is room for improvement in terms of reducing initial costs and running costs.

  Therefore, the present invention controls the refrigeration capacity of the absorption refrigeration apparatus in accordance with the change in operating conditions on the compression refrigeration apparatus side in the absorption refrigeration apparatus driven by the exhaust heat of the engine that drives the compression refrigeration apparatus. Thus, an object of the present invention is to provide an absorption refrigeration apparatus that can improve the efficiency of the compression refrigeration apparatus and reduce the initial cost and running cost of the entire refrigeration system.

  In the present invention, the following configuration is adopted as a specific means for solving such a problem.

In 1st invention of this application, the generator 1 which act | operates in response to the exhaust heat of the engine 26 which drives the compression-type refrigeration apparatus X , the condenser 2 , the evaporator 3 which evaporates a refrigerant | coolant transiently, and a flow down In an exhaust heat-driven absorption refrigeration apparatus including a liquid film type absorber 4 and an air-cooled supercooler 6 for supercooling an absorbing solution entering the absorber 4 , the condenser 2 is changed to the evaporator 3 . While the refrigerant tank 14 and the refrigerant electromagnetic valve 10 are sequentially provided in the middle of the pipe 64, the temperature of the supercooling solution flowing into the absorber 4 and / or the flow rate of the supercooling solution is changed, so that the absorber 4 The refrigerant absorption capacity is increased or decreased to control the refrigeration capacity of the absorption refrigeration apparatus, and the temperature of the fluid to be cooled at the outlet of the evaporator 3 is calculated based on the outside air temperature and the condensation temperature of the compression refrigeration apparatus X. that when it becomes the target temperature or less, the absorber 4 At the same time varying the flow rate of the temperature of the supercooled solution to flow in and / or subcooled solution performs control to decrease the refrigerant absorption capacity of the absorber 4, it flows into the evaporator 3 to the refrigerant solenoid valve 10 as a closed The amount of refrigerant to be reduced is reduced to reduce the refrigeration capacity of the absorption refrigeration apparatus, and the refrigerant from the condenser 2 is stored in the refrigerant tank 14 while the temperature of the fluid to be cooled at the outlet of the evaporator 3 is the target. when a temperature or more, and at the same time the temperature and / or the supercooled solution by changing the flow amount increase refrigerant absorption capacity of the absorber 4 flowing into the absorber 4, the refrigerant solenoid valve 10 performs control for increasing the cooling capacity of the absorption refrigerating apparatus refrigerant retained in the refrigerant tank 14 by increasing the coolant flow rate to flow into the evaporator 3 is opened, the absorption refrigerating It is assumed that the operation / stop of the apparatus is controlled by the solution temperature of the generator 1, and even when the engine 26 is stopped, the solution temperature is equal to or higher than a predetermined temperature and the refrigerant storage capacity of the refrigerant tank 14 has a margin. In this case, the refrigerant solenoid valve 10 is closed, the absorption refrigeration apparatus is operated until the refrigerant tank 14 is full, or the solution pump 9 that causes the absorption diluted solution from the absorber 4 to flow into the generator 1. Only when the solution temperature of the generator 1 is equal to or lower than the predetermined temperature, the operation of the absorption refrigeration apparatus is stopped even if the refrigerant storage capacity of the refrigerant tank 14 is sufficient, or the solution pump 9 is stopped .

According to such a configuration, the temperature of the supercooled solution flowing into the absorber 4 and / or the flow rate of the supercooled solution is changed to increase or decrease the refrigerant absorption capacity of the absorber 4 to control the refrigeration capacity of the absorption refrigeration apparatus. By doing so, since it is not influenced by the load of the compression refrigeration apparatus X driven by the engine 26 , input control of exhaust heat is not particularly required when controlling the refrigeration capacity, and the control is simplified. The cost can be reduced.

Moreover, when the temperature of the fluid to be cooled at the outlet of the evaporator 3 becomes equal to or lower than the target temperature calculated based on the outside air temperature and the condensation temperature of the compression refrigeration apparatus X , the fluid flows into the absorber 4 . Control is performed to reduce the refrigerant absorption capacity of the absorber 4 by changing the temperature of the supercooled solution and / or the flow rate of the supercooled solution, and at the same time, the refrigerant flowing into the evaporator 3 with the refrigerant solenoid valve 10 closed. By reducing the amount and reducing the refrigeration capacity of the absorption refrigeration apparatus, the refrigeration capacity of the absorption refrigeration apparatus can be made to correspond to the degree of supercooling on the compression refrigeration apparatus X side, and in that case, By accumulating the refrigerant from the condenser 2 in the refrigerant tank 14 , the amount of ineffective refrigerant on the absorption refrigeration apparatus side can be reduced.

On the other hand, when the temperature of the fluid to be cooled at the outlet of the evaporator 3 is equal to or higher than the target temperature , the temperature of the supercooled solution flowing into the absorber 4 and / or the flow rate of the supercooled solution is changed. The refrigerant absorption capacity of the absorber 4 is increased, and at the same time, the refrigerant electromagnetic valve 10 is opened and the refrigerant stored in the refrigerant tank 14 is caused to flow into the evaporator 3 to increase the refrigerant flow rate. By increasing the refrigerating capacity of the compressor, the supercooling temperature of the refrigerant of the compression refrigeration apparatus X increases, and the performance of the compression refrigeration apparatus X is improved as compared with the normal state in which the above control is not performed. .

Furthermore, even if the engine 26 is in a stopped state, when the refrigerant can be generated and the refrigerant can be stored in the refrigerant tank 14, the refrigerant is stored in the refrigerant tank 14, The amount of ineffective refrigerant can be reduced to effectively use the refrigerant.

As the above synergistic effect, the improvement of the efficiency of the compression refrigeration system and the reduction of the initial cost and the running cost of the entire refrigeration system can be achieved at the same time, and the effective use of the refrigerant can be achieved by reducing the amount of the invalid refrigerant. Can

In a second aspect of the present invention, in the above absorption type refrigerating apparatus according to the first invention, and the target temperature at which a closed the refrigerant solenoid valve 10 from the open, the refrigerant solenoid valve 10 if the from the closed to the open The target temperature is set to the same temperature or different temperatures.

According to such a configuration, for example, when the target temperature in the case where the refrigerant solenoid valve 10 is changed from open to closed and the target temperature in the case where the refrigerant solenoid valve 10 is changed from closed to open is set to the same temperature, compared with a case where this is set to a different temperature. Although the control can be simplified and the cost of the apparatus can be reduced, the refrigerant solenoid valve 10 is frequently opened and closed. Also, when the target temperature when the refrigerant electromagnetic valve 10 is changed from open to closed and when the target temperature is changed from closed to open, for example, when the refrigerant electromagnetic valve 10 is changed from open to closed (that is, the refrigerant tank) 14 is set lower than the target temperature when the refrigerant solenoid valve 10 is opened from the closed state (that is, when the refrigerant stored in the refrigerant tank 14 starts to flow out). Then, the increase control of the refrigerating capacity is started earlier, and the quick increase of the refrigerating capacity is realized.

In a third aspect of the present invention, in the first or absorption type refrigerating apparatus according to the second invention, a weir 14a provided in the refrigerant tank 14, the refrigerant in the evaporator 3-flowed Yue the weir 14a In addition, the refrigerant flow rate to the evaporator 3 is increased or decreased by opening and closing the refrigerant electromagnetic valve 10 .

According to this configuration, when the refrigerant solenoid valve 10 is opened from the closed state, that is, when the refrigerant stored after the refrigerant is stored in the refrigerant tank 14 is flowed to the evaporator 3 side, the refrigerant is always used. Since the refrigerant is stored in the tank 14 , a sufficient amount of the refrigerant is caused to flow to the evaporator 3 side simultaneously with the opening operation of the refrigerant electromagnetic valve 10 , and the increase control of the refrigerating capacity is performed more quickly and reliably. It is.

In the fourth aspect of the present invention, the first, the second or the absorption type refrigerating apparatus according to the third invention, the surplus refrigerant after the refrigerant tank 14 becomes full, the bottom of the evaporator 3 Or directly flowing into the dilute solution reservoir 16 of the absorber 4 .

According to such a configuration, surplus refrigerant is allowed to flow into the lower part of the evaporator 3 or directly into the dilute solution reservoir 16 of the absorber 4 and be mixed with the absorbed dilute solution in the dilute solution reservoir 16 . Since the concentration change of the absorbing solution can be suppressed, the solution crystal can be avoided by freezing the refrigerant in the evaporator 3 and increasing the concentration in the generator 1 without excessively concentrating the solution.

In the fifth aspect of the present invention, the first, the second, third or absorption refrigerating apparatus according to the fourth invention, the increase and decrease control of the flow rate of refrigerant flowing from the refrigerant tank 14 to the evaporator 3, It is characterized by Nau line by the opening and closing of the refrigerant solenoid valve 10.

According to such a configuration, the amount of refrigerant flowing into the evaporator 3 can be finely increased / decreased, so that the control of the refrigeration capacity of the absorption refrigeration apparatus corresponds to the load change on the compression refrigeration apparatus X side. And can be precisely controlled.

In the sixth invention of the present application, the first, second, third, fourth or the absorption type refrigerating apparatus according to the fifth invention, start-stop of the fan 7 provided in the air-cooled subcooler 6 or The refrigeration capacity is controlled by changing the temperature of the supercooled solution flowing into the absorber 4 by increasing or decreasing the air volume.

According to such a configuration, the control of the refrigerating capacity by changing the temperature of the supercooled solution can be performed very easily and quickly by making use of the characteristics of the indirect air cooling system and by the start / stop of the fan 7 or the increase / decrease of the air volume. Therefore, the capacity control range of the absorption refrigeration apparatus can be reduced to the minimum capacity, and as a result, the capacity of the compression refrigeration apparatus X can be utilized to the limit.

In the seventh invention of the present application, the first, second, third, flow rate 4 also provided in the absorption type refrigerating apparatus according to a fifth aspect of the invention, the inlet side or the outlet side of the air-cooled subcooler 6 The refrigerating capacity is controlled by changing the flow rate of the supercooled solution flowing into the absorber 4 by the adjusting valve 11 or 12 .

According to such a configuration, the control of the refrigerating capacity can be performed very easily and quickly by adjusting the flow rate of the supercooled solution by the flow rate adjusting valve 11 or 12, so that the capacity control range of the absorption refrigeration apparatus is reduced to the minimum capacity. As a result, the capacity of the compression refrigeration apparatus X can be utilized to the limit.

In the eighth invention of the present application, the first, second, third, fourth or the absorption type refrigerating apparatus according to a fifth invention, the dilute solution from the absorber 4 which has absorbed the refrigerant vapor, the Refrigerating capacity is controlled by increasing or decreasing the flow rate of the solution pump 9 that generates refrigerant vapor in the generator 1 and sucks and discharges the mixed solution with the concentrated solution whose temperature has decreased due to heat exchange in the solution heat exchanger 5. It is characterized by that.

According to such a configuration, since the refrigeration capacity can be controlled easily and quickly by increasing / decreasing the flow rate of the solution pump 9 , the capacity control range of the absorption refrigeration apparatus can be reduced to the minimum capacity. The capacity of the compression refrigeration apparatus X can be utilized to the limit.

As a result of the above, according to the absorption refrigeration apparatus of the present invention, the efficiency of the compression refrigeration apparatus X is controlled by controlling the refrigeration capacity of the absorption refrigeration apparatus in response to changes in operating conditions on the compression refrigeration apparatus X side. Improvement in the initial cost and running cost of the entire refrigeration system can be achieved, and the amount of ineffective refrigerant can be reduced to effectively use the refrigerant .

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

I: First Embodiment FIG. 1 shows a refrigeration system according to a first embodiment of the present invention. This refrigeration system is configured by combining an exhaust heat driven absorption refrigeration apparatus Z and a compression refrigeration apparatus X.

The absorption refrigeration apparatus Z is an exhaust heat driven air-cooled absorption refrigeration apparatus that employs water (H 2 O) as a refrigerant, lithium bromide (LiBr) as an absorption liquid, and uses exhaust hot water as a heating source. In the heat exchanger 1a, the absorption diluted solution is heated with exhaust hot water to generate the refrigerant vapor and the absorption concentrated solution, and the refrigerant vapor flowing from the generator 1 through the pipe 51 is condensed to produce the refrigerant. The liquid to be cooled, and the fluid to be cooled (that is, the refrigerant exiting from the condenser 23 of the compression refrigeration apparatus X described below) flow into the condenser 2 and the refrigerant liquid flowing in from the condenser 2 through the pipe 52. The evaporator 3 which is sprayed on the plate surface of the plate heat exchanger 3a and temporarily evaporates it, and the falling liquid film which absorbs the refrigerant vapor generated in the evaporator 3 and generates an absorption dilute solution Absorber 4 and pipe to generator 1 above A solution heat exchanger 5 for exchanging heat in the plate heat exchanger 5a between the absorbing dilute solution flowing in through 53 and the absorbing concentrated solution flowing out from the generator 1 through the pipe 54, and absorption from the solution heat exchanger 5. A fan 7 is provided that allows a mixed solution of the concentrated solution and the diluted diluted solution in the diluted solution reservoir 16 provided at the lower part of the absorber 4 to flow into the absorber 4 by flowing it through the pipe 55. An air-cooled supercooler 6 and a solution pump 9 for allowing the absorbed dilute solution from the absorber 4 to flow into the generator 1 via the solution heat exchanger 5 are provided.

Here, the evaporator 3 and the absorber 4 are housed in an integral housing 15, and the unevaporated refrigerant flowing down to the lower part of the evaporator 3 flows through the bottom wall of the housing 15 as it is. It flows into the dilute solution reservoir 16 provided in the lower part of, is mixed into the absorbent dilute solution of rare-solution reservoir or Ri 16. As a result, the solution concentration is prevented from greatly changing due to an increase or decrease in the amount of refrigerant generated in the generator 1.

Further, the middle of the pipe line 52 connecting the condenser 2 and the evaporator 3 and the evaporator 3 are connected by a bypass pipe line 64. The bypass pipe 64 is provided with the refrigerant tank 14 and the refrigerant solenoid valve 10 sequentially from the upstream side. Accordingly, at the time of closing operation of the refrigerant solenoid valve 10, while the refrigerant is accumulated in the refrigerant tank 14, the refrigerant at the time of opening operation of the refrigerant solenoid valve 10 pooled in the refrigerant tank 14 to the evaporator 3 side Supplied.

  The compression refrigeration apparatus X is configured by connecting a compressor 21, an evaporator 22, a condenser 23, an expansion valve 24, and a four-way valve 25 that are driven by an engine 26 through a pipeline. Then, the liquid refrigerant condensed and flowing out in the condenser 23 flows into the plate heat exchanger 3a of the evaporator 3 on the absorption refrigeration apparatus Z side from the lower end side through the pipe 61, The refrigerant flows out from the upper end side to the evaporator 22 side through the pipe line 62. At that time, it is supercooled in the plate heat exchanger 3a of the evaporator 3 of the absorption refrigeration apparatus.

  In order to drive the absorption refrigeration apparatus Z using the exhaust water of the engine 26 of the compression refrigeration apparatus X as a heat source, the cooling water circulation system of the engine 26 and the heat exchanger 1a of the generator 1 are connected to each other by a pipe. 57 and 58 are connected.

  The refrigeration system configured as described above operates as follows.

  First, in the compression refrigeration apparatus X, the compressor 26 of the compression refrigeration apparatus X is driven by the engine 26, and the gas refrigerant discharged from the compressor 21 is condensed in the condenser 23 to be liquid refrigerant. In addition, the liquid refrigerant is further supercooled in the evaporator 3 on the absorption refrigeration apparatus Z side, and the supercooled refrigerant is evaporated in the evaporator 22 to cool the room. In this case, the refrigeration capacity can be improved by supercooling the liquid refrigerant from the condenser 23.

  On the other hand, in the absorption refrigeration apparatus Z, the generator 1 receives the hot water from the engine 26, and the generator 1 heats the absorption dilute solution from the absorber 4 to generate refrigerant vapor and the absorption concentrated solution. . The refrigerant vapor generated in the generator 1 is condensed in the air-cooled condenser 2 provided with a fan 8 to be a liquid refrigerant.

  Here, the liquid refrigerant from the condenser 2 flows into the upper part of the evaporator 3 through each of the pipe line 52 and the bypass pipe line 64 when the refrigerant solenoid valve 10 is open. Is done. Further, when the refrigerant solenoid valve 10 is in a closing operation, a part of the liquid refrigerant from the condenser 2 flows into the upper part of the evaporator 3 through the conduit 52, and the other part of the liquid refrigerant. The refrigerant is stored in the refrigerant tank 14. Accordingly, the amount of liquid refrigerant flowing into the evaporator 3 increases when the refrigerant solenoid valve 10 is opened and decreases when the refrigerant solenoid 10 is closed.

  The liquid refrigerant that has flowed into the upper portion of the evaporator 3 is evenly spread from the spreader (not shown) to the upper portion of the plate heat exchanger 3a and flows down along the surface of the heat exchanger 3a. Evaporate in the middle to generate refrigerant vapor. At this time, the refrigerant on the compression refrigeration apparatus X side flowing in the plate heat exchanger 3a is supercooled by the heat of evaporation.

On the other hand, in the absorber 4, the absorption dilute solution supercooled in the air-cooled supercooler 6 is evenly sprayed from the sprayer (not shown) to the plate 4a and flows down along the plate 4a. absorbs refrigerant vapor from the evaporator 3 is an absorption dilute solution, it is stored in the dilute solution reservoir or Ri 16.

In the dilute solution reservoir or Ri 16, a mixed solution consisting of unvaporized refrigerant flowing down to the lower absorption dilute solution having absorbed the refrigerant vapor in the absorber 4 without evaporated in the evaporator 3 is stored At the same time, the mixed solution is supplied to the generator 1 side by the solution pump 9. At this time, in the solution heat exchanger 5, heat recovery is performed by heat exchange between the absorption diluted solution from the absorber 4 side and the absorption concentrated solution generated in the generator 1.

  In the absorption refrigeration apparatus Z, the refrigeration capacity is increased or decreased by adjusting the absorption capacity in the absorber 4. That is, by increasing the absorption capacity of the absorber 4 and increasing the absorption of refrigerant vapor into the absorption diluted solution, the evaporation capacity in the evaporator 3 (that is, the supercooling capacity for the refrigerant on the compression refrigeration apparatus X side). As a result, the refrigerating capacity of the absorption refrigeration apparatus Z as a whole is enhanced.

  By the way, as described above, the refrigeration capacity of the compression refrigeration apparatus X varies depending on the degree of supercooling of the refrigerant discharged from the condenser 23, and the refrigeration capacity increases as the degree of supercooling increases. Therefore, in terms of improving the capacity of the compression refrigeration apparatus X, the refrigerant on the compression refrigeration apparatus X side needs to be supercooled as much as possible by the cold heat of the absorption refrigeration apparatus Z. What is necessary is just to combine the absorption refrigeration apparatus Z of the capability which can achieve the supercooling temperature corresponding to the refrigerating capacity of the refrigeration apparatus X.

  However, when the outside air temperature decreases or when the compression refrigeration apparatus becomes a partial load, the refrigerant temperature (that is, the condensation temperature) at the condenser outlet of the compression refrigeration apparatus decreases. When the drop in temperature and the partial load of the compression refrigeration unit overlap, the drop in refrigerant temperature at the condenser outlet of this compression refrigeration unit increases, so the evaporation temperature of the absorption refrigeration unit or the evaporator The cooled fluid temperature at the outlet (the refrigerant temperature of the compression refrigeration system) also decreases, and the evaporation temperature or the cooled fluid temperature is set based on a preset value (that is, based on the outside air temperature and the load of the compression refrigeration system). When the temperature is lower than the temperature value), the refrigerating capacity of the absorption refrigeration apparatus becomes excessive, and the refrigerant on the absorption refrigeration apparatus side is wasted.

  On the other hand, when the outside air temperature rises or when the load of the compression refrigeration apparatus increases, the refrigerant temperature at the condenser outlet of the compression refrigeration apparatus rises, so the evaporation temperature of the absorption refrigeration apparatus or the evaporator The temperature of the fluid to be cooled at the outlet of the refrigerant also rises, and if the evaporation temperature or the temperature of the fluid to be cooled rises above a preset value, the refrigerating capacity of the absorption refrigeration apparatus becomes insufficient. In addition, it is necessary to quickly increase the refrigerating capacity by increasing the supercooling temperature or the supercooling flow rate of the solution flowing into the absorber and at the same time increasing the refrigerant flow rate to the evaporator.

  Therefore, in order to improve the efficiency of the compression refrigeration system and reduce the running cost without installing a large capacity exhaust heat driven absorption refrigeration system, respond to changes in the operating conditions on the compression refrigeration system side. Therefore, it is necessary to control the refrigeration capacity of the absorption refrigeration apparatus.

  Therefore, in this embodiment, in consideration of these circumstances, by controlling the refrigeration capacity of the absorption refrigeration apparatus Z in accordance with the change in the operating condition on the compression refrigeration apparatus X side, a large amount of exhaust heat can be obtained. The efficiency of the compression refrigeration apparatus X is improved without installing a driving absorption refrigeration apparatus Z, and the running cost is reduced.

  In order to realize such control, in this embodiment, the refrigerant absorption capacity of the absorber 4 is increased or decreased by changing the temperature of the supercooled solution flowing into the absorber 4, so that the absorption refrigeration apparatus Z The refrigeration capacity is controlled, and under such a configuration, the temperature of the fluid to be cooled at the outlet of the evaporator 3 is equal to or lower than the target temperature calculated based on the outside air temperature and the condensation temperature of the compression refrigeration apparatus X. In this case, the temperature of the supercooled solution flowing into the absorber 4 is changed to reduce the refrigerant absorption capacity of the absorber 4, and at the same time, the refrigerant electromagnetic valve 10 is closed and the evaporator 3 is closed. The amount of refrigerant flowing in is reduced to reduce the refrigeration capacity of the absorption refrigeration apparatus Z, and the refrigerant from the condenser 2 is stored in the refrigerant tank 14. When the temperature becomes equal to or higher than the target temperature, the temperature of the supercooled solution flowing into the absorber 4 is changed to reduce the refrigerant absorption capacity of the absorber 4, and at the same time, the refrigerant solenoid valve 10 is opened, and the refrigerant stored in the refrigerant tank 14 is caused to flow into the evaporator 3 to increase the refrigerant flow rate, thereby increasing the refrigeration capacity of the absorption refrigeration apparatus Z.

  Specifically, a temperature sensor 18 is provided on the outlet side of the evaporator 3 to detect the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side on the outlet side, while the condensation of the compression refrigeration apparatus X is performed. The temperature sensor 19 is provided in the pipe line 61 on the outlet side of the vessel 23 to detect the condenser temperature (that is, the refrigerant condensation temperature), and the outside air temperature sensor 20 is provided to detect the outside air temperature.

  Then, based on the condenser temperature detected by the temperature sensor 19 and the outside air temperature detected by the outside air temperature sensor 20, the target temperature (target supercooling) on the outlet side of the evaporator 3 of the absorption refrigeration apparatus Z is determined. Temperature) is set, the target temperature is compared with the refrigerant temperature on the compression refrigeration apparatus X side detected by the temperature sensor 18 (that is, the actual supercooling temperature), and the refrigerant temperature becomes the target temperature. Thus, the degree of supercooling by the absorption refrigeration apparatus Z, that is, the refrigeration capacity required for the absorption refrigeration apparatus Z is controlled. Here, the actual supercooling temperature is detected as the refrigerant temperature on the compression refrigeration apparatus X side, but is not limited to this. For example, the refrigerant evaporating temperature in the evaporator 3 is detected. Can also be used.

  Specific control of the refrigeration capacity of the absorption refrigeration apparatus Z is as follows.

  That is, when the temperature of the refrigerant at the outlet of the evaporator 3 is equal to or lower than the target temperature calculated based on the outside air temperature and the condensation temperature of the compression refrigeration apparatus X, the air cooling supercooler 6 is provided. Control to reduce the refrigerant absorption capacity of the absorber 4 by changing the temperature of the supercooled solution circulating in the air-cooled supercooler 6 by starting and stopping the fan 7 or by increasing or decreasing the air volume of the fan 7. At the same time, the refrigerant solenoid valve 10 is closed to reduce the amount of refrigerant flowing into the evaporator 3, thereby reducing the refrigeration capacity of the absorption refrigeration apparatus Z. As a result, the refrigeration capacity of the absorption refrigeration apparatus Z can be made to correspond to the degree of supercooling required on the compression refrigeration apparatus X side. In this case, the amount of inactive refrigerant on the absorption refrigeration apparatus Z side can be reduced by storing the refrigerant (excess refrigerant) from the condenser 2 in the refrigerant tank 14.

  On the other hand, when the temperature becomes equal to or higher than the target temperature, the temperature of the supercooled solution flowing into the absorber 4 is changed to reduce the refrigerant absorption capacity of the absorber 4, and at the same time, the refrigerant electromagnetic valve 10 is opened, the refrigerant stored in the refrigerant tank 14 is caused to flow into the evaporator 3, and the refrigerant flow rate is increased to increase the refrigeration capacity of the absorption refrigeration apparatus Z, thereby controlling the compression refrigeration apparatus. The supercooling temperature of the refrigerant of X increases, and the performance of the compression refrigeration apparatus X is improved compared to the normal state where the above control is not performed.

  Furthermore, the refrigerant is stored in the refrigerant tank 14 not only when the engine 26 is in operation and the refrigerant electromagnetic valve 10 is in a closed operation, but also when the operation of the engine 26 is stopped. That is, even when the engine 26 is in a stopped state, if the solution temperature of the generator 1 is equal to or higher than a predetermined temperature and the refrigerant storage capacity of the refrigerant tank 14 has a margin, the refrigerant electromagnetic valve 10 is closed. The refrigerant is stored in the refrigerant tank 14 by operating the absorption refrigeration apparatus Z until the refrigerant tank 14 is full or operating only the solution pump 9. If the solution temperature of the generator 1 is equal to or lower than the predetermined temperature, even if the refrigerant storage capacity of the refrigerant tank 14 is sufficient, the operation of the absorption refrigeration apparatus Z is stopped, or the solution pump 6 is stopped, and the storage of the refrigerant in the refrigerant tank 14 is stopped.

  According to such a configuration, even when the engine 26 is stopped, the refrigerant is stored in the refrigerant tank 14 when the refrigerant can be generated and the refrigerant can be stored in the refrigerant tank 14. Therefore, the amount of ineffective refrigerant can be reduced to effectively use the refrigerant.

  As the above synergistic effect, the improvement of the efficiency of the compression refrigeration apparatus X and the reduction of the initial cost and the running cost of the entire refrigeration system are compatible.

  In this embodiment, the target temperature when the refrigerant solenoid valve 10 is changed from open to closed and the target temperature when the refrigerant electromagnetic valve 10 is changed from closed to open are set to the same temperature, but the present invention is limited to this. Instead, it can be at a different temperature. For example, when the refrigerant electromagnetic valve 10 is opened to closed (that is, the refrigerant starts to be stored in the refrigerant tank 14), the target temperature is set to the target temperature when the refrigerant electromagnetic valve 10 is opened from the closed (that is, the refrigerant tank 14). When the temperature is set lower than the target temperature of the refrigerant stored in the refrigerant, the increase control of the refrigerating capacity is started earlier, and the quick increase of the refrigerating capacity is realized.

Further, the piping 52 from the condenser 2 to the evaporator 3 can be omitted and simplified, and in this case, the refrigerant supplied to the evaporator 3 is only when the refrigerant electromagnetic valve 10 is open, Although the refrigerant can be used effectively, it is necessary to control the refrigerant solenoid valve 10 more complicatedly.

II: Second Embodiment FIG. 2 shows a refrigeration system according to a second embodiment of the present invention. This refrigeration system has the same basic configuration as that of the refrigeration system according to the first embodiment, and is configured by combining an exhaust heat-driven absorption refrigeration apparatus Z and a compression refrigeration apparatus X.

And the point that the refrigerating system concerning this embodiment differs from the refrigerating system concerning the 1st embodiment of the above,
The refrigerant tank 14 is provided with a weir 14a, and the liquid refrigerant that has overflowed the weir 14a out of the liquid refrigerant from the condenser 2 is caused to flow into the evaporator 3 side through the conduit 52. ,
As after the refrigerant tank 14 becomes full, to flow into the said dilute solution reservoir or Ri 16 the liquid refrigerant is provided directly via the bypass line 56 to the lower portion of the absorber 4 from the condenser 2 And
The capacity of the absorber 4 is adjusted by adjusting the opening degree of the flow rate adjusting valve 11 provided on the upstream side of the air-cooled supercooler 6 or the flow rate adjusting valve 12 provided on the downstream side and adjusting the flow rate of the solution pump 9. The point is that the temperature is adjusted by controlling the temperature of the supercooled solution circulating in the air-cooled supercooler 6.

  Here, the operational effects peculiar to the above differences are as follows.

  The weir 14 a is provided in the refrigerant tank 14, and the liquid refrigerant that has flown over the weir 14 a out of the liquid refrigerant from the condenser 2 is caused to flow into the evaporator 3 through the pipe 52. When the refrigerant solenoid valve 10 is opened, that is, when the refrigerant stored in the refrigerant tank 14 flows to the evaporator 3 side, the refrigerant tank 14 is always full of refrigerant. As a result, a sufficient amount of refrigerant is caused to flow toward the evaporator 3 simultaneously with the opening of the refrigerant solenoid valve 10, and the increase control of the refrigerating capacity is performed more quickly and reliably.

As after the refrigerant tank 14 becomes full, to flow into the said dilute solution reservoir or Ri 16 the liquid refrigerant is provided directly via the bypass line 56 to the lower portion of the absorber 4 from the condenser 2 As a result, the concentration change of the absorbing solution can be suppressed.

  By adjusting the capacity of the absorber 4 by adjusting the opening degree of the flow rate adjusting valve 11 or the flow rate adjusting valve 12 and adjusting the flow rate of the solution pump 9, it is very easy to control the refrigerating capacity of the absorption refrigeration apparatus Z. And since it can be performed quickly, the capacity control range of the absorption refrigeration apparatus Z can be reduced to the minimum capacity, and as a result, the capacity of the compression refrigeration apparatus X can be utilized to the limit.

  In addition, although the said refrigerant | coolant electromagnetic valve 10 is set as the structure which opens or closes the said bypass pipe line 64, in other embodiment, this can also be replaced with the refrigerant | coolant flow control valve which can adjust flow volume. In the case of such a configuration, the amount of refrigerant flowing into the evaporator can be controlled more or less finely as compared with the case of the refrigerant solenoid valve 10, so that the refrigerating capacity of the absorption refrigeration apparatus Z can be increased. The control can be more precisely controlled in accordance with the load change on the compression refrigeration apparatus X side.

  Since the structure and the effect other than the above are the same as those in the case of the first embodiment, here, after attaching the same reference numerals to the respective structural members in FIG. The corresponding explanation in the first embodiment is used, and the explanation here is omitted.

1 is a system diagram of an absorption refrigeration apparatus according to a first embodiment of the present invention. It is a system diagram of an absorption refrigeration apparatus according to a second embodiment of the present invention.

1 ·· Generator 2 ·· Condenser 3 ·· Evaporator 4 ··· Absorber 5 ·· Solution heat exchanger 6 ·· Air-cooled supercooler 7 ·· Fan 8 ·· Fan 9 ·· Solution pump 10 ··· refrigerant solenoid valve 11 ... flow control valve 12 ... flow control valve 14 ... refrigerant tank 14a .. weir 15 · skeleton 16 ... dilute solution reservoir or Ri 18 ... temperature sensor 19 ... temperature sensor 20 ... outside Air temperature sensor 21 ・ ・ Compressor 22 ・ ・ Evaporator 23 ・ ・ Condenser 24 ・ ・ Expansion valve 25 ・ ・ Four-way valve 26 ・ ・ Engine 30 ・ ・ Controller X ・ ・ Compression refrigeration system Z ・ ・ Absorption refrigeration apparatus

Claims (8)

A generator (1) that operates in response to exhaust heat from an engine (26 ) that drives the compression refrigeration system (X) , a condenser (2), and an evaporator (3) that temporarily evaporates refrigerant. An exhaust heat driven absorption refrigeration apparatus comprising a falling liquid film type absorber (4) and an air-cooled supercooler (6) for supercooling the absorbing solution entering the absorber (4) ,
While a refrigerant tank (14) and a refrigerant electromagnetic valve (10) are sequentially provided in the middle of the pipe (64 ) from the condenser (2) to the evaporator (3) ,
The absorber (4) temperature and / or the supercooled solution flowing into the By changing the flow rate, and controls the refrigeration capacity of the absorption type refrigerating apparatus to increase or decrease the capacity of the absorber (4) ,
When the temperature of the fluid to be cooled at the outlet of the evaporator (3) becomes equal to or lower than a target temperature calculated based on the outside air temperature and the condensation temperature of the compression refrigeration apparatus (X) , the absorber (4 ) to a temperature in the supercooled solution to flow in and / or by changing the flow rate at the same time performs the control of reducing the refrigerant absorption capacity of the absorber (4), the evaporator the refrigerant solenoid valve (10) is closed Reducing the amount of refrigerant flowing into the condenser (3) to reduce the refrigeration capacity of the absorption refrigeration apparatus, and accumulating refrigerant from the condenser (2) in the refrigerant tank (14) ,
When the temperature of the cooling fluid at the outlet of the evaporator (3) is equal to or above the target temperature, the absorber temperature and / or the supercooled solution flowing into (4) by changing the flow amount The refrigerant absorption capacity of the absorber (4) is increased, and at the same time, the refrigerant electromagnetic valve (10) is opened, and the refrigerant stored in the refrigerant tank (14) is caused to flow into the evaporator (3) to flow the refrigerant. It performs control for increasing the cooling capacity of the absorption refrigerating apparatus by increasing,
The operation / stop of the absorption refrigeration system is controlled by the solution temperature of the generator (1).
Even if the engine (26) is in a stopped state, if the solution temperature is equal to or higher than a predetermined temperature and the refrigerant storage capacity of the refrigerant tank (14) has a margin, the refrigerant electromagnetic valve (10) is closed, Operate the absorption refrigeration system until the refrigerant tank (14) is full, or operate only the solution pump (9) for allowing the absorbed dilute solution from the absorber (4) to flow into the generator (1),
If the solution temperature of the generator (1) is equal to or lower than the predetermined temperature, the operation of the absorption refrigeration system is stopped or the solution pump ( 9) Stopping the operation of 9) . Wherein the target temperature, the refrigerant solenoid valve that was the same temperature or different temperatures with the target temperature in the case of the closed and open (10) at which a closing said refrigerant solenoid valve (10) from the open The absorption refrigeration apparatus according to claim 1. In the refrigerant tank (14) provided with a weir (14a), together with the-flowed Yue the weir (14a) to flow the refrigerant to the evaporator (3), the evaporator by opening and closing the refrigerant solenoid valve (10) The absorption refrigeration apparatus according to claim 1 or 2 , wherein the refrigerant flow rate to (3) is increased or decreased. The surplus refrigerant after the refrigerant tank (14) is full is allowed to flow into the lower part of the evaporator (3) or directly into the dilute solution reservoir (16) of the absorber (4). absorption refrigerating apparatus according to claim 1, 2 or 3 wherein. Claim 1 and 2 to increase or decrease control of the flow rate of refrigerant flowing from the refrigerant tank (14) the evaporator to (3), and wherein the row Ukoto by the opening and closing of the refrigerant solenoid valve (10), 3 also 4 is an absorption refrigeration apparatus according to 4 . Controlling the refrigerating capacity by changing the temperature of the supercooled solution flowing into the absorber (4) by the start / stop of the fan (7) provided in the air-cooled supercooler (6) or the increase / decrease of the air volume. claim 1, 2, 3, the absorption refrigerating apparatus 4 or 5, wherein. The air subcooler (6) the flow rate adjusting valve provided on the inlet side or the outlet side of (11) or (12) by refrigerating capacity by varying the flow rate of the supercooling solution flowing into the absorber (4) claim 1, 2, 3, characterized in that to control, absorption refrigerating apparatus 4 or 5, wherein. A dilute solution from the absorber (4) that has absorbed the refrigerant vapor, and a concentrated solution that generates refrigerant vapor in the generator (1) and has a temperature lowered by heat exchange in the solution heat exchanger (5) . claim 1, 2, 3, characterized in that to control the refrigeration capacity by increasing or decreasing the flow rate of the mixed solution a solution pump for sucking and discharging (9), an absorption type refrigerating apparatus 4 or 5, wherein.

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