JPH0355738B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a compression type refrigeration system that can improve the coefficient of performance of a compressor and can perform capacity control relatively easily. The principle of compression refrigeration equipment that uses condensable gas refrigerants such as fluorocarbon refrigerants as a heat medium has been fully clarified, and it seems that the basic technical problems in practical use have been improved, and the performance and efficiency have improved. We have reached the point where we cannot hope for any significant improvement over the current situation in these areas. What is common to this type of refrigeration equipment is that it is extremely common to use an unloading mechanism to control the capacity or to control the motor rotation speed, so it is relatively easy to use. There is a problem with the complicated equipment that leads to high costs, and it is currently impossible to improve the coefficient of performance other than by making mechanical improvements, as the development of new refrigerants is not progressing. Although these issues have been pointed out, the reality is that the current situation is complacent with no improvement measures in sight. In view of these circumstances, the present invention has been developed as a result of intensive studies to develop a new refrigeration system that has a different form from conventional compression refrigeration equipment. We have now supplied a refrigeration system that can be operated relatively easily, and in particular, a solution obtained by reacting an absorbent with refrigerant vapor is heated by introducing low-temperature heat into the vessel, and the solution is heated. A generator that generates refrigerant vapor, a compressor that compresses and pressurizes the generated refrigerant vapor, and reacts the compressed and pressurized high-pressure refrigerant vapor with the concentrated solution returned from the generator in the container, and converts the concentrated solution into the An absorber that absorbs high-pressure refrigerant vapor and extracts the reaction heat generated by this absorption to the outside; A solution circuit, a concentrated solution circuit having a pump interposed therein to send the concentrated solution from the generator to the absorber, and a heat source connected to both solution circuits to enable heat exchange between the dilute solution and the concentrated solution. It consists of an exchanger, and is characterized in that the steam heat in the generator can be used as a cold heat source, and the absorption reaction heat in the absorber can be used as a heat source. Furthermore, in addition to the above configuration, the present invention provides a condensing coil through which the low-temperature concentrated solution before flowing into the heat exchanger in the concentrated solution circuit can be circulated when necessary, and a high-temperature dilute solution in the dilute solution circuit before flowing into the heat exchanger. A solution concentration regulator having an evaporating coil that can be circulated when necessary for heat exchange inside the container is interposed in a refrigerant vapor pipe connecting the discharge port of the compressor and the inlet of the absorber. By providing this configuration, the solution concentration within the system can be adjusted, and the capacity of the refrigeration device can be adjusted as appropriate. Hereinafter, specific contents of the present invention will be further explained in detail with reference to the accompanying drawings. FIG. 1 is a circuit diagram of an apparatus according to the present invention, which includes a generator 1 having a solution dispersion nozzle 7 and a heat exchange coil 8 arranged vertically, and a gas phase section of the generator 1. It has a compressor 2, a solution dispersion nozzle 11, and a heat exchange coil 12 arranged vertically in the compressor 2, the suction port of which is connected to the outlet facing the open side through a low-pressure refrigerant vapor pipe 9, and facing the gas phase part. A high-pressure refrigerant vapor pipe 10 is connected to the inlet of the compressor 2, and a throttle valve 13 is provided in the middle of the absorber 3, and the absorber 3 is provided facing the liquid phase part. a dilute solution circuit 4 and a pump 1 for communicating the outlet of the generator 1 with the solution spraying nozzle 7 of the generator 1;
4 in the middle, and a concentrated solution circuit 5 for communicating the outlet provided in the generator 1 facing the liquid phase with the solution spraying nozzle 11 of the absorber 3, both solution circuits 4, 5, a heat exchanger 6 provided to enable heat exchange between a dilute solution and a concentrated solution, a condensing coil 16 and a steam coil 17 are housed in a vertical relationship in a container, and the container is A solution concentration regulator 15 interposed as a refrigerant vapor passage in the middle of the high-pressure refrigerant vapor pipe 10, a first flow rate control valve 18 interposed in a portion of the concentrated solution circuit 5 before flowing into the heat exchanger 6, and a dilute solution circuit. 4, a second flow rate control valve 19 interposed in a portion before flowing into the heat exchanger 6, and the first flow rate control valve 1
8, a pipe 20 that connects the inlet side of the condensation coil 16, a pipe 21 that connects the outlet side of the condensation coil 16 and the portion of the concentrated solution circuit 5 after passing through the heat exchanger 6; 2 flow rate control valve 19
It consists of a pipe 22 that connects the diversion port and the inlet side of the steam coil 17, and a pipe 23 that connects the outlet side of the evaporation coil 17 and the portion of the dilute solution circuit 4 after passing through the heat exchanger 6. A predetermined amount of a solution obtained by reacting the absorbent with refrigerant vapor (a specific example of this solution will be described later) is sealed in this closed circuit. Note that the first flow rate control valve 18 is a control valve for causing a part or all of the low temperature concentrated solution flowing out from the generator 1 to flow through the condensing coil 16, while the second flow rate control valve 19 is , is a control valve for causing a part or all of the high temperature dilute solution flowing out from the absorber 3 to flow to the evaporation coil 17. In the above device, when a dilute solution (a solution that has absorbed a large amount of refrigerant vapor) whose temperature has been lowered by heat exchange in a heat exchanger 6 is sprayed from the nozzle 7 in the generator 1, the heat exchange coil By exchanging heat with the water in the heat exchange coil 8 and being heated, refrigerant vapor is generated, and the water in the heat exchange coil 8 is cooled by the latent heat of evaporation at that time. This cooling vapor is sent to the compressor 2 via the low-pressure refrigerant vapor pipe 9, while the concentrated solution after the refrigerant vapor has been separated (a solution that absorbs a small amount of refrigerant vapor) is pumped 1
4. After passing through the heat exchanger 6 and increasing its temperature, it is sent to the solution spraying nozzle 11 of the absorber 3. After being compressed and pressurized, the refrigerant vapor sent to the compressor flows into the absorber 3 through the high-pressure refrigerant vapor pipe 10, and reacts with the concentrated solution sprayed from the solution spraying nozzle 11, turning into a concentrated solution. Upon absorption, the concentrated solution becomes a dilute solution. At this time, absorption reaction heat is generated, so heat is exchanged between the high temperature dilute solution and the water in the heat exchange coil 12 to lower the temperature of the dilute solution.
Hot water can be taken out from 2. After the dilute solution in the absorber 3 is depressurized by the throttle valve 13, it is further cooled by the heat exchanger 6 and sent to the solution spraying nozzle 7. As described above, by circulating the solution and generating and absorbing refrigerant vapor, the heat of evaporation in the generator 1 can be used as a cold heat source, and the heat of absorption reaction in the absorber 3 can be used as a heat source. , it becomes possible to operate a heat pump using a compressor. In the above-mentioned refrigeration system, the solutions that are the elements of the solution refrigeration cycle include a solution using ammonia as a refrigerant and sodium iodide as an absorbent, a solution using ammonia as a refrigerant and ammonium chloride as an absorbent, and a solution using ammonia as a refrigerant and ammonium chloride as an absorbent. Freon R-22, absorbent
A solution made using E181 (tetraethylene glycol dimethyl ether) and Freon R- as a refrigerant.
22. One of the solutions using DMF (dimethylformamide) as an absorbent is selected. The main feature of the present invention is that by performing heat pump operation in a solution refrigeration cycle using such a solution, the coefficient of performance can be improved compared to a compression refrigeration cycle using pure refrigerant. Reaction systems for which data are available regarding the possibility of improving the coefficient of performance, which is the expected benefit of
Regarding the reaction system, the coefficient of performance (heat ratio) and solution concentration of a waste heat recovery heat pump that raises the temperature of 32°C waste heat to 55°C and uses it are calculated as shown in the table below.

【table】

[Table] As is clear from the above theoretical calculations, the coefficient of performance is improved compared to conventional compression refrigeration equipment that uses pure refrigerant cycles such as ammonia and CFC R-22. This is because the latent heat of vaporization and the heat of reaction can be utilized, although the high-low pressure ratio increases and the required power of the compressor increases. Next, in the refrigeration system according to the present invention, when controlling the refrigeration capacity, it is naturally possible to control the capacity of the compressor 2 by using the unloading mechanism or by controlling the rotation speed. However, capacity control is possible by adjusting the solution concentration in the solution refrigerant system while continuing normal operation of the compressor 2. This control mode will be explained below based on FIG. 1. In this refrigeration system, if you want to control the capacity to a reduced side, for example, if you operate the flow control valve 18 in the direction in which the diversion port opens while the compressor 2 is operated at its normal capacity, the compressor 2 A part of the refrigerant vapor on the discharge side exchanges heat with the low-temperature concentrated solution flowing in the condensing coil 16 in the solution concentration regulator 15, condenses and liquefies, and is stored at the bottom of the vessel. As a result, the refrigerant content of the solution in the system decreases, and both the generated heat and absorbed heat decrease, reducing the capacity of the refrigeration system. On the other hand, when it is desired to increase the capacity, the compressor 2 is operated normally while the flow control valve 19 is operated in the direction in which the diversion port opens. As a result, the refrigerant liquid stored at the bottom of the solution concentration regulator 15 is heated by the high-temperature dilute solution flowing through the evaporation coil 17, and is evaporated and returned to the high-pressure refrigerant vapor pipe 10. and sent to the absorber 3. Therefore, the refrigerant content of the solution in the system increases, both the heat generated and the heat absorbed increase, and the capacity of the refrigeration system increases. By adjusting the solution concentration in the solution refrigerant system in this way, it is possible to increase or decrease the capacity of the compressor 2 while maintaining normal operation. The present invention has the structure and operation as described in detail above, and can be operated at a relatively low pressure in the system compared to a pure refrigerant cycle in which condensation and evaporation occur, thereby reducing equipment costs. It is possible to do so. Furthermore, although the high-to-low pressure ratio of the system increases and the power required for the compressor increases, the latent heat of vaporization and reaction heat can be used, so the coefficient of performance is improved. Furthermore, according to the present invention, the solution concentration in the system can be adjusted to be large or small by the action of the solution concentration regulator 15, thereby increasing or decreasing the device capacity, which is not only convenient in terms of handling, but also allows fine capacity control to be performed easily. However, its practical effects are significant. Therefore, the present invention can be applied to a heat transport system where waste heat is used with a slight temperature increase, or where heat is utilized at a remote location with almost no need for temperature increase. It is a refrigeration device.

[Brief explanation of drawings]

FIG. 1 is a device circuit diagram according to an example of the device of the present invention. 1... Generator, 2... Compressor, 3... Absorber,
4... Dilute solution circuit, 5... Concentrated solution circuit, 6... Heat exchanger, 13... Throttle valve, 14... Pump, 15
...Solution concentration regulator.

Claims (1)

[Claims] 1. A generator 1 that generates refrigerant vapor from the solution by heating a solution obtained by reacting an absorbent with refrigerant vapor by introducing low-temperature heat into the container, and a compressor 2 that compresses and pressurizes the generated refrigerant vapor. The compressed and pressurized high-pressure refrigerant vapor and the concentrated solution returned from the generator 1 are reacted in the container, and the concentrated solution absorbs the high-pressure refrigerant vapor, and the reaction heat generated by this absorption is absorbed. An absorber 3 to be taken out to the outside, a dilute solution circuit 4 having a throttle valve 13 or a pump interposed therein to send the dilute solution from the absorber 3 to the generator 1, and the generator 1.
A concentrated solution circuit 5 having a pump 14 interposed therein for sending the concentrated solution from the solution to the absorber 3, and connected to both the solution circuits 4 and 5 to enable heat exchange between the dilute solution and the concentrated solution. a condensing coil 16 through which the low-temperature concentrated solution before flowing into the heat exchanger 6 in the concentrated solution circuit 5 can be circulated when necessary, and a high-temperature dilute solution before flowing into the heat exchanger 6 in the dilute solution circuit 4 when necessary. From the solution concentration regulator 15, which is equipped with an evaporating coil 17 that can be circulated for heat exchange inside the container and is interposed in a refrigerant vapor pipe that connects the outlet of the compressor 2 and the inlet of the absorber 3. Therefore, the heat of evaporation in the generator 1 can be used as a cold heat source, and the heat of absorption reaction in the absorber 3 can be used as a heat source, and the capacity of the refrigeration system can be adjusted as appropriate by adjusting the concentration of the solution in the system. A compression type refrigeration device characterized by: