JPH0749896B2 - Cold temperature switching absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention provides a heated fluid having a temperature higher than that of a heat source fluid such as hot waste water and a cooled fluid having a temperature lower than that of a cooling fluid such as cooling water. The present invention relates to a cold / temperature switching type absorption refrigerating machine that can be generated by the above equipment.

(B) Conventional technology As the conventional technology of the above-mentioned cold / temperature switching type absorption refrigerator,
A pump and a bypass with a valve are inserted in parallel in the solution path connecting the generator and the absorber, and a bypass with a pump and a valve are inserted in parallel in the refrigerant path connecting the condenser and the evaporator, There is one (for example, Japanese Patent Publication No. 58-25947) in which the pump circuit and the bypass circuit are selectively switched to switch the pressure level between the generator / condenser group and the absorber / evaporator group.

(C) Problems to be Solved by the Invention In the above-mentioned conventional device, the piping is complicated because a bypass circuit with a valve is used, and a closed valve, a stopped pump, and their absorption There is a problem that the flow path is likely to be clogged due to the crystallization of the absorbing liquid remaining in the liquid circuit, which tends to hinder the smooth switching of the cold temperature operation. In addition, the temperature level of hot wastewater differs depending on the type of waste heat source, and the pressure difference between the generator / condenser group and the absorber / evaporator group also changes accordingly. There is also a problem that it is necessary to select or replace a pump having an appropriate discharge pressure according to the type.

In view of these problems, the present invention eliminates the need to select the pump according to the type of the heat source and the switching of the absorption liquid flow path for each switching of the cooling / heating operation, and to provide the absorption refrigerating machine capable of easily switching the cooling / heating operation. It is intended to be provided.

(D) Means for Solving the Problems The present invention provides, as means for solving the above problems, in a cold-temperature switching absorption refrigerator of the type described above, a dilute absorbent flow passage,
Discharge pressure variable pumps are installed in the concentrated absorption liquid flow path and the refrigerant liquid flow path from the condenser to the evaporator, and the high and low discharge pressures of these pumps are switched, and the generator / condenser group and the evaporator /
It is characterized in that the pressure of the absorber group is switched between high and low.

(E) Operation In the cold / temperature switching type absorption refrigerator of the present invention, the saturated vapor pressure in the evaporator / absorber is made lower than that in the generator / condenser, and the discharge of the pump for the diluted absorbing liquid is made. Increase the pressure,
By lowering the discharge pressure of the pump for the concentrated absorbing liquid and the pump for the refrigerant liquid to circulate the refrigerant and the absorber, the absorption refrigerating action is exerted, and like the conventional one, the cooling fluid of the absorber is more effective. Cold level cooled fluid is obtained from the evaporator. Conversely, the saturated vapor pressure in the generator / condenser is adjusted to the evaporator /
Lower the pressure in the absorber, increase the discharge pressure of the pump for the concentrated absorbing liquid and the pump for the refrigerant liquid, and lower the discharge pressure of the pump for the dilute absorbing liquid to circulate the refrigerant and the absorbing liquid. As a result, the absorption heat pump action is exerted, and the fluid to be heated at a higher temperature level than the heat source fluid supplied to the generator or the evaporator is obtained from the absorber. Moreover, since it is not necessary to switch the absorption liquid flow path, the absorption liquid crystal unlike the conventional one is not generated, and the switching of the cold temperature operation can be smoothly performed.

And also, in the cold temperature switching type absorption refrigerator of the present invention,
Even if the temperature level of the heat source fluid, cooling fluid, etc. is different due to the difference in the installation location and operation time, and there is a difference in the pressure difference between the generator / condenser group and the evaporator / absorber group, this difference Since there is also a function that can change the pump discharge pressure, for example, compared to the conventional cold-temperature switching absorption refrigerator that requires selection and replacement of the pump for each type of waste heat source, it keeps smooth circulation of the refrigerant and the absorption liquid easily. be able to.

(F) Example FIG. 1 is a schematic constitutional explanatory view showing an example of the cold temperature switching type absorption refrigerator according to the present invention. In FIG. 1, the generator (G) and the condenser (C) are formed in the body (1) to form a generator / condenser group having substantially the same internal pressure. The evaporator (E) and the absorber (A) are connected by a duct (2) to form an evaporator / condenser group having almost the same internal pressure. (3) and (4) are pipe lines for the dilute absorbing liquid from the absorber (A) to the generator (G) via the solution heat exchanger (X), and (5) and (6) are generated. It is a pipe line for the concentrated absorbing liquid from the vessel (G) to the absorber (A) via the solution heat exchanger (X). (7) is a refrigerant liquid conduit from the condenser (C) to the evaporator (E), and (8) is a refrigerant liquid reflux conduit.

Then, the discharge pressure variable pumps (P _L ), (P _H ), (P _H ), (P _H ), and (P _H ) are respectively provided in the dilute absorbent liquid conduit (3), the concentrated absorbent liquid conduit (5), and the refrigerant liquid conduit (7). P _R ) has been deployed. Further, (P) is a pump arranged in the refrigerant liquid recirculation pipe line (8).

(9) is a heater of the generator (G), through which steam or hot water as a heat source fluid is circulated. Reference numeral (10) is a heat exchanger of the absorber (A), through which cooling water or the like as a cooling fluid is circulated during the cooling cycle, while hot water or the like as a fluid to be heated is circulated during the heating cycle. (11) is a cooler for the condenser (C), through which cooling water or the like as a cooling fluid flows. Also (12)
Is a heat exchanger of the evaporator (E), through which cold water as a fluid to be cooled is circulated during a cooling cycle and hot water as a heat source fluid is circulated during a heating cycle.

Next, an example of the operation of the cold temperature switching type absorption refrigerating machine (hereinafter referred to as this machine) configured as described above will be described.

During the cooling cycle, high-temperature steam or hot water is supplied to the heater (9), cooling water is supplied to the heat exchanger (10) and the cooler (11), and heat exchange of the evaporator (E) is performed. Cold water as a fluid to be cooled is caused to flow through the vessel (12) to set the discharge pressure of the pump (P _R ) and the pump (P _H ) to a low pressure close to, for example, zero, while the discharge pressure of the pump (P _L ) is set to, for example, a few. Set the pressure to about 100 mmHg and operate this machine.
By performing such an operation, an absorption refrigeration cycle similar to that of a conventional absorption refrigeration machine is generated to exert a refrigerating action, and low-temperature cold water for cooling or other uses is obtained from the outlet of the heat exchanger (12). . The absorption refrigeration cycle at this time is a clockwise rotation cycle as shown in Fig. 2.
The pressure P _E of the absorber group is kept lower than the pressure P _C of the generator / condenser group.

During the heating cycle, the heater (9) and the heat exchanger (12) are supplied with a low-temperature level heat source fluid such as waste hot water and waste steam, and the cooling water is supplied to the cooler (11) and is absorbed. heat exchanger vessel (a) (10) to the flow of water as heated fluid, a pump (P _R) and a pump while setting the discharge pressure for example at a pressure of about several hundred mmHg of (P _H), the pump ( set the discharge pressure to a low pressure close to zero e.g. P _L) to operate the machine. By operating in this way, a counterclockwise absorption heat pump cycle as shown in FIG. 3 is generated, and the pressure P _C of the generator / condenser group is higher than the pressure P _E of the evaporator / absorber group. Kept low. In this cycle, the refrigerant liquid of the low pressure side condenser (C) is fed to the pump evaporator through refrigerant liquid conduit (7) by (P _R) (E), the heat exchanger (12) Of the heat source fluid evaporates and the evaporated refrigerant enters the absorber (A) via the duct (2). Furthermore, the concentrated absorption fluid conduit with concentrated absorption liquid pump from the generator _{(G) (P H) (} 5), (6)
Through the solution heat exchanger (X) to the absorber (A), where the refrigerant vapor is absorbed. At that time, absorber (A)
Since the internal pressure P _{E of} is maintained at about several hundred mmHg, the absorption liquid is heated to a temperature corresponding to the boiling point rise by the absorption heat and becomes higher in temperature than the heat source fluid described above, and the absorption liquid that has become high in temperature is the heat exchanger. The water in (12) is heated to raise the temperature. Therefore, a heated fluid having a higher temperature than the heat source fluid supplied to the generator (G) and the evaporator (E) can be obtained from the outlet of the heat exchanger (12). On the other hand, a dilute absorbent solution which has absorbed the refrigerant dilute absorbent liquid conduit (3), flows to (4) through the pump (P _L), the solution heat exchanger (X) generator via (G), wherein Is heated by the heat source fluid of the heater (9) and concentrated while generating steam. Then, the concentrated absorption liquid is pumped (P _H ).
Is again sent to the absorber (A). Also, the refrigerant vapor generated in the generator (A) is cooled by the condenser (C) cooler (1
Is condensed with cooled by the cooling water in 1), liquefied refrigerant is sent to the evaporator (E) again by a pump (P _R). The above-described absorption heat pump cycle is generated by repeating such circulation of the refrigerant and the absorption liquid. In this cycle, when the dilute absorption liquid can flow through the pipe lines (3) and (5) due to the pressure difference between the absorber (A) and the generator (G) or the liquid head, the pump (P
_L ) is sufficient if it plays the role of passing the diluted absorbent,
The discharge pressure may be set near zero. Further, when the temperature level of the heat source fluid supplied to the generator (G) or the evaporator (E) or the cooling fluid supplied to the condenser (C) varies depending on the operation time of the machine or the installation location, the generator in operation. - since the condenser group evaporator-absorber pressure difference also becomes different between the groups, the unit discharge pressure variable pump operation in time and location for each of the _{(P R), (P H} ), (P L) It is sufficient to set the discharge pressure of. Therefore, in this machine, there is no need to replace the pump at each operation time or each installation location. In the actual design, the pump discharge pressure is set in consideration of the pressure difference, the flow resistance of the liquid flow path, and the liquid head. By properly setting the pump discharge pressure, the smooth circulation of the refrigerant liquid and the absorbing liquid can be easily maintained, and the uneven distribution of these liquids in a part of the main unit can be prevented.

(G) Effect of the Invention As described above, the present invention is directed to the generator / condenser group and the evaporator /
By switching the pressure of the absorber group and the discharge pressure of the refrigerant liquid pump, the concentrated absorbent liquid pump, and the diluted absorbent liquid pump, the temperature of one absorption refrigerator is higher than that of the heat source fluid. In addition to the effect that the fluid and the fluid to be cooled having a temperature lower than that of the cooling fluid can be taken out alternately, the absorption liquid channel is switched to switch the cooling temperature to the cooling temperature, so that the crystal of the liquid in the unused channel is likely to occur. Compared with other things, it brings the effect that switching between cold and hot can be done smoothly and easily.
By setting the discharge pressure of the pump according to the pressure level between the condenser group and the evaporator / absorber group, the cold-temperature switching absorption refrigerator has the effect of easily maintaining smooth circulation of the refrigerant and the absorbing liquid. In addition, it has a practical value such that it is possible to omit the trouble of replacing the pump according to the difference in the pressure level in the device due to the difference in the installation area and the operation time.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an embodiment of a cold / heat switching type absorption refrigerator according to the present invention, and FIG. 2 is an absorption refrigeration cycle diagram during the cooling cycle of the embodiment shown in FIG. Yes, FIG. 3 is also an absorption heat pump cycle diagram during the heating cycle. (G) ... Generator, (C) ... Condenser, (E) ... Evaporator,
(A) ... Absorber, (X) ... Solution heat exchanger, (2) ... Duct, (3), (4), (5), (6), (7), (8)
... pipe, (9) ... heater, (10) ... heat exchanger, (11) ...
Cooler, (12) ... Heat exchanger, (P _R ), (P _H ), (P
_L ) ... Discharge pressure variable pump.

Claims (1)

[Claims] Claim: What is claimed is: 1. A generator, a condenser, an evaporator, an absorber and a solution heat exchanger are connected by piping to form a circulation path for a refrigerant and an absorption liquid, and a refrigerant liquid flow path and an absorption from the condenser to the evaporator. A variable discharge pressure pump is installed in each of the dilute absorption liquid flow path from the generator to the generator and the concentrated absorption liquid flow path from the generator to the absorber, and the discharge pressure of these pumps is switched between high and low, and the generator / condenser A cold / temperature switching type absorption refrigerating machine, which is configured to switch between high and low pressures between a group and an evaporator / absorber group.