JPH0830631B2 - 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 a conventional technology of the above-mentioned cold / temperature switching type absorption refrigerator, a bypass with a pump and a valve is inserted in parallel in the solution path connecting the generator and the absorber, and the condenser and the evaporation are also connected. Insert a pump and a bypass with a valve in parallel in the refrigerant path that connects the reactor, and selectively switch the pump circuit and bypass circuit to switch the pressure level between the generator / condenser group and the absorber / evaporator group. (For example, Japanese Examined Patent Publication Sho 58-25947)
Issue gazette).

(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 a pump according to the type of heat source and the switching of the absorption liquid path for each switching of the cold temperature operation, and to provide an absorption refrigerator that can easily switch the cold temperature operation. It is intended for.

(D) Means for Solving Problems As a means for solving the above problems, the present invention provides a cold absorption type absorption refrigerator having the above-mentioned type, which includes a dilute absorption liquid path, a concentrated absorption liquid path, and a condenser. Discharge variable pumps are installed in the refrigerant liquid path to the evaporator, and the discharge pressure of these pumps is switched between high and low, and at the same time, the heat source water that flows to the heat exchangers of the generator / condenser group and the evaporator / absorber group is external. It is characterized in that the temperature level of the fluid is changed to switch the pressure level between them.

(E) Action In the cold / temperature switching absorption refrigerator of the present invention, the evaporator /
The saturated vapor pressure in the absorber should be lower than that in the generator / condenser, and the discharge pressure of the pump for dilute absorbing liquid should be increased to the discharge pressure of the pump for concentrated absorbing liquid and the pump for refrigerant liquid. By lowering the temperature and circulating the refrigerant and the absorbing liquid, the absorption refrigerating action is exerted, and the cooled fluid at a lower temperature level than the cooling fluid of the absorber is obtained from the evaporator as in the conventional case. On the contrary, the saturated vapor pressure in the generator / condenser is made lower than that in the evaporator / absorber, and the discharge pressure of the pump for the concentrated absorbing liquid and the pump for the refrigerant liquid is increased to reduce the diluted absorbing liquid. The discharge pressure of the pump for pump is lowered to circulate the refrigerant and the absorbing liquid, so that the absorption heat pump function is exerted, and the heated fluid at a higher temperature level than the heat source fluid supplied to the generator or the evaporator is obtained from the absorber. To be 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.

Further, in the cold / heat switching type absorption refrigerator of the present invention, the temperature levels of the heat source fluid, the cooling fluid, etc. are different due to the difference in the installation location and the operation time, and the generator / condenser group and the evaporator / absorber group are different. Even if there is a difference in pressure difference between
Since there is also a function that can change the pump discharge pressure according to this difference, smooth circulation of refrigerant and absorption liquid is possible compared to conventional cold-temperature switching absorption refrigerators that require selection and replacement of pumps for each type of waste heat source, for example. It can be kept simple.

(F) Embodiment FIG. 1 is a schematic configuration explanatory view showing an embodiment of a 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 absorption liquid pipe (3), the concentrated absorption liquid pipe (5), and the refrigerant liquid pipe (7). _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. That is, the temperature level of the fluid flowing through these heat exchangers can be changed between the cooling cycle and the heating cycle.

FIG. 2 is a system explanatory view of an external fluid path showing one specific example of means for varying the temperature level of the fluid flowing from the outside to these heat exchangers, and is the same as the component equipment shown in FIG. The symbol is attached.

In FIG. _{2, (B), (U C} ), (C T), (W H),
(U _H ) are a boiler, a cooling load side unit, a cooling tower, a waste heat source, and a heating load side unit, respectively (V ₁ ) ~
(V ₈ ) is a three-way valve. Further, (P ₁ ) to (P ₄ ) are pumps. The flow paths of the three-way valves (V ₁ ) to (V ₈ ) are switched so that the fluid paths are switched. That is, the hot water circuit consists of a boiler (B) and a pipeline (1
3), pump (P ₁ ), pipeline (14), three-way valve (V ₁ ), pipeline (15), heater (9), pipeline (16), three-way valve (V ₂ ), pipeline ( consists of 17), the cold water circuit cooling load-side unit (U _C), the conduit (18), a pump (P _2), the conduit (19), the three-way valve (V _3), the conduit (20), heat Exchanger (12), pipeline (21),
It consists of a three-way valve (V ₄ ) and a pipe (22), while the waste hot water route is a waste heat source (W _H ), pipes (23) and (24), a three-way valve (V ₂ ) and a pipe (16). ), Heater (9), pipeline (15), three-way valve (V ₁ ), pipeline (25) and waste heat source ( _WH ), pipeline (23),
(26), three-way valve (V _4), pipe (21), heat exchanger (12, pipe (20), the three-way valve (V _3), is constructed out with the conduit (27). In addition, The cooling water circuit is a cooling tower (C _T ), pipe (28), pump (P ₃ ), pipe (29), cooler (11), pipe (30),
Three-way valve (V _5), the conduit (31), three-way valve (V _6), the conduit (3
2), heat exchanger (10), the conduit (33), the three-way valve (V _7), the conduit (34), the three-way valve (V _8), the conduit (35) and the cooling tower (C _T),
Conduit (28), a pump (P _3), the conduit (29), a cooler (1
1), pipeline (30), three-way valve (V ₅ ), pipeline (36), three-way valve (V ₈ ) and pipeline (35), while the hot water circuit is the unit on the heating load side ( U _H ), pipeline (37), (38), three-way valve (V ₆ ), pipeline (32), heat exchanger (10), pipeline (33),
It is composed of a three-way valve (V ₇ ) and a conduit (39).

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, hot water of 100 ° C. or higher is supplied to the heater (9), cooling water from the cooling tower (C _T ) is supplied to the heat exchanger (10) and the cooler (11), and , Cold water as a fluid to be cooled is caused to flow through the heat exchanger (12) of the evaporator (E), and the discharge pressure of the pump (P _R ) and the pump (P _H ) is set to a low pressure close to, for example, zero, while the pump ( by setting the discharge pressure for example at a pressure of about several hundred mmHg of P _L) to operate the 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.
The pressure P _E of the evaporator / absorber group is the pressure P _C of the generator / condenser group
Kept lower than.

During the heating cycle, the flow paths of the three-way valves (V ₁ ) to (V ₈ ) are switched and the heater (9) and the heat exchanger (12) are connected to each other.
Supplying waste hot water at a temperature level of about 60 ° C to 60 ° C and supplying cooling water from the cooling tower (C _T ) to the cooler (11),
At the same time, water as a fluid to be heated is caused to flow through the heat exchanger (10) of the absorber (A), and the discharge pressure of the pump (P _R ) and the pump (P _H ) is set to a pressure of, for example, several hundred mmHg. , Set the discharge pressure of the pump (P _L ) to a low pressure near zero, for example, and operate the machine. By operating in this way, a counterclockwise absorption heat pump cycle as shown in Fig. 4 is generated, and the pressure P _C of the generator / condenser group is lower than the pressure P _E of the evaporator / absorber group. To be kept. In this cycle, the refrigerant liquid in the low pressure side condenser (C) is sent to the evaporator (E) through the refrigerant liquid pipe (7) by the pump (P _R ),
The heat source fluid of the heat exchanger (12) heats and evaporates, and the evaporated refrigerant enters the absorber (A) via the duct (2). Also, the concentrated absorbent from the generator (G) is pumped (P _H ).
Is sent to the absorber (A) via the solution heat exchanger (X) through the concentrated absorbent liquid pipes (5) and (6), where the refrigerant vapor is absorbed. At that time, the internal pressure P _E of the absorber (A) is several hundred mm
Since it is maintained at about Hg, the absorption heat heats the absorption liquid to a temperature equivalent to the boiling point rise and becomes higher than the heat source fluid described above, and the high temperature absorption liquid causes the water in the heat exchanger (12) to Heat 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, dilute absorbent solution absorbs the refrigerant dilute absorbent liquid conduit (3), flows to (4) through the pump (P _L), the solution heat exchanger (X) generator via (G), Here, it is heated by the heat source fluid of the heater (9) and is condensed while generating steam. The concentrated absorption liquid is sent to the pump (P _H) again by the absorber (A). Further, the refrigerant vapor generated in the generator (A) is cooled and condensed by the cooling water in the cooler (11) of the condenser (C), and the liquefied refrigerant is again pumped by the pump (P _R ). ) Is sent to. The above-described absorption heat pump cycle is generated by repeating such circulation of the refrigerant and the absorption liquid. Note that, in this cycle, the conduit (3) by pressure difference or liquid head between the dilute absorbent liquid absorber (A) and the generator (G), if may flow (5), a pump (P _L ) Is sufficient as long as it plays the role of passing the diluted absorbent, its discharge pressure may be set to 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 pressure difference between the condenser group and the evaporator / absorber group will also be different, the discharge variable pump (P _R ), (P _H ), (P _L ) Set the discharge pressure. 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.

Furthermore, in this machine, the means for varying the temperature level of the external fluid (cold water, hot water, waste hot water, cooling water, high temperature water, etc.) passing through the heat exchangers (9) to (12) is connected to these heat exchangers. It is not limited to the one that switches the connection with the external fluid conduit. For example, a device for connecting the heat exchangers (9) to (12) to the external fluid pipeline passing through the radiator or the heat exchanger, and adjusting the heat radiation ability of the radiator or the heat feeding ability of the heat exchanger. The variable means may be used as the variable means.

(G) Effect of the Invention As described above, the present invention changes the temperature level of the external fluid flowing to the generator / condenser group and the evaporator / absorber group to switch the pressure level between them, and at the same time for the refrigerant liquid. By switching between high and low discharge pressures of the pump, the concentrated absorbent pump, and the diluted absorbent pump, a single absorption refrigerator cools the heated fluid above the heat source fluid and the cooled fluid below the cooling fluid. In addition to the effect that the cooling liquid can be taken out alternately, the cooling liquid temperature can be switched smoothly and easily compared to the conventional one in which the liquid crystal in the unused flow channel is likely to occur because the cooling liquid temperature is switched by switching the absorption liquid flow channel. Bring the effect
By setting the discharge pressure of the pump according to the pressure level of the generator / condenser group and the evaporator / absorber group, the effect of being able to easily maintain the smooth circulation of the refrigerant and the absorbing liquid is the cold / temperature switching type absorption refrigeration. It has a practical value in that it eliminates the trouble of replacing the pump according to the difference in the pressure level in the equipment 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 a fluid path showing a specific example of an external fluid path provided in the absorption refrigerator of FIG. 3 is an absorption refrigeration cycle diagram during the cooling cycle of the absorption refrigerator shown in FIG. 2, and FIG. 4 is 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) ... Pipeline, (9) ... Heater, (10) ...
… Heat exchanger, (11) …… Cooler, (12) …… Heat exchanger,
(P _R ), (P _H ), (P _L ) ... Discharge pressure variable pump,
(P ₁ ), (P ₂ ), (P ₃ ), (P ₄ ) ... Pump, (B) ...
… Boiler, (C _T ) …… Cooling tower, (U _C ) …… Cooling load side unit, (U _H ) …… Heating load side unit, (W _H ) ……
Waste heat source, (13) to (39) …… Pipe, (V ₁ ) to (V ₈ ) ……
Three-way valve.

Claims (1)

[Claims] 1. A heat exchanger provided with a generator, a condenser, an absorber, an evaporator, and a refrigerant vapor path connecting these devices, a refrigerant liquid path, a dilute absorption liquid path, and a concentrated absorption liquid path, and which is built in the equipment. In an absorption chiller equipped with an external fluid path for passing fluid from outside the machine, the pressure between the generator / condenser group and the evaporator / absorber group is adjusted by means of varying the temperature level of the fluid flowing in the external fluid path. The discharge pressure of the variable discharge pressure pump, which is installed in the refrigerant liquid path from the condenser to the evaporator, the dilute absorption liquid path, and the concentrated absorption liquid path, is switched between high and low to condense from the heat exchanger of the evaporator. Temperature switching characterized by selectively extracting either a cooled fluid whose temperature is lower than that of the cooling fluid of the evaporator or a heated fluid whose temperature is higher than that of the heat source fluid of the evaporator from the heat exchanger of the absorber Type absorption refrigerator.