JP2645824B2 - Double effect absorption refrigerator - Google Patents

Description

The present invention relates to an improvement in a double effect absorption refrigerator having a pump in a concentrated solution flow path.

(B) Conventional technology As a conventional technology of the above-described double effect absorption refrigerator,
For example, as shown in JP-B-53-36174, the discharge side of the dilute solution pump and the suction side of the concentrated solution pump are connected by a pipe with a control valve, and the opening of the control valve of this pipe is And a controller for adjusting the temperature of the evaporator by a signal from a temperature detector of a chilled water outlet of the evaporator.

(C) Problems to be Solved by the Invention In the conventional double-effect absorption refrigerator described above, the concentrated solution flowing to the absorber is diluted with a dilute solution to reduce the refrigerant absorption capacity of the absorber at partial load. Although there is an advantage that the solution can be weakened to prevent overcooling, dilution of the concentrated solution with a dilute solution is limited, so that there is a problem that overcooling under a small load cannot be prevented.

The present invention has been made in view of the above problems, and has as its object to provide a double-effect absorption refrigerator capable of preventing overcooling even under a small load.

(D) Means for Solving the Problems The present invention solves the above-mentioned problems by using a signal from a chilled water outlet temperature detector of an evaporator in a double effect absorption refrigerator of the above-mentioned type to measure a concentrated solution. Controls the opening of the control valve of the line connecting the pump suction side and the dilute solution reservoir of the absorber, and switches the on / off valve of the refrigerant liquid blowing line connecting the dilute solution reservoir and the refrigerant liquid flow path Is performed.

(E) Function In the double effect absorption refrigerator of the present invention, the concentrated solution is diluted with the dilute solution and the refrigerant liquid at a small load when the temperature of the chilled water is apt to decrease, so that the refrigerant absorption capacity of the absorber is higher than that of the conventional one. The effect of weakening can be exhibited. For this reason, in the double effect absorption refrigerator of the present invention,
It is possible to further reduce the drop in the temperature of the chilled water at the time of a minute load, and it is possible to effectively prevent overcooling.

(F) Embodiment FIG. 1 is a schematic structural explanatory view showing an embodiment of a double effect absorption refrigerator according to the present invention. In FIG.
(1) is a high-temperature generator, (2) is a generating condenser composed of a low-temperature generator (3) and a condenser (4), (5) is an evaporator-absorber composed of an evaporator (6) and an absorber (7). , (8)
Is a low-temperature solution heat exchanger, (9) is a high-temperature solution heat exchanger, (P
_(LA ) is a dilute solution pump, (P _HA ) is a concentrated solution pump, (P
_R ) is a refrigerant liquid pump, which connects these devices with refrigerant lines (10) and (11), refrigerant liquid flowing down line (12), refrigerant liquid recirculating lines (13) and (14), Solution conduits (15), (16),
(17), (18), medium concentration solution line (19), (2
0) and a concentrated solution pipe line (21), (22), (23) connected to form a circulation path for the refrigerant [water] and the solution [lithium bromide aqueous solution].

(24) is a combustion heating chamber of the high-temperature generator (1), (25) is a heater of the low-temperature generator (3), (26) is a cooler of the condenser (4), and (27) is an evaporator (6). ), A heat exchanger (28), a cooler of an absorber (7), (29) a refrigerant distillation of an evaporator (6),
(30) is a solution reservoir of the absorber (7), (B) is a burner of the high-temperature generator (1), (31), (31) ... are combustion gas passages, (32) is a combustion gas exhaust passage, ( 33) and (34) are a fuel supply path and a combustion air supply path to the burner (B), respectively, and (35) and (36) are for cold and hot water connected to the heat exchanger (27). The pipelines (37), (38) and (39) are cooling water pipelines in which the coolers (28) and (26) are connected in series.
In addition, (P) and (F) are the ignition device and the blower of the burner (B), respectively, (40) is a refrigerant vapor line with a cold / hot switching valve (V _CHR ), and (41) is a cold / hot switching valve (V _CHA). ) Is for the solution.

(42) is a solution circulation line connecting the solution reservoir (30) of the absorber (7) and the concentrated solution pump ( _PHA ) suction side pipeline (21). Is equipped with a flow control valve (V _A ). (43) is a refrigerant liquid recirculation line (14) on the refrigerant liquid pump (P _R ) discharge side and a solution reservoir (30) of the suction device (7).
And an on-off valve (V).

(V _F ) is a fuel control valve provided in the fuel supply path (33),
(D) is a damper provided in the fuel air supply path (34), and this damper is linked to a fuel control valve (V _F ) to adjust the opening. Further, a temperature detector provided in (S _T) is hot and cold water conduit (36).

(C) receives the signal from the temperature detector (S _T ) and receives the opening control signal for the fuel control valve (V _F ) and the flow control valve (V _A )
The controller sends a signal for controlling the opening degree, a signal for switching the opening and closing of the on-off valve (V), and a signal for starting and stopping the pump for refrigerant liquid (P _R ). And an electric circuit such as a temperature comparison unit and a signal input / output unit that compares the level of the temperature set by this with the temperature sensed by the temperature detector.

Next, an operation example of the double effect absorption refrigerator (hereinafter, referred to as this machine) configured as described above will be described with reference to FIG. 2 to FIG.

FIG. 2 is a diagram showing the relationship between the opening degree of the flow control valve (V _A ) and the fuel control valve (V _F ) and the chilled water outlet temperature of the evaporator (6). FIG. 3 is a diagram showing the relationship between the switching operation of the on-off valve (V) and the chilled water outlet temperature.
The figure is a diagram showing the relationship between the coolant pump (P _R ) and the chilled water outlet temperature.

In the chilled water discharge operation of the present apparatus, when the chilled water outlet temperature is a rated value (for example, 7 ° C.), the controller (C) which receives a signal from the temperature detector (S _T ) receives a solution flow control valve (V). All close signal of _a), fully open signal of the fuel control valve (V _F), the operation of the actuation signal is sent rating of all closing signal and the coolant pump (P _R) of the opening and closing valve for refrigerant blow (V) Done. Also, when the chilled water outlet temperature exceeds the rated value, the same signal as in the rated operation is transmitted from the controller (C) and the operation is performed (see FIGS. 2 to 4).

Then, when the load decreases and the chilled water outlet temperature falls below the rated value, the controller (C) receiving the signal from the temperature detector ( _ST ), as shown in FIG. The opening of the fuel flow control valve (V _F ) is increased while the opening of the solution flow control valve (V _A ) is increased in proportion to the outlet temperature. In addition,
The opening of the damper (D) is reduced in conjunction with the fuel control valve (V _F ).

With such control, the amount of the dilute solution mixed into the concentrated solution sprayed on the cooler (28) of the absorber (7), in other words, the concentration of the sprayed concentrated solution and the heating of the high-temperature generator (1) Since the amount and the load are simultaneously adjusted according to the load, the followability of the refrigeration capacity control at the time of the partial load is improved.

When the load further decreases and the chilled water outlet temperature reaches the low-temperature set value (for example, 5 ° C.), the fuel control valve (V _F ) is fully closed, the flow control valve (V _A ) is fully opened, and FIG. As shown in (1), the controller (C) sends a fully open signal of the on-off valve (V) for blowing the refrigerant liquid, and the refrigerant liquid is pumped into the solution reservoir (30) of the absorber (7) by the refrigerant liquid pump (P _R ). Blown into a dilute solution of
This dilute solution is diluted. Then, the concentrated solution is dispersed in the absorber (7) while being diluted by the diluted diluted solution, and the refrigerant absorption capacity is further weakened, so that the follow-up performance of the refrigeration capacity control under a small load is improved.

Further, when the chilled water outlet temperature falls to the lower limit set value (for example, 4.5 ° C.) due to a further reduction in load or a drop in the temperature of the cooling water supplied to the unit, as shown in FIG.
The controller (C) sends an operation stop signal of the refrigerant liquid pump (P _R ), and the spraying of the refrigerant liquid to the heat exchanger (27) of the evaporator (6) is cut off to stop the vaporization of the refrigerant. Have been. As a result, an excessive temperature drop of the cold water at the time of a minute load, that is, excessive cooling of the load side is prevented, and freezing of the cold water is also prevented.

On the other hand, if the chilled water outlet temperature starts to increase due to the decrease in the load, the controller (C) switches the refrigerant liquid pump (P _R ) when the chilled water outlet temperature returns to the low temperature set value [5 ° C.]. An operation return signal, a control signal for increasing the opening of the fuel control valve (V _F ) and a control signal for decreasing the opening of the solution flow control valve (V _A ), and the chilled water outlet temperature is set to a low temperature set value [ When the temperature rises to a value [5.5 ° C.] higher than the predetermined temperature [0.5 ° C.] than the temperature [5 ° C.], the controller (C) sends a signal to close the on-off valve (V) for blowing the refrigerant liquid, and When the outlet temperature returns to the rated value, the controller (C) issues a fully open signal of the fuel control valve (V _F ) and a fully closed signal of the flow control valve (V _A ) to resume the rated operation of the machine. .

When taking out hot water from the machine, the cold / hot switching valves (V _CHR ) and (V _CHR ) are fully opened while the on-off valve (V) and the flow control valve (V _A ) are fully closed, and the refrigerant liquid pump ( While the operation of the P _R ) and the concentrated solution pump (P _HA ) is stopped, the dilute solution pump (P _LA ) is activated, and the supply of the cooling water to the absorber (7) and the condenser (4) is cut off. And temperature detector (S _T )
Is operated while controlling the opening degree of the fuel control valve (V _F ) according to the hot water load through the controller (C) in response to the signal (1). In addition, when switching from the cold water discharging operation to the hot water discharging operation of the present apparatus, the on-off valve (V) for blowing the refrigerant liquid may be opened to perform the solution dilution operation in advance, and then the operation may be shifted to the hot water discharging operation. .

Although not shown in the drawings, the refrigerant liquid in the condenser (4) may be blown into the solution in the solution reservoir (30).

(G) Effects of the Invention As described above, according to the present invention, the double effect absorption refrigerator has the effect of diluting the concentrated solution with the dilute solution and the refrigerant liquid to quickly weaken the refrigerant absorption capacity of the absorber. Therefore, the effect of improving the followability of the refrigeration capacity control when the load suddenly decreases and the effect of preventing overcooling can be provided to the double effect absorption refrigerator.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an embodiment of a double effect absorption refrigerator according to the present invention, FIG. 2 is a diagram illustrating the operation of a fuel control valve and a solution flow control valve, and FIG. FIG. 4 is an operation explanatory view of the on-off valve for blowing, and FIG. 4 is an operational explanatory view of the refrigerant liquid pump. (1) High temperature generator, (2) Low temperature generator, (4)
... condenser, (6) ... evaporator, (7) ... absorber,
(8), (9) ... Low temperature, high temperature solution heat exchanger, (P _R ) ...
… Refrigerant liquid pump, (P _LA ) …… Dilute solution pump,
(P _HA ) ... Pump for concentrated solution, (13), (14) ... Refrigerant liquid reflux pipe, (21), (22), (23) ... Pipe for concentrated solution, (27) ... ... heat exchanger, (28) ... cooler, (29) ...
... Refrigerant liquid reservoir, (30) ... Solution reservoir, (42) ... Solution distribution pipeline, (43) ... Refrigerant liquid blow pipeline, (C) ... Controller, ( _VA ) ... Flow control valve, (V _F ) …… Fuel control valve,
(V): On-off valve, (S _T ): Temperature detector.

Claims (1)

(57) [Claims] In a double effect absorption refrigerator having a concentrated solution pump provided in a concentrated solution flow path from a low temperature generator to a absorber through a low temperature solution heat exchanger, a suction side of the concentrated solution pump and an absorber are connected. Connects the solution reservoir of the evaporator with a pipe with a control valve, connects the refrigerant liquid flow path and the solution reservoir of the absorber with a refrigerant liquid blow pipe with an on-off valve, and senses the chilled water outlet temperature of the evaporator. A double-effect absorption refrigerator comprising a controller that controls the opening of the control valve and switches the opening and closing of the on-off valve in accordance with a signal from a detector that performs the operation.