JPH0623627B2 - Cold water flow controller for absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a device for controlling the supply amount of cold water to an absorption refrigerator by controlling the discharge amount of pumps or the number of pumps (hereinafter referred to as this type of device). ) Regarding the improvement.

(B) Conventional technology As a conventional technology of this type of apparatus, for example, Japanese Patent Publication No. 53-
As disclosed in Japanese Patent No. 2216, at the time of 50% load, one of the two cooling water pumps is stopped, the operation of the refrigerant pump and the heating of the generator are temporarily stopped, and 2 It is known that one of the chilled water pumps is stopped to resume the operation of the refrigerant pump and the heating of the generator to maintain the low load operation of the absorption refrigerator.

(C) Problems to be solved by the invention In the above-mentioned conventional device of this type, when the load on the absorption refrigerator is suddenly changed from 100% to 50%, the heating of the generator is temporarily stopped to set the chilled water temperature to a predetermined level. Since one of the two cold water pumps is stopped after waiting for the rise of the cold water, it is possible to surely prevent the freezing of the cold water when the load suddenly decreases. However, while the operation of the refrigerant pump is temporarily stopped when the load suddenly decreases, the operation of the absorption liquid pump is continued and the refrigerant is absorbed by the absorber, so that, for example, a small amount of refrigerant that remains in the refrigerant spreader. The liquid or the liquid refrigerant in the upper layer of the liquid refrigerant reservoir of the evaporator may freeze. In this case, a safety device works to prevent overload and cavitation of the refrigerant pump,
Even if the cold water rises to a predetermined temperature, the operation of the refrigerant pump and the heating of the generator are not restored. Therefore, there is a problem that the operation of the absorption chiller remains stopped and the cold water temperature rises more than necessary.

Further, since the heating of the generator is temporarily interrupted, it takes a rise time to restart the operation, and there is a problem that the operation tends to be unstable.

The present invention prevents problems, such as refrigerant and cold water freezing, that occur easily when the cold water supply amount to the absorption refrigerator is sharply reduced by controlling the number of pumps and the discharge amount control, and stabilizes the operation of the absorption refrigerator. The purpose is to provide a device of this kind that can be continued.

(D) Means for solving the problem The present invention, as a means for solving the above problems, changes in the flow rate of the cold water flowing through the evaporator when the flow rate of the cold water supplied to the absorption refrigerator is sharply reduced. When a physical quantity such as refrigerant temperature or vapor pressure in the evaporator that changes in accordance with it reaches a set value, a controller that receives a signal from a detector that senses this physical quantity and issues an increase correction signal of the chilled water flow rate The configuration is provided for the device.

(E) Action According to this kind of device of the present invention, when the refrigerant liquid temperature or vapor pressure in the evaporator reaches a set value before excessive reduction, the flow rate of the cold water in the evaporator is corrected to increase and Since the absorption refrigerator has the function of increasing the temperature and its saturated vapor pressure again, it is possible to prevent freezing of the refrigerant and freezing of cold water.

And, compared with the conventional absorption refrigerator having this kind of device, the operation can be continued more stably.

(F) Embodiment FIG. 1 is a schematic configuration explanatory view showing an embodiment of this type of apparatus according to the present invention. In FIG. 1, (1) is a high temperature generator, (2) is a low temperature generator, (3) is a condenser, (4) is an evaporator,
(5) is an absorber, (6) and (7) are low-temperature and high-temperature solution heat exchangers, (P _R ) is a refrigerant liquid pump, and (P _A ) is an absorption liquid pump, through which the refrigerant flows. Pipes (8), (9), pipes (10) that flow down after the refrigerant, pipes (11), (12) that flow back the refrigerant liquid, pipes (13), (14) to which the dilute absorption liquid is sent, intermediate concentration Absorption liquid flow tube
(15), (16), the pipes (17), (18) through which the concentrated absorbing liquid flows, and the same refrigerant (water) and absorbing liquid (lithium bromide aqueous solution) as in the conventional double-effect absorption refrigerator are connected. A circuit is constructed.

(19) is a combustion heating chamber of the high temperature generator (1), (20), (20) ... are tubes for heating the absorbing liquid through which the combustion gas flows, and (21) is a low temperature generator.
(2) heater, (22) condenser (3) cooler, (23) evaporator
(4) is a water cooler, and (24) is a cooler of the absorber (5). (twenty five),
(26) is a water cooler (23) and a load side heat exchange unit (not shown)
This is a chilled water pipe that connects with and is equipped with a chilled water pump (P _W ) with a variable discharge rate. Also, (27), (28), (29)
Is a cooling water flow path in which coolers (24) and (22) are connected in series,
A cooling water pump (P _C ) with a variable discharge rate is provided in this flow path. Note that (30) in the fuel supply passage to the combustion heating chamber (19), This is provided a fuel control valve (V _F) is.

And (Scal) is a calorie detector that senses the cold water temperature and the cold water flow rate of each of the pipelines (25) and (26), and the cold water flow controller (C _W ) is used to send cold water by the signal of this calorie detector. The discharge amount of the cooling water pump (P _W ) is controlled and the discharge amount of the cooling water pump (P _C ) is controlled via the cooling water flow rate controller (C _C ). Further, (R _C ) is a cooling water flow controller (cooling water flow controller built into _CC , which is a signal of the liquid level detector (S _L ) provided in the high temperature generator (1). When the level sensed by the liquid level detector (S _L ) falls below the set value while receiving, the pump (P _C ) discharge amount reduced by the cooling water flow controller (C _C ) is returned to the original amount, for example. , the controller (C _C) is adapted to emit a command signal of the pump (P _C) discharge amount increase correction for. the cooling water flow rate regulator (R _C) in the high temperature generator (1) in A function of increasing and correcting the ejection amount according to the descending speed of the liquid surface may be provided.
When this function is provided, it is convenient to use a liquid level detector having a large number of electrodes having different lengths. Further, any one of the pressure detector (S _PC ), (S _PG ), and temperature detector (S _TC ) signals may be input to the cooling water flow rate regulator (R _C ). When any of these detectors is used, when the sensed physical quantity becomes higher than the set value, the regulator ( _RC ) to controller ( _CC )
Output the correction signal to.

Furthermore, (R _W) is in a cold water flow regulator incorporated in the coolant flow rate controller (C _W), the regulator, the evaporator (4)
While receiving the signal from the temperature detector (S _TR ) provided in the liquid reservoir (31) or the pressure detector (S _PE ) provided in the vapor phase part of the evaporator (4), the detected physical quantity falls below the set value. Then, the controller (C _W ) sends a command signal to the pump (P _W ) to increase the discharge amount.

In addition, (S _TW ) is a cold water temperature detector installed in the pipeline (26),
Opening of the temperature controller by the signal of the detector (T _C) via a fuel control valve (V _F) is adapted to be adjusted.

Next, the cold water flow rate control device configured as described above (hereinafter,
An operation example of this device) will be described together with the operation of the absorption refrigerator.

Now, during operation of the absorption chiller, for example, when the load is reduced from 100% to 50%, the refrigeration output of the absorption chiller becomes excessive with respect to the load, so the operation for balancing the refrigeration output with the load is first performed. Be started. That is, while the fuel control valve (V _F) is reduced to approximately half open from the fully open via the temperature controller (T _C) with a signal of a cold water temperature detector (S _TW), the discharge amount of chilled water pump (P _W) Is reduced to almost half of the rated value via the cold water flow controller (C _W ) by the calorie detector (Scal) signal, and the discharge amount of the cooling water pump (P _C ) is changed by the calorie detector (Scal) signal. It is reduced to almost half of the rated value via the cooling water flow control (C _C ).

However, even if such an operation is performed, the high temperature generator (1)
Since there is residual heat in the low temperature generators (2) and the amount of refrigerant generated in these generators does not immediately decrease, and the concentration of the concentrated absorbing liquid sprinkled in the absorber (5) remains almost unchanged for a while. Actually, the refrigeration output that is too large for the load will continue. Therefore, the temperature of the cold water in the water cooler (23) starts to drop, and the temperature of the refrigerant liquid in the evaporator (4) and its saturated vapor pressure also start to drop. If this is left as it is, the cold water and the refrigerant liquid may freeze, causing overload or cavitation of the pumps (P _W ) and (P _R ) and causing them to fail. In such a case, in this device, when the vapor pressure in the evaporator (4) and the absorber (5) or the refrigerant liquid temperature of the refrigerant liquid reservoir (31) drops to a set value, a temperature detector (S _TR ) or pressure detector (S _PE) cold water flow quantity regulator which receives a signal (R _W) is cold water pump in cold water flow controller (C _W) (P _W)
A correction command signal is issued to increase the discharge amount of
Since the amount of cold water supplied to (4) is increased, the freezing of the refrigerant liquid and the freezing of cold water are prevented in advance. Then, the temperature of the refrigerant liquid, the correction command signal when the saturated vapor pressure also rises than the set value coolant flow rate controller regulator for (C _W) (R _W) is released.

The temperature detector (S _TR ) may be provided in the refrigerant liquid sprayer or the pipe (11), and the pressure detector (S _PE ) may be provided in the vapor phase part of the absorber (5). Further, although not shown, pipes (11) and (12) are used instead of the temperature detector (S _TR ) and the pressure detector (S _PE ).
It is also possible to use a detector that senses the flow rate of the refrigerant liquid and the liquid level of the refrigerant liquid reservoir (31).

FIG. 2 is a schematic configuration explanatory view showing another embodiment of this type of apparatus according to the present invention, and in this figure, an example in which the number of chilled water pumps and cooling water pumps is controlled is shown. Incidentally, in FIG. 2, the same components as those shown in FIG. 1 are designated by the same reference numerals,
(S _TW1 ), (S _TW2 ) are temperature detectors, and these emit signals to the controllers (C _W ) and (C _C ) instead of the calorie detector (Scal) shown in FIG. . In this embodiment, the chilled water pump (P _W ) stopped via the chilled water flow controller (C _W ) by the signal of the temperature detectors (S _TW1 ) and (S _TW2 ) is the temperature detector (S _TR ) or We are again operated via the cold-water flow regulator (R _W) and cold water flow controller (C _W) by the signal of the pressure detector (S _PE). Then, the evaporator (4) in the temperature and the regulator (R _W) of the correction command signal is canceled pump of the the saturation vapor pressure is restored to within the normal range coolant flow rate controller (C _W) of the refrigerant fluid (P _W ) is stopped again. Second
In the figure, two chilled water pumps (P _W ) are provided for convenience of explanation.
The cold water pump (P _C ) is shown in the figure, but it goes without saying that a large number of these may be installed.

In the embodiment shown in FIG. 1 and FIG. 2, steam in the high temperature generator (1) and the condenser (3) is temporarily reduced by halving the flow rate of the cooling water supplied to the absorption refrigerator. As the pressure and temperature rise, the liquid level in the high temperature generator (1) falls.
When these reach the set values, the temperature detector (S _TC ), pressure detector (S _PC ), (S _PG ), liquid level detector (S
Cooling water flow rate regulator by either of the signals _L) (R _C),
The discharge amount of the cooling water pump (P _C ) or the number of operating pumps is increased and corrected via the cooling water flow controller (C _C ) to prevent excessive liquid level drop and pressure rise of the high temperature generator (1). . Further, in these embodiments, the case where the cold water flow rate control device of the present invention is applied to the double-effect absorption refrigerator is explained, but it is needless to say that this can be applied to the single-effect absorption refrigerator.

(G) Effect of the Invention As described above, according to the device of the present invention, when the temperature of the refrigerant liquid in the evaporator or the saturated vapor pressure starts to drop with the rapid decrease in the amount of cold water supplied to the absorption refrigerator. When they reach the set values before they drop excessively, the cold water temperature in the water cooler is adjusted by increasing the supply amount of cold water and the temperature of the refrigerant liquid sprinkled in the water cooler of the evaporator and its saturation. The vapor pressure can be increased to prevent freezing of cold water and the refrigerant, the safety device can be prevented from working, and the operation of the absorption refrigerator can be stabilized and continued.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an embodiment of this type of device according to the present invention, and FIG. 2 is a schematic configuration explanatory view showing another embodiment of this type of device according to the present invention. . (1) …… High temperature generator, (2) …… Low temperature generator, (3) …… Condenser, (4) …… Evaporator, (5) …… Absorber, (11), (12)… …
Pipe, (23) …… Chiller, (25), (26) …… Chilled water flow path, (31)…
… Refrigerant liquid reservoir, (P _W ) …… Cold water pump, (P _R ) …… Refrigerant liquid pump, (P _A ) …… Absorbing liquid pump, (C _W ) ……
Cold water flow controller, (R _W ) …… Cold water flow controller,
(S _TR ) …… Temperature detector, (S _PE ) …… Pressure detector.

Claims (3)

[Claims] 1. A generator, a condenser, an evaporator, an absorber, and other devices are connected by piping to form a refrigerant flow path and an absorption liquid flow path, and a cold water flow path is connected to the evaporator. In a device that adjusts the flow rate of cold water by controlling the discharge rate of the cold water pump or the number of operating units, the detector that senses the physical quantity that changes in relation to the change in the flow rate of cold water that flows through the cold water flow path, and this detection If the physical quantity sensed by the detector reaches a set value when the flow rate of the cold water supplied to the absorption chiller is reduced by inputting the signal from the cooling device, the signal is output to the chilled water pump based on the signal. And an adjusting mechanism for increasing and correcting the cold water flow rate. 2. The chilled water flow rate control device for an absorption chiller according to claim 1, wherein the physical quantity is a temperature of the refrigerant liquid in the evaporator. 3. The chilled water flow rate control device for an absorption chiller according to claim 1, wherein the physical quantity is vapor pressure in the evaporator.