JPS6262163A - Cooling-water flow controller for absorption refrigerator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a device (hereinafter referred to as
This type of device).

(b) Conventional technology As a conventional technology for this type of device, for example,
As seen in Publication No. 2216, when the load is 50%, one of the two cooling water pumps is stopped, the operation of the refrigerant pump and the heating of the generator are temporarily suspended, and a predetermined increase in the temperature of the chilled water is performed. It is known to maintain low-load operation of an absorption chiller by stopping one of the chilled water pumps and restoring operation of the refrigerant pump and heating of the generator.

→ Problems to be solved by the invention In the conventional device of this kind described above, when the load on the absorption chiller suddenly changes from 100% to 50%, heating of the generator is temporarily interrupted and the chilled water temperature is kept at a predetermined level. Since one of the two cold water pumps is stopped after waiting for the rise, it is possible to reliably prevent cold water from freezing when the load suddenly decreases. However, when the load suddenly decreases, the operation of the refrigerant pump is temporarily stopped, but the operation of the absorption liquid pump continues and the refrigerant is absorbed by the absorber. The refrigerant liquid or the refrigerant liquid in the upper part M of the refrigerant liquid reservoir of the evaporator may freeze. In this case, the first safety device for preventing overload of the refrigerant pump and prevention of cavitation is activated, and even if the cold water rises to a predetermined temperature, the operation of the refrigerant pump and the heating of the generator are not resumed. For this reason,
There was a problem in that the operation of the absorption chiller remained suspended, causing the temperature of the chilled water to rise more than necessary.

In addition, since the heating of the generator is temporarily interrupted, it takes time to restart the operation, which causes the problem that the operation tends to become unstable.

The present invention prevents the problem of freezing of the refrigerant and cold water when rapidly reducing the amount of cold water supplied to the absorption chiller by controlling the number of pumps and controlling the discharge amount, thereby improving the operation of the absorption chiller. The purpose is to provide this type of device that can be stably continued.

(-4) Means for Solving the Problem The present invention provides a method for solving the problem (11. Means for solving this problem). If physical quantities related to the evaporator, such as refrigerant liquid temperature and vapor pressure, are specified in the set values, this type of device is equipped with a regulator that issues an increase correction signal for the chilled water flow rate in response to a signal from a detector that senses these physical quantities. The structure is designed to prepare for the future.

(E) Function According to this type of device of the present invention, when the temperature and vapor pressure of the refrigerant liquid in the evaporator reach the set values before they drop excessively, the flow rate of chilled water in the evaporator is corrected by increasing the refrigerant liquid temperature. Since the absorption refrigerating machine has the effect of raising the temperature and its saturated vapor pressure again, it is possible to prevent the freezing of the refrigerant and, by extension, the freezing of the chilled water.

And traditional absorption with this kind of equipment? '＠Compared to a freezing machine5, its operation can be continued more stably.

(v) Embodiment V FIG. 1 is a schematic structural explanatory diagram showing an embodiment of this type of apparatus according to the present invention. In Figure 1, (1) is a high temperature generator, (2) is a low temperature generator, (3) is a condenser, and (4) is a low temperature generator.
) is the evaporator, (5) is the absorber, (6) and (7) are the low temperature and high temperature solution heat exchangers, respectively, (PIl) is the refrigerant liquid pump, and (PA) is the absorption liquid pump. Pipe through which refrigerant flows (8), (91, Pipe through which refrigerant liquid flows (101)
, pipe where the refrigerant liquid returns (old), az, pipe where the dilute absorption liquid is sent (131, alpha core, pipe where the medium concentration absorption liquid flows, a
6), a pipe (17) through which concentrated absorption liquid flows, and (181) are connected to form a circulation path for refrigerant [water] and absorption liquid [lithium bromide aqueous solution] similar to the conventional dual-effect absorption refrigerator. There is.

C9 is the combustion heating chamber of the high temperature generator (1), ■, ■... are tubes for heating the absorption liquid through which combustion gas flows, c! D is the heater of the low temperature generator (2), (2z is the cooler of the condenser (3), (
231 is the water cooler of the evaporator (4), (2) the absorber (5)
It is a cooler. G.1:! Fit is a cold water pipe connecting the water cooler Ω and a load-side heat exchange unit (not shown), and this pipe is equipped with a cold water pump (P, ) with a variable discharge amount. Also, C2η, (2LI29) is the cooler (24
This is a cooling water flow path in which 1 and 2' are connected in series, and a cooling water pump (Pc) with a variable discharge amount is installed in this flow path. A supply line is provided with a fuel control valve (V,).

(Sc101t) is a calorie detector that senses the cold water temperature and cold water flow rate of each pipe (29, (P, )
The discharge amount of the cooling water pump (PC) is controlled via the cooling water flow rate controller (Cc). In addition, (R4,) is the cooling water flow '! built in the cooling water flow controller (Cc)! This regulator receives the signal from the liquid level detector (SL) installed in the high temperature generator (1) and detects when the liquid level sensed by the liquid level detector (S, , ) is below the set value. Then, a command signal is issued to the controller (Cc) to increase the pump (PC) discharge amount, such as returning the pump (Pc) discharge amount that has been reduced by the cooling water flow value controller (Cc) to the original amount. It has become. Note that the cooling water flow rate regulator (R1) may also be provided with a function to increase the discharge amount according to the rate of descent of the liquid level in the high temperature generator (1). It is convenient to use a liquid level detector that has a number of built-in electrodes of different heights.Also, it is advantageous to use a liquid level detector that has many built-in electrodes of different heights. Signal to cooling water flow regulator (
Rc) may be input.

When any of these detectors is used, when the detected physical quantity becomes higher than a set value, a correction signal is output from the regulator (Rc) to the controller (Cc).

In addition, (R,) is a cold water flow rate regulator built into the cold water flow rate controller (C,,), and this regulator is connected to a temperature sensor (ST, l) installed in the liquid reservoir 6υ of the evaporator (4). )
Alternatively, a pressure detector (S) installed in the gas phase of the evaporator (4)
, , ), and when the sensed physical quantity becomes less than the set value, the pump (P, ) is sent to the controller (C,).
,) A command signal for increasing the discharge amount is issued.

In addition, (S?, ) is a cold water temperature detector installed in the pipe ω, and the signal from this detector adjusts the opening degree of the fuel i1i control valve (V2) via the temperature regulator (Tc). It has become.

Next, the chilled water flow rate adjustment device (hereinafter referred to as
An example of the operation of this apparatus (referred to as a) will be explained together with the operation of an absorption refrigerator.

Now, while the absorption chiller is operating, for example, when the load decreases from 100% to 50%, the refrigeration output of the absorption chiller becomes excessive compared to the load, so the first step is to balance the refrigeration output with the load. will be started. That is, the fuel control valve (V,) operates the temperature regulator (Tc) in response to the signal from the cold water temperature detector (S?W).
The discharge amount of the cold water pump (Pw) is reduced to approximately half of the rated value via the cold water flow controller (C,) by the signal of the calorie detector <5CQt). Cooling water pump (P
The discharge amount of C) is reduced to approximately half of the rated value by the signal of the calorie detector (SIEt) via the cooling water flow controller (Cc).

However, even if such an operation is performed, the high temperature generator
1 and the low temperature generator (2), the amount of refrigerant generated by these generators does not immediately decrease, and the concentration of the concentrated absorption liquid sprayed into the absorber (5) remains constant for a while. Since this does not change, the refrigeration output will actually continue to exceed the load by a factor of X. Therefore, the temperature of the chilled water in the water cooler t231 begins to drop, and the temperature of the refrigerant liquid in the evaporator (4) and its saturated vapor pressure also begin to drop. and,
If this is left as is, the cold water and refrigerant liquid may freeze, causing overload or cavitation of the pumps (Pw) and (P8), which may cause them to malfunction.

In this case, in this device, the vapor pressure in the evaporator (4) and absorber (5) or the refrigerant liquid reservoir 3])
When the temperature of the refrigerant drops to the set value, the temperature detector (S
The chilled water flow regulator (R,) receives the signal from the pressure detector (S, l) or the chilled water flow controller (TR).
A correction command signal is issued to increase the discharge amount of the cold water pump (P,) to Cw), and the amount of cold water supplied to the evaporator (4) is increased, thereby preventing freezing of the refrigerant liquid and freezing of the cold water. Prevented. Then, when the temperature and saturated vapor pressure of the refrigerant liquid rise above the set values, the correction command signal of the regulator (R,) to the chilled water flow rate controller (CW) is released.

Note that the temperature detector (S, , ) is connected to a refrigerant liquid sprayer or pipe (
11), and the pressure detector (S, , ) may be provided in the gas phase section of the absorber (5). Although not shown, a temperature detector (S□) and a pressure detector (S,
It is also possible to use a detector that senses the refrigerant liquid flow rate of the pipe port], (lz, the liquid level of the refrigerant liquid reservoir C11l, etc.) instead of the pipe port.

FIG. 2 is a schematic structural explanatory diagram showing another embodiment of this type of equipment according to the present invention, and this figure shows an example in which the number of cold water pumps and cooling water pumps is controlled. In addition, in FIG. 2, components similar to those shown in FIG. 1 are given the same symbols.
(STw, ON (STw2) are temperature detectors, which issue signals to the controllers (C,), (Cc) in place of the calorie detector (Salt) shown in Figure 1. In the example, a temperature sensor (S?,,),
(S?W2) signal causes chilled water flow rate controller (C
- The chilled water pump (P,) stopped via the temperature sensor (S?R) or pressure detector (S□) causes the chilled water flow regulator (R,) and chilled water flow controller (C,) It will be operated again via . When the temperature of the refrigerant liquid in the evaporator (4) and its saturated vapor pressure return to normal ranges, the chilled water flow controller (
The correction command signal of the regulator (R,) to the regulator (R,) is canceled and the pump (P-) is stopped again. In Fig. 2, for convenience of explanation, two cold water pumps (P, ) and a cooling water pump (Pc) are shown in the figure, but it goes without saying that a large number of these may be installed.

In addition, in the embodiment shown in Fig. 1 and Fig. 2, the flow rate of cooling water supplied to the absorption refrigerator is halved, so that the steam in the high temperature generator (1) and the condenser (3) is temporarily reduced. As the pressure and temperature rise, the liquid level inside the high temperature generator fII falls. When these reach the set values, the temperature sensor (S, c) and pressure sensor (S, , ) are activated.

Discharge of the cooling water pump (P, , ) via the cooling water flow regulator () 1c) and the cooling water flow controller (Cc) according to the signal from either the liquid level detector (SL) or the liquid level detector (S, , ). The quantity or number of units in operation is corrected to increase, and the high temperature generator fi+
Excessive liquid level drop and pressure rise are prevented. Furthermore, in these embodiments, a case has been described in which the chilled water flow rate adjusting device of the present invention is applied to a dual-effect absorption refrigerator, but it goes without saying that this can also be applied to a - type dynamic absorption refrigerator.

(G) Effects of the Invention As described above, according to the apparatus of the present invention, when the temperature and saturated vapor pressure of the refrigerant liquid in the evaporator begin to drop due to a sudden decrease in the amount of cold water supplied to the absorption chiller, When these reach the set values before they drop excessively, adjust the supply amount of chilled water to increase the temperature of the chilled water in the water cooler, as well as the temperature of the refrigerant liquid sprayed in the evaporator water cooler and its saturation. Increase vapor pressure.

Freezing of chilled water and refrigerant can be prevented, and the operation of the absorption refrigerator can be stabilized and continued by preventing the safety device k from working.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural explanatory diagram showing one embodiment of this type of device according to the present invention, and FIG. 2 is a schematic structural explanatory diagram showing another embodiment of this type of device according to the present invention. . (1)...High temperature generator, (2j...Low temperature generator,
(3)... Condenser, (41... Evaporator, (5)
...Absorber, (111,021...Pipe, C...Water cooler, (, B5), Sea fat...Cold water flow path, (
31)...Refrigerant liquid reservoir, (P, )...Cold water pump, (PR)...Refrigerant liquid pump, (P
,)...Absorbent pump. (Cw)...Cold water flow controller, (R,
)...Cold water flow rate regulator, (S,)...Temperature detector, (S. tsu)...Pressure detector.

Claims (3)

[Claims] (1) A device that adjusts the flow rate of chilled water by controlling the discharge amount of chilled water pumps installed in the chilled water flow path of an absorption chiller or by controlling the number of pumps in operation, which is equipped with a detector that senses a physical quantity related to the evaporator, and and an adjustment mechanism that increases and corrects the chilled water flow rate based on a signal from the detector when the physical quantity sensed by the detector reaches a set value when the flow rate of chilled water supplied to the absorption chiller is reduced by the device. A chilled water flow rate adjustment device for an absorption chiller featuring: (2) The chilled water flow rate adjustment device for an absorption refrigerator according to claim 1, wherein the physical quantity is a refrigerant liquid temperature in an evaporator. (3) The chilled water flow rate adjustment device for an absorption refrigerator according to claim 1, wherein the physical quantity is vapor pressure within the evaporator.