JPS62166271A - Absorption refrigerator - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention provides a method for boiling 1112! Absorption refrigerators and absorption heat pumps (hereinafter referred to as this type of absorption refrigerator) that pump the quenched absorption liquid to a gas-liquid separator using refrigerant bubbles.
In particular, the present invention relates to improvements in this type of absorption refrigerating machine that prevent dry firing of the generator and overflow of absorption liquid from the gas-liquid separator to the condenser.

(B) Conventional technology This type of absorption refrigerator uses a flooded generator with a structure similar to a furnace tube boiler, which consists of a combustion chamber that heats and concentrates the dilute absorption liquid and a number of smoke tubes arranged above the combustion chamber. Compared to a built-in absorption refrigerator, it has the advantage of requiring a small amount of expensive absorption liquid and reducing fuel consumption accordingly.
As seen in Japanese Utility Model Publication No. 6702, Japanese Utility Model Publication No. 46-7955, Japanese Utility Model Publication No. 56-218, and Japanese Utility Model Publication No. 58-52466, it has been widely used mainly in small-sized absorption refrigerators.

(c) Problems to be solved by the invention Although this type of absorption refrigerator has the above-mentioned advantages, the absorption liquid in the gas-liquid separator enters the condenser side at the time of startup. This has the problem that it is easy to cause over-keying. For this reason, in this type of absorption refrigerator, a reversible pump is used as the pump for feeding the diluted absorption liquid to the generator, as seen in Japanese Patent Application Laid-Open No. 57-169569, and a reversible pump is used to supply the diluted absorption liquid to the generator. A method has been proposed in which the pump is rotated in reverse until the liquid reaches a predetermined temperature, thereby reducing the amount of dilute absorption liquid fed and preventing carryover. However, although this method is useful at startup when the temperature of the liquid in the generator is close to the outside temperature, it hardly works effectively at partial loads when the temperature of the liquid is close to the predetermined temperature.

In this type of absorption refrigerator, when the heating amount is reduced without stopping the heating of the generator during partial load, the amount of bubbles generated in the generator is larger than the amount of absorbed liquid flowing from the gas-liquid separator to the absorber side. Because the amount of absorbed liquid that flows into the gas-liquid separator tends to increase due to the liquid pumping action, there is a problem that carryover tends to occur. Furthermore, during partial load to reduce the heating amount of the generator, the amount of diluted absorption liquid sent to the generator is also reduced, so in this type of absorption refrigerator, absorption liquid is unevenly distributed in the gas-liquid separator. There is also the problem that the generator tends to run dry.

In view of these problems, it is an object of the present invention to provide an absorption refrigerator of this type that can reliably prevent harmful effects such as carryover and dry firing during partial loads that reduce the heating amount of the generator. .

(d) Means for Solving the Problems The present invention, as a means for solving the above problems, uses a reversible pump as a pump for dilute absorption liquid, and also uses a reversible pump between the gas-liquid separator and the generator. A liquid return line with a check valve or other valve is provided, and when the liquid level sensed by the liquid level detector installed in the gas-liquid separator rises to a set value, the reversible pump is reversed to reduce the amount of dilute absorption liquid sent. This type of absorption refrigerator is configured so that when the detected liquid level rises to the upper limit, the reversible pump is stopped and the valve is opened to return the liquid in the gas-liquid separator to the generator.

(E) Function In this type of absorption refrigerator according to the present invention, if the liquid level in the gas-liquid separator rises above a set value during startup or partial load, the generator and gas-liquid separator If the absorption liquid reaches the upper limit, the absorption liquid in the gas-liquid separator is returned, but if the liquid level drops to a predetermined level, the absorption liquid is returned to the generator and the gas-liquid separator. The liquid level within the gas-liquid separator is adjusted within a predetermined range. This function makes it possible to reliably prevent adverse effects such as carryover and dry firing of the generator, which tend to occur in this type of absorption refrigerator during partial loads.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Embodiment The drawings are schematic structural explanatory diagrams showing one embodiment of this type of absorption refrigerator according to the present invention. In the figure, (1) is a high-temperature generator that heats the dilute absorption liquid using combustion gas such as gas or oil, and (2) is a high-temperature generator heated by the high-temperature generator (1) and a liquid pump (3).
) is a gas-liquid separator that separates refrigerant from the absorption liquid that has risen together with refrigerant vapor bubbles; (4) is a gas-liquid separator (
(5) a low-temperature generator that uses the refrigerant vapor separated in step 2) as a heat source to further heat the intermediate concentration absorption liquid and separate the refrigerant;
The refrigerant flowing from the generators (1) and (4) is transferred to the cooler (6).
(7) is an evaporator that obtains cold water from a heat exchanger (8) by using latent heat when the refrigerant liquid from the condenser (5) is dispersed and vaporized; (9) is a trap installed in the overflow pipe that causes the absorption liquid in the gas-liquid separator (2) to overflow to the low-temperature generator (4); The separated concentrated absorption liquid is sprayed to absorb the gaseous refrigerant in the evaporator (7).
) The absorber can continuously supply cold water by maintaining a low pressure inside the absorber. (11) is the on-off valve (12).
), and by opening this on-off valve during heating, hot water can be taken out from the heat exchanger (8) while guiding the high-temperature refrigerant in the gas-liquid separator (2) to the evaporative absorption shell (13). The bypass pipe (14) is used to connect the absorber (10) during heating and cooling.
) is a reversible absorption liquid pump that returns the dilute absorption liquid from the generator (1) to the generator (1), (15) and (16) are low temperature and high temperature solution heat exchangers, which are connected to the refrigerant line (17). ,(18),
The refrigerant [water] is connected with the absorption liquid pipes (19), (20), (21), the liquid pumping pipe (3), the bypass pipe (11), etc., and is the same as in the conventional absorption refrigerator of this type. and constitutes a circulation path for the absorption liquid [lithium bromide aqueous solution].
(22) is a burner provided in the high temperature generator (1),
(23) is a refrigerant liquid pump.

(24) is a gas-liquid separator (2) and a high temperature generator (1).
), and this pipe is equipped with an on-off valve (■) such as a water valve or an electric valve.

In addition, (LS) is a liquid level detector that detects the liquid level in the gas-liquid separator (2), and this detector has electrodes (PI) that sense the upper limit liquid level, set liquid level, and lower limit liquid level, respectively. >, (P2),
(P,) is built-in. (C) is a controller to which a signal from a liquid level detector (LS) is input. When the liquid level in the gas-liquid separator (2) rises to the set liquid level at the end of the electrode (P2), the controller (C) stops energizing the motor of the absorption liquid pump (14). The magnet (M2), which is switched in the opposite direction and rotates this motor in the opposite direction, is energized, and the electrode <P,)
When the liquid level rises to the upper limit at the end, the power to the motor is cut off, the pump (14) stops, and at the same time the on-off valve (
V) is opened, while the liquid level begins to drop and the electrode (P
I) When the liquid level drops to the lower limit of the end, the controller (C) closes the on-off valve (V-n) again and at the same time the pump <1
The magnet (Ml) that rotates the motor in 4> in the forward direction can be energized. In addition, when the pump rotates in reverse (
14) The discharge amount is 40 to 60% of that during forward rotation.

In addition, (TS) is a sensor that detects the cold/hot water temperature on the outlet side of the heat exchanger (8), and the opening degree of the fuel control valve (V,) is controlled by the signal from this sensor via the regulator (R). As a result, the structure is such that the heating amount of the high temperature generator (1) is adjusted in the same manner as the conventional absorption refrigerator of this type.

Next, an example of the operation of the absorption refrigerating machine (hereinafter referred to as the present machine) configured as described above will be explained.

Now, while the machine is operating, for example, if the number of rooms that require cooling is halved and the cooling load changes from 100% to 50%,
The opening degree of the fuel control valve (V,) can be controlled to 50% by the signal from the sensor (Is) via the regulator (R), and the heating amount of the high temperature generator (1) can be reduced to almost the same amount. As the amount of heating is halved, the vapor pressure in the high temperature generator (1) and the gas-liquid heat separator (2) begins to drop, and the pressure difference between the gas-liquid separator and the low-temperature generator (4) is no longer necessary. Gas-liquid separator (
2) The amount of absorbent flowing out from 2) begins to decrease. On the other hand, although the liquid pumping effect from the high-temperature generator (1) to the gas-liquid heat divider (2) declines, the absorption from the absorber (10) to the high-temperature generator (1) and gas-liquid separator (2) side decreases. Since the amount of liquid sent is almost the same as before the cooling load change, the balance between the amount of liquid in and out of this gas-liquid separator is disrupted and the liquid level begins to rise.Then, the electrode of the liquid level detector (LS) (P2) When the liquid level rises to the lower end, the motor of the absorption liquid pump (14) is switched from forward rotation to reverse rotation, and the amount of absorption liquid sent to the high temperature generator (1) is reduced by approximately half. .

By reducing the amount of absorption liquid sent by almost half, the lack of heat in the high-temperature generator (1) is resolved, and the vapor pressure in this generator and the gas-liquid heat separator (2) begins to rise again, causing the gas-liquid separator to rise. The amount of absorption liquid flowing out from (2) also begins to increase, and the liquid pumping action from the high temperature generator (1) to the gas-liquid separator (2) also becomes active. However, in this type of absorption refrigerator, the amount of absorption liquid flowing into the gas-liquid separator (2) due to liquid pumping and the amount of absorption liquid flowing out from the gas-liquid separator (2) due to pressure increase are not necessarily equal. Since it does not increase in a well-balanced manner, a gas-liquid separator (2
), the absorbing liquid is unevenly distributed in the condenser (5) and tends to often carry over to the condenser (5) side. Furthermore, a gas-liquid separator (
2) When the amount of absorption liquid sent to the high-temperature generator (1) decreases due to the uneven distribution of absorption liquid within the generator, this generator may not be able to store enough liquid, resulting in a situation close to dry firing. .

In such a case, in this machine, the absorption liquid pump (14) stops operating when the liquid level in the gas-liquid separator (2) rises to the electrode (P,) end of the detector (LS). At the same time, the valve (V) is opened and the absorption liquid in the gas-liquid separator (2) is returned to the high temperature generator (1) via the pipe (24). As a result, the uneven distribution of the absorption liquid in the gas-liquid separator (2) is eliminated,
Carry-over of the absorption liquid and dry firing of the high temperature generator (1) are reliably prevented.Instead of using a solenoid valve, electric valve or other shut-off valve, the valve (V) is a check valve (shown with a broken line). ■
c) may also be used. When a check valve (VC) is used, by stopping the pump (14), the pump discharge pressure that acts as the closing force of the check valve (VC) is released, the valve opens, and the gas-liquid separator (2 ) is absorbed into the high temperature generator (
Returned to 1). For this reason, the controller (C) and the check valve (V
, l:), which has the advantage of simplifying the control circuit.

As can be seen from the explanation of the operation example above, an absorption chiller incorporating a flooded generator with a structure similar to that of a fire tube boiler has a problem that is hardly a problem, that is, the heating amount of the generator and the absorption liquid This machine reliably eliminates the problems peculiar to this type of absorption refrigerator, such as carryover of absorbent liquid in the gas-liquid separator (2) and dry firing of the generator (1), which tend to occur during partial loads when the feed rate is reduced. It can be prevented.

In addition, in this machine, when the liquid level of the gas-liquid separator (2) falls to the end of the electrode (P,) of the detector (LS>), the absorption liquid pump (14) is operated again and at the same time the valve (v ) is closed and the liquid level in the gas-liquid separator (2) is maintained between the electrode (P, ) ends and the electrode (P, ) ends.

In addition, in this machine, the controller (
When the pump 14) is operated again by C), the signal from the sensor (I'S) is sent to the controller (C) for cascade control, so that the magnet (L) is activated at partial load.
) may be activated to rotate the pump (14) motor in the reverse direction.

(G) Effects of the Invention As described above, in this type of absorption refrigerator according to the present invention, the gas-liquid separator that tends to occur during partial load when the heating amount of the generator and the amount of absorption liquid sent to the generator are reduced. This brings about the effect of reliably preventing the uneven distribution of the absorption liquid, the accompanying carryover of the absorption liquid to the condenser side, and the dry firing of the generator.

It goes without saying that the present invention can be applied to this type of single-effect absorption refrigerator.

Lifting pipe, (4)...low temperature generator, (5)...condenser, (7)...evaporator, (8>...heat exchanger,
(10>...Absorber, (14)...Absorption liquid pump, (17), (18), (19), (20), (2
1)...Pipe line, (22)...Burner, (2
4)...liquid return pipe line, (C)...controller, (L
S)...liquid level detector, (Ml), (shi)...magnet, (R)...regulator, (I'S)...sensor, (V)...open/close valve, (VC)...Check valve,
(VF)...Fuel control valve.

Claims (1)

[Claims] (1) The absorbed liquid concentrated in the generator and the refrigerant vapor generated rise to a gas-liquid separator via a pipe, and the absorbed liquid separated by this gas-liquid separator is guided to the absorber side, and the separated refrigerant is condensed. In an absorption refrigerator configured to lead to the evaporator side,
A reversible pump, which discharges less liquid during reverse energization than during normal energization, is installed in the pipeline that sends the absorption liquid from the absorber to the generator side, and a reversible pump is installed between the gas-liquid separator and the generator. A liquid return line with check valves and other valves is installed, and the reversible pump can be switched between forward and reverse energization based on signals from a liquid level detector that detects multiple liquid levels in the gas-liquid separator. Alternatively, an absorption refrigerating machine characterized by being equipped with a controller that adjusts the liquid level within a gas-liquid separator to within a predetermined range by starting and stopping a pump and opening and closing a valve.