JPH049981B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dual-effect absorption refrigerator having a high temperature regenerator and a low temperature regenerator. and a pressure seal between both regenerators. This is used in the field of reducing the number of attached devices and improving the reliability of the above-mentioned functions.

[Conventional technology]

In a dual-effect absorption refrigerator, which is equipped with a high-temperature regenerator and a low-temperature regenerator as regenerators for extracting refrigerant vapor from the dilute absorption liquid, absorption liquid level control in the high-temperature regenerator and absorption liquid level control in the low-temperature regenerator are performed. It is required to maintain the differential pressure between both regenerators when deriving the regenerator.

Its function will be explained below with respect to the dual effect absorption refrigerator shown in FIG.

The dilute absorption liquid 6 of the absorber 5 is introduced into the high-temperature regenerator 4 by the absorption liquid pump 1 via the low-temperature heat exchanger 2 and the high-temperature heat exchanger 3, and is converted into refrigerant vapor by the heater 7 in the high-temperature regenerator 4. It generates and becomes a concentrated absorption liquid. The concentrated absorbent liquid overflowing the weir 8 that maintains the level of the absorbent liquid in the high temperature regenerator 4 flows through an overflow pipe 9,
After passing through high temperature heat exchanger 3, lever type float valve 1
0 to the valve section 11.

On the other hand, since the float valve 10 is communicated with the high-temperature regenerator 4 via the vent pipe 12, the pressure of the high-temperature regenerator 4 is applied to the absorbed liquid level in the float valve 10, which is introduced by branching from the overflow pipe 9. This keeps the liquid level balanced. As the introduction by the absorption liquid pump 1 continues and the amount of absorption liquid overflowing over the weir 8 increases, the liquid level of the float valve 10 rises, the valve 13 opens, and the absorption liquid is introduced into the low temperature regenerator 14. .

In this way, the float valve 10 sends the excess absorption liquid from the high temperature regenerator 4 to the low temperature regenerator 14, but even when there is little or no overflow from the weir 8,
The differential pressure between both regenerators can be maintained by the retained absorption liquid. As a result, the refrigerant vapor generated in the high temperature regenerator 4 is prevented from directly leaking into the low temperature regenerator 14. To avoid the hammering sound in the high-temperature heat exchanger 3 and the erosion phenomenon in the heat exchanger tubes, which would occur if the leakage occurs, and to prevent holes from forming in the heat exchanger tubes and an extreme deterioration in the performance of the refrigerator. It is becoming possible to do this.

On the other hand, if the amount of absorption liquid in the high-temperature regenerator 4 decreases, the high-temperature regenerator 4 will burn out, so the absorption liquid pump 1 is constantly operated so that the absorption liquid stays in the high-temperature regenerator 4.
A dilute absorption liquid is introduced. In order to prevent the absorption liquid level from becoming too high when too much is introduced, a liquid level detector 16 consisting of two electrode rods 15 of different lengths is installed. This means that if the amount of diluted absorbent introduced by the absorbent pump 1 increases excessively beyond the weir 8 during start-up or dilution operation when the differential pressure between the two regenerators is low, the current is turned on using the absorbent as a conductive medium. Electrode rod 15
This allows the absorption liquid pump 1 to be stopped.

That is, the balance between the amount of absorption liquid in the absorber 5 and the high-temperature regenerator 4 is maintained, a decrease in the refrigerant absorption capacity in the absorber 5 and cavitation in the absorption liquid pump 1 are prevented, and refrigerant generation in the high-temperature regenerator is prevented. This will prevent a decrease in capacity and the leakage of absorbent liquid into the steam pipe heading toward the low-temperature regenerator.

[Problem to be solved by the invention]

In such a dual-effect absorption refrigerator, the above-mentioned float valve is of a lever type, and the valve part is structured to open and close by the operation opposite to the vertical movement of the float, and is structurally Due to the complexity of the system, it is easy to cause failures, and there is a problem in that the above-mentioned differential pressure sealing function cannot be achieved.

On the other hand, as shown in FIG. 2, the electrodes of the liquid level detector are airtightly attached to an electrode box 18 that is integrated with the high-temperature regenerator via a gasket 17, but if this deteriorates over time, Outside air enters the high-temperature regenerator, causing deterioration in the performance of the refrigerator and corrosion of various parts.
There is a problem that may cause a malfunction. In addition, if the liquid level detector malfunctions, the above-mentioned phenomena such as cavitation in the absorption liquid pump may occur, and improvements in this situation are strongly desired.

By the way, JP-A-58-55656 discloses a device in which a float valve is provided in an overflow pipe leading from a high temperature regenerator to a low temperature regenerator. The float valve is designed to prevent an abnormal rise in the liquid level of the high temperature regenerator and to prevent leakage of refrigerant vapor from the high temperature regenerator to the low temperature regenerator. However, under normal conditions,
The concentrated absorption liquid in the high-temperature regenerator is introduced into the low-temperature regenerator through a high-temperature heat exchanger path that does not have a float valve, and the float valve does not have the function of circulating the concentrated absorption liquid in the high-temperature regenerator.

Therefore, when there is little or no absorption liquid over the weir of the high-temperature regenerator, it may not be possible to maintain the differential pressure between the high-temperature regenerator and the low-temperature regenerator. In this case, the refrigerant vapor generated in the high-temperature regenerator may escape directly to the low-temperature regenerator, causing a hammering sound in the high-temperature heat exchanger or erosion in its heat transfer tubes. This has the disadvantage of causing a decline in the performance of the refrigerator.

On the other hand, Japanese Utility Model Application Publication No. 52-130257 describes an absorption refrigerator in which a float valve is interposed between concentrated solution tubes that supply absorption liquid from a high temperature regenerator to a low temperature regenerator. The float chamber that operates the float valve includes a liquid side balance pipe branched from the concentrated solution pipe,
It is connected to the gas-side balance pipe connected to the gas phase section of the high-temperature regenerator.

Therefore, the float chamber is not adapted to retain absorption liquid from the high temperature regenerator for supply to the low temperature regenerator. The air side balance tube is
It functions simply as a pressure equalizing pipe, and if the liquid level in the high temperature regenerator rises abnormally, the absorbed liquid cannot be introduced into the low temperature regenerator, and the absorbed liquid is transferred to a high temperature heat exchanger with high flow resistance. It will be passed through a container and introduced into a low-temperature regenerator. Therefore, it is not easy to quickly draw out a large amount of absorption liquid from the high-temperature regenerator, which may impede the generation of refrigerant vapor in the high-temperature regenerator or cause abnormalities such as absorption liquid being sent to the steam pipe. There are drawbacks to situations.

The present invention was made to solve the above-mentioned problem, and its purpose is to pass the absorbed liquid through a high-temperature heat exchanger with large flow resistance when the liquid level in the high-temperature generator rises abnormally. The pressure difference between the high-temperature regenerator and the low-temperature regenerator can be maintained even when there is little or no absorbed liquid over the weir of the high-temperature regenerator; To prevent the refrigerant vapor generated in the heat exchanger from directly escaping to the low-temperature regenerator, thereby preventing hammer noise and heat transfer tube erosion in the high-temperature heat exchanger, and suppressing deterioration in chiller performance. In addition, it is possible to avoid complicating the piping configuration such as installing a new pipe by connecting it to another pipe to prevent refrigerant vapor from escaping, and it is possible to avoid complicating the piping configuration by connecting it to another pipe to prevent refrigerant vapor from escaping. It is an object of the present invention to provide a dual-effect absorption refrigerating machine that enables a reduction in the number of component devices and a reduction in failure frequency, and achieves operational accuracy and improves operating performance.

[Means to solve the problem]

The present invention is designed to prevent the absorption liquid level in the high-temperature regenerator from becoming excessively high, and the concentrated absorption liquid overflowing the weir provided in the high-temperature regenerator exchanges heat with the dilute absorption liquid flowing from the absorber to the high-temperature regenerator. After that, it is applied to a dual-effect absorption refrigerator which is to be introduced into a low-temperature regenerator.

Its characteristics are as shown in Figure 3.
The high-temperature heat exchanger 3 is connected to the outlet pipe 25 through which the concentrated absorption liquid of the high-temperature regenerator 4 is sent out toward the low-temperature regenerator 14.
will be established. Downstream of the high temperature heat exchanger 3,
A direct acting float valve 27 is disposed in the outlet pipe line 25 at a position lower than the weir 8. The direct-acting float valve 27 has a spout 26 that opens at a position higher than the weir 8 of the high-temperature regenerator 4.

〔Effect of the invention〕

According to the present invention, it is possible to maintain the differential pressure between the high-temperature regenerator and the low-temperature regenerator, and to prevent the liquid level from rising too high in the high-temperature regenerator, thereby inhibiting the generation of refrigerant vapor in the high-temperature regenerator. It is possible to avoid an abnormal situation in which the absorption liquid in the high temperature regenerator is sent to the steam pipe connecting the high temperature regenerator and the low temperature regenerator. It is also possible to reduce the frequency of starting and stopping of the absorption liquid pump, reduce its failures, maintain accurate operation at all times, and improve refrigeration performance. Of course, it is possible to speed up the circulation of the absorption liquid at the time of starting and stopping, and also to distribute the desired amount, thereby shortening the time required for starting and stopping.

In addition, cavitation of the absorption liquid pump, leakage of refrigerant vapor, and corrosion caused by intrusion of outside air can be avoided without requiring the preparation of new equipment or piping.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to drawings of embodiments thereof.

FIG. 3 is a system diagram of the dual-effect absorption refrigerator 20 of the present invention, and 21 in the figure is a vacuum tank containing an absorber 5, a low-temperature regenerator 14, a condenser 22, and an evaporator 23. , an absorption liquid pump 1 having a heater 7
A high-temperature regenerator 4 for extracting high-temperature refrigerant vapor from the diluted absorption liquid sent out is attached to the outside of the vacuum tank 21.

Then, the concentrated absorption liquid from the high-temperature regenerator 4 is sent to the outlet pipe 25 toward the low-temperature regenerator 14.
A high temperature heat exchanger 3 is provided. On the other hand, inside the high-temperature regenerator 4, a weir 8 is provided to keep the liquid level of the introduced absorption liquid constant, and an overflow pipe 24 is installed to lead out excess absorption liquid beyond this weir to the low-temperature regenerator 14. has been done. During steady operation, the absorption liquid flowing through the overflow pipe 24 is concentrated by the heater 7 of the high-temperature regenerator 4 and has a high temperature. When it passes through the high-temperature heat exchanger 3, it exchanges heat with the dilute absorption liquid 6, which is directed from the absorber 5 to the high-temperature regenerator 4, and is then introduced into the low-temperature regenerator 14.

A direct-acting float valve 27 is disposed in the outlet pipe line 25 downstream of the high-temperature heat exchanger 3 at a position lower than the weir 8 of the high-temperature regenerator 4 . The direct-acting float valve 27 has a spout 26 that opens at a position higher than the weir 8 of the high-temperature regenerator 4.

The direct-acting float valve 27 has a vertically elongated shape, and stores the low-concentration absorption liquid that has absorbed the high-temperature refrigerant vapor in the high-temperature regenerator 4 introduced from the intake port 26 upward, and stores it in the valve part 28. This makes it possible to avoid mixing with the low-temperature absorption liquid from the high-temperature heat exchanger 3 that has been introduced, and to avoid absorption of the refrigerant.

The spout 26 has a function of drawing out the absorption liquid and sending it to the low-temperature regenerator 14 when the amount of absorption liquid in the high-temperature regenerator 4 increases abnormally. It has a function of maintaining the differential pressure between the high temperature regenerator 4 and the low temperature regenerator 14 by the retained absorption liquid.

Incidentally, 29 is a steam pipe that sends the refrigerant vapor generated in the high-temperature regenerator 4 to the low-temperature regenerator 14, and 2 is a steam pipe that sends the dilute absorption liquid introduced from the absorber 5 to the high-temperature regenerator 4 to the high-temperature heat exchanger 3. Before heating, low temperature regenerator 1
This is a low-temperature heat exchanger that is preheated by the absorption liquid of No. 4.

In the dual-effect absorption refrigerator having such a configuration, the liquid level in the high-temperature regenerator 4 is controlled and the leakage of refrigerant vapor to the low-temperature regenerator 14 is prevented as follows.

First, in steady operation, the diluted absorption liquid 6 of the absorber 5 is pressurized by the absorption liquid pump 1, and the diluted absorption liquid 6 is transferred to the low-temperature heat exchanger 2 and the high-temperature heat exchanger 3.
is heated when it passes through. When introduced into the high-temperature regenerator 4, the dilute absorption liquid 6 generates refrigerant vapor by the heater 7, and becomes a concentrated absorption liquid. In addition,
The heater 7 may be of a direct firing type using heavy oil or the like or a steam heating type, but is always in a heating state while the refrigerator is operating.

A part of the absorption liquid introduced into the high-temperature regenerator 4 becomes refrigerant vapor, and is transferred to the low-temperature regenerator 14 via the steam pipe 29.
The concentrated absorption liquid is stored at a constant level by the weir 8. By the absorption liquid pump 1,
When the dilute absorbent liquid 6 is introduced one after another into the high temperature regenerator 4, the concentrated absorbent liquid crosses the weir 8 and enters the overflow pipe 24.
After passing through the high temperature heat exchanger 3, it is introduced into the valve section 28 of the direct acting float valve 27.

Absorbing liquid has already accumulated in this direct-acting float valve 27, and its liquid level is balanced with the vapor pressure of the refrigerant in the high-temperature regenerator 4 acting through the spout 26. When the amount of concentrated absorption liquid that exceeds the weir 8 increases, the amount of liquid in the direct acting float valve 27 increases, and the internal float 27a rises. Along with this, the valve body 28
a separates from the valve seat 28b, and the amount of liquid that has exceeded the weir 8 is introduced into the low temperature regenerator 14.

Regardless of the presence or absence of absorbed liquid over the weir 8, the high temperature regenerator 4 is affected by the liquid level located below the intake port 26 of the direct acting float valve 27 and the liquid level of the retained liquid in the overflow pipe 24. The low-temperature regenerator 14 and the high-temperature regenerator 4 are maintained in a disconnected state, and refrigerant vapor generated in the high-temperature regenerator 4 is prevented from leaking into the low-temperature regenerator 14.

On the other hand, when the refrigerator is started or during dilution operation after stopping, the differential pressure between the high temperature regenerator 4 and the low temperature regenerator 14 is low, and the absorption liquid pump 1 is still operating. , the dilute absorption liquid is introduced into the high temperature regenerator 4, which is not at a predetermined pressure state, to a height that significantly exceeds the weir 8. When this happens, the absorption liquid is discharged from the spout 26 of the direct acting float valve 27, and the liquid level of the direct acting float valve 27 rises significantly.

Therefore, the float 27a floats up, and the valve body 28a separates from the valve seat 28b. The valve part 28 opens, and both the absorbent liquid from the drinking spout 26 and the absorbent liquid from the overflow pipe 24 flow into the low temperature regenerator 14.
is derived. In particular, a large amount of absorption liquid is discharged from the spout 26 that bypasses the high-temperature heat exchanger 3, which has a large flow path resistance, and this may impede the generation of refrigerant vapor in the high-temperature regenerator 4, or even worse, the high-temperature regenerator 4 This can be prevented by sending the absorbed liquid in the tank through the steam pipe 29 to the regenerator pipe of the low temperature regenerator 14.

At startup, a pressure difference between the high-temperature regenerator 4 and the low-temperature regenerator 14 gradually arises, so that the operation similar to the above-mentioned steady-state operation is performed. During dilution operation,
The concentration of all the absorbent liquids is quickly equalized, and the inability to restart operations due to absorbent precipitation is prevented.

In such an operation, the direct acting float valve 2
7 functions to introduce the absorption liquid into the low-temperature regenerator 14 while maintaining the differential pressure between the high-temperature regenerator 4 and the low-temperature regenerator 14, and when the liquid level in the high-temperature regenerator 4 becomes too high, the absorbent without stopping the liquid pump 1.
The absorption liquid is circulated through a path with low flow resistance,
The amount of absorption liquid at each location can be maintained appropriately. Further, the direct-acting type float valve 27 is a direct-acting type having a simple structure, and can reduce the occurrence of failures such as impairing the opening and closing of the valve portion.

As explained in detail above, a direct-acting float valve with a spout that opens higher than the weir of the high-temperature regenerator is used to regenerate the absorbed liquid from the high-temperature regenerator at a low temperature via a high-temperature heat exchanger. Since it is interposed in the outlet pipe that sends out to the refrigerant, it maintains the differential pressure between the high-temperature regenerator and the low-temperature regenerator and prevents the liquid level from rising too high in the high-temperature regenerator, thereby inhibiting the generation of refrigerant vapor in the high-temperature regenerator. At the same time, it is possible to achieve the effect of avoiding abnormal situations that would occur if the absorption liquid were sent to the steam pipe.

Therefore, unlike in the past, there is no need to install component equipment according to each function, and malfunctions of these components can cause capitation of the absorption liquid pump, leakage of refrigerant vapor, and even damage to outside air. Corrosion caused by intrusion is eliminated.
In addition, by reducing the frequency of starting and stopping of the absorption liquid pump, accurate operation with fewer failures is realized, and refrigeration performance is improved. The circulation of the absorption liquid during startup and shutdown can also be distributed quickly and in the desired amount, reducing the time required for them.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a conventional dual-effect absorption refrigerator, Fig. 2 is a sectional view of an electrode installed in a liquid level detector, and Fig. 3 is a system diagram of a dual-effect absorption refrigerator according to the present invention. It is. 3...High temperature heat exchanger, 4...High temperature regenerator, 5...
...Absorber, 6... Dilute absorption liquid, 8... Weir, 14...
Low temperature regenerator, 20...Double effect absorption refrigerator, 25
... Outlet pipe line, 26 ... Drinking spout, 27 ... Direct acting float valve.

Claims (1)

[Claims] 1. The absorption liquid level in the high-temperature regenerator is prevented from becoming excessively high;
A double-effect absorption system in which the concentrated absorption liquid overflowing the weir installed in the high-temperature regenerator exchanges heat with the diluted absorption liquid flowing from the absorber to the high-temperature regenerator, and then is introduced into the low-temperature regenerator. In the refrigerator, a high-temperature heat exchanger is provided in the outlet pipe through which the concentrated absorption liquid of the high-temperature regenerator is sent toward the low-temperature regenerator, and a high-temperature heat exchanger is provided downstream of the high-temperature heat exchanger and in the outlet pipe. A direct acting float valve is disposed at a position lower than the weir of the high temperature regenerator, and the direct acting float valve has a spout that opens at a position higher than the weir of the high temperature regenerator. Absorption refrigerator.