JPH0377427B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a dual-effect absorption refrigeration system.

``Prior art'' In conventional dual-effect absorption refrigerators, the high temperature generator is equipped with a solution level detection mechanism, and a signal from the detection mechanism is used to start and stop the solution pump that sends the diluted solution to the high temperature generator. The generator's liquid level was controlled.

FIG. 1 shows an example of a conventional device.

In Figure 1, 1 is an absorber, 2 is an evaporator, and 3
is a high temperature generator, 4 is a low temperature generator, 5 is a condenser, 6
is a high temperature heat exchanger, 7 is a low temperature heat exchanger, 8 is a solution pump, 9 is a refrigerant pump, 10 is a solution flow rate control valve,
11 is a liquid level detector of the high temperature generator 3, 12 is a control device, and 13 is a throttle mechanism, and these devices are connected by a solution path and a refrigerant path.

If the solution level in the high temperature generator 3 rises abnormally due to the solution flow rate control valve 10 not being able to throttle the inflow of the dilute solution during operation, the liquid level detector 1 of the high temperature generator 3
1 causes the control device 12 to control the solution pump 8.
, the supply of the dilute solution to the high temperature generator 3 is stopped, the rise in the liquid level is suppressed, and after the liquid level returns to normal, the solution pump 8 is operated to supply the dilute solution to the high temperature generator 3.
supply to.

However, in this case, if the solution pump 8 is stopped, the refrigeration performance will deteriorate, and if the solution pump 8 is repeatedly started and stopped, it will have an adverse effect on the solution pump 8, or if the differential between starting and stopping is large,
The total amount of solution fed decreases, leading to overconcentration in the high temperature generator 3 and a crystallization accident. Furthermore, if the cause of the abnormal rise in the liquid level of the high temperature generator 3 is crystals generated in the solution path in the high temperature heat exchanger 6, stopping the solution pump 8 will cause a delay in the crystallization operation.
There were drawbacks such as:

In addition, as an example of this improvement, a solution level detection mechanism is provided in the high temperature generator, and a signal from the detection mechanism opens and closes a bypass valve in a solution bypass pipe provided between the solution outlet of the high temperature generator and the low temperature generator. A method has also been proposed.

An example of this is shown in FIG. 14 is a bypass valve.

In Fig. 2, if during operation, the solution flow control valve 1
At 0, the inflow of dilute solution could not be fully throttled and the high temperature generator 3
When the level of the solution inside rises abnormally, the control device 12 opens the bypass valve 14 in response to a signal from the high temperature generator liquid level detector 11 to release the solution to the low temperature generator 4, suppressing the rise in the liquid level, and reducing the level of the liquid. After returning to normal, the bypass valve 14 is closed.

In this system, the heat of the bypassed solution results in energy loss, so the bypass valve 14 is required to have high shutoff performance when closed and to be highly vacuum-tight. Furthermore, since the gate valve is located in a high temperature section, an expensive valve with high temperature resistance and corrosion resistance is required.
Moreover, it has a complicated structure including a liquid level detector 11, a control mechanism 12, and a bypass valve 14, and has the disadvantage of being expensive.

In addition, as an example of this improvement, a liquid level detection box is installed in the high temperature generator, and the float valve in the overflow pipe installed between the high temperature generator and the low pressure side solution path is opened and closed depending on the liquid level in the liquid level detection box. A method has also been proposed.

An example is shown in FIG. 15 is a float valve;
16 is a liquid level detection box, and 17 is an overflow pipe.

During operation, if the solution flow rate cannot be fully adjusted by the solution flow rate control valve 10 and the solution level in the high temperature generator 3 rises abnormally, the float valve 15 will perform an opening operation depending on the liquid level in the liquid level detection box 16. The solution is released to the low-pressure side solution path through the overflow pipe 17 to suppress the rise in the liquid level, and when the liquid level returns to normal, the float valve 15 performs a closing operation.

The internal pressure of the high temperature generator during normal rated operation is 700mmHg.
The internal pressure of the low temperature generator is approximately 55 mmHg. That is, the pressure difference is 645 mmHg, which is a large pressure difference of about 5 m in terms of a solution column when LiBr liquid is used as the absorption liquid. For this purpose, the float valve 15 requires a high-precision valve seat with high sealing performance when fully closed, and a float valve with large operating torque to overcome the pressure difference and open the valve, which increases the size and cost of the device. There was a drawback.

``Object of the Invention'' The present invention aims to provide a dual-effect absorption refrigeration system that does not require high-performance valves, has a simple structure, and is highly reliable, except for the above-mentioned drawbacks of the conventional ones. It is.

"Structure of the Invention" The present invention provides a dual-effect absorption refrigeration system having an evaporator, an absorber, a high-temperature and low-temperature generator, a condenser, a high-temperature and low-temperature heat exchanger, and a solution path and a refrigerant path connecting these devices. A high-pressure holding mechanism for maintaining the internal pressure of the high-temperature generator at a high pressure is provided in a solution path from the high-temperature generator to the low-temperature generator, or in a solution path from the high-temperature generator to the absorber. , a solution overflow pipe is provided in the high temperature generator, an overflow path of the overflow pipe is provided with a sealing mechanism, and the overflow path is connected to a concentrated solution path between the outlet side of the high temperature heat exchanger and the high pressure holding mechanism. This is a dual-effect absorption refrigeration system that is characterized by:

"Example" Embodiments of the present invention will be described using the drawings.

In FIG. 4, parts having the same reference numerals as in FIGS. 1 to 3 have similar structures and functions.

The solution flow rate control valve 10 is provided in the solution path from the high temperature generator 3 to the low temperature generator 4, and acts as a high pressure holding mechanism for maintaining the internal pressure of the high temperature generator 3 at a high pressure.

A float valve 15 is provided as a sealing mechanism at the inlet of the overflow path of the overflow pipe 17. This overflow path is connected to a return port 18 in the concentrated solution path from the outlet side of the high temperature heat exchanger 6 to the solution flow rate control valve 10 as a high pressure holding mechanism.

During operation, if the solution flow rate is not fully adjusted by the solution flow rate control valve 10 and the solution level in the high temperature generator 3 rises abnormally, the liquid level in the liquid level detection box 16 will close at the liquid level during normal operation. Gate valves such as the float valve 15 that are open perform an opening operation, and the overflow pipe 1
7, the solution is returned to the return port 18 provided at the outlet of the high temperature heat exchanger 6 to suppress the rise in the liquid level, and when the liquid level returns to normal, the float valve 15 performs a closing operation.

When the float valve 15 is closed, the pressure difference H18 between the high temperature generator 3 and the overflow pipe return port ₁₈ during normal operation reduces the flow loss of the high temperature heat exchanger _HEX
m, and if the piping flow loss during this period is H _LOSS m, then H ₁₈ = H _HEX + H _LOSS , and it is usually easy to set it to 1 m or less. Since it is very small compared to the pressure difference of 5 m when bypassing, the sealing pressure is also low, and the buoyancy required to open the float valve 15 is small, making it possible to achieve a float that is satisfied with a small diameter float ball. This has the advantage that the valve 15 has a simple structure and is inexpensive.

FIG. 5 shows another embodiment of the invention.

In FIG. 5, parts with the same numbers as in FIGS. 1 to 4 have the same structure and function. The throttle mechanism 13 acts as a high pressure holding mechanism.

The sealer capacity required when the overflow pipe 17 is not in operation is approximately 1 m solution column as described in the example shown in FIG. Therefore, it is practically possible to provide the U-shaped tube 19 as a sealing mechanism in the overflow path to prevent bypass by the liquid sealing mechanism using the solution in the system. That is, it has the advantage of providing a solution control mechanism for a high temperature generator that is simple, inexpensive, and has no moving parts and is therefore highly reliable.

FIG. 6 shows another embodiment of the invention.

In FIG. 6, parts with the same reference numerals as in FIGS. 1 to 5 indicate the same structure and operation. Overflow pipe 1
A branch pipe 20 from the discharge side of the solution pump 8 is connected between 7 and the U-shaped pipe 19, and the dilute solution before reaching the high-temperature generator 3 flows into the U-shaped pipe 19. The concentrated solution returned from the U-shaped tube 19 stays in the U-shaped tube 19 when the overflow tube 17 is not in operation, and is prevented from reaching the crystals, thereby making it possible to ensure the operation of the overflow tube 17.

A branch pipe 20 connects the solution pump 8 to the low temperature generator 4.
It is also possible to introduce a dilute solution before reaching .

FIG. 7 shows another embodiment of the invention.

In FIG. 7, parts having the same reference numerals as in FIGS. 1 to 6 have similar structures and functions.

Reference numeral 21 denotes a liquid seal box as a sealing mechanism, which is provided with a sealing mechanism to prevent bypass when the overflow pipe 17 is not in operation. Inside the liquid seal box 21, a dilute solution path is passed from the discharge side of the solution pump 8 to the inlet of the high temperature heat exchanger 6, and when the overflow pipe 17 is activated, the high temperature heat exchanger 6 is filled with the high temperature return solution of the high temperature generator 3. Heat the dilute solution sent to. As a result, when the cause of the operation of the overflow pipe 17 is crystals in the high temperature heat exchanger 6,
Crystallization work can be quickly promoted.

Since the dilute solution is mixed in the liquid seal box 21 by the dilute solution branch pipe 20, it is less likely to crystallize than in the high temperature heat exchanger 6.

"Effects of the Invention" According to the present invention, an overflow pipe that can prevent bypass with a small sealing capacity when the liquid level is normal can be provided in the high temperature generator, and a high-performance valve is not required and a complicated control mechanism is not required. It is possible to provide a dual-effect absorption refrigeration system having a liquid level control mechanism for a high-temperature generator that is simple, compact, inexpensive, and has high reliability, and has extremely great practical effects.

[Brief explanation of drawings]

Figures 1 to 3 are flow diagrams of the conventional example, and Figure 4 is a flow diagram of the conventional example.
7 are flow diagrams of embodiments of the present invention. 1...Absorber, 2...Evaporator, 3...High temperature generator, 4
...low temperature generator, 5...condenser, 6...high temperature heat exchanger,
7... Low temperature heat exchanger, 8... Solution pump, 9... Refrigerant pump, 10... Solution flow rate control valve, 11... Liquid level detector of high temperature generator 3, 12... Control device, 13... Throttle mechanism, 14... Bypass valve , 15...Float valve, 16
...Liquid level detection box, 17...Overflow pipe, 18...
Return port, 19...U-shaped pipe, 20...branch pipe, 21...liquid seal box.

Claims (1)

[Claims] 1. A dual-effect absorption refrigeration system having an evaporator, an absorber, a high-temperature and low-temperature generator, a condenser, a high-temperature and low-temperature heat exchanger, and a solution path and a refrigerant path connecting these devices, A high pressure holding mechanism for maintaining the internal pressure of the high temperature generator at a high pressure is provided in the solution path from the high temperature generator to the low temperature generator, or in the solution path from the high temperature generator to the absorber, A solution overflow pipe is provided in the high temperature generator, an overflow path of the overflow pipe is provided with a sealing mechanism, and the overflow path is connected to a concentrated solution path between the outlet side of the high temperature heat exchanger and the high pressure holding mechanism. A dual-effect absorption refrigeration device featuring: 2. The dual-effect absorption refrigeration apparatus according to claim 1, wherein the sealing mechanism is a gate valve. 3. The dual-effect absorption refrigeration apparatus according to claim 1, wherein the sealing mechanism is a liquid sealing mechanism using a solution. 4. In a dual-effect absorption refrigeration system having an evaporator, an absorber, a high-temperature and low-temperature generator, a condenser, a high-temperature and low-temperature heat exchanger, and a solution path and a refrigerant path connecting these devices, from the high-temperature generator, A high-pressure holding mechanism for maintaining the internal pressure of the high-temperature generator at a high pressure is provided in the solution path leading to the low-temperature generator or in the solution path leading from the high-temperature generator to the absorber, and a high-pressure holding mechanism is provided for maintaining the internal pressure of the high-temperature generator at a high pressure, and a solution overflow to the high-temperature generator is provided. a pipe is provided, and an overflow path of the overflow pipe is provided with a sealing mechanism, and the overflow path is connected to a concentrated solution path between the outlet side of the high temperature heat exchanger and the high pressure holding mechanism, and the sealing mechanism A dual-effect absorption refrigeration apparatus, characterized in that the dilute solution is introduced into the sealing mechanism before reaching the high-temperature or low-temperature generator. 5. In a dual-effect absorption refrigeration system having an evaporator, an absorber, a high-temperature and low-temperature generator, a condenser, a high-temperature and low-temperature heat exchanger, and a solution path and a refrigerant path connecting these devices, from the high-temperature generator, A high-pressure holding mechanism for maintaining the internal pressure of the high-temperature generator at a high pressure is provided in the solution path leading to the low-temperature generator or in the solution path leading from the high-temperature generator to the absorber, and a high-pressure holding mechanism is provided for maintaining the internal pressure of the high-temperature generator at a high pressure, and a solution overflow to the high-temperature generator is provided. a pipe is provided, and an overflow path of the overflow pipe is provided with a sealing mechanism, and the overflow path is connected to a concentrated solution path between the outlet side of the high temperature heat exchanger and the high pressure holding mechanism, and the sealing mechanism A liquid sealing mechanism according to the present invention, characterized in that the sealing mechanism is configured to exchange heat between the high temperature solution returning from the high temperature generator and the dilute solution flowing from the solution pump to the high temperature heat exchanger. Heavy-duty absorption refrigeration equipment.