JPH0378543B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a dual-effect absorption refrigerator, in particular, a system in which a portion of a dilute solution discharged from a solution pump is sent to a low temperature generator.
The present invention relates to a dual-effect absorption refrigerator, the remainder of which is directed to a high temperature generator.

[Prior art and its problems]

It is widely known that in order to increase the efficiency of this type of refrigerator at partial load, it is necessary to reduce the dilute solution flow rate in each of the low-temperature side dilute solution path and the high-temperature side dilute solution path. In refrigerators, bellows seal valves are commonly used as flow control valves. However, bellows seal valves are not only expensive, but also have drawbacks such as the bellows seal portion being easily damaged and having a short lifespan. In addition, small refrigerators are conventionally
Dilute solution flow control during partial loads is often not fully controlled, at the expense of energy loss.

FIG. 2 shows an example of a conventional dual-effect absorption refrigerator.

In FIG. 2, 1 is an absorber, 2 is an evaporator, 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 throttle mechanism, and 11 is a self-powered float valve, and these devices are connected through a solution path and a refrigerant path to form a refrigeration cycle. When the load becomes partial, the cold water outlet temperature of the evaporator 2 is detected by the temperature detector 12, and the control mechanism 13
throttles the heat source control valve 14. As a result of this operation, the amount of refrigerant vapor generated within the high temperature generator 3 decreases and the internal pressure decreases, so the liquid level of the solution within the high temperature generator 3 rises.
A self-powered float valve 11 throttles the flow of dilute solution supplied to the high temperature generator 3. This allows the heat source to be effectively used only for heating the minimum required amount of dilute solution.

However, since no flow rate control mechanism is provided in the dilute solution supply path to the low temperature generator 4, the same amount of dilute solution is supplied to the low temperature generator 4 even during partial load as during rated load. As a result, the refrigerant vapor generated in the high-temperature generator 3 is used to heat the dilute solution other than the required amount, resulting in a disadvantage of poor efficiency.

Alternatively, there is a method in which the self-powered float valve 11 of the high temperature generator 3 is provided at the outlet of the solution pump 8 and the flow rates of the dilute solution on the high temperature side and the low temperature side are controlled by the self-powered float valve 11.

An example is shown in FIG.

In FIG. 3, parts having the same reference numerals as in FIG. 2 have similar structural functions. In this type of refrigerator, the self-powered float valve 11 is installed outside the high-temperature generator in Fig. 3, but the self-powered float valve 11 is normally installed to prevent leakage of dilute solution to the outside of the machine. It is installed in the high temperature generator 3. For this reason, the self-powered float valve 11 that controls the flow rate of the dilute solution on the high temperature side and the low temperature side has a large flow rate, so it is necessary to use one with a large drive torque, which increases the size and requires a float ball with a large diameter. However, there is a drawback that the outer diameter of the high temperature generator 3 becomes large. Also,
Since the discharge pressure of the solution pump 8 is constantly applied to the self-powered float valve 11, especially when the self-powered float valve 11 is on the closed side, as shown in FIG. There is also the drawback that the amount of dilute solution leaking in the direction of the arrow through the shaft seal into the return line of the generator 3 becomes a non-negligible amount, resulting in a decrease in efficiency.

[Structure of the invention]

The present invention provides an absorber, an evaporator, a condenser, a low-temperature generator, a high-temperature generator, a solution heat exchanger, a solution pump, a refrigerant pump, a solution path connecting these, a refrigerant path, and a heat source control mechanism for the high-temperature generator. It has a cold water load detection mechanism for the evaporator, and is configured such that the high temperature generator heat source control mechanism controls the heating amount of the high temperature generator in stages such as high heating, low heating, and heating stop based on a signal from the cold water load detection mechanism. and a part of the dilute solution sent from the solution pump is guided to the low temperature generator via the heat exchanger, and the remaining part is guided to the high temperature generator via the heat exchanger. In the configured dual-effect absorption refrigerator, a dilute solution path is provided from the absorber to the low temperature generator via the heat exchanger, and an on-off valve and a throttle mechanism are provided in the path, The on-off valve is controlled by the low heating signal so that the amount of dilute solution sent to the low-temperature regenerator is reduced, the double-effect absorption refrigerating machine being different from the conventional dual-effect absorption refrigerating machine. The object of the present invention is to eliminate the above-mentioned drawbacks and provide a dual-effect absorption refrigerator that is efficient, inexpensive, and reliable even under partial load.

Next, an embodiment of the present invention will be explained based on FIG.

In FIG. 1, parts having the same reference numerals as those in FIG. 2 have similar structures and functions. In addition, 15 and 16 are throttle mechanisms, and 17 is a solenoid valve, and a part of the dilute solution path to the low temperature generator 4 is made into two series in parallel, with one throttle mechanism on one side.
5 is provided, and the other is provided with a throttle mechanism 16 and a solenoid valve 17, and the opening area of the throttle mechanisms 15 and 16 is set to an area that can secure the dilute solution flow rate required to be supplied to the low temperature generator 4 at the rated load (i.e. The aperture area of the aperture mechanism 10 in FIG.
The opening area is set to an area that can secure the flow rate of the dilute solution necessary to be supplied to the low temperature generator 4 during partial load. At partial load, the cold water outlet temperature of the evaporator 2 is detected by the temperature detector 12, and the control mechanism 13 throttles the heat source control valve 14 and at the same time closes the electromagnetic valve 17 using the same signal, thereby controlling the flow rate.

In addition, in the example shown in Fig. 1, the solenoid valve 17 and the throttle mechanism 16 are separated, but of course if the port diameter of the solenoid valve 17 can be appropriately selected, the throttle mechanism 16 can be omitted and the solenoid valve can be used for both purposes. You can also.
In addition, by using an opening switching type (large to small opening) solenoid valve instead of a fully open-fully closed type solenoid valve, the main dilute solution path to the low temperature generator 4 can be routed to the low temperature generator 4 without having to connect multiple lines in parallel. Able to carry out inventions.

An example is shown in FIG. Portions with the same reference numerals as those in the above figures have similar configurations and functions. Also, solenoid valve 1
8 is set to have a predetermined opening area when the opening degree is large and small. Due to the high heating signal of the control mechanism 13 of the heat source control valve 14, the solenoid valve 18
The dilute solution flow rate to the low temperature generator 4 can be controlled by increasing the opening degree and making it small by the low heating signal.

〔Effect of the invention〕

According to the present invention, since the amount of dilute solution supplied to the low-temperature generator can be appropriately reduced during partial load, it can be combined with the conventional control of the amount of dilute solution supplied to the high-temperature generator to be efficient and inexpensive during partial load. This makes it possible to provide a highly reliable dual-effect absorption refrigerator, which is extremely effective in practice.

[Brief explanation of drawings]

FIGS. 1 and 5 show flow sheets of an embodiment of the present invention, and FIGS. 2 and 3 show flow sheets of conventional examples. Moreover, FIG. 4 shows an example of the structure of a self-powered float valve. 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... Throttle mechanism, 11... Self-powered float valve, 12... Temperature detector, 13... Control mechanism, 14...
Heat source control valve, 15, 16... throttle mechanism, 17, 18
... Solenoid valve, 19... Shaft seal section.

Claims (1)

[Claims] 1. Absorber, evaporator, condenser, low-temperature generator, high-temperature generator, solution heat exchanger, solution pump, refrigerant pump, and the solution path connecting these, the refrigerant path, and the chilled water load of the evaporator. a detection mechanism, and a mechanism for controlling the heating source of the high temperature generator in stages such as high heating, low heating, and heating stop based on the signal from the load detection mechanism, and a part of the solution sent from the solution pump is In the dual-effect absorption refrigerator, the solution pump is configured to have a solution flow rate control mechanism for maintaining a liquid level in the high-temperature generator, and the remaining portion is guided to the high-temperature generator in the low-temperature generator. An on-off valve is provided in the solution path from to the low-temperature generator, and the on-off valve is operated to reduce the solution flow rate to the low-temperature generator in response to a low heating signal sent by the cold water load detection mechanism to the high temperature generator heating source control mechanism. A dual-effect absorption refrigerator characterized by: 2. The dual-effect absorption refrigerator according to claim 1, wherein the opening/closing valve is a solenoid valve, and the valve portion is configured to maintain a predetermined port diameter when the solenoid valve is energized and de-energized. 3. The dual-effect absorption refrigerator according to claim 1, wherein two solution paths to the low temperature generator are arranged in parallel, and one of the paths is provided with a flow rate limiting orifice and the other path is provided with an on-off valve.