JPH0355745B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an absorption refrigerator.

Conventionally, when controlling the capacity of an absorption chiller, for example, when the chilled water load decreases, the chilled water temperature is detected and the heating to the generator is automatically shut off.
Usually, the refrigerant pump also stopped at the same time.
In this case, when the chilled water load increases and the chilled water temperature rises, heating to the generator begins and the refrigerant pump also starts.

However, such conventional devices had the following drawbacks.

(1) The refrigerant pump starts and stops frequently in a short period of time. This is especially noticeable when the amount of water held in the cold water system is small.

(2) The remaining energy of the concentrated solution held in the refrigerator is not utilized.

(3) Cold water temperature fluctuates drastically.

etc.

The present invention eliminates the above drawbacks of the conventional method by continuing to operate the refrigerant pump for a predetermined period even after the chilled water load decreases and heating to the generator is cut off. It is an object of the present invention to provide an absorption refrigerator which reduces the frequency of , effectively utilizes the remaining energy of the concentrated solution, and reduces fluctuations in chilled water temperature.

The present invention has an evaporator, an absorber, a generator, and a condenser connected and arranged by a solution path and a refrigerant path, and includes a refrigerant pump for circulating refrigerant in the evaporator and a load detection mechanism for detecting a refrigerating load amount. , in an absorption refrigerator in which the amount of heating in the generator is controlled by a signal from the load detection mechanism, even after heating in the generator is stopped by a heating stop signal from the load detection mechanism, the pump is stopped. A pump control mechanism is provided, wherein the pump stop signal is issued at a load level lower than the load level at which the heating stop signal is to be issued, so that the refrigerant pump continues to operate until the signal is issued. This is an absorption chiller characterized by:

To explain the present invention with reference to the drawings, in FIG. 1, A is an absorber, G is a generator,
C is a condenser, E is an evaporator, RP is a refrigerant pump that circulates refrigerant in the evaporator E, and SP is a solution pump. These devices are connected by piping to form a solution path and a refrigerant path. R is a cold water path, S is a cooling water path, and T is a heating medium path.
These equipment paths form an absorption refrigeration cycle.

CV is a heating amount controller that controls the amount of heating by adjusting the flow rate of the heating medium, and is based on the signal from the temperature detection mechanism TC that detects the cold water temperature and issues a heating stop signal and heating start signal at a predetermined set temperature. Heating is started, stopped and controlled.

The temperature detection mechanism TC functions not only as a load detection mechanism as described above, but also as a pump control mechanism for the refrigerant pump RP. That is, a pump stop signal and a pump start signal are issued at a predetermined set temperature to stop and start the refrigerant pump RP.

Therefore, the set temperature in the temperature detector TC is as follows.

For heating stop signal>Pump stop signal For heating start signal>For pump start signal Next, the control process will be explained with reference to FIG.

This embodiment is an example of three-stage control, and the temperature control mechanism TC includes three-stage control contacts.

indicates a high load condition. When the chilled water load increases and the chilled water outlet temperature reaches 8℃, the heating amount controller
CV is maintained at an opening corresponding to high load. In this state, when the cold water outlet temperature decreases to 7° C., the heating amount controller CV changes stepwise to an opening corresponding to a low load and maintains this opening. In this way, high load and low load are controlled.

indicates a low load condition. When the cold water temperature further decreases from the region , and reaches 6° C., a heating stop signal is issued, and the heating amount controller CV is fully closed, cutting off heating to the generator G. At this point, the refrigerant pump RP is still operating. When the cold water outlet temperature rises from this state and reaches 7°C, a heating start signal is issued and heating to the generator G starts again, but the heating amount controller CV is at an opening corresponding to a low load.
This condition is maintained until the cold water rises to 8°C.
controls low load and heating cut-off.

controls the operation and stop of the refrigerant pump. When the chilled water temperature drops to 6°C in the stage state, a heating stop signal is issued and heating to the generator G is cut off, but the refrigerant pump RP continues to operate. As a result, it is possible to cope with the cold water load using the remaining capacity for producing cold water using the energy remaining in the concentrated solution inside the refrigerator.

When the chilled water temperature drops to 5° C. in this state, a pump stop signal is issued and the refrigerant pump RP is stopped. When the chilled water temperature rises to 6°C, a pump start signal is issued and the refrigerant pump RP is operated again. By operating at a cold water temperature of 5 to 6 degrees Celsius,
It is possible to cope with the chilled water load by effectively utilizing the remaining chilled water production capacity based on the remaining energy of the concentrated solution.

When the load increases and the cold water temperature rises and reaches 7°C, a heating start signal is issued and heating to the generator G is started.

As a load detection mechanism, in addition to chilled water temperature detection,
The temperature or pressure of the generator G, the temperature or pressure of the condenser C, the refrigerant level in the evaporator E, the refrigerant level in the absorber A, etc. may be detected. In that case, the pump control mechanism may use the same detection point or different detection points. However, the pump stop signal is generated at a load level lower than the load level at which the heating stop signal should be generated.
Further, the pump start signal is generated at a level lower than the load level of the heating start signal.

If the liquid level of the refrigerant in the evaporator E rises too high, it will cause cavitation of the refrigerant pump RP. Therefore, a lower limit is set and connected to the pump control mechanism, and a signal based on this lower limit level is given priority over signals from other detection terminals. may be used to issue a pump stop signal.

The temperature detection mechanism TC may have four stages, and the final stage may be a thermostat to prevent cold water from freezing.

The present invention includes a pump control mechanism in which the pump stop signal is issued at a load level lower than the load level at which the heating stop signal is to be issued. Frequent starting and stopping of the pump is prevented, and the remaining cold water production capacity from the remaining energy of the concentrated solution after heating is stopped can be effectively used to respond to the cold water load, and there is little fluctuation in the cold water temperature.
It is possible to provide an absorption refrigerator that is highly efficient and capable of smooth operation control, and has extremely great practical effects.

[Brief explanation of drawings]

FIG. 1 is a flow diagram of an embodiment of the present invention, and FIG. 2 is a control diagram thereof.

Claims (1)

[Scope of Claims] 1. A load detection mechanism that connects an evaporator, absorber, generator, and condenser through a solution path and a refrigerant path, and detects a refrigerant pump for refrigerant circulation in the evaporator and a refrigerating load amount. In the absorption refrigerator, the amount of heating in the generator is controlled by a signal from the load detection mechanism, even after heating in the generator is stopped by a heating stop signal from the load detection mechanism. , a pump control mechanism configured to cause the pump stop signal to be issued at a load level lower than the load level at which the heating stop signal should be issued, so as to cause the refrigerant pump to continue operating until the pump stop signal is issued. An absorption refrigerator characterized by: 2. An evaporator, an absorber, a generator, and a condenser are connected and arranged by a solution path and a refrigerant path, and includes a refrigerant pump for refrigerant circulation in the evaporator and a load detection mechanism for detecting a refrigerating load amount, In the absorption refrigerator, the amount of heating in the generator is controlled by a signal from a detection mechanism, and the load detection mechanism includes a chilled water temperature detector, and the amount of heating in the generator is controlled by a heating stop signal from the load detection mechanism. to cause the refrigerant pump to continue operating even after the refrigerant pump is stopped until a pump stop signal is issued;
than the cold water set temperature for the heating stop signal,
An absorption refrigerator comprising a pump control mechanism that sets a cold water temperature low in response to the pump stop signal. 3. Claims in which the pump control mechanism also includes a refrigerant liquid level detection mechanism in the evaporator, and is configured to give a pump stop signal priority over other pump stop signals than the refrigerant liquid level detection mechanism. The absorption refrigerator according to item 1 or 2.