JPS6113551B2 - - Google Patents

Description

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

An example of a conventional absorption refrigerator is shown in FIG. 1, which includes an absorber A, an evaporator E, a generator G, a condenser C, a solution heat exchanger X, a solution pump SP, and a refrigerant pump RP. Connect these devices and connect pipes 1, 2,
3, 4, 5, spray pipe 6, pipe lines 7, 8, spray pipe 9,
A conduit 10 and an expansion valve 11 are provided. A pipe line 8 on the discharge side of the refrigerant pump RP and a pipe line 1 on the suction side of the solution pump SP are a dilution circuit 1 equipped with a dilution valve SV.
Connected by 3.

Reference numeral 14 denotes a heating pipe through which a heat medium fluid such as steam is guided to heat the solution in the generator G, and the flow rate of the heat medium fluid is controlled by a heating amount control valve HV to adjust the amount of heating. . Reference numeral 15 denotes a cold water pipe, and the cold water outlet temperature is detected by a temperature detector 16, and the heating amount control valve HV is adjusted based on the signal. 17 and 18 are cooling water pipes.

19 is a float switch which acts as a concentration equivalent value detection device that indirectly detects the concentration of the solution by detecting the refrigerant liquid level in the evaporator E, detects the danger level of crystals, and uses the danger signal to dilute the liquid. valve
It is now possible to operate SV.

In such conventional systems, in order to prevent over-concentration of the solution during operation, the float switch 19 estimates the solution concentration and determines the liquid level height corresponding to the concentration that may cause crystallization. When detected, a signal is generated to open the normally closed dilution valve SV to mix refrigerant into the solution to dilute the solution and prevent crystallization due to overconcentration.

However, in the past, whether dilution was performed by opening the dilution valve SV or by changing the opening degree of the heating amount control valve HV, the opening degree of the heating amount control valve HV was determined based on the chilled water load at that time. It remains at the corresponding opening. On the other hand, at full load, the heating amount control valve
The HV is fully open, and there is generally a high possibility that overconcentration will occur at full load, in which case a danger signal will be issued and dilution will be performed, but the heating amount control valve HV remains fully open. .

If it is necessary to dilute in this way,
In many cases, the heating amount control valve HV is fully open or considerably open, so the dilution circuit 13
There was a waste of diluting the solution in the generator G while concentrating the solution in the generator G. In addition, dilution valve SV
When determining the size of the refrigerant, determine the amount of refrigerant that is greater than or equal to the amount of refrigerant that is heated and separated by generator G when the heating amount control valve HV is fully open and heating medium equivalent to 100% load is supplied to generator G. However, the dilution valve SV had to be large enough to be transferred from the refrigerant system to the solution system, which resulted in a large dilution valve SV.

The present invention detects the degree of risk of crystal formation, operates a dilution circuit based on the detection signal to dilute the solution, and operates the heating amount adjustment mechanism of the generator to reduce the heating amount to a predetermined level. By controlling the amount of heating to a low level, it eliminates the above-mentioned drawbacks of conventional products, and also reduces the concentration effect of the solution during dilution, prevents wasted energy consumption, and allows the dilution to be performed effectively in a short time. It is an object of the present invention to provide an absorption refrigerator in which the dilution valve can be made small.

The present invention provides evaporators, absorbers, generators, condensers,
In an absorption refrigerator in which a solution cycle and a refrigerant cycle are formed by a solution heat exchanger, a heating amount adjustment mechanism in the generator, a refrigerant pump, a solution pump, and a path connecting the equipment, the refrigerating capacity and the load amount are A capacity control mechanism is provided for controlling the heating amount adjusting mechanism by giving a capacity control signal to the heating amount adjusting mechanism according to the relative relationship between the heating amount adjusting mechanism, and a dilution control valve for controlling the refrigerant liquid part in the refrigerant cycle and a part in the solution cycle. a dilution circuit connected through the solution cycle, and a crystallization risk detection device for detecting a crystallization risk of the solution during the solution cycle, the crystallization risk detection device detecting a risk exceeding a predetermined risk. a danger signal is issued, and the dilution control valve is opened by the danger signal to dilute the concentrated solution, and the heating amount adjustment mechanism is controlled by the danger signal in priority to the volume control signal. The absorption refrigerator is characterized in that the amount of heating is reduced to a predetermined low amount of heating.

The present invention will be explained with reference to the drawings based on examples.
In FIG. 2, parts with the same reference numerals as in FIG. 1 indicate the same parts. However, in this embodiment, in order to perform capacity control during normal operation, the chilled water outlet temperature is detected by the temperature detector 16, the relative relationship between the refrigerating capacity and the load amount is detected, and this relative relationship is detected. In addition to being equipped with a capacity control mechanism in which the heating amount control valve HV is operated by a capacity control signal sent in response to the In an emergency, a danger signal from a float switch 19 serving as a crystal danger detection device activates the dilution circuit 13 and reduces the opening degree of the heating amount control valve HV to reduce the amount of heating.

That is, the refrigerant liquid level detection mechanism in the evaporator E using the float switch 19 is a concentration equivalent value detection device that indirectly detects the solution concentration during the solution cycle based on the height of the liquid level. This device acts as a crystal danger detection device to detect the crystal danger level, and when the crystal danger level exceeds a predetermined danger level (i.e., when the concentration exceeds a certain predetermined concentration, that is, when the refrigerant liquid level in the evaporator E is , the height is exceeded), a danger signal is issued. Therefore, this dangerous signal is configured to have priority over the capacity control signal from the temperature detector 16, and when this dangerous signal is received, the heating amount control valve HV controls the capacity control signal from the temperature detector 16. Regardless of the opening, the opening is narrowed down to a predetermined small opening and a predetermined low heating amount is maintained.

If the solution becomes overconcentrated during operation of the absorption refrigerator, the liquid level in the evaporator E will rise and the float switch 19 will be activated.
is activated and issues a danger signal, and this danger signal opens the dilution valve SV to perform dilution. At the same time, the heating amount control valve HV is throttled to a predetermined small opening and a low heating amount, thereby saving wasted energy. prevent consumption,
Further, the dilution operation can be performed reliably in a short period of time.

When the frozen liquid level in the evaporator E falls to a predetermined level due to the dilution action, it is detected by another float switch (not shown), or after a certain period of time has elapsed after dilution, the dilution valve SV is activated by a timer or the like. When fully closed, the opening limit of the heating amount control valve HV is canceled and the heating amount control valve HV is controlled by the capacity control signal from the temperature sensor 16 related to the chilled water load. It is done.

Zero opening (fully closed) may be selected as the predetermined small opening of the heating amount control valve HV during dilution.
In this case, only dilution by the dilution circuit 13 is performed without heating and concentrating in the generator G (the solution pump SP, refrigerant pump RP, etc. continue to operate), and the refrigerant in the evaporator E is Upon detection of a decrease in the liquid level or detection of the passage of time by a timer, the dilution valve SV is closed and the normal operating state is returned to, in which the heating amount control valve HV is controlled by the capacity control signal from the temperature detector 16.

As the solution concentration equivalent value, the evaporator E as described above is used.
In addition to the refrigerant liquid level in the absorber A, the solution level in the generator G, etc. may be detected singly or in combination.In addition, the concentration meter may be used to detect the absorber A, generator G, and return pipe. The concentration of the solution at one or more locations within the solution heat exchanger X, etc. may be directly detected.

Since the crystallization conditions of a solution are determined by the relationship between concentration and temperature, if the degree of danger is detected only by concentration as in the above example, the dangerous concentration will be determined based on the worst or near worst low temperature conditions. If the temperature is high, dilution will occur more than necessary, resulting in a decrease in refrigerating capacity. In order to prevent this, we detect the solution temperature or a temperature equivalent value that can estimate the solution temperature, and combine that danger signal with the danger signal from the detection of the concentration or concentration equivalent value. It is also possible to control the concentration in stages or continuously by setting the dangerous concentration value. The temperature of the solution is detected in absorber A, generator G, pipes 4 and 5, solution heat exchanger X, etc., and the temperature equivalent value is detected in absorber A, generator The steam pressure inside the vessel G is detected. These detections may be performed alone or in combination.

When the generator G is a direct-fired type, the heating amount adjustment mechanism corresponds to a flow control valve for liquid or gaseous fuel.

The present invention provides evaporators, absorbers, generators, condensers,
In an absorption refrigerator in which a solution cycle and a refrigerant cycle are formed by a solution heat exchanger, a heating amount adjustment mechanism in the generator, a refrigerant pump, a solution pump, and a path connecting the equipment, the refrigerating capacity and the load amount are A capacity control mechanism is provided for controlling the heating amount adjusting mechanism by giving a capacity control signal to the heating amount adjusting mechanism according to the relative relationship between the heating amount adjusting mechanism, and a dilution control valve for controlling the refrigerant liquid part in the refrigerant cycle and a part in the solution cycle. a dilution circuit connected through the solution cycle, and a crystallization risk detection device for detecting a risk of causing a crystallization risk of the solution during the solution cycle, the crystallization risk detection device detecting a predetermined risk of crystallization of the solution during the solution cycle. When detected, a danger signal is issued, and the dilution control valve is opened by the danger signal to dilute the concentrated solution, and the heating amount adjustment mechanism is controlled by the danger signal with priority over the capacity control signal. Since the amount of heating is reduced and the heating amount is reduced to a predetermined low amount, the danger of crystallization of the solution is increased, and heating concentration in the generator is suppressed during the dilution operation, resulting in wasted energy. Since the consumption of refrigerant is prevented, the dilution operation is performed reliably in a short period of time, and the generation of refrigerant vapor is suppressed during dilution, the amount of refrigerant returned to the evaporator E is small, so the dilution valve SV can be of small capacity. It is possible to provide an absorption refrigerating machine that has advantages, and has extremely large practical effects.

[Brief explanation of the drawing]

FIG. 1 shows a flowchart of a conventional example, and FIG. 2 shows a flowchart of an embodiment of the present invention. 1...Pipeline, 2...Pipeline, 3...Pipeline, 4...Pipeline, 5
...pipe line, 6...dispersion pipe, 7...pipe line, 8...pipe line, 9...
Spreading pipe, 10... Pipe line, 11... Expansion valve, 13... Dilution circuit, 14... Heating tube, 15... Cold water pipe, 16... Temperature detector, 17... Cooling water pipe, 18... Cooling water pipe, 19
...float switch, A...absorber, G...generator,
C... Condenser, E... Evaporator, X... Solution heat exchanger,
SP...solution pump, RP...refrigerant pump, HV...heating amount control valve, SV...dilution valve.

Claims (1)

[Claims] 1. A solution cycle and a path connecting the evaporator, absorber, generator, condenser, solution heat exchanger, heating amount adjustment mechanism in the generator, refrigerant pump, solution pump, and equipment. An absorption refrigerator having a refrigerant cycle is provided with a capacity control mechanism that controls the heating amount adjusting mechanism by giving a capacity control signal to the heating amount adjusting mechanism according to the relative relationship between the refrigerating capacity and the load amount, and A dilution circuit is provided which connects the refrigerant liquid part of the refrigerant and a part of the solution cycle via a dilution control valve, and a crystal risk detection device is provided to detect the crystal risk of the solution in the solution cycle. , the crystal danger level detection device issues a danger signal when detecting a danger level exceeding a predetermined danger level, the danger signal opens the dilution control valve to dilute the concentrated solution, and the danger signal An absorption refrigerating machine characterized in that the heating amount adjusting mechanism is controlled by a signal with priority over the capacity control signal to reduce the heating amount to a predetermined low heating amount. 2. The absorption refrigerator according to claim 1, wherein the heating amount adjustment mechanism is a flow rate control valve for a heating heat medium fluid that heats the generator. 3. The absorption refrigerator according to claim 1, wherein the heating amount adjustment mechanism is a mechanism that adjusts the amount of heat exchange by changing the heat transfer area by adjusting the level of the solution in the generator. 4. The absorption refrigerator according to claim 1, wherein the crystal risk detection device is a concentration equivalent value detection device that directly or indirectly detects the solution concentration during the solution cycle. 5. The crystal danger detection device is also equipped with a temperature equivalent value detection device that directly or indirectly detects the solution during the solution cycle, and the danger signal is detected by the combination of the detected concentration equivalent value and temperature equivalent value. An absorption refrigerator according to claim 4, which is configured to emit. 6. The absorption refrigerator according to claim 1, wherein the predetermined low heating amount is zero. 7. The absorption refrigerator according to claim 4, wherein the concentration equivalent value detection device is a refrigerant liquid level detection device in the evaporator.