JPS5845451A - Refrigerant amount adjustment device in refrigeration equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a refrigerant amount adjusting device that can change the amount of refrigerant circulating in a refrigerant circuit in response to a change in load, and can exhibit the maximum refrigerating capacity according to the load. It is something.

Conventionally, a refrigeration system equipped with a refrigerant amount adjustment device has a compressor a, a condenser S, a throttle device C9, an evaporator d, as shown in FIG.
are connected in an annular manner, and the refrigerant amount adjusting container e is connected to a connecting position q in the middle of the throttling device C, or between the throttling device C and the evaporator d, and the compressor a and the evaporator di A configuration is known in which a connecting suction pipe f passes through a refrigerant amount adjustment container e.

In such a configuration, the refrigerant at the connection position q between the expansion device C and the refrigerant amount adjustment container e is in a gas-liquid two-phase saturated state. Therefore, if the suction pipe f does not penetrate the refrigerant amount adjustment container e, the state of the refrigerant inside the refrigerant amount adjustment container e is the same as that of the refrigerant at the connection position q between the throttle device iC and the refrigerant amount adjustment container e. Become saturated. However, when the suction pipe f passes through the refrigerant amount adjustment container e, the temperature of the suction pipe amount is normally determined at the connection point between the throttle device C and the refrigerant amount adjustment container e.
, q, a portion of the refrigerant inside the refrigerant amount adjustment container e condenses. Therefore, the humidity υ degree of the refrigerant inside the refrigerant amount adjustment container e is greater than the humidity 9 degrees of the refrigerant at the connection position q between the expansion device C and the refrigerant amount adjustment container e. If the temperature of the pick and suction pipe f is lower than the temperature of the connection position q, the refrigerant is simply accumulated in the refrigerant amount adjustment container θ.

The change in the state of the refrigerant inside the refrigerant amount adjusting container e described above with respect to the load will be explained using FIG. 2.

When considering the heat balance of the refrigerant amount adjustment container e, the main amount of heat is the amount of heat that enters the refrigerant amount adjustment container e by heat transfer from the air around the refrigerant amount adjustment container e, and the amount of heat that penetrates the refrigerant amount adjustment container e. There is an amount of heat removed from the refrigerant amount adjustment container θ by the suction pipe f. Fig. 2 shows the heat balance of the refrigerant amount adjustment container e with respect to load fluctuations of the refrigeration equipment, with the horizontal axis representing the magnitude of the load on the refrigeration system and the vertical axis representing the amount of heat entering the refrigerant amount adjustment container e. This is what I did. However, the fact that the amount of heat entering is negative means that the amount of heat is taken away from the refrigerant amount adjustment container e. In FIG. 2, a curve q1 shows the change in the amount of heat entering from the ambient air with respect to the load, and a curve q2 shows the change in the amount of heat entering from the suction pipe f with respect to the load. Then, the total amount of heat that enters the refrigerant amount adjustment container e is the amount of heat obtained by adding ql and 92, and
This total amount of heat intrusion is represented by curve q3. here,
Point I on the curve q5 means that there is no amount of heat entering the refrigerant amount adjustment container e.

By the way, the case where the refrigerant amount adjusting container e performs the function of adjusting the refrigerant amount is only when the load at point X is approximately the center and the load fluctuates within a certain range before and after it.

This is because when the load becomes considerably larger than the load at point The mass of the refrigerant accumulated inside the refrigerant amount adjustment container e does not change at all. Conversely, when the load becomes much smaller than the load at point Only the degree of supercooling changes, and there is almost no change in the mass of the refrigerant accumulated inside the refrigerant amount adjustment container e. However, the typical load range in which the refrigeration system is used is the range shown by points m and n in FIG. This means that the normal load range in which the refrigeration system is used will be much lower than the load experienced at point I.

As is clear from the above explanation, in the normal load range in which the refrigeration system is used, the interior of the conventional refrigerant amount adjustment container e is occupied by supercooled liquid, and the refrigerant amount is limited only in extremely large load ranges. The drawback is that the refrigerant amount adjustment function is not achieved within the normal load range in which the refrigeration system is used. Particularly when the load is low, the compressor suffers from fluid deterioration.

Therefore, the present invention provides a discharge pipe connecting a compressor and a condenser;
Alternatively, a branch pipe branched from the discharge pipe can be placed in the refrigerant amount adjustment container for heat exchange to increase the amount of heat that enters the refrigerant amount adjustment container. By changing the amount of refrigerant flowing through the refrigeration system, it is possible to always make the refrigeration system perform at its maximum capacity in response to the load.

An embodiment of the present invention will be explained with reference to FIGS. 3 and 4. FIG. As shown in FIG. 3, a compressor 1, a condenser 2, a throttle device 3, and an evaporator 4 are each connected in a ring. The refrigerant amount adjustment container 6 is connected to a connection position 3a in the middle of the throttling device 3. Further, the suction pipe 6 connects the compressor 1 and the evaporator 4. Further, a branch pipe 7a is provided in the discharge pipe 7 that connects the compressor 1 and the condenser 2, and one end of this branch pipe 7a is connected to a branch point 7b in the middle of the discharge pipe 7.
The other end is connected to a confluence point 7c located in the middle of the discharge pipe 7 on the condenser 2 side as well as the branch point 7b. Further, as shown in FIG.

The operation of the refrigerant amount adjusting device described above will be explained below.

Generally, the temperature of the suction pipe 6 is sensitive to load fluctuations.
In addition, although the temperature changes greatly, the temperature at the connection position 3a between the refrigerant amount adjustment container 6 and the throttling device 3 does not change very much.

Now, assume that the refrigerant is filled with the necessary refrigerant so that the refrigeration system exhibits its maximum capacity under certain design heat load conditions. When the refrigeration system is operated under a certain load condition, the temperature of the suction pipe 6 is also maintained at a certain temperature. At this time, the temperature of the suction pipe 6 penetrating the refrigerant amount adjustment container 6 is lower than the temperature at the connection position 3a between the refrigerant amount adjustment container 6 and the expansion device 3, and the temperature of the branch pipe 7a is lower than the temperature at the connection position 3a between the refrigerant amount adjustment container 6 and the expansion device 3. higher than the temperature at position 3a. Therefore, the temperature of the refrigerant inside the refrigerant amount adjustment container 5 is lower than that of the refrigerant amount adjustment container 5.
Although the saturation temperature is equal to the temperature of the refrigerant at the connection position 3a with the expansion device 3, the wetness of the refrigerant inside the refrigerant amount adjustment container 6 and the refrigerant at the connection position 3a are different. When adjusting the amount of refrigerant, it is important to adjust the wetness of the refrigerant inside the refrigerant amount adjustment container 6. In other words, since the difference in specific weight between the gas state and the liquid state of the refrigerant is large, the amount of refrigerant cannot be adjusted. Controlling the proportion of the liquid phase of the refrigerant inside the container 5 is important. In FIG. 5, the diameter of the branch pipe 7a is plotted on the horizontal axis, and the humidity of the refrigerant inside the refrigerant amount adjustment container 6 is plotted at 9 degrees on the vertical axis.
It shows the ratio of the liquid phase of the refrigerant inside the refrigerant amount adjustment container 5 under a certain design heat load condition. For example, the fifth
In the figure, if a branch pipe 7a with a pipe diameter indicated by point h is used, under the design load conditions, the refrigerant amount adjustment container 6
The wetness of the refrigerant inside is i. The wetness of the refrigerant inside the refrigerant amount adjusting container 6 can be determined by appropriately selecting the pipe diameter of the branch pipe 7a, as described above, or by using the following method. As shown in FIG. 6, by providing fins 8 on the suction pipe 6 and the branch pipe 7a and changing their heat transfer areas, the wetness of the refrigerant inside the refrigerant amount regulating container 6 can be appropriately selected.

Next, the operation of the refrigerant amount adjusting device when the load fluctuates will be explained. First, considering the case where the load decreases, an excess amount of refrigerant will be circulating in the refrigerant circuit than the amount of refrigerant that allows the refrigeration system to achieve its maximum capacity under this load condition.
Refrigerant with almost no superheat is sucked into the compressor 1 through the suction pipe 6. Alternatively, part of the refrigerant will be sucked into the compressor 1 through the suction pipe 6 while remaining in liquid form,
The temperature of the suction pipe 6 becomes lower than before the load is reduced. Furthermore, if the load decreases, the temperature of the refrigerant discharged from the compressor 1 generally decreases, and the temperature of the branch pipe 7a also decreases. In this way, when the load decreases, both the temperature of the suction pipe 6 passing through the refrigerant amount adjustment container 6 and the lower part of the branch pipe a decrease. Therefore, the refrigerant in a saturated vapor state inside the refrigerant amount adjustment container 5 condenses, so that the wetness of the refrigerant inside the refrigerant amount adjustment container 6 increases, and the proportion of the liquid phase of the refrigerant increases. As a result, the mass of the refrigerant contained inside the refrigerant amount adjustment container 6 increases compared to before the load change. This increased refrigerant is the refrigerant that has flowed into the refrigerant amount adjustment container 6 from the connection position 3a in the middle of the expansion device 3, so that the excess refrigerant in the refrigerant circuit has been removed. As a result, the temperature of the suction pipe 6 rises to balance the temperature of the connection position 3a.

Next, the operation of the refrigerant amount adjusting device when the load increases will be explained. When the load increases, the amount of refrigerant circulating in the refrigerant circuit becomes insufficient than the amount of refrigerant that allows the refrigeration system to exhibit its maximum capacity under this load condition. , will be sucked into the compressor 1.

In other words, the temperature of the suction pipe 6 becomes higher than before the load change. Furthermore, as the load increases, the temperature of the refrigerant discharged from the compressor 1 generally increases, so the temperature of the branch pipe 7a also increases. In this way, if the load increases, the temperatures of both the suction pipe 6 and the branch pipe 7a that pass through the refrigerant amount adjustment container 5 will increase. For this reason, the refrigerant in a saturated liquid state inside the refrigerant amount adjustment container 5 evaporates, so the wetness of the refrigerant inside the refrigerant amount adjustment container 5 decreases, and the proportion of the liquid phase of the refrigerant decreases. As a result, the mass of the refrigerant contained inside the refrigerant amount adjustment container 6 decreases compared to before the load change. This decreased refrigerant eventually flows from the connection position 3a in the middle of the expansion device 3 to the refrigerant inside the refrigerant amount adjustment container 6.
Since the refrigerant has flowed into the refrigerant circuit, the refrigerant is replenished into the refrigerant circuit that was in short supply, and the temperature of the suction pipe 6 decreases and becomes equal to the temperature of the connecting position 3a in the middle of the expansion device 3. It will balance out.

The change in the state of the refrigerant inside the refrigerant amount adjusting container 6 described above with respect to the load will be explained using FIG. 7.

When considering the heat balance of the refrigerant amount adjustment container 6, as explained in the conventional example, the main amount of heat is the amount of heat that enters the refrigerant amount adjustment container 6 due to heat transfer from the air around the refrigerant amount adjustment container 6. , and the amount of heat taken from the refrigerant amount adjustment container 6 by the suction pipe O penetrating the refrigerant amount adjustment container 5. Furthermore, in the present invention, there is an amount of heat that enters the refrigerant amount adjustment container 5 from the branch pipe 7a penetrating the refrigerant amount adjustment container 6.

In FIG. 7, the horizontal axis represents the magnitude of the load on the refrigeration equipment, and the vertical axis represents the amount of heat entering the refrigerant amount adjustment container 5, and the heat balance of the refrigerant amount adjustment container 5 with respect to load fluctuations of the refrigeration equipment is calculated. This is what was explained. However, the fact that the amount of invading heat is negative means that the amount of heat is taken away from the refrigerant amount adjustment container 6. In FIG. 7, a curve q4 shows the change in the amount of heat entering from the ambient air with respect to the load, and a curve q5 shows the change in the amount of heat entering from the suction pipe 6 with respect to the load. moreover,
- The curve q6 shows the change in the amount of heat entering from the branch pipe 7a with respect to the load. Further, the total amount of heat that enters the refrigerant amount adjustment container 5 is the sum of q4, 95, and 96, and this total amount of heat that enters is represented by a curve q7. A point y on the curve q7 indicates that no amount of heat has entered the refrigerant amount adjustment container 5.

Now, in FIG. 7, if the normal load under which the refrigeration equipment is used is applied in the range of points m and n, then the fifth
As explained in the figure, by appropriately selecting the pipe diameter of the branch pipe 7a, it is possible to position the point y' on the curve q7 between the points m and n, which are the normal load range. Become.

Next, FIG. 8 shows another embodiment of the refrigerant amount adjusting device according to the present invention. The difference between FIG. 3 and FIG. 8 described above is that in FIG. 3, the discharge pipe 7 connecting the compressor 1 and the condenser 2
It is characterized in that the branch pipe Ta branched from the refrigerant amount adjustment container 6 is passed through the refrigerant amount adjustment container 6, and in FIG. It is characterized by the fact that it has a 6-penetration hole.

The refrigerant amount adjusting device shown in FIG. 8 also provides the same effects as the previous embodiment. Here, the same parts as in FIG. 3 are given the same numbers and their explanation will be omitted.

In the examples shown in Figures 3, 4, 6, and 8, a discharge pipe 7'' that connects the compressor 1 and the condenser 2, or a discharge pipe branched from the discharge pipe 7 is The branch pipe 7a and the suction pipe 6 are passed through the refrigerant amount adjustment container 6, but the meaning of this blind passage is that the discharge pipe 7, or the branch pipe 7& and the suction pipe 6 Therefore, the discharge pipe 7 or the branch pipe 7a and the suction pipe 6 are arranged to be brought into contact with the refrigerant amount adjustment container 6 to exchange heat. You may have them set up.

As described above, the refrigerant amount adjusting device of the present invention has a compressor, a condenser, a throttling device, and an evaporator tube connected in a ring, and the refrigerant amount adjusting container is placed at a connecting position in the middle of the throttling device, or between the throttling device and the evaporator. A discharge pipe connected between the compressor and the condenser, or a branch pipe branched from the discharge pipe, a suction pipe, and a container for controlling the amount of refrigerant arranged for heat exchange. It is. Therefore, the refrigerant amount can be adjusted over a wider range of load fluctuations than conventional refrigerant amount adjustment devices.

Furthermore, unlike conventional refrigerant amount adjustment devices, a discharge pipe that connects the compressor and the condenser, or a branch pipe that is a branched part of the discharge pipe, is arranged in the refrigerant amount adjustment container for heat exchange. Therefore, by appropriately selecting the diameter of the discharge pipe or the diameter of the branch pipe, it is possible to arbitrarily select the amount of refrigerant that can be stored in the refrigerant amount adjustment container under the design load condition.

Therefore, there is an advantage that the size of the refrigerant amount adjustment container can be easily determined so that the refrigerant amount adjustment function can be sufficiently performed for the maximum load condition and the minimum load condition considered at the time of design.

Furthermore, the refrigerant amount adjusting device according to the present invention has the advantage that it can completely prevent liquid from returning to the compressor, since it can sufficiently adjust the amount of refrigerant especially during low loads.

[Brief explanation of drawings]

FIG. 1 is a diagram of a refrigeration cycle equipped with a conventional refrigerant amount adjustment device, FIG. 2 is an explanatory diagram showing the heat balance of the refrigerant amount adjustment container, and FIG. 3 is a diagram of a refrigerant amount adjustment device according to an embodiment of the present invention. FIG. 4 is an enlarged partial cross-sectional view showing the refrigerant amount adjustment container used in the present invention; FIG. 6 is an explanatory diagram showing the wetness of the refrigerant in the refrigerant amount adjustment container; FIG. 6 7 is a sectional view showing another example of the refrigerant amount adjustment container, FIG. 7 is an explanatory diagram showing the heat balance of the refrigerant amount adjustment container in one embodiment of the present invention, and FIG.
The figure is a refrigeration cycle diagram in another embodiment of the present invention. 1... Compressor, 2... Condenser, 3...
... Throttle device, 4... Evaporator, 6...
...Refrigerant amount adjustment container, 6... Suction pipe, 7...
...Discharge pipe, 7a... Branch pipe. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A compressor, a condenser, a throttling device, and an evaporator are each connected in a ring, and a refrigerant amount adjusting container is connected in the middle of the throttling device or between the throttling device and the evaporator, and the amount of refrigerant is adjusted. A discharge pipe that connects the compressor and the condenser, or a branch pipe branched from the discharge pipe, and a suction pipe that connects the evaporator and the compressor are arranged in the regulating container for heat exchange. A refrigerant amount adjustment device in a refrigeration system.