JPS6240634B2 - - Google Patents

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 connects a compressor a, a condenser b, a throttle device c, and an evaporator d in a ring, and throttles a refrigerant amount adjustment container e, as shown in Fig. 1. At connection position g in the middle of device c,
Alternatively, a configuration is known in which a suction pipe f is connected between the throttle device c and the evaporator d, and further connects the compressor a and the evaporator d, through the refrigerant amount adjustment container e.

In such a configuration, the refrigerant at the connection position g 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 g between the expansion device c and the refrigerant amount adjustment container e. Become saturated. However, the suction pipe f is
If the suction pipe f passes through the
Since the temperature is lower than that of , a part of the refrigerant inside the refrigerant amount adjustment container e condenses. Therefore, the wetness of the refrigerant inside the refrigerant amount adjusting container e is greater than the wetness of the refrigerant at the connection position g between the expansion device c and the refrigerant amount adjusting container e. In other words, when the temperature of the suction pipe f is lower than the temperature of the connection position g,
The refrigerant is simply accumulated in the refrigerant amount adjustment container e.

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 due to heat transfer from the air around the refrigerant amount adjustment container e, and the amount of heat that enters the refrigerant amount adjustment container e. There is an amount of heat taken away from the refrigerant amount adjustment container e by the suction pipe f passing through the refrigerant amount adjusting container e. Fig. 2 shows the heat balance of the refrigerant amount adjustment container e with respect to load fluctuations of the refrigeration device, with the horizontal axis representing 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 represents a change in the amount of heat entering from the surrounding air with respect to the load, and a curve q2 represents a change in the amount of heat entering from the suction pipe f with respect to the load. The total amount of heat that enters the refrigerant amount adjustment container e is the sum of q1 and q2, and this total amount of heat that enters is represented by a curve q3. here,
A point x on the curve q3 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 changes within a certain range around the load represented by the point x. This is because when the load is much larger than the load at point x, the refrigerant amount adjustment container e
The refrigerant inside the refrigerant is always in a superheated vapor state, and even if there is a load change, only the degree of superheating of the refrigerant inside the refrigerant amount adjustment container e changes, and the refrigerant accumulated inside the refrigerant amount adjustment container e There is almost no change in the mass of On the other hand, when the load becomes much smaller than the load at point Only the degree of cooling 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. In other words, the normal load range in which the refrigeration system is used is considerably lower than the load represented by point x.

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 adjusted only in an extremely large load range. It has the disadvantage that it does not perform the function of regulating the amount of refrigerant within the normal load range in which the refrigeration system is used. Particularly at low loads, the disadvantage was that liquid returned to the compressor.

Therefore, the present invention solves the above-mentioned conventional drawbacks, and enables refrigerant circuits to be used in large load ranges, normal load ranges in which refrigeration equipment is used, as well as low load ranges and load fluctuations in all load ranges. By changing the amount of refrigerant flowing through the system, it is possible to always make the refrigeration system perform at its maximum capacity depending on the load.

An embodiment of the present invention is shown in FIGS. 3, 4 and 5.
This will be explained using figures. 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. A first refrigerant amount adjustment container 5 is connected to a first connection position 3a in the middle of the expansion device 3, and a second connection position 3b located between the first connection position 3a and the evaporator 4 is connected to a first connection position 3a. is connected to the second refrigerant amount adjustment container 6. In addition, the suction pipe 8 is
A compressor 1 and an evaporator 4 are connected. Further, a branch pipe 7a is provided in the connecting pipe 7 that connects the condenser 2 and the throttle device 3, and one end of this branch pipe 7a is
It is connected to a branch point 7b in the middle of the connecting pipe 7, and the other end of the branch pipe 7a is connected to a confluence point 7c in the middle of the connecting pipe 7, which is located closer to the throttle device 3 than the branch point 7b. ing. Furthermore, as shown in FIG. 4, the suction pipe 8 and the branch pipe 7a each penetrate the first refrigerant amount regulating container 5, and as shown in FIG. It also passes through the refrigerant amount adjustment container 6.

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

Generally, the temperature of the suction pipe 8 changes sensitively and greatly with respect to load fluctuations, but the temperature at the connection position 3a between the first refrigerant amount adjustment container 5 and the expansion device 3 and the second refrigerant amount change. The temperature at the connection position 3b between the regulating container 6 and the expansion device 3 does not change much. Moreover, the mass of the refrigerant accumulated in the first refrigerant amount adjustment container 5 and the second refrigerant amount adjustment container 6 is determined by the difference between the temperature of the suction pipe 8 and the temperature of the first connection position 3a, and the mass of the refrigerant accumulated in the first refrigerant amount adjustment container 5 and the second refrigerant amount adjustment container 6. 8 and the temperature at the second connection position 3b. Furthermore, the second connection position 3b
is located closer to the evaporator 4 than the first connection position 3a. That is, since the saturation temperature of the second connection position 3b is always lower than the saturation temperature of the first connection position 3a, both the first refrigerant amount adjustment container 5 and the second refrigerant amount adjustment container 6 have the same suction pipe 8. However, the humidity of the refrigerant inside the second refrigerant amount adjustment container 6 is always lower than the humidity of the refrigerant inside the first refrigerant amount adjustment container 5.

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. Assuming that the refrigeration system is operated under a certain load condition, the temperature of the suction pipe 8 is also maintained at a certain constant temperature. At this time,
Suction pipe 8 passing through the first refrigerant amount adjustment container 5
The temperature of the first refrigerant amount adjusting container 5 and the expansion device 3
than the temperature of the first connection position 3a, which is continuous with
It becomes high when the load is large, and becomes low when the load is normal or low. Further, the temperature of the branch pipe 7a is higher than the temperature of the first connection position 3a.
Therefore, the temperature of the refrigerant inside the first refrigerant amount adjustment container 5 becomes higher than the temperature of the refrigerant at the first connection position 3a when the load is high, and becomes lower when the load is low. Further, under normal load, the refrigerant inside the first refrigerant amount adjustment container 5 is transferred to the first connection position 3.
Although the saturation temperature is equal to the temperature of the refrigerant at point a, the wetness of the refrigerant inside the first refrigerant amount adjustment container 5 and the refrigerant at the first connection position 3a are different.

Further, the temperature of the suction pipe 8 penetrating the second refrigerant amount adjustment container 6 is higher than the temperature at the second connection position 3b under normal load or high load, but under low load. In this case, the suction pipe 8 is at approximately the same temperature as the second connection position 3b. Therefore, the temperature of the refrigerant inside the second refrigerant amount adjustment container 6 becomes higher than the temperature of the refrigerant at the second connection position 3b under normal load or high load. In addition, at low load, the refrigerant inside the second refrigerant amount adjustment container 6 exhibits a saturation temperature equal to the temperature of the refrigerant at the second connection position 3b, but the refrigerant inside the second refrigerant amount adjustment container 6 The humidity of the refrigerant at the second connection position 3b is different from that of the refrigerant at the second connection position 3b.

When adjusting the amount of refrigerant, it is important to adjust the wetness of the refrigerant inside the first refrigerant amount adjustment container 5 and the second refrigerant amount adjustment container 6. In other words, the refrigerant is in a gas state and a liquid state. Because the difference in specific weight is large, the first refrigerant amount adjustment container 5 and the second refrigerant amount adjustment container 6
It is important to control the proportion of the liquid phase of the refrigerant inside the refrigerant.

In FIG. 6, the diameter of the branch pipe 7a is plotted on the horizontal axis, and the wetness of the refrigerant inside the first refrigerant amount adjustment container 5 is plotted on the vertical axis. This figure shows the ratio of the liquid phase of the refrigerant inside one refrigerant amount adjustment container 5. For example, in Figure 6, h
Assuming that the branch pipe 7a having the pipe diameter shown by the dot is used, the wetness of the refrigerant inside the first refrigerant amount adjustment container 5 is i under the design heat load conditions. In this way, under certain design heat load conditions, the branch pipe 7
By appropriately selecting the pipe diameter of a, the wetness of the refrigerant inside the first refrigerant amount regulating container 5 can be appropriately selected.

Next, the operation of the refrigerant amount adjusting device in a normal load range in which the refrigeration system is used will be explained.

Assume that the refrigeration system is currently being operated under a certain load (eg, design heat load conditions). The wetness of the refrigerant inside the first refrigerant amount adjustment container 5 (in other words, the mass of the refrigerant contained inside the first refrigerant amount adjustment container 5) is determined by can be selected arbitrarily by appropriately selecting the pipe diameter. Therefore, the refrigerant inside the first refrigerant amount adjustment container 5 is in a certain gas-liquid two-phase saturated state. In addition, in the case of normal load, as explained earlier, the temperature of the suction pipe 8 penetrating the second refrigerant amount adjustment container 6 is considerably higher than the temperature of the second connection position 3b. The inside of the refrigerant amount adjusting container 6 is occupied by superheated steam.

A case in which the load increases from the above load within the normal load range 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. Then, it is sucked into the compressor 1. In other words, the first refrigerant amount adjustment container 5
The temperature of the suction pipe 8 passing through becomes higher than before the load change. Therefore, the refrigerant in the saturated liquid state inside the first refrigerant amount adjustment container 5 evaporates, so the wetness of the refrigerant inside the first refrigerant amount adjustment container 5 decreases, and the liquid phase ratio of the refrigerant decreases. becomes smaller. As a result, the mass of the refrigerant contained inside the first refrigerant amount adjustment container 5 decreases compared to before the load change. This decreased refrigerant is eventually caused by the refrigerant flowing into the refrigerant circuit from the first connection position 3a in the middle of the expansion device 3 and the refrigerant inside the first refrigerant amount adjustment container 5. The refrigerant is replenished into the refrigerant circuit that had been in use, and the temperature of the suction pipe 8 decreases and becomes balanced with the temperature of the first connection position 3a in the middle of the expansion device 3. Furthermore, since the inside of the second refrigerant amount adjustment container 6 is occupied by superheated steam as before the load change, the mass of the refrigerant accumulated in the second refrigerant amount adjustment container 6 hardly changes.

Next, a case where the load is reduced within the normal load range from a certain load mentioned above (for example, the design thermal load condition) will be described. Under this load condition, 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.
Refrigerant with almost no superheat is sucked into the compressor 1 through the suction pipe 8. In other words, the temperature of the suction pipe 8 passing through the first refrigerant amount regulator 5 becomes lower than before the load is reduced. For this reason, the refrigerant in the saturated vapor state inside the first refrigerant amount adjustment container 5 condenses, so the wetness of the refrigerant inside the first refrigerant amount adjustment container 5 increases, and the liquid phase ratio of the refrigerant increases. growing. As a result, the mass of the refrigerant contained inside the first refrigerant amount adjustment container 5 increases compared to before the load change. This increased refrigerant eventually causes the refrigerant in the refrigerant circuit to reach the first refrigerant amount adjustment container 5.
Since the refrigerant has flowed into the refrigerant circuit, excess refrigerant in the refrigerant circuit has been removed, and the temperature of the suction pipe 8 rises to balance the temperature at the first connection position 3a.
Further, since the inside of the second refrigerant amount adjustment container 6 is occupied by superheated steam as before the load change, the mass of the refrigerant accumulated therein hardly changes.

Next, the operation of the refrigerant amount adjusting device when the load is higher than the normal load (high load) will be explained.

When the load increases in this way, the temperature of the refrigerant passing through the suction pipe 8 becomes even higher than in the case of a normal load, so the inside of the first refrigerant amount adjustment container 5 is almost saturated steam or superheated steam. It will be occupied by Therefore, the mass of the refrigerant contained in the first refrigerant amount adjustment container 5 is reduced compared to the case of normal load, and the reduced amount of refrigerant is replenished into the refrigerant circuit. In addition, the inside of the second refrigerant amount adjustment container 6 is similar to the case of normal load.
Since it is occupied by superheated steam, the mass of refrigerant stored inside it hardly changes.

Next, the operation of the refrigerant amount adjusting device when the load is lower than the normal load range (low load) will be described.

In this way, when the load becomes low, the temperature of the refrigerant passing through the suction pipe 8 becomes even lower than in the case of a normal load, so the inside of the first refrigerant amount adjustment container 5 is almost saturated liquid or supercooled liquid. It will be occupied by liquid. Therefore, the mass of the refrigerant contained in the first refrigerant amount adjustment container 5 increases compared to the case of normal load, and the increased amount of refrigerant is removed from the refrigerant circuit. Moreover, when the temperature of the suction pipe 8 becomes low in this way, the temperature of the suction pipe 8 and the temperature of the second connection position 3b become almost equal, so that the inside of the second refrigerant amount adjustment container 6 is in a gas-liquid two-phase state. becomes saturated. That is, as the load decreases, the wetness of the refrigerant inside the second refrigerant amount adjustment container 6 increases, and the mass of the refrigerant contained therein increases.

In FIG. 7, the horizontal axis represents the magnitude of the load, and the vertical axis represents the mass of the refrigerant accumulated inside the first refrigerant amount adjustment container 5 and the second refrigerant amount adjustment container 6. This shows the change in refrigerant amount in response to fluctuations. As is clear from FIG. 7, in the high load and normal load ranges, the first refrigerant amount adjustment container 5
adjusts the refrigerant amount, and in a low load range, the second refrigerant amount adjustment container 6 adjusts the refrigerant amount.

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.
A is characterized in that it passes through the first refrigerant amount adjustment container 5, and in FIG. It is a point.

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 the explanation will be omitted.

In the examples shown in FIGS. 3, 4, 5, and 8, a connecting pipe 7 connecting the condenser 2 and the throttle device 3, or a branch pipe branching from the connecting pipe 7 7a and the suction pipe 8 are passed through the first refrigerant amount regulating container 5, and the suction pipe 8 is further passed through the second refrigerant amount regulating container 6.The meaning of this penetration is as follows. , the connecting pipe 7 or the branch pipe 7a, and the suction pipe 8, respectively, to exchange heat with the first refrigerant amount adjusting container 5;
and the second refrigerant amount adjustment container 6. Therefore, by bringing the connecting pipe 7 or the branch pipe 7a and the suction pipe 8 into contact with the first refrigerant amount adjustment container 5, or by bringing the suction pipe 8 into contact with the second refrigerant amount adjustment container 6, It may be arranged to exchange heat.

As described above, the refrigerant amount adjusting device of the present invention connects the compressor, the condenser, the throttling device, and the evaporator in an annular manner, and connects the first refrigerant amount adjusting container to the first connecting position in the middle of the throttling device. a second refrigerant amount adjusting container to a second connection position located between the first connection position and the evaporator, and a connection pipe connecting the condenser and the expansion device. Alternatively, a branch pipe branched from the connecting pipe is disposed in the first refrigerant amount adjustment container in a heat exchange manner, and the suction pipe is connected to the first refrigerant amount adjustment container and the second refrigerant amount adjustment container. They are arranged sequentially for heat exchange. 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 connecting pipe connecting a condenser and a throttle device, or
Since a part of the connecting pipe is arranged in the first refrigerant amount adjusting container of the branched pipe for heat exchange,
By selecting the pipe diameter of the connecting pipe or the pipe diameter of the branch pipe, it is possible to arbitrarily select the amount of refrigerant that can be stored in the first refrigerant amount adjustment container under the design heat load condition. Therefore, there is an advantage that the size of the first 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, since the refrigerant amount adjusting device according to the present invention is provided with the second refrigerant amount adjusting container, it can sufficiently perform the refrigerant amount adjusting function, especially in response to load fluctuations at low loads. Therefore, it is possible to completely prevent liquid from returning to the compressor at low loads.

Furthermore, as explained above, since the second refrigerant amount adjustment container performs a wide range of refrigerant amount adjustment functions under low load conditions, the first refrigerant amount adjustment container functions as a refrigerant amount adjustment function under relatively high load conditions. If the pipe diameter of the branch pipe is selected so that the refrigerant amount adjustment function can be achieved in a fairly wide range from high load to low load, the refrigerant amount adjustment device according to the present invention can perform the refrigerant amount adjustment function. As a result, the refrigeration system has the advantage of greatly reducing power consumption during actual use.

[Brief explanation of the drawing]

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 first refrigerant amount adjusting container used in the present invention, FIG. 5 is an enlarged partial cross-sectional view showing the second refrigerant amount adjusting container, FIG. 6 is an explanatory diagram showing the humidity of the refrigerant in the first refrigerant amount adjustment container, FIG. 7 is an explanatory diagram showing the change in the mass of the refrigerant in the first and second refrigerant amount adjustment containers, FIG. 8 is a refrigeration cycle diagram in another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Condenser, 3... Throttling device, 4... Evaporator, 5... First refrigerant amount adjustment container, 6... Second refrigerant amount adjustment container, 7... Connection Pipe, 8... Suction pipe, 3a... First connection position, 3
b...second connection position, 7a...branch pipe.

Claims (1)

[Claims] 1. A compressor, a condenser, a throttling device, and an evaporator are each connected in a ring, and a first refrigerant amount adjustment container is connected to a first connecting position in the middle of the throttling device, and a first connecting position and an evaporator are connected to each other. A second refrigerant amount adjustment container is connected to a second connection position located between the condenser and the expansion device, and a connection pipe connecting the condenser and the expansion device is connected to the first refrigerant amount adjustment container in a heat exchange manner. A refrigerant in a refrigeration system, wherein a suction pipe connecting the compressor and the evaporator is arranged in a first refrigerant amount regulating container and a second refrigerant amount regulating container in order for heat exchange. Amount control device.