JPS5845450A - 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 connection position q in the middle of the expansion device C, or between the expansion device C and the evaporator d, and the compressor a and the evaporator d are connected to each other. A known configuration is known in which a suction pipe f connecting the refrigerant amount adjusting container e is penetrated through the refrigerant amount adjusting 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 expansion device C and the refrigerant amount adjustment container e. Become saturated. However, when the suction pipe amount passes through the refrigerant amount adjustment container e, the temperature of the suction pipe f is usually lower than the temperature at the connection point q between the throttle device C and the refrigerant amount adjustment container e. , a part of the refrigerant inside the refrigerant amount adjustment container e condenses. Therefore, the throttling device C and the refrigerant amount adjustment container e
The humidity of the refrigerant inside the refrigerant amount adjustment container e is greater than the humidity of the refrigerant at the connection position q. That is, when the temperature of the suction pipe f is lower than the temperature of the connection position q, 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 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 e 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. The total amount of heat that enters the refrigerant amount adjustment container e is the sum of ql and 92, and this total amount of heat that enters is represented by a curve q3. Here, the 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 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 one load at point The mass of the refrigerant accumulated inside the refrigerant amount adjustment container e does not change at all. Conversely, if the load becomes much smaller than the load at point X, the inside of the refrigerant amount adjustment container e? The refrigerant is always in a supercooled liquid state, and even if there is a load change, only the degree of supercooling of the refrigerant inside the refrigerant amount adjustment container e changes, and the amount of refrigerant accumulated inside the refrigerant amount adjustment container e changes. There is almost no change in mass. 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 is significantly lower than the load experienced at 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 adjusting the amount of refrigerant within the normal load range in which the refrigeration system is used. Particularly at low loads, there was a disadvantage that liquid returned to the compressor.

Therefore, the present invention solves the above-mentioned conventional drawbacks, and can be used in a refrigerant circuit even in a large load range, a normal load range in which refrigeration equipment is used, and even in a low load range and load fluctuations in all load ranges. 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 depending on the load.

An embodiment of the present invention will be described with reference to FIGS. 3, 4, and 6. As shown in FIG. 3, a compressor 1, a condenser 2.
The throttling device 3 and the evaporator 4 are each connected in a ring.

A first refrigerant amount adjustment container 6 is connected to a first connection position 3a in the middle of the expansion device 3, and a second connection position 3a is connected to the first connection position 3a in the middle of the expansion device 3.
A second refrigerant amount adjustment container 6 is connected to a second connection position 3b located between the refrigerant evaporator 4 and the evaporator 4. Further, the suction pipe 8 connects the compressor 1 and the evaporator 4.

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 the branch pipe 7a is connected to a branch point 7b in the middle of the connecting pipe 7. The other end of a is connected to a confluence point 7C located in the middle of the connecting pipe 7 and closer to the throttle device 3 than the branch point 7b. Furthermore, as shown in FIG. 4, the suction pipe 8 and the branch pipe 7a each penetrate the first refrigerant amount adjustment container 6,
Furthermore, as shown in FIG. 6, the suction pipe 8 also passes through the second 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 is sensitive to load fluctuations.
Although they vary greatly, the temperature at the connection position 3d between the first refrigerant amount adjustment container 6 and the expansion device 3 and the temperature at the connection position 3b between the second refrigerant amount adjustment container 6 and the expansion device 3 are , does not change much. Further, the mass of the refrigerant accumulated in the first refrigerant amount adjustment container 6 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 6 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 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 6 and the second refrigerant amount adjustment container 6 are connected to the same suction pipe 8. However, the humidity of the refrigerant inside the second refrigerant amount adjustment container 6 is always smaller than the humidity of the refrigerant inside the first refrigerant amount adjustment container 5.

It shall be filled with the necessary refrigerant to achieve maximum performance. 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, the temperature of the suction pipe 8 penetrating the first refrigerant amount adjustment container 6 is higher than the temperature of the first connection position 3a where the first refrigerant amount adjustment container 6 and the expansion device 3 are connected. When the load is large, the temperature becomes high, and when the load is normal or low, the temperature becomes low.Furthermore, 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 6 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. Also,
Under normal load, the refrigerant inside the first refrigerant amount adjustment container 6 exhibits a saturation temperature equal to the temperature of the refrigerant at the first connection position 3a; The wetness and the wetness of the refrigerant at the first connection position 3a will be different.

In addition, a suction pipe 8 passing through the second refrigerant amount adjustment container 6
The temperature at the second connection position 3b is higher than the temperature at the second connection position 3b when the load is normal or high, but when the load is low,
The suction pipe 8 has 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 humidity of the refrigerant inside the first refrigerant amount adjustment container 6 and the second refrigerant amount adjustment container 6. In other words, the gas state and liquid state of the refrigerant Since the difference in the specific weight of the states is large, it is important to control the ratio of the liquid phase of the refrigerant inside the first refrigerant amount adjustment container 6 and the second refrigerant amount adjustment container 6.

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 6 is plotted on the vertical axis, and the result under a certain design heat load condition is shown. It shows the ratio of the liquid phase of the refrigerant inside the first refrigerant amount adjustment container 6. for example,
In FIG. 6, if a branch pipe 7a with a pipe diameter indicated by point h is used, under the design heat load conditions, the humidity of the refrigerant inside the first refrigerant amount adjustment container 6 will be i. . In this way, by appropriately selecting the pipe diameter of the branch pipe 7a under a certain design heat load condition, the wetness of the refrigerant inside the first refrigerant amount adjustment container 6 can be appropriately selected.

Next, in the normal load range in which the refrigeration equipment is used,
The operation of the refrigerant amount adjustment device 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 6 (in other words, the mass of the refrigerant contained inside the first refrigerant amount adjustment container 6) is determined by the branch pipe 7a can be selected arbitrarily by appropriately selecting the pipe diameter. Therefore, the refrigerant inside the first refrigerant amount adjustment container 6 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. , compressor 1
will be sucked into. In other words, the temperature of the suction pipe 8 passing through the first refrigerant amount adjustment container 6 becomes higher than before the load change. Therefore, the refrigerant in the saturated liquid state inside the first refrigerant amount adjustment container 6 evaporates, so the wetness of the refrigerant inside the first refrigerant amount adjustment container 6 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 6 decreases compared to before the load change.

This decreased amount of refrigerant is caused by the refrigerant that has flowed into the refrigerant circuit from the first connection position 3a in the middle of the throttling device 3, so the refrigerant is insufficient. 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 circulated in the refrigerant circuit than the amount at which the refrigeration system exhibits its maximum capacity, so refrigerant with almost no superheat is sucked into the compressor 1 through the suction pipe 8. It will be done. In other words, the temperature of the suction pipe 8 passing through the first refrigerant amount adjustment container 6 becomes lower than before the load decreases. For this reason, the saturated vapor state inside the first refrigerant amount adjustment container 6 condenses, so the wetness of the refrigerant inside the first refrigerant amount adjustment container 6 increases, and the proportion of the liquid phase of the refrigerant increases. becomes larger. As a result, the mass of the refrigerant contained inside the first refrigerant amount adjustment container 6 increases compared to before the load change. This increased refrigerant is the refrigerant in the refrigerant circuit that has flowed into the first refrigerant amount adjustment container 6, so the excess refrigerant in the refrigerant circuit has been cooled, and the suction pipe 8 has been cooled down. The temperature increases to balance the temperature at the first connection location 3a.

1. 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 inside it hardly changes.

Next, if the load is even higher than the normal load (quotient load)
The operation of the refrigerant amount adjusting device will be explained.

When the load is high in this way, the temperature of the refrigerant passing through the suction pipe 8 becomes higher than that under normal load, so the refrigerant contained in the inner container 6 of the first refrigerant amount adjustment container 5 The mass of the refrigerant will also be reduced under normal load, and this reduced amount of refrigerant will be replenished into the refrigerant circuit. Further, since the inside of the second refrigerant amount adjustment container 6 is occupied by superheated steam as in the case of normal load, the mass of the refrigerant accumulated therein hardly changes.

Next, if the load is even lower than the normal load range (
The operation of the refrigerant amount adjustment device (low load) will be explained.

In this way, when the load decreases, the temperature of the refrigerant passing through the suction pipe 8 becomes even lower than under normal load, so the inside of the first refrigerant amount adjustment container 6 is almost saturated. liquid or supercooled liquid. For this reason,
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
It will be 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 figure shows the change in the amount of refrigerant with respect to the change in the amount of refrigerant.

As is clear from FIG. 7, in the high load 9 normal load range, the first refrigerant amount adjustment container 6 mainly adjusts the refrigerant amount, and in the low load range, the second refrigerant amount adjustment container 6 adjusts the refrigerant amount. Adjust the 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. In FIG. 8, the connecting pipe 7 is not branched and is passed through the first refrigerant amount adjusting container 6.

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 addition, in the example shown in FIG. 3, FIG. 4, FIG. 6, and FIG. 8, the connecting pipe 7 connecting the condenser 2 and the throttle device 3
Alternatively, the branch pipe 7a branched from the connecting pipe 7 and the suction pipe 8 are passed through the first refrigerant amount adjustment container 6, and further,
The suction pipe 8 is passed through the second refrigerant amount adjustment container 6, but the meaning of this penetration is that the connection pipe 7 or the branch pipe 7a and the suction pipe 8 are respectively adjusted to the first refrigerant amount. The purpose is to exchange heat with the regulating container 6 and further to exchange heat with the suction pipe 8 and the second refrigerant amount regulating container 6. Therefore,
Heat exchange is performed 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 6, or by bringing the suction pipe 8 into contact with the second refrigerant amount adjustment container 6. It may be arranged so as to

As described above, the refrigerant amount adjusting device of the present invention includes a compressor, a condenser, a throttling device, and an evaporator connected in an annular manner,
A first refrigerant amount adjustment container is connected to a first connection position in the middle of the expansion device, and a second refrigerant amount adjustment container is connected to a second connection position located between the first connection position and the evaporator. A connecting pipe connected to the connecting position and connecting the condenser and the throttling device, or a branch pipe branched from the connecting pipe is disposed in the first refrigerant amount adjusting container in a heat exchange manner, and further, the suction The pipes are sequentially arranged in a first refrigerant amount regulating container and a second refrigerant amount regulating container 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 throttling device, or a branch pipe that is a branched part of the connecting pipe, is connected to the first refrigerant amount adjusting container for heat exchange. By straddling the pipe diameter of the connecting pipe and appropriately selecting the pipe diameter of the branch pipe, the amount of refrigerant that can be accumulated in the first refrigerant amount adjustment container under the design heat load conditions can be adjusted. You can choose as you like. 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 high and low load conditions 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 loads, the refrigerant amount adjustment function of the first refrigerant amount adjustment container performs 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, the refrigerant amount adjustment device according to the present invention can perform the refrigerant amount adjustment function in a fairly wide range from high load to low load.

As a result, the refrigeration system has the advantage of greatly reducing power consumption during actual use.

[Brief explanation of the drawing]

Part 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 refrigerant amount according to an embodiment of the present invention. A diagram of a refrigeration cycle equipped with an adjustment device; FIG. 4 is an enlarged partial cross-sectional view showing the first refrigerant amount adjusting container used in the present invention; FIG. 6 is a partial cross-sectional view showing the second refrigerant amount adjusting container. An enlarged view, FIG. 6 is an explanatory view showing the wetness of the refrigerant in the second refrigerant amount adjustment container, and FIG. 7 is an explanatory view showing changes in the mass of the refrigerant in the second and second refrigerant amount adjustment containers. 8 are refrigeration cycle diagrams in other embodiments of the present invention. 1... Compressor, 2... Condenser, 3...
- Squeezing device, 4 - Evaporator, 6 - First refrigerant amount adjustment container, 6... Second refrigerant amount adjustment container,
7... Connection pipe, 8... Suction pipe, 3a...
-First connection position, 3b...Second connection position, 7a...Branch pipe. Name of agent Patent attorney Toshio Nakao and one other person Construction drawings Figure 2 Figure 3 Figure 6 JIK Figure 7

Claims (1)

[Claims] A compressor, a condenser, a throttling device, and an evaporator are each connected in a ring, and a first refrigerant amount adjusting container is connected to a first connecting position in the middle of the throttling device, and a first connecting position and the evaporator are connected to each other. A second refrigerant amount adjustment container is connected to a second connection position located between the connecting pipe and the connecting pipe connecting the condenser and the expansion device, or a branch pipe branched from the connecting pipe. A suction pipe connecting the compressor and the evaporator is arranged in a heat exchange manner in a first refrigerant amount adjustment container and a second refrigerant amount adjustment container in order. A refrigerant amount adjustment device in a refrigeration system installed in a refrigeration system.