JP3351001B2 - Liquid-filled evaporator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled evaporator mainly used for a screw-type refrigeration system and the like.
A heat exchange tube connecting a cold water inlet pipe and a cold water outlet pipe, a refrigerant liquid inlet provided at a lower part of the body, a refrigerant gas outlet provided at an upper part, and a refrigerant liquid introduced into the body through the heat exchange tube. The present invention relates to a liquid-filled evaporator that evaporates a refrigerant liquid by exchanging heat with flowing cold water.

[0002]

2. Description of the Related Art Generally, in a screw-type refrigeration system using a liquid-filled evaporator, oil in a refrigerant circulating in a refrigeration cycle tends to stay in the liquid-filled evaporator, and the oil on the compressor side is easily removed. It is necessary to positively return the oil remaining in the liquid-filled evaporator to the compressor side, since there is a possibility that insufficient lubrication may occur due to insufficient oil.

Therefore, conventionally, in order to actively return the oil remaining in the liquid-filled evaporator to the compressor side, it is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-28962 and shown in FIG. As described above, in a refrigerating apparatus in which a screw compressor A, a condenser B, an expansion valve C, and a liquid-filled evaporator D are connected by a refrigerant pipe, the refrigerant is used by using a refrigerant heater F equipped with an electric heater E. A first pipe G communicating with the liquid area of the evaporator D is connected to the upper side of the heater F, and the refrigerant heater F
Is connected to one end of a second pipe I having a pump H on the way, the other end of the second pipe I is connected to the compressor A side, and the upper side of the refrigerant heater F Is connected to the downstream side of the evaporator D via a third pipe J.

[0004] Then, from the evaporator D to the first pipe G
A refrigerant liquid containing oil is introduced into the refrigerant heater F through the heater, and the refrigerant liquid is heated by a heater E in the refrigerant heater F to evaporate and concentrate the oil. The refrigerant liquid thus collected is positively returned from the second pipe I to the compressor A via the pump H. The refrigerant gas evaporated by the heater E in the refrigerant heater F is supplied to the compressor A from the downstream side along with the refrigerant gas passing through the evaporator D via the third pipe J.

[0005]

However, when the oil in the liquid-filled evaporator D is returned to the compressor A by using the refrigerant heater F as described above, the refrigerant heater F must be provided separately, and a power source and wiring for heating the heater E provided in the refrigerant heater F are also separately required. The required equipment such as the refrigerant heater F and the heater E is required. In addition to the increase, there is a problem that the entire piping configuration is complicated.

Conventionally, for example, Japanese Patent Publication No. 1-206
As shown in Japanese Patent Publication No. 97, the refrigerant liquid mixed with oil is taken out of the liquid region of the liquid-filled evaporator to the outside, and passed through a heat exchanger using a high-temperature refrigerant liquid that has passed through the condenser, In the heat exchanger, the refrigerant liquid taken out of the evaporator is heated and evaporated with a high-temperature refrigerant from the condenser to the evaporator, and an ejector or the like is used on the low-pressure side of the compressor as oil-containing refrigerant gas. However, in such a case, as in the case described above, the number of necessary devices increases, and the entire piping configuration becomes complicated.

An object of the present invention is to provide a liquid-filled evaporator that can return oil in a liquid-filled evaporator to the compressor side while reducing the number of devices and simplifying the piping configuration. It is in.

[0008]

In order to achieve the above-mentioned object, the present invention provides a horizontally elongated body 5 extending substantially horizontally, a cold water inlet pipe 61 and a cold water outlet pipe 6 provided at a lower portion of the body 5.
A heat exchange tube 6 for connecting the refrigerant gas 2 to the main body 5, a refrigerant liquid inlet 7 at the lower part of the body 5, and a refrigerant gas outlet 9 at the upper part.
The refrigerant liquid introduced into the body 5 is supplied to the heat exchange tube 6.
In a liquid-filled evaporator that evaporates the refrigerant liquid by exchanging heat with cold water flowing through the inside, the body 5
A partition body 11 extending in the length direction is provided on one side of the inside, and a liquid region in the body 5 is divided into a main evaporator 51 and an auxiliary evaporator 52, and the refrigerant liquid inlet 7 is provided in the main evaporator 51. So that the refrigerant liquid is introduced from the main evaporator 51 to the auxiliary evaporator 52, while the heat exchange tube 6 arranged in the auxiliary evaporator 52 is connected to the cold water inlet pipe 61 to concentrate the oil. The oil return pipe 12 was connected to the liquid area of the auxiliary evaporator 52.

The auxiliary evaporator 52 in the body 5
A straightening plate 13 extending obliquely upward from the liquid region to the gas region above the main evaporating portion 51 is provided.
The refrigerant gas outlet 9 is provided on the upper side of the refrigerant gas outlet pipe 1.
0, and an oil that opens the liquid region of the auxiliary evaporator 52 to the upper surface side of the rectifier plate 13 at the lower end of the rectifier plate 13 that is immersed in the liquid region of the auxiliary evaporator 52 at the inclined lower end side. A return passage 13b may be provided.

Further, the rectifying plate 13 is provided which extends obliquely upward from above the auxiliary evaporator 52 to above the main evaporator 51 in the body 5.
The refrigerant gas outlet 9 is provided on the upper side of the second side, the refrigerant gas outlet pipe 10 is connected, and the oil return pipe 14 is connected to the liquid region of the auxiliary evaporator 52. The refrigerant gas outlet pipe 10
May be opened toward the downstream side of the.

It is preferable that the auxiliary evaporator 52 is provided with a liquid level detector 15 for detecting the liquid level of the auxiliary evaporator 52 and controlling the liquid level controller 17.

[0012]

In the main evaporator 51 and the auxiliary evaporator 52, the refrigerant liquid is evaporated by exchanging heat with cold water passing through the heat exchange tube 6 separately. Since the heat exchange tube 6 is connected to the chilled water inlet pipe 61, the temperature of the chilled water is circulated through a cooling unit or the like and the temperature of the chilled water becomes high. The refrigerant liquid of the auxiliary evaporator 52 is actively heated by the high-temperature cold water, so that the refrigerant liquid evaporates actively.
Since the refrigerant liquid flowing from the refrigerant liquid inlet 7 is introduced from the main evaporator 51 to the auxiliary evaporator 52, the refrigerant liquid in the auxiliary evaporator 52 is converted into an oil-rich oil in which oil is concentrated. It can be formed as a refrigerant liquid.

As described above, since the oil can be concentrated in the auxiliary evaporator 52, it is not necessary to separately provide a refrigerant heater or a heat exchanger having a heater as in the related art. The piping configuration can be simplified because only the oil return pipe 12 is provided, so that equipment for concentrating the oil can be eliminated, and the piping configuration can be simplified while maintaining the inside of the liquid-filled evaporator. Oil can be effectively returned to the compressor.

An auxiliary evaporator 52 in the body 5
A straightening plate 13 extending obliquely upward from the liquid region to the gas region above the main evaporating portion 51 is provided.
The refrigerant gas outlet 9 is provided on the upper side of the refrigerant gas outlet pipe 1.
0, and an oil that opens the liquid region of the auxiliary evaporator 52 to the upper surface side of the rectifier plate 13 at the lower end of the rectifier plate 13 that is immersed in the liquid region of the auxiliary evaporator 52 at the inclined lower end side. When the return passage 13b is provided, in the main evaporator 51 and the auxiliary evaporator 52, the refrigerant gas evaporated by the contact with the heat exchange tube 6 passes through the rectifying plate 13 and is rectified. The gas is sent to the compressor 1 through the gas outlet pipe 10 satisfactorily, and due to the rectifying action of the rectifying plate 13, during operation, the upper pressure on the rectifying plate 13, that is, the secondary pressure is reduced by the main evaporation. Utilizing the fact that the pressure is lower than the primary pressure below the rectifying plate 13 constituting the part 51 and the auxiliary evaporating part 52, that is, the upper surface side pressure of the rectifying plate 13 is the pressure of the auxiliary evaporating part 52, Primary side of current plate 13 By utilizing the fact that the low pressure to force the refrigerant liquid oil is concentrated in the auxiliary evaporator 52 by this pressure difference, the flow regulating plate from the oil return passage 13b 1
3 and can be returned to the compressor together with the refrigerant gas flowing out of the refrigerant gas outlet pipe 10 through the flow regulating plate 13, and therefore, as in the conventional case, the refrigerant heater or heat exchange The oil can be returned to the compressor without the need to separately provide a heater or the like, or to provide a pump or ejector for sending the refrigerant liquid concentrated with the refrigerant heater or the like to the compressor. is there. Moreover, in this case, since the refrigerant can be returned from the current plate 13 to the compressor via the refrigerant gas outlet pipe 10, there is no need to separately provide an oil return pipe, and the piping configuration can be further simplified.

Further, an auxiliary evaporator 5 in the body 5
The rectifying plate 13 extending obliquely above the main evaporator 51 from above the rectifying plate 2, and the refrigerant gas outlet 9 is provided above the rectifying plate 13 on the side of the auxiliary evaporator 52, and the refrigerant gas outlet pipe 1 is provided.
0, and an oil return pipe 14 is connected to the liquid region of the auxiliary evaporator 52. The oil return pipe 14 is inserted into the refrigerant gas outlet pipe 10, and the oil gas return pipe 14 is located downstream of the refrigerant gas outlet pipe 10. , The oil-rich refrigerant liquid from the auxiliary evaporator 52 is ejected from the auxiliary evaporator 52 by the ejector action.
3 and can be returned to the compressor together with the refrigerant gas flowing out of the refrigerant gas outlet pipe 10. Therefore,
In this case as well, it is only necessary to provide the oil return pipe 14 connecting the auxiliary evaporator 52 and the refrigerant gas outlet pipe 10, so that the piping configuration can be simplified.

In addition, when the operation is stopped, even if the liquid level of the refrigerant liquid in the body 5 may be higher than the upper wall portion of the partition 11, the refrigerant liquid enters and accumulates on the rectifying plate 13. Therefore, when the operation is resumed, the current plate 13
It is also possible to avoid the danger of a so-called liquid back in which a large amount of the refrigerant liquid collected from the refrigerant gas outlet pipe 10 returns to the compressor 1 side.

The auxiliary evaporator 52 is provided with a liquid level detector 15 for detecting the liquid level of the auxiliary evaporator 52 and controlling the liquid level controller 17 so that the liquid level is detected. The level of the auxiliary evaporator 52 is detected by the heater 15 and the opening of the flow regulating valve 16 can be controlled by the output from the controller 17 based on the detection result. From the refrigerant liquid inlet pipe 7 to the main evaporator 5 of the body 5
The amount of the refrigerant introduced into 1 can be adjusted and controlled so as to be always lower than the upper height of the partition plate 11,
Therefore, it is possible to prevent a decrease in oil concentration due to the introduction of a large amount of refrigerant liquid from the main evaporator 51 to the auxiliary evaporator 52.
The refrigerant liquid having a high oil concentration can be returned to the compressor.

[0018]

FIG. 3 shows a piping system of a screw refrigerating apparatus using a liquid-filled evaporator.
Condenser 2 and expansion valve 3 and liquid-filled evaporator 4
Are connected via refrigerant pipes, and these devices form a refrigeration cycle.

As shown in FIG. 1 and FIG. 2, the liquid-filled evaporator 4 has a heat exchange tube 6 meandering in the longitudinal direction at the lower portion inside the horizontally long body 5 extending substantially horizontally. In addition, a refrigerant liquid inlet 7 is provided at a lower side of the body 5, and a refrigerant liquid inlet pipe 8 extending from the expansion valve 3 side is connected to the refrigerant liquid inlet 7, while a refrigerant gas is provided at an upper side of the body 5. An outlet 9 is provided, and the compressor 1 is connected to the refrigerant gas outlet 9.
The refrigerant gas outlet pipe 10 reaching the side is connected. Further, a cold water inlet pipe 61 and a cold water outlet pipe 62 are connected to the cold water inlet and outlet sides of the heat exchange tube 6, respectively. In the embodiment shown in FIGS. The cold water inlet pipe 61 is connected to the heat exchange tube 6 disposed on one side in the direction to take in cold water, while the body 5
The cold water outlet pipe 62 is connected to the tube 6 disposed on the other side in the radial direction of the above to take out the cooling water.

That is, the condenser 2 is inserted from the refrigerant liquid inlet 7 through the refrigerant liquid inlet pipe 8 to the lower inside of the body 5.
, A refrigerant liquid containing oil is introduced through the expansion valve 3, and the refrigerant liquid exchanges heat with the chilled water sent from the chilled water inlet pipe 61 into the heat exchange tube 6. While being cooled and taken out from the cold water outlet pipe 62 and sent to a cooling unit or the like, the refrigerant liquid evaporates by heat exchange with the heat exchange tube 6, and the evaporated refrigerant gas is supplied to the upper part of the body 5. A refrigerant gas outlet 9 provided on the side is returned to the compressor 1 via a refrigerant side outlet pipe 10.

The partition 11 extending in the longitudinal direction of the body 5 in the liquid area at one side in the radial direction in the body 5.
The partition 11 separates the liquid region in the body 5 into a main evaporator 51 and an auxiliary evaporator 52, and the main evaporator 51 is provided with the refrigerant liquid inlet 7, Partition body 1
1, a communication portion 11a for communicating the main evaporator 51 and the auxiliary evaporator 52 is formed, and the refrigerant liquid supplied to the main evaporator 51 from the refrigerant liquid inlet 7 through the communication portion 11a. Is introduced to the auxiliary evaporator 52 side. The auxiliary evaporator 52 defined by the partition 11 is connected to the cold water inlet side of the heat exchange tube 6 to which the cold water inlet pipe 61 is connected to form an oil concentrating unit. 5 opens to the liquid area of the auxiliary evaporator 52,
An oil return pipe 12 reaching the compressor 1 is connected.

That is, the heat exchange tube 6 provided in the auxiliary evaporator 52 is provided with the cold water inlet pipe 6 so that the high temperature cold water returned by circulating through a cooling unit or the like can be used.
1 and actively heats the refrigerant liquid introduced into the auxiliary evaporator 52 from the main evaporator 51 with high-temperature cold water flowing on the cold water inlet side of the heat exchange tube 6 to actively evaporate. Then, the refrigerant liquid in the auxiliary evaporator 52 is turned into an oil-rich refrigerant liquid in which oil is concentrated, and the oil-rich refrigerant liquid in which the oil is concentrated is returned from the oil return pipe 12 to the compressor 1. To do so.

A communication portion 11 provided on the partition 11
a is formed by providing a notch in the upper part of the partition body 11, and the oil return pipe 12 is provided with the auxiliary evaporator 5
2 is connected to the side of the body 5 so as to open to a liquid region near the connection between the heat exchange tube 6 and the cold water inlet pipe 61 in the longitudinal direction.
An oil-rich refrigerant liquid can be taken out through the oil return pipe 12 from the cold water inlet side of the auxiliary evaporator 52 where the refrigerant liquid is heat-exchanged by the hottest cold water introduced from the cold water inlet pipe 61. The refrigerant liquid having the highest oil concentration can be returned to the compressor 1 via the oil return pipe 12.

Next, the operation of the above configuration will be described. During operation of the liquid-filled evaporator 4, first, oil-containing refrigerant liquid is introduced from the refrigerant liquid inlet pipe 8 through the refrigerant liquid inlet 7 into the main evaporator 51 of the body 5, and this refrigerant liquid and the The cold water in the heat exchange tube 6 is heat-exchanged to cool the cold water. Cooling water is taken out from the cold water outlet pipe 62 connected to the heat exchange tube 6 and sent to a cooling unit or the like, while the coolant liquid Is evaporated by heat exchange with the heat exchange tube 6 to become a refrigerant gas, and the refrigerant gas is supplied from the refrigerant gas outlet 9 provided on the upper side of the body 5 through the refrigerant gas outlet pipe 10 to the compressor 1. Return to

The refrigerant liquid is introduced into the main evaporator 51 defined by the partition 11, and the refrigerant liquid whose oil concentration has been increased by the heat exchange in the main evaporator 51 is removed by the partition 11.
The refrigerant liquid is introduced into the auxiliary evaporator 52 from the communication part 11a, and the refrigerant liquid exchanges heat with the cold water passing through the heat exchange tube 6 provided in the auxiliary evaporator 52.
In addition, the cold water flowing in the heat exchange tube 6 circulates through a cooling unit or the like and becomes high temperature, and the cold water inlet pipe 6
Since the high-temperature cold water returns to 1, in the auxiliary evaporator 52, the refrigerant liquid is actively heated by the high-temperature cold water and evaporates to a refrigerant gas, and the refrigerant liquid in the auxiliary evaporator 52 is subjected to the main evaporation. This makes it possible to form an oil-rich refrigerant liquid in which the oil is concentrated and higher in oil concentration than the refrigerant liquid in the section 51. Therefore, the refrigerant liquid having a high oil concentration can be returned from the oil return pipe 12 connected to the auxiliary evaporator 52 to the compressor 1 side.

Therefore, in the above-mentioned full-liquid evaporator 4, since the oil can be concentrated in the auxiliary evaporator 52, the oil can be concentrated in the full-liquid evaporator 4, and the conventional liquid evaporator 4 can be concentrated. Thus, it is not necessary to separately provide a refrigerant heater, a heat exchanger, and the like, and the piping configuration is the same as that of the oil return pipe 1.
2, the number of devices can be reduced, and the piping structure can be simplified, and the oil in the liquid-filled evaporator can be reliably returned to the compressor 1 side. It is.

According to the present invention, as shown in FIG. 4 as a second embodiment, the partition 5 extends inside the body 5 in the longitudinal direction of the body 5 and is defined by the partition 11. A long straightening plate 13 extending obliquely upward from the liquid area of the auxiliary evaporating section 52 to the gas area above the main evaporating section 51 is provided, and the inside of the body 5 is divided into an evaporating chamber 53 and a rectifying chamber 54. The refrigerant gas outlet 9 is opened in the rectification chamber 54 to connect the refrigerant gas outlet pipe 10 and the rectification plate 13
As shown in FIG. 5, a plurality of rectifying passages 13a in the shape of an arc groove for connecting the gas area of the evaporation chamber 53 to the refrigerant gas outlet pipe 10 through the rectifying chamber 54 at the upper end side of the slope. And the lower end side of the rectifying plate 13 is immersed in the liquid area of the auxiliary evaporator 52, and the liquid area of the auxiliary evaporator 52 is placed on the upper surface side of the rectifier plate 13. A round hole-shaped oil return passage 13b that opens may be provided. In the above configuration, the refrigerant gas evaporated by the contact with the heat exchange tube 6 in the main evaporator 51 and the auxiliary evaporator 52 is supplied to the rectifying plate 1.
After flowing into the rectification chamber 54 from the rectification passage 13a of the compressor 1 and rectifying it, the compressor 1 passes through the refrigerant gas outlet pipe 10.
Side, and at the time of operation of the refrigeration system, utilizing the fact that the pressure of the rectifying chamber 54 becomes lower than that of the evaporation chamber 53 by the rectifying action of the rectifying plate 13, that is, the rectifying plate is used. Utilizing the fact that the pressure of the rectification chamber 54 on the upper surface side of the thirteen is lower than that of the auxiliary evaporator 52, the refrigerant liquid with a high oil concentration concentrated in the auxiliary evaporator 52 is returned to the oil by differential pressure. It can be sucked up from the passage 13b to the upper surface side of the rectifying plate 13 and returned to the compressor 1 together with the refrigerant gas flowing out to the refrigerant gas outlet pipe 10 through the rectifying passage 13a of the rectifying plate 13. . Therefore, unlike the related art, it is not necessary to separately provide a refrigerant heater or a heat exchanger, etc., and even without separately providing a pump or an ejector for returning the refrigerant liquid having a high oil concentration to the compressor, It can be effectively returned to the compressor 1, and according to the second embodiment, it is not necessary to provide the oil return pipe 12 of the first embodiment shown in FIG. The configuration can be simplified.

The oil return passage 13b provided in the flow straightening plate 13 is preferably formed on the cold water inlet pipe connection side of the auxiliary evaporator 52 where the refrigerant liquid having the highest oil concentration is obtained. Accordingly, the refrigerant liquid having the highest oil concentration can be sent to the compressor 1 side.

Further, in the present invention, as shown in the third embodiment of FIG. 6, the body 5 extends in the longitudinal direction of the body 5 and is defined by the partition 11. The long straightening plate 13 extending obliquely upward from the upper side of the auxiliary evaporation portion 52 to the top of the main evaporation portion 51 is provided to partition the body 5 into an evaporation chamber 53 and a straightening chamber 54, and A plurality of rectification passages 13a are formed on the upper end side of the inclination of 13,
Further, the refrigerant gas outlet 9 is opened in the rectification chamber 54, the refrigerant gas outlet pipe 10 is connected, and the refrigerant gas outlet pipe 1 is opened in the liquid region of the auxiliary evaporator 52.
An oil return pipe 14 having a diameter smaller than 0 is connected to the body 5, the oil return pipe 14 is raised upward from an intermediate portion, and then enters the refrigerant gas outlet pipe 10. The oil return pipe 14 may be bent substantially parallel to the refrigerant gas outlet pipe 10 so as to open the distal end opening of the oil return pipe 14 toward the downstream side of the refrigerant gas outlet pipe 10.

In the above configuration, the refrigerant liquid having a high oil concentration in the auxiliary evaporator 52 is discharged from the oil return pipe 14 to the compressor 1 through the refrigerant gas outlet pipe 10 by an ejector action. Can be returned to. Therefore, in this case also, it is only necessary to provide the oil return pipe 14 that connects the auxiliary evaporator 52 and the refrigerant gas outlet 9 near the connection point of the refrigerant gas outlet 9. The configuration can be simplified.

Further, even when the liquid level of the refrigerant liquid in the body 5 may be higher than the upper wall portion of the partition 11 when the operation is stopped, as shown in the embodiment of FIG. Since the refrigerant liquid 52 does not enter and accumulate on the rectifying plate 13, the rectifying plate 13
It is also possible to avoid the danger of a so-called liquid back in which a large amount of the refrigerant liquid collected from the refrigerant gas outlet pipe 10 returns to the compressor 1.

As shown in FIG. 7, a liquid level detecting device for detecting the liquid level of the auxiliary evaporator 52 is provided on the side of the body 5, as shown in FIG. A flow control valve 16 is interposed in a pipe connecting the condenser 2 and the evaporator 4, and the liquid level detector 15 is provided.
The amount of refrigerant introduced from the refrigerant liquid inlet pipe 7 into the main evaporator 51 of the body 5 is always lower than the upper height of the partition plate 11, and the auxiliary evaporator 52 The flow rate to the evaporator 4 is controlled by controlling the degree of opening of the flow control valve 16 so as to be an amount that can be introduced when the introduction of the liquid refrigerant from the main evaporator 51 to the evaporator 4 is stopped. A liquid level controller 17 for controlling the liquid level in the vessel 4 may be provided.

In the above-described configuration, the liquid level detector 15 detects the liquid level of the auxiliary evaporator 52, and the output from the controller 17 based on the result of the detection detects the liquid level of the flow regulating valve 16. Since opening degree control can be performed,
The amount of the refrigerant introduced from the refrigerant liquid inlet pipe 7 into the main evaporator 51 of the body 5 is adjusted and controlled so as to be always lower than the upper height of the partition plate 11. A decrease in the oil concentration due to the introduction of a large amount of the refrigerant liquid from the evaporator 51 to the auxiliary evaporator 52 can be prevented, that is, it is possible to prevent the refrigerant liquid having a low oil concentration from returning to the compressor 1, The refrigerant liquid having a high oil concentration can be returned to the compressor 1.

[0034]

As described above, in the liquid-filled evaporator of the present invention, the partition 11 extending in the longitudinal direction is provided on one side of the body 5 so that the liquid area in the body 5 is mainly evaporated. Part 51
And an auxiliary evaporator 52, and the main evaporator 5
1 is provided with the refrigerant liquid inlet 7 so that the refrigerant liquid is introduced from the main evaporator 51 to the auxiliary evaporator 52, while the heat exchange tube 6 provided in the auxiliary evaporator 52 is connected to the cold water inlet pipe. 61 to form an oil concentrating section, and the oil return pipe 12 is connected to the liquid area of the auxiliary evaporating section 52, so that the refrigerant liquid of the auxiliary evaporating section 52 is circulated through a cooling unit or the like to become high temperature, Heat exchange is performed by the high-temperature return cold water taken in from the cold-water inlet pipe 61. Therefore, the refrigerant liquid of the auxiliary evaporator 52 is actively heated by the high-temperature cold water, and the refrigerant liquid evaporates actively. That is, the refrigerant liquid flowing from the refrigerant liquid inlet 7 is once introduced into the main evaporator 51 and is then introduced into the auxiliary evaporator 52 from the main evaporator 51. , The auxiliary evaporator 2 definitive refrigerant liquid is the oil can be made with the refrigerant liquid of concentrated oil-rich.

As described above, the oil can be concentrated in the auxiliary evaporator 52, so that the oil can be concentrated in the liquid-filled evaporator. It is not necessary to separately provide a heater, a heat exchanger, or the like, and the piping configuration can be simplified simply by providing the oil return pipe 12, so that it is possible to eliminate equipment for concentrating oil, In addition, the oil in the liquid-filled evaporator can be effectively returned to the compressor while the piping configuration can be simplified.

The auxiliary evaporator 52 in the body 5
A straightening plate 13 extending obliquely upward from the liquid region to the gas region above the main evaporating portion 51 is provided.
The refrigerant gas outlet 9 is provided on the upper side of the refrigerant gas outlet pipe 1.
0, and an oil that opens the liquid region of the auxiliary evaporator 52 to the upper surface side of the rectifier plate 13 at the lower end of the rectifier plate 13 that is immersed in the liquid region of the auxiliary evaporator 52 at the inclined lower end side. By providing the return passage 13b, the main evaporator 51
And in the auxiliary evaporator 52, the refrigerant gas evaporated by the contact with the heat exchange tube 6 is rectified by passing through the rectifying plate 13 and then to the compressor 1 side via the refrigerant gas outlet pipe 10. Due to the rectifying action of the rectifying plate 13, the pressure on the upper surface side of the rectifying plate 13, that is, the secondary pressure, causes the main evaporating section 51 and the auxiliary evaporating section 52 to be moved during operation. Utilizing the pressure on the lower surface side, that is, the pressure lower than the primary side pressure, the refrigerant liquid in which the oil is concentrated in the auxiliary evaporator 52 by the differential pressure is transferred from the oil return passage 13b to the rectifying plate. 13 and can be returned to the compressor together with the refrigerant gas flowing out of the refrigerant gas outlet pipe 10 through the flow regulating plate 13, and therefore, as in the conventional case, a refrigerant heater or heat Exchanger, etc. Separately or provided, also, it is the oil in these refrigerant heater and the like can be returned without the need the compressor provided specially well pump or ejector or the like for sending to the compressor the refrigerant liquid which has been concentrated. Moreover, in this case, since it is possible to return to the compressor from the straightening plate 13 via the refrigerant gas outlet pipe 10, there is no need to provide an oil return pipe, and it is possible to eliminate an extra pipe.

Further, the auxiliary evaporator 5 in the body 5
The straightening plate 13 extending obliquely upward from above the main evaporator 51 from above the second evaporator 2 is provided.
The refrigerant gas outlet 9 is provided on the upper side, the refrigerant gas outlet pipe 10 is connected, and the oil return pipe 14 is connected to the liquid region of the auxiliary evaporator 52, and the oil return pipe 14 is connected to the refrigerant gas outlet. The refrigerant liquid in which the oil is concentrated in the auxiliary evaporator 52 is ejected by the ejector action by ejecting the refrigerant gas into the pipe 10 and opening toward the downstream side of the refrigerant gas outlet pipe 10. It can be returned to the compressor together with the refrigerant gas flowing out of the refrigerant gas outlet pipe 10. Therefore, also in this case, it is only necessary to provide the oil return pipe 14 that connects the auxiliary evaporator 52 and the refrigerant gas outlet pipe 10, so that the piping configuration can be simplified.

In addition, when the operation is stopped, even if the liquid level of the refrigerant liquid in the body 5 may be higher than the upper wall portion of the partition body 11, the refrigerant liquid may enter and accumulate on the rectifying plate 13. Therefore, when the operation is resumed, the current plate 13
It is also possible to avoid the danger of a so-called liquid back in which a large amount of the refrigerant liquid collected from the refrigerant gas outlet pipe 10 returns to the compressor 1.

The auxiliary evaporator 52 is provided with a liquid level detector 15 for detecting the liquid level of the auxiliary evaporator 52 and controlling the liquid level controller 17 so that the liquid level is detected. The level of the liquid level of the auxiliary evaporator 52 is detected by the heater 15, and the opening degree of the flow regulating valve 16 can be controlled by the output from the controller 17 based on the detection result. From the refrigerant liquid inlet pipe 7 to the main evaporator 51 of the body 5
The amount of refrigerant introduced into the partition plate 11 can be adjusted and controlled so as to be always lower than the upper height of the partition plate 11, so that a large amount of refrigerant liquid is introduced from the main evaporator 51 to the auxiliary evaporator 52. Therefore, it is possible to prevent a decrease in the oil concentration due to this, and to return the refrigerant liquid having a high oil concentration to the compressor.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a liquid-filled evaporator according to the present invention.

FIG. 2 is a perspective view showing the overall structure of a liquid-filled evaporator of the first embodiment.

FIG. 3 is a piping diagram of a refrigeration system using the liquid-filled evaporator of the first embodiment.

FIG. 4 is a longitudinal sectional view showing a second embodiment of the liquid-filled evaporator of the present invention.

FIG. 5 is a partially omitted front view of a current plate used in the second embodiment.

FIG. 6 is a vertical sectional view showing a third embodiment of the liquid-filled evaporator of the present invention.

FIG. 7 is a piping diagram showing an embodiment in which a liquid level detector is provided in the liquid-filled evaporator of the present invention.

FIG. 8 is a vertical sectional view showing a conventional liquid-filled evaporator.

[Explanation of symbols]

 Reference Signs List 5 Body 51 Evaporator 52 Auxiliary evaporator 6 Heat exchange tube 61 Cold water inlet pipe 62 Cold water outlet pipe 7 Refrigerant liquid inlet 9 Refrigerant gas outlet 10 Refrigerant gas outlet pipe 11 Partition body 12, 14 Oil return pipe 13 Straightening plate 13b Oil return passage 15 Liquid level detector 17 Liquid level height controller

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 1/00 F25B 1/053 F25B 39/02 F25B 43/02

Claims (4)

(57) [Claims] An elongated body (5) extending substantially horizontally, and a heat exchange tube (6) disposed at a lower portion of the body (5) and connecting a cold water inlet pipe (61) and a cold water outlet pipe (62). A refrigerant liquid inlet (7) at the lower part of the body (5) and a refrigerant gas outlet (9) at the upper part, and the liquid refrigerant introduced into the body (5) is supplied to the heat exchange tube (6). A liquid-filled evaporator for evaporating a liquid refrigerant by exchanging heat with cold water flowing through the inside, wherein a partition (11) extending in a length direction is provided on one side of the body (5); The liquid region in the body (5) is divided into a main evaporator (51) and an auxiliary evaporator (52), and the main evaporator (51) is provided with the refrigerant liquid inlet (7). The refrigerant liquid is introduced from (51) to the auxiliary evaporator (52), while the auxiliary evaporator (52) is introduced. The heat exchange tube (6) to be provided is connected to the cold water inlet pipe (61) to form an oil concentrating section, and an oil return pipe (12) is connected to the liquid area of the auxiliary evaporator (52). A liquid-filled evaporator characterized in that: 2. A rectifying plate (13) extending obliquely upward from a liquid region of the auxiliary evaporator (52) in the body (5) to a gas region above the main evaporator (51). A refrigerant gas outlet (9) is provided above the auxiliary evaporator (52),
The refrigerant gas outlet pipe (10) is connected, and the lower end of the current plate (13) is immersed in the liquid area of the auxiliary evaporator (52) at the inclined lower end side. Oil return passage (13) opening on the upper surface side of the current plate (13).
2. A liquid-filled evaporator according to claim 1, wherein b) is provided. 3. A rectifying plate (13) extending obliquely upward from above the auxiliary evaporator (52) to above the main evaporator (51) in the body (5), and the auxiliary evaporator of the rectifier (13) is provided. A refrigerant gas outlet (9) is provided above the (52) side, a refrigerant gas outlet pipe (10) is connected, and an oil return pipe (14) is connected to a liquid region of the auxiliary evaporator (52). The liquid-filled evaporator according to claim 1, wherein an oil return pipe (14) protrudes into the refrigerant gas outlet pipe (10) and opens toward a downstream side of the refrigerant gas outlet pipe (10). 4. An auxiliary evaporator (52) is provided in the auxiliary evaporator (52).
4. The liquid-filled evaporator according to claim 1, further comprising a liquid level detector (15) for detecting the liquid level height of (2) and controlling the liquid level controller (17).