JP3218871B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus, and more particularly to a measure for improving the performance of a heat exchanger functioning as an evaporator.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Publication No.
The refrigeration apparatus provided in an air conditioner or the like as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2000-163, includes a refrigerant circuit in which a compressor, a condenser, an expansion valve whose opening is adjustable, and an evaporator are sequentially connected by refrigerant piping. I have. The condenser and the evaporator are provided with a plurality of refrigerant tubes through which the refrigerant can flow freely, and each of the downstream ends of each of the refrigerant tubes is connected to a gas header. Are merged. The gas header is connected to the refrigerant pipe by one connecting pipe. A means for detecting the degree of superheat of the refrigerant gas, such as a temperature-sensitive cylinder, is attached to the communication pipe downstream of the evaporator.

[0003] When operating this type of refrigeration system,
The degree of superheat of the refrigerant gas flowing through the communication pipe on the downstream side of the evaporator is detected by a temperature sensing tube or the like, and the opening of the expansion valve is controlled based on the degree of superheat. In other words, when the degree of superheat is high, the opening of the expansion valve is increased. The heat exchange efficiency between the air and the refrigerant in the air is increased.

[0004]

However, the above-described configuration has the following problems.

That is, a pressure loss occurs when the refrigerant is led out from the inside of the gas header, which is a relatively large space, to the connecting pipe, thereby reducing the circulation amount of the refrigerant and deteriorating the performance of the refrigeration system.

[0006] In order to solve this problem, it is conceivable to increase the diameter of the connecting pipe. However, in this case, when it is necessary to bend the connecting pipe, the connecting pipe is processed by an existing processing machine. In this case, a new machine for bending a large-diameter pipe is required.

Another problem is that, especially when the heat exchanger on the heat source side functions as an evaporator, the flow velocity of the air passing through the evaporator varies in each part (for example, upper and lower parts) of the evaporator. It may be different, and in such a situation, the evaporation state of the refrigerant in each refrigerant pipe in the evaporator is also different. That is, the degree of superheat of the refrigerant varies depending on the refrigerant pipe. In the above-described conventional configuration, the refrigerant in each refrigerant pipe having a difference in the degree of superheat is merged at the gas header, and the degree of superheat of the merged refrigerant is detected at the communication pipe downstream of the gas header. Therefore, among the refrigerant pipes, a refrigerant pipe having a large amount of heat exchange between the refrigerant and the air and having a high degree of superheat tends to have insufficient capacity.

[0008] That is, in the heat exchanging amount is large refrigerant tube Despite becomes higher degree of superheat of the refrigerant actually superheat of the refrigerant after the confluence to be detected is lower than that, the low superheat The opening degree of the expansion valve is adjusted based on the above.
For this reason, in this refrigerant pipe, although it was originally a part having a high heat exchange efficiency, it could not be fully utilized, so that the heat transfer coefficient on the refrigerant side was lowered and the evaporator as a whole was reduced. Performance could not be fully obtained.

When the opening of the expansion valve is controlled based on the degree of superheat of the refrigerant gas, the set value of the degree of superheat is set to 0.
If the temperature is set near ℃, the performance of the evaporator can be fully utilized. However, in such control, the refrigerant at the evaporator outlet side actually exists in a wet state, so that an accurate refrigerant temperature cannot be detected, and the superheat degree control cannot be performed accurately. Therefore, in this superheat degree control, it is necessary to set the set value of the superheat degree to, for example, about 5 ° C. If such a relatively high set value is used, the above-described problem can be solved by the conventional configuration. Could not.

The present invention has been made in view of these points, and by improving the configuration of the peripheral portion of the evaporator, the connection pipe is led out of the gas header to the connection pipe without increasing the diameter of the connection pipe. Even if the pressure loss of the refrigerant can be reduced and the degree of superheat of the refrigerant in each refrigerant pipe in the evaporator is different, the refrigerant is kept at a relatively high superheat degree control setting value. An object is to maintain a high side heat transfer coefficient and sufficiently obtain the performance of the entire evaporator.

[0011]

In order to achieve the above object, the present invention provides a plurality of communication pipes on the downstream side of the gas header, and among them, only the refrigerant having the highest degree of superheat is circulated. The degree of superheat is detected, and the degree of opening of the expansion valve is adjusted based on the detected degree of superheat. Specifically, as shown in FIG. 1, the invention according to claim 1 includes a compressor (2) and a plurality of refrigerant pipes (7a), (7
a) a heat source side heat exchanger (7) having ... and refrigerant tubes (7a), (7a) ...
A gas header (23) connected to the gas side, an expansion valve (15a) whose degree of opening can be adjusted, and a refrigerant circuit (1) in which a use side heat exchanger (4) is connected. The degree of superheat is detected by superheat degree detecting means (16), and based on the degree of superheat, the expansion valve
(15a) is premised on a refrigeration device whose opening is adjusted. Then, a plurality of connecting pipes (24), (25) extending toward the compressor (2) are connected to the gas header (23), and the superheat degree detecting means (16) is connected to the heat source side heat exchanger ( A superheat degree detector (15f) provided on the gas side of 7) is provided. Also, the expansion valve
(15a) is a temperature-sensitive type, the superheat degree detector (15f)
Adjusts the opening of the expansion valve (15a) based on the refrigerant temperature
The temperature sensing tube is configured so as to be provided in one of the communication tubes (24) and (25) through which the refrigerant having the highest degree of superheat flows.

According to a second aspect of the present invention, the compressor (2)
Heat source side having a plurality of independent refrigerant pipes (7a), (7a) ...
Connected to the heat exchanger (7) and the gas side of the refrigerant pipes (7a), (7a) ...
Gas header (23), an expansion valve (15a) with adjustable opening,
Equipped with a refrigerant circuit (1) connected to the user-side heat exchanger (4)
The superheat degree of the refrigerant gas is detected by the superheat degree detection means (16).
The expansion valve (15a) is adjusted for opening based on the degree of superheat.
It is assumed that a refrigeration system is used. And the gas head
(23) have a plurality of connecting pipes extending toward the compressor (2).
(24), (25) are connected, the superheat degree detection means (16)
Is the degree of superheat provided on the gas side of the heat source side heat exchanger (7).
A detector (15f) is provided. Further, the heat source-side heat exchanger (7) flows a refrigerant flowing through the plurality of refrigerant tubes (7a), the internal (7a) ..., the plurality of refrigerant tubes (7a), a (7a) ... external being adapted to perform heat exchange with the air, the respective refrigerant pipes (7a), (7a) ... flow velocity distribution respective refrigerant tube of the air flowing through the external (7a), in people (7a) ... husband Is different . In addition
The superheat degree detector (15f) is connected to each of the communication pipes (24) and (25).
Of the refrigerant with the highest degree of superheat
Is, connection pipe that the superheat degree detector (15f) is provided (24),
Gas header corresponding to refrigerant pipe (7a) with high air flow rate
The configuration is connected to (23).

According to a third aspect of the present invention, in the refrigeration apparatus according to the second aspect, the heat source side heat exchanger (7) is provided with an air inlet (21a) on a side surface and an air outlet (21b) on an upper surface. ) Are formed in the unit casing (21) in which the refrigerant pipes (7a), (7a)... Extending in the horizontal direction are opposed to the air suction port (21a) so as to be arranged in a vertical direction. Gas header (2
3) is vertically extended to face each of the refrigerant pipes (7a), (7a)..., And the connecting pipes (24), (25) are spaced apart in the vertical direction of the gas header (23). Arrange a plurality of them. The superheat degree detector (15f) is provided in the connecting pipe (24) where the connection position to the gas header (23) is located at the top.

According to a fourth aspect of the present invention, in the refrigeration apparatus according to the second or third aspect, the expansion valve (15a) is of a temperature-sensitive type, and the superheat detector (15f) is controlled based on the refrigerant temperature. The expansion valve (15a) is configured as a temperature-sensitive cylinder for adjusting the opening.

[0015]

According to the above construction, the following effects can be obtained in the present invention. According to the first aspect of the present invention, for example, during a heating operation of the refrigeration system, the high-pressure refrigerant discharged from the compressor (2) is condensed and liquefied in the use-side heat exchanger (4), and this liquid refrigerant is expanded. After the pressure is reduced by the valve (15a), it is evaporated in the heat source side heat exchanger (7) and returns to the compressor (2). During this operation cycle, the refrigerant led out of the heat source side heat exchanger (7) is supplied to a plurality of refrigerant pipes (7a), (7
a), ... are introduced into the gas header (23), and then returned to the compressor (2) through a plurality of communication pipes (24), (25). Therefore, a large flow path on the downstream side of the gas header (23) can be secured without increasing the diameter of the connecting pipes (24) and (25), so that the connecting pipes (24) and (25) can be connected from the gas header (23). Pressure loss when the refrigerant is discharged is reduced, and a large circulation amount of the refrigerant is ensured.
When the degree of superheat of the refrigerant is different due to the refrigerant pipes (7a), (7a), ..., the degree of superheat of the refrigerant for adjusting the opening degree of the expansion valve (15a) is the highest degree of superheat. Is detected by the heating degree detector (15f) in the communication pipe (24) through which the refrigerant having a high degree of heat flows, so that the refrigerant pipe (7
The adjustment of the opening degree of the expansion valve (15a) is optimized for (a). That is, the degree of superheat of the refrigerant in the refrigerant pipe (7a) and the degree of superheat of the refrigerant after merging can be set low, thereby increasing the refrigerant-side heat transfer coefficient and improving the performance of the entire evaporator.

Further, the temperature sensing cylinder (15f) detects the expansion valve (15a).
Temperature-sensitive type that adjusts the opening according to the refrigerant temperature
Therefore, the opening of the expansion valve (15a) can be adjusted with a simple configuration.
it can.

In the invention according to claim 2, each refrigerant pipe (7a),
(7a) ... the wind velocity distribution of the air flowing outside the refrigerant pipes (7a),
In a situation where the degree of superheat of the refrigerant in each of the refrigerant pipes (7a), (7a), ... is different due to the difference in each of (7a) ..., the superheat degree detector (15f) Connecting pipe (2
4) is connected to the gas header (23) in correspondence with the refrigerant pipe (7a) having a high air flow rate, so that the refrigerant is superheated in the connecting pipe (24) through which the refrigerant with the highest degree of superheat flows. Degree can be detected.

According to the third aspect of the present invention, the heat source side heat exchanger
(7) is a side suction / upward blow type unit casing (21)
Is disposed at a position facing the air suction port (21a) of the heat source side heat exchanger (7).
The wind speed of the air flowing outside is high, and it is low at the bottom. That is, the refrigerant pipe (7a) located above the heat source side heat exchanger (7) has a particularly high heat exchange efficiency between air and refrigerant, and the refrigerant pipe (7a) has a superheat degree detector (15f). Is installed, the communication pipe (2
In 4), the degree of superheat of the refrigerant can be detected.

According to the invention described in claim 4, claim 2 or
In the invention of the third aspect, since the expansion valve (15a) is a temperature-sensitive type in which the opening is adjusted by the refrigerant temperature detected by the temperature-sensitive cylinder (15f), the opening of the expansion valve (15a) is adjusted with a simple configuration. be able to.

[0020]

Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the refrigeration apparatus is an air conditioner that performs cooling and heating by generating cold and hot water, and includes a refrigerant circuit (1) through which a refrigerant circulates.

The refrigerant circuit (1) includes a compressor (2) and a four-way switching valve.
(3) Water-side heat exchanger (4) and receiver as use-side heat exchanger
(5), an expansion mechanism (6) and two air-side heat exchangers (7) and (7) as heat source-side heat exchangers are connected in order by a refrigerant pipe (8), and a four-way switching valve is provided. (3) is configured to switch as shown by the solid line during the cooling operation and as shown by the broken line during the heating operation to switch the circulation direction of the refrigerant.

The water-side heat exchanger (4) functions as an evaporator during the cooling operation and as a condenser during the heating operation, and is configured so that air-conditioning water flows in and out to exchange heat between the refrigerant and the air-conditioning water. ing.

The two air-side heat exchangers (7), (7) are connected in parallel, and each of the air-side heat exchangers (7), (7) serves as a condenser during a cooling operation and serves as a condenser. It functions as an evaporator during operation and is configured to exchange heat between the refrigerant and the outdoor air.

The liquid receiver (5) is always provided with a high-pressure liquid pipe.
(9), the inlet side of the constantly high-pressure liquid pipe (9) is an air-side liquid pipe (10) communicating with the air-side heat exchanger (7).
And the water-side liquid pipe (11) communicating with the water-side heat exchanger (4) are connected via check valves (12), (12),. Is connected to the expansion mechanism (6). It should be noted that the always high-pressure liquid pipe downstream of the receiver (5)
(9) is provided with a dryer (13).

The expansion mechanism (6) comprises a cooling decompression unit (14) and two parallel heating decompression units (15) and (15).
The refrigerant inflow sides of the cooling decompression unit (14) and the heating decompression units (15) and (15) are connected to the outlet side of the high-pressure liquid pipe (9), while the cooling decompression unit (14) ) Is the water side liquid piping (1
In (1), the refrigerant outflow side of the heating decompression section (15) is connected to the air-side liquid pipe (1).
0).

The cooling decompression section (14) and the heating decompression section (1)
5) includes main pressure reducing passages (14b) and (15b) having temperature-sensitive expansion valves (14a) and (15a), and main pressure reducing passages (14b) and (15
The auxiliary expansion passages (14c) and (15c) are provided in parallel with b).
The auxiliary expansion passages (14c) and (15c) are provided with solenoid valves (14d) and (15d) as opening / closing portions and a capillary tube as a throttle portion.
(14e) and (15e) are connected in series, and the solenoid valve (14
d) and (15d) are for full load operation (100% capacity operation)
And the liquid refrigerant is opened to the main pressure reducing passages (14b) and (15b),
It is configured to flow through the auxiliary pressure reducing passages (14c) and (15c).

The temperature-sensitive cylinder (14f) of the temperature-sensitive expansion valve (14a) in the cooling pressure-reducing section (14) is a suction-side refrigerant pipe (8a) of the compressor (2) and is a four-way switching type. Mounted downstream from valve (3). The temperature-sensitive expansion valve (14a) is configured such that its opening is adjusted according to the degree of superheat of the refrigerant during the cooling operation, and is fully closed during the heating operation.

Further, the compressor (2) is constituted by a screw type compressor and provided with an unloader mechanism (2a).

The unloader mechanism (2a) includes first to fourth unload valves (2c) to (2f) in an unload passage (2b) communicating with the low pressure side and the high pressure side of the compressor (2). ) Is provided. And the unloader mechanism (2a)
Open the first unload valve (2c) to reduce the capacity of the compressor (2) to 1
2%, the second unload valve (2d) is opened to increase the capacity of the compressor (2) to 25%, and the third unload valve (2e) is opened to reduce the capacity of the compressor (2) to 40%. Further, the fourth unload valve (2f) is opened to switch the capacity of the compressor (2) to 70%.

Further, a pressure extraction pipe (2 g) is connected to the low pressure side and the high pressure side of the compressor (2), and the pressure extraction pipe (2
g), a high pressure sensor (SENH) for detecting the high pressure of the refrigerant circuit (1) and a low pressure sensor (SENL) for detecting the low pressure of the refrigerant circuit (1) are provided. Pressure switch that activates when the pressure rises excessively and when the low pressure drops excessively
(HLPS).

Next, the air-side heat exchanger which is a feature of the present embodiment.
(7) and the surrounding structure will be described. First, FIG.
Outdoor unit equipped with an air-side heat exchanger (7)
(20) will be described. The outdoor unit (20) is of a so-called side suction / upward discharge type, and has an air suction port (21a) formed by opening a side surface of a unit casing (21). ) Has an air outlet (21b) formed on the upper surface thereof. In addition, this air outlet (21
b) is provided with a fan (22) rotatable by a fan motor (22a). Further, the air-side heat exchangers (7), (7) are arranged in a portion facing the air suction port (21a) in the unit casing (21). With this configuration, in the main outdoor unit (20), air is sucked in from the air suction port (21a) as the fan (22) rotates, and the air passes through the air-side heat exchanger (7). After exchanging heat with the refrigerant, the air is blown out from the air outlet (21b). When the outdoor unit (20) is configured as described above, the upper part of the air-side heat exchanger (7) is close to the fan (22) due to the proximity of the fan (22) as shown in the wind speed distribution shown in FIG. The flow velocity of the air is high, and the distance to the fan (22) increases toward the lower part, so that the flow velocity of the air decreases. That is, the upper part of the air-side heat exchanger (7) is a part where the heat exchange efficiency between the air and the refrigerant is particularly high, and the lower part is a part where the heat exchange efficiency is particularly low.

The feature of this embodiment resides in the configuration of the outlet of the air-side heat exchanger (7) during the heating operation. As shown in FIG. 1, the air-side heat exchanger (7) includes a plurality of refrigerant pipes (7a), (7a),. Each of the outlet-side ends (left side in FIG. 1) of (7a),... Is connected to a vertically extending gas header (23) for joining the refrigerant flowing through each of the refrigerant pipes (7a), (7a),. ing.

As one of the features of this embodiment, the gas header (23) and the refrigerant pipe (8) are connected by a pair of upper and lower two communication pipes (24) and (25). This connecting pipe (24),
Of the (25), the first connecting pipe (24) located on the upper side is connected to a position near the upper end on the side surface of the gas header (23), while the second connecting pipe (25) located on the lower side is connected to the gas header. (twenty three)
Is connected to a substantially central position in the vertical direction on the side surface of the. Further, the connection position of each of the connecting pipes (24) and (25) with respect to the gas header (23) is such that the amount of refrigerant flowing from the gas header (23) in each of the connecting pipes (24) and (25) is substantially equal. The position is set so that

This gas header (23) and each connecting pipe (24), (2
The arrangement configuration 5) will be specifically described with reference to FIGS.
FIG. 3 is a plan view showing the inside of the outdoor unit (20), and FIG.
FIG. 5 is a side view, and FIG. 5 is a view taken in the direction of the arrow V in FIGS. 3 and 4 showing the shape of the connecting pipes (24), (25). As shown in these figures, the first communication pipe (24) extends to the center in the horizontal direction from a position near the upper end on the inner surface of the gas header (23), and then is inclined rightward in FIG. Then, it extends to the center in the horizontal direction and is connected to the refrigerant pipe (8). On the other hand, the second communication pipe (25) extends from the substantially vertical center position on the side surface of the gas header (23) to the center in the horizontal direction, and is inclined rightward in FIG. It extends to the upper side of the pipe (24), then extends to the center in the horizontal direction, and is connected to the refrigerant pipe (8). Then, the refrigerant pipe (8) to which the connecting pipes (24) and (25) are connected extends vertically downward, then horizontally to the right in FIG. 3, and then horizontally to the right in FIG. It extends downward and further extends toward the suction side of the compressor (2) via the four-way switching valve (3).

As another characteristic of the present embodiment, the first communication pipe (24) is provided with a temperature-sensitive expansion valve (15a) of the heating pressure reducing section (15) as a superheat degree detector. A tube (15f) is attached. That is, the opening degree of the temperature-sensitive expansion valve (15a) is adjusted based only on the degree of superheat of the refrigerant returning to the compressor (2) through the first communication pipe (24). Has become. The temperature-sensitive expansion valve (15a) is configured to be fully closed during the cooling operation. Thus, the superheat degree detecting means (16) according to the present invention is constituted by the thermosensitive cylinder (15f) and the above-described thermosensitive cylinder (14f).

Next, the cooling and heating operation of the above-described air conditioner will be described.

First, during the cooling operation cycle, the compressor
The high-pressure refrigerant discharged from (2) is the air-side heat exchanger (7), (7)
This liquid refrigerant is condensed and liquefied by the air side liquid pipe (7),
After passing through the liquid receiver (5) and the dryer (13) through (7), it is guided to the cooling depressurizing section (14) and depressurized, and then the water-side heat exchanger (4)
And the water is returned to the compressor (2) after being evaporated in the water-side heat exchanger (4).

On the other hand, during the heating operation cycle, the compressor
The high-pressure refrigerant discharged from (2) is condensed and liquefied in the water-side heat exchanger (4), and this liquid refrigerant is passed through the water-side liquid pipes (11) and (11), and the liquid receiver (5) And through the dryer (13)
(15), after being decompressed by (15), air side heat exchanger (7)
And evaporates in this air-side heat exchanger (7) and the compressor (2)
Return to the circulation.

In each operation cycle, the unload valves (2c) to (2f) of the unloader mechanism (2a) are switched according to the required refrigerating capacity to control the capacity of the compressor (2). Is done. When the capacity of the compressor (2) is 100% full load, the solenoid valve (14d) of the cooling decompression unit (14) is used for cooling, and the solenoid valve (14) of the heating decompression unit (15) is used for heating.
(15d) is opened, and the refrigerant is depressurized in the capillary tubes (14e) and (15e) together with the temperature-sensitive expansion valves (14a) and (15a), so that a large circulation amount of the refrigerant is secured. When the compressor (2) is in the unloaded state, each solenoid valve (14d),
(15d) is closed, and the pressure of the refrigerant is reduced only in the temperature-sensitive expansion valves (14a) and (15a).

If the high-pressure refrigerant pressure rises or falls too much during the above-mentioned operation cycle, the compressor (2) is forcibly stopped by the operation of the pressure switch (HLPS).

The characteristic operation of the present embodiment lies in the operation of adjusting the opening of the temperature-sensitive expansion valve (15a) during the heating operation. In this operation, as described above, the degree of superheat of the refrigerant detected in the temperature-sensitive cylinder (15f) of the temperature-sensitive expansion valve (15a) for the heating operation passes through the first communication pipe (24) and is compressed. The degree of opening of the temperature-sensitive expansion valve (15a) is adjusted only by the degree of superheat of the refrigerant returning to the compressor (2) through the first communication pipe (24). Done by In addition, this first communication pipe (24)
Is connected to a position near the upper end portion on the side surface of the gas header (23) .The position near the upper end portion on the side surface of the gas header (23) has a high flow velocity of air passing through the air-side heat exchanger (7). A refrigerant pipe in which the degree of superheat of the refrigerant is likely to be large because the heat exchange efficiency between the air and the refrigerant is particularly high.
The position corresponds to the connection part of (7a). Therefore, the opening of the temperature-sensitive expansion valve (15a) is adjusted by adjusting the refrigerant pipes (7a) and (7
a),..., are performed based on the portion of the refrigerant having the highest degree of superheat among the refrigerants joined at the gas header (23).

As described above, according to the configuration of this embodiment, the communication pipe
By providing two (24) and (25), the connecting pipes (24) and (25)
A large refrigerant flow path on the downstream side of the gas header (23) can be secured without increasing the diameter of the gas header (23), so that a new processing machine for bending the connecting pipe is not required, and the gas header (23)
The pressure loss when the refrigerant is led out to the communication pipes (24) and (25) can be reduced, a large amount of refrigerant can be circulated, and the performance of the refrigeration system can be improved.

Since the degree of superheat of the refrigerant for adjusting the opening of the temperature-sensitive expansion valve (15a) is detected in the first communication pipe (24) through which the refrigerant having the highest degree of superheat flows, As shown in FIG. 6, the superheat degree of the refrigerant in the case of the present example shown by the broken line is compared with the conventional one (the refrigerant superheat degree is the average of the superheat degrees of the refrigerant derived from the respective refrigerant pipes) shown by the solid line. The degree of opening of the temperature-sensitive expansion valve (15a) can be set low, especially for the refrigerant pipe (7a) located at the top, where the degree of superheating tends to be high, so that the degree of superheating does not become too high. It can be performed. That is, in FIG. 6, the vertical axis represents the heat exchanger shown in FIG.
The height position of (7) and the horizontal axis indicate the degree of superheat of the refrigerant, respectively. When the superheat degree is controlled so as to be a set value (for example, 5 ° C.) indicated by a dashed line, the height of the heat exchanger The superheat degree (5 ° C) can be set in the high position, and the superheat control value can be set relatively high to enable accurate detection of the refrigerant temperature. The degree of superheat can be set low, and the performance of the evaporator can be fully utilized. As a result, as shown in FIG. 7, the refrigerant-side heat transfer coefficient in the case of the present embodiment shown by the broken line can be increased as compared with the conventional one shown by the solid line, and the performance of the entire refrigeration apparatus can be improved. . In FIG. 7, the vertical axis indicates the height position of the heat exchanger (7), and the horizontal axis indicates the refrigerant-side heat transfer coefficient.

In this embodiment, a temperature-sensitive expansion valve (15) whose opening is adjusted by the refrigerant temperature detected by the temperature-sensitive cylinder (15f).
Although the case where a) is adopted has been described, the present invention is not limited to this, and temperature sensors are provided on both sides of the entrance and exit of the air-side heat exchanger (7), respectively, and the temperature difference of the refrigerant detected by this temperature sensor is used. What detected the degree of superheat of a refrigerant may be adopted.

[0045]

As described above, according to the present invention, the following effects are exhibited. According to the first aspect of the present invention, a plurality of communication tubes are connected to the gas header, and the superheat detector is provided in one of the communication tubes through which the refrigerant having the highest superheat flows. A large flow path on the downstream side of the gas header can be secured without increasing the diameter of the pipe, so the refrigerant is led out of the gas header to the connection pipe without requiring a new processing machine for bending the connection pipe. Pressure loss at the time can be reduced, a large circulation amount of the refrigerant can be secured, and the performance of the refrigeration apparatus can be improved.

Further, the degree of superheat of the refrigerant for adjusting the degree of opening of the expansion valve is detected in the communication pipe through which the refrigerant having the highest degree of superheat flows. Can be set low, and in particular, the opening degree of the expansion valve can be adjusted optimally so that the superheat degree does not become too high for the refrigerant pipe in which the superheat degree of the refrigerant tends to be high. As a result, the refrigerant-side heat transfer coefficient can be increased as compared with the conventional one, while setting the superheat control value relatively high to enable accurate detection of the refrigerant temperature. Can be improved.

Further, the refrigerant temperature at which the temperature sensing cylinder detects the expansion valve
Because it is a temperature-sensitive type that adjusts the opening by
With this configuration, the opening degree of the expansion valve can be adjusted.

According to the second aspect of the present invention, the arrangement position of the superheat degree detector is set in consideration of the fact that the flow velocity distribution of the air flowing outside the respective refrigerant pipes is different in each of the refrigerant pipes. In addition, the degree of superheat of the refrigerant can be reliably detected in the communication pipe through which the refrigerant with the highest degree of superheat flows.

According to the third aspect of the present invention, a side suction / upper discharge type unit having a high heat exchange efficiency between the air and the refrigerant in the refrigerant pipe located above the heat source side heat exchanger is provided.
Since the superheat degree detector is attached to the communication pipe located at the upper part, the superheat degree of the refrigerant can be detected in the communication pipe through which the refrigerant having the highest superheat degree flows.

[0050] According to the fourth aspect of the present invention, claim 2 or
According to the third aspect of the present invention, since the expansion valve is a temperature-sensitive type in which the opening is adjusted by the refrigerant temperature detected by the temperature-sensitive cylinder, the opening of the expansion valve can be adjusted with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a refrigerant piping system diagram of a refrigeration apparatus.

FIG. 2 is a cross-sectional view illustrating an arrangement state of an air-side heat exchanger in an outdoor unit.

FIG. 3 is a plan view showing the inside of the outdoor unit.

FIG. 4 is a side view showing the inside of the outdoor unit.

FIG. 5 is a view taken in the direction of the arrow V in FIGS. 3 and 4;

FIG. 6 is a diagram illustrating a relationship between a height position of a heat exchanger and a degree of superheat of a refrigerant at a cooling pipe outlet side.

FIG. 7 is a diagram showing a relationship between a height position of a heat exchanger and a heat transfer coefficient on a refrigerant side.

[Explanation of symbols]

 (1) Refrigerant circuit (2) Compressor (4) Water side heat exchanger (use side heat exchanger) (7) Air side heat exchanger (heat source side heat exchanger) (7a) Refrigerant tube (15a) Temperature sensing (15f) Thermosensitive cylinder (superheat detector) (16) Superheat detector (21) Unit casing (21a) Air inlet (21b) Air outlet (23) Gas header (24) First connection pipe (25) Second communication pipe

Claims (4)

(57) [Claims] 1. A compressor (2), a heat source side heat exchanger (7) having a plurality of refrigerant tubes (7a), (7a).
(7a), a gas header (23) connected to the gas side of (7a) ...
A refrigerant circuit (1) in which an expansion valve (15a) whose opening is adjustable and a use side heat exchanger (4) are connected is provided, and the degree of superheat of the refrigerant gas is detected by a superheat degree detecting means (16). In the refrigerating apparatus in which the opening of the expansion valve (15a) is adjusted based on the degree of superheating, the gas header (23) includes a plurality of communication tubes (24), (25) extending toward the compressor (2). The superheat detection means (16) is provided with a superheat detector (15f) provided on the gas side of the heat source side heat exchanger (7), and the expansion valve ( 15a) are intended thermostatic, the degree of superheat detector (15f), said inflation based on the refrigerant temperature
A temperature-sensitive cylinder that adjusts the opening of the valve (15a).
5) A refrigeration apparatus provided in a refrigerant through which a refrigerant having the highest degree of superheat flows. 2. A compressor (2) and a plurality of independent cooling units.
A heat source side heat exchanger (7) having medium tubes (7a), (7a) ...
(7a), a gas header (23) connected to the gas side of (7a) ...
The expansion valve (15a) with adjustable opening and the use-side heat exchanger (4)
Equipped with a connected refrigerant circuit (1), the degree of superheat of the refrigerant gas
Is detected by means of superheat detection means (16), and based on the degree of superheat, the expansion valve (15a) is adjusted to open.
In the refrigerating apparatus, the gas header (23) includes a plurality of gas headers extending toward the compressor (2).
Several connecting pipes (24) and (25) are connected, and the superheat detection means (16) is connected to the heat source side heat exchanger (7).
A superheat degree detector (15f)
Write, the heat source-side heat exchanger (7), a plurality of refrigerant tubes (7a), (7a) ... inside and the refrigerant flowing through, the plurality of refrigerant tubes (7a), (7a) ...
The heat exchange is performed between air flowing outside the refrigerant pipes, and the flow velocity distribution of the air flowing outside the refrigerant pipes (7a), (7a). , And the superheat degree detector (15f) is connected to each of the connecting pipes (24) and (25).
That is, the refrigerant having the highest degree of superheat is provided in the refrigerant,
The superheat degree detector connection tube (15f) is provided (24), gas header corresponding to the flow rate of the air is high refrigerant pipe (7a) (23)
A refrigeration apparatus , wherein the refrigeration apparatus is connected to a refrigerator . 3. A heat source side heat exchanger (7) is disposed horizontally in a unit casing (21) having an air inlet (21a) formed on a side surface and an air outlet (21b) formed on an upper surface. Each of the extending refrigerant pipes (7a), (7a)... Is disposed so as to face the air suction port (21a) so as to be arranged side by side in the vertical direction, and the gas header (23) is disposed in each of the refrigerant pipes (7a). , (7a) ..., extending in the vertical direction, and a plurality of connecting pipes (24), (25) are juxtaposed at intervals in the vertical direction of the gas header (23). The refrigerating apparatus according to claim 2, wherein the degree detector (15f) is provided in the communication pipe (24) at a position where the degree of connection to the gas header (23) is located at the uppermost position. 4. The expansion valve (15a) is of a temperature-sensitive type, and the superheat degree detector (15f) detects the expansion valve (15f) based on refrigerant temperature.
claims, characterized in that: a) a temperature sensing tube for adjusting opening
4. The refrigeration apparatus according to 2 or 3.