JP3048658B2 - 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 having a bypass pipe commonly called a "saturation temperature generating circuit" in a refrigerating cycle.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 63-290359 discloses a refrigerating apparatus provided with a bypass pipe commonly called a "saturation temperature generating circuit" in a refrigerating cycle.

The refrigerating apparatus disclosed in this publication has a bypass pipe extending from a discharge pipe of a compressor constituting a refrigerating cycle to a suction pipe, and the bypass pipe passes through an auxiliary heat exchanger and the auxiliary heat exchanger. A pressure reducing element for reducing the pressure of the refrigerant and a sensor I for detecting the temperature of the refrigerant passing through the pressure reducing element are provided, while the suction pipe is provided with a sensor II for detecting the temperature of the sucked refrigerant. The valve opening of the expansion valve of the refrigeration cycle is controlled on the basis of the difference between the temperatures detected at II and II.

In this way, the sensor I detects the low pressure saturation temperature in the refrigeration cycle.

Further, the applicant has proposed Japanese Patent Application No. 2-199504 as an improvement of this apparatus. In this proposal, a radiator and a sensor III for detecting the temperature of the refrigerant flowing out of the radiator are provided in one branch pipe by branching the bypass pipe, and a condensed liquid refrigerant is provided in the other branch pipe. A liquid reservoir for storing is provided. The two branch pipes are merged and connected to a suction pipe of a compressor via a decompressor.

[0006]

[Problems to be Solved by the Invention] Japanese Patent Application No. Hei 2-19950
In the device proposed in No. 4, since one of the branch pipes is provided with a radiator, the pipe resistance of one of the branch pipes is larger than the pipe resistance of the other branch pipe. Therefore, it becomes difficult for the refrigerant to flow in one branch pipe than in the other branch pipe, and the sensor III may not be able to reliably detect the high-pressure saturation temperature of the refrigeration cycle.

An object of the present invention is to reliably detect a high-pressure saturation temperature in a refrigeration cycle and to control an expansion valve or the like of the refrigeration cycle based on this temperature.

[0008]

In order to achieve the above object, the present invention provides a refrigerating apparatus having a compressor, wherein a pipe branching from a discharge pipe of the compressor and returning to the compressor is provided. the refrigerant guided to the line pressure in the conduit
A heat exchanger for condensing with the refrigerant sucked into the compressor , a detector for detecting the temperature of the condensed refrigerant, and a trap that is located downstream of the detector and stores the condensed liquid refrigerant may be provided. It was made.

Further, the capacity of the compressor is adjusted based on the value detected by the detector.

[0010]

[0011]

A part of the refrigerant discharged from the compressor is guided to a saturation temperature generating circuit, where the refrigerant exchanges heat with the refrigerant returning to the compressor in a heat exchanger to be condensed and liquefied, and the temperature of the refrigerant is detected by a detector. Moreover, the trap provided in this saturation temperature generation circuit allows
Liquid refrigerant does not accumulate, and the refrigerant detected by the detector does not flow to the discharge pipe faster than a predetermined speed, and the refrigerant does not flow back to the saturation temperature generation circuit from the discharge pipe.

Further, the capacity of the compressor is adjusted based on the value detected by the detector.

[0013]

[0014]

In FIG. 1, reference numeral 1 denotes a multi-type air conditioner (refrigeration unit), one outdoor unit 2, a plurality of indoor units 3, 4, and these indoor units 3, 4 and the outdoor unit 2. And branch kits 5 and 6 provided therebetween. From the outdoor unit 2, a high-pressure gas pipe 7, a low-pressure gas pipe 8, and a liquid pipe 9 extend.

The branch kits 5 and 6 are respectively led to branch pipes of a high-pressure gas pipe 7, a low-pressure gas pipe 8 and a liquid pipe 9, and within the branch kits 5 and 6, the two gas pipes 7 and 8 are branched. The pipes are merging. Reference numeral 10 denotes a heating opening / closing valve provided in a branch pipe of the high-pressure gas pipe 7, and is opened when the indoor unit 3 connected to the branch kit 5 is heated. Reference numeral 11 denotes a cooling opening / closing valve provided in a branch pipe of the low-pressure gas pipe 8, and is opened when the indoor unit 4 connected to the branch kit 6 is cooled.

The indoor units 3 and 4 contain an indoor (use side) heat exchanger 12 and an electrically driven indoor expansion valve 13, and are connected to a branch pipe of the liquid pipe 9 and branch kits 5 and 6. .

The outdoor unit 2 contains the following devices. Numeral 14 denotes a variable capacity compressor in which a signal from the frequency converter 15 is inputted to change the number of revolutions of a motor (not shown), and 16 is a rated (constant capacity type) compressor, and both compressors are connected in parallel. An oil separator 18 is disposed in the merge discharge pipe 17. 19 is both compressors 1
This is an oil equalizing pipe that connects 4,16. Reference numeral 20 denotes an oil return pipe extending from the oil separator 18, and one branch pipe is connected to a suction pipe 22 of the variable capacity compressor 14 via an on-off valve 21, and the other branch pipe is a capillary tube 23.
Through the suction pipe 24 of the rated compressor 16.

The high-pressure gas pipe 7 branches off from the merged discharge pipe 17. Reference numeral 25 denotes a switching valve (one of the four-way switching valves having one connection port closed) provided in the merged discharge pipe 17.
The low-pressure gas pipe 8 extends from the first connection port, and the refrigerant pipe (merging pipe) 26 from the second connection port branches, and its outlet branch pipe 2
7 are connected to respective water heat exchangers 28, 29. Reference numeral 30 denotes a temperature detector provided in the merging pipe 26, and detects a temperature in a state where the refrigerant from the respective water heat exchangers 28 and 29 is merged. The water heat exchangers 28 and 29 function as heat source side heat exchangers in the refrigeration cycle, and electrically driven outdoor expansion valves 32 and 33 are provided at the inlet branch pipes 31 of the water heat exchangers 28 and 29, respectively. Is provided. The inlet branch pipes 31 are joined and connected to the liquid pipe 9. 34
Is a bypass pipe connecting the liquid pipe 9 and the low-pressure gas pipe 8,
An on-off valve 35 is provided. The control of the on-off valve 35 will be described later. 36 is a receiver tank provided in the liquid pipe 9. 37 is a water supply pipe for supplying water to the water heat exchangers 28 and 29.

Reference numeral 38 denotes an outdoor control device which controls the degree of opening of the outdoor expansion valves 32 and 33 based on a signal from the outdoor control device 38. The outdoor control device 38 includes the outdoor expansion valve 32,
The first control means 39 for setting the initial opening of the valve 33, and the control of the opening of one of the two outdoor expansion valves 32, 33 is stopped when the load is equal to or less than a predetermined value, ie, 1
Second control means 40 for controlling only two outdoor expansion valves,
And third control means 41 for controlling the degree of opening of the two outdoor expansion valves 32 and 33 based on a temperature detector provided in the junction pipe. These three control means will be described later.

Reference numeral 42 denotes a suction pipe extending from the low-pressure gas pipe 8,
It is connected to an accumulator 43. 44 is a first saturation temperature generation circuit, 45 is a second saturation temperature generation circuit,
The inlet sides 46 of both circuits 44 and 45 are joined and connected to a discharge pipe 47 of the variable capacity compressor 14. The outlet side 48 of the first saturation temperature generating circuit 44 is a conduit returning to the discharge pipe 47 of the variable capacity compressor 14 again.
The outlet side 49 of the second saturation temperature generation circuit 45 is connected to the suction pipe 42.
Is connected to

The first saturation temperature generation circuit 44 includes a first heat exchanger 50 and a first temperature detector for detecting the temperature of the refrigerant discharged from the heat exchanger 50 (high-pressure saturation temperature of the refrigerant). 51. Reference numeral 52 denotes a high-temperature side controller to which the value detected by the first temperature detector 51 is input. The output from the controller 52 is input to the frequency converter 15.

The second saturation temperature generating circuit 45 includes a second heat exchanger 53, a capillary tube 54 for reducing the pressure of the refrigerant discharged from the heat exchanger 53, and a refrigerant tube for reducing the pressure of the refrigerant discharged from the capillary tube 54. A second temperature detector 55 for detecting the temperature (low-pressure saturation temperature of the refrigerant). Reference numeral 56 denotes a low-temperature side controller to which the value detected by the second temperature detector 55 and the value detected by the third temperature detector 57 provided in the suction pipe 42 are input. The difference between these input values is obtained and input to the third control means 41 of the outdoor control device 38.

The first and second heat exchangers 50,
Reference numeral 53 denotes a so-called double-pipe heat exchanger. The refrigerant returned to the compressors 14 and 16 flows inside, and the refrigerant discharged from the variable capacity compressor 14 flows outside. Then, both circuits 4 discharged from the variable capacity compressor 14 are discharged.
The refrigerant flowing into the compressors 4 and 45 exchanges heat with the refrigerant returned to the compressors 14 and 16 to condense.

Reference numeral 58 denotes a release pipe, the inlet end of which is connected to the inlet pipe of the first heat exchanger 50 of the first saturation temperature generating circuit 44.
The outlet ends are connected to suction pipes at positions upstream of the third temperature detector 57, respectively.

In the air conditioner having such a configuration, not only all the indoor units 3 and 4 can simultaneously perform the cooling operation or the heating operation (the total cooling operation / the total heating operation), but also the one indoor unit 3 performs the cooling operation. The other indoor unit 4 can be operated for heating (cooling / heating or mixed heating / cooling operation). Hereinafter, these operating states will be described.

First, when all the indoor units 3 and 4 are in the heating operation, or when only one indoor unit (for example, the indoor unit 4) is operated in the cooling operation based on the heating operation (in the mixed heating and cooling operation), as shown in FIG. Let the refrigerant flow. That is, the heating on-off valve 10 in the branch kit 5 connected to the indoor unit 3 to be operated for heating is opened, the on-off valve 11 for cooling is closed, and the opening and closing for cooling in the branch kit 6 connected to the indoor unit 4 for cooling operation is performed. Open the valve 11 and open and close the heating on-off valve 1
Close 0. In addition, the indoor expansion valve 13 of the indoor unit 3 to be heated is set to the fully opened state, and the opening degree of the indoor expansion valve 13 of the indoor unit 4 to be cooled is adjusted. Therefore, the outdoor expansion valves 32 and 33 act as the pressure reducing device during the heating only operation, and the outdoor expansion valves 32 and 33 and the indoor expansion valve 13 of the indoor unit 4 that performs the cooling operation operate during the mixed heating and cooling operation. . Further, the switching valve 25 is connected so that the refrigerant flows as indicated by a solid arrow. Further, the switching valve 25 is set so that the refrigerant flows from the merge discharge pipe 17 to the merge pipe 26.

In any of the above-described operations, water (heat source water) is introduced into the water heat exchangers 28 and 29 via the water supply pipe 37.

When the difference between the heating (cooling) load and the heating / cooling (cooling / heating) load is small, the rotational speed of the variable capacity type compressor 14 is controlled in accordance with (following) the load and the rated load is controlled. The operation of the compressor 16 is stopped. The difference between the heating load and the heating / cooling load is a predetermined value (rated compressor 16).
Is exceeded, the compressor 16 of this rating and the variable capacity compressor 14 are operated simultaneously. At this time, the rotational speed of the variable capacity compressor 14 is controlled to a value corresponding to the load only for the amount exceeding the predetermined value.

The initial opening degree of the outdoor expansion valves 32 and 33 acting as a pressure reducing device during the heating operation or the heating / cooling mixed operation is determined by a value detected by the detector 60 of the water supply pipe 37 and a heating load (difference between heating and cooling loads). Is the first control means 39 of the outdoor control device 38
And is controlled as shown in FIG. To give an example,
When the heating load is 5.5 ps and the water temperature is 25 ° C., the initial opening of one outdoor expansion valve 32 is set to about 30%, and the initial opening of the other outdoor expansion valve 33 is set to about 20%.

As described above, the temperature of the (heat source) water supplied to the water heat exchangers 28 and 29 and the heating load are high (low).
Alternatively, the larger (smaller), the larger (smaller) the degree of opening of the outdoor expansion valves 32, 33, and the higher (lower) the heat exchange rate in the water heat exchangers 28, 29. Therefore, the heat exchange capacity of the water heat exchangers 28 and 29 with respect to this heating load was kept substantially appropriate, and an abnormal increase in the refrigerant pressure of the refrigeration cycle could be prevented.

FIG. 4 shows the change in refrigerant pressure immediately after switching from the heating only operation (10 hp) to the mixed heating / cooling operation (heating 6.5 hp, cooling 3.5 hp). When the initial opening degree of the outdoor expansion valves 32 and 33 is changed according to the water temperature and the heating load (the present invention), the high pressure of the refrigerant becomes 3
0 kg / cm ² or less, but the outdoor expansion valve 32,
In the case where the initial opening degree of 33 is kept constant irrespective of the water temperature and the heating load (conventional), the high-pressure pressure of the refrigerant abnormally rises and the high-pressure protection device operates to stop the operation.

FIG. 5 shows the outdoor expansion valves 32, 33 when all the indoor units 3, 4 are operated for cooling or when only one indoor unit 4 is operated for heating based on this cooling operation.
3 shows the initial opening degree.

The mutual opening control of the two outdoor expansion valves 32, 33 having the initial opening set in this way is performed according to the load (for example, the difference between the total horsepower of the heating unit and the total horsepower of the cooling unit). Thus, it is determined by the second control means 40 of the outdoor control device 38. That is, as shown in FIG. 6, when the horsepower difference (load) of the heating unit is 5 horsepower or less,
Only the degree of opening of one of the outdoor expansion valves 32 is controlled, and the degree of opening of the other outdoor expansion valve 33 is maintained at the initial degree of opening. Is exceeded, the opening degree of the other outdoor expansion valve 33 is controlled while keeping one of the outdoor expansion valves 32 substantially fully open. That is, the control of the outdoor expansion valves 32 and 33 is ordered. This is because when the load is small, the refrigerant is supplied to the water heat exchanger 2.
This is to avoid a parallel flow to 8,29. If the refrigerant flows in parallel to the plurality of water heat exchangers 28 and 29 when the load is small, the heat exchange rate in the water heat exchangers 28 and 29 becomes too good, and the degree of superheat of the refrigerant increases (total heating). This is because the discharge temperature of the refrigerant discharged from the compressors 14 and 16 may unnecessarily increase during the warming / cooling mixed operation.

The individual control of the outdoor expansion valves 32 and 33 is performed based on the mutual opening control of the outdoor expansion valves 32 and 33 described above. That is, the respective outdoor expansion valves 32, 33
Is controlled by the third control means 41 of the outdoor control device 38. The third control means 41 includes a detection value of the temperature detector 30 provided in the merging pipe 26 of the outlet branch pipe 27 of the water heat exchangers 28 and 29 and a second detection value provided in the second saturated temperature generation circuit. And the detection value of the temperature detector 55,
The difference between the two is detected and the control as shown in the flowchart of FIG. 7 is output. More specifically, the temperature difference between the two detected values is detected in a block 61, and if the difference is less than 3 ° C., the opening degrees of the outdoor expansion valves 32 and 33 are reduced (block 6).
2) If the temperature is 3 ° C. or more and less than 5 ° C., the opening is maintained (block 63). If the temperature is 3 ° C. or more, the opening is increased (block 64).

Here, the temperature detector 30 for detecting the refrigerant temperature at the outlet side of the water heat exchangers 28, 29 is generally attached to the outlet branch pipes 27 of the respective water heat exchangers 28, 29. It is conceivable that the present invention attaches the temperature detector 30 to the merging pipe 26 of the outlet branch pipe 27,
The number of parts and the control are simplified. The reason why the temperature detector 30 is attached to the junction pipe 26 is that even if the amount of water flowing into the water heat exchangers 28 and 29 greatly changes, the heat exchange rate (capacity ratio) of the heat exchanger is proportional to the change. ) Does not change. That is, FIG. 8 shows the water heat exchanger 28,
29 is operated as an evaporator (at the time of all heating or heating / cooling mixed operation), and the capacity ratio is 10 when the water amount is 100%.
Assuming 0%, the capacity ratio is about 9 even if the water volume drops to 50%.
It decreases only to about 5% to 97%, and the amount of water is reduced to 150%
The capacity ratio increased only up to about 102% to 103%. Similar results were obtained when the water heat exchanger was operated as a condenser (when cooling and heating were mixedly operated) (see FIG. 9).

From this result, when the water heat exchangers 28, 29 are connected in parallel, even if the amount of water flowing into each of the water heat exchangers 28, 29 changes, the respective water heat exchangers 28, 29 change. 2
9 does not fluctuate greatly, so it is sufficient to provide a refrigerant temperature detector 30 at the merging pipe 26 of the water heat exchangers 28, 29 connected in parallel.

When the load difference between the indoor units 3 and 4 is small (heating load> cooling load) during the mixed heating and cooling operation (see FIG. 1), the water heat exchangers (evaporators) 28 and 29 are connected. The amount of the refrigerant flowing in is reduced by being throttled by the outdoor expansion valves 32 and 33. However, the degree of superheat at the outlets of the water heat exchangers 28 and 29 becomes very large, and as a result, the discharge temperatures of the compressors 14 and 16 increase. . Therefore, in the present invention, the discharge temperature control of the compressor shown in FIG. 10 and the control of the indoor expansion valve of the indoor unit during the cooling operation shown in FIG. 11 are performed to prevent the discharge temperature of the compressor from rising. I have.

That is, the discharge temperature of the compressor 14 is detected by a temperature detector 65 provided in the discharge pipe 47 of the variable capacity compressor 14, and as shown in FIG.
When the temperature rises to more than ℃, the on-off valve 35 of the bypass pipe 34 is opened (ON) to allow the liquid refrigerant in the liquid pipe 9 to escape to the low-pressure gas pipe 8,
Increase the low pressure of the refrigerant. At the same time, FIG.
When the discharge temperature of the compressor 14 rises to 115 ° C. or higher as shown by, the indoor expansion valve of the indoor unit during the cooling operation is set to about 3
The opening degree is increased for 0 second (block 66), and the discharge temperature is controlled to 100 ° C. or lower.

The above-mentioned two saturation temperature generating circuits 44 and 4
FIG. 12 shows the connection of the pipes 5 and the vicinity thereof, and FIG. 13 shows the state of the refrigerant detected by the detector provided near this circuit. Part of the refrigerant flowing through the discharge pipe 47 of the variable capacity compressor 14 flows in parallel to the first saturation temperature generation circuit 44 and the second saturation temperature generation circuit 45 (see solid arrows). Here, first, the refrigerant flowing into the first saturation temperature generation circuit 44 is condensed and liquefied in the first heat exchanger 50, and the liquefied refrigerant 68 is stored in the trap 67.
A part of the stored liquid refrigerant 68 is returned to the discharge pipe 47. Here, since the first temperature detector 51 is provided above the trap 67, the refrigerant condensed and liquefied in the first heat exchanger 50 by the liquid refrigerant 68 stored in the trap 67 is faster than a predetermined speed. There is no possibility that the refrigerant will not flow out to the discharge pipe 47 and that the refrigerant will flow backward from the discharge pipe 47 to the first saturation temperature generation circuit 44. Accordingly, the value detected by the first temperature detector 51 becomes the state of the refrigerant at the point indicated by A on the Mollier diagram in FIG. 13, and the high-pressure saturation temperature of the refrigerant can be reliably detected. Further, since the length L0 of the second heat exchanger 53 in the second saturation temperature generation circuit 45 is set to be smaller than the length H of the first heat exchanger 50, The refrigerant flowing out of 53 is a gaseous refrigerant as shown by B in FIG. Since the second temperature detector 55 is provided immediately near the suction pipe 42, the state of the refrigerant at the point D in FIG. 13, that is, the low-pressure saturation temperature can be detected.

As described above, the present invention is provided with the first saturation temperature generation circuit 44 which branches off from the discharge pipe 47 of the compressor 14 and returns to the discharge pipe 47 again via the first heat exchanger 50.
In this circuit, the condensed liquid refrigerant 6
8 is provided, the trap 67 is provided.
The high-temperature saturation temperature of the refrigerant can be reliably detected by the temperature detector 51 provided on the inflow side of the trap 67 by the liquid refrigerant 68 stored in the trap 7.

In particular, during the heating operation or the mixed heating / cooling operation, the high-pressure saturation temperature H thus detected and the temperature detected by the temperature detector 69 of the heat exchanger 12 of the indoor units 3 and 4 (the condensation temperature of the refrigerant) ) Is input to a fourth controller 70, and a signal from this controller 70 is
Is input to the variable-capacity compressor 14 through the controller to control the rotation speed of the compressor 14.

That is, the fourth controller 70 performs control as shown in FIG. High pressure saturation temperature H is 62.5
If the temperature is not less than 60 ° C. and the highest value of the temperatures of the heat exchangers 12 of the indoor units 3 and 4 is not less than 58 ° C., the frequency is decreased at a rate of 10 Hz / 30 seconds in block 80, and the temperature is reduced to 56 ° C.
If the temperature is not lower than 58 ° C, the frequency is lowered at a speed of 5 Hz / 30 seconds. If the temperature is 54 ° C or higher, the frequency is lowered at a speed of 2 Hz / 30 seconds.
In the following cases, the frequency reduction is stopped, and when the temperature is 52 ° C. or lower, general frequency control is performed (see FIG. 15).
By performing such control, the process returns to the detection of the high-pressure saturation temperature H. On the other hand, if the high-pressure saturation temperature is 62.5 ° C. or lower, the frequency control shown in FIG.

As described above, the present invention detects the high-pressure saturation temperature H of the refrigerant in the outdoor unit 2, and based on the detected value and the temperature of the heat exchanger (condenser) of the indoor unit, the variable capacity compression type. The rotation speed of the machine 14 is controlled.

Therefore, the possibility that the high pressure of the compressor 14 rises more than necessary can be reduced.

Conventionally, the heat exchanger 12 of the indoor units 3 and 4
The rotation speed of the compressor 14 was controlled based on the temperature of the (condenser). For this reason, the piping length between the units such as the high-pressure gas pipe 7 and the low-pressure gas pipe 8 connecting the outdoor unit 2 and the indoor units 3 and 4 becomes longer, and the amount of heat radiated from these pipes increases, so that the condenser is temporarily stopped. , The rotational speed of the compressor 14 is increased more than necessary to raise this temperature, and the high-pressure pressure may rise abnormally.

12 and 1, the outlet end 71 of the release tube 58 is connected to the upstream side of the second detector 55, and the release tube 58 is provided with an on-off valve 72. The on-off valve 72 is opened when the compressor 14 is in a high load operation, and a part of the refrigerant discharged from the compressor 14 is transferred to the suction pipe 42 of the compressor 14 via the discharge pipe 47 and the release pipe 58. By returning, the capacity of the compressor 14 (refrigeration device) is suppressed. Here, since the outlet end 71 of the release tube 58 is provided upstream of the second detector 55, the detector 55 can also detect the temperature of the refrigerant flowing through the release tube 58.

Therefore, when the temperature of the refrigerant flowing through the release pipe 58 rises, this rise is detected by the detector 55, and the opening degrees of the outdoor expansion valves 32 and 33 are increased to prevent the rise of the suction temperature. Can be prevented.

On the other hand, the outlet end 71 of the release pipe 58
Is provided on the downstream side of the detector 55, the release pipe 58
Cannot be detected by this detector 55. For this reason, when the refrigerant flowing through the release pipe 58 is in an overheated state, the temperature of the refrigerant discharged from the compressor 14 excessively increases, and conversely, the release pipe 58
When the refrigerant flowing through the compressor is in a supercooled state, the liquid refrigerant may return to the compressor.

[0049]

As described above, according to the present invention, a pipe is provided which branches off from the discharge pipe of the compressor constituting the refrigeration cycle and returns to the compressor again, and this pipe is led to this pipe. Heat exchanger for condensing the refrigerant with the refrigerant sucked into the compressor, a detector for detecting the temperature of the condensed refrigerant, and a trap located downstream of the detector for storing the condensed liquid refrigerant Is provided, it is possible to reliably detect the high-pressure saturation temperature of the refrigerant flowing through this conduit by the liquid refrigerant accumulated in the trap.

Further, since the capacity of the compressor of the refrigeration cycle is adjusted based on the value detected here, abnormal rise of the high-pressure refrigerant in the refrigeration cycle can be prevented. In addition, since the refrigerant sucked into the compressor is heated by a part of the refrigerant discharged from the compressor by the heat exchanger provided to detect the high-pressure saturation temperature, the refrigerant sucked into the compressor is reliably gasified. Liquid compression can be prevented.

[0051]

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing a flow of a refrigerant when heating an air conditioner (refrigeration apparatus) according to the present invention.

FIG. 2 is a refrigerant circuit diagram showing the flow of refrigerant during cooling of the air-conditioning apparatus (refrigeration apparatus) according to the present invention.

FIG. 3 is an explanatory diagram showing an initial opening degree of the outdoor expansion valve shown in FIG.

FIG. 4 is an explanatory diagram showing a pressure change state of a refrigerant of the air-conditioning apparatus shown in FIG.

FIG. 5 is an explanatory diagram showing an initial opening degree of the outdoor expansion valve shown in FIG.

FIG. 6 is a diagram showing a mutual control relationship between two outdoor expansion valves shown in FIG. 1;

FIG. 7 is a flowchart showing control of the outdoor expansion valve shown in FIG.

FIG. 8 is a view showing a relationship between a water amount ratio and a capacity ratio when the water heat exchanger shown in FIG. 1 is operated as an evaporator.

FIG. 9 is a diagram showing a relationship between a water amount ratio and a capacity ratio when the water heat exchanger shown in FIG. 1 is operated as a condenser.

FIG. 10 is a diagram showing an open / closed state of the on-off valve shown in FIG. 1;

FIG. 11 is a flowchart showing control of the indoor expansion valve shown in FIG.

FIG. 12 is a pipe connection diagram near two saturation temperature generation circuits shown in FIG. 1;

FIG. 13 is a Mollier chart showing a refrigerant pressure state in the pipe shown in FIG.

FIG. 14 is a flowchart showing frequency control of the compressor shown in FIG. 1;

FIG. 15 is a control diagram of a block 80 shown in FIG. 14;

FIG. 16 is a control diagram of a block 81 shown in FIG. 14;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 air conditioner (refrigeration unit) 12 indoor heat exchanger 14 variable capacity compressor 28, 29 water heat exchanger 32, 33 outdoor expansion valve 42 suction pipe 44 first saturation temperature generation circuit (pipe) 47 discharge pipe Reference Signs List 50 first heat exchanger 51 first temperature detector 57 third temperature detector 58 release tube 67 trap 70 fourth controller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-41861 (JP, A) JP-A-63-143461 (JP, A) Fully open Showa 61-178159 (JP, U) Really open Showa 63- 116864 (JP, U) Japanese Utility Model Showa 54-22254 (JP, U) Japanese Utility Model Showa 52-41557 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/00 371 F25B 1/00 304 F25B 49/02 510

Claims (2)

(57) [Claims] 1. A refrigeration system having a compressor, a conduit back again branched from the discharge pipe of the compressor on the compressor provided, the pressure of the refrigerant introduced into the conduit for this conduit
A heat exchanger for condensing with the refrigerant sucked into the compressor , a detector for detecting the temperature of the condensed refrigerant, and a trap located downstream of the detector for storing the condensed liquid refrigerant are provided. A refrigeration apparatus characterized by the above-mentioned. 2. A refrigerating apparatus having a variable capacity compressor, a pipe branching from a discharge pipe of the compressor and returning to the compressor is provided, and the pipe is led to the pipe. Heat exchange in which refrigerant is condensed by refrigerant sucked into the compressor
And a controller for adjusting the capacity of the compressor based on a value detected by the detector. .