JPH0566075A - Refrigeration cycle - Google Patents

Abstract

(57) [Abstract] [Purpose] In a refrigerant cycle using a fluorocarbon such as HFC134a as a refrigerant and an open type compressor, the moisture contained in the refrigeration cycle is effectively absorbed and removed by the desiccant. However, seizure of the compressor caused by corrosion of metal parts in the cycle and freezing in the refrigerant flow rate control means is avoided. [Composition] Compressor 1, condenser 2, refrigerant flow rate control means 4,
In a refrigeration cycle composed of an evaporator 5 and a pipe line connecting them, a water removing device 6 for absorbing the water contained in the refrigeration cycle is installed in the low pressure gas pipe 10 from the evaporator 5 to the compressor 1. To install. [Effect] Since the fluorohydrocarbon refrigerant has a smaller saturated water content of the low-pressure gas refrigerant than the high-pressure liquid refrigerant at the compressor outlet, the refrigeration cycle effectively absorbs and removes the water content contained in the desiccant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle using a fluorohydrocarbon type refrigerant as a refrigerant, and in particular, a fluorohydrocarbon type refrigerant having an open type compressor such as a car air conditioner. The present invention relates to a refrigeration cycle using a refrigerant, which facilitates absorption and removal of water content in the refrigeration cycle.

[0002]

2. Description of the Related Art Conventionally, in this type of refrigeration cycle, since CEC12 was used as a working refrigerant, it penetrated into the refrigeration cycle through the compressor shaft seal, rubber material such as O-ring, or flexible rubber hose. It was effective to install a water removal device for removing the above-mentioned water at the outlet of the condenser (refer to Japanese Patent Publication Nos. 56-137062 and 61-168762).

[0003]

However, in a refrigeration cycle using a fluorocarbon refrigerant such as HFC134a as the working refrigerant, this method cannot sufficiently remove the water content, and therefore the refrigeration Corrosion of the metal portion in the cycle due to the water content of the refrigerant, or freezing of the water content in the refrigerant flow rate control means reduces the refrigerant flow rate, resulting in lubrication of the compressor. There was a drawback in that the return of oil was reduced, causing seizure of the compressor.

The reason will be described with reference to FIG. Figure 3
Is the saturated water content with respect to the temperature of the liquid and gas of CFC12 which is a conventional working refrigerant, and HF which is a fluorohydrocarbon-based refrigerant.
The saturated water content with respect to the temperature of the liquid and gas of C134a is shown. In the refrigeration cycle using CFC12, the desiccant is generally installed in the receiver. The reason for this is shown in FIG.
As shown in, the temperature of the liquid refrigerant in the receiver is about 60 ° C, and the temperature of the low-pressure gas refrigerant is about 15 ° C, so the saturated water content of both refrigerants is almost the same. is there.
Therefore, in the CFC12 cycle, the installation position of the desiccant is irrelevant to the saturated water content of the refrigerant, for example, because the pressure loss due to the desiccant is small and it is suitable for storing the desiccant. , A desiccant is installed in the receiver.

However, in the HFC134a, the saturated water content of the low-pressure gas refrigerant is about 1/8, which is smaller than that in the outlet refrigerant of the condenser. In other words, when installing the water removal device on the outlet side of the condenser, it is necessary to install a considerably larger amount of desiccant than in the case of CFC12 which is a conventional working refrigerant, and the conventional equipment is used as it is. It shows that doing is not realistic.

On the other hand, the water contained in the high-pressure liquid refrigerant upstream of the refrigerant flow rate control means is
Adiabatically expands, and when heat is exchanged with air and gasified in the evaporator, the amount of water that can be dissolved in the refrigerant decreases,
Water vapor or water drops. That is, it is shown that the low pressure gas refrigerant contains a very large amount of water vapor.

The present invention makes effective use of the above-mentioned characteristics of a fluorohydrocarbon refrigerant such as HFC134a in a refrigeration cycle in which a fluorohydrocarbon refrigerant is used as a working refrigerant so that the water content in the cycle is effectively reduced. It is intended to be absorbed and removed.

[0008]

The present invention is intended to effectively absorb and remove water content in a refrigeration cycle in a refrigeration cycle using a fluorohydrocarbon refrigerant such as HFC134a. , A compressor, a condenser, a refrigerant flow rate control means, an evaporator and a pipeline connecting them, and in a refrigeration cycle using a fluorohydrocarbon refrigerant as a working refrigerant, absorbing and removing water in the refrigeration cycle Disclosed is a refrigeration cycle in which a water removing device for performing the above operation is provided in a low pressure pipe line extending from an evaporator to a compressor.

The object can be more achieved by using a synthetic oil having oxygen in the molecule as the refrigerating machine oil, and a water detecting means for detecting the amount of water contained in the refrigerating cycle is further provided. Alternatively, it is a very desirable embodiment to configure the moisture removing device so that the desiccant can be exchanged without extracting the refrigerant in the refrigeration cycle.

[0010]

With the above-described structure according to the present invention, the water content in the cycle is effectively absorbed and removed by the water removing device even though the refrigerant is a refrigerating cycle using a fluorohydrocarbon refrigerant. Therefore, it is possible to prevent the metal portion from being corroded by moisture in the refrigeration cycle, or the compressor from being seized due to freezing of the refrigerant flow rate control means.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below based on the description of the embodiments with reference to the drawings. FIG. 1 is a pipeline diagram showing the entire configuration of a refrigeration cycle using a fluorocarbon refrigerant such as HCF134a as a working refrigerant according to the present invention, and FIG.
It is a partial cross section perspective view which shows one Example of the water | moisture content removal apparatus used for the cycle.

As shown in FIG. 1, the refrigeration cycle includes a compressor 1, a condenser 2, a liquid receiver 3, a refrigerant flow rate control means 4, an evaporator 5, a water removing device 6, a high pressure gas pipe 7, and a high pressure liquid pipe. 8, the low-pressure liquid pipe 9 and the low-pressure gas pipe 10, and except the mounting position of the water removing device 6, the structure of the refrigerating cycle itself is almost the same as a conventionally known one, and the detailed description of the refrigerating cycle is omitted. To do. In the present invention, the water removing device 6 is installed in the middle of the low-pressure gas pipe 10. In the following description, the structure different from the conventional one in relation to the configuration and the action and effect accompanying it will be mainly described. explain.

In the water removing device 6, a low-pressure gas pipe 10 is opened in the radial direction on the opening side of a bottomed case 13.
A disc 12 having a large number of openings 11 is installed at the bottom of the low-pressure gas pipe 10, and a desiccant 15 such as a molecular sieve is made of polyester fiber or the like in a space formed by the disc 12 and the case. The bag 16 is stored in a sealed bag 16. The case 13 has a lid 14 to keep the inside and outside of the case airtight. The disc 12 is fixed to the case 13 by brazing or other means so that the position of the disc 12 does not change.
12 or the desiccant does not block the flow of low pressure gas.

Here, the water removing device 6 is connected to the low pressure gas pipe 10
The reason for providing it in the middle of is explained. As described above, in the conventional refrigeration cycle using CFC12 as the working refrigerant, the desiccant is generally installed in the liquid receiver 3. The reason for this is that the temperature of the liquid refrigerant in the receiver 3 is usually about 60 ° C, and the temperature of the low-pressure gas refrigerant is about 15 ° C. Is the same,
Since the installation position of the desiccant is irrelevant to the saturated water content of the refrigerant, for example, the pressure loss due to the desiccant is small, and because it is suitable for storing the desiccant, etc.,
A desiccant is installed in the liquid receiver 3.

However, in the HFC134a, which is one of the fluorohydrocarbon refrigerants, as described above, the low-pressure gas whose temperature is about 15 ° C. is about 15 ° C. as compared with the temperature of the outlet refrigerant of the condenser 2 which is about 60 ° C. As can be seen from Fig. 3, the saturated water content of the refrigerant is about 1/8.
And few. This means that the water contained in the high-pressure liquid refrigerant upstream of the refrigerant flow rate control means 4 expands adiabatically in the refrigerant flow rate control means 4 and exchanges heat with air in the evaporator 5. When gasified, the amount of water that can be dissolved in the refrigerant decreases, resulting in the state of water vapor or water droplets. That is, it is shown that the low pressure gas refrigerant contains a very large amount of water vapor. Therefore, by installing the desiccant in the low-pressure gas refrigerant region, it becomes possible to effectively absorb the water in the refrigerant by the desiccant.

Further, according to the present embodiment, since the desiccant is not installed in the refrigerant passage, it is possible to absorb and remove water in the refrigeration cycle without increasing pressure loss in the low pressure gas passage. There is such an effect. FIG. 4 shows another embodiment of the water removing device. In this embodiment, a resin or metal cylinder 18 having a mesh or a large number of holes is provided in a part of the low-pressure gas pipe 10, and a desiccant 15 enclosed in a bag 16 of, for example, polyester fiber is provided outside the cylinder.
Further, the outside is covered with, for example, a cylindrical case 17, and both ends of the case 17 are joined to the low-pressure gas pipe 10 by a method such as brazing. As a result, the inside and outside of the case are kept airtight. In the present embodiment, the moisture contained in the refrigeration cycle can be absorbed and removed without increasing the pressure loss in the low pressure gas passage, and the moisture removing device can be provided without overhanging the pressure of the low pressure gas pipe larger than the outer diameter. There is.

FIG. 5 shows another embodiment of the water removing device. In a car air conditioner, the intake pressure pulsation of the compressor may vibrate the evaporator, causing noise in the passenger compartment. As a means for avoiding this, the simplest measure is to install a cylindrical silencer in the middle of the low-pressure gas pipe. This example provides a water removal device suitable for a refrigeration cycle having such a silencer. In FIG. 5, a cylindrical silencer 20 is provided in the middle of the low pressure gas pipe 10. The low-pressure gas pipe 10 is joined to one disc portion of the silencer 20, and the low-pressure gas pipe is connected to the other disc portion via a resin or metal cylinder 18 having a mesh shape or a large number of holes. ing. A desiccant 15 enclosed in a bag 16 made of, for example, polyester fiber is installed on the outer side of the cylinder 18. Further, a cylindrical case 22 is installed on the outer side of the case 22. One end of the case 22 is joined to the silencer 21 and the other end is joined to the low-pressure gas pipe 10, so that the inside and outside of the case 22 are kept airtight. There is. With such a structure, the lid of the opening of the case 22 (the opening on the left side of the case in FIG. 5) can be used also as the case 21 of the silencer, so that an inexpensive water removing device can be obtained. There is an effect that you can.

The case of the silencer 20 in this embodiment
By moving the joint between 21 and the case 22 of the water removal device to the low-pressure gas pipe side of the silencer, after assembling the low-pressure gas pipe 10, the case 22, the cylinder 18, and the desiccant 15 on the right side of FIG. 5,
When brazing the case 22 to the case 21 of the muffler 20, it prevents the desiccant 15 or the polyester resin encapsulating it from being deteriorated by heat, and the flux used for brazing enters the refrigeration cycle. By avoiding this, there is also an effect that cleaning of the silencer and the water removing device after brazing can be omitted.

As described above, according to the present invention, since it is not necessary to provide the desiccant in the liquid receiver, it is not necessary to install the liquid receiver in the cycle as an independent device unlike the conventional one. However, it is a preferable aspect to allow the refrigerant to leak from the refrigeration cycle to the atmosphere, and to secure a space for storing the extraly charged refrigerant in the refrigeration cycle.

FIG. 6 is a pipeline diagram showing the entire structure of a refrigeration cycle that can be effectively used for this purpose. That is, here, the condenser 2 is provided with a space 23 for storing the above-mentioned excess refrigerant in a liquid state. FIG. 7 shows one aspect of the structure of the condenser suitable for this embodiment. This condenser is connected to the inlet side header 24 into which the high pressure gas refrigerant flows, this header,
Further, a plurality of condensing pipes 25 provided in a comb shape, the condensing pipes of the respective condensing pipes 25 are connected, and the liquid refrigerant liquefied in each condensing pipe is collected, provided on the outlet side header 27 and each condensing pipe. In order to achieve the object of the present invention, the flow passage area of the outlet header 27 is larger than that used in a refrigeration cycle having a conventional receiver, that is, The internal volume of the header is set large.

By using the condenser having such a structure and having the cycle configuration shown in FIG. 6, the condenser can easily have the capacity of the liquid receiver, and as a result, the liquid receiver can be omitted. Therefore, there is an effect that the refrigeration cycle can be configured at a lower cost. In the embodiments shown in FIGS. 2, 4 and 5, the refrigerating machine oil filled in the refrigerating cycle for the purpose of lubricating the compressor 1 is saturated with the refrigerating machine oil such as ester oil or fluorosilicone oil. It is suitable when the water content is small. The reason for this is that these refrigerating machine oils have a small amount of saturated water, and therefore the amount of water invading from the outside air into the refrigeration cycle is small.
Therefore, the life cycle can be sufficiently satisfied without exchanging the desiccant.

On the other hand, in a refrigeration cycle using, for example, polyalkylene glycol having excellent compatibility with a refrigerant as the refrigerating machine oil, the saturated water content of the refrigerating machine oil exceeds 2 wt%, so that the infiltration moisture from the outside air into the refrigeration cycle is increased. Many. In such a refrigeration cycle, CFC1 is used as a refrigerant.
Attempting to obtain a life cycle equivalent to that with 2, the amount of desiccant required to absorb all the water that enters the refrigeration cycle during this time exceeds 2000 ml. However, as is well known, the engine and a large number of auxiliary devices are housed in the engine room, and it is virtually impossible to install the large-capacity water removal device as described above. Under these circumstances,
In order to absorb and remove water in the refrigeration cycle, it is necessary to replace the desiccant with a new one periodically or as needed.

The structure of a refrigerating cycle suitable for solving such a problem and the water removing device used therefor will be described below. FIG. 8 is a diagram showing an overall configuration of a refrigeration cycle showing an example thereof. An inlet side bypass pipeline 28 and an outlet side bypass pipeline 29 are provided in the middle of the low pressure gas pipe 10 of the refrigeration cycle, and these bypasses are provided. A desiccant is provided between the lines.

FIG. 9 shows a moisture removing device containing the desiccant, which is made of, for example, a case 30 connected to the inlet side bypass conduit 28 and a polyester fiber provided in the case 30. Desiccant 15 enclosed in a bag 16, a lid 40 connected to the outlet side bypass pipe 29, the case
An O-ring 43 provided between the flange 41 formed in the opening of the 30 and the lid 40, and mechanically joining the flange 41 and the lid 40, for example, a joining means such as a bolt (not shown) Composed of.

This water removing device is provided with a water monitoring means 31 for monitoring the amount of water contained in the case refrigerant (or refrigerating machine oil). The water content monitoring means is joined to the outside of the case 30 and is connected to the inside of the case 42. The housing 42 is installed in the housing and changes color depending on the amount of water, for example, cobalt chloride or anhydrous copper sulfate in a sheet form. An appropriate moisture content detecting means such as a moisture sensitive member 32 molded or coated with a transparent material, for example, a transparent member 33 made of hard glass or polycarbonate, and fixing the transparent member 33 to the housing C It is composed of a fixing member 34 such as a ring, a transparent member 33, and a sealing means 35 such as an O-ring which is installed between the transparent member 33 and the housing 42 and prevents the refrigerant from leaking from the moisture monitoring means.

Further, the water removing means has a check valve 36.
Is provided, and the inside and outside of the case communicate with each other only when the pin 59 of the valve is pushed from the outside. Further, joint means 37 and 38 are provided in the middle of the pipelines of the inlet-side bypass pipeline 28 and the outlet-side bypass pipeline 29, respectively.
The function of being able to remove from the water removing device, the function of preventing the refrigerant from leaking from the low-pressure gas pipe 10 through the bypass lines 28 and 29 at the same time as removing the water removing device, and the water removing device to the refrigeration cycle. At the same time as being removed from the device, it has a function of preventing the refrigerant in the water removing means from leaking to the outside of the apparatus via the bypass pipe lines 28 and 29, and a conventionally known joint means is used. .. Further, although the inlet side bypass pipeline 28 is directly opened to the pipe wall of the low pressure gas pipeline 10, the wake side opening end of the outlet side bypass pipeline 29 is at the center of the low pressure gas pipeline 10 It opens toward the downstream side with respect to the flow of the refrigerant in the gas pipe. In addition, the flow-side open end is shaped so that its flow path is gradually narrowed, and has a so-called diffuser structure. Since the water removing means has the above structure, it is possible to give a positive flow of the refrigerant to the water removing device.

In using this device, looking inside through the sight glass of the moisture monitoring means attached to the moisture removing device,
If the color of the moisture responsive means is discolored, first remove the water removal device from the refrigeration cycle using the coupling means 37, 38 installed in the bypass lines 28, 29 and check valve.
The pin 59 of 36 is pressed to release the gas in the case 30, the lid 40 is removed, and the desiccant in the form of a pack in the case 30 is removed. Then, refill with a new desiccant, close the lid, evacuate the inside of the case using a check valve, and preferably pressurize the inside of the case with a refrigerant, and then use the joint means 37, 38 to remove moisture. Attach the removal device to the refrigeration cycle. By doing so, it is possible to replace with a new desiccant without releasing the refrigerant in the refrigeration cycle.

In the above description, the water removing device is used in the refrigerating cycle in which the condenser 23 is provided with the space 23 for storing the liquid refrigerant. It will be easily understood that the use of is not limited to that, and can be applied to a refrigeration cycle using the liquid receiver 3 as shown in FIG. 1, for example.

Further, in the present embodiment, the outlet side open end of the outlet side bypass pipe 29 of the water removing device has a diffuser structure, but the low pressure gas pipe opening of the inlet side bypass pipe and the outlet side bypass pipe are When there is a resistance such as a bend that obstructs the flow of the refrigerant in the low pressure gas pipe between the portion passing through the low pressure gas pipe, the outlet side bypass pipe line 29 is simply Sufficient flow of the refrigerant can be given to the water removing device simply by opening the pipe 10.
It will also be appreciated that in such cases it is not necessary to use the diffuser structure as described above.

Next, the concept of the flow rate of the refrigerant required for removing water in this embodiment will be described. It is empirically known that the amount of water infiltrating into the refrigeration cycle from the flexible rubber hoses used for the high-pressure gas piping and the low-pressure gas piping, the compressor shaft seal, the O-ring, etc. is about 2 to 3 g per year. Has been. On the other hand, the operating time of the refrigeration cycle can be estimated to be about 600 hours per year. The refrigerant circulates once in the refrigeration cycle in about 20 to 40 seconds, and therefore circulates 72000 times at 600 hours. Even if the water removal device is supplied with 1% of the total refrigerant flow rate, all the refrigerant passes through the desiccant 720 times. Therefore, it is understood that it is not necessary to immediately absorb and remove the moisture that has permeated from the rubber material by drying, and it is sufficient to absorb moisture gradually during the refrigeration cycle operation.

FIG. 10 shows still another embodiment of the water removing apparatus used in the present invention. The opening 44 provided in the low-pressure gas pipe 10 is provided so as to cover the opening 44 and only the water is selectively permeated. A moisture permeable membrane 46 made of, for example, a polyamide resin, provided to allow the moisture permeable membrane to withstand the pressure difference between the refrigerant pressure and the atmospheric pressure in the refrigeration cycle, and the moisture that has permeated the permeable membrane. Reinforcement member 47 having a large number of holes to allow passage of the water, the ring for installing so as to press the periphery of the moisture permeable membrane 46 and the reinforcement member 47 to the flange 50 provided around the opening of the low-pressure gas pipe 10. Member
45, a fixing member (not shown) such as a screw for fixing the ring-shaped member to the flange 50,
A bottomed case 49 fixed to a screw provided on the outer peripheral portion of the ring-shaped member 45 and between the disk surface of the ring-shaped member 45 and the case to prevent refrigerant leakage between the two members. An O-ring 48 for the purpose and a desiccant 15 placed in the case and enclosed in a bag 16 made of, for example, polyester fiber.

In this water removing device, the water permeable film 46 does not allow the refrigerant to permeate therethrough, so that the case 49 can be simply removed from the ring member 45 without leaking the refrigerant from the refrigeration cycle.
Moreover, there is an effect that the desiccant can be easily replaced. FIG. 11 shows still another embodiment of the water removing device used in the present invention, and FIG. 12 shows a cross section taken along the line II of FIG. The moisture removing device of this embodiment is located in the middle of the low pressure gas pipe, for example, a moisture permeable membrane 52 made of polyamide resin or the like,
And a reinforcing member 53 for the moisture permeable membrane having a large number of holes provided on the outer periphery thereof are simultaneously crimped to the outer peripheral portion of the low pressure gas pipe by, for example, a caulking member 51. Further, cases 54 and 55 each having one end closed to the low-pressure gas pipe by brazing, for example, are provided on the outer peripheral portion, and the openings of the cases are joined by means such as brazing. A connector 58, which is sealed with a flare nut 57 on the outer periphery of either of the cases 54 and 55, has a check valve 3 having the same structure as that shown in FIG.
6. The moisture monitoring means 31 and the relief valve 56 which is opened when the pressure inside the case exceeds 2 kg / cm @ 2 due to slight leakage of the refrigerant are installed. Further, a desiccant which can be handled as a liquid having a high hygroscopic property such as polyalkylene glycol or a fluid such as a powdered molecular sieve is enclosed between the case and the water permeable membrane.

In the moisture removing device of this embodiment, when the moisture monitoring means is viewed from the outside and the flare nut 57 is removed when the color changes, the check valve 36 does not leak the refrigerant in the refrigeration cycle, The desiccant (hygroscopic agent) can be easily extracted, and a new desiccant can be easily enclosed from the connector 58.

It should be noted that the drying agent should be replaced every two years, for example.
If the amount of desiccant enclosed is set so that the temperature is good, or if the moisture monitoring means is set at any position of the refrigeration cycle, the moisture monitoring means installed in the moisture removing device is not always necessary. It will be easily understood that the check valve 56 is not necessary if the pressure-resistant strength of the cases 54 and 55 is sufficient.

In this embodiment, an example of using polyalkylene glycol as a desiccant (hygroscopic agent) is shown. The general formula is R ₁ O (CH ₂ —CH ₂ O) n (CH ₂ —CHCH ₃ O) mCR ₂ Indicated by. Among these, as the number of n increases with respect to m, the saturated water content increases and more water can be absorbed. However, the moisture in the refrigeration cycle is absorbed and removed by the desiccant only when the partial pressure of the moisture in the refrigerant and the refrigerating machine oil in the refrigeration cycle is higher than the partial pressure of the moisture in the desiccant. In this sense, the molecular structure of the polyalkylene glycol to be selected as the desiccant (hygroscopic agent) is determined by the types of the refrigerant and the refrigerating machine oil.

Although the low-pressure gas pipe 10 is installed in the water removing device in the above-described embodiments, the installation position of the water removing device is not limited as long as it is a region where substantially low-pressure gas exists, that is, a low-pressure pipe line region. That is, the water removing device may be integrated with the evaporator 5 and housed in the case of the evaporator.

[0037]

As described above, according to the present invention, HFC1
Since the water contained in the refrigeration cycle using a fluorocarbon refrigerant such as 34a can be effectively absorbed and removed by the water removal device, the metal parts in the refrigeration cycle can be corroded or the refrigerant flow control means This has the effect of avoiding the seizure of the compressor due to freezing.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a refrigeration cycle showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional perspective view of an embodiment of a moisture removing device suitable for the present invention.

FIG. 3 is a graph showing a correlation between refrigerant temperature and saturated water content.

FIG. 4 is a cross-sectional view showing another embodiment of the moisture removing apparatus suitable for the present invention.

FIG. 5 is a cross-sectional view showing still another embodiment of the moisture removing device.

FIG. 6 is an overall configuration diagram showing another embodiment of the refrigeration cycle of the present invention.

FIG. 7 is a structural diagram of a condenser suitable for the refrigeration cycle of FIG.

FIG. 8 is an overall configuration diagram showing still another embodiment of the refrigeration cycle of the present invention.

9 is a diagram showing a water removal device suitable for the refrigeration cycle of FIG.

FIG. 10 is a diagram showing another embodiment of the water removal apparatus suitable for the refrigeration cycle of FIG. 8.

FIG. 11 is a diagram showing still another embodiment of the moisture removing device suitable for the refrigeration cycle of FIG. 8.

12 is a view showing a cross section taken along line I-I of FIG. 11.

[Explanation of symbols]

1 Compressor, 2 Condenser, 4 Refrigerant flow control means, 5 Evaporator, 6 Moisture removing device, 7 High pressure gas pipe, 8 High pressure liquid pipe, 9 Low pressure liquid pipe 10 Low pressure gas pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Machimura, Inventor Hideki Machimura, Katsuta City, Ibaraki 2520 Takaba, Automotive Equipment Division, Hitachi, Ltd. Inside Hitachi Research Laboratory

Claims (4)

[Claims] 1. A refrigeration cycle comprising a compressor, a condenser, a refrigerant flow rate control means, an evaporator and a pipeline connecting these, and using a fluorohydrocarbon refrigerant as a working refrigerant, the refrigeration cycle A refrigeration cycle characterized in that a moisture removing device for absorbing and removing moisture therein is provided in a low-pressure pipe line from the evaporator to the compressor. 2. A compressor, a condenser, a refrigerant flow rate control means, an evaporator and a pipe line connecting them, and a fluorohydrocarbon refrigerant is used as a working refrigerant. A refrigeration cycle using a synthetic oil containing oxygen, wherein a water removal device for absorbing and removing water in the refrigeration cycle is provided in a low pressure pipe line from the evaporator to the compressor. 3. A water content detecting means for detecting the water content of the refrigeration cycle.
Alternatively, the refrigeration cycle described in 2. 4. The refrigerating cycle according to claim 1, wherein the water removing device has a structure capable of exchanging the desiccant without extracting the refrigerant in the refrigerating cycle.