CN101878402A - Refrigeration device - Google Patents

Abstract

An air conditioner (1) using carbon dioxide as the refrigerant has a two-stage compression type compression mechanism (2), a heat source-side heat exchanger (4), an expansion mechanism (5), a utilization-side heat exchanger (6), an intermediate cooler (7) arranged in an intermediate refrigerant tube (8) for causing a refrigerant discharged from a front-stage compression element to be sucked by a rear-stage compression element and functioning as a cooler for the refrigerant discharged from the front-stage compression element and sucked into the rear-stage compression element, and an intermediate oil separation mechanism (16) arranged at a portion between the front-stage compression element of the intermediate refrigerant tube (8) and the entrance of the intermediate cooler (7), and separating refrigeration machine oil entrained in the refrigerant discharged from the front-stage compression element and returning the separated oil to the suction side of the compression mechanism (2).

Description

Refrigerating plant

Technical field

The present invention relates to a kind of refrigerating plant, particularly relate to multi-stage compression formula freeze cycle is carried out in a kind of use at the cold-producing medium of supercritical region work refrigerating plant.

Background technology

As using the cold-producing medium of working to carry out a routine refrigerating plant of multi-stage compression formula freeze cycle, there is the aircondition shown in the patent documentation 1 in past in supercritical region, it uses carbon dioxide to carry out two stage compression type freeze cycle as cold-producing medium.This aircondition mainly has: have the compressor of two compression member that are connected in series, as outdoor heat converter, expansion valve and the indoor heat converter of heat source side heat exchanger.

Patent documentation 1: TOHKEMY 2007-232263 communique

Summary of the invention

The refrigerating plant that the 1st invention relates to, it is to use the refrigerating plant at the cold-producing medium of supercritical region work, and it comprises: compressing mechanism; The heat source side heat exchanger; The expansion mechanism that cold-producing medium is reduced pressure; Utilize square heat-exchanger; Intercooler; And the middle oil content structure of disembarking.Compressing mechanism has a plurality of compression member, and uses the rear section side compression member to compress leading portion side pressure from a plurality of compression member cold-producing medium that parts discharge that contracts successively.Said herein " compressing mechanism " is meant, by connecting the compressing mechanism that multiple compressors forms, compressor comprises the assembled all-in-one-piece compressor of a plurality of compression member and assembling single compressed parts and the compressor that constitutes and/or assemble a plurality of compression member and the compressor that constitutes.In addition, " compress leading portion side pressure from a plurality of compression member cold-producing medium that parts discharge that contracts successively " and be not and only refer to two compression member that " leading portion side pressure contract parts " and " rear section side compression member " is connected in series with the rear section side compression member, and be meant that a plurality of compression member are connected in series, and the relation between each compression member has the relation of above-mentioned " leading portion side pressure contract parts " and " rear section side compression member ".Intercooler is set to be used for making from contract cold-producing medium that parts discharge of leading portion side pressure and sucks in the intermediate refrigerant pipe the rear section side compression member and can discharge the cooler that be inhaled into the cold-producing medium the rear section side compression member then as the parts that contract from the leading portion side pressure.The leading portion side pressure that middle oil eliminator is set at the intermediate refrigerant pipe contract parts with the inlet of intercooler between part and will from cold-producing medium, separate and make it return described compressing mechanism then from the contract refrigerator oil of parts discharge of leading portion side pressure with cold-producing medium.

In traditional aircondition, and under adopting with the situation of air as the heat exchanger of thermal source as outdoor heat converter, the critical-temperature (about 31 ℃) of the carbon dioxide that uses as cold-producing medium with as can be identical as the temperature of the air of the outdoor heat converter thermal source of the cooler of cold-producing medium, compare with cold-producing mediums such as R410A with R22, its temperature is lower, therefore, when the cooling operation that turns round as cooling, in order to make the air in the heat exchanger can the cooling refrigeration agent, under the high state of the critical pressure of the high pressure ratio cold-producing medium of freeze cycle, turn round.So, the temperature of the cold-producing medium of discharging from the rear section side compression member of compressor raises, therefore, in the outdoor heat converter of the cooler that can be used as cold-producing medium, the air and the temperature difference between the cold-producing medium as thermal source increase, radiation loss in the outdoor heat converter increases, and therefore, is difficult to obtain the such problem of high running efficiency with regard to existence.

In order to address this problem, in this refrigerating plant, in the intermediate refrigerant pipe the cold-producing medium suction rear section side compression member that is used for the parts that contract from the leading portion side pressure are discharged the intercooler that can discharge the cooler that be inhaled into the cold-producing medium the rear section side compression member then as the parts that contract from the leading portion side pressure is set, reduce the temperature that is inhaled into the cold-producing medium in the rear section side compression member with this, so, the temperature of the cold-producing medium of discharging from the rear section side compression member of compressor is descended, reduce the radiation loss in the outdoor heat converter.

Herein, owing to the refrigerator oil that is mixed with the cold-producing medium of discharging at the parts that contract from the leading portion side pressure of compressor in the compressor, therefore, the refrigerator oil in the compressor is just gone out outside the compressor by the intermediate refrigerant pipe racks.As mentioned above, if intercooler only is set, so, refrigerator oil will accumulate in the intercooler and can't return compressor, and therefore, the machine oil that might produce compressor exhausts.

But, the oil content structure of disembarking in the middle of being provided with in this refrigerating plant can stop the refrigerator oil that contracts the cold-producing medium that parts discharge from the leading portion side pressure to flow into intercooler, therefore, can prevent that refrigerator oil from accumulating in the intercooler, prevent that the machine oil of compressing mechanism from exhausting.In addition, not only can prevent that the heat transfer property that accumulates in the intercooler that causes in the intercooler because of refrigerator oil from descending and pressure loss increase, and can improve the performance of refrigerating plant.

If particularly compressing mechanism is included in the high pressure dome-shaped compressor of taking in a plurality of compression member of being connected in the identical casing, so, behind the space that refrigerator oil accumulated of cold-producing medium in being discharged to casing that the rear section side compression member is discharged, be discharged to outside the casing, therefore, the oil mass of the refrigerator oil that is discharged from cold-producing medium is few, on the contrary, the cold-producing medium of discharging owing to the parts that contract from the leading portion side pressure directly is expelled to outside the casing, therefore, the oil mass of the refrigerator oil that is discharged from cold-producing medium is many, and the oil mass that accumulates in the refrigerator oil in the intercooler might increase, therefore, it is very effective middle oil content among the present invention structure of disembarking to be set.

The 2nd refrigerating plant that relates to of invention, in the refrigerating plant that the 1st invention relates to, the middle oil content structure of disembarking has: will be with cold-producing medium from the leading portion side pressure middle oil eliminator that refrigerator oil that parts discharge separates from cold-producing medium that contracts; Be connected with middle oil eliminator and be used for making the refrigerator oil of from cold-producing medium, separating to return the middle oil return pipe of compressing mechanism.

In this refrigerating plant, with middle oil eliminator be arranged on the leading portion side pressure contract parts near, so just can the leading portion side pressure contract parts near the separation refrigerator oil, therefore, can prevent that refrigerator oil from accumulating in the intercooler and the intermediate refrigerant pipe in.

The 3rd refrigerating plant that relates to of invention, in the refrigerating plant of the 1st invention, the middle oil content structure of disembarking has: the header box that is provided with at the inlet of intercooler; Be used for connecting the lower end of header box and the middle oil return pipe of compressing mechanism.

In this refrigerating plant, owing to have the function of oil eliminator at the header box of the inlet setting of intercooler, therefore, increase that can control instrument quantity.

The 4th refrigerating plant that relates to of invention in the 1st～the 3rd invention in any refrigerating plant that relates to, is a carbon dioxide at the cold-producing medium of supercritical region work.

Description of drawings

Fig. 1 is the structure sketch plan as the aircondition of an embodiment of the refrigerating plant that the present invention relates to.

The pressure of the freeze cycle when Fig. 2 is cooling operation-enthalpy line chart.

The temperature of the freeze cycle when Fig. 3 is cooling operation-entropy line chart.

Fig. 4 is the disembark structure sketch plan of structure of intercooler in the aircondition that relates to of variation 1 and middle oil content.

Fig. 5 is the structure sketch plan of the aircondition that relates to of variation 2.

Fig. 6 is the structure sketch plan of the aircondition that relates to of variation 3.

Fig. 7 is the structure sketch plan of the aircondition that relates to of variation 3.

Fig. 8 is the structure sketch plan of the aircondition that relates to of variation 3

Pressure-enthalpy the line chart of freeze cycle when Fig. 9 is the cooling operation of the aircondition that relates to of variation 3.

Temperature-entropy the line chart of freeze cycle when Figure 10 is the cooling operation of the aircondition that relates to of variation 3.

Figure 11 is the structure sketch plan of the aircondition that relates to of variation 4.

Figure 12 is the structure sketch plan of the aircondition that relates to of variation 5.

Figure 13 is the structure sketch plan of the aircondition that relates to of variation 5.

Figure 14 is the structure sketch plan of the aircondition that relates to of variation 6.

Pressure-enthalpy the line chart of freeze cycle when Figure 15 is the cooling operation of the aircondition that relates to of variation 6.

Temperature-entropy the line chart of freeze cycle when Figure 16 is the cooling operation of the aircondition that relates to of variation 6.

Figure 17 be the aircondition that relates to of variation 6 heat running the time freeze cycle pressure-enthalpy line chart.

Figure 18 be the aircondition that relates to of variation 6 heat running the time freeze cycle temperature-entropy line chart.

Figure 19 is the structure sketch plan of the aircondition that relates to of variation 6.

Figure 20 is the structure sketch plan of the aircondition that relates to of variation 7.

Figure 21 is the structure sketch plan of the aircondition that relates to of variation 7.

Symbol description

1, aircondition (refrigerating plant)

2,102,202, compressing mechanism

4, the heat source side heat exchanger

5, expansion mechanism

6, utilize square heat-exchanger

7, intercooler

8, the intermediate refrigerant pipe

16, the middle oil content structure of disembarking

16a, middle oil eliminator

16b, middle oil return pipe

16d, header box

The specific embodiment

Below, with reference to the accompanying drawings, the embodiment of the refrigerating plant that the present invention relates to is described.

(1) structure of aircondition

Fig. 1 is the structure sketch plan as the aircondition 1 of an embodiment of the refrigerating plant that the present invention relates to.Aircondition 1 has the refrigerant line 10 that can carry out cooling operation, and it uses at the cold-producing medium of supercritical region work (being carbon dioxide herein) and carries out two stage compression type freeze cycle.

The refrigerant line 10 of aircondition 1 mainly comprises: compressing mechanism 2, heat source side heat exchanger 4, expansion mechanism 5, utilize square heat-exchanger 6 and intercooler 7.

In the present embodiment, compressing mechanism 2 constitutes by using two compression member that cold-producing medium is carried out secondary compressor for compressing 21.Compressor 21 adopts a kind of closed structure that holds drive motor for compressor 21b, driving shaft 21c and compression member 2c, 2d in casing 21a.Drive motor for compressor 21b and driving shaft 21c link.This driving shaft 21c and two compression member 2c, 2d link.That is, compressor 21 adopts an a kind of so-called secondary compressed configuration: two compression member 2c, 2d and a driving shaft 21c link, and two compression member 2c, 2d are all driven by compressor drive motors 21b rotation.In the present embodiment, compression member 2c, 2d are rotary or the positive displacement compression member of vortex etc.Compressor 21 sucks cold-producing medium from suction line 2a, utilize compression member 2d to compress the cold-producing medium that this is inhaled into, discharge to intermediate refrigerant pipe 8 then, the cold-producing medium that is discharged to intermediate refrigerant pipe 8 is sucked further compressed refrigerant among the compression member 2d, discharge to discharge pipe 2b then.Herein, intermediate refrigerant pipe 8 is the refrigerant pipes the compression member 2d that cold-producing medium sucks with the rear section side of compression member 2c is connected that is used for discharging from the compression member 2c that is connected with the leading portion side of compression member 2c.In addition, discharge pipe 2b is used for being sent to the refrigerant pipe of heat source side heat exchanger 4 from the cold-producing medium that compressing mechanism 2 is discharged, and oil content disembark structure 41 and unidirectional mechanism 42 are set in discharge pipe 2b.The oil content structure 41 of disembarking is used for the refrigerator oil of discharging from compressing mechanism 2 with cold-producing medium separated from cold-producing medium and makes its suction of returning compressing mechanism 2 one side then, and it mainly comprises: the oil eliminator 41a that will separate from cold-producing medium with the refrigerator oil that cold-producing medium is discharged from compressing mechanism 2, be connected with oil eliminator 41a and make refrigerator oil separated from cold-producing medium return the oil return pipe 41b of the suction line 2a of compressing mechanism 2.The mechanism of decompressor 41c that refrigerator oil to the oil return pipe 41b that flows through reduces pressure is set in oil return pipe 41b.In the present embodiment, mechanism of decompressor 41c uses capillary.Unidirectional mechanism 42 is used for allowing the discharge one effluent heat source end heat exchanger 4 of cold-producing medium from compressing mechanism 2, and is used for block refrigerant and flows to discharge one side of compressing mechanism 2 from heat source side heat exchanger 4, uses check valve in the present embodiment.

In the present embodiment, compressing mechanism 2 has two compression member 2c, 2d, compresses leading portion side pressure from these compression member 2c, the 2d cold-producing medium that parts discharge that contracts in the rear section side compression member successively.

Heat source side heat exchanger 4 is the heat exchangers that can be used as the cooler of cold-producing medium.One end of heat source side heat exchanger 4 is connected with compressing mechanism 2, and the other end is connected with expansion mechanism 5.In addition, not expression among the figure herein, the water and air that carries out the cooling source of heat exchange as the cold-producing medium with the heat source side heat exchanger 4 of flowing through is supplied to heat source side heat exchanger 4

Expansion mechanism 5 is used for electric expansion valve is used in the cold-producing medium decompression in the present embodiment.One end of expansion mechanism 5 is connected with heat source side heat exchanger 4, and the other end is connected with utilizing square heat-exchanger 6.In addition, in the present embodiment, the high-pressure refrigerant that will be cooled in heat source side heat exchanger 4 is sent to and utilizes before the square heat-exchanger 6, and expansion mechanism 5 reduces pressure to it.

Utilizing square heat-exchanger 6 is the heat exchangers that can be used as the heater of cold-producing medium.Utilize an end of square heat-exchanger 6 to be connected with expansion mechanism 5, the other end is connected with compressing mechanism 2.In addition, expression among the figure herein is supplied to as the water and air that carries out the heating source of heat exchange with the cold-producing medium that utilizes square heat-exchanger 6 of flowing through and utilizes square heat-exchanger 6.

Intercooler 7 is set in the intermediate refrigerant pipe 8, and it is the heat exchanger that can discharge the cooler that is inhaled into the cold-producing medium the compression member 2d then as the parts 2c that contracts from the leading portion side pressure.In addition, not expression among the figure herein, the water and air that carries out the cooling source of heat exchange as the cold-producing medium with the intercooler 7 of flowing through is supplied to intercooler 7.So intercooler 7 is not the cold-producing medium that use circulates in refrigerant line 10, in this, it is the cooler that can use external heat source.

In addition, the leading portion side pressure of intermediate refrigerant pipe 8 contract part between the inlet of parts 2c and intercooler 7 be provided with in the middle of the oil content structure 16 of disembarking.Disembark refrigerator oil the cold-producing medium that structure 16 is used for the parts 2c that contracts from the leading portion side pressure is discharged of middle oil content is separated from cold-producing medium and is made it return compressing mechanism 2 then.The middle oil content structure 16 of disembarking mainly comprises: will be from the leading portion side pressure middle oil eliminator 16a that refrigerator oil the cold-producing medium that parts 2c discharges separates from cold-producing medium that contracts; Be connected with middle oil eliminator 16a and be used for making the refrigerator oil of from cold-producing medium, separating to return the middle oil return pipe 16b of compressing mechanism 2.In the present embodiment, in the middle of middle oil return pipe 16b connects between suction one side (be suction line 2a) of the oil export of oil eliminator 16a and compressing mechanism 2, and be provided with the mechanism of decompressor 16c that the refrigerator oil to the centre oil return pipe 16b that flows through reduces pressure herein.In the present embodiment, mechanism of decompressor 16c uses capillary.

Expression herein, aircondition 1 also have and are used for controlling the control part of operation that compressing mechanism 2, expansion mechanism 5 etc. constitute the various piece of airconditions 1.

(2) operation of aircondition

Below, use Fig. 1～Fig. 3, the operation of the aircondition 1 of present embodiment is described.Herein, the pressure of the freeze cycle when Fig. 2 is cooling operation-enthalpy line chart, the temperature of the freeze cycle when Fig. 3 is cooling operation-entropy line chart.In addition, the control of the running in the following cooling operation is undertaken by above-mentioned control part (not shown).In addition, in the following description, high pressure in " high pressure " expression freeze cycle (promptly, some D among Fig. 2,3, the pressure among D ', the E), low pressure in " low pressure " expression freeze cycle (promptly, pressure among some A, the F among Fig. 2,3), middle press (that is the pressure among some B1, the C1 among Fig. 2,3) in " the middle pressure " expression freeze cycle.

If drive compression mechanism 2, so, low pressure refrigerant (with reference to the some A among Fig. 1～Fig. 3) is inhaled into the compressing mechanism 2, at first from suction line 2a, be compressed after parts 2c is compressed to intermediate pressure, be discharged to intermediate refrigerant pipe 8 (with reference to the some B1 among Fig. 1～Fig. 3).During oil content was disembarked the middle oil eliminator 16a of structure 16 in the middle of the compacting cryogen flow into to constitute in the middle of being discharged from, after the refrigerator oil of Liu Ruing is separated with it, be sent to intercooler 7 from parts 2c is contracted in this leading portion side pressure.In addition, oil content was disembarked among the middle oil return pipe 16b of structure 16 in the middle of the refrigerator oil that is separated from centre compacting cryogen in middle oil eliminator 16a flowed into and constitutes, return compressing mechanism 2 (being suction line 2a) herein after the mechanism of decompressor 16c decompression in the middle of being arranged among the oil return pipe 16b, sucked once more in the compressing mechanism 2.Then, in middle oil content is disembarked structure 16 refrigerator oil by compacting cryogen in the middle of after wherein separate, thereby in intercooler 7 with carry out heat exchange be cooled (with reference to the some C1 among Fig. 1～Fig. 3) as the water of cooling source or air.Then, the cold-producing medium that is cooled in this intercooler 7 is inhaled among the compression member 2d that is connected with the rear section side of compression member 2c, is further compressed then, is discharged to discharge pipe 2b (with reference to the some D Fig. 1～Fig. 3) from compressing mechanism 2.Herein, the high-pressure refrigerant that is discharged from from compressing mechanism 2 is according to the secondary squeeze operation of compression member 2c, 2d, is compressed the pressure that becomes above critical pressure (that is the critical pressure Pcp among the critical point CP shown in Figure 2).Then, the high-pressure refrigerant that is discharged from from this compressing mechanism 2 flows into and constitutes oil content and disembark among the oil eliminator 41a of structure 41, and the refrigerator oil of Liu Ruing is separated with it.In addition, the refrigerator oil that is separated from high-pressure refrigerant in oil eliminator 41a flows into and constitutes oil content and disembark among the oil return pipe 41b of structure 41, be arranged on the suction line 2a that returns compressing mechanism 2 after the mechanism of decompressor 41c decompression among the oil return pipe 41b, sucked once more in the compressing mechanism 2.Then, in oil content is disembarked structure 41 refrigerator oil by after the unidirectional mechanism 42, being sent to can be as the heat source side heat exchanger 4 of the cooler of cold-producing medium by the high-pressure refrigerant after wherein separate.The high-pressure refrigerant that is sent to heat source side heat exchanger 4 carries out heat exchange with water or air as cooling source in heat source side heat exchanger 4, thereby is cooled (with reference to the some E among Fig. 1～Fig. 3).The high-pressure refrigerant that is cooled in heat source side heat exchanger 4 is inflated the cold-producing medium that becomes the gas-liquid two-phase state of low pressure after mechanism 5 decompression, be sent to can be as the heater of cold-producing medium utilize square heat-exchanger 6 (with reference to the some F among Fig. 1～Fig. 3).Then, the cold-producing medium of gas-liquid two-phase state that is sent to the low pressure of utilizing square heat-exchanger 6 carries out being heated after the heat exchange evaporation (with reference to the some A among Fig. 1～Fig. 3) then with water or air as heating source in utilizing square heat-exchanger 6.Utilize at this that heated low pressure refrigerant is sucked in the compressing mechanism 2 once more in square heat-exchanger 6.Adopt aforesaid way to carry out cooling operation.

So, because in aircondition 1, in the intermediate refrigerant pipe 8 that is used for making the cold-producing medium suction compression member 2d that from compression member 2c, discharges, intercooler 7 is set, therefore, with the situation that intercooler 7 is not set (in the case, at Fig. 2, among Fig. 3, order according to an an an an an A → B1 → D ' → E → F is carried out freeze cycle) compare, the temperature that is inhaled into the cold-producing medium among the compression member 2d of rear section side of compression member 2c descends (with reference to the some B1 among Fig. 3, C1), the temperature of the cold-producing medium of discharging from compression member 2d also can descend (with reference to the some D among Fig. 3, D ').Therefore, in this aircondition 1, in the heat source side heat exchanger 4 of the cooler that can be used as high-pressure refrigerant, compare with the situation that intercooler 7 is not set, can dwindle the temperature difference as water or the air and the cold-producing medium of cooling source, the radiation loss of the area size that the some B1, D ', D, the C1 that are equivalent to link among Fig. 3 constituted can be further reduced, therefore running efficiency can be further improved.

In addition, because in aircondition 1, after being used for the refrigerator oil of discharging with cold-producing medium separated, part setting between the inlet of the compression member 2c of the leading portion side of intermediate refrigerant pipe 8 and intercooler 7 makes its middle oil content that returns compressing mechanism 2 structure 16 of disembarking from cold-producing medium from parts 2c is contracted in the leading portion side pressure, therefore, with be not provided with in the middle of the disembark situation of structure 16 of oil content compare, the refrigerator oil that can suppress to discharge from parts 2c is contracted in the leading portion side pressure with cold-producing medium flows in the intercooler 7, and can prevent that refrigerator oil from accumulating in the intercooler 7, prevent that the machine oil of compressing mechanism 2 from exhausting.

In addition, oil content is not disembarked under the situation of structure 16 in the middle of be provided with, because of refrigerator oil accumulates in the intercooler 7, cause the heat transfer property of intercooler 7 to descend, heat-shift in the intercooler 7 (promptly, Fig. 2 mid point B1, enthalpy difference between C1) reduces, therefore, might can't reduce the radiation loss in the heat source side heat exchanger 4, and, because of refrigerator oil accumulates in the intercooler 7, cause the pressure loss of intercooler 7 to increase, the pressure (that is the some C1 among Fig. 2) that is inhaled into the cold-producing medium of rear section side compression member 2d reduces, the consumption of power of rear section side compression member 2d might increase, but, because the oil content structure 16 of disembarking in the middle of being provided with, therefore, can prevent that the heat transfer property that accumulates in the intercooler 7 that causes in the intercooler 7 because of refrigerator oil from descending and pressure loss increase, and can improve the performance of aircondition 1.

Structure 16 has because middle the oil content in the present embodiment is disembarked: will be from the leading portion side pressure middle oil eliminator 16a that refrigerator oil the cold-producing medium of parts 2c discharge separates from cold-producing medium that contracts; Be connected with middle oil eliminator 16a and be used for making the refrigerator oil of from cold-producing medium, separating to return the middle oil return pipe 16b of compressing mechanism 2, therefore, with middle oil eliminator 16a be arranged on the leading portion side pressure contract parts 2c near, so just can the leading portion side pressure contract parts 2c near refrigerator oil is separated from cold-producing medium, prevent that refrigerator oil from accumulating in intercooler 7 and the intermediate refrigerant pipe 8.

In addition, as the compressor 21 that constitutes compressing mechanism 2, employing is inhaled into the contract cold-producing medium of parts 2c of leading portion side pressure and is full of the low pressure dome-shaped in the space that refrigerator oil accumulated in the casing 21a, from the leading portion side pressure contract cold-producing medium that parts 2c discharges be full of space in the casing 21a that refrigerator oil accumulates in the middle of press dome-shaped, the cold-producing medium of discharging from rear section side compression member 2c is full of under any one the situation the high pressure dome-shaped in the space in the casing 21a that refrigerator oil accumulates, by the structure 16 of disembarking of oil content in the middle of being provided with, can obtain also to prevent that the machine oil of compressing mechanism 2 from exhausting the equivalence fruit, particularly under the situation of the compressor that adopts the high pressure dome-shaped as the compressor 21 that constitutes compressing mechanism 2, after the cold-producing medium of discharging from rear section side compression member 2d is discharged to space in the casing 21a that refrigerator oil accumulates, be discharged to outside the casing 21a, therefore, the oil mass of the refrigerator oil in the cold-producing medium is few, and directly be expelled to outside the casing 21a from the leading portion side pressure cold-producing medium that parts 2c discharges that contracts, therefore, the oil mass of the refrigerator oil in the cold-producing medium is many, the oil mass that accumulates in the refrigerator oil in the intercooler 7 might increase, therefore, be provided with in the middle of the oil content structure 16 of disembarking very effective.

(3) variation 1

In the above-described embodiment, disembark oil 16 of middle oil content is made of middle oil eliminator 16a and middle oil return pipe 16b, as shown in Figure 4, the middle oil content structure 16 of disembarking also can adopt the structure of oil return pipe 16b in the middle of the lower end of the header box 16d that the inlet of intercooler 7 is provided with connects., adopting intercooler 7 to have under the situation of structure of a plurality of heat transfer streams herein, header box 16d is arranged on intermediate refrigerant pipe 8 and makes duct member between its branched pipe that is divided into each heat transfer stream.In addition, be not connected with the oil export of middle oil eliminator 16a but except the lower end of header box 16b is connected this point, the structure of the middle oil return pipe 16b in middle oil return pipe 16b and the above-mentioned embodiment is identical.

In the structure of this variation 1, have function at the header box 16d of the inlet setting of intercooler 7 as oil eliminator, therefore, compare increase that can control instrument quantity with above-mentioned embodiment.

In addition, in variation described later, as the middle oil content structure 16 of disembarking, to be that example describes with separating mechanism with middle oil eliminator 16a and middle oil return pipe 16b, but, as described in this variation, also can adopt the structure of oil return pipe 16b in the middle of the lower end of the header box 16d that the inlet of intercooler 7 is provided with connects.

(4) variation 2

In above-mentioned embodiment and variation thereof, as compressing mechanism 2, be made of with the rear section side compression member the compressor 21 of a secondary compressed configuration and compress the contract compressing mechanism 2 of two stage compression types of the cold-producing medium of discharging in the parts of leading portion side pressure from 2 compression member 2c, 2d successively, the compressor of the single stage compress structure that two compression member of also can connecting are driven by a drive motor for compressor rotation constitutes the compressing mechanism 2 of secondary compressed configuration.

As shown in Figure 5, in the above-described embodiment, compressor 22 that can hold compression member 2c and the compressor 23 that holds compression member 2d by being connected in series two, thereby constitute compressing mechanism 2, will with the same middle oil content of above-mentioned embodiment contract the part between the inlet of parts 2c (that is, compressor 22) and intercooler 7 of leading portion side pressure that structure 16 (the middle oil content with middle oil eliminator 16a and middle oil return pipe 16b disembark structure 16) is arranged on intermediate refrigerant pipe 8 of disembarking.Herein, compressing mechanism 2 has compressor 22 and compressor 23.Compressor 22 adopts a kind of closed structure that holds drive motor for compressor 22b, driving shaft 22c and compression member 2c in casing 22a.Drive motor for compressor 22b and driving shaft 22c link, and driving shaft 22c and compression member 2c link.Compressor 23 adopts a kind of closed structure that holds drive motor for compressor 23b, driving shaft 23c and compression member 2d in casing 23a.Drive motor for compressor 23b and driving shaft 23c link, and driving shaft 23c and compression member 2d link.Compressing mechanism 2 is same with above-mentioned embodiment and variation thereof, suck cold-producing medium from suction line 2a, compress the cold-producing medium that this is inhaled into compression member 2c, discharge to intermediate refrigerant pipe 8 then, make the cold-producing medium that is discharged to intermediate refrigerant pipe 8 suck compression member 2d, after continuing compressed refrigerant, discharge to discharge pipe 2b.

In the structure of this variation 2, refrigerator oil also can stop leading portion side pressures in being accommodated in compressor 22 to be contracted the cold-producing medium that parts 2c discharges flows into intercooler 7, therefore, can prevent that refrigerator oil from accumulating in the intercooler 7, prevent that the machine oil of compressing mechanism 2 from exhausting.In addition, can prevent that the heat transfer property that accumulates in the intercooler 7 that causes in the intercooler 7 because of refrigerator oil from descending and pressure loss increase, and can improve the performance of aircondition 1.

(5) variation 3

In above-mentioned embodiment and variation thereof, adopted with the rear section side compression member and compressed the contract compressing mechanism 2 of two stage compression types of the cold-producing medium of discharging in the parts of leading portion side pressure from 2 compression member 2c, 2d successively, also can adopt with the rear section side compression member and compress the contract compressing mechanism 102 of three stage compression types of the cold-producing medium of discharging in the parts of leading portion side pressure from 3 compression member successively.

As shown in Figure 6, in the above-described embodiment, the compressor 24 and compression member 102d, the 102e that are accommodated in wherein by two compression member 102c in parallel are accommodated in wherein compressor 25, thereby can constitute compressing mechanism 102, the part between the inlet of the compression member 102c of the leading portion side of intermediate refrigerant pipe 8 (be used for connecting compression member 102c and compression member 102d) and intercooler 7; And the part between the inlet of the compression member 102d of the leading portion side of intermediate refrigerant pipe 8 (connecting compression member 102d and compression member 102e) and intercooler 7, can be provided with and the same middle oil content of the above-mentioned embodiment structure 16 (that is, the middle oil content with middle oil eliminator 16a and middle oil return pipe 16b disembark structure 16) of disembarking.Herein, compressing mechanism 102 by and compression member of coupling cold-producing medium is carried out the compressor 24 of single stage compress and with 2 compression member cold-producing medium is carried out secondary compressor for compressing 25 constituting.Compressor 24 is same with the compressor 22,23 that the single stage compress in the above-mentioned variation 3 is constructed, and adopts a kind of closed structure that holds drive motor for compressor 24b, driving shaft 24c and compression member 102c in casing 24a.Drive motor for compressor 24b and driving shaft 24c link, and driving shaft 24c and compression member 102c link.In addition, the compressor 21 of the secondary compressed configuration in compressor 25 and the above-mentioned embodiment is same, adopts a kind of closed structure that holds drive motor for compressor 25b, driving shaft 25c and compression member 102d, 102e in casing 25a.Drive motor for compressor 25b and driving shaft 25c link, and this driving shaft 25c and two compression member 102d, 102e link.Compressor 24 sucks cold-producing medium from suction line 102a, utilizes compression member 102c to compress the cold-producing medium that this is inhaled into, then to being used for 8 discharges of the intermediate refrigerant pipe among the compression member 102d that it sucks with the rear section side of compression member 102c is connected.The cold-producing medium that compressor 25 will be discharged to this intermediate refrigerant pipe 8 sucks among the compression member 102d, and further compressed refrigerant, then to being used for 8 discharges of the intermediate refrigerant pipe among the compression member 102e that it sucks with the rear section side of compression member 102d is connected, to be spued to the cold-producing medium suction compression member 102e of intermediate refrigerant pipe 8, and further compressed refrigerant, discharge to discharge pipe 102b then.

In addition, also can replace structure shown in Figure 6 (that is, the structure of the compressor 24 of single stage compress formula in parallel and the compressor 25 of two stage compression types), as shown in Figure 7, adopt the structure of the compressor 27 of the compressor 26 of two stage compression types in parallel and single stage compress formula.In the case, because compressor 26 has compression member 102c, 102d, compressor 27 has compression member 102e, and is therefore same with structure shown in Figure 7, can access the structure of three compression member 102c, 102d in parallel, 102e.In addition, since compressor 26 adopt with above-mentioned embodiment in the same structure of compressor 21, compressor 27 adopt with above-mentioned variation 3 in the same structure of compressor 22,23, therefore, the symbol of the various piece of expression except that compression member 102c, 102d, 102e is replaced as numeral 26 and numeral 27 respectively, omit its explanation herein.

In addition, also can replace structure shown in Figure 6 (that is, the structure of the compressor 25 of single stage compress formula in parallel and the compressor 24 of two stage compression types), as shown in Figure 8, adopt the structure of the compressor 24,28,27 of three single stage compress formulas in parallel.In the case, because compressor 24 has compression member 102c, compressor 28 has compression member 102d, compressor 27 has compression member 102e, therefore, same with Fig. 6 and structure shown in Figure 7, can access the structure of three compression member 102c, 102d in parallel, 102e.In addition and since compressor 24,28 adopt with above-mentioned variation 3 in the same structure of compressor 22,23, therefore, the symbol of the various piece of expression except that compression member 102c, 102d is replaced as digital 24 and digital 28 respectively,, omit its explanation herein.

So in this variation, compressing mechanism 102 has three compression member 102c, 102d, 102e, and compress the cold-producing medium that leading portion side pressure from these compression member 102c, 102d, 102e is contracted and discharged in the parts successively with the rear section side compression member.Refrigerant line 110 in this variation is made of compressing mechanism 102, intermediate refrigerant pipe 8, intercooler 7 and the middle oil content structure 16 etc. of disembarking.

Below, use Fig. 6～Figure 10, the operation of the aircondition 1 of this variation is described.Herein, Fig. 9 is the pressure-enthalpy line chart of the freeze cycle during cooling operation in the variation 3, and Figure 10 is the temperature-entropy line chart of the freeze cycle during cooling operation in the variation 3.In addition, the control of the running in the following cooling operation is undertaken by above-mentioned control part (not shown).In addition, in the following description, high pressure in " high pressure " expression freeze cycle (promptly, some D among Fig. 9,10, the pressure among D ', the E), low pressure in " low pressure " expression freeze cycle (promptly, pressure among some A, the F among Fig. 9,10), middle press (that is the pressure among the some B1 among Fig. 9,10, B2, B2 ', C1, C2, the C2 ') in " the middle pressure " expression freeze cycle.

If drive compression mechanism 102, so, low pressure refrigerant (with reference to the some A among Fig. 6～Figure 10) is inhaled into the compressing mechanism 102 from suction line 102a, at first, be compressed after parts 102c is compressed to intermediate pressure, be discharged to and be used for making the cold-producing medium of from parts 102c is contracted in the leading portion side pressure, discharging to suck the intermediate refrigerant pipe 8 (with reference to the some B1 among Fig. 6～Figure 10) of rear section side compression member 102d.The compacting cryogen flows in the middle of the formation of the part setting between the inlet of parts 102c and intercooler 7 is contracted in the leading portion side pressure of intermediate refrigerant pipe 8 oil content and disembarks among the middle oil eliminator 16a of structure 16 in the middle of being discharged from from parts 102c is contracted in this leading portion side pressure, after the refrigerator oil of Liu Ruing is separated with it, be sent to intercooler 7.In addition, oil content was disembarked among the middle oil return pipe 16b of structure 16 in the middle of the refrigerator oil that is separated from centre compacting cryogen in the oil eliminator 16a of this centre flowed into and constitutes, return compressing mechanism 102 (being suction line 102a) herein after the mechanism of decompressor 16c decompression in the middle of being arranged among the oil return pipe 16b, sucked once more in the compressing mechanism 102.Then, in middle oil content is disembarked structure 16 refrigerator oil by compacting cryogen in the middle of after wherein separate, thereby in intercooler 7 with carry out heat exchange be cooled (with reference to the some C1 among Fig. 6～Figure 10) as the water of cooling source or air.Then, the cold-producing medium that is cooled in this intercooler 7 is inhaled among the compression member 102d that is connected with the rear section side of compression member 102c, after quilt further compresses and becomes high middle the pressure, be discharged to the intermediate refrigerant pipe 8 (with reference to the some B2 among Fig. 6～Figure 10) that is used for making the cold-producing medium suction rear section side compression member 102e that from parts 102d is contracted in the leading portion side pressure, discharges.The compacting cryogen flows in the middle of the formation of the part setting between the inlet of parts 102d and intercooler 7 is contracted in the leading portion side pressure of intermediate refrigerant pipe 8 oil content and disembarks among the middle oil eliminator 16a of structure 16 in the middle of being discharged from from parts 102d is contracted in this leading portion side pressure, after the refrigerator oil of Liu Ruing is separated with it, be sent to intercooler 7.In addition, oil content was disembarked among the middle oil return pipe 16b of structure 16 in the middle of the refrigerator oil that is separated from centre compacting cryogen in the oil eliminator 16a of this centre flowed into and constitutes, return the suction line 102a of compressing mechanism 2 after the mechanism of decompressor 16c decompression in the middle of being arranged among the oil return pipe 16b, sucked once more in the compressing mechanism 102.Then, in middle oil content is disembarked structure 16 refrigerator oil by compacting cryogen in the middle of after wherein separate, thereby in intercooler 7 with carry out heat exchange be cooled (with reference to the some C2 among Fig. 6～Figure 10) as the water of cooling source or air.Then, the cold-producing medium that is cooled in this intercooler 7 is inhaled among the compression member 102e that is connected with the rear section side of compression member 102d, after further compressing, is discharged to discharge pipe 102b (with reference to the some D Fig. 6～Figure 10) from compressing mechanism 102.Herein, the high-pressure refrigerant that is discharged from from compressing mechanism 102 is according to three grades of squeeze operations of compression member 102c, 102d, 102e, is compressed the pressure that becomes above critical pressure (that is the critical pressure Pcp among the critical point CP shown in Figure 9).The high-pressure refrigerant that is discharged from from this compressing mechanism 102 flows into and constitutes oil content and disembark among the oil eliminator 41a of structure 41, and the refrigerator oil of Liu Ruing is separated with it.The refrigerator oil that is separated from high-pressure refrigerant in oil eliminator 41a flows into and constitutes oil content and disembark among the oil return pipe 41b of structure 41, return compressing mechanism 102 (being suction line 102a) herein after being arranged on the mechanism of decompressor 41c decompression among the oil return pipe 41b, sucked once more in the compressing mechanism 102.Then, in oil content is disembarked structure 41 refrigerator oil by after the unidirectional mechanism 42, being sent to can be as the heat source side heat exchanger 4 of the cooler of cold-producing medium by the high-pressure refrigerant after wherein separate.The high-pressure refrigerant that is sent to heat source side heat exchanger 4 carries out heat exchange with water or air as cooling source in heat source side heat exchanger 4, thereby is cooled (with reference to the some E among Fig. 6～Figure 10).The high-pressure refrigerant that is cooled in heat source side heat exchanger 4 is inflated the cold-producing medium that becomes the gas-liquid two-phase state of low pressure after mechanism 5 decompression, be sent to can be as the heater of cold-producing medium utilize square heat-exchanger 6 (with reference to the some F among Fig. 6～Figure 10).Then, the cold-producing medium of gas-liquid two-phase state that is sent to the low pressure of utilizing square heat-exchanger 6 carries out being heated after the heat exchange evaporation (with reference to the some A among Fig. 6～Figure 10) then with water or air as heating source in utilizing square heat-exchanger 6.Utilize at this that heated low pressure refrigerant is sucked in the compressing mechanism 102 once more in square heat-exchanger 6.Adopt aforesaid way to carry out cooling operation.

So, in the structure of this variation, owing in the intermediate refrigerant pipe 8 that is used for making the cold-producing medium suction compression member 102d that from compression member 102c, discharges, intercooler 7 is set, and in the intermediate refrigerant pipe 8 that is used for making the cold-producing medium suction rear section side compression member 102e that from compression member 102d, discharges, intercooler 7 is set, therefore, with the situation that intercooler 7 is not set (in the case, at Fig. 9, among Figure 10, order according to an an an A → B1 → B2 ' (C2 ') → D ' → E → F is carried out freeze cycle) compare, be inhaled into the temperature of the cold-producing medium among the compression member 102d of rear section side of compression member 102c, and the temperature that is inhaled into the cold-producing medium among the compression member 102e of rear section side of compression member 102d descends (with reference to the some B1 among Figure 10, C1, B2, C2), the temperature of the cold-producing medium of discharging from compression member 102e also can descend (with reference to the some D among Figure 10, D ').Therefore, in the structure of this variation, in the heat source side heat exchanger 4 of the cooler that can be used as high-pressure refrigerant, compare with the situation that intercooler 7 is not set, can dwindle the temperature difference as water or the air and the cold-producing medium of cooling source, the radiation loss of the some B1, the B2 ' that are equivalent to link among Figure 10 (C2 '), area size that D ', D, C2, B2, C1 constituted can be further reduced, therefore running efficiency can be further improved.And this area is bigger than the area in the two stage compression type freeze cycle of above-mentioned embodiment and variation thereof, therefore, compares with above-mentioned embodiment and variation thereof, can further improve running efficiency.

In addition, in the structure of this variation, after being used for the refrigerator oil of discharging with cold-producing medium separated, part setting between the inlet of the compression member 102c of the leading portion side of intermediate refrigerant pipe 8 and intercooler 7 makes the middle oil content of its suction of the returning compressing mechanism 2 one side structure 16 of disembarking from cold-producing medium from parts 102c is contracted in the leading portion side pressure, and, after being used for the refrigerator oil of discharging with cold-producing medium separated, part setting between the inlet of the compression member 102d of the leading portion side of intermediate refrigerant pipe 8 and intercooler 7 makes the middle oil content of its suction of the returning compressing mechanism 2 one side structure 16 of disembarking from cold-producing medium from parts 102d is contracted in the leading portion side pressure, therefore, same with above-mentioned embodiment and variation thereof, can prevent that the machine oil of compressing mechanism 102 from exhausting.

In addition, oil content is not disembarked under the situation of structure 16 in the middle of be provided with, because of refrigerator oil accumulates in the intercooler 7, cause the heat transfer property of intercooler 7 to descend, heat-shift in the intercooler 7 (promptly, Fig. 9 mid point B1, enthalpy difference between C1, point B2, enthalpy difference between some C2) reduces, therefore, might can't reduce the radiation loss in the heat source side heat exchanger 4, and, because of refrigerator oil accumulates in the intercooler 7, cause the pressure loss of intercooler 7 to increase, be inhaled into rear section side compression member 102d and compression member 102e cold-producing medium pressure (promptly, some C1 among Fig. 9 and some C2) reduce, the consumption of power of rear section side compression member 102d and compression member 102e might increase, still, because the oil content structure 16 of disembarking in the middle of being provided with, therefore, same with above-mentioned embodiment and variation thereof, can improve the performance of aircondition 1.

In addition, compressor 25 (with reference to Fig. 6) as two stage compression types that constitute compressing mechanism 102, employing is inhaled into the contract cold-producing medium of parts 102d of leading portion side pressure and is full of casing 25a, the low pressure dome-shaped in the space that refrigerator oil accumulated in the 25a, from the leading portion side pressure contract cold-producing medium that parts 102d discharges be full of space in the casing 25a that refrigerator oil accumulates in the middle of press dome-shaped, the cold-producing medium of discharging from rear section side compression member 102e is full of under any one the situation the high pressure dome-shaped in the space in the casing 25a that refrigerator oil accumulates, by the structure 16 of disembarking of oil content in the middle of being provided with, can obtain also to prevent that the machine oil of compressing mechanism 102 from exhausting the equivalence fruit, particularly under the situation of the compressor that adopts the high pressure dome-shaped as the compressor 25 that constitutes compressing mechanism 102, after the cold-producing medium of discharging from rear section side compression member 102e is discharged to space in the casing 25a that refrigerator oil accumulates, be discharged to outside the casing 25a, therefore, the oil mass of the refrigerator oil in the cold-producing medium is few, and directly be expelled to outside the casing 25a from the leading portion side pressure cold-producing medium that parts 102d discharges that contracts, therefore, the oil mass of the refrigerator oil in the cold-producing medium is many, the oil mass that accumulates in the refrigerator oil in the intercooler 7 might increase, therefore, be provided with in the middle of the oil content structure 16 of disembarking very effective.For the compressor 26 (with reference to Fig. 7) of two stage compression types that constitute compressing mechanism 102, same with compressor 25 under the situation that adopts the high pressure dome-shaped, the oil content structure 16 of disembarking is very effective in the middle of being provided with.

In addition, omit its detailed explanation herein, still, also can replace the compressing mechanism 102 of three stage compression types, adopt the multi-stage compression mechanism of as level Four compression etc., Duoing, in the case, also can obtain the effect identical with this variation than three stage compression types.

(6) variation 4

In above-mentioned embodiment and variation thereof, the compressing mechanism 2 of the multi-stage compression formula of compressing successively with a plurality of compression member and compressing mechanism 102 adopt the structure that only has a system, for example, under the big situation of utilizing square heat-exchanger 6 of concatenation ability and connect under a plurality of situations of utilizing square heat-exchanger 6, the compressing mechanism 2 of multi-stage compression formula and compressing mechanism 102 also can adopt the compressing mechanism of the multi-stage compression formula arranged side by side that a plurality of systems are connected side by side.

As shown in figure 11, can adopt that having is connected in parallel and have compression member 203c, 203d two stage compression types the 1st compressing mechanism 203 and have the compressing mechanism 202 of the 2nd compressing mechanism 204 of two stage compression types of compression member 204c, 204d, thereby constitute refrigerant line 210.

In this variation, the 1st compressing mechanism 203 constitutes by with two compression member 203c, 203d cold-producing medium being carried out secondary compressor for compressing 29, and it is with the 1st suction manifold 203a that is responsible for 202a branch from the suction of compressing mechanism 202 and be responsible for the 1st exhaust outlet 203b that 202b converges with the discharge of compressing mechanism 202 and be connected.In this variation, the 2nd compressing mechanism 204 constitutes by with two compression member 204c, 204d cold-producing medium being carried out secondary compressor for compressing 30, and it is connected with being responsible for the 2nd suction manifold 204a that 202a tells from the suction of compressing mechanism 202 and being responsible for the 2nd exhaust outlet 204b that 202b converges with the discharge of compressing mechanism 202.In addition, because the structure of compressor 29,30 is identical with the compressor 21 in the above-mentioned embodiment, therefore, the symbol of representing the various piece except compression member 203c, 203d, 204c, 204d is replaced as numeral 29 and numeral 30 respectively, omit its explanation herein.Compressor 29 sucks cold-producing medium from the 1st suction manifold 203b, after compressing this cold-producing medium that is inhaled into compression member 203c, it is expelled to the middle arm 81 of the 1st entrance side that constitutes intermediate refrigerant pipe 8, the cold-producing medium that is expelled to the middle arm 81 of the 1st entrance side is made among its suction compression member 203d after being responsible for the middle arm 83 of the 82 and the 1st outlet side in the middle of the formation intermediate refrigerant pipe 8, behind the continuation compressed refrigerant it is expelled to the 1st exhaust outlet 203b.Compressor 30 sucks cold-producing medium from the 1st suction manifold 204b, after compressing this cold-producing medium that is inhaled into compression member 204c, it is expelled to the middle arm 84 of the 2nd entrance side that constitutes intermediate refrigerant pipe 8, make the cold-producing medium that is expelled to arm 84 in the middle of the 2nd entrance side by constitute intermediate refrigerant pipe 8 in the middle of be responsible in the middle of the 82 and the 2nd outlet side and behind the arm 85 it sucked among compression member 204d, continue behind the compressed refrigerant to it being expelled to the 2nd exhaust outlet 204b.In this variation, intermediate refrigerant pipe 8 be used for from compression member 203d, the compression member 203c that the leading portion side of 204d connects, the cold-producing medium of discharging among the 204c sucks and compression member 203c, the compression member 203d that the rear section side of 204c connects, refrigerant pipe among the 204d mainly comprises: with the leading portion side pressure of the 1st compressing mechanism 203 arm 81 in the middle of the 1st entrance side that discharge one side of parts 203c is connected that contracts, with the leading portion side pressure of the 2nd compressing mechanism 204 arm 84 in the middle of the 2nd entrance side that discharge one side of parts 204c is connected that contracts, arm 81 in the middle of two entrance sides, the 84 middle persons in charge 82 that converge, be responsible for from the centre 82 branches then with the 1st outlet side that suction one side of the rear section side compression member 203d of the 1st compressing mechanism 203 is connected in the middle of arm 83, and be responsible for from the centre 82 branches then with the 2nd outlet side that suction one side of the rear section side compression member 204d of the 2nd compressing mechanism 204 is connected in the middle of arm 85.In addition, discharging person in charge 202b is to be used for being sent to the refrigerant pipe of heat source side heat exchanger 4 from the cold-producing medium that compressing mechanism 202 is discharged, with discharge to be responsible for the 1st exhaust outlet 203b that 202b is connected in be provided with the 1st oil content disembark structure 241 and the 1st unidirectional mechanism 242, with discharge the 2nd exhaust outlet 204b that person in charge 202b is connected in be provided with the 2nd oil content disembark structure 243 and the 2nd unidirectional mechanism 244.Disembark structure 241 is used for being mingled with from the cold-producing medium that the 1st compressing mechanism 203 is discharged refrigerator oil of the 1st oil content is separated from cold-producing medium and is made its suction of returning compressing mechanism 202 one side then, mainly has: the 1st oil eliminator 241a that the refrigerator oil that will be mingled with from the cold-producing medium that the 1st compressing mechanism 203 is discharged is separated from cold-producing medium, be connected with the 1st oil eliminator 241a and the refrigerator oil that will be separated from cold-producing medium is sent the 1st oil return pipe 241b of suction one side of compressing mechanism 202 back to.Disembark structure 243 is used for being mingled with from the cold-producing medium that the 2nd compressing mechanism 204 is discharged refrigerator oil of the 2nd oil content is separated from cold-producing medium and is made its suction of returning compressing mechanism 202 one side then, mainly has: the 2nd oil eliminator 243a that the refrigerator oil that will be mingled with from the cold-producing medium that the 2nd compressing mechanism 204 is discharged is separated from cold-producing medium, be connected with the 2nd oil eliminator 243a and the refrigerator oil that will be separated from cold-producing medium is sent the 2nd oil return pipe 243b of suction one side of compressing mechanism 202 back to.In this variation, the 1st oil return pipe 241b is connected with the 2nd suction manifold 204a, and the 2nd oil return pipe 243c is connected with the 1st suction manifold 203a.Therefore, owing to deviation occurs between the oil mass of the refrigerator oil that the oil mass that accumulates in the refrigerator oil in the 1st compressing mechanism 203 is interior with accumulating in the 2nd compressing mechanism 204, thereby produce deviation between the oil mass of the oil mass that causes the refrigerator oil that from the cold-producing medium that the 1st compressing mechanism 203 is discharged, is mingled with and the refrigerator oil that from the cold-producing medium of the 2nd compressing mechanism 204 discharges, is mingled with, in this case, refrigerator oil also can return compressing mechanism 203 more, less one of the oil mass of refrigerator oil in 204, the deviation between the oil mass of the refrigerator oil that the oil mass that accumulates in the refrigerator oil in the 1st compressing mechanism 203 is interior with accumulating in the 2nd compressing mechanism 204 also is eliminated.In addition, in this variation, the 1st suction manifold 203a according to from and the fluidic junction of the 2nd oil return pipe 243b to and suck between the fluidic junction of being responsible for 202a part towards with suck the mode that the fluidic junction of being responsible for 202a is downward gradient and constitute, the 2nd suction manifold 204a according to from and the fluidic junction of the 1st oil return pipe 241b to and suck between the fluidic junction of being responsible for 202a part towards with suck the mode that the fluidic junction of being responsible for 202a is the decline ladder and constitute.Therefore, even any one in the compressing mechanism 203,204 is in halted state, return refrigerator oil with the corresponding suction manifold of the compressing mechanism that is in halted state from the oil return pipe corresponding with the compressing mechanism that is turning round and will return to suck and be responsible for 202a, the compressing mechanism that is turning round is difficult for the generator oil consumption to the greatest extent.In oil return pipe 241b, 243b, be provided with mechanism of decompressor 241c, 243c that the refrigerator oil to flow through oil return pipe 241b, 243b reduces pressure.Unidirectional mechanism 242,244 is used for allowing the discharge one effluent heat source end heat exchanger 4 of cold-producing medium from compressing mechanism 203,204, and block refrigerant flows to discharge one side of compressing mechanism 203,204 from heat source side heat exchanger 4.

So, in this variation, compressing mechanism 202 constitutes with lower member by connecting side by side: have two compression member 203c, 203d and according to compress successively with the rear section side compression member leading portion side pressure from these compression member 203c, 203d contract the 1st compressing mechanism 203 that the mode of the cold-producing medium of discharging in the parts constitutes, have two compression member 204c, 204d and according to compress leading portion side pressure from these compression member 204c, 204d the 2nd compressing mechanism 204 that the mode of the cold-producing medium of discharging in the parts constitutes that contracts successively with the rear section side compression member.

In this variation, intercooler 7 be set at constitute intermediate refrigerant pipe 8 in the middle of be responsible in 82, it is cooling from the contract heat exchanger of cold-producing medium that parts the 203c cold-producing medium of discharging and the parts 204c that contracts from the leading portion side pressure of the 2nd compressing mechanism 204 the discharge cold-producing medium after converging of the leading portion side pressure of the 1st compressing mechanism 203.That is, intercooler 7 is general in two compressing mechanisms 203,204 as cooler.Therefore, when in the compressing mechanism 202 of the multi-stage compression formula arranged side by side of the compressing mechanism 203,204 of the multi-stage compression formula of the multisystem that is connected in parallel, intercooler 7 being set, can simplify the circuit structure around the compressing mechanism 202.

In addition, in this variation, middle oil content disembark structure 16 be set at constitute intermediate refrigerant pipe 8 in the middle of be responsible for part between the inlet of the fluidic junction of arm 81,84 in the middle of 82 the entrance side and intercooler 7, and same with intercooler 7, be set in two compressing mechanisms 203,204 according to universal mode.In addition, in this variation, the suction of the oil export of oil eliminator 16a and compressing mechanism 202 was responsible between the 202a in the middle of middle oil return pipe 16b connected.

In addition, in the 1st entrance side intermediate section arm 81 that constitutes intermediate refrigerant pipe 8, be provided with the unidirectional 81a of mechanism, be used for allowing that cold-producing medium contracts discharge one effluent of parts 203c to middle female pipe 82 1 sides from the leading portion side pressure of the 1st compressing mechanism 203, and block refrigerant from middle female pipe 82 1 effluents to contract discharge one side of parts 203c of leading portion side pressure, in the 2nd entrance side intermediate section arm 84 that constitutes intermediate refrigerant pipe 8, be provided with the unidirectional 84a of mechanism, be used for allowing that cold-producing medium contracts discharge one effluent of parts 204c to middle female pipe 82 1 sides from the leading portion side pressure of the 2nd compressing mechanism 203, and block refrigerant from middle female pipe 82 1 effluents to contract discharge one side of parts 204c of leading portion side pressure.In this variation, use check valve as the unidirectional 81a of mechanism, 84a.Therefore, even compressing mechanism 203, in 204 any one is in halted state, the leading portion side pressure of compressing mechanism from running contract discharge one side of parts of leading portion side pressure that cold-producing medium that parts discharge arrives the compressing mechanism in stopping then by intermediate refrigerant pipe 8 that contracts can not take place yet, therefore, contract cold-producing medium that parts discharge of the leading portion side pressure of compressing mechanism from running can not take place arrive suction one side of compressing mechanism 202 then by the leading portion side pressure of the compressing mechanism in the stopping parts that contract, the refrigerator oil of the compressing mechanism in stopping to flow out, so, during compressing mechanism in startup stops, be difficult for taking place the situation of refrigerator oil deficiency.In addition, under the situation of the priority that running is set between the compressing mechanism 203,204 (for example, under the situation of the compressing mechanism that uses preferential running the 1st compressing mechanism 203), the compressing mechanism that meets in above-mentioned the stopping only to be confined to the 2nd compressing mechanism 204, therefore, in the case, the unidirectional mechanism 84a corresponding with the 2nd compressing mechanism 204 also can be set.

In addition, as mentioned above, under the situation of the compressing mechanism that uses preferential running the 1st compressing mechanism 203, intermediate refrigerant pipe 8 is set at compressing mechanism 203 according to universal mode, in 204, therefore, the cold-producing medium of discharging from parts 203c is contracted in the leading portion side pressure corresponding with the 1st compressing mechanism 203 running is by the 2nd outlet side intermediate section arm 85 of intermediate refrigerant pipe 8, suction one side of the rear section side compression member 204d of the 2nd compressing mechanism 204 during arrival stops, like this, the leading portion side pressure of the 1st compressing mechanism 203 from running is contracted in the rear section side compression member 204d of cold-producing medium by the 2nd compressing mechanism 204 in stopping that discharging among the parts 203c, arrive discharge one side of compressing mechanism 202 then, the refrigerator oil of the 2nd compressing mechanism 204 in stopping to flow out, during the 2nd compressing mechanism 204 in startup stops, the situation of refrigerator oil deficiency might take place.Therefore, in this variation, in the 2nd outlet side intermediate section arm 85, switch valve 85a is set, is under the situation of halted state, utilize this switch valve 85a to block flowing of cold-producing medium in the 2nd outlet side intermediate section arm 85 at the 2nd compressing mechanism 204.Like this, contract cold-producing medium that parts 203c discharges of the leading portion side pressure of the 1st compressing mechanism 203 from running just can't arrive suction one side of the rear section side compression member 204d of the 2nd compressing mechanism 204 in stopping by the 2nd outlet side intermediate section arm 85 of intermediate refrigerant pipe 8, therefore, the leading portion side pressure of the 1st compressing mechanism 203 from running is contracted in the rear section side compression member 204d of cold-producing medium by the 2nd compressing mechanism 204 in stopping that parts 203c discharges, arrive discharge one side of compressing mechanism 202 then, the refrigerator oil of the 2nd compressing mechanism 204 in difficult the stopping to flow out such situation, and, also be difficult for taking place the situation of refrigerator oil deficiency during the 2nd compressing mechanism 204 in startup stops.In addition, in variation, 85a has used magnetic valve as switch valve.

In addition, under the situation of the compressing mechanism that uses preferential running the 1st compressing mechanism 203, after the startup of the 1st compressing mechanism 203, then start the 2nd compressing mechanism 204, but, at this moment, intermediate refrigerant pipe 8 is set at compressing mechanism 203 according to universal mode, in 204, therefore, become and start down from the contract pressure of suction one side of the pressure of discharge one side of parts 203c and rear section side compression member 203d of the leading portion side pressure of the 2nd compressing mechanism 204, be difficult to stably start the 2nd compressing mechanism 204 than the contract high state of pressure of discharge one side of the pressure of suction one side of parts 203c and rear section side compression member 203d of leading portion side pressure.Therefore, in this variation, the contract startup bypass pipe 86 of suction one side of discharge one side of parts 204c and rear section side compression member 204d of the leading portion side pressure that setting is used for connecting the 2nd compressing mechanism 204, and in this startup bypass pipe 86, switch valve 86a is set, be under the situation of halted state at the 2nd compressing mechanism 204, utilize this switch valve 86a blocking-up to start flowing of cold-producing medium in the bypass pipe 86, and, utilize switch valve 85a to block flowing of cold-producing medium in the 2nd outlet side intermediate section arm 85, when starting the 2nd compressing mechanism 204, utilizing switch valve 86a that cold-producing medium is flowed through starts in the bypass pipe 86, the cold-producing medium of discharging from parts 204c is contracted in the leading portion side pressure of the 2nd compressing mechanism 204 is not collaborated with the cold-producing medium that the parts 204c that contracts from the leading portion side pressure of the 1st compressing mechanism 203 discharges, but it is sucked among the rear section side compression member 204d by starting bypass pipe 86, stable moment of the operating condition of compressing mechanism 202 (for example, the suction pressure of compressing mechanism 202, the moment that discharge pressure and intermediate pressure are stable), utilize switch valve 85a that cold-producing medium is flowed through in the 2nd outlet side intermediate section arm 85, and, utilize switch valve 86a blocking-up to start flowing of cold-producing medium in the bypass pipe 86, thereby make it can enter common cooling operation.In addition, in this variation, be connected between suction one side of an end that starts bypass pipe 86 and the rear section side compression member 204d of the switch valve 85a of the 2nd outlet side intermediate section arm 85 and the 2nd compressing mechanism 204, the other end and the leading portion side pressure of the 2nd compressing mechanism 204 are contracted and are connected between the unidirectional 84a of mechanism of discharge one side of parts 204c and the 2nd entrance side intermediate section arm 84, when starting the 2nd compressing mechanism 204, it can be started under the state of the influence that the middle splenium that is not vulnerable to the 1st compressing mechanism 203 divides.In addition, in this variation, 86a has used magnetic valve as switch valve.

In addition, operation during for the cooling operation of the aircondition 1 of this variation, except the compressing mechanism of establishing because of replacement compressing mechanism 2 202, circuit structure around the compressing mechanism 202 becomes slightly complicated and outside changing, operation (Fig. 1～Fig. 3 and relevant record the thereof) during cooling operation in basic and the above-mentioned embodiment is identical, therefore, omit its explanation herein.

In the structure of this variation 4, also can stop from the leading portion side pressure of the 1st compressing mechanism 203 refrigerator oil that the leading portion side pressure of parts 203c and the 2nd compressing mechanism 204 contracts the cold-producing medium that parts 204c discharges that contracts and flow into intercooler 7, therefore, can prevent that refrigerator oil from accumulating in the intercooler 7, prevent that the machine oil of compressing mechanism 202 from exhausting.In addition, not only can prevent that the heat transfer property that accumulates in the intercooler 7 that causes in the intercooler 7 because of refrigerator oil from descending and pressure loss increase, and can improve the performance of aircondition 1.In the structure of this variation, although adopt the compressing mechanism 202 of the multi-stage compression formula arranged side by side of the compressing mechanism 203,204 of the multi-stage compression formula of connection multisystem side by side, but, the oil content structure 16 of disembarking in the middle of being provided with in two compressing mechanisms 203,204 according to universal mode, therefore, can simplify compressing mechanism 202 circuit structure on every side.In this variation,, therefore, can guarantee to make freezing mechanism to return two compressing mechanisms 203,204 because middle oil return pipe 16b connects the oil export of middle oil eliminator 16a and the suction of compressing mechanism 202 is responsible between the 202a.

In addition, omit its detailed explanation herein, but, the compressing mechanism 203,204 that both can replace two stage compression types, adopt as three stage compression types (for example, the compressing mechanism 102 in the variation 3) wait the multi-stage compression mechanism of Duoing than two stage compression types like that, also can adopt the compressing mechanism of multi-stage compression formula arranged side by side of the compressing mechanism of the multi-stage compression formula more than three systems of connection arranged side by side, in the case, also can obtain the effect identical with this variation.

(7) variation 5

In above-mentioned variation 4, as shown in figure 11, the oil content structure 16 of disembarking in the middle of being provided with according to universal mode in 2 compressing mechanisms 203,204 also can be as shown in figure 12, is provided with according to the mode corresponding with each compressing mechanism 203,204.For example, for the 1st compressing mechanism 203, can with the leading portion side pressure contract be provided with in the arm 81 in the middle of the 1st entrance side that discharge one side of parts 203c is connected in the middle of the oil content structure 16 of disembarking, for the 2nd compressing mechanism 204, can with the leading portion side pressure contract be provided with in the arm 84 in the middle of the 2nd entrance side that discharge one side of parts 204c is connected in the middle of the oil content structure 16 of disembarking.

In the structure of this variation 5, identical with above-mentioned variation 4, also can stop from the leading portion side pressure of the 1st compressing mechanism 203 refrigerator oil that the leading portion side pressure of parts 203c and the 2nd compressing mechanism 204 contracts the cold-producing medium that parts 204c discharges that contracts and flow into intercooler 7, therefore, can prevent that refrigerator oil from accumulating in the intercooler 7, prevent that the machine oil of compressing mechanism 202 from exhausting.In addition, not only can prevent that the heat transfer property that accumulates in the intercooler 7 that causes in the intercooler 7 because of refrigerator oil from descending and pressure loss increase, and can improve the performance of aircondition 1.In the structure of this variation, the oil content structure 16 of disembarking in the middle of being provided with according to the mode corresponding with each compressing mechanism 203,204, therefore, the leading portion side pressure contract parts 203c, 204c near be provided with in the middle of oil eliminator 16a, so just can the leading portion side pressure contract parts 203c, 204c near from cold-producing medium, separate refrigerator oil, and, not only can prevent that refrigerator oil from accumulating in the intercooler 7, and can prevent that it from accumulating in the intermediate refrigerant pipe 8 of the middle person in charge 82 and the middle arm 81,84 of entrance side etc.

In structure shown in Figure 12, also can connect in the part that the mode that is downward gradient according to the fluidic junction with suck being responsible for 202a towards the 2nd suction manifold 204a constitutes and the disembark middle oil return pipe 16b of structure 16 of corresponding and middle the oil content that be provided with of the 1st compressing mechanism 203, the part connection that constitutes in the mode that is downward gradient according to the fluidic junction with suction person in charge 202a towards the 1st suction manifold 203a is the disembark middle oil return pipe 16b (with reference to Figure 13) of structure 16 of corresponding and middle oil content that establish with the 2nd compressing mechanism 204.

In this structure, except above-mentioned effect, owing to deviation occurs between the oil mass of the refrigerator oil that the oil mass that accumulates in the refrigerator oil in the 1st compressing mechanism 203 is interior with accumulating in the 2nd compressing mechanism 204, thereby produce deviation between the oil mass of the refrigerator oil that is mingled with the cold-producing medium of the oil mass that causes the refrigerator oil that from the cold-producing medium that parts 203c discharges is contracted in the leading portion side pressure of the 1st compressing mechanism 203, is mingled with and the parts 204c discharge of contracting from the leading portion side pressure of the 2nd compressing mechanism 204, in this case, refrigerator oil also can return compressing mechanism 203 more, less one of the oil mass of refrigerator oil in 204, the deviation between the oil mass of the refrigerator oil that the oil mass that accumulates in the refrigerator oil in the 1st compressing mechanism 203 is interior with accumulating in the 2nd compressing mechanism 204 also is eliminated.And, even any one in the compressing mechanism 203,204 is in halted state, return refrigerator oil with the corresponding suction manifold of the compressing mechanism that is in halted state from the middle oil return pipe corresponding with the compressing mechanism that is turning round and will return to suck and be responsible for 202a, the compressing mechanism that is turning round is difficult for the generator oil consumption to the greatest extent.

(8) variation 6

In above-mentioned embodiment and variation thereof, in can the aircondition 1 of cooling operation, intercooler 7 is set in intermediate refrigerant pipe 8, and the oil content structure 16 of disembarking in the middle of being provided with between the inlet of the compression member of the leading portion side of intermediate refrigerant pipe 8 and intercooler 8, dwindling with this can be as the radiation loss in the heat source side heat exchanger 4 of the cooler of cold-producing medium, thereby raising running efficiency, the machine oil that obtains to prevent the compressing mechanism that turning round simultaneously exhausts the equivalence fruit, except this structure, can also adopt the structure that can switch cooling operation and heat running, and be provided with and be used for making it return the rear section side playpipe of rear section side compression member 2d then at heat source side heat exchanger 4 or utilize the cold-producing medium that is cooled in the square heat-exchanger 6 to shunt.

For example, as shown in figure 14, in the above-mentioned embodiment of the compressing mechanism 2 that adopts two stage compression types, setting can be switched cooling operation and be heated the switching mechanism 3 of running, replace expansion mechanism 5 and reservoir inlet expansion mechanism 5a and reservoir outlet expansion mechanism 5b are set, and bridge circuit 17, reservoir (receiver) 18, rear section side playpipe 19 and economizer heat exchanger 20 are set, thereby can form refrigerant line 310.

Switching mechanism 3 is the mechanisms that are used for switching the refrigerant flow direction in the refrigerant line 310, in order to make when the cooling operation heat source side heat exchanger 4 can be as the cooler that is compressed 2 refrigerant compressed of mechanism, and make the heater that utilizes square heat-exchanger 6 can be used as the cold-producing medium that in heat source side heat exchanger 4, is cooled, can connect discharge one side of compressing mechanism 2 and an end of heat source side heat exchanger 4, suction one side that connects compressor 21 simultaneously with utilize square heat-exchanger 6 (with reference to the solid line of the switching mechanism 3 of Figure 14, below, the state of this switching mechanism 3 is as " cooling operation state "), utilize square heat-exchanger 6 can be used as the cooler that is compressed 2 refrigerant compressed of mechanism in order when system warms up running, to make, and make heat source side heat exchanger 4 can be used as the heater of the cold-producing medium that in utilizing square heat-exchanger 6, is cooled, can connect discharge one side of compressing mechanism 2 and utilize square heat-exchanger 6, connect suction one side of compressing mechanism 2 and an end of heat source side heat exchanger 4 simultaneously (with reference to the dotted line of the switching mechanism 3 of Figure 14, below, the state of this switching mechanism 3 is as " heating operating condition ").In the present embodiment, switching mechanism 3 is and suction one side of compressing mechanism 2, discharge one side, the heat source side heat exchanger 4 of compressing mechanism 2 and four way reversing valves that utilize square heat-exchanger 6 to be connected.In addition, switching mechanism 3 is not limited to four way reversing valves, for example also can be by combination a plurality of magnetic valves etc., and make it have function with above-mentioned same switching refrigerant flow direction.

So, switching mechanism 3 just can switch make cold-producing medium successively at compressing mechanism 2, heat source side heat exchanger 4, expansion mechanism 5a, 5b, utilize the cooling operation state that circulates in the square heat-exchanger 6; And make cold-producing medium successively at compressing mechanism 2, utilize in square heat-exchanger 6, expansion mechanism 5a, 5b, the heat source side heat exchanger 4 operating condition that heats of circulation.

In addition, in intermediate refrigerant pipe 8, connect intercooler bypass pipe 9, with bypass intercooler 7.This intercooler bypass pipe 9 has the function as the middle refrigerating function limiting mechanism of the flow of the cold-producing medium that limits the intercooler 7 of flowing through.In intercooler bypass pipe 9, be provided with intercooler bypass cock valve 11.In the present embodiment, intercooler bypass cock valve 11 is magnetic valves.This intercooler bypass cock valve 11 controlled closing when switching mechanism 3 is in the cooling operation state is in controlled opening when heating operating condition at switching mechanism 3.

In addition, in intermediate refrigerant pipe 8, from (that is, the inlet side of intercooler 7 with the connecting portion of connecting portion intercooler bypass pipe 9 to outlet one side of intercooler 7) is provided with cooler switch valve 12 to the position of intercooler 7 one sides with the connecting portion of intercooler bypass pipe 9.This cooler switch valve 12 has the function as the middle refrigerating function limiting mechanism of the flow of the cold-producing medium that limits the intercooler 7 of flowing through.In the present embodiment, cooler switch valve 12 is magnetic valves.This cooler switch valve 12 controlled opening when switching mechanism 3 is in the cooling operation state is in controlled closing when heating operating condition at switching mechanism 3.

Bridge circuit 17 is set at heat source side heat exchanger 4 and utilizes between the side heat exchanger 6, and the reservoir inlet tube 18a that is connected with inlet with reservoir 18 and the reservoir outlet 18b that is connected with the outlet of reservoir 18 connect.In this variation, bridge circuit 17 has 4 check valve 17a, 17b, 17c, 17d.Inlet one-way valve 17a only allows that cold-producing medium is from the flow through check valve of reservoir inlet tube 18a of heat source side heat exchanger 4.Inlet one-way valve 17b only allows that cold-producing medium is from utilizing the flow through check valve of reservoir inlet tube 18a of side heat exchanger 6.That is, inlet one-way valve 17a, 17b have and make cold-producing medium from heat source side heat exchanger 4 and the function of utilizing the reservoir inlet tube 18a that flows through the side heat exchanger 6.Outlet check valve 17c only allows that cold-producing medium is flowed through from reservoir outlet 18b to utilize the check valve of side heat exchanger 6.Outlet check valve 17d only allows that cold-producing medium is from the flow through check valve of heat source side heat exchanger 4 of reservoir outlet 18b.That is, outlet check valve 17c, 17d have and make cold-producing medium from flow through heat source side heat exchanger 4 and utilize another function the side heat exchanger 6 of reservoir outlet 18b.

Reservoir inlet expansion mechanism 5a is provided in a side of the mechanism that being used in the reservoir inlet tube 18 reduced pressure to cold-producing medium, uses electric expansion valve in this variation.In addition, in this variation, when cooling operation, reservoir inlet expansion mechanism 5a is sent to the high-pressure refrigerant that will be cooled in heat source side heat exchanger 4 and it is reduced pressure before utilizing side heat exchanger 6, when the warm running of system, reservoir inlet expansion mechanism 5a reduces pressure to it before the high-pressure refrigerant that will be cooled in utilizing side heat exchanger 6 is sent to heat source side heat exchanger 4.

Reservoir 18 is containers of establishing in order temporarily to be stored in the cold-producing medium after being depressurized among the reservoir inlet expansion mechanism 5a, and its inlet is connected with reservoir inlet tube 18a, and its outlet is connected with reservoir outlet 18b.In addition, reservoir 18 with can the suction recurrent canal 18c of its suction line 2a that returns compressing mechanism 2 (that is, the leading portion side pressure of compressing mechanism 2 contract suction one side of parts 2c) be connected from sucking-off cold-producing mediums in the reservoir 18.In this suction recurrent canal 18c, be provided with and suck Returning switch valve 18d.In this variation, sucking Returning switch valve 18d is magnetic valve.

Reservoir outlet expansion mechanism 5b is the mechanism that being used for of being provided with in reservoir outlet 18 reduced pressure to cold-producing medium, uses electric expansion valve in this variation.In addition, in this variation, when cooling operation, reservoir outlet expansion mechanism 5b will be to being sent to that utilizing continues before the side heat exchanger 6 it is reduced pressure becomes low pressure until it by the enter the mouth cold-producing medium of expansion mechanism 5a decompression of reservoir, when the warm running of system, reservoir outlet expansion mechanism 5b to being sent to continue before the heat source side heat exchanger 4 it is reduced pressure and becoming low pressure until it by the enter the mouth cold-producing medium of expansion mechanism 5a decompression of reservoir.

So, utilize bridge circuit 17, reservoir 18, reservoir inlet tube 18a and reservoir outlet 18b, when switching mechanism 3 becomes the cooling operation state, just the high-pressure refrigerant that can will be cooled in heat source side heat exchanger 4 is sent to it then and utilizes side heat exchanger 6 by reservoir inlet expansion mechanism 5a, reservoir 18, the reservoir outlet expansion mechanism 5b of reservoir outlet 18b and the outlet check valve 17c of bridge circuit 17 of inlet one-way valve 17a, the reservoir inlet tube 18a of bridge circuit 17.In addition, when switching mechanism 3 becomes the heating operating condition, just the high-pressure refrigerant that can will be cooled in utilizing side heat exchanger 6 is sent to it heat source side heat exchanger 6 then by reservoir inlet expansion mechanism 5a, reservoir 18, the reservoir outlet expansion mechanism 5b of reservoir outlet 18b and the outlet check valve 17d of bridge circuit 17 of inlet one-way valve 17b, the reservoir inlet tube 18a of bridge circuit 17.

Rear section side playpipe 19 has to make at heat source side heat exchanger 4 or utilize the cold-producing medium that is cooled in the side heat exchanger 6 to shunt makes it return the function of the rear section side compression member 2d of compressing mechanism 2 then.In this variation, rear section side playpipe 19 makes the mode of its suction one side of returning rear section side compression member 2d then according to the cold-producing medium shunting that makes the reservoir inlet tube 18a that flows through and establishes.More specifically, (that is, when switching mechanism 3 became the cooling operation state, heat source side heat exchanger 4 entered the mouth between the expansion mechanism 5a with reservoir from upper reaches one side position of the reservoir of reservoir 18a inlet expansion mechanism 5a according to rear section side playpipe 19; The person utilizes between side heat exchanger 6 and the reservoir inlet expansion mechanism 5a when switching mechanism 3 becomes heating during operating condition) cold-producing medium is shunted, make then its intercooler that returns intermediate refrigerant pipe 87 a dirty side position mode and establish.In this rear section side playpipe 19, be provided with the rear section side injection valve 19a that can control aperture.In this variation, rear section side injection valve 19a is an electric expansion valve.

Economizer heat exchanger 20 be used at heat source side heat exchanger 4 or utilize the cold-producing medium that is cooled in the side heat exchanger 6 and the rear section side playpipe 19 of flowing through cold-producing medium (more specifically, press in the middle of in rear section side injection valve 19a, being depressurized near after cold-producing medium) heat exchanger that carries out heat exchange.In this variation, economizer heat exchanger 20 is according to upper reaches one side position of the reservoir of the reservoir inlet tube 18a that flows through inlet expansion mechanism 5a (promptly, when switching mechanism 3 becomes cooling operation, between heat source side heat exchanger 4 and the reservoir inlet expansion mechanism 5a; Perhaps when switching mechanism 3 becomes the heating operating condition, utilize between side heat exchanger 6 and the reservoir inlet expansion mechanism 5a) the cold-producing medium of cold-producing medium and the rear section side playpipe 19 of flowing through carry out the mode of heat exchange and establish, have the stream that two cold-producing mediums flow according in opposite directions mode in addition.In addition, in this variation, economizer heat exchanger 20 is set at upper reaches one side of the rear section side playpipe 19 of reservoir inlet tube 18a.Therefore, at heat source side heat exchanger 4 or utilize the cold-producing medium that is cooled in the side heat exchanger 6 in reservoir inlet tube 18a, in economizer heat exchanger 20 by heat exchange before by rear section side playpipe 19 shunting, then, in economizer heat exchanger 20, carry out heat exchange with the cold-producing medium of the rear section side playpipe 19 of flowing through.

And, in the conditioner 1 of this variation, be provided with various sensors.Specifically, in intermediate refrigerant pipe 8 or compressing mechanism 2, be provided with and be used for detecting the intermediate pressure sensor 54 of pressure of cold-producing medium of refrigerant pipe 8 of flowing through.Be provided with the economizer heat exchanger outlet temperature sensor 55 of the temperature of the cold-producing medium in the outlet of rear section side playpipe 19 1 sides that are used for detecting economizer heat exchanger 20 in the outlet of rear section side playpipe 19 1 sides of economizer heat exchanger 20.

Below, use Figure 14～Figure 18, the operation of the aircondition 1 of this variation is described.Herein, Figure 15 is the pressure-enthalpy line chart of the freeze cycle during cooling operation in the variation 6, Figure 16 is the temperature-entropy line chart of the freeze cycle during cooling operation in the variation 6, Figure 17 is the pressure-enthalpy line chart of the freeze cycle when system warms up running in the variation 6, and Figure 18 is the temperature-entropy line chart of the freeze cycle when system warms up running in the variation 6.In addition, following cooling operation is undertaken by above-mentioned control part (not shown) with the running control in the warm running of system.In addition, in the following description, high pressure in " high pressure " expression freeze cycle (promptly, pressure among pressure among some D among Figure 15,16, D ', E, the H and the some D among Figure 17,18, D ', F, the H), low pressure in " low pressure " expression freeze cycle (promptly, some A among Figure 15,16, the pressure among F, the F ' and the some A among Figure 17,18, the pressure among E, the E '), press (that is the pressure among the some B1 in Figure 15～18, C1, G, J, the K) in the middle of in " the middle pressure " expression freeze cycle.

(cooling operation)

When cooling operation, switching mechanism 3 is in the cooling operation state shown in the solid line of Figure 14.The aperture of reservoir inlet expansion mechanism 5a and reservoir outlet expansion mechanism 5b is conditioned.Because switching mechanism 3 becomes the cooling operation state, therefore, cooler switch valve 12 is opened, and perhaps the intercooler bypass cock valve 11 of intercooler bypass pipe 9 is closed, so intercooler 7 just becomes can be as the state of cooler.And the aperture of rear section side injection valve 19a also is conditioned.More specifically, in this variation, implement so-called degree of superheat control, the aperture of regulating rear section side injection valve 19a is so that the degree of superheat of the cold-producing medium of the outlet that is arranged in rear section side playpipe 19 1 sides of economizer heat exchanger 20 reaches desired value.In this variation, the degree of superheat of the cold-producing medium of the outlet that is arranged in rear section side playpipe 19 1 sides of economizer heat exchanger 20 obtains by the following method: will by intermediate pressure sensor 54 detected come in the middle of press and be converted into saturation temperature, from by the saturation temperature value that deducts this cold-producing medium the detected refrigerant temperature of coming of economizer exit temperature sensor 55.In addition, in this variation, do not adopt, but, also can temperature sensor be set at the inlet that is positioned at rear section side playpipe 19 1 sides of economizer heat exchanger 20, from economizer exit temperature sensor 55 detected next refrigerant temperatures, deduct by the detected next refrigerant temperature of this temperature sensor, thus the degree of superheat of the cold-producing medium of the outlet that is arranged in rear section side playpipe 19 1 sides of acquisition economizer heat exchanger 20.

If drive compression mechanism 2 under the state of this refrigerant line 310, so, low pressure refrigerant (with reference to the some A among Figure 14～Figure 16) is inhaled into the compressing mechanism 2 from suction line 2a, at first, be compressed after parts 2c is compressed to intermediate pressure, be discharged to intermediate refrigerant pipe 8 (with reference to the some B1 among Figure 14～Figure 16).Same with above-mentioned embodiment, during oil content was disembarked the middle oil eliminator 16a of structure 16 in the middle of the compacting cryogen flow into to constitute in the middle of being discharged from, after the refrigerator oil of Liu Ruing is separated with it, be sent to intercooler 7 from parts 2c is contracted in this leading portion side pressure.In addition, oil content was disembarked among the middle oil return pipe 16b of structure 16 in the middle of the refrigerator oil that is separated from centre compacting cryogen in middle oil eliminator 16a flowed into and constitutes, return compressing mechanism 2 (being suction line 2a) herein after the mechanism of decompressor 16c decompression in the middle of being arranged among the oil return pipe 16b, sucked once more in the compressing mechanism 2.Then, in middle oil content is disembarked structure 16 refrigerator oil by compacting cryogen in the middle of after wherein separate, thereby in intercooler 7 with carry out heat exchange be cooled (with reference to the some C1 among Figure 14～Figure 16) as the water of cooling source or air.The cold-producing medium that is cooled in this intercooler 7 is further cooled (with reference to the some G among Figure 14～Figure 16) after converging with the cold-producing medium (with reference to the some K Figure 14～Figure 16) that returns rear section side compression member 2d from rear section side playpipe 19.Then, be inhaled into the compression member 2d that is connected with the rear section side of compression member 2c with the middle compacting cryogen after the cold-producing medium that returns from rear section side playpipe 19 converges, further compressed then, be discharged to discharge pipe 2b (with reference to the some D Figure 14～Figure 16) from compressing mechanism 2.Herein, the high-pressure refrigerant that is discharged from from compressing mechanism 2 is according to the secondary squeeze operation of compression member 2c, 2d, is compressed the pressure that becomes above critical pressure (that is the critical pressure Pcp among the critical point CP shown in Figure 15).Then, the high-pressure refrigerant that is discharged from from this compressing mechanism 2 is via switching mechanism 3, being sent to can be as the heat source side heat exchanger 4 of the cooler of cold-producing medium, carries out heat exchange with water or air as cooling source then, thereby is cooled (with reference to the some E among Figure 14～Figure 16).The high-pressure refrigerant that is cooled in heat source side heat exchanger 4 is by flowing into reservoir inlet tube 18a behind the inlet one-way valve 17a of bridge circuit 17, its part is by 19 shuntings of rear section side playpipe.After near pressing in the middle of the cold-producing medium of rear section side playpipe 19 of flowing through is depressurized and becomes, be sent to economizer heat exchanger 20 (with reference to the some J among Figure 14～Figure 16) in rear section side injection valve 19a.In addition, flowed into economizer heat exchanger 20, with the cold-producing medium of the rear section side playpipe 19 of flowing through carry out being cooled after the heat exchange (with reference to the some H among Figure 14～Figure 16) by the cold-producing medium of the reservoir inlet tube 18a that flows through after rear section side playpipe 19 shunting.The cold-producing medium of rear section side playpipe 19 of flowing through carries out being heated after the heat exchange (with reference to the some K among Figure 14～Figure 16) with the cold-producing medium of reservoir inlet tube 18a of flowing through, and then as mentioned above, converges with the cold-producing medium that is cooled in intercooler 7.The high-pressure refrigerant that is cooled in economizer heat exchanger 20 is decompressed near the saturation pressure by reservoir inlet expansion mechanism 5a, temporarily is stored in then in the reservoir 18 (with reference to the some I among Figure 14～Figure 16).The cold-producing medium that is stored in the reservoir 18 is sent to reservoir outlet 18b, become the cold-producing medium of the gas-liquid two-phase state of low pressure after the reservoir outlet expansion mechanism 5b decompression, be sent to behind the outlet check valve 17c by bridge circuit 17 can be as the heater of cold-producing medium utilize square heat-exchanger 6 (with reference to the some F among Figure 14～Figure 16).Then, be sent to the low pressure of utilizing square heat-exchanger 6 the gas-liquid two-phase state cold-producing medium with carry out being heated after the heat exchange evaporation (with reference to the some A among Figure 14～Figure 16) then as the water or the air of heating source.Utilize at this that heated low pressure refrigerant is sucked compressing mechanism 2 once more via switching mechanism 3 in square heat-exchanger 6.Adopt aforesaid way to carry out cooling operation.

In the structure of this variation, same with above-mentioned embodiment, in the cooling operation when switching mechanism 3 becomes the cooling operation state, intercooler 7 is become can be as the state of cooler, therefore, compare with the situation that intercooler 7 is not set, so just can reduce the radiation loss in the heat source side heat exchanger 4.

In addition, in the structure of this variation, same with above-mentioned embodiment, because the part between the inlet of the compression member 2c of the leading portion side of intermediate refrigerant pipe 8 and intercooler 7 is provided with the centre oil content structure 16 of disembarking, therefore, not only can prevent to cause the machine oil of compressing mechanism 2 to exhaust in the intercooler 7, and can prevent that the heat transfer property of intercooler 7 from descending or pressure loss increase because of refrigerator oil accumulates in.And in this variation, structure 16 is set up than the position of intermediate refrigerant pipe 8 with the more close upper reaches of connecting portion one side of intercooler bypass pipe 9 because middle oil content is disembarked, and therefore, can prevent that refrigerator oil from accumulating in the intercooler bypass pipe 9.

And, in the structure of this distortion, rear section side playpipe 19 is set, the cold-producing medium that is sent to expansion mechanism 5a, 5b from heat source side heat exchanger 4 is shunted, make it return rear section side compression member 5d then, therefore, to outside heat radiation such as intercooler 7 grades, thereby the temperature that can further suppress to be inhaled into the cold-producing medium among the rear section side compression member 5d descends (with reference to some C1, the G among Figure 16).Like this, the temperature of the cold-producing medium that is discharged from from compressing mechanism 2 descends and is further suppressed (with reference to some D, the D ' among Figure 16), compare with the situation that rear section side playpipe 19 is not set, the radiation loss of the area size that the some C1, D ', D, the G that are equivalent to link among Figure 16 constituted can be further reduced, therefore running efficiency can be further improved.

In addition, in the structure of this variation, owing to also be provided with to being sent to expansion mechanism 5a from heat source side heat exchanger 4, the economizer heat exchanger 20 that the cold-producing medium of the cold-producing medium of 5b and the rear section side playpipe 19 of flowing through carries out heat exchange, therefore, the flow through cold-producing medium of rear section side playpipe 19 of utilization just can cool off from heat source side heat exchanger 4 and is sent to expansion mechanism 5a, the cold-producing medium of 5b is (with reference to Figure 15, some E among Figure 16, point H), with the situation that rear section side playpipe 19 and economizer heat exchanger 20 are not set (in the case, at Figure 15, among Figure 16, order according to an an an an an an A → B1 → C1 → D ' → E → F ' is carried out freeze cycle) compare, can improve the refrigerating capacity of the specific discharge that utilizes the cold-producing medium in the square heat-exchanger 6.

(heating running)

When heating running, switching mechanism 3 becomes the operating condition that heats shown in the dotted line of Figure 14.The aperture of reservoir inlet expansion mechanism 5a and reservoir outlet expansion mechanism 5b is conditioned.Because switching mechanism 3 becomes and heats operating condition, therefore, cooler switch valve 12 is closed, and perhaps the intercooler bypass cock valve 11 of intercooler bypass pipe 9 is opened, so intercooler 7 just becomes can not be as the state of cooler.And, also identical degree of superheat control by with cooling operation time of rear section side injection valve 19a, its aperture also is conditioned.

If drive compression mechanism 2 under the state of this refrigerant line 310, so, low pressure refrigerant (with reference to the some A among Figure 14, Figure 17, Figure 18) is inhaled into the compressing mechanism 2 from suction line 2a, at first, be compressed after parts 2c is compressed to intermediate pressure, be discharged to intermediate refrigerant pipe 8 (with reference to the some B1 among Figure 14, Figure 17, Figure 18).Same with above-mentioned embodiment, during oil content was disembarked the middle oil eliminator 16a of structure 16 in the middle of the compacting cryogen flow into to constitute in the middle of being discharged from, after the refrigerator oil of Liu Ruing is separated with it, be sent to intercooler 7 from parts 2c is contracted in this leading portion side pressure.In addition, oil content was disembarked among the middle oil return pipe 16b of structure 16 in the middle of the refrigerator oil that is separated from centre compacting cryogen in middle oil eliminator 16a flowed into and constitutes, return compressing mechanism 2 (being suction line 2a) herein after the mechanism of decompressor 16c decompression in the middle of being arranged among the oil return pipe 16b, sucked once more in the compressing mechanism 2.Then, different during with cooling operation, refrigerator oil is not by compacting cryogen in the middle of after wherein separate not by intercooler 7 (promptly in middle oil content is disembarked structure 16, be not cooled), but by intercooler bypass pipe 9 (with reference to the some C1 among Figure 14, Figure 17, Figure 18), with the cold-producing medium that returns rear section side compressing mechanism 2d from rear section side playpipe 19 (with reference to the some K Figure 14, Figure 17, Figure 18) thus converge be cooled (with reference to the some G among Figure 14, Figure 17, Figure 18).Then, be inhaled into the compression member 2d that is connected with the rear section side of compression member 2c with the middle compacting cryogen after the cold-producing medium that returns from rear section side playpipe 19 converges, further compressed then, be discharged to discharge pipe 2b (with reference to the some D Figure 14, Figure 17, Figure 18) from compressing mechanism 2.Herein, same during with cooling operation, the high-pressure refrigerant that is discharged from from compressing mechanism 2 is according to the secondary squeeze operation of compression member 2c, 2d, is compressed the pressure that becomes above critical pressure (that is the critical pressure Pcp among the critical point CP shown in Figure 17).Then, the high-pressure refrigerant that is discharged from from this compressing mechanism 2 is via switching mechanism 3, be sent to can as the cooler of cold-producing medium utilize square heat-exchanger 6, carry out heat exchange with water or air then, thereby be cooled (with reference to the some F among Figure 14, Figure 17, Figure 18) as cooling source.The high-pressure refrigerant that is cooled in utilizing square heat-exchanger 6 is by flowing into reservoir inlet tube 18a behind the inlet one-way valve 17b of bridge circuit 17, its part is by 19 shuntings of rear section side playpipe.After near pressing in the middle of the cold-producing medium of rear section side playpipe 19 of flowing through is depressurized and becomes, be sent to economizer heat exchanger 20 (with reference to the some J among Figure 14, Figure 17, Figure 18) in rear section side injection valve 19a.In addition, flowed into economizer heat exchanger 20, with the cold-producing medium of the rear section side playpipe 19 of flowing through carry out being cooled after the heat exchange (with reference to the some H among Figure 14, Figure 17, Figure 18) by the cold-producing medium of the reservoir inlet tube 18a that flows through after rear section side playpipe 19 shunting.The cold-producing medium of rear section side playpipe 19 of flowing through carries out being heated after the heat exchange (with reference to the some K among Figure 14, Figure 17, Figure 18) with the cold-producing medium of reservoir inlet tube 18a of flowing through, then as mentioned above, with the parts 2c that contracts from the leading portion side pressure be discharged from the middle of the compacting cryogen converge.The high-pressure refrigerant that is cooled in economizer heat exchanger 20 is decompressed near the saturation pressure by reservoir inlet expansion mechanism 5a, temporarily is stored in then in the reservoir 18 (with reference to the some I among Figure 14, Figure 17, Figure 18).The cold-producing medium that is stored in the reservoir 18 is sent to reservoir outlet 18b, become the cold-producing medium of the gas-liquid two-phase state of low pressure after the reservoir outlet expansion mechanism 5b decompression, be sent to the heat source side heat exchanger 4 (with reference to the some E among Figure 14, Figure 17, Figure 18) that can be used as the heater of cold-producing medium behind the outlet check valve 17d by bridge circuit 17.Then, be sent to heat source side heat exchanger 4 low pressure the gas-liquid two-phase state cold-producing medium with carry out being heated after the heat exchange evaporation (with reference to the some A among Figure 14, Figure 17, Figure 18) then as the water or the air of heating source.Heated low pressure refrigerant is sucked in the compressing mechanism 2 once more via switching mechanism 3 in this heat source side heat exchanger 4.Adopt aforesaid way to heat running.

In the structure of this variation, become at switching mechanism 3 and to heat heating in the running under the operating condition, close cooler switch valve 12, perhaps open the intercooler bypass cock valve 11 of intercooler bypass pipe 9, so, intercooler 7 just becomes can not be as the state of cooler, therefore, with the situation that only is provided with intercooler 7 and with above-mentioned cooling operation intercooler 7 can be compared as the situation of cooler, the temperature of the cold-producing medium that from compressing mechanism 2, is discharged from be inhibited (with reference to some D, the D ' among Figure 18) that descend.Therefore, in this aircondition 1, with the situation that only is provided with intercooler 7 and with above-mentioned cooling operation intercooler 7 can be compared as the situation of cooler, not only can suppress heat radiation to the outside, the temperature that inhibition is supplied to the cold-producing medium that utilizes square heat-exchanger 6 of the cooler that can be used as cold-producing medium descends, and can suppress the decline of heating efficiency, thereby can prevent that running efficiency from reducing.

In addition, in the structure of this variation, same during with above-mentioned cooling operation, because the oil content structure 16 of disembarking in the middle of the part between the inlet of the compression member 2c of the leading portion side of intermediate refrigerant pipe 8 and intercooler 7 is provided with, therefore, not only can prevent to cause the machine oil of compressing mechanism 2 to exhaust in the intercooler 7, and can prevent that the heat transfer property of intercooler 7 from descending or pressure loss increase because of refrigerator oil accumulates in.

And, in the structure of this variation, because rear section side playpipe 19 is set, to from utilizing square heat-exchanger 6 to be sent to expansion mechanism 5a, after shunting, the cold-producing medium of 5b make it return rear section side compression member 5d, therefore, the temperature step-down of the cold-producing medium of discharging from compressing mechanism 2 is (with reference to the some D Figure 18, point D '), so, utilize the heating capacity of the specific discharge of the cold-producing medium in the square heat-exchanger 6 to diminish (with reference to the some D among Figure 17, point D ', point F), but, owing to the flow of the cold-producing medium of discharging from rear section side compression member 2d increases, therefore, the heating capacity in the square heat-exchanger 6 can be guaranteed to utilize, thereby running efficiency can be improved.

In addition, in the structure of this variation, owing to also be provided with from utilizing square heat-exchanger 6 to be sent to expansion mechanism 5a, the economizer heat exchanger 20 that the cold-producing medium of the cold-producing medium of 5b and the rear section side playpipe 19 of flowing through carries out heat exchange, therefore, utilization is sent to expansion mechanism 5a from utilizing square heat-exchanger 6, the cold-producing medium of 5b just can heat the cold-producing medium of the rear section side playpipe 19 of flowing through (with reference to Figure 17, some J among Figure 18, point K), with the situation that rear section side playpipe 19 and economizer heat exchanger 20 are not set (in the case, at Figure 17, among Figure 18, order according to an an an an an an A → B1 → C1 → D ' → F → E ' is carried out freeze cycle) compare, can increase the flow of the cold-producing medium of from rear section side compression member 2d, discharging.

In addition, the common advantage of cooling operation and the warm running of system is, in the structure of this variation, adopted as economizer heat exchanger 20 and a kind ofly to have had from heat source side heat exchanger 4 or utilize side heat exchanger 6 to be sent to expansion mechanism 5a, the heat exchanger of the stream that the cold-producing medium of the cold-producing medium of 5b and the rear section side playpipe 19 of flowing through is flowed through according to relative mode, therefore, not only can dwindle the heat source side heat exchanger 4 from economizer heat exchanger 20 or utilize side heat exchanger 6 to be sent to expansion mechanism 5a, the temperature difference of the cold-producing medium of the cold-producing medium of 5b and the rear section side playpipe 19 of flowing through, and can obtain high heat exchanger effectiveness.In addition, in the structure of this variation, from heat source side heat exchanger 4 or utilize side heat exchanger 6 to be sent to expansion mechanism 5a, the cold-producing medium of 5b in economizer heat exchanger 20 by heat exchange before, make from heat source side heat exchanger 4 or utilize side heat exchanger 6 to be sent to expansion mechanism 5a, the cold-producing medium shunting of 5b, be provided with rear section side playpipe 19 in this manner, therefore, not only can reduce in economizer heat exchanger 20 cold-producing medium with the rear section side playpipe 19 of flowing through carry out heat exchange from heat source side heat exchanger 4 or utilize side heat exchanger 6 to be sent to expansion mechanism 5a, the flow of the cold-producing medium of 5b, reduce the heat-shift in the economizer heat exchanger 20, and can dwindle the size of economizer heat exchanger 20.

In addition, omit its detailed explanation herein, but, the compressing mechanism 2 that both can replace two stage compression types, (for example adopt as three stage compression types, the compressing mechanism 102 in the variation 3) the multi-stage compression mechanism of Duoing than two stage compression types like that such as, perhaps, the compressing mechanism 2 that also can replace two stage compression types, as form and adopted compressing mechanism 203 with two stage compression types in the variation 4, the refrigerant lines 410 (with reference to Figure 19) of 204 compressing mechanism 202 etc. are such, the be connected in parallel compressing mechanism of multi-stage compression formula arranged side by side of compressing mechanism of a plurality of systems of employing in the case, also can obtain the effect identical with this variation.In addition, in the aircondition 1 of this variation, no matter be when cooling operation or when heating running, all make cold-producing medium towards reservoir inlet expansion mechanism 5a, reservoir outlet expansion mechanism 5b, reservoir 18, rear section side playpipe 19, perhaps the flow direction of economizer heat exchanger 20 is fixed, based on this viewpoint, adopted bridge circuit 17 simultaneously, for example, only when cooling operation or under the operating condition in heating when turning round, use rear section side playpipe 19 and economizer heat exchanger 20, no matter be when cooling operation or heat when running, all needn't make cold-producing medium towards reservoir inlet expansion mechanism 5a, reservoir outlet expansion mechanism 5b, reservoir 18, rear section side playpipe 19, perhaps the flow direction of economizer heat exchanger 20 is fixed, in the case, also can omit bridge circuit 17.

(9) variation 7

In the refrigerant line 310 (with reference to Figure 14) and refrigerant line 410 (with reference to Figure 19) in above-mentioned variation 6, adopt and connect a structure that utilizes square heat-exchanger 6, but, also can adopt to connect a plurality of square heat-exchangers 6 that utilize, and can start separately and stop the structure that these utilize square heat-exchanger 6.

As shown in figure 20, in the refrigerant line 310 of the variation 7 of the compressing mechanism 2 that has adopted two stage compression types (with reference to Figure 15), connect 2 and utilize square heat-exchanger 6, and utilize the corresponding side of the utilization expansion mechanism 5c that is provided with of bridge circuit 17 sides of square heat-exchanger 6 with each, deletion set reservoir in reservoir outlet 18b exports expansion mechanism 5b, and, replace the outlet check valve 17d of bridge circuit 17 and bridge outlet expansion mechanism 5d is set, form refrigerant line 510, perhaps as shown in figure 21, in the refrigerant line 410 (with reference to Figure 19) of the variation 6 of the compressing mechanism 202 that has adopted two stage compression types arranged side by side, connect 2 and utilize square heat-exchanger 6, and utilize the corresponding side of the utilization expansion mechanism 5c that is provided with of bridge circuit 17 sides of square heat-exchanger 6 with each, deletion set reservoir in reservoir outlet 18b exports expansion mechanism 5b, and, replace the outlet check valve 17d of bridge circuit 17 and bridge outlet expansion mechanism 5d is set, form refrigerant line 610.

In the structure of this variation, bridge outlet expansion mechanism 5d becomes complete closing state this point when cooling operation, and the reservoir that replaces in the variation 7 exports expansion mechanism 5b, by the side of utilization expansion mechanism 5c implementation and operation, to being sent to and continuing its decompression until becoming the low pressure this point before utilizing square heat-exchanger 6 by the reservoir post-decompression cold-producing medium of expansion mechanism 5a that enters the mouth, operation during with cooling operation in the variation 6 is different, for other operation, the operation (with reference to Figure 14～Figure 16 and relevant record thereof) during with cooling operation in the variation 6 is basic identical.In addition, when heating running, flow through in order to control that each utilizes the flow of cold-producing medium of square heat-exchanger 6 and the aperture this point of regulating the side of utilization expansion mechanism 5c, and the reservoir that replaces in the variation 6 exports expansion mechanism 5b, by bridge outlet expansion mechanism 5d implementation and operation, to being continued its decompression until becoming the low pressure this point before being sent to heat source side heat exchanger 4 by the reservoir post-decompression cold-producing medium of expansion mechanism 5a that enters the mouth, operation when turning round with heating in the variation 6 is different, for other operation, the operation (Figure 14 when turning round with heating in the variation 6, Figure 17, Figure 18 and relevant record thereof) basic identical.

In the structure of this variation, also can obtain the action effect identical with above-mentioned variation 6.

In addition, omit detailed explanation herein, still, also can replace the compressing mechanism 2,203,204 of two stage compression types, adopt the many multi-stage compression mechanisms of three stage compression types (for example, the compressing mechanism 102 in the variation 3) geometric ratio two stage compression types.

(10) other embodiment

More than, with reference to the accompanying drawings, embodiments of the present invention and variation thereof are illustrated, still, concrete structure is not limited to these embodiments and variation thereof, can change in the scope that does not break away from inventive concept.

For example, in above-mentioned embodiment and variation thereof, use and to carry out the heating source of heat exchange with the cold-producing medium that utilizes side heat exchanger 6 of flowing through or as the water or the salt solution of cooling source, and the secondary heat exchanger that is provided with and is carried out heat exchange by the water of heat exchange or salt solution and room air in utilizing side heat exchanger 6, the present invention also can be applicable in the conditioner of this set type.

In addition, even the refrigerating plant of other type of the conditioner of above-mentioned set type, can switch cooling operation and the warm refrigerant loop that turns round of system as long as have, the cold-producing medium that use is worked in supercritical region carries out multi-stage compression formula freeze cycle then as cold-producing medium, also can use the present invention.

In addition, be not to be defined in carbon dioxide as the cold-producing medium of in supercritical region, working, also can use ethene, ethane and nitrogen oxide etc.

In addition, even the refrigerating plant of other type of the aircondition of above-mentioned set type as long as use the cold-producing medium of working to carry out multi-stage compression formula freeze cycle as cold-producing medium, so just can be used the present invention in supercritical region.

In addition, be not to be defined in carbon dioxide as the cold-producing medium of in supercritical region, working, also can use ethene, ethane and nitrogen oxide etc.

Industrial applicibility

If utilize the present invention, using the cold-producing medium in supercritical region work to carry out in the tourelle of multi-stage compression formula freeze cycle, can prevent that the machine oil of compressing mechanism from exhausting.

Claims (4)

1. refrigerating plant, it uses the cold-producing medium of working in supercritical region, and this refrigerating plant (1) is characterised in that, comprising:

Compressing mechanism (2,102,202), it has a plurality of compression member, compresses leading portion side pressure from the described a plurality of compression member cold-producing medium that parts discharge that contracts successively with the rear section side compression member;

Heat source side heat exchanger (4);

The expansion mechanism that cold-producing medium is reduced pressure (5,5a, 5b, 5c, 5d);

Utilize side heat exchanger (6);

Intercooler (7), it is set at the intermediate refrigerant pipe (8) that is used for the cold-producing medium that the parts that contract from described leading portion side pressure are discharged is sucked described rear section side compression member, is inhaled into the cooler of the cold-producing medium the described rear section side compression member as contract the parts discharge from described leading portion side pressure; With

The middle oil content structure (16) of disembarking, its described leading portion side pressure that is set at described intermediate refrigerant pipe part between the inlet of parts and described intercooler that contracts will be separated from cold-producing medium and makes it turn back to described compressing mechanism from contract refrigerator oil that parts are discharged from cold-producing medium of described leading portion side pressure.

2. refrigerating plant as claimed in claim 1 (1) is characterized in that:

The oil content structure (16) of disembarking comprising in the middle of described: will be from the described leading portion side pressure middle oil eliminator (16a) that refrigerator oil that parts are discharged from cold-producing medium separates from cold-producing medium that contracts; With with described in the middle of oil eliminator be connected, be used for making the refrigerator oil of from cold-producing medium, separating to turn back to the middle oil return pipe (16b) of compressing mechanism (2,102,202).

3. refrigerating plant as claimed in claim 1 (1) is characterized in that:

The oil content structure (16) of disembarking comprising in the middle of described: the header box (16d) that is provided with at the inlet of described intercooler (7); Be used for being connected the lower end of described header box and the middle oil return pipe (16b) of described compressing mechanism (2,102,202).

4. as each described refrigerating plant (1) in the claim 1～3, it is characterized in that:

Described cold-producing medium of working in supercritical region is a carbon dioxide.

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