JP2015102319A5

JP2015102319A5 -

Info

Publication number: JP2015102319A5
Application number: JP2013245943A
Authority: JP
Filing date: 2013-11-28
Publication date: 2016-08-12
Anticipated expiration: 2033-11-28

Description

このとき、凝縮器４と主膨張弁５との間から高圧低温の液冷媒の一部が第１分岐配管１１及び第２分岐配管１２を介して中間圧室２ｃに液インジェクションされる。一方、油分離器３の冷凍機油は、高段側返油配管２２から直接高段側圧縮部２ｂ側に返油され、低段側返油配管２１から油冷却器３０を介して低段側圧縮部２ａに返油される。この油冷却器３０において、第２分岐配管１２を流れる冷媒と、低段側返油配管２１を流れる冷凍機油とが熱交換され、冷凍機油が冷却された状態で低段側圧縮部２ａに返油される。この際、高段側圧縮部２ｂから吐出される冷媒の吐出ガス温度が目標吐出温度（例えば８５℃）になるように、開度制御部４０により第１流量調整器１３及び第２流量調整器１４の開度が制御される。 At this time, a part of the high-pressure and low-temperature liquid refrigerant is injected into the intermediate pressure chamber 2 c through the first branch pipe 11 and the second branch pipe 12 from between the condenser 4 and the main expansion valve 5. On the other hand, the refrigerating machine oil of the oil separator 3 is returned directly from the high- stage oil return pipe 22 to the high -stage compression section 2b, and from the low-stage oil return pipe 21 through the oil cooler 30 to the low-stage side. Oil is returned to the compression section 2a. In this oil cooler 30, the refrigerant flowing through the second branch pipe 12 and the refrigerating machine oil flowing through the low-stage oil return pipe 21 are heat-exchanged and returned to the low-stage compression section 2a in a state where the refrigerating machine oil is cooled. Oiled. At this time, the opening degree control unit 40 causes the first flow rate regulator 13 and the second flow rate regulator so that the discharge gas temperature of the refrigerant discharged from the high stage compression unit 2b becomes a target discharge temperature (for example, 85 ° C.). The opening of 14 is controlled.

Claims

A refrigeration cycle circuit having a compressor, a condenser, and an expansion valve is provided, and the compressor discharges a low-stage compression unit that compresses the refrigerant, and a refrigerant compressed in the low-stage compression unit. A refrigeration cycle apparatus comprising an intermediate pressure chamber, and a high-stage compression unit that sucks and compresses the refrigerant in the intermediate pressure chamber,
An oil separator that is installed between a discharge side of the compressor and the condenser, and separates a refrigerant discharged from the high-stage compression unit and a refrigerating machine oil contained in the refrigerant;
An oil return flow path for returning the refrigeration oil separated in the oil separator to the low-stage compression section and the high-stage compression section;
An injection flow path for injecting refrigerant flowing out of the condenser into the intermediate pressure chamber;
An oil cooler that exchanges heat between refrigerating machine oil flowing through the oil return passage and refrigerant flowing through the injection passage,
The injection flow path is
A first branch pipe for injecting refrigerant directly from the condenser into the intermediate pressure chamber;
And a second branch pipe for injecting a refrigerant from the condenser to the intermediate pressure chamber through the oil cooler.

A first flow rate regulator that is provided in the first branch pipe and adjusts a flow rate of refrigerant flowing in the first branch pipe;
2. The refrigeration cycle apparatus according to claim 1, further comprising: a second flow rate regulator that is provided in the second branch pipe and adjusts a flow rate of the refrigerant flowing in the second branch pipe.

An opening degree control unit that controls the opening degree of the first flow rate regulator or the second flow rate regulator so that the discharge gas temperature of the refrigerant discharged from the high-stage compression unit becomes a set target discharge temperature. The refrigeration cycle apparatus according to claim 2, further comprising:

The oil return flow path includes a high-stage oil return pipe that returns the refrigerating machine oil directly from the oil separator to the high-stage compression unit, and the refrigerating machine oil from the oil separator via the oil cooler. refrigeration cycle apparatus according to any one of claims 1 to 3, characterized in that it has a low-stage oil return pipe to the oil return to the low-stage compressing section.

The oil return flow path includes a low-stage oil return pipe that branches the refrigerating machine oil that has passed through the oil cooler from the oil separator and returns oil to the low-stage compression section and the high-stage compression section, respectively. The refrigeration cycle apparatus according to any one of claims 1 to 3, further comprising a high-stage oil return pipe .

A sub-expansion valve for expanding a part of the refrigerant flowing out of the condenser;
An economizer that further flows out into the first branch pipe and the second branch pipe after heat exchange is performed between the refrigerant expanded by the sub-expansion valve and the refrigerant that has flowed out of the condenser. The refrigeration cycle apparatus according to any one of claims 1 to 5.

The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the compressor is driven by an inverter.

The refrigeration cycle apparatus according to any one of claims 1 to 7, wherein the refrigerant is made of R32 or R410A.