JP2001108308A - Supercritical refrigerating cycle - Google Patents
Supercritical refrigerating cycleInfo
- Publication number
- JP2001108308A JP2001108308A JP28720499A JP28720499A JP2001108308A JP 2001108308 A JP2001108308 A JP 2001108308A JP 28720499 A JP28720499 A JP 28720499A JP 28720499 A JP28720499 A JP 28720499A JP 2001108308 A JP2001108308 A JP 2001108308A
- Authority
- JP
- Japan
- Prior art keywords
- refrigerant
- pressure
- control valve
- heat exchanger
- pressure control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
- F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
- F25B9/008—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being carbon dioxide
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2309/00—Gas cycle refrigeration machines
- F25B2309/06—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
- F25B2309/061—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide with cycle highest pressure above the supercritical pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
- F25B2341/06—Details of flow restrictors or expansion valves
- F25B2341/063—Feed forward expansion valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/17—Control issues by controlling the pressure of the condenser
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B40/00—Subcoolers, desuperheaters or superheaters
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Air-Conditioning For Vehicles (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、高圧側の冷媒圧力
が冷媒の臨界圧力以上となる蒸気圧縮式冷凍サイクル
(本明細書では、超臨界冷凍サイクルと呼ぶ。)に関す
るもので、二酸化炭素を冷媒とする超臨界冷凍サイクル
に適用して有効である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor compression refrigeration cycle (herein, referred to as a supercritical refrigeration cycle) in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. It is effective when applied to a supercritical refrigeration cycle using a refrigerant.
【0002】[0002]
【従来の技術】出願人は、放熱器を流出した冷媒と蒸発
器を流出した冷媒とを熱交換することにより超臨界冷凍
サイクルの成績係数及び冷凍能力の向上を図ったもの
(特願平11−31776号)を既に出願している。2. Description of the Related Art The applicant has attempted to improve the coefficient of performance and refrigeration capacity of a supercritical refrigeration cycle by exchanging heat between a refrigerant flowing out of a radiator and a refrigerant flowing out of an evaporator (Japanese Patent Application No. Hei 11 (1999)). No. 31776) has already been filed.
【0003】[0003]
【発明が解決しようとする課題】しかし、上記出願で
は、放熱器を流出した高圧側の冷媒を、一旦、圧力制御
弁の感温部に導いた後に内部熱交換器に向けて流出させ
て蒸発器を流出した低圧側の冷媒と熱交換させ、その
後、内部熱交換器にて熱交換を終えた高圧側の冷媒を、
再び圧力制御弁に導いて減圧するといった構成としてい
たので、冷媒配管の経路が複雑になるという問題を有し
ていた。However, in the above-mentioned application, the refrigerant on the high-pressure side flowing out of the radiator is once led to the temperature sensing portion of the pressure control valve and then discharged toward the internal heat exchanger to evaporate. Heat exchange with the low-pressure side refrigerant that has flowed out of the vessel, and then the high-pressure side refrigerant that has completed heat exchange in the internal heat exchanger,
Since the pressure was reduced by being led to the pressure control valve again, there was a problem that the route of the refrigerant pipe became complicated.
【0004】本発明は、上記点に鑑み、超臨界冷凍サイ
クルの成績係数及び冷凍能力の向上を図りつつ、冷媒配
管の経路を単純化することを目的とする。[0004] In view of the above, it is an object of the present invention to simplify the route of a refrigerant pipe while improving the coefficient of performance and refrigeration capacity of a supercritical refrigeration cycle.
【0005】[0005]
【課題を解決するための手段】本発明は、上記目的を達
成するために、請求項1に記載の発明では、冷媒を圧縮
する圧縮機(100)と、圧縮機(100)から吐出す
る冷媒を冷却するとともに、内部の圧力が冷媒の臨界圧
力以上となる放熱器(200)と、放熱器(200)か
ら流出する冷媒を減圧するとともに、高圧側の冷媒圧力
を制御する圧力制御弁(300)と、圧力制御弁(30
0)にて減圧された冷媒を蒸発させる蒸発器(400)
と、蒸発器(400)から流出する低圧側の冷媒と圧力
制御弁(300)にて減圧される前の高圧側の冷媒との
間で熱交換を行う内部熱交換器(600)とを備え、圧
力制御弁(300)は、内部熱交換器(600)を流出
した冷媒の温度に基づいて高圧側の冷媒圧力を制御する
ことを特徴とする。In order to achieve the above object, according to the present invention, a compressor (100) for compressing a refrigerant and a refrigerant discharged from the compressor (100) are provided. And a pressure control valve (300) for reducing the pressure of the refrigerant flowing out of the radiator (200) and controlling the pressure of the refrigerant on the high pressure side. ) And a pressure control valve (30
Evaporator (400) for evaporating the refrigerant decompressed in 0)
And an internal heat exchanger (600) for performing heat exchange between the low-pressure side refrigerant flowing out of the evaporator (400) and the high-pressure side refrigerant before being depressurized by the pressure control valve (300). The pressure control valve (300) controls the refrigerant pressure on the high pressure side based on the temperature of the refrigerant flowing out of the internal heat exchanger (600).
【0006】これにより、圧力制御弁(300)にて冷
媒温度を感知させるために、一旦、冷媒を圧力制御弁
(300)に流入させた後に内部熱交換器(600)に
流入させる必要がないので、冷媒配管の経路を簡略化す
ることができる。Accordingly, it is not necessary to flow the refrigerant once into the pressure control valve (300) and then into the internal heat exchanger (600) in order to allow the pressure control valve (300) to sense the refrigerant temperature. Therefore, the route of the refrigerant pipe can be simplified.
【0007】請求項2に記載の発明では、冷媒を圧縮す
る圧縮機(100)と、圧縮機(100)から吐出する
冷媒を冷却するとともに、内部の圧力が冷媒の臨界圧力
以上となる放熱器(200)と、放熱器(200)から
流出する冷媒を減圧するとともに、高圧側の冷媒圧力を
制御する圧力制御弁(300)と、圧力制御弁(30
0)にて減圧された冷媒を蒸発させる蒸発器(400)
と、蒸発器(400)から流出する低圧側の冷媒と圧力
制御弁(300)にて減圧される前の高圧側の冷媒との
間で熱交換を行う内部熱交換器(600)とを備え、圧
力制御弁(300)は、内部熱交換(600)を流出し
た冷媒の温度に基づいて内部熱交換器(600)の冷媒
出口側における冷媒圧力を制御することを特徴とする。According to the second aspect of the present invention, the compressor (100) for compressing the refrigerant and the radiator for cooling the refrigerant discharged from the compressor (100) and having the internal pressure equal to or higher than the critical pressure of the refrigerant (200), a pressure control valve (300) for reducing the pressure of the refrigerant flowing out of the radiator (200) and controlling the refrigerant pressure on the high pressure side, and a pressure control valve (30).
Evaporator (400) for evaporating the refrigerant decompressed in 0)
And an internal heat exchanger (600) for performing heat exchange between the low-pressure side refrigerant flowing out of the evaporator (400) and the high-pressure side refrigerant before being depressurized by the pressure control valve (300). The pressure control valve (300) controls a refrigerant pressure at a refrigerant outlet side of the internal heat exchanger (600) based on a temperature of the refrigerant flowing out of the internal heat exchange (600).
【0008】これにより、請求項1に記載の発明と同様
に、冷媒配管の経路を簡略化することができる。[0008] Thus, similarly to the first aspect of the invention, the route of the refrigerant pipe can be simplified.
【0009】なお、冷媒は、請求項3に記載の発明のご
とく、二酸化炭素を用いることが望ましい。Preferably, carbon dioxide is used as the refrigerant.
【0010】また、圧力制御弁(300)は、請求項4
に記載の発明のごとく、高圧側の圧力が冷媒の臨界圧力
以上となる超臨界領域では、冷媒温度と冷媒圧力とが所
定密度の等密度線に沿うような関係を有するように高圧
側の冷媒圧力を制御し、高圧側の圧力が冷媒の臨界圧力
未満となる未臨界域では、放熱器(200)出口側の冷
媒が所定の過冷却度を有するように高圧側の冷媒圧力を
制御することが望ましい。[0010] The pressure control valve (300) may further include:
In the supercritical region in which the pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant, the refrigerant on the high pressure side has a relation such that the refrigerant temperature and the refrigerant pressure are along a constant density line of a predetermined density. In the subcritical region where the pressure is controlled and the pressure on the high pressure side is lower than the critical pressure of the refrigerant, the refrigerant pressure on the high pressure side is controlled so that the refrigerant on the outlet side of the radiator (200) has a predetermined degree of supercooling. Is desirable.
【0011】これにより、因みに、上記各手段の括弧内
の符号は、後述する実施形態に記載の具体的手段との対
応関係を示す一例である。Accordingly, the reference numerals in parentheses of the above means are examples showing the correspondence with the concrete means described in the embodiments described later.
【0012】[0012]
【発明の実施の形態】(第1実施形態)本実施形態は、
二酸化炭素(CO2)を冷媒とする超臨界冷凍サイクル
に本発明を適用したものであり、図1は超臨界冷凍サイ
クルの模式図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
The present invention is applied to a supercritical refrigeration cycle using carbon dioxide (CO 2 ) as a refrigerant, and FIG. 1 is a schematic diagram of a supercritical refrigeration cycle.
【0013】図1中、100は冷媒を圧縮する圧縮機で
あり、200は圧縮機100にて圧縮された冷媒を冷却
する放熱器(ガスクーラ)である。300は放熱器20
0から流出する冷媒を減圧するとともに、高圧側の冷媒
圧力を制御する圧力制御弁であり、その詳細は、後述す
る。なお、高圧側の冷媒圧力とは、圧縮機100の吐出
側から圧力制御弁300の冷媒入口側に至る圧力制御弁
300にて減圧される前の冷媒圧力を言うものである。In FIG. 1, reference numeral 100 denotes a compressor for compressing the refrigerant, and reference numeral 200 denotes a radiator (gas cooler) for cooling the refrigerant compressed by the compressor 100. 300 is the radiator 20
The pressure control valve controls the pressure of the refrigerant on the high-pressure side while reducing the pressure of the refrigerant flowing out of the cylinder. The details will be described later. The high-pressure side refrigerant pressure refers to the refrigerant pressure before the pressure is reduced by the pressure control valve 300 from the discharge side of the compressor 100 to the refrigerant inlet side of the pressure control valve 300.
【0014】400は圧力制御弁300にて減圧された
(液相の)冷媒を蒸発させる蒸発器であり、500は蒸
発器400から流出する冷媒を気相冷媒と液相冷媒とに
分離して気相冷媒を圧縮機100の吸入側に流出させる
とともに、超臨界冷凍サイクル中の余剰冷媒を蓄えるア
キュームレータ(気液分離手段)である。Reference numeral 400 denotes an evaporator for evaporating the refrigerant (liquid phase) depressurized by the pressure control valve 300. Reference numeral 500 denotes a refrigerant which flows out of the evaporator 400 and is separated into a gaseous refrigerant and a liquid refrigerant. It is an accumulator (gas-liquid separation means) that allows the gas-phase refrigerant to flow out to the suction side of the compressor 100 and stores excess refrigerant in the supercritical refrigeration cycle.
【0015】600はアキュームレータ500から流出
する低圧側の冷媒と圧力制御弁300にて減圧される前
の高圧側の冷媒とを熱交換する内部熱交換器(以下、熱
交換器と略す。)であり、この熱交換器600により蒸
発器400入口側での冷媒のエンタルピを低下させて、
図2に示すように、超臨界冷凍サイクルの冷凍能力を向
上させている。Reference numeral 600 denotes an internal heat exchanger (hereinafter abbreviated as heat exchanger) for exchanging heat between the low-pressure refrigerant flowing out of the accumulator 500 and the high-pressure refrigerant before being depressurized by the pressure control valve 300. Yes, the heat exchanger 600 reduces the enthalpy of the refrigerant at the evaporator 400 inlet side,
As shown in FIG. 2, the refrigeration capacity of the supercritical refrigeration cycle is improved.
【0016】次に、圧力制御弁300の詳細構造につい
て図3を用いて述べる。Next, the detailed structure of the pressure control valve 300 will be described with reference to FIG.
【0017】310は熱交換器600から蒸発器400
に至る冷媒流路の一部を形成するとともに、制御弁本体
320を収納するケーシングであり、このケーシング3
10は、熱交換器600側に接続される流入口313が
形成された第1ケーシング311、及び蒸発器400側
に接続される流出口314が形成された第2ケーシング
312から形成されている。Reference numeral 310 denotes a heat exchanger 600 to an evaporator 400.
And a casing for accommodating the control valve body 320 while forming a part of a refrigerant flow path leading to the casing 3.
Reference numeral 10 denotes a first casing 311 having an inlet 313 connected to the heat exchanger 600 side and a second casing 312 having an outlet 314 connected to the evaporator 400 side.
【0018】321は、制御弁本体320のケーシング
の一部を兼ねるとともに、制御弁本体320を第2ケー
シング312にネジ止め固定すための取付部(隔壁部)
であり、この取付部(隔壁部)321は、ケーシング3
10内の空間(冷媒流路)を上流側空間315と下流側
空間316とに仕切っている。A mounting portion (partition portion) 321 serves also as a part of a casing of the control valve body 320 and is used for fixing the control valve body 320 to the second casing 312 with screws.
The mounting portion (partition portion) 321 is
The space (refrigerant flow path) in 10 is partitioned into an upstream space 315 and a downstream space 316.
【0019】そして、取付部(隔壁部)321には、両
空間315、316とを連通させる弁口322が形成さ
れており、この弁口322は、針状のニードル弁体(以
下、弁体と略す。)323により開閉される。The mounting portion (partition portion) 321 is formed with a valve port 322 for communicating the two spaces 315 and 316, and the valve port 322 is a needle-shaped needle valve (hereinafter referred to as a valve). 323).
【0020】また、上流側空間315には、密閉空間
(ガス封入室)324が形成されており、この密閉空間
324は、密閉空間324内外の圧力差に応じて変形変
位する、ステンレス材からなる薄膜状のダイヤフラム
(変位部材)325、及びダイヤフラム325の厚み方
向一端側に配設されたダイヤフラム上側支持部材(第1
部材)326から形成されている。A sealed space (gas sealing chamber) 324 is formed in the upstream space 315. The sealed space 324 is made of a stainless steel material which is deformed and displaced in accordance with a pressure difference between the inside and the outside of the sealed space 324. A diaphragm (displacement member) 325 in the form of a thin film, and a diaphragm upper supporting member (first member) disposed on one end side in the thickness direction of the diaphragm 325.
326).
【0021】一方、ダイヤフラム325の厚み方向他端
側には、ダイヤフラム上側支持部材(以下、上側支持部
材と略す。)326と共にダイヤフラム325の外縁部
を挟み込んでダイヤフラム325を保持するダイヤフラ
ム下側支持部材(保持部材)327が配設されており、
このダイヤフラム下側支持部材(以下、下側支持部材と
略す。)327のうち、ダイヤフラム325の外縁部に
形成された湾曲部(変形促進部)325aに対応する部
位には、図3に示すように、湾曲部325aの湾曲形状
に沿う形状に形成された凹部327aが形成されてい
る。On the other hand, on the other end side in the thickness direction of the diaphragm 325, a diaphragm lower supporting member for holding the diaphragm 325 by sandwiching the outer edge of the diaphragm 325 together with the diaphragm upper supporting member (hereinafter, abbreviated as upper supporting member) 326. (Holding member) 327 is provided,
As shown in FIG. 3, a portion of the diaphragm lower support member (hereinafter, abbreviated as a lower support member) 327 corresponding to a curved portion (deformation promoting portion) 325a formed on an outer edge portion of the diaphragm 325 is provided as shown in FIG. In addition, a concave portion 327a formed in a shape along the curved shape of the curved portion 325a is formed.
【0022】なお、湾曲部325aとは、ダイヤフラム
325の径外方側の一部をその厚み方向(本実施形態で
は下側支持部材327側)に向けて突出するように湾曲
させたもので、ダイヤフラム325が密閉空間324内
外の圧力差に略比例して変形変位するようにするための
ものである。The curved portion 325a is formed by curving a part of the radially outer side of the diaphragm 325 so as to protrude in the thickness direction thereof (in this embodiment, the lower support member 327 side). This is for the purpose of causing the diaphragm 325 to be deformed and displaced substantially in proportion to the pressure difference between the inside and outside of the closed space 324.
【0023】また、ダイヤフラム325と上側支持部材
326との間には、湾曲部325aの曲率が所定範囲外
となるまで(湾曲部325aが略平板状となるまで)ダ
イヤフラム325が変形変位することを抑制すべく、上
側支持部材326と別に設けられた金属製のプレート3
28が配設されている。Between the diaphragm 325 and the upper supporting member 326, the diaphragm 325 is deformed and displaced until the curvature of the curved portion 325a is out of a predetermined range (until the curved portion 325a becomes substantially flat). Metal plate 3 provided separately from upper support member 326 to suppress
28 are provided.
【0024】そして、プレート328は、湾曲部325
aの湾曲形状に沿うような形状にプレス成形されている
とともに、このプレート328のうち湾曲形状に沿うよ
うに下側支持部材327側に向けて突出するように湾曲
した部位(以下、この部位を変形抑制部328aと呼
ぶ。)は、ダイヤフラム325の剛性と同等又はそれよ
り高い剛性を有するように、材質及び板厚等が選定され
ている。The plate 328 has a curved portion 325.
The plate 328 is press-formed into a shape that conforms to the curved shape of FIG. a, and is a portion of the plate 328 that is curved to protrude toward the lower support member 327 along the curved shape (hereinafter, this portion is referred to as The material, plate thickness, and the like of the deformation suppressing portion 328a are selected so as to have a rigidity equal to or higher than the rigidity of the diaphragm 325.
【0025】また、ダイヤフラム325は、ダイヤフラ
ム325が中立状態から弁体304側(ダイヤフラム3
25の厚み方向他端側)に向けて変位したときに、弁体
323が弁口322を閉じる向きに変位し、一方、ダイ
ヤフラム325が厚み方向一端側(密閉空間324側)
に向けて変位したときに、弁体323が弁口322を開
く向きに変位するように、弁体323の長手方向一端側
にステンレス材料からなる補強部材332と共に溶接さ
れている。The diaphragm 325 is moved from the neutral state to the valve body 304 side (the diaphragm 3).
25, the valve body 323 is displaced in a direction to close the valve port 322, while the diaphragm 325 is moved in one direction in the thickness direction (closed space 324 side).
The valve body 323 is welded to one longitudinal end of the valve body 323 together with a reinforcing member 332 made of a stainless material so that the valve body 323 is displaced in a direction to open the valve port 322 when the valve body 323 is displaced.
【0026】ここで、ダイヤフラム325が中立状態で
あるとは、ダイヤフラム325が変形変位しておらず、
変形変位に伴う応力が略0の状態をいう。Here, that the diaphragm 325 is in the neutral state means that the diaphragm 325 is not deformed and displaced,
This refers to a state in which the stress accompanying the deformation displacement is substantially zero.
【0027】また、ダイヤフラム325の厚み方向他端
側には、圧力導入口329を介して熱交換器600出口
側の冷媒圧力(高圧側の冷媒圧力)が作用する。The refrigerant pressure at the outlet side of the heat exchanger 600 (the high-pressure refrigerant pressure) acts on the other end of the diaphragm 325 in the thickness direction via a pressure inlet 329.
【0028】一方、ダイヤフラム325の厚み方向一端
側には、図2に示すように、弁体323を介してコイル
バネ(弾性部材)330の弾性力が作用するとともに、
密閉空間324の内圧が作用しており、密閉空間324
の内圧は、上流側空間315内の冷媒温度に応じて変化
する。On the other hand, as shown in FIG. 2, an elastic force of a coil spring (elastic member) 330 acts on one end side in the thickness direction of the diaphragm 325 through a valve body 323, as shown in FIG.
The internal pressure of the closed space 324 is acting,
Changes according to the refrigerant temperature in the upstream space 315.
【0029】したがって、圧力制御弁300(弁体32
3)は、上流側空間315に位置する密閉空間324が
感温部として熱交換器600出口側の冷媒温度を感知し
て、その内圧による力とコイルバネ330の弾性力との
和(以下、この和を閉弁力と呼ぶ。)と、放熱器200
出口側の冷媒圧力による力(以下、この力を開弁力と呼
ぶ)との釣り合いにより可動する。Therefore, the pressure control valve 300 (the valve body 32
3) The closed space 324 located in the upstream space 315 senses the temperature of the refrigerant at the outlet side of the heat exchanger 600 as a temperature sensing part, and sums the force due to its internal pressure and the elastic force of the coil spring 330 (hereinafter, this is referred to as the The sum is called the valve closing force.)
It moves in balance with the force due to the refrigerant pressure on the outlet side (hereinafter, this force is referred to as the valve opening force).
【0030】ところで、本実施形態では、密閉空間32
4内には、冷媒がその温度が0℃での飽和液密度から臨
界点での飽和液密度に至る範囲の密度(本実施形態では
約700kg/m3)で封入されており、その密度は、
放熱器200出口側での冷媒温度と冷媒圧力との関係
が、特願平11−31776号公報と同様に図4の太い
実線ηmaxで示す関係となるように、熱交換器600で
の温度低下量ΔT1を考慮した値である。In the present embodiment, the closed space 32
In 4, the refrigerant is sealed at a density (about 700 kg / m 3 in this embodiment) ranging from a saturated liquid density at a temperature of 0 ° C. to a saturated liquid density at a critical point. ,
The temperature in the heat exchanger 600 is set such that the relationship between the refrigerant temperature and the refrigerant pressure at the outlet side of the radiator 200 becomes the relationship indicated by the thick solid line η max in FIG. 4 similarly to Japanese Patent Application No. 11-31776. This is a value in consideration of the decrease amount ΔT1.
【0031】具体的には、熱交換器600の冷媒入口側
(放熱器200の冷媒出口)での冷媒温度と熱交換器6
00の冷媒出口側での冷媒温度との差(温度低下量ΔT
1)は、図5に示すように、熱交換器600の冷媒出口
側での冷媒温度に略比例するので、密閉空間324内の
冷媒密度を特願平11−31776号公報(約600k
g/m3)に対して大きくすることにより、圧力制御弁
300の制御特性(冷媒温度に対する冷媒圧力)を図6
の実線に示すようにしている。因みに、図6の破線は、
特願平11−31776号公報における圧力制御弁の制
御特性を示すものである。Specifically, the temperature of the refrigerant at the refrigerant inlet side of the heat exchanger 600 (the refrigerant outlet of the radiator 200) and the heat exchanger 6
00 and the refrigerant temperature at the refrigerant outlet side (temperature decrease ΔT
1) is substantially proportional to the refrigerant temperature at the refrigerant outlet side of the heat exchanger 600, as shown in FIG. 5, so that the refrigerant density in the closed space 324 is determined by Japanese Patent Application No. 11-31776 (about 600 k).
g / m 3 ), the control characteristic of the pressure control valve 300 (refrigerant pressure with respect to the refrigerant temperature) is increased as shown in FIG.
As shown by the solid line. Incidentally, the broken line in FIG.
1 shows the control characteristics of a pressure control valve disclosed in Japanese Patent Application No. 11-31776.
【0032】また、コイルバネ330の初期設定荷重
(弁口322を閉じた状態での弾性力)は、冷媒が臨界
圧力以下の凝縮域において、所定の過冷却度(本実施形
態では約10℃)を有するように設定されている。因み
に、初期設定荷重は、密閉空間324内での圧力換算で
約0.5〜1[MPa]であり、初期設定加重は、調整
ナット331を回すことにより調節する。The initial load of the coil spring 330 (the elastic force with the valve port 322 closed) is a predetermined degree of supercooling (about 10 ° C. in the present embodiment) in a condensing region where the refrigerant is below the critical pressure. Is set to have. Incidentally, the initial set load is about 0.5 to 1 [MPa] in terms of pressure in the closed space 324, and the initial set load is adjusted by turning the adjustment nut 331.
【0033】このため、圧力制御弁300は、放熱器2
00出口側での冷媒温度と冷媒圧力との関係が、図4の
太い実線ηmaxに示すように、超臨界領域では、600
kg/m3の等密度線に沿うように、放熱器200出口
側の冷媒温度に基づいて放熱器200出口側の冷媒圧力
(図4のC点)を制御する。一方、臨界圧力以下では、
600kg/m3 の等密度線は、飽和液線SLに略沿っ
て変化する。このとき、コイルバネ330によって弁体
323に初期荷重が与えられているので、放熱器200
出口側の冷媒が約10℃の過冷却度(サブクール)を有
するように放熱器200出口側の冷媒圧力が制御され
る。For this reason, the pressure control valve 300 is
As shown by the thick solid line η max in FIG.
The refrigerant pressure (point C in FIG. 4) on the outlet side of the radiator 200 is controlled based on the refrigerant temperature on the outlet side of the radiator 200 so as to follow the isopycnic line of kg / m 3 . On the other hand, below the critical pressure,
The density line of 600 kg / m 3 changes substantially along the saturated liquid line SL. At this time, since the initial load is applied to the valve body 323 by the coil spring 330, the radiator 200
The refrigerant pressure on the outlet side of the radiator 200 is controlled such that the refrigerant on the outlet side has a degree of subcooling of about 10 ° C. (subcooling).
【0034】なお、本実施形態では、熱交換器600出
口側で弁開度を調節して高圧側の冷媒圧力を制御してい
るが、圧力制御弁300における圧力低下量に比べて熱
交換器600における圧力損失よる圧力低下量は十分に
小さいので、本実施形態では、実質的に熱交換器600
出口側の冷媒温度に基づいて放熱器200の冷媒圧力を
制御するものと言える。In this embodiment, the valve opening is adjusted at the outlet of the heat exchanger 600 to control the refrigerant pressure on the high pressure side. Since the amount of pressure drop due to the pressure loss at 600 is sufficiently small, in the present embodiment, the heat exchanger 600
It can be said that the refrigerant pressure of the radiator 200 is controlled based on the refrigerant temperature on the outlet side.
【0035】因みに、図3中、324aは密閉空間32
4(感温部)に冷媒を封入する封入管であり、この封入
管324aは、上流側空間315内の冷媒温度に対して
密閉空間324内の冷媒温度を時間差無く追従させるべ
く、銅などの熱伝導率の高い金属にて形成されている。Incidentally, in FIG. 3, 324a is a closed space 32.
4 (temperature sensing part) is a sealing tube for sealing the refrigerant. The sealing tube 324a is made of copper or the like so that the refrigerant temperature in the closed space 324 follows the refrigerant temperature in the upstream space 315 without a time difference. It is formed of a metal having high thermal conductivity.
【0036】次に、本実施形態の特徴を述べる。Next, the features of this embodiment will be described.
【0037】本実施形態によれば、熱交換器600から
流出する冷媒の温度を検出して高圧側の冷媒圧力を制御
しているので、圧力制御弁300にて冷媒温度を感知さ
せるために、一旦、冷媒を圧力制御弁300に流入させ
た後に熱交換器600に流入させる必要がなく、冷媒配
管の経路を簡略化することができる。According to the present embodiment, the temperature of the refrigerant flowing out of the heat exchanger 600 is detected to control the refrigerant pressure on the high pressure side, so that the pressure control valve 300 detects the refrigerant temperature. There is no need to once flow the refrigerant into the heat exchanger 600 after flowing into the pressure control valve 300, so that the path of the refrigerant pipe can be simplified.
【0038】(第2実施形態)第1実施形態では、密閉
空間324に封入する冷媒の密度のみを調整することに
より熱交換器600での温度低下分を補正したが、本実
施形態は、密閉空間324に封入する冷媒の密度に加え
て、コイルバネ330の初期設定荷重も大きくすること
により、圧力制御弁300の制御特性を図7の実線で示
すようにしたものである。因みに、破線は上記出願にお
ける圧力制御弁300の制御特性を示すものである。(Second Embodiment) In the first embodiment, the temperature decrease in the heat exchanger 600 is corrected by adjusting only the density of the refrigerant sealed in the closed space 324. The control characteristic of the pressure control valve 300 is shown by a solid line in FIG. 7 by increasing the initial load of the coil spring 330 in addition to the density of the refrigerant sealed in the space 324. Incidentally, the broken line indicates the control characteristics of the pressure control valve 300 in the above-mentioned application.
【0039】(第3実施形態)第1、2実施形態に係る
圧力制御弁300は、密閉空間324に封入する冷媒の
密度によって冷媒温度と冷媒圧力とが所定の関係を示す
と言う点を利用した機械式のものであったが、本実施形
態は、図8に示すように、熱交換器600出口側の冷媒
温度を検出する温度センサ(冷媒温度検出手段)34
0、及び放熱器200出口側の冷媒圧力を検出する圧力
センサ(冷媒圧力検出手段)350の検出値に基づいて
電気的に作動する電気式の圧力制御弁300を採用した
ものである。なお、350は電気式の圧力制御弁300
を制御する電子制御装置(ECU)である。(Third Embodiment) The pressure control valve 300 according to the first and second embodiments utilizes a point that the refrigerant temperature and the refrigerant pressure show a predetermined relationship depending on the density of the refrigerant sealed in the closed space 324. In the present embodiment, as shown in FIG. 8, a temperature sensor (refrigerant temperature detecting means) 34 for detecting a refrigerant temperature at the outlet side of the heat exchanger 600 is used.
0, and an electric pressure control valve 300 that is electrically operated based on a detection value of a pressure sensor (refrigerant pressure detecting means) 350 that detects the refrigerant pressure at the outlet side of the radiator 200. 350 is an electric pressure control valve 300
Is an electronic control unit (ECU) for controlling the ECU.
【0040】(その他の実施形態)上述の実施形態で
は、熱交換器600の出口側で弁開度を調節したが、前
述のごとく、放熱器200から圧力制御弁300までに
至る間においては、冷媒の圧力は略一定であると見なす
ことができるので、熱交換器600の入口側圧力で弁開
度を調節してもよい。(Other Embodiments) In the above-described embodiment, the valve opening is adjusted at the outlet side of the heat exchanger 600. However, as described above, between the radiator 200 and the pressure control valve 300, Since the pressure of the refrigerant can be considered to be substantially constant, the valve opening may be adjusted by the pressure on the inlet side of the heat exchanger 600.
【0041】また、上述の実施形態では、冷媒としてC
O2を用いたが本発明に係る超臨界冷凍サイクルの冷媒
はこれに限定されるものではなく、例えば、エチレン、
エタン、酸化窒素等でもよい。In the above embodiment, the refrigerant is C
Although O 2 was used, the refrigerant of the supercritical refrigeration cycle according to the present invention is not limited to this. For example, ethylene,
Ethane, nitric oxide or the like may be used.
【図1】本発明の第1実施形態に係る超臨界冷凍サイク
ルの模式図である。FIG. 1 is a schematic diagram of a supercritical refrigeration cycle according to a first embodiment of the present invention.
【図2】二酸化炭素のp−h線図である。FIG. 2 is a ph diagram of carbon dioxide.
【図3】本発明の第1実施形態に係る超臨界冷凍サイク
ルにおける圧力制御弁の模式図である。FIG. 3 is a schematic diagram of a pressure control valve in the supercritical refrigeration cycle according to the first embodiment of the present invention.
【図4】二酸化炭素のp−h線図である。FIG. 4 is a ph diagram of carbon dioxide.
【図5】温度低下量ΔT1と内部熱交換器出口側での冷
媒温度との関係を示すグラフである。FIG. 5 is a graph showing the relationship between the temperature decrease ΔT1 and the refrigerant temperature at the outlet of the internal heat exchanger.
【図6】本発明の第1実施形態に係る超臨界冷凍サイク
ルにおける圧力制御弁の制御特性を示すグラフである。FIG. 6 is a graph showing control characteristics of a pressure control valve in the supercritical refrigeration cycle according to the first embodiment of the present invention.
【図7】本発明の第2実施形態に係る超臨界冷凍サイク
ルにおける圧力制御弁の制御特性を示すグラフである。FIG. 7 is a graph showing control characteristics of a pressure control valve in a supercritical refrigeration cycle according to a second embodiment of the present invention.
【図8】本発明の第1実施形態に係る超臨界冷凍サイク
ルの模式図である。FIG. 8 is a schematic diagram of a supercritical refrigeration cycle according to the first embodiment of the present invention.
100…圧縮機、200…放熱器、300…圧力制御
弁、400…蒸発器、500…アキュムレータ、600
…内部熱交換器。100: compressor, 200: radiator, 300: pressure control valve, 400: evaporator, 500: accumulator, 600
… Internal heat exchanger.
Claims (4)
もに、内部の圧力が冷媒の臨界圧力以上となる放熱器
(200)と、 前記放熱器(200)から流出する冷媒を減圧するとと
もに、高圧側の冷媒圧力を制御する圧力制御弁(30
0)と、 前記圧力制御弁(300)にて減圧された冷媒を蒸発さ
せる蒸発器(400)と、 前記蒸発器(400)から流出する低圧側の冷媒と前記
圧力制御弁(300)にて減圧される前の高圧側の冷媒
との間で熱交換を行う内部熱交換器(600)とを備
え、 前記圧力制御弁(300)は、前記内部熱交換器(60
0)を流出した冷媒の温度に基づいて高圧側の冷媒圧力
を制御することを特徴とする超臨界冷凍サイクル。1. A compressor (100) for compressing a refrigerant, a radiator (200) for cooling a refrigerant discharged from the compressor (100) and having an internal pressure equal to or higher than a critical pressure of the refrigerant, A pressure control valve (30) for reducing the pressure of the refrigerant flowing out of the radiator (200) and controlling the pressure of the refrigerant on the high pressure side.
0), an evaporator (400) for evaporating the refrigerant depressurized by the pressure control valve (300), a low-pressure side refrigerant flowing out of the evaporator (400) and the pressure control valve (300). An internal heat exchanger (600) that exchanges heat with the refrigerant on the high pressure side before the pressure is reduced, and the pressure control valve (300) is provided with the internal heat exchanger (60).
A supercritical refrigeration cycle characterized in that the refrigerant pressure on the high pressure side is controlled based on the temperature of the refrigerant flowing out from 0).
もに、内部の圧力が冷媒の臨界圧力以上となる放熱器
(200)と、 前記放熱器(200)から流出する冷媒を減圧するとと
もに、高圧側の冷媒圧力を制御する圧力制御弁(30
0)と、 前記圧力制御弁(300)にて減圧された冷媒を蒸発さ
せる蒸発器(400)と、 前記蒸発器(400)から流出する低圧側の冷媒と前記
圧力制御弁(300)にて減圧される前の高圧側の冷媒
との間で熱交換を行う内部熱交換器(600)とを備
え、 前記圧力制御弁(300)は、前記内部熱交換(60
0)を流出した冷媒の温度に基づいて前記内部熱交換器
(600)の冷媒出口側における冷媒圧力を制御するこ
とを特徴とする超臨界冷凍サイクル。2. A compressor (100) for compressing a refrigerant, a radiator (200) for cooling a refrigerant discharged from the compressor (100) and having an internal pressure equal to or higher than a critical pressure of the refrigerant, A pressure control valve (30) for reducing the pressure of the refrigerant flowing out of the radiator (200) and controlling the pressure of the refrigerant on the high pressure side.
0), an evaporator (400) for evaporating the refrigerant depressurized by the pressure control valve (300), a low-pressure side refrigerant flowing out of the evaporator (400) and the pressure control valve (300). An internal heat exchanger (600) that performs heat exchange with the high-pressure side refrigerant before the pressure is reduced, and the pressure control valve (300) is configured to perform the internal heat exchange (60).
A supercritical refrigeration cycle, wherein the refrigerant pressure at the refrigerant outlet side of the internal heat exchanger (600) is controlled based on the temperature of the refrigerant flowing out of 0).
特徴とする請求項1又は2に記載の超臨界冷凍サイク
ル。3. The supercritical refrigeration cycle according to claim 1, wherein carbon dioxide is used as the refrigerant.
圧力が冷媒の臨界圧力以上となる超臨界領域では、冷媒
温度と冷媒圧力とが所定密度の等密度線に沿うような関
係を有するように高圧側の冷媒圧力を制御し、高圧側の
圧力が冷媒の臨界圧力未満となる未臨界域では、放熱器
(200)出口側の冷媒が所定の過冷却度を有するよう
に高圧側の冷媒圧力を制御することを特徴とする請求項
1ないし3のいずれか1つに記載の超臨界冷凍サイク
ル。4. The pressure control valve (300) has a relation such that the refrigerant temperature and the refrigerant pressure are along a constant density line of a predetermined density in a supercritical region where the pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. The refrigerant pressure on the high pressure side is controlled so that the refrigerant on the high pressure side has a predetermined degree of supercooling in a subcritical region where the pressure on the high pressure side is lower than the critical pressure of the refrigerant. The supercritical refrigeration cycle according to any one of claims 1 to 3, wherein the refrigerant pressure is controlled.
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JP28720499A JP2001108308A (en) | 1999-10-07 | 1999-10-07 | Supercritical refrigerating cycle |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1932696A2 (en) | 2006-12-15 | 2008-06-18 | TGK Co., Ltd. | Automotive air conditioner |
EP1961598A1 (en) | 2007-02-23 | 2008-08-27 | TGK Co., Ltd. | Internal heat exchanger for automotive air conditioner |
US8205470B2 (en) | 2006-09-29 | 2012-06-26 | Daikin Industries, Ltd. | Indoor unit for air conditioner |
JP2013181666A (en) * | 2012-02-29 | 2013-09-12 | Fujitsu General Ltd | Air conditioning system |
-
1999
- 1999-10-07 JP JP28720499A patent/JP2001108308A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8205470B2 (en) | 2006-09-29 | 2012-06-26 | Daikin Industries, Ltd. | Indoor unit for air conditioner |
EP1932696A2 (en) | 2006-12-15 | 2008-06-18 | TGK Co., Ltd. | Automotive air conditioner |
EP1932696A3 (en) * | 2006-12-15 | 2008-07-23 | TGK Co., Ltd. | Automotive air conditioner |
EP1961598A1 (en) | 2007-02-23 | 2008-08-27 | TGK Co., Ltd. | Internal heat exchanger for automotive air conditioner |
JP2013181666A (en) * | 2012-02-29 | 2013-09-12 | Fujitsu General Ltd | Air conditioning system |
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Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20080318 |