JP2018173191A - Air conditioner - Google Patents

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JP2018173191A
JP2018173191A JP2017069971A JP2017069971A JP2018173191A JP 2018173191 A JP2018173191 A JP 2018173191A JP 2017069971 A JP2017069971 A JP 2017069971A JP 2017069971 A JP2017069971 A JP 2017069971A JP 2018173191 A JP2018173191 A JP 2018173191A
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heat medium
heat exchanger
refrigerant
heat
indoor
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伊藤 俊太郎
Shuntaro Ito
俊太郎 伊藤
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Fujitsu General Ltd
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Fujitsu General Ltd
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Abstract

PROBLEM TO BE SOLVED: To avoid surplus capacity in low load cooling operation, in an air conditioner where a relay unit is arranged between an outdoor machine and an indoor machine.SOLUTION: An air conditioner 1A is configured to, when performing only cooling operation of some indoor machines out of a plurality of indoor machines, make a first intermediate heat exchanger 211 function as an evaporator, make a second intermediate heat exchanger 212 function as a condenser, and cause a heat exchanger 701 between heat media to perform heat exchange between a heat medium circulating in a bypass circuit 25 and a heat medium circulating in a first heat medium circuit, so that a temperature of the heat medium circulating in the first heat medium circuit can be prevented from excessively decreasing to avoid system stop (stop of a compressor).SELECTED DRAWING: Figure 2

Description

本発明は、室外機と室内機の間に中継ユニットを配置した空気調和装置に関する。   The present invention relates to an air conditioner in which a relay unit is disposed between an outdoor unit and an indoor unit.

特許文献1では、少なくとも1台の室外機と複数の室内機を備えた多室型空気調和装置において、室外機と室内機の間に中継ユニットを配置した空気調和装置が示されている。この空気調和装置では、室外機と中継ユニットが冷媒を循環させる冷媒配管で接続されて、冷媒回路を構成している。一方、中継ユニットと複数の室内機が熱媒体(水や不凍液など)を循環させる熱媒体配管で接続されて、熱媒体回路を構成している。中継ユニット内に中間熱交換器が配置され、この中間熱交換器が冷媒回路と熱媒体回路の両方に接続され、冷媒と熱媒体を熱交換させている。   Patent Document 1 discloses an air conditioner in which a relay unit is arranged between an outdoor unit and an indoor unit in a multi-room type air conditioner including at least one outdoor unit and a plurality of indoor units. In this air conditioner, an outdoor unit and a relay unit are connected by a refrigerant pipe that circulates a refrigerant to constitute a refrigerant circuit. On the other hand, the relay unit and a plurality of indoor units are connected by a heat medium pipe that circulates a heat medium (water, antifreeze liquid, etc.) to constitute a heat medium circuit. An intermediate heat exchanger is disposed in the relay unit, and this intermediate heat exchanger is connected to both the refrigerant circuit and the heat medium circuit to exchange heat between the refrigerant and the heat medium.

再公表特許 WO2010/049999号公報Republished patent WO2010 / 049999

特許文献1に開示されている空気調和装置では、中継ユニット内に中間熱交換器が二つ設けられている。二つのうち一方の中間熱交換器は室内機が冷房運転するために熱媒体を冷却する蒸発器専用となっており、他方の中間熱交換器は室内機が暖房運転するために熱媒体を加熱する凝縮器専用となっている。   In the air conditioner disclosed in Patent Document 1, two intermediate heat exchangers are provided in the relay unit. One of the two intermediate heat exchangers is dedicated to the evaporator that cools the heat medium in order to cool the indoor unit, and the other intermediate heat exchanger heats the heat medium in order to heat the indoor unit. It is dedicated to the condenser.

このような空気調和装置では、圧縮機の回転数、中継ユニット内の膨張弁の開度、さらには中継ユニット内のポンプの回転数などの調整による能力調整が行われる。しかし、例えば複数の室内機のうち一台のみ冷房運転を行い、かつ室内の温度が低いような低負荷冷房運転の場合、冷房能力の調整が追いつかず、能力過多となり熱媒体の温度が低下しすぎて、熱交換器や熱媒体の氷結保護機能によってシステム停止(圧縮機停止)が頻発するという問題があった。   In such an air conditioner, capacity adjustment is performed by adjusting the rotational speed of the compressor, the opening degree of the expansion valve in the relay unit, and further the rotational speed of the pump in the relay unit. However, for example, in the case of low-load cooling operation where only one of the plurality of indoor units performs cooling operation and the indoor temperature is low, the adjustment of the cooling capacity cannot catch up, the capacity is excessive, and the temperature of the heat medium decreases. Therefore, there has been a problem that system stoppage (compressor stoppage) frequently occurs due to the ice protection function of the heat exchanger and the heat medium.

以上のような事情に鑑み、本発明の目的は、室外機と室内機の間に中継ユニットを配置した空気調和装置において、低負荷冷房運転時のシステム停止を回避することのできる空気調和装置を提供することにある。   In view of the circumstances as described above, an object of the present invention is to provide an air conditioner that can avoid a system stop during low-load cooling operation in an air conditioner in which a relay unit is disposed between an outdoor unit and an indoor unit. It is to provide.

上記目的を達成するため、本発明の一形態に係る空気調和装置は、圧縮機と室外熱交換器とを備えた室外機と、前記室外機から引き出されたガス管と液管と、冷媒側流路と熱媒体側流路を有する第1中間熱交換器と、冷媒側流路と熱媒体側流路を有する第2中間熱交換器と、第1ポンプと、第2ポンプと、室内熱交換器を有する複数の室内機と、前記複数の室内熱交換器のそれぞれの両端に接続され、前記第1ポンプと前記第1中間熱交換器の熱媒体側流路と前記室内熱交換器が接続される第1熱媒体回路と、前記第2ポンプと前記第2中間熱交換器の熱媒体側流路と前記室内熱交換器が接続される第2熱媒体回路のいずれか一方を確立するための熱媒体回路切換部と、前記室内熱交換器を流通させることなく前記第2ポンプおよび前記第2中間熱交換器に熱媒体を循環させるバイパス回路と、前記バイパス回路に設けられ、前記バイパス回路を循環する熱媒体と前記第1熱媒体回路を循環する熱媒体との間で熱交換させる熱媒体間熱交換器とを備え、前記第1中間熱交換器の冷媒側流路の一端と、前記第2中間熱交換器の冷媒側流路の一端がそれぞれ前記ガス管に接続され、前記第1中間熱交換器の冷媒側流路の他端と、前記第2中間熱交換器の冷媒側流路の他端がそれぞれ前記液管に接続され、前記複数の室内機において一部の前記室内機の冷房運転のみを行う時、前記第1中間熱交換器を蒸発器として機能させるとともに、前記第2中間熱交換器を凝縮器として機能させるようにしたことを特徴とする。   In order to achieve the above object, an air conditioner according to an aspect of the present invention includes an outdoor unit including a compressor and an outdoor heat exchanger, a gas pipe and a liquid pipe drawn from the outdoor unit, and a refrigerant side. A first intermediate heat exchanger having a flow path and a heat medium side flow path; a second intermediate heat exchanger having a refrigerant side flow path and a heat medium side flow path; a first pump; a second pump; A plurality of indoor units having an exchanger, and connected to both ends of each of the plurality of indoor heat exchangers, the heat pump side of the first pump and the first intermediate heat exchanger, and the indoor heat exchanger One of the first heat medium circuit to be connected, the second pump, the heat medium side flow path of the second intermediate heat exchanger, and the second heat medium circuit to which the indoor heat exchanger is connected is established. And the second pump and the second without circulating the indoor heat exchanger. A bypass circuit that circulates the heat medium in the intermediate heat exchanger, and a heat medium that is provided in the bypass circuit and exchanges heat between the heat medium that circulates in the bypass circuit and the heat medium that circulates in the first heat medium circuit An intermediate heat exchanger, one end of the refrigerant side flow path of the first intermediate heat exchanger and one end of the refrigerant side flow path of the second intermediate heat exchanger are connected to the gas pipe, respectively, The other end of the refrigerant side flow path of the intermediate heat exchanger and the other end of the refrigerant side flow path of the second intermediate heat exchanger are each connected to the liquid pipe, and some of the indoor units in the plurality of indoor units When only the cooling operation is performed, the first intermediate heat exchanger functions as an evaporator, and the second intermediate heat exchanger functions as a condenser.

本発明の空気調和装置では、複数の室内機において一部の室内機の冷房運転のみを行う時、第1中間熱交換器を蒸発器として機能させ、第2中間熱交換器を凝縮器として機能させ、熱媒体間熱交換器によって、第2中間熱交換器を通過しバイパス回路を循環する熱媒体と、第1中間熱交換器を通過し第1熱媒体回路を循環する熱媒体との間で熱交換させることによって、第1熱媒体回路を循環する熱媒体の温度が低下しすぎることを防止することができ、システム停止(圧縮機停止)を回避することができる。   In the air conditioner of the present invention, when only some of the indoor units are cooled in the plurality of indoor units, the first intermediate heat exchanger functions as an evaporator, and the second intermediate heat exchanger functions as a condenser. Between the heat medium that passes through the second intermediate heat exchanger and circulates in the bypass circuit and the heat medium that passes through the first intermediate heat exchanger and circulates in the first heat medium circuit. By exchanging heat at, it is possible to prevent the temperature of the heat medium circulating in the first heat medium circuit from being lowered excessively, and to avoid a system stop (compressor stop).

本発明によれば、室外機と室内機の間に中継ユニットを配置した空気調和装置において、低負荷冷房運転時の能力過多を解消でき、システム停止を回避することができる。   ADVANTAGE OF THE INVENTION According to this invention, in the air conditioning apparatus which has arrange | positioned the relay unit between the outdoor unit and the indoor unit, excessive capacity at the time of low load cooling operation can be eliminated, and system stop can be avoided.

室外機と室内機の間に中継ユニットを配置した典型的な空気調和装置1の構成を全ての室内機が冷房運転を行っている場合の冷媒および熱媒体の流れとともに示した回路図である。It is the circuit diagram which showed the structure of the typical air conditioning apparatus 1 which has arrange | positioned the relay unit between the outdoor unit and the indoor unit with the flow of the refrigerant | coolant and the heat medium when all the indoor units are performing the cooling operation. 本発明に係る一実施形態の空気調和装置1Aの構成を示す回路図である。It is a circuit diagram showing composition of air harmony device 1A of one embodiment concerning the present invention.

以下、本発明に係る実施形態を説明する。
<典型的な空気調和装置の構成>
図1は、室外機と室内機の間に中継ユニットを配置した典型的な空気調和装置1の構成を全ての室内機が冷房運転を行っている場合の冷媒および熱媒体の流れとともに示した回路図である。
Embodiments according to the present invention will be described below.
<Configuration of typical air conditioner>
FIG. 1 is a circuit diagram showing a configuration of a typical air conditioner 1 in which a relay unit is arranged between an outdoor unit and an indoor unit, together with refrigerant and heat medium flows when all the indoor units are in cooling operation. FIG.

図1に示すように、この空気調和装置1は、1台の室外機100と、1台の中継ユニット200と、3台の室内機300a〜300cと、高圧ガス管410と、低圧ガス管420と、液管430とを備えている。室外機100と中継ユニット200が、高圧ガス管410と低圧ガス管420と液管430とで相互に接続されることによって、冷媒回路20が構成される。また、中継ユニット200と室内機300a〜300cが、熱媒体配管501〜506で相互に接続されることによって、熱媒体回路30が構成される。熱媒体回路30は、第1ポンプ231および第1中間熱交換器211が接続される第1熱媒体回路と、第2ポンプ232および第2中間熱交換器212が接続される第2熱媒体回路からなる。   As shown in FIG. 1, the air conditioner 1 includes one outdoor unit 100, one relay unit 200, three indoor units 300 a to 300 c, a high pressure gas pipe 410, and a low pressure gas pipe 420. And a liquid pipe 430. The outdoor unit 100 and the relay unit 200 are connected to each other by a high pressure gas pipe 410, a low pressure gas pipe 420, and a liquid pipe 430, whereby the refrigerant circuit 20 is configured. Further, the relay unit 200 and the indoor units 300a to 300c are connected to each other through the heat medium pipes 501 to 506, whereby the heat medium circuit 30 is configured. The heat medium circuit 30 includes a first heat medium circuit to which the first pump 231 and the first intermediate heat exchanger 211 are connected, and a second heat medium circuit to which the second pump 232 and the second intermediate heat exchanger 212 are connected. Consists of.

室外機100について以下に説明する。室外機100は、主として、圧縮機110と、四方弁120と、室外熱交換器130と、室外ファン140と、室外膨張弁150とを備えている。   The outdoor unit 100 will be described below. The outdoor unit 100 mainly includes a compressor 110, a four-way valve 120, an outdoor heat exchanger 130, an outdoor fan 140, and an outdoor expansion valve 150.

圧縮機110は、インバータにより回転数が制御される図示しないモータによって駆動されることで運転容量を可変できる能力可変型圧縮機である。図1に示すように、圧縮機110の吐出側は閉鎖弁101に接続されており、圧縮機110と閉鎖弁101との間から分岐した配管が四方弁120に接続されている。また、圧縮機110の吸入側は閉鎖弁103に接続されている。   The compressor 110 is a variable capacity compressor that can vary the operation capacity by being driven by a motor (not shown) whose rotation speed is controlled by an inverter. As shown in FIG. 1, the discharge side of the compressor 110 is connected to the closing valve 101, and a pipe branched from between the compressor 110 and the closing valve 101 is connected to the four-way valve 120. The suction side of the compressor 110 is connected to the closing valve 103.

四方弁120は、冷媒の流れる方向を切り換えるための弁であり、図1に示すように、a〜dの4つのポートを備えている。この四方弁120では、ポートaが上述したように圧縮機110の吐出側と、ポートbが室外熱交換器130の一方の冷媒出入口と、ポートcが圧縮機110の吸入側と閉鎖弁103とを接続する配管と、ポートdがキャピラリチューブ171を介してポートcが接続される配管にそれぞれ接続されている。また、室外熱交換器130の他方の冷媒出入口は室外膨張弁150を介して閉鎖弁102に接続されている。   The four-way valve 120 is a valve for switching the direction in which the refrigerant flows, and includes four ports a to d as shown in FIG. In this four-way valve 120, the port a is the discharge side of the compressor 110 as described above, the port b is one refrigerant inlet / outlet port of the outdoor heat exchanger 130, the port c is the suction side of the compressor 110, and the closing valve 103. And the port d are connected to the pipe to which the port c is connected via the capillary tube 171. The other refrigerant inlet / outlet of the outdoor heat exchanger 130 is connected to the closing valve 102 via the outdoor expansion valve 150.

空気調和装置1において、室内機300a〜300cが全て冷房運転を行う場合は、四方弁120のポートaとポートbとを連通すると同時にポートcとポートdとを連通するよう切り換えて、室外熱交換器130を凝縮器として機能させる。   In the air conditioner 1, when all of the indoor units 300a to 300c perform the cooling operation, the outdoor heat exchange is performed by switching the port a and the port b of the four-way valve 120 to communicate with each other at the same time. The vessel 130 functions as a condenser.

また、室内機300a〜300cが全て暖房運転を行う場合は、四方弁120のポートaとポートdとを連通すると同時にポートbとポートcとを連通するよう切り換えて、室外熱交換器130を蒸発器として機能させる。   Further, when all the indoor units 300a to 300c perform the heating operation, the outdoor heat exchanger 130 is evaporated by switching the port a and the port d of the four-way valve 120 to communicate with each other at the same time. Function as a container.

尚、四方弁120の連通しているポート間は実線で示し、連通していないポート間は破線で示している。   Ports that communicate with the four-way valve 120 are indicated by solid lines, and ports that do not communicate are indicated by broken lines.

室外膨張弁150は、室外熱交換器130と閉鎖弁102との間に設けられる。室外膨張弁150は、例えば冷房運転時に室外熱交換器130が凝縮器として機能する場合は、その開度を全開状態とする。また、暖房運転時に室外熱交換器130が蒸発器として機能する場合は、その開度を絞ることで通過する冷媒を減圧する。   The outdoor expansion valve 150 is provided between the outdoor heat exchanger 130 and the closing valve 102. For example, when the outdoor heat exchanger 130 functions as a condenser during cooling operation, the outdoor expansion valve 150 is fully opened. Moreover, when the outdoor heat exchanger 130 functions as an evaporator during heating operation, the refrigerant passing therethrough is depressurized by reducing its opening.

次に、中継ユニット200について説明する。
中継ユニット200は、主として、第1中間熱交換器211と、第2中間熱交換器212と、第1ポンプ231と、第2ポンプ232と、第1中継膨張弁271と、第2中継膨張弁272と、第1冷媒回路切換部221と、第2冷媒回路切換部222と、第1熱媒体回路切換部223a〜223cと、第2熱媒体回路切換部224a〜224cを備えている。また、室外機100より引き出された液管430は接続部202に接続され、高圧ガス管410は接続部201に接続され、低圧ガス管420は接続部203に接続されている。さらに、各室内機300a、300b、300cに熱媒体を循環させる熱媒体配管501〜506は接続部291〜296に接続される。接続部201〜203、291〜296は配管と配管を繋ぐためのものであり、例えばフレアナットより構成されている。
Next, the relay unit 200 will be described.
The relay unit 200 mainly includes a first intermediate heat exchanger 211, a second intermediate heat exchanger 212, a first pump 231, a second pump 232, a first relay expansion valve 271, and a second relay expansion valve. 272, a first refrigerant circuit switching unit 221, a second refrigerant circuit switching unit 222, first heat medium circuit switching units 223a to 223c, and second heat medium circuit switching units 224a to 224c. The liquid pipe 430 drawn from the outdoor unit 100 is connected to the connection unit 202, the high pressure gas pipe 410 is connected to the connection unit 201, and the low pressure gas pipe 420 is connected to the connection unit 203. Furthermore, the heat medium pipes 501 to 506 for circulating the heat medium to the indoor units 300a, 300b, and 300c are connected to the connection portions 291 to 296, respectively. The connection parts 201 to 203 and 291 to 296 are for connecting the pipes to each other, and are composed of, for example, a flare nut.

第1中間熱交換器211と第2中間熱交換器212は、内部に冷媒が流通する冷媒側流路と熱媒体が流通する熱媒体側流路を備え、冷媒と熱媒体の間で熱交換を行なわせるもので、各々の流路には出入口が2つずつ設けられている。室内機300a〜300cが全て冷房運転を行う場合は第1中間熱交換器211と第2中間熱交換器212は共に蒸発器として機能し、室内機300a〜300cが全て暖房運転を行う場合は第1中間熱交換器211と第2中間熱交換器212は共に凝縮器として機能し、室内機300a〜300cで冷房運転と暖房運転が混在している場合は第1中間熱交換器211が蒸発器として第2中間熱交換器212は凝縮器として機能する。本実施形態の第1中間熱交換器211と第2中間熱交換器212はそれぞれ一つの熱交換ユニットより構成されているが、本発明はこれに限定したものではなく、例えば小型の熱交換ユニットを並列に配置して構成された熱交換器などを用いてよい。   The first intermediate heat exchanger 211 and the second intermediate heat exchanger 212 include a refrigerant side flow path through which the refrigerant flows and a heat medium side flow path through which the heat medium flows, and exchange heat between the refrigerant and the heat medium. In each of the flow paths, two entrances are provided. When all the indoor units 300a to 300c perform the cooling operation, both the first intermediate heat exchanger 211 and the second intermediate heat exchanger 212 function as an evaporator, and when all the indoor units 300a to 300c perform the heating operation. Both the first intermediate heat exchanger 211 and the second intermediate heat exchanger 212 function as a condenser, and when the cooling operation and the heating operation are mixed in the indoor units 300a to 300c, the first intermediate heat exchanger 211 is an evaporator. The second intermediate heat exchanger 212 functions as a condenser. The first intermediate heat exchanger 211 and the second intermediate heat exchanger 212 of the present embodiment are each composed of one heat exchange unit. However, the present invention is not limited to this, for example, a small heat exchange unit. You may use the heat exchanger etc. which were arrange | positioned in parallel and comprised.

冷媒回路20においては、第1中間熱交換器211の冷媒側流路の一端の冷媒出入口eは、接続部202に接続されており、第1中間熱交換器211の冷媒側流路の一端の冷媒出入口eと接続部202の間に第1中継膨張弁271が設けられる。第1中間熱交換器211の冷媒側流路の他端の冷媒出入口fは、第1冷媒回路切換部221に接続されている。第1冷媒回路切換部221は各々の一端が一点で接続された三本の冷媒配管221a、221b、221cと三本の冷媒配管のうちの二本221b、221cのそれぞれに設けられた電磁弁281b、281cで形成される。そのうち一本の配管221aの他端は上述のように第1中間熱交換器211の冷媒側流路の他端の冷媒出入口fに、もう一本の配管221bの他端は接続部203に、残りの一本の配管221cの他端は接続部201に接続されている。配管221bには電磁弁281bが設けられ、配管221cには電磁弁281cが設けられる。電磁弁281bと電磁弁281cの一方を開けて、他方を閉じることで冷媒の流れを切り換えている。   In the refrigerant circuit 20, the refrigerant inlet / outlet e at one end of the refrigerant side flow path of the first intermediate heat exchanger 211 is connected to the connection portion 202, and the one end of the refrigerant side flow path of the first intermediate heat exchanger 211 is connected. A first relay expansion valve 271 is provided between the refrigerant inlet / outlet e and the connection portion 202. The refrigerant inlet / outlet f at the other end of the refrigerant side flow path of the first intermediate heat exchanger 211 is connected to the first refrigerant circuit switching unit 221. The first refrigerant circuit switching unit 221 has three refrigerant pipes 221a, 221b, and 221c each having one end connected at one point, and two solenoid valves 281b and 221c of the three refrigerant pipes 221b and 221c. , 281c. Of these, the other end of one pipe 221a is connected to the refrigerant inlet / outlet f at the other end of the refrigerant side flow path of the first intermediate heat exchanger 211, and the other end of the other pipe 221b is connected to the connecting portion 203. The other end of the remaining one pipe 221c is connected to the connecting portion 201. The piping 221b is provided with an electromagnetic valve 281b, and the piping 221c is provided with an electromagnetic valve 281c. The refrigerant flow is switched by opening one of the electromagnetic valves 281b and 281c and closing the other.

第2中間熱交換器212の冷媒側流路の一端の冷媒出入口αも、接続部202に接続されており、第2中間熱交換器212の冷媒側流路の一端の冷媒出入口αと接続部202の間に第2中継膨張弁272が設けられる。第2中間熱交換器212の冷媒側流路の他端の冷媒出入口jは、第2冷媒回路切換部222に接続されている。第2冷媒回路切換部222は各々の一端が一点で接続された三本の冷媒配管222a、222b、222cと三本の冷媒配管のうちの二本222b、222cのそれぞれに設けられた電磁弁282b、282cで形成される。そのうち一本の配管222aの他端は上述のように第2中間熱交換器の冷媒側流路の他端の冷媒出入口jに、もう一本の配管222bの他端は接続部203に、残りの一本の配管222cの他端は接続部201に接続されている。配管222bには電磁弁282bが設けられ、配管222cには電磁弁282cが設けられる。電磁弁282bと電磁弁282cの一方を開けて、他方を閉じることで冷媒の流れを切り換えている。なお、本実施形態の第1冷媒回路切換部221と第2冷媒回路切換部222はこれに限定したものではなく、三方弁より構成されてもよい。   The refrigerant inlet / outlet α at one end of the refrigerant side flow path of the second intermediate heat exchanger 212 is also connected to the connection portion 202, and is connected to the refrigerant inlet / outlet α at one end of the refrigerant side flow path of the second intermediate heat exchanger 212. A second relay expansion valve 272 is provided between 202. The refrigerant inlet / outlet j at the other end of the refrigerant side flow path of the second intermediate heat exchanger 212 is connected to the second refrigerant circuit switching unit 222. The second refrigerant circuit switching unit 222 includes three refrigerant pipes 222a, 222b, and 222c each having one end connected at one point, and two solenoid valves 282b provided on two of the three refrigerant pipes 222b and 222c. , 282c. Of these, the other end of one pipe 222a remains at the refrigerant inlet / outlet j at the other end of the refrigerant side flow path of the second intermediate heat exchanger, and the other end of the other pipe 222b remains at the connection portion 203 as described above. The other end of the single pipe 222c is connected to the connecting portion 201. The piping 222b is provided with an electromagnetic valve 282b, and the piping 222c is provided with an electromagnetic valve 282c. The refrigerant flow is switched by opening one of the electromagnetic valve 282b and the electromagnetic valve 282c and closing the other. In addition, the 1st refrigerant circuit switching part 221 and the 2nd refrigerant circuit switching part 222 of this embodiment are not limited to this, You may be comprised from a three-way valve.

熱媒体回路30においては、第1中間熱交換器211の熱媒体側流路の一端の熱媒体入口hは第1ポンプ231に接続されている。この第1ポンプ231は熱媒体を循環させるためのものである。一方、第1中間熱交換器211の熱媒体側流路の他端の熱媒体出口gに接続された熱媒体配管571には熱媒体配管511と熱媒体配管512と熱媒体配管513が接続されている。熱媒体配管511は流量調整弁251と熱媒体配管581を介して接続部291に、熱媒体配管512は流量調整弁255と熱媒体配管583を介して接続部293に、熱媒体配管513は流量調整弁259と熱媒体配管585を介して接続部295に接続されている。   In the heat medium circuit 30, the heat medium inlet h at one end of the heat medium side flow path of the first intermediate heat exchanger 211 is connected to the first pump 231. The first pump 231 is for circulating the heat medium. On the other hand, a heat medium pipe 511, a heat medium pipe 512, and a heat medium pipe 513 are connected to the heat medium pipe 571 connected to the heat medium outlet g at the other end of the heat medium side flow path of the first intermediate heat exchanger 211. ing. The heat medium pipe 511 is connected to the connection part 291 via the flow rate adjustment valve 251 and the heat medium pipe 581, the heat medium pipe 512 is connected to the connection part 293 via the flow rate adjustment valve 255 and the heat medium pipe 583, and the heat medium pipe 513 is flow rate. It is connected to the connection part 295 via the regulating valve 259 and the heat medium pipe 585.

第2中間熱交換器212の熱媒体側流路の一端の熱媒体入口lは第2ポンプ232に接続されている。この第2ポンプ232も熱媒体を循環させるためのものである。一方、第2中間熱交換器212の熱媒体側流路の他端の熱媒体出口kに接続された熱媒体配管573には熱媒体配管521と熱媒体配管522と熱媒体配管523が接続されている。熱媒体配管521は流量調整弁252と熱媒体配管581を介して接続部291に、熱媒体配管522は流量調整弁256と熱媒体配管583を介して接続部293に、熱媒体配管523は流量調整弁260と熱媒体配管585を介して接続部295に接続されている。   The heat medium inlet l at one end of the heat medium side flow path of the second intermediate heat exchanger 212 is connected to the second pump 232. The second pump 232 is also for circulating the heat medium. On the other hand, a heat medium pipe 521, a heat medium pipe 522, and a heat medium pipe 523 are connected to the heat medium pipe 573 connected to the heat medium outlet k at the other end of the heat medium side flow path of the second intermediate heat exchanger 212. ing. The heat medium pipe 521 is connected to the connection part 291 via the flow rate adjustment valve 252 and the heat medium pipe 581, the heat medium pipe 522 is connected to the connection part 293 via the flow rate adjustment valve 256 and the heat medium pipe 583, and the heat medium pipe 523 is flow rate. The control valve 260 and the heat medium pipe 585 are connected to the connection portion 295.

第1ポンプ231の流出口mは上述のように第1中間熱交換器211の熱媒体側流路の一端の熱媒体入口hに接続されている。第1ポンプ231の流入口nに接続された熱媒体配管572には熱媒体配管531と熱媒体配管532と熱媒体配管533が接続されている。熱媒体配管531は流量調整弁253と熱媒体配管582を介して接続部292に、熱媒体配管532は流量調整弁257と熱媒体配管584を介して接続部294に、熱媒体配管533は流量調整弁261と熱媒体配管586を介して接続部296に接続されている。   The outlet m of the first pump 231 is connected to the heat medium inlet h at one end of the heat medium side flow path of the first intermediate heat exchanger 211 as described above. A heat medium pipe 531, a heat medium pipe 532, and a heat medium pipe 533 are connected to the heat medium pipe 572 connected to the inlet n of the first pump 231. The heat medium pipe 531 is connected to the connection part 292 via the flow rate adjustment valve 253 and the heat medium pipe 582, the heat medium pipe 532 is connected to the connection part 294 via the flow rate adjustment valve 257 and the heat medium pipe 584, and the heat medium pipe 533 is flow rate. The adjustment valve 261 and the heat medium pipe 586 are connected to the connection portion 296.

第2ポンプ232の流出口oは上述のように第2中間熱交換器212の熱媒体側流路の一端の熱媒体入口lに接続されている。第2ポンプ232の流入口pに接続された熱媒体配管574には熱媒体配管541と熱媒体配管542と熱媒体配管543が接続されている。熱媒体配管541は流量調整弁254と熱媒体配管582を介して接続部292に、熱媒体配管542は流量調整弁258と熱媒体配管584を介して接続部294に、熱媒体配管543は流量調整弁262と熱媒体配管586を介して接続部296に接続されている。   The outlet o of the second pump 232 is connected to the heat medium inlet l at one end of the heat medium side flow path of the second intermediate heat exchanger 212 as described above. A heat medium pipe 541, a heat medium pipe 542, and a heat medium pipe 543 are connected to the heat medium pipe 574 connected to the inlet p of the second pump 232. The heat medium pipe 541 is connected to the connection portion 292 via the flow rate adjustment valve 254 and the heat medium pipe 582, the heat medium pipe 542 is connected to the connection portion 294 via the flow rate adjustment valve 258 and the heat medium pipe 584, and the heat medium pipe 543 is flow rate. It is connected to the connection part 296 via the regulating valve 262 and the heat medium pipe 586.

第1熱媒体回路切換部223aは、各々の一端が一点で接続された熱媒体配管511、521、581と三本の熱媒体配管のうちの二本の熱媒体配管511、521のそれぞれに設けられた流量調整弁251と流量調整弁252で形成される。そのうち二本の熱媒体配管511、521の他端は上述のように熱媒体配管571に、残りの熱媒体配管581の他端は接続部291に接続されている。第1熱媒体回路切換部223aは、第1ポンプ231と第1中間熱交換器211の熱媒体側流路と後述する室内熱交換器310a〜310cが接続される第1熱媒体回路と、第2ポンプ232と第2中間熱交換器212の熱媒体側流路と後述する室内熱交換器310a〜310cが接続される第2熱媒体回路のいずれか一方を確立することができる。第1熱媒体回路切換部223b、223cと第2熱媒体回路切換部224a、224b、224cも同様に3本の熱媒体配管と2つの流量調整弁より構成され、第1熱媒体回路と第2熱媒体回路のいずれか一方を確立することができる。なお、本実施形態の第1熱媒体回路切換部223a、223b、223cと第2熱媒体回路切換部224a、224b、224cはこの構成に限定されたものではなく、三方弁より構成されてもよい。なお、第1熱媒体切換部223a〜223cと第2熱媒体切換部224a〜224cを総称して熱媒体切換部という。   The first heat medium circuit switching unit 223a is provided in each of the heat medium pipes 511, 521, 581 and one of the three heat medium pipes 511, 521 of which one end is connected at one point. The flow rate adjusting valve 251 and the flow rate adjusting valve 252 are formed. The other end of the two heat medium pipes 511 and 521 is connected to the heat medium pipe 571 as described above, and the other end of the remaining heat medium pipe 581 is connected to the connection portion 291. The first heat medium circuit switching unit 223a includes a first heat medium circuit to which a heat medium side flow path of the first pump 231 and the first intermediate heat exchanger 211 and indoor heat exchangers 310a to 310c described later are connected, One of the 2nd heat medium circuit to which the heat medium side flow path of 2 pump 232 and the 2nd intermediate heat exchanger 212 and indoor heat exchangers 310a-310c mentioned below are connected can be established. Similarly, the first heat medium circuit switching units 223b and 223c and the second heat medium circuit switching units 224a, 224b and 224c are also configured by three heat medium pipes and two flow rate adjusting valves, and the first heat medium circuit and the second heat medium circuit Either one of the heat carrier circuits can be established. The first heat medium circuit switching units 223a, 223b, and 223c and the second heat medium circuit switching units 224a, 224b, and 224c of the present embodiment are not limited to this configuration, and may be configured by a three-way valve. . The first heat medium switching units 223a to 223c and the second heat medium switching units 224a to 224c are collectively referred to as a heat medium switching unit.

3台の室内機300a〜300cは、主に、室内熱交換器310a〜310cと、室内ファン320a〜320cとを備えている。なお、室内機300a〜300cの構成は全て同じであるため、以下の説明では、室内機300aの構成についてのみ説明を行い、その他の室内機300b〜300cについては説明を省略する。   The three indoor units 300a to 300c mainly include indoor heat exchangers 310a to 310c and indoor fans 320a to 320c. In addition, since all the configurations of the indoor units 300a to 300c are the same, in the following description, only the configuration of the indoor unit 300a will be described, and description of the other indoor units 300b to 300c will be omitted.

室内機300aは、熱媒体配管501と接続される接続部331aと、熱媒体配管502と接続される接続部332aを備えている。室内熱交換器310aは、一方の熱媒体入口qが接続部331aに、他方の熱媒体出口rが接続部332aに、それぞれ熱媒体配管551a、552aで接続されている。室内ファン320aは、図示しないファンモータによって回転することで、室内機300a内に室内空気を取り込み、室内熱交換器310aにおいて熱媒体と室内空気とを熱交換させた後、室内へ供給する。   The indoor unit 300a includes a connection portion 331a connected to the heat medium pipe 501 and a connection portion 332a connected to the heat medium pipe 502. In the indoor heat exchanger 310a, one heat medium inlet q is connected to the connection portion 331a, and the other heat medium outlet r is connected to the connection portion 332a through heat medium pipes 551a and 552a, respectively. The indoor fan 320a is rotated by a fan motor (not shown), thereby taking in indoor air into the indoor unit 300a, exchanging heat between the heat medium and the indoor air in the indoor heat exchanger 310a, and supplying the indoor air to the room.

以上説明した構成によって、典型例の空気調和装置1の冷媒回路20および熱媒体回路30が形成され、冷媒回路20に冷媒を流し、第1中間熱交換器211または第2中間熱交換器212で冷媒と熱媒体が熱交換され、熱媒体回路30に熱媒体を流すことによって冷凍サイクルが成立する。   With the configuration described above, the refrigerant circuit 20 and the heat medium circuit 30 of the air conditioner 1 of the typical example are formed, and the refrigerant flows through the refrigerant circuit 20, and the first intermediate heat exchanger 211 or the second intermediate heat exchanger 212 The refrigerant and the heat medium are heat-exchanged, and the heat medium is caused to flow through the heat medium circuit 30 to establish a refrigeration cycle.

<冷房運転>
次に、本典型例の空気調和装置1の冷房運転時の動作について説明する。
ここでは、室内機300a〜300c全てが冷房運転を行う場合の空気調和装置1の動作を図1を用いて説明する。四方弁120を実線で示す状態、すなわち、ポートaとポートbが連通するよう、また、ポートcとポートdが連通するよう、切り換える。また、電磁弁281bと電磁弁282bは開けられ、電磁弁281cと電磁弁282cは閉じられる。これにより、室外熱交換器130が凝縮器として機能するとともに、第1中間熱交換器211と第2中間熱交換器212が蒸発器として機能する。さらに、流量調整弁251、253、255、257、260、262は開けられ、流量調整弁252、254、256、258、259、261は閉じられる。
<Cooling operation>
Next, the operation | movement at the time of the cooling operation of the air conditioning apparatus 1 of this typical example is demonstrated.
Here, operation | movement of the air conditioning apparatus 1 in case all the indoor units 300a-300c perform air_conditionaing | cooling operation is demonstrated using FIG. The four-way valve 120 is switched to a state indicated by a solid line, that is, the port a and the port b communicate with each other, and the port c and the port d communicate with each other. Further, the electromagnetic valve 281b and the electromagnetic valve 282b are opened, and the electromagnetic valve 281c and the electromagnetic valve 282c are closed. Thereby, the outdoor heat exchanger 130 functions as a condenser, and the first intermediate heat exchanger 211 and the second intermediate heat exchanger 212 function as an evaporator. Further, the flow rate adjustment valves 251, 253, 255, 257, 260, 262 are opened, and the flow rate adjustment valves 252, 254, 256, 258, 259, 261 are closed.

冷媒回路20が上述の状態となっているとき、室外機100内にある圧縮機110で圧縮され吐出された高圧の冷媒は、四方弁120を介して室外熱交換器130に流入する。室外熱交換器130に流入した冷媒は室外空気に放熱し、冷却される。冷却された冷媒は室外膨張弁150を通過して、閉鎖弁102を介して室外機100から流出し、液管430に流入する。液管430に流入した冷媒は接続部202を介して中継ユニット200に流入する。中継ユニット200内に流入した冷媒は第2分岐点602で分流する。上記でいう冷却とは、状態変化(相変化)を伴う冷媒または熱媒体の場合は凝縮し、状態変化(相変化)を伴わない冷媒または熱媒体の場合は温度が下がることを示している。以下に記載する冷却についても冷媒および熱媒体共に同じものである。   When the refrigerant circuit 20 is in the above-described state, the high-pressure refrigerant compressed and discharged by the compressor 110 in the outdoor unit 100 flows into the outdoor heat exchanger 130 via the four-way valve 120. The refrigerant flowing into the outdoor heat exchanger 130 dissipates heat to the outdoor air and is cooled. The cooled refrigerant passes through the outdoor expansion valve 150, flows out of the outdoor unit 100 through the closing valve 102, and flows into the liquid pipe 430. The refrigerant that has flowed into the liquid pipe 430 flows into the relay unit 200 through the connection portion 202. The refrigerant flowing into the relay unit 200 is diverted at the second branch point 602. The cooling mentioned above indicates that the refrigerant or the heat medium accompanied by a state change (phase change) is condensed, and the temperature is lowered in the case of the refrigerant or the heat medium not accompanied by a state change (phase change). The cooling and heat medium described below are the same for the cooling described below.

分流した冷媒のうち一方の冷媒は第1中継膨張弁271に流入し、減圧される。減圧された冷媒は第1中間熱交換器211で熱媒体から吸熱し、加熱される。加熱された冷媒は電磁弁281bを通過し、接続部203を介して中継ユニット200から流出し、低圧ガス管420に流入する。上記でいう加熱とは、状態変化(相変化)を伴う冷媒または熱媒体の場合は蒸発し、状態変化(相変化)を伴わない冷媒または熱媒体の場合は温度が上がることを示している。以下に記載する加熱についても冷媒および熱媒体共に同じものである。   One of the divided refrigerant flows into the first relay expansion valve 271 and is depressurized. The decompressed refrigerant absorbs heat from the heat medium in the first intermediate heat exchanger 211 and is heated. The heated refrigerant passes through the electromagnetic valve 281 b, flows out from the relay unit 200 through the connection portion 203, and flows into the low pressure gas pipe 420. The heating mentioned above indicates that the refrigerant or heat medium accompanied by a state change (phase change) evaporates, and the temperature rises in the case of a refrigerant or heat medium not accompanied by a state change (phase change). Regarding the heating described below, both the refrigerant and the heat medium are the same.

第2分岐点602で分流した冷媒のうち他方の冷媒は第2中継膨張弁272に流入し、減圧される。減圧された冷媒は第2中間熱交換器212で熱媒体から吸熱し、加熱される。加熱された冷媒は電磁弁282bを通過し、接続部203を介して中継ユニット200から流出し、低圧ガス管420に流入する。   Of the refrigerants branched at the second branch point 602, the other refrigerant flows into the second relay expansion valve 272 and is depressurized. The decompressed refrigerant absorbs heat from the heat medium in the second intermediate heat exchanger 212 and is heated. The heated refrigerant passes through the electromagnetic valve 282b, flows out of the relay unit 200 through the connection portion 203, and flows into the low-pressure gas pipe 420.

低圧ガス管420に流入した冷媒は、閉鎖弁103を介して室外機100に流入する。室外機100に流入した冷媒は圧縮機110に吸入されて再び圧縮される。以上説明したように冷媒回路20を冷媒が循環する。なお、第1中継膨張弁271と第2中継膨張弁272は各室内機の設定温度に応じて開度を同じにしてもよいし、異ならせてもよい。例えば、室内機300cの設定温度が室内機300a、300bの設定温度よりも高い場合は第2中継膨張弁272の開度を第1中継膨張弁271の開度よりも絞ることで、第2中間熱交換器212に流入する冷媒の流量を第1中間熱交換器211に流入する冷媒の流量よりも少なくして、第2中間熱交換器212を通過した熱媒体の冷却を抑えることで、室内熱交換器310cで熱交換される熱量を少なくできる。   The refrigerant that has flowed into the low-pressure gas pipe 420 flows into the outdoor unit 100 through the closing valve 103. The refrigerant flowing into the outdoor unit 100 is sucked into the compressor 110 and compressed again. As described above, the refrigerant circulates through the refrigerant circuit 20. Note that the first relay expansion valve 271 and the second relay expansion valve 272 may have the same opening degree or different degrees depending on the set temperature of each indoor unit. For example, when the set temperature of the indoor unit 300c is higher than the set temperature of the indoor units 300a and 300b, the opening of the second relay expansion valve 272 is reduced more than the opening of the first relay expansion valve 271, thereby By reducing the flow rate of the refrigerant flowing into the heat exchanger 212 below the flow rate of the refrigerant flowing into the first intermediate heat exchanger 211, the cooling of the heat medium that has passed through the second intermediate heat exchanger 212 is suppressed, The amount of heat exchanged by the heat exchanger 310c can be reduced.

<低負荷冷房運転>
典型例の空気調和装置1は、全体として3台の室内機300a、300b、300cの同時運転に対応できる能力を有するため、例えば、3台の室内機300a、300b、300cのうち1台の室内機300aが冷房運転を行い、残る2台の室内機300b、200cが運転停止状態にあるような低負荷冷房運転を行う時は、圧縮機110の回転数、第1中継膨張弁271の開度、第1ポンプ231の回転数や、第2中継膨張弁272を閉じて第2ポンプ232を止めて第1中間熱交換器211だけを使用するなどの調整といった典型的な対応では能力調整が追いつかず、能力過多となって熱媒体の温度が低下しすぎる可能性がある。熱媒体の温度が低下しすぎてしまった場合、熱交換器や熱媒体の氷結保護機能においてシステム停止(圧縮機停止)が頻発するという問題があった。
<Low-load cooling operation>
Since the air conditioner 1 of a typical example has the capability to cope with the simultaneous operation of the three indoor units 300a, 300b, and 300c as a whole, for example, one indoor unit among the three indoor units 300a, 300b, and 300c. When the air conditioner 300a performs the cooling operation and the remaining two indoor units 300b and 200c perform the low-load cooling operation such that the operation is stopped, the rotational speed of the compressor 110 and the opening degree of the first relay expansion valve 271 are performed. The typical adjustment such as the rotation speed of the first pump 231 or the adjustment of closing the second relay expansion valve 272 and stopping the second pump 232 to use only the first intermediate heat exchanger 211 catches up with the capacity adjustment. However, there is a possibility that the temperature of the heat medium is excessively lowered due to excessive capacity. When the temperature of the heat medium is excessively lowered, there has been a problem that system stoppage (compressor stoppage) frequently occurs in the heat exchanger and the ice protection function of the heat medium.

図2は、低負荷冷房運転時の能力過多を抑制することが可能な本発明に係る一実施形態の空気調和装置1Aの構成を示す回路図である。
本実施形態の空気調和装置1Aでは、低負荷冷房運転時、一方の中間熱交換器を蒸発器として機能させ、他方の中間熱交換器を凝縮器として機能させる。図2では、第1中間熱交換器211を蒸発器として機能させ、第2中間熱交換器212を凝縮器として機能させる場合を示している。なお、第2中間熱交換器212を蒸発器として機能させ、第1中間熱交換器211を凝縮器として機能させてもよい。流量調整弁251、253は開けられ、流量調整弁252、254、255、256、257、258、259、260、261は閉じられる。
FIG. 2 is a circuit diagram showing a configuration of an air-conditioning apparatus 1A according to an embodiment of the present invention that can suppress excessive capacity during low-load cooling operation.
In the air conditioner 1A of the present embodiment, during the low-load cooling operation, one intermediate heat exchanger functions as an evaporator, and the other intermediate heat exchanger functions as a condenser. FIG. 2 shows a case where the first intermediate heat exchanger 211 functions as an evaporator and the second intermediate heat exchanger 212 functions as a condenser. Note that the second intermediate heat exchanger 212 may function as an evaporator, and the first intermediate heat exchanger 211 may function as a condenser. The flow rate adjusting valves 251 and 253 are opened, and the flow rate adjusting valves 252, 254, 255, 256, 257, 258, 259, 260, and 261 are closed.

この空気調和装置1Aには、低負荷冷房運転時に、第2熱媒体回路において室内熱交換器を流通させることなく第2ポンプ232および第2中間熱交換器212に熱媒体を循環させるバイパス回路25と、このバイパス回路25に設けられ、バイパス回路25を循環する熱媒体と第1熱媒体回路を循環する熱媒体との間で熱交換させる熱媒体間熱交換器701が設けられている。この空気調和装置1Aにおけるその他の部分の構成は、上記の典型例の空気調和装置1と同様である。   The air conditioner 1A includes a bypass circuit 25 that circulates the heat medium to the second pump 232 and the second intermediate heat exchanger 212 without circulating the indoor heat exchanger in the second heat medium circuit during low-load cooling operation. And a heat exchanger related to heat medium 701 that exchanges heat between the heat medium circulating in the bypass circuit 25 and the heat medium circulating in the first heat medium circuit. The structure of the other part in this air conditioning apparatus 1A is the same as that of the air conditioning apparatus 1 of the above typical example.

次に、バイパス回路25の構成をより詳細に説明する。
熱媒体間熱交換器701は、内部に第1熱媒体が流通する第1熱媒体側流路と、第2熱媒体が流通する第2熱媒体側流路を備え、第1熱媒体入口w、第1熱媒体出口x、第2熱媒体入口yおよび第2熱媒体出口zを有する。熱媒体間熱交換器701の第1熱媒体入口wは第1ポンプ231の熱媒体出口mと接続され、熱媒体間熱交換器701の第1熱媒体出口xは第1中間熱交換器211の熱媒体入口hと接続されている。第2中間熱交換器212の熱媒体出口kに接続された熱媒体配管573には、バイパス用の熱媒体配管703が分岐点704で接続され、バイパス用の熱媒体配管703には流量調整弁702を通じて熱媒体間熱交換器701の第2熱媒体入口yが接続されている。熱媒体間熱交換器701の第2熱媒体出口zは、バイパス用の熱媒体配管705を通じて熱媒体配管574と合流点706で接続されている。
Next, the configuration of the bypass circuit 25 will be described in more detail.
The heat exchanger related to heat medium 701 includes a first heat medium side flow path through which the first heat medium flows and a second heat medium side flow path through which the second heat medium flows, and includes a first heat medium inlet w. , A first heat medium outlet x, a second heat medium inlet y, and a second heat medium outlet z. The first heat medium inlet w of the heat exchanger related to heat medium 701 is connected to the heat medium outlet m of the first pump 231, and the first heat medium outlet x of the heat exchanger related to heat medium 701 is connected to the first intermediate heat exchanger 211. Connected to the heat medium inlet h. A bypass heat medium pipe 703 is connected to the heat medium pipe 573 connected to the heat medium outlet k of the second intermediate heat exchanger 212 at a branch point 704, and a flow rate adjusting valve is connected to the bypass heat medium pipe 703. A second heat medium inlet y of the heat exchanger related to heat medium 701 is connected through 702. The second heat medium outlet z of the heat exchanger related to heat medium 701 is connected to the heat medium pipe 574 and a junction 706 through a heat medium pipe 705 for bypass.

<低負荷冷房運転時の動作>
低負荷冷房運転の例として、室内機300b、300cを停止状態として室内機300aのみを冷房運転させる場合の空気調和装置1Aの動作について説明する。
四方弁120を実線で示す状態、すなわち、ポートaとポートbが連通するよう、また、ポートcとポートdが連通するよう、切り換える。また、電磁弁281bと電磁弁282cが開けられ、電磁弁281cと電磁弁282bが閉じられる。これにより、室外熱交換器130と第2中間熱交換器212が凝縮器と機能し、第1中間熱交換器211が蒸発器として機能する。さらに、流量調整弁251、253が開けられ、流量調整弁252、254が閉じられる。
<Operation during low-load cooling operation>
As an example of the low-load cooling operation, the operation of the air conditioner 1A when the indoor units 300b and 300c are stopped and only the indoor unit 300a is cooled will be described.
The four-way valve 120 is switched to a state indicated by a solid line, that is, the port a and the port b communicate with each other, and the port c and the port d communicate with each other. Further, the electromagnetic valve 281b and the electromagnetic valve 282c are opened, and the electromagnetic valve 281c and the electromagnetic valve 282b are closed. Thereby, the outdoor heat exchanger 130 and the second intermediate heat exchanger 212 function as a condenser, and the first intermediate heat exchanger 211 functions as an evaporator. Further, the flow rate adjustment valves 251 and 253 are opened, and the flow rate adjustment valves 252 and 254 are closed.

冷媒回路20が上述の状態となっているとき、室外機100内にある圧縮機110で圧縮され吐出された高圧の冷媒は、第1分岐点601で二つに分岐する。分岐した冷媒のうち一方の冷媒は、四方弁120を介して室外熱交換器130に流入する。室外熱交換器130に流入した冷媒は室外空気に放熱し、冷却される。冷却された冷媒は室外膨張弁150で高圧から中間圧の間の圧力まで減圧される。減圧された冷媒は閉鎖弁102を介して室外機100から流出し、液管430に流入する。液管430に流入した冷媒は接続部202を介して中継ユニット200に流入する。   When the refrigerant circuit 20 is in the above-described state, the high-pressure refrigerant compressed and discharged by the compressor 110 in the outdoor unit 100 branches into two at the first branch point 601. One of the branched refrigerants flows into the outdoor heat exchanger 130 via the four-way valve 120. The refrigerant flowing into the outdoor heat exchanger 130 dissipates heat to the outdoor air and is cooled. The cooled refrigerant is depressurized by the outdoor expansion valve 150 from a high pressure to an intermediate pressure. The decompressed refrigerant flows out of the outdoor unit 100 through the closing valve 102 and flows into the liquid pipe 430. The refrigerant that has flowed into the liquid pipe 430 flows into the relay unit 200 through the connection portion 202.

中継ユニット200内に流入した冷媒は第2分岐点602で後述する第2中間熱交換器212を通過した冷媒と合流する。合流した冷媒は第1中継膨張弁271に流入し、減圧される。減圧された冷媒は第1中間熱交換器211で、第2熱媒体回路側の熱媒体流路を流れる熱媒体から吸熱し、加熱される。加熱された冷媒は電磁弁281bを通過し、接続部203を介して中継ユニット200から流出し、低圧ガス管420に流入する。   The refrigerant that has flowed into the relay unit 200 merges with the refrigerant that has passed through the second intermediate heat exchanger 212 described later at the second branch point 602. The merged refrigerant flows into the first relay expansion valve 271 and is depressurized. The decompressed refrigerant is heated by the first intermediate heat exchanger 211 by absorbing heat from the heat medium flowing through the heat medium flow path on the second heat medium circuit side. The heated refrigerant passes through the electromagnetic valve 281 b, flows out from the relay unit 200 through the connection portion 203, and flows into the low pressure gas pipe 420.

一方、室外機100内の第1分岐点601で分岐された他方の冷媒は、閉鎖弁101を介して室外機100から流出する。室外機100から流出した冷媒は高圧ガス管410を通過して接続部201を介して中継ユニット200に流入する。中継ユニット200内に流入した冷媒は電磁弁282cを介して第2中間熱交換器212に流入する。第2中間熱交換器212に流入した冷媒は熱媒体に放熱し、冷却される。冷却された冷媒は第2中継膨張弁272を通過して第2分岐点602で、室外機100から液管430を通じて流入してきた冷媒と合流し、第1中継膨張弁271を通過して第1中間熱交換器211に流入する。   On the other hand, the other refrigerant branched at the first branch point 601 in the outdoor unit 100 flows out of the outdoor unit 100 via the closing valve 101. The refrigerant that has flowed out of the outdoor unit 100 passes through the high-pressure gas pipe 410 and flows into the relay unit 200 via the connection unit 201. The refrigerant flowing into the relay unit 200 flows into the second intermediate heat exchanger 212 via the electromagnetic valve 282c. The refrigerant flowing into the second intermediate heat exchanger 212 dissipates heat to the heat medium and is cooled. The cooled refrigerant passes through the second relay expansion valve 272 and merges with the refrigerant flowing in from the outdoor unit 100 through the liquid pipe 430 at the second branch point 602, passes through the first relay expansion valve 271, and passes through the first relay expansion valve 271. It flows into the intermediate heat exchanger 211.

低圧ガス管420に流入した冷媒は、閉鎖弁103を介して室外機100に流入する。室外機100に流入した冷媒は圧縮機110に吸入されて再び圧縮される。以上説明したように冷媒回路20を冷媒が循環する。   The refrigerant that has flowed into the low-pressure gas pipe 420 flows into the outdoor unit 100 through the closing valve 103. The refrigerant flowing into the outdoor unit 100 is sucked into the compressor 110 and compressed again. As described above, the refrigerant circulates through the refrigerant circuit 20.

次に、熱媒体回路30の動作を説明する。
第1熱媒体回路において、第1ポンプ231から流出した熱媒体は熱媒体間熱交換器701にてバイパス回路25側の熱媒体流路を流れる熱媒体から吸熱して加熱され、第1中間熱交換器211に流入する。第1中間熱交換器211に流入した熱媒体は冷媒に放熱し、冷却される。冷却された熱媒体は第1熱媒体回路切換部223aを通過し、接続部291を介して中継ユニット200から流出する。中継ユニット200から流出した熱媒体は熱媒体配管501を通過して接続部331aを介して室内機300aに流入する。室内機300aに流入した熱媒体は熱媒体配管551aを介して室内熱交換器310aに流入する。室内熱交換器310aに流入した熱媒体は室内空気より吸熱し、加熱される。加熱された熱媒体は熱媒体配管552aを通過して、接続部332aを介して室内機300aから流出する。室内機300aから流出した熱媒体は熱媒体配管502を通過して、接続部292を介して中継ユニット200に流入する。中継ユニット200に流入した熱媒体は第2熱媒体回路切換部224aを介して第1ポンプ231に戻る。
Next, the operation of the heat medium circuit 30 will be described.
In the first heat medium circuit, the heat medium flowing out from the first pump 231 is heated by absorbing heat from the heat medium flowing through the heat medium flow path on the bypass circuit 25 side in the heat exchanger related to heat medium 701, and is heated. It flows into the exchanger 211. The heat medium flowing into the first intermediate heat exchanger 211 dissipates heat to the refrigerant and is cooled. The cooled heat medium passes through the first heat medium circuit switching unit 223a and flows out of the relay unit 200 through the connection unit 291. The heat medium flowing out from the relay unit 200 passes through the heat medium pipe 501 and flows into the indoor unit 300a through the connection portion 331a. The heat medium flowing into the indoor unit 300a flows into the indoor heat exchanger 310a via the heat medium pipe 551a. The heat medium flowing into the indoor heat exchanger 310a absorbs heat from the indoor air and is heated. The heated heat medium passes through the heat medium pipe 552a and flows out of the indoor unit 300a through the connection portion 332a. The heat medium flowing out from the indoor unit 300 a passes through the heat medium pipe 502 and flows into the relay unit 200 through the connection portion 292. The heat medium flowing into the relay unit 200 returns to the first pump 231 via the second heat medium circuit switching unit 224a.

一方、バイパス回路25において、第2ポンプ232から流出した熱媒体は第2中間熱交換器212に流入する。第2中間熱交換器212に流入した熱媒体は冷媒から吸熱し、加熱される。加熱された熱媒体はバイパス用の熱媒体配管703、流量調整弁702を介して熱媒体間熱交換器701に流入し、第1熱媒体回路側の熱媒体流路を流れる熱媒体に放熱し、冷却される。熱媒体間熱交換器701より流出した熱媒体はバイパス用の熱媒体配管705、熱媒体配管574を通じて第2ポンプ232に戻る。以上のように熱媒体回路30を熱媒体が循環する。   On the other hand, in the bypass circuit 25, the heat medium flowing out from the second pump 232 flows into the second intermediate heat exchanger 212. The heat medium flowing into the second intermediate heat exchanger 212 absorbs heat from the refrigerant and is heated. The heated heat medium flows into the heat exchanger related to heat medium 701 via the heat medium pipe 703 for bypass and the flow rate adjusting valve 702, and dissipates heat to the heat medium flowing through the heat medium flow path on the first heat medium circuit side. Cooled down. The heat medium flowing out from the heat exchanger related to heat medium 701 returns to the second pump 232 through the heat medium pipe 705 for bypass and the heat medium pipe 574. As described above, the heat medium circulates through the heat medium circuit 30.

このように、本実施形態の空気調和装置1Aでは、低負荷冷房運転時に中継ユニット200内の第1中間熱交換器211を蒸発器として機能させ、第2中間熱交換器212を凝縮器として機能させ、バイパス回路25を循環する熱媒体と第1熱媒体回路を循環する熱媒体との間で熱交換させることによって、第1熱媒体回路を循環する熱媒体の温度が低下しすぎることを防止することができ、システム停止(圧縮機停止)を回避することができる。   Thus, in the air conditioner 1A of the present embodiment, the first intermediate heat exchanger 211 in the relay unit 200 functions as an evaporator and the second intermediate heat exchanger 212 functions as a condenser during low-load cooling operation. And heat exchange between the heat medium circulating in the bypass circuit 25 and the heat medium circulating in the first heat medium circuit prevents the temperature of the heat medium circulating in the first heat medium circuit from excessively decreasing. System stop (compressor stop) can be avoided.

<変形例>
低負荷冷房運転として、3台の室内機300a、300b、300cのうち1台の室内機300aが冷房運転を行い、残る2台の室内機300b、200cが運転停止状態にある運転状況を例示したが、3台の室内機300a、300b、300cのうち2台の室内機300a、300bが冷房運転を行い、残る1台の室内機300cが運転停止状態にある運転状況を低負荷冷房運転として、熱媒体間熱交換器701で、バイパス回路25を循環する熱媒体と第1熱媒体回路を循環する熱媒体との間で熱交換させてもよい。
<Modification>
As an example of the low-load cooling operation, an operation situation is illustrated in which one of the three indoor units 300a, 300b, and 300c performs the cooling operation, and the remaining two indoor units 300b and 200c are in the operation stop state. However, of the three indoor units 300a, 300b, 300c, the two indoor units 300a, 300b perform the cooling operation, and the operation state in which the remaining one indoor unit 300c is stopped is referred to as a low-load cooling operation. The heat exchanger between heat medium 701 may exchange heat between the heat medium circulating in the bypass circuit 25 and the heat medium circulating in the first heat medium circuit.

上記の実施形態では、中継ユニット200に2つの中間熱交換器211、212が設けられる場合を説明したが、中継ユニット200に3つの中間熱交換器が設けられていてもよく、2つの中間熱交換器を蒸発器として機能させ、残り1つの中間熱交換器を凝縮器として機能させてもよい。あるいは、2つの中間熱交換器を凝縮器として機能させ、残り1つの中間熱交換器を蒸発器として機能させてもよい。   In the above embodiment, the case where two intermediate heat exchangers 211 and 212 are provided in the relay unit 200 has been described. However, three intermediate heat exchangers may be provided in the relay unit 200, and two intermediate heat exchangers may be provided. The exchanger may function as an evaporator, and the remaining one intermediate heat exchanger may function as a condenser. Alternatively, two intermediate heat exchangers may function as a condenser, and the remaining one intermediate heat exchanger may function as an evaporator.

その他、本発明は、上述の実施形態および変形例に限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。   In addition, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the scope of the present invention.

1A…空気調和装置
20…冷媒回路
25…バイパス回路
30…熱媒体回路
100…室外機
110…圧縮機
120…四方弁
130…室外熱交換器
150…室外膨張弁
200…中継ユニット
211…第1中間熱交換器
212…第2中間熱交換器
221…第1冷媒回路切換部
222…第2冷媒回路切換部
223a〜223c…第1熱媒体回路切換部
224a〜224c…第2熱媒体回路切換部
231…第1ポンプ
232…第2ポンプ
300a〜300c…室内機
310a〜310c…室内熱交換器
410…高圧ガス管
420…低圧ガス管
430…液管
701…熱媒体間熱交換器
602…流量調整弁
603…バイパス用の熱媒体配管
DESCRIPTION OF SYMBOLS 1A ... Air conditioning apparatus 20 ... Refrigerant circuit 25 ... Bypass circuit 30 ... Heat medium circuit 100 ... Outdoor unit 110 ... Compressor 120 ... Four-way valve 130 ... Outdoor heat exchanger 150 ... Outdoor expansion valve 200 ... Relay unit 211 ... 1st middle Heat exchanger 212 ... second intermediate heat exchanger 221 ... first refrigerant circuit switching unit 222 ... second refrigerant circuit switching unit 223a to 223c ... first heat medium circuit switching unit 224a to 224c ... second heat medium circuit switching unit 231 ... 1st pump 232 ... 2nd pump 300a-300c ... Indoor unit 310a-310c ... Indoor heat exchanger 410 ... High-pressure gas pipe 420 ... Low-pressure gas pipe 430 ... Liquid pipe 701 ... Heat exchanger between heat media 602 ... Flow control valve 603 .. Heat medium piping for bypass

Claims (1)

圧縮機と室外熱交換器とを備えた室外機と、
前記室外機から引き出されたガス管と液管と、
冷媒側流路と熱媒体側流路を有する第1中間熱交換器と、
冷媒側流路と熱媒体側流路を有する第2中間熱交換器と、
第1ポンプと、
第2ポンプと、
室内熱交換器を有する複数の室内機と、
前記複数の室内熱交換器のそれぞれの両端に接続され、前記第1ポンプと前記第1中間熱交換器の熱媒体側流路と前記室内熱交換器が接続される第1熱媒体回路と、前記第2ポンプと前記第2中間熱交換器の熱媒体側流路と前記室内熱交換器が接続される第2熱媒体回路のいずれか一方を確立するための熱媒体回路切換部と、
前記室内熱交換器を流通させることなく前記第2ポンプおよび前記第2中間熱交換器に熱媒体を循環させるバイパス回路と、
前記バイパス回路に設けられ、前記バイパス回路を循環する熱媒体と前記第1熱媒体回路を循環する熱媒体との間で熱交換させる熱媒体間熱交換器と
を備え、
前記第1中間熱交換器の冷媒側流路の一端と、前記第2中間熱交換器の冷媒側流路の一端がそれぞれ前記ガス管に接続され、
前記第1中間熱交換器の冷媒側流路の他端と、前記第2中間熱交換器の冷媒側流路の他端がそれぞれ前記液管に接続され、
前記複数の室内機において一部の前記室内機の冷房運転のみを行う時、前記第1中間熱交換器を蒸発器として機能させるとともに、前記第2中間熱交換器を凝縮器として機能させるようにしたことを特徴とする空気調和装置。
An outdoor unit equipped with a compressor and an outdoor heat exchanger;
A gas pipe and a liquid pipe drawn from the outdoor unit;
A first intermediate heat exchanger having a refrigerant side flow path and a heat medium side flow path;
A second intermediate heat exchanger having a refrigerant side flow path and a heat medium side flow path;
A first pump;
A second pump;
A plurality of indoor units having an indoor heat exchanger;
A first heat medium circuit connected to both ends of each of the plurality of indoor heat exchangers, to which the first pump, the heat medium side flow path of the first intermediate heat exchanger, and the indoor heat exchanger are connected; A heat medium circuit switching unit for establishing any one of a heat medium side flow path of the second pump and the second intermediate heat exchanger and a second heat medium circuit to which the indoor heat exchanger is connected;
A bypass circuit for circulating a heat medium in the second pump and the second intermediate heat exchanger without circulating the indoor heat exchanger;
A heat exchanger between heat media that is provided in the bypass circuit and exchanges heat between the heat medium circulating in the bypass circuit and the heat medium circulating in the first heat medium circuit;
One end of the refrigerant side flow path of the first intermediate heat exchanger and one end of the refrigerant side flow path of the second intermediate heat exchanger are each connected to the gas pipe,
The other end of the refrigerant side flow path of the first intermediate heat exchanger and the other end of the refrigerant side flow path of the second intermediate heat exchanger are each connected to the liquid pipe,
When performing only a cooling operation of some of the indoor units in the plurality of indoor units, the first intermediate heat exchanger functions as an evaporator and the second intermediate heat exchanger functions as a condenser. An air conditioner characterized by that.
JP2017069971A 2017-03-31 2017-03-31 Air conditioner Pending JP2018173191A (en)

Priority Applications (1)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111156615A (en) * 2020-01-17 2020-05-15 珠海格力电器股份有限公司 Controller heat dissipation system based on two-stage compressor system and control method thereof
CN113531773A (en) * 2021-06-18 2021-10-22 宁波奥克斯电气股份有限公司 Multi-connected air conditioner fault detection method and device and multi-connected air conditioner

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111156615A (en) * 2020-01-17 2020-05-15 珠海格力电器股份有限公司 Controller heat dissipation system based on two-stage compressor system and control method thereof
CN111156615B (en) * 2020-01-17 2024-01-16 珠海格力电器股份有限公司 Controller heat dissipation system based on two-stage compressor system and control method thereof
CN113531773A (en) * 2021-06-18 2021-10-22 宁波奥克斯电气股份有限公司 Multi-connected air conditioner fault detection method and device and multi-connected air conditioner
CN113531773B (en) * 2021-06-18 2022-11-15 宁波奥克斯电气股份有限公司 Multi-connected air conditioner fault detection method and device and multi-connected air conditioner

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