WO2021036781A1

WO2021036781A1 - Multi-split air conditioning system

Info

Publication number: WO2021036781A1
Application number: PCT/CN2020/108425
Authority: WO
Inventors: 孙继国; 程绍江; 禚百田; 张锐钢; 王军
Original assignee: 青岛海尔空调电子有限公司; 海尔智家股份有限公司
Priority date: 2019-08-30
Filing date: 2020-08-11
Publication date: 2021-03-04
Also published as: CN112443903A; CN112443903B

Abstract

A multi-split air conditioning system, comprising a first heat exchanging coiled pipe (101), a second heat exchanging coiled pipe (201), and multiple indoor units (3). Refrigerants having different temperatures flow in the first heat exchanging coiled pipe (101) and the second heat exchanging coiled pipe (201); each indoor unit (3) comprises a heat exchanger and an air supply fan (4); the heat exchanger is connected to the first heat exchanging coiled pipe (101) by means of a first refrigerant input pipe (5) and a first refrigerant output pipe (6), so that the refrigerant in the first heat exchanging coiled pipe (101) can flow into the heat exchanger by means of the first refrigerant input pipe (5), and the refrigerant in the heat exchanger can flow into the first heat exchanging coiled pipe (101) by means of the first refrigerant output pipe (6). The first refrigerant input pipe (5) is provided with a first valve element (7), and the first valve element (7) is configured to adjust refrigerant flow of the first refrigerant input pipe (5). The heat exchanger is further connected to the second heat exchanging coiled pipe (201) by means of a second refrigerant input pipe (8) and a second refrigerant output pipe (9), so that the refrigerant in the second heat exchanging coiled pipe (201) can flow into the heat exchanger by means of the second refrigerant input pipe (8), and the refrigerant in the heat exchanger can flow into the second heat exchanging coiled pipe (201) by means of the second refrigerant output pipe (9). The second refrigerant input pipe (8) is provided with a second valve element (10), and the second valve element (10) is configured to adjust refrigerant flow of the second refrigerant input pipe (8). When the refrigerant temperature in the first heat exchanging coiled pipe (101) and the second heat exchanging coiled pipe (201) is different, the refrigerant flow flowing out of the first heat exchanging coiled pipe (101) and the refrigerant flow flowing out of the second heat exchanging coiled pipe (201) are respectively controlled by means of the first valve element (7) and the second valve element (10), and a ratio of the refrigerant flow having two different temperatures which simultaneously flows through the heat exchanger can be regulated, so that each heat exchanger has desired heat/cold transfer capacity in the case that the ratio of the refrigerant flow is set according to heat exchanging requirements of the heat exchangers, and thus each indoor unit (3) can set, according to respective heat exchanging requirements, the ratio of the refrigerants together flowing through the heat exchangers of the indoor units (3), thereby implementing independent heating or refrigerating of the indoor units (3).

Description

Multi-line air conditioning system

Technical field

The invention belongs to the technical field of air conditioners, and specifically relates to a multi-line air conditioning system.

Background technique

With the continuous improvement of people's living standards, people have also put forward higher and higher requirements for the living environment. In order to maintain a comfortable ambient temperature in medium and large places, the multi-connected air conditioning system has become an indispensable heat exchange device. In the current market, most of the indoor units of the multi-line central air conditioner are connected to the same refrigerant circuit in parallel, so as to connect the outdoor unit through the refrigerant circuit. In this case, when some indoor units are in cooling or heating mode, the other indoor units can only choose the same operation mode or not run, but cannot choose different modes, that is, all indoor units can only run the same heating/cooling mode , It is impossible for some indoor units to operate in heating mode and another part of indoor units to operate in cooling mode, and it is difficult to meet the room temperature adjustment needs of different users.

Further, the existing multi-line air-conditioning system includes a three-pipe valve box type multi-line central air conditioner, which can make indoor units of the same valve box refrigerant circuit operate in the same working mode by switching the refrigerant circuit. The indoor units with different valve box refrigerant circuits can be operated in different working modes. However, the disadvantage of the multi-line central air conditioner is that the overall flexibility of the multiple indoor units depends entirely on the number of valve boxes. If the number of valve boxes is configured too much, the complexity of the piping system of the multi-line central air conditioner will increase. If the number of valve boxes is configured too small and it is difficult for most indoor units to freely choose the working mode, the complexity of the pipeline system and the overall operational flexibility of multiple indoor units are difficult to coordinate.

Correspondingly, a new multi-line air conditioning system is needed in the art to solve the above-mentioned problems.

Summary of the invention

In order to solve the above-mentioned problems in the prior art, that is, in order to solve the problem that the existing multi-line central air conditioner is difficult to realize the flexible operation of multiple indoor units in different working modes while ensuring the simplicity of the pipeline system, the present invention provides a A multi-line air-conditioning system, the multi-line air-conditioning system includes a first heat exchange coil, a second heat exchange coil, and a plurality of indoor units, and flows in the first heat exchange coil and the second heat exchange coil For refrigerants with different temperatures, the indoor unit includes a heat exchanger, and the heat exchanger is connected to the first heat exchange coil through a first refrigerant input pipe and a first refrigerant output pipe, so that the first heat exchange The refrigerant in the heat coil can flow into the heat exchanger through the first refrigerant input pipe, and the refrigerant in the heat exchanger can flow into the first heat exchange plate through the first refrigerant output pipe In the pipe, a first valve member is provided on the first refrigerant input pipe, and the first valve member is configured to be able to adjust the refrigerant flow rate in the first refrigerant input pipe, and the heat exchanger also passes through the second refrigerant The input pipe and the second refrigerant output pipe are connected to the second heat exchange coil, so that the refrigerant in the second heat exchange coil can flow into the heat exchanger through the second refrigerant input pipe, and The refrigerant in the heat exchanger can flow into the second heat exchange coil through the second refrigerant output pipe, and the second refrigerant input pipe is provided with a second valve member, and the second valve member It is configured to be able to adjust the flow rate of the refrigerant in the second refrigerant input pipe.

In the preferred technical solution of the above multi-line air conditioning system, the heat exchanger includes a refrigerant mixing pipe, the first refrigerant input pipe and the second refrigerant input pipe are in communication with the input end of the refrigerant mixing pipe, and the The first refrigerant output pipe and the second refrigerant output pipe communicate with the output end of the refrigerant mixing pipe.

In the preferred technical solution of the above multi-line air conditioning system, a third valve member is provided on the first refrigerant output pipe, and the third valve member is configured to be able to adjust the refrigerant flow rate in the first refrigerant output pipe, so The second refrigerant output pipe is provided with a fourth valve member, and the fourth valve member is configured to be able to adjust the refrigerant flow rate in the second refrigerant output pipe.

In the preferred technical solution of the above multi-line air conditioning system, the third valve member and/or the fourth valve member are electronic expansion valves.

In the preferred technical solution of the above multi-line air conditioning system, the heat exchanger includes a first heat exchange tube and a second heat exchange tube, and the input end of the first heat exchange tube is connected to the first refrigerant input tube, The output end of the first heat exchange tube is connected to the first refrigerant output tube, the input end of the second heat exchange tube is connected to the second refrigerant input tube, and the output end of the second heat exchange tube Connected with the second refrigerant output pipe.

In the preferred technical solution of the above-mentioned multi-line air conditioning system, the first heat exchange tubes and the second heat exchange tubes are arranged in a staggered manner.

In the preferred technical solution of the above-mentioned multi-line air conditioning system, the indoor unit further includes a blower, and the blower is arranged near the heat exchanger.

In the preferred technical solution of the above multi-line air conditioning system, the first valve member and/or the second valve member are electronic expansion valves.

In the preferred technical solution of the above multi-line air conditioning system, the first heat exchange coil and the second heat exchange coil belong to the same refrigerant circulation unit.

In the preferred technical solution of the above-mentioned multi-line air conditioning system, the first heat exchange coil and the second heat exchange coil belong to two refrigerant circulation units respectively.

Those skilled in the art can understand that the heat exchanger of each indoor unit of the multi-line air conditioning system of the present invention allows refrigerants of different temperatures in the first heat exchange coil and the second heat exchange coil to flow in at the same time. In this case, by controlling the ratio of refrigerant flow between the first heat exchange coil and the second heat exchange coil, the heat exchangers of each indoor unit can emit different expected heat or cold, so that different heat exchangers With different heat exchange capabilities and realizing the free choice of the working mode of any indoor unit, the multi-line air-conditioning system of the present invention has multiple working modes (cooling/heating/partial cooling, partial heating) without adding complexity In the case of refrigerant switching pipelines, the diversity of the overall operation of the multi-connected air conditioning system is improved.

Preferably, the above-mentioned heat exchanger includes a refrigerant mixing tube that allows refrigerants of different temperatures in the first heat exchange coil and the second heat exchange coil to be mixed and flowed, so as to control the mixing ratio of the cold and hot refrigerants. The heat/cold transfer capacity of the heater.

Alternatively, the above heat exchanger includes a first heat exchange tube and a second heat exchange tube. The first heat exchange tube allows the refrigerant in the first heat exchange coil to flow in, and the second heat exchange tube allows the refrigerant in the second heat exchange coil to flow in. The refrigerant flows in to adjust the heat/cold capacity transfer capacity of the heat exchanger as a whole by adjusting the respective refrigerant flow rates in the two heat exchange tubes.

Description of the drawings

The preferred embodiments of the present invention will be described below with reference to the drawings. The attached picture is:

FIG. 1 is a schematic diagram of the overall structure of the first embodiment of the multi-connected air conditioning system of the present invention;

2 is a schematic diagram of the overall structure of the second embodiment of the multi-connected air conditioning system of the present invention.

Reference signs: 1. first heat exchange part; 101, first heat exchange coil; 102, evaporator; 103, first compressor; 2. second heat exchange part; 201, second heat exchange coil; 202. Condenser; 203. Second compressor; 3. Indoor unit; 4. Air blower; 5. First refrigerant input pipe; 6. First refrigerant output pipe; 7. First valve; 8. Second Refrigerant input pipe; 9. Second refrigerant output pipe; 10. Second valve; 11. Three-way joint; 12. Third compressor.

detailed description

First of all, those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention, and are not intended to limit the protection scope of the present invention. Those skilled in the art can adjust it accordingly as needed to adapt to specific applications. In addition, it should be noted that in the description of the present invention, the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

In addition, it should also be noted that in the description of the present invention, unless otherwise clearly defined and defined, the terms "connected", "connected", and "connected" should be understood in a broad sense. For example, they can be fixed or fixed. It is a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those skilled in the art, the specific meaning of the above-mentioned terms in the present invention can be understood according to specific circumstances.

As shown in Figure 1 or Figure 2, the multi-line system of the present invention includes a first heat exchange coil 101, a second heat exchange coil 201 and a plurality of indoor units 3, wherein the first heat exchange coil 101 and the second heat exchange coil Refrigerants with different temperatures flow in the heat exchange coil 201, and the indoor unit 3 includes a heat exchanger (located inside the indoor unit 3, not shown in the figure) and a blower 4. The blower 4 is arranged near the heat exchanger to promote the flow of the hot air or cold air after the heat exchange with the heat exchanger into the room. The heat exchanger is connected to the first heat exchange coil 101 through the first refrigerant input pipe 5 and the first refrigerant output pipe 6, so that the refrigerant in the first heat exchange coil 101 can flow into the heat exchange through the first refrigerant input pipe 5 The refrigerant in the heat exchanger can flow into the first heat exchange coil 101 through the first refrigerant output pipe 6. A first valve member 7 is provided on the first refrigerant input pipe 5, and the first valve member 7 is configured to be able to adjust the refrigerant flow rate in the first refrigerant input pipe 5. The heat exchanger is also connected to the second heat exchange coil 201 through the second refrigerant input pipe 8 and the second refrigerant output pipe 9, so that the refrigerant in the second heat exchange coil 201 can flow into and exchange through the second refrigerant input pipe 8. In the heat exchanger, the refrigerant in the heat exchanger can flow into the second heat exchange coil 201 through the second refrigerant output pipe 9. A second valve member 10 is provided on the second refrigerant input pipe 8, and the second valve member 10 is configured to be able to adjust the refrigerant flow rate in the second refrigerant input pipe 8. In other words, the first refrigerant input pipe 5 and the first refrigerant output pipe 6 can constitute one refrigerant circuit, and the second refrigerant input pipe 8 and the second refrigerant output pipe 9 can constitute another refrigerant circuit. The heat exchanger is connected to the two refrigerant circuits at the same time, so that the refrigerant flowing out of the first heat exchange coil 101 and the refrigerant flowing out of the second heat exchange coil 201 can respectively flow through the heat exchanger through the corresponding refrigerant circuit. It flows into the first heat exchange coil 101 and the second heat exchange coil 201. In this case, when the temperature of the refrigerant in the first heat exchange coil 101 and the second heat exchange coil 201 are different, the first valve member 7 and the second valve member 10 are used to control the temperature of the refrigerant in the first heat exchange coil 101, respectively. The flow rate of the outgoing refrigerant and the flow rate of the refrigerant out of the second heat exchange coil 201 can adjust the ratio of the amount of refrigerant at two different temperatures flowing through the heat exchanger at the same time, and then set the ratio according to the heat exchange requirements of each heat exchanger. In the case of refrigerant volume ratio, each heat exchanger can flow through the refrigerant at a set temperature, so that each heat exchanger has its own expected heat/cold capacity transfer capacity, so that each indoor unit 3 can be adjusted according to its own Set the ratio of the refrigerant flowing through the heat exchangers of the indoor unit 3 to achieve independent heating or cooling of each indoor unit 3.

In the above embodiment of the multi-connected air-conditioning system, the multi-connected air-conditioning system includes an outdoor part and an indoor part, wherein the outdoor part is divided into two parts including the first heat exchange coil 101 and the second heat exchange coil 201 A small part, the indoor part includes a plurality of indoor units 3. One of the two small parts of the heat exchange coil can flow a refrigerant with a constant temperature and a higher temperature, and the other can flow a refrigerant with a constant and lower temperature (hereinafter, the two temperature refrigerants are referred to as high-temperature refrigerant and low-temperature refrigerant) . For an indoor unit 3 alone, the two refrigerant circuits composed of the first refrigerant input pipe 5 and the first refrigerant output pipe 6, as well as the second refrigerant input pipe 8 and the second refrigerant output pipe 9 respectively, enable the first heat exchange plate The high-temperature refrigerant and the low-temperature refrigerant in the tube 101 and the second heat exchange coil 201 simultaneously flow through the heat exchanger at a set flow rate (the set flow rate can be adjusted by the first valve member 7 and the second valve member 10). When each heat exchanger is installed in a multi-line air-conditioning system using a dual refrigerant circuit pipeline connection, the heat exchangers of multiple indoor units 3 are connected in parallel to the part containing the first heat exchange coil 101 at the same time And the part containing the second heat exchange coil 201. In the case that the first heat exchange coil 101 and the second heat exchange coil 201 continuously flow out high temperature refrigerant and low temperature refrigerant at a constant temperature, the high temperature refrigerant and the low temperature refrigerant can be simultaneously delivered to each heat exchanger through two refrigerant circuits . By adjusting the opening of the valve on each refrigerant circuit, the overall temperature of the high and low temperature refrigerant flowing through the heat exchanger can be changed, so that each heat exchanger can release the expected heat or cold energy and reduce the heat Or cold energy is transferred to the airflow, and then forms a hot or cold airflow of different temperatures that meets the room temperature adjustment needs of each user, which realizes the independent control of each indoor unit 3, so that any indoor unit 3 can freely choose the operating cooling mode Or heating mode to meet the temperature control needs of different users. There is no need to set up complicated refrigerant switching pipelines for multiple indoor units 3, so that the pipeline structure is simple and easy to arrange, the refrigerant flow control is simpler, easy to implement, easy to install and maintain, and more practical.

Continuing to refer to FIG. 1, FIG. 1 shows an overall structure of the first embodiment of the multi-line air conditioning system of the present invention. In the first embodiment of the present invention, the first heat exchange coil 101 and the second heat exchange coil 201 belong to two refrigerant circulation units respectively, that is, the part containing the first heat exchange coil 101 itself can constitute a complete The refrigerant circulation unit realizes the closed circulation of the refrigerant. The part containing the second heat exchange coil 201 itself can constitute another complete refrigerant circulation unit and realize the closed circulation of the refrigerant. Each indoor unit 3 is connected to the refrigerant circulation unit including the first heat exchange coil 101 through a refrigerant circuit, and is connected to the refrigerant circulation unit including the second heat exchange coil 201 through another refrigerant circuit. A plurality of indoor units 3 are connected in parallel to two refrigerant circulation units through this connection method. Specifically, Figure 1 shows the first heat exchange part 1 (that is, one of the refrigerant circulating units), the second heat exchange part 2 (that is, the other of the refrigerant circulating units), multiple indoor units 3, and refrigerant pipelines. , All the arrows in the figure indicate the flow direction of the refrigerant. Taking the first heat exchange coil 101 as the high temperature refrigerant, the first heat exchange coil 101 as the condenser 202, the second heat exchange coil 201 as the low temperature refrigerant, and the second heat exchange coil 201 as the evaporator 102 As an example, the first heat exchange part 1 includes a first heat exchange coil 101, an evaporator 102, a first compressor 103, and a throttling device (not shown in the figure) (the first heat exchange part 1 in FIG. 1 The second heat exchange part 2 only shows the components of the heat exchange coil, evaporator, condenser, compressor, refrigerant flow pipeline, etc., but does not show the specific connection relationship between the components. The first change in the figure The distribution and connection diagrams of the components of the hot part 1 and the second heat exchange part 2 do not represent the actual installation positions and pipeline connections of the components of the first heat exchange part 1 and the second heat exchange part 2. Fig. 2 is the same as Fig. 1) , The first heat exchange coil 101, the evaporator 102, the first compressor 103 and the throttling device are connected to form a closed refrigerant circulation circuit through the refrigerant flow pipeline. The second heat exchange section 2 includes a second heat exchange coil 201, a condenser 202, a second compressor 203, and a throttling device (not shown in the figure). The second heat exchange coil 201, a condenser 202, and a second The compressor 203 and the throttling device are connected to form another closed refrigerant circulation circuit through the refrigerant flow pipeline. In view of the above-mentioned pipeline connection method of the refrigerant circulation circuit and the construction method of the refrigerant circulation circuit of a conventional air conditioner, the specific pipeline connection scheme of the first heat exchange part 1 and the second heat exchange part 2 will not be described in detail here. The two ends of the first refrigerant input pipe 5 are respectively connected to the refrigerant input end of the heat exchanger and the refrigerant output end of the first heat exchange coil 101, and the two ends of the first refrigerant output pipe 6 are respectively connected to the refrigerant output of the heat exchanger End and the refrigerant input end of the first heat exchange coil 101. The first valve 7 is arranged on the first refrigerant input pipe 5 between the refrigerant input end of the heat exchanger and the refrigerant output end of the first heat exchange coil 101 to control the flow of the high temperature refrigerant flowing into the heat exchanger . Two ends of the second refrigerant input pipe 8 are respectively connected to the refrigerant input end of the heat exchanger and the refrigerant output end of the first heat exchange coil 101, and both ends of the second refrigerant output pipe 9 are respectively connected to the refrigerant output of the heat exchanger End and the refrigerant input end of the first heat exchange coil 101. The second valve 10 is arranged on the second refrigerant input pipe 8 between the refrigerant input end of the heat exchanger and the refrigerant output end of the second heat exchange coil 201, so as to control the flow of low temperature refrigerant flowing into the heat exchanger .

Further, the above-mentioned heat exchanger includes a refrigerant mixing tube. The refrigerant output ends of the first refrigerant input pipe 5 and the second refrigerant input pipe 8 are both connected with the input end of the refrigerant mixing pipe, and the refrigerant input ends of the first refrigerant output pipe 6 and the second refrigerant output pipe 9 are both connected with the refrigerant mixing pipe The output ends of the first heat exchange coil 101 are connected, and the low temperature refrigerant in the second heat exchange coil 201 can flow into the heat exchanger through the first refrigerant input pipe 5 and the second refrigerant input pipe 8 respectively. , And mixed into the refrigerant of the expected temperature in the refrigerant mixing tube of the heat exchanger, and then diverted to the first refrigerant output pipe 6 and the second refrigerant output pipe 9, passing through the first refrigerant output pipe 6 and the second refrigerant output pipe 9 It flows into the first heat exchange coil 101 and the second heat exchange coil 201 respectively. In this case, for any indoor unit 3, when the high-temperature refrigerant in the first heat exchange coil 101 and the low-temperature refrigerant in the second heat exchange coil 201 flow into the indoor unit 3 at a certain flow rate, the refrigerant mixes When inside the tube, the refrigerants of two temperatures will be mixed into the refrigerant of the expected temperature, so that the heat exchanger can release the expected heat and cold, and realize the heat exchange with the airflow.

Furthermore, as shown in FIG. 1, the multi-line air conditioning system of the present invention further includes a plurality of three-way joints 11. The three-way joint 11 includes a refrigerant output terminal and two refrigerant input terminals. The refrigerant output end of the first refrigerant input pipe 5 is connected to one refrigerant input end of the three-way joint 11, and the refrigerant output end of the second refrigerant input pipe 8 is connected to the other refrigerant input end of the three-way joint 11. The refrigerant output end is in communication with the refrigerant input section of the refrigerant mixing pipe, so as to realize the combined connection of the first refrigerant input pipe 5 and the second refrigerant input pipe 8 with the refrigerant mixing pipe. Of course, the above implementation is only a preferred example of the present invention. In the actual pipeline connection scheme, the designer can choose any one that can realize the combined connection of the first refrigerant input pipe 5 and the second refrigerant input pipe 8 with the refrigerant mixing pipe. For example, the refrigerant output ends of the first refrigerant input pipe 5 and the second refrigerant input pipe 8 are integrated, and the first refrigerant input pipe 5 and the second refrigerant input pipe 8 share a refrigerant output port.

In this case, preferably, a third valve member (not shown in the figure) is provided on the first refrigerant output pipe 6, and the third valve member is configured to be able to adjust the refrigerant flow rate in the first refrigerant output pipe 6. A fourth valve member is provided on the second refrigerant output pipe 9, and the fourth valve member is configured to be able to adjust the refrigerant flow rate in the second refrigerant output pipe 9. Through the above arrangement, the refrigerant inside the heat exchanger can flow into the first heat exchange coil 101 and the second heat exchange coil at a set flow rate when flowing through the first refrigerant output pipe 6 and the second refrigerant output pipe 9, respectively. 201. Avoid the situation that the refrigerant of the refrigerant circulation unit to which the first heat exchange coil 101 belongs or the refrigerant circulation unit to which the second heat exchange coil 201 belongs is significantly reduced during the circulation process, which facilitates the refrigerant flow pipelines of the two refrigerant circulation units The internal pressure remains stable.

As an alternative embodiment, the heat exchanger includes a first heat exchange tube and a second heat exchange tube, the refrigerant input end of the first heat exchange tube is connected to the first refrigerant input tube 5, and the refrigerant of the first heat exchange tube The output end is connected with the first refrigerant output tube 6 so that the high-temperature refrigerant in the first heat exchange tube can flow through the first heat exchange tube. The refrigerant input end of the second heat exchange tube is connected to the second refrigerant input tube 8, and the refrigerant output end of the second heat exchange tube is connected to the second refrigerant output tube 9 so that the low temperature refrigerant in the second heat exchange tube can flow through the first 2. Heat exchange tube. By making the high temperature refrigerant and the low temperature refrigerant flow through the first heat exchange tube and the second heat exchange tube of the heat exchanger at the same time, the heat released by the first heat exchange tube and the cold energy released by the second heat exchange tube can be integrated into The expected heat/cold capacity, so that the airflow can exchange heat with the heat exchanger that emits the expected heat/cold capacity, and become a hot airflow or a cold airflow at a set temperature. In this embodiment, since the refrigerants of the two refrigerant circulation units always circulate independently and are not mixed and converge, the refrigerants in the two refrigerant circulation units may be the same type of refrigerant or different types of refrigerants.

Further, the first heat exchange tube and the second heat exchange tube are arranged in a staggered manner to avoid uneven distribution of the heat/cold amount emitted by the heat exchanger. Wherein, the specific manner of the above-mentioned staggered arrangement is not limited, and the specific staggered form can be set according to pipeline arrangement requirements, specific heat exchange requirements, etc. For example, the first heat exchange tube and the second heat exchange tube can be wound around each other, or the first heat exchange tube and the second heat exchange tube respectively include a multi-layer connected and curved and coiled surface structure. The surface structure and the surface structure of the second heat exchange tube are arranged to cross each other.

In the above multiple embodiments, any one or more (two or more) of the first valve element 7, the second valve element 10, the third valve element, and the fourth valve element are electronic expansion valves. By adjusting the opening degree of the electronic expansion valve, the refrigerant flow of the pipe where the corresponding valve is located can be adjusted. Of course, the above-mentioned valve member may also be a valve capable of adjusting the flow of refrigerant besides the electronic expansion valve. The above-mentioned four valve parts may be the same type of flow control valve, or may include multiple flow control valves.

Continuing to refer to FIG. 2, FIG. 2 shows an overall structure of the second embodiment of the multi-line air conditioning system of the present invention. In the second embodiment of the present invention, the first heat exchange coil 101 and the second heat exchange coil 201 belong to the same refrigerant circulation unit, that is, the part containing the first heat exchange coil 101 and the second heat exchange coil The parts of the coil 201 together constitute a complete refrigerant circulation unit, which realizes the closed circulation of the refrigerant. Each indoor unit 3 is connected to the refrigerant circulation unit through two refrigerant circuits. A plurality of indoor units 3 are connected in parallel to the refrigerant circulation unit through this connection method. Specifically, FIG. 2 shows the first heat exchange coil 101, the second heat exchange coil 201, the third compressor 12, a plurality of indoor units 3, and refrigerant flow pipelines. All arrows in the figure indicate The flow direction of the refrigerant. Taking the first heat exchange coil 101 as the high temperature refrigerant, the first heat exchange coil 101 as the condenser 202, the second heat exchange coil 201 as the low temperature refrigerant, and the second heat exchange coil 201 as the evaporator 102 As an example, the first heat exchange coil 101, the second heat exchange coil 201, the third compressor 12, and the throttling device (not shown in the figure) are connected to form a closed refrigerant circulation circuit through a refrigerant flow pipeline. The pipeline connection method of the refrigerant circulation circuit is the same as the pipeline construction method of the refrigerant circulation circuit of a conventional air conditioner. The two ends of the first refrigerant input pipe 5 are respectively connected to the refrigerant input end of the heat exchanger and the refrigerant output end of the first heat exchange coil 101, and the two ends of the second refrigerant output pipe 9 are respectively connected to the refrigerant output of the heat exchanger And the refrigerant output end of the first heat exchange coil 101 so that the refrigerant in the refrigerant output pipe of the first heat exchange coil 101 can flow into the refrigerant output pipe after flowing through the heat exchanger. The first valve 7 is arranged on the first refrigerant input pipe 5, between the refrigerant input end of the heat exchanger and the refrigerant output end of the first heat exchange coil 101, so as to control the flow of the high temperature refrigerant flowing into the heat exchanger . Two ends of the second refrigerant input pipe 8 are respectively connected to the refrigerant input end of the heat exchanger and the refrigerant output end of the second heat exchange coil 201, and both ends of the second refrigerant output pipe 9 are respectively connected to the refrigerant output of the heat exchanger And the refrigerant input end of the second heat exchange coil 201, so that the refrigerant in the refrigerant output pipe of the second heat exchange coil 201 can flow into the refrigerant output pipe after flowing through the heat exchanger. The second valve 10 is arranged on the second refrigerant input pipe 8 between the refrigerant input end of the heat exchanger and the refrigerant output end of the second heat exchange coil 201, so as to control the flow of low temperature refrigerant flowing into the heat exchanger .

Further, the above heat exchanger can be configured to allow mixed flow of high-temperature refrigerant and low-temperature refrigerant, such as a refrigerant mixing tube, or a structure that allows high-temperature refrigerant and low-temperature refrigerant to flow independently in parallel, such as a first heat exchange tube. And the second heat exchange tube. Among them, the specific pipe connection mode of the refrigerant mixing tube or the first heat exchange tube and the second heat exchange tube has been described in the foregoing, so it will not be repeated here.

In the first embodiment and the second embodiment of the present invention, both the first heat exchange coil 101 and the second heat exchange coil 201 can output a refrigerant with a constant temperature. In actual implementation, the standard for constant temperature may specifically be that the fluctuation value of the temperature of the refrigerant does not exceed the set difference. For example, when the setting difference is 1 degree, the high temperature refrigerant is set to 50 degrees, and the low temperature refrigerant is 20 degrees, the temperature of the high temperature refrigerant can be maintained at any temperature in the range of 49 degrees to 51 degrees, and the temperature of the low temperature refrigerant is maintained Any temperature within the range of 19 degrees to 21 degrees is fine. Wherein, the above-mentioned setting difference can be set according to the expected operating stability of the multi-connected air-conditioning system.

Although the multiple embodiments described in the present invention are described in conjunction with the situation where each indoor unit 3 is independently controlled, this is only a preferred embodiment of the present invention and should not constitute a limitation to the protection of the present invention. Without deviating from the basic principle of the present invention, those skilled in the art can adjust the overall pipeline setting plan of the indoor unit 3 according to actual control requirements. For example, some indoor units 3 of the multiple indoor units 3 may not When independent operation control is required, this part of the indoor unit 3 can also be connected in parallel to the same first refrigerant input pipe 5 and the same second refrigerant input pipe 8 and the same first refrigerant output pipe 6 and the same second refrigerant output pipe 9 Therefore, the entire (mixed) temperature of the refrigerant flowing through the heat exchanger of the partial indoor unit 3 is the same. Or, when the number of the part of the indoor unit 3 is small, the part of the indoor unit 3 may also be connected in series to the same first refrigerant input pipe 5 and the same second refrigerant input pipe 8 and the same first refrigerant output pipe 6 And the same second refrigerant output pipe 9. The technical solution adjusted in this way does not deviate from the basic principle of the present invention, and therefore will fall within the protection scope of the present invention.

In summary, the heat exchanger of each indoor unit 3 of the multi-unit air conditioning system of the present invention allows the high-temperature refrigerant in the first heat exchange coil 101 and the low-temperature refrigerant in the second heat exchange coil 201 to flow in at the same time. In this case, by controlling the refrigerant flow ratio of the first heat exchange coil 101 and the second heat exchange coil 201, the heat exchangers of each indoor unit 3 can emit different expected heat or cold, so as to make different The heat exchanger has different heat exchange capabilities and realizes the free choice of the working mode of any indoor unit 3, so that the multi-line air-conditioning system of the present invention has multiple working modes (cooling/heating/partial cooling, partial heating), Without adding multiple complicated refrigerant switching pipelines, the diversity of the overall operation of the multi-connected air conditioning system is improved.

So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

A multi-line air-conditioning system, characterized in that, the multi-line air-conditioning system includes a first heat exchange coil, a second heat exchange coil and a plurality of indoor units, the first heat exchange coil and the second heat exchange coil There are refrigerants of different temperatures flowing in the heat exchange coil, and the indoor unit includes a heat exchanger,

The heat exchanger is connected to the first heat exchange coil through a first refrigerant input pipe and a first refrigerant output pipe, so that the refrigerant in the first heat exchange coil can pass through the first refrigerant input pipe Flows into the heat exchanger, and enables the refrigerant in the heat exchanger to flow into the first heat exchange coil through the first refrigerant output pipe, and the first refrigerant input pipe is provided with a first A valve member, the first valve member is configured to be able to adjust the flow rate of the refrigerant in the first refrigerant input pipe,

The heat exchanger is also connected to the second heat exchange coil through a second refrigerant input pipe and a second refrigerant output pipe, so that the refrigerant in the second heat exchange coil can be input through the second refrigerant The tube flows into the heat exchanger, and enables the refrigerant in the heat exchanger to flow into the second heat exchange coil through the second refrigerant output pipe, and the second refrigerant input pipe is provided with a first Two valve parts, the second valve part is arranged to be able to adjust the refrigerant flow in the second refrigerant input pipe.
The multi-line air conditioning system according to claim 1, wherein the heat exchanger comprises a refrigerant mixing tube,

The first refrigerant input pipe and the second refrigerant input pipe communicate with the input end of the refrigerant mixing pipe, and the first refrigerant output pipe and the second refrigerant output pipe are connected to the output end of the refrigerant mixing pipe. Connected.
The multi-line air-conditioning system according to claim 2, wherein a third valve member is provided on the first refrigerant output pipe, and the third valve member is configured to be able to adjust the pressure in the first refrigerant output pipe. Refrigerant flow rate,

A fourth valve member is provided on the second refrigerant output pipe, and the fourth valve member is configured to be able to adjust the refrigerant flow rate in the second refrigerant output pipe.
The multi-line air conditioning system according to claim 3, wherein the third valve member and/or the fourth valve member are electronic expansion valves.
The multi-line air conditioning system according to claim 1, wherein the heat exchanger comprises a first heat exchange tube and a second heat exchange tube,

The input end of the first heat exchange tube is connected to the first refrigerant input pipe, and the output end of the first heat exchange tube is connected to the first refrigerant output pipe,

The input end of the second heat exchange tube is connected with the second refrigerant input pipe, and the output end of the second heat exchange tube is connected with the second refrigerant output pipe.
The multi-line air conditioning system according to claim 4, wherein the first heat exchange tube and the second heat exchange tube are arranged in a staggered manner.
The multi-line air conditioning system according to claim 1, wherein the indoor unit further comprises a blower, and the blower is arranged near the heat exchanger.
The multi-line air conditioning system according to claim 1, wherein the first valve member and/or the second valve member are electronic expansion valves.
The multi-line air conditioning system according to any one of claims 1 to 8, wherein the first heat exchange coil and the second heat exchange coil belong to the same refrigerant circulation unit.
The multi-line air conditioning system according to any one of claims 1 to 8, wherein the first heat exchange coil and the second heat exchange coil belong to two refrigerant circulation units respectively.