Heating, ventilation and air conditioning system

Abstract

A heating, ventilation and air conditioning system, which conveys, by means of pressure relief lines (800) in communication with a heat source-side line (500) and indoor-side lines (400), a refrigerant leaked into indoor units (100) to the heat source-side line (500). Thus, when a refrigerant shut-off valve (600) of any indoor unit (100) is closed, a pressure relief valve (900) corresponding to said indoor unit (100) can be opened by means of the pressure relief line (800) corresponding to the indoor unit (100), and the refrigerant leaked into the indoor unit (100) and the corresponding indoor-side line (400) is discharged to the heat source-side line (500), thereby preventing pipe burst caused by refrigerant accumulation in the indoor unit (100) and the indoor-side line (400), and improving the operational safety of the heating, ventilation and air conditioning system.

Description

Heating ventilation system TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioning, in particular to a heating ventilation system. BACKGROUND

[0002] An air conditioner uses refrigerant to absorb heat to achieve the effect of refrigeration, or uses refrigerant to release heat to achieve the effect of heating. With the increasing awareness of environmental protection, flammable refrigerants are gradually used to replace refrigerants such as freon, carbon dioxide, and ammonia, which have high global warming potential (GWP) values.

[0003] Since flammable refrigerants (for example, R32 refrigerant, R290 refrigerant, and R454B refrigerant) are flammable, in order to ensure safety during use, a "cut-off" method is usually used to block the refrigerant from entering the leakage space. If the refrigerant is affected by external heat sources, the pressure will rise, and at the same time, due to being "cut off", it cannot release pressure, which can easily cause safety problems such as "pipe explosion". SUMMARY

[0004] The present application provides a heating ventilation system, which can transport the refrigerant leaked in the indoor side pipeline to the source heat pipeline through the pressure relief pipeline by opening the corresponding pressure relief valve of the indoor unit, thereby improving the safety of the heating ventilation system.

[0005] The present application provides a heating ventilation system, which comprises a heat source unit, a plurality of indoor units, a refrigerant cut-off valve, a heat source side pipeline connected with the heat source unit, an indoor side pipeline connected with each indoor unit, a plurality of pressure relief pipelines, a plurality of pressure relief valves, and a gas-liquid separator; wherein the heat source side pipeline is connected with the indoor side pipeline through the refrigerant cut-off valve; the heat source side pipeline comprises a first pipeline, a second pipeline, a gas pipeline, and a liquid pipeline; the refrigerant cut-off valve comprises a first refrigerant cut-off valve and a second refrigerant cut-off valve; the gas-liquid separator is connected with the second pipeline to separate the refrigerant of the second pipeline into liquid refrigerant and gaseous refrigerant; the gaseous refrigerant is transported to the indoor side pipeline through the gas pipeline, and the liquid refrigerant is sent to the indoor side pipeline through the liquid pipeline; the first refrigerant cut-off valve is connected with the liquid pipeline, and the second refrigerant cut-off valve is connected with the gas pipeline and the indoor gas pipe formed by the first pipeline; one end of the pressure relief pipeline is communicated with the heat source side pipeline, and the other end of the pressure relief pipeline is communicated with the indoor side pipeline; the pressure relief valve is arranged on the pressure relief pipeline; when the first refrigerant cut-off valve and the second refrigerant cut-off valve are closed and the pressure of the indoor side pipeline is greater than a safety threshold, the pressure relief valve is opened, and the refrigerant of the indoor side pipeline is released into the heat source side pipeline through the pressure relief pipeline.

[0006] In the embodiment of the present application, the leaked refrigerant in the indoor unit is transported to the heat source side pipeline through the pressure relief pipeline in communication with the heat source side pipeline and the indoor side pipeline, so that when the refrigerant cut valve of any indoor unit is closed, the refrigerant leaked in the indoor unit and the indoor side pipeline is discharged to the heat source side pipeline through the opening of the pressure relief valve corresponding to the indoor unit and the pressure relief pipeline, avoiding the pipe burst phenomenon caused by the accumulation of refrigerant in the indoor unit and the indoor side pipeline, and improving the safety of the heating system. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0008] Fig. 1 is a structure schematic diagram of a heating system provided by the embodiment of the present application;

[0009] Fig. 2 is a structure schematic diagram of a heating system provided by the embodiment of the present application;

[0010] Fig. 3 is a structure schematic diagram of a heating system provided by the embodiment of the present application;

[0011] Fig. 4 is a structure schematic diagram of a heating system provided by the embodiment of the present application.

[0012] Label explanation:

[0013] Embodiment of the present application

[0014] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0015] In the description of the present application, it should be understood that the terms "first", "second" and the like are used only for descriptive purposes, and are not intended to indicate or imply relative importance. In the description of the present application, it should be noted that, unless otherwise specified and limited, "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or optionally also includes other steps or units inherent to the process, method, product or device. The specific meaning of the above terms in the present application can be understood by the person skilled in the art. In addition, in the description of the present application, "a plurality of" means two or more, unless otherwise specified. The association relationship of the associated objects is described, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0016] The embodiment of the present application proposes a heating and ventilation system, which refers to a system for realizing heating, ventilation and air conditioning in a building, mainly including a compressor, an indoor unit and the like, which mainly realizes heat transfer and temperature regulation through phase change of refrigerant. With the enhancement of global environmental protection consciousness, reducing greenhouse gas emissions has become an important task. Therefore, traditional high global warming potential (Global Warming Potential, GWP) refrigerants, such as R410A and the like, are gradually banned or limited in use, and refrigerants with lower GWP value are used instead, including some flammable refrigerants such as R32, R454B and R290.

[0017] However, the flammability of these alternative refrigerants brings new safety challenges to the design and operation of the heating and ventilation system. In order to cope with these challenges, the regulations and standards of each region have put forward strict requirements and restrictions on the use of flammable refrigerants. For example, the "cut-off" method is used to block the diffusion of refrigerant in the event of leakage, in order to reduce the potential risk of fire and explosion. However, if the refrigerant in the system is affected by external heat sources to cause pressure rise, and cannot release pressure in time due to being "cut off", it may cause safety problems such as "pipe burst".

[0018] In order to solve the above problems, please refer to Figure 1, which is a structural schematic diagram of the heating and ventilation system of the present application.

[0019] As shown in Figure 1, in the embodiment of the present application, the heating and ventilation system includes a heat source unit and a plurality of indoor units 100, a refrigerant cutoff valve 600, a heat source side pipeline 500, an indoor side pipeline 400, a pressure relief pipeline 800, a pressure relief valve 900, and a gas-liquid separator 1200.

[0020] In FIG. 1, the heat source side pipe 500 is connected to the indoor side pipe 400 through the refrigerant cut valve 600, the heat source side pipe 500 is connected to the heat source unit 1100, and the indoor side pipe 400 is connected to each indoor unit 100, respectively.

[0021] The heat source side pipe 500 includes the first pipe 200, the second pipe 300, the liquid pipe 301, and the gas pipe 302. The first pipe 200 is connected to the refrigerant recovery pipe of the heat source unit 1000, the second pipe 300 is connected to the refrigerant output pipe of the heat source unit, the inlet of the gas-liquid separator 1200 is connected to the second pipe 300, the first outlet of the gas-liquid separator 1200 is connected to the liquid pipe 301, and the second passage of the gas-liquid separator 1200 is connected to the gas pipe 302.

[0022] The second pipe 300 has three cases for the refrigerant input into the gas-liquid separator 1200.

[0023] In the first case, the refrigerant input into the second pipe is liquid refrigerant, which is low-temperature refrigerant condensed by the heat source unit. The liquid refrigerant is transported from the first outlet of the gas-liquid separator to the liquid pipe 301.

[0024] In the second case, the refrigerant input into the second pipe is gaseous refrigerant, which is high-temperature gaseous refrigerant discharged from the exhaust port of the compressor of the heat source unit. The gaseous refrigerant is transported from the second outlet of the gas-liquid separator to the gas pipe 302.

[0025] In the third case, the refrigerant input into the second pipe is mixed refrigerant of gas and liquid phases. The liquid refrigerant is separated from the gaseous refrigerant by the gas-liquid separator, the liquid refrigerant is transported from the first outlet of the gas-liquid separator to the liquid pipe 301, and the gaseous refrigerant is transported from the second outlet of the gas-liquid separator to the gas pipe 302.

[0026] Referring to FIGS. 1 and 2, the heat source side pipe 500 further includes a refrigeration liquid header 501, a heating liquid header 502, a high-pressure gas header 503, and a low-pressure gas header 504. The liquid pipes are connected to the refrigeration liquid header 501 and the heating liquid header 502, respectively, the gas pipe is connected to the high-pressure gas header 503, and the low-pressure gas header 504 is connected to the first pipe 200. The heating liquid header 502 or the heating liquid header is connected to the low-pressure gas header 504 through a return branch pipe, thereby being connected to the first pipe 200.

[0027] The refrigerant cut valve 600 includes a first refrigerant cut valve 601 and a second refrigerant cut valve 602. The first refrigerant cut valve 601 and the second refrigerant cut valve 602 are provided in multiple numbers. One first refrigerant cut valve 601 and one second refrigerant cut valve 602 are connected to the liquid side and the gas side of one indoor unit, respectively.

[0028] A first refrigerant cutoff valve 601 communicates with the refrigerant header 501 and the heating refrigerant header 502 through a liquid pipe unit, and a second refrigerant cutoff valve 602 communicates with the high-pressure gas header 503 and the low-pressure gas header 504 through a gas pipe unit.

[0029] The number of the liquid pipe units corresponds to the number of the first refrigerant cutoff valve 601, and the number of the gas pipe units corresponds to the number of the second refrigerant cutoff valve 602.

[0030] A liquid pipe unit is configured to have an indoor unit liquid pipe 130 and a first liquid branch pipe and a second liquid branch pipe branched from the indoor unit liquid pipe 130, wherein one end of the indoor unit liquid pipe 130 is connected to the liquid cutoff valve, and the other end is branched to form the first liquid branch pipe and the second liquid branch pipe, one end of the first liquid branch pipe away from the branching point is connected to the heating refrigerant header 502, and one end of the second liquid branch pipe away from the branching point is connected to the refrigerant header 501. Further, a first check valve is provided on the first liquid branch pipe, which allows the refrigerant to flow only from the indoor unit liquid pipe 130 side to the heating refrigerant header 502 side, and a second check valve is provided on the second liquid branch pipe, which allows the refrigerant to flow only from the refrigerant header 501 side to the indoor unit liquid pipe 130 side.

[0031] A gas pipe unit is configured to have an indoor unit gas pipe 303 and a first gas branch pipe and a second gas branch pipe branched from the indoor unit gas pipe 303, wherein one end of the indoor unit gas pipe 303 is connected to the gas cutoff valve, and the other end is branched to form the first gas branch pipe and the second gas branch pipe, one end of the first gas branch pipe away from the branching point is connected to the high-pressure gas header 503, and one end of the second gas branch pipe away from the branching point is connected to the low-pressure gas header 504. Further, a first switching valve 701 is provided on the first gas branch pipe, which has the functions of opening or closing and having an adjustable opening degree in the open state, so that it can switch between the open and closed states, and also adjust the opening degree in the open state to adjust the refrigerant flow through the first gas branch pipe, and a second switching valve 702 is provided on the second gas branch pipe, which has the functions of opening or closing and having an adjustable opening degree in the open state, so that it can switch between the open and closed states, and also adjust the opening degree in the open state to adjust the refrigerant flow through the second gas branch pipe.

[0032] Further, the liquid cutoff valve and the gas cutoff valve are configured as solenoid valves or electronic expansion valves, and the second switching valve 702 and the first switching valve 701 are configured as electronic expansion valves.

[0033] One end of the pressure relief pipe 800 communicates with the heat source side pipe 500, the other end of the pressure relief pipe 800 communicates with the indoor side pipe 400, and the pressure relief valve 900 is provided on the pressure relief pipe 800.

[0034] Optionally, in the embodiments of the present application, the pressure relief pipeline 800 should be made of corrosion-resistant, pressure-resistant, low-temperature-resistant materials, such as stainless steel, copper alloy or special alloy, etc. It can effectively resist the corrosion of refrigerant and withstand the pressure changes that may occur during transportation. The connection parts of the pressure relief pipeline 800 and the heat source side pipeline 500, the indoor side pipeline 400 should adopt reliable sealing design, such as welding, flange connection or threaded connection, etc., and be equipped with corresponding sealing elements (such as gaskets, sealing rings, etc.), to ensure that the refrigerant will not leak during transmission.

[0035] In the embodiments of the present application, when the control module of the heating and cooling system identifies an abnormal working condition, it controls the first refrigerant cutoff valve 601 and the second refrigerant cutoff valve 602 to close. One of the abnormal working conditions is that the indoor unit 100 leaks refrigerant, and the control module of the heating and cooling system controls the first refrigerant cutoff valve 601 and the second refrigerant cutoff valve 602 corresponding to the indoor unit 100 to close, and the closing sequence can be that either the first refrigerant cutoff valve or the second refrigerant cutoff valve is closed first, and then the other one is closed. Another of the abnormal working conditions is that the power supply of the heating and cooling system is interrupted, and the control module of the heating and cooling system controls all the first refrigerant cutoff valves 601 and the second refrigerant cutoff valves 602 to close, and the closing sequence of all the refrigerant cutoff valves is to close them in turn, first closing the first refrigerant cutoff valve 601 and the second refrigerant cutoff valve 602 of the first indoor unit, and then closing the first refrigerant cutoff valve 601 and the second refrigerant cutoff valve 602 of the second indoor unit in turn.

[0036] When the first refrigerant cutoff valve 601 and the second refrigerant cutoff valve 602 of an indoor unit are in a closed state, the indoor side pipeline corresponding to the indoor unit is in a liquid-sealed state. The refrigerant pressure in the liquid-sealed state may rise, causing the refrigerant pressure in the indoor side pipeline to be greater than the pressure resistance of the pipeline, thereby causing pipeline explosion. If the refrigerant is flammable refrigerant such as R454B, the flammable refrigerant sprayed when the pipeline explodes may cause safety accidents. Therefore, the present application uses a pressure relief pipeline, the two ends of the pressure relief pipeline are connected to the indoor side pipeline 400 and the heat source side pipeline 500 respectively, and when it is identified that the refrigerant pressure in the indoor side pipeline is greater than a safety threshold, the pressure relief valve 900 is opened to release the refrigerant leaked from each indoor side pipeline 400 into the heat source side pipeline 500 through the pressure relief pipeline 800. The heat source side pipeline is connected to the heat source unit or other normally operating indoor units. Therefore, the pressure relief pipeline 800 can release the refrigerant into the heat source side pipeline.

[0037] In the embodiment of the present application, the leaked refrigerant in the indoor unit is transported to the heat source side pipeline through the pressure relief pipeline in communication with the heat source side pipeline and the indoor side pipeline, so that when the refrigerant cut valve 600 of any indoor unit is closed, the refrigerant leaked in the indoor unit 100 and the indoor side pipeline 400 is discharged to the heat source side pipeline 500 through the opening of the corresponding pressure relief valve 900 and the pressure relief pipeline 800, avoiding the burst of the indoor unit 100 and the indoor side pipeline 400 due to the accumulation of the refrigerant, and improving the safety of the heating system.

[0038] Please refer to FIG. 2, in the embodiment of the present application, the pressure relief pipeline 800 includes a pressure relief main pipeline 802 and a pressure relief branch pipeline 801 corresponding to each indoor unit 100, each pressure relief branch pipeline 801 is in communication with the pressure relief main pipeline 802, the pressure relief valve 900 is installed on the pressure relief main pipeline 802 or the pressure relief branch pipeline 801, one end of the pressure relief main pipeline 802 is in communication with the heat source side pipeline 500, and the other end of the pressure relief main pipeline 802 is in communication with the indoor side pipeline 400 of each indoor unit 100 through each pressure relief branch pipeline 801.

[0039] Specifically, there are multiple indoor units 100, each indoor unit 100 corresponds to a pressure relief branch pipeline 801, and the pressure relief branch pipeline 801 can be connected to the indoor side pipeline 400 at any position of the indoor side pipeline 400 when communicating with the indoor unit 100, so that the refrigerant in the corresponding indoor unit 100 can be discharged to the pressure relief branch pipeline 801 through the indoor side pipeline 400. It can be understood that the pipeline of the indoor unit 100 is in communication with the indoor side pipeline 400, so the pressure relief branch pipeline 801 can also be connected to the pipeline of the indoor unit 100, so that the refrigerant leaked in the indoor unit 100 and the indoor side pipeline 400 can also be discharged to the pressure relief branch pipeline 801. Each pressure relief branch pipeline 801 is in communication at the pressure relief main pipeline 802, and the pressure relief valve 900 is installed near the connection between the pressure relief main pipeline 802 and the heat source side pipeline 500, so that the leaked refrigerant can be discharged from the pipeline of the indoor unit 100 or the indoor unit 100 to the heat source side pipeline 500 by controlling the opening of the pressure relief valve 900.

[0040] It can be understood that through the corresponding pressure relief branch pipe 801 of each indoor unit 100, the leaked refrigerant can be transported to the pressure relief main pipe 802 when refrigerant leakage occurs in any indoor unit 100, so that each pressure relief branch pipe 801 does not need to be directly connected to the heat source side pipe 500, and through the connection of the pressure relief branch pipe 801 and the pressure relief main pipe 802, and then through the connection of the pressure relief main pipe 802, the leaked refrigerant of the indoor unit 100 corresponding to the pressure relief branch pipe 801 can be transported to the heat source side pipe 500 through the pressure relief main pipe 802, saving the pipe material for connecting each pressure relief branch pipe 801 to the heat source side pipe 500; and when each pressure relief branch pipe 801 is directly connected to the heat source side pipe 500, a pressure relief valve 900 needs to be installed in each pressure relief branch pipe 801, but the present application only needs to install one pressure relief valve 900 on the pressure relief main pipe 802 to achieve that when refrigerant leakage occurs in any indoor unit 100, the leaked refrigerant can be transported to the heat source side pipe 500 by opening the pressure relief valve 900, without the need to install multiple pressure relief valves 900.

[0041] In the embodiment of the present application, one end of the pressure relief main pipe 802 is communicated with the heat source side pipe 500, the other end is communicated with the indoor side pipe 400 of each indoor unit 100 through each pressure relief branch pipe 801, and the pressure relief valve 900 is arranged on the pressure relief main pipe 802, so that when refrigerant leakage occurs in the indoor unit 100 communicated by each pressure relief branch pipe 801, the refrigerant leaked in the indoor unit 100 or the indoor side pipe 400 can be transported to the pressure relief main pipe 802 through the pressure relief branch pipe 801, and then transported to the heat source side pipe 500 through the pressure relief main pipe 802, thereby realizing the timely transportation of the leaked refrigerant to the heat source side pipe 500 and avoiding pipe explosion of the indoor unit 100 or the indoor side pipe 400; and the leaked refrigerant of the indoor unit 100 corresponding to the pressure relief branch pipe 801 is transported to the heat source side pipe 500 through the pressure relief main pipe 802, saving the pipe material for connecting each pressure relief branch pipe 801 to the heat source side pipe 500; and the present application only needs to install one pressure relief valve 900 on the pressure relief main pipe 802 to achieve that when refrigerant leakage occurs in any indoor unit 100, the leaked refrigerant can be transported to the heat source side pipe 500 by opening the pressure relief valve 900, without the need to install multiple pressure relief valves 900, further saving installation materials.

[0042] Please refer to FIG. 2, further, the junction of the first branch gas pipe 3021 of the gas pipe 302 and the second branch gas pipe 201 of the first pipe 200 forms an indoor gas pipe 303, and the second refrigerant cutoff valve 602 is installed on the indoor gas pipe 303.

[0043] It can be understood that by installing the second refrigerant cutoff valve 602 on the indoor gas pipe 303 formed by the first branch gas pipe 3021 of the gas pipe 302 and the second branch gas pipe 201 of the first pipe 200, the refrigerant can be blocked from entering the indoor side pipe 400.

[0044] Further, the heating system further comprises: a first switching valve 701 and a second switching valve 702, each indoor unit 100 corresponds to a first switching valve 701 and a second switching valve 702, the first switching valve 701 is arranged in the first branch air pipe 3021, and the second switching valve 702 is arranged in the second branch air pipe 201. It can be understood that, since the first branch air pipe 3021 is a branch pipe of the air pipe 302, and the second branch air pipe 201 is a branch pipe of the second pipe 200, the communication of the refrigerant between the air pipe 302, the first pipe 200 and the indoor side pipe 400 can be controlled by the opening of the first switching valve 701 and the second switching valve 702.

[0045] Specifically, in the embodiment of the present application, the air pipe 302 transports high-pressure gas, and the first pipe 200 is a low-pressure gas pipe. When the first switching valve 701 is closed and the second switching valve 702 is opened, it means that the high-pressure gaseous refrigerant transported by the air pipe 302 cannot be transported to the indoor side pipe 400 through the first switching valve 701, and the indoor unit 100 cannot use the high-pressure gaseous refrigerant to release heat. When the second switching valve 702 is opened, the indoor unit 100 transports the liquid refrigerant through the first pipe 200 to absorb heat and change into gaseous refrigerant, and then transports the gaseous refrigerant to the indoor side pipe 400 through the opened second switching valve 702, and then transports the gaseous refrigerant to the indoor unit 100 through the indoor side pipe 400. Therefore, when the first switching valve 701 is closed and the second switching valve 702 is opened, the indoor unit 100 corresponding to the first switching valve 701 and the second switching valve 702 runs in the cooling mode. Similarly, when the first switching valve 701 is opened and the second switching valve 702 is closed, the high-temperature and high-pressure gaseous refrigerant is transported to the indoor unit 100 through the first switching valve 701, and the high-temperature and high-pressure gaseous refrigerant releases heat in the indoor unit 100 and changes into liquid refrigerant and is transported to the first pipe 200. Therefore, when the first switching valve 701 is opened and the second switching valve 702 is closed, the indoor unit 100 corresponding to the first switching valve 701 and the second switching valve 702 runs in the heating mode. In the embodiment of the present application, by controlling the opening and closing of the first switching valve 701 arranged on the first branch air pipe and the second switching valve 702 arranged on the second branch air pipe, the phase change of the refrigerant flowing into the indoor unit 100 corresponding to the first switching valve 701 and the second switching valve 702 can be controlled, so that the indoor unit 100 runs in the cooling mode and the heating mode.

[0046] It can be understood that in the embodiment of the present application, each indoor unit 100 has its corresponding first switch valve 701 and second switch valve 702, so that the operation mode of each indoor unit 100 can be controlled by controlling the opening of the first switch valve 701 and the second switch valve 702 corresponding to each indoor unit 100, and the same operation mode or different operation modes of different indoor units 100 can be simultaneously controlled in the heating and ventilation system.

[0047] For example, referring to FIG. 1, in FIG. 1, the heating and ventilation system includes two indoor units 100, the first switch valve 701 corresponding to the left indoor unit 100 can be controlled to be in an open state, and the second switch valve 702 can be controlled to be in a closed state; the first switch valve 701 corresponding to the right indoor unit 100 can be controlled to be in a closed state, and the second switch valve 702 can be controlled to be in an open state. Thus, the left indoor unit 100 is controlled to run in a heating mode, and the right indoor unit 100 is controlled to run in a cooling mode. By controlling the start of the mode switch valve, the indoor units 100 of the heating and ventilation system are controlled to run in different temperature adjustment modes.

[0048] Further, please continue to refer to FIG. 2, in the embodiment of the present application, one end of the pressure relief main pipe 802 is connected with the gas pipe 302, and the gas pipe 302 can be a high-pressure gas pipe, so that when the pressure relief valve 900 is opened, the refrigerant leaked from the indoor side pipe 400 can be transported to the gas pipe 302 through the pressure relief pipe 800.

[0049] Further, please refer to FIG. 3, in the embodiment of the present application, one end of the pressure relief main pipe 802 is connected with the first pipe 200, and the first pipe 200 can be a low-pressure gas pipe, so that when the pressure relief valve 900 is opened, the refrigerant leaked from the indoor side pipe 400 can be transported to the first pipe 200 through the pressure relief pipe 800. It can be understood that in the heating and ventilation system, the first pipe 200 has a larger pipe diameter, and the first pipe 200 is connected with a low-pressure tank, so that the refrigerant leaked from the indoor side pipe 400 can be more smoothly discharged from the first pipe 200.

[0050] Further, in the embodiment of the present application, a one-way valve 1000 can also be installed in the pressure relief branch pipe 801. Optionally, it can be installed at the middle position of the pressure relief branch pipe 801 or at the joint of the pressure relief branch pipe 801 and the pressure relief main pipe 802.

[0051] It can be understood that, in the present application, since each pressure relief branch pipe 801 is simultaneously connected to the pressure relief main pipe 802, and each indoor unit 100 is respectively connected to the pressure relief branch pipe 801, if any one indoor unit 100 is normally operating, that is, the first and second shutoff valves thereof do not cut off the refrigerant delivery, in order to avoid the refrigerant leaked in other indoor units 100 being delivered to the indoor unit 100 through the pressure relief branch pipe 801 corresponding to the indoor unit 100 via the connected pressure relief main pipe 802, affecting the normal operation of the indoor unit 100.

[0052] Further, referring to FIG. 3, in the embodiment of the present application, the pressure relief valve 900 includes two pressure relief valves 900, including a first pressure relief valve 9001 and a second pressure relief valve 9002.

[0053] The first pressure relief valve 9001 is arranged at the connection between the pressure relief main pipe 802 and the gas pipeline 302, and can be controlled to start to connect the pressure relief main pipe 802 and the gas pipeline 302. The first pressure relief valve 9001 can also be controlled to start to control the flow direction of the refrigerant, wherein it can control the flow direction of the refrigerant to the pressure relief main pipe 802 between the gas pipeline 302 and the first pipeline 200, and then to the first pipeline 200.

[0054] The second pressure relief valve 9002 is arranged at the connection between the pressure relief main pipe 802 and the first pipeline 200, and can be controlled to start to connect the pressure relief main pipe 802 and the first pipeline 200.

[0055] In the embodiment of the present application, by arranging the first pressure relief valve 9001 and the second pressure relief valve 9002 at the intersections of the main pipeline and the gas pipeline 302 and the first pipeline 200, it is realized that the refrigerant leaked in each indoor-side pipeline 400 can be delivered to any one of the gas pipeline 302 and the first pipeline 200.

[0056] Referring to FIG. 4, in the present application, the first pressure relief valve 9001 and the second pressure relief valve 9002 each include at least one pressure relief port.

[0057] Optionally, the first pressure relief valve 9001 includes a first pressure relief port 90011, a second pressure relief port 90012, a third pressure relief port 90013, and a fourth pressure relief port 90014; and the second pressure relief valve 9002 includes a fifth pressure relief port 90021.

[0058] When it is determined to discharge the refrigerant to the gas pipeline 302, the first pressure relief port 90011, the second pressure relief port 90012, and the fourth pressure relief port 90014 are started to connect the gas pipeline 302 and the pressure relief main pipeline 802, and the transmission process of the refrigerant is as follows: the refrigerant flows out from the pressure relief branch pipeline 801 connected with the indoor unit 100 to the pressure relief main pipeline 802, flows into the first pressure relief valve 9001 through the first pressure relief port 90011 along the pressure relief main pipeline 802, and flows to the third pressure relief port 90013 of the pressure relief main pipeline 802 between the gas pipeline 302 and the first pipeline 200 through the gas pipeline 302 since the first pressure relief valve 9001 is opened at the first pressure relief port 90011, the second pressure relief port 90012, and the fourth pressure relief port 90014, and the third pressure relief port 90013 is in a closed state, the refrigerant cannot be transmitted to the first pipeline 200 adjacent to the gas pipeline 302 through the third pressure relief port 90013, and the pressure of the refrigerant gathered in the indoor unit 100 is relatively large, so that the refrigerant moves to the left and right sides of the first pressure relief valve 9001 in the gas pipeline 302 when it is transmitted along the pressure relief branch pipeline 801 to the first pressure relief port 90011 of the first pressure relief valve 9001, and thus the refrigerant can be transported from the indoor unit 100 to the gas pipeline 302.

[0059] When it is determined to discharge the refrigerant to the first pipeline 200, the first pressure relief port 90011, the third pressure relief port 90013, and the fifth pressure relief port 90021 are started to connect the first pipeline 200 and the pressure relief main pipeline 802, and the transmission process of the refrigerant is as follows: the refrigerant flows out from the pressure relief branch pipeline 801 connected with the indoor unit 100 to the pressure relief main pipeline 802, flows into the first pressure relief valve 9001 through the first pressure relief port 90011 along the pressure relief main pipeline 802, and flows to the third pressure relief port 90013 of the pressure relief main pipeline 802 between the gas pipeline 302 and the first pipeline 200 through the gas pipeline 302 since the first pressure relief valve 9001 is opened at the first pressure relief port 90011 and the third pressure relief port 90013, and the second pressure relief port 90012 and the fourth pressure relief port 90014 on the left and right sides of the first pressure relief valve 9001 are in a closed state, the refrigerant cannot be transmitted to the gas pipeline 302 through the second pressure relief port 90012 and the fourth pressure relief port 90014, and the pressure of the refrigerant gathered in the indoor unit 100 is relatively large, so that the refrigerant moves to the left and right sides of the second pressure relief valve 9002 at the intersection of the first pipeline 200 and the pressure relief main pipeline 802 when it is transmitted along the pressure relief branch pipeline 801 to the first pressure relief port 90011 of the first pressure relief valve 9001, and the pressure at the first pressure relief port 90011 is relatively large, the refrigerant continues to flow to the pressure relief main pipeline 802 between the gas pipeline 302 and the first pipeline 200 through the third pressure relief port 90013, and then flows to the second pressure relief valve 9002 through the fifth pressure relief port 90021, and thus the refrigerant can be transported from the indoor unit 100 to the first pipeline 200.

[0060] It can be understood that, in the embodiments of the present application, the third pressure relief valve 9002 at the connection between the pressure relief main pipe 802 and the liquid pipe 301 can only include one pressure relief port, i.e., the ninth pressure relief port 90021. When the fifth pressure relief port 90021 is opened, the refrigerant can flow from the pressure relief main pipe 802 between the liquid pipe 301 and the first pipe 200 into the second pressure relief valve 9002 through the ninth pressure relief port 90021, and then into the first pipe 200 on both sides. In another embodiment, the second pressure relief valve can also include three pressure relief ports, and the other two pressure relief ports are respectively arranged at the positions of the liquid pipe 301 in the horizontal direction near the fifth pressure relief port 90021. When it is determined to transmit the refrigerant to the first pipe 200, the three pressure relief ports of the second pressure relief valve are started to transmit the refrigerant to the first pipe 200.

[0061] In the embodiments of the present application, by controlling the opening of the pressure relief ports of the corresponding first pressure relief valve 9001 and second pressure relief valve 9002, the refrigerant can be transmitted to any one of the gas pipe 302 and the first pipe 200.

[0062] Referring to the structural schematic diagrams shown in FIGS. 1-4, in an embodiment, when the first refrigerant cutoff valve 601 and the second refrigerant cutoff valve 602 of any indoor unit 100 are closed, the pressure value of the pressure relief valve 900 installed on the pressure relief main pipe 802 can be obtained, and then the pressure relief valve 900 is opened based on the pressure value to transmit the refrigerant leaked from the indoor side pipe 400 to the heat source side pipe 500 through the pressure relief pipe 800.

[0063] It can be understood that the refrigerant cutoff valve 600 can be used to control the flow of refrigerant of the indoor unit 100. After the refrigerant cutoff valve 600 is closed, there can still be refrigerant in the pipe of the indoor unit 100 and the indoor side pipe 400 that has not been discharged in time. In order to avoid the refrigerant leaked in the pipe of the indoor unit 100 and the indoor side pipe 400 from being affected by temperature and other factors to cause pipe explosion, the refrigerant in the pipe of the indoor unit 100 and the indoor side pipe 400 needs to be discharged to the heat source side pipe 500.

[0064] Optionally, in the present application, the refrigerant cutoff valve 600 corresponding to any indoor unit 100 can be closed when refrigerant leakage of the indoor unit 100 is detected, so as to timely close the refrigerant cutoff valve 600 to avoid continuous refrigerant leakage.

[0065] In addition, the refrigerant cutoff valve 600 can also be closed when the following abnormal working conditions occur:

[0066] The indoor unit 100 is in a shutdown state: when the indoor unit 100 is in a shutdown state, no refrigeration or heating is performed, and the refrigerant cutoff valve 600 of the indoor unit 100 is closed;

[0067] The indoor unit 100 is in a standby state: when the temperature in the space where the indoor unit 100 operates reaches the preset temperature, the indoor unit 100 enters the standby state, no longer performs refrigerant circulation, and the refrigerant shutoff valve 600 of the indoor unit 100 is closed;

[0068] The indoor unit 100 is in a blowing state: when the indoor unit 100 is in the blowing state, the indoor unit 100 operates to provide air conditioning flow, but does not perform cooling or heating, and thus the refrigerant shutoff valve 600 of the indoor unit 100 is closed;

[0069] The indoor unit 100 is in a fault state: when the indoor unit 100 is in the fault state, the indoor unit 100 cannot perform cooling or heating, and thus the refrigerant shutoff valve 600 of the indoor unit 100 is closed;

[0070] It can be understood that when any one of the above abnormal working conditions occurs in one of the multiple indoor units 100 of the heating and ventilation system, the refrigerant shutoff valve 600 corresponding to the indoor unit 100 can be controlled to be in a closed state; when the heating and ventilation system is in a power-off state, the heating and ventilation system controls all the refrigerant shutoff valves 600 corresponding to the indoor units 100 to be in a closed state.

[0071] When the refrigerant shutoff valve 600 corresponding to the indoor unit 100 is in a closed state, the leaked refrigerant in the indoor unit 100 cannot flow into the liquid pipe 301, the gas pipe 302, or the first pipe 200. When the pressure of the refrigerant leaked in the indoor unit 100 increases due to the increase in the ambient temperature of the space where the indoor unit 100 operates and other external factors, if the leaked refrigerant in the indoor unit 100 is not discharged in time to reduce the pressure in the indoor unit 100, the indoor unit 100 may explode and other safety problems may occur.

[0072] Therefore, in this embodiment, when the refrigerant shutoff valve 600 is closed, the pressure value of the pressure relief valve 900 on the pressure relief main pipe 802 is obtained, and it is determined whether to open the pressure relief valve 900 based on the pressure value, so that the refrigerant leaked from the indoor side pipe 400 is transported into the heat source side pipe 500 through the pressure relief pipe 800. The pressure value of the pressure relief valve 900 can be obtained by a pressure sensor.

[0073] Optionally, in this embodiment, there can be one or two pressure sensors. When there is only one pressure sensor, it can be installed at the inlet of the pressure relief valve 900, where the inlet of the pressure relief valve 900 is the position where the refrigerant flows into the pressure relief valve 900; when there are two pressure sensors, one pressure sensor can be installed at the inlet and the outlet of the pressure relief valve 900 respectively, where the outlet of the pressure relief valve 900 is the position where the refrigerant flows out of the pressure relief valve 900.

[0074] In the embodiment, there are two ways to control the opening of the pressure relief valve 900 based on the pressure value.

[0075] In one way, when there is one pressure sensor, the obtained pressure value is compared with a first pressure threshold value. When the pressure value is greater than the first pressure threshold value, the pressure relief valve 900 is opened, and the leaked refrigerant in the indoor unit 100 is transported from the indoor unit 100 to the heat source side pipeline 500 along the pressure relief pipeline 800.

[0076] The first pressure threshold value can be a pressure value used to determine whether to open the pressure relief valve 900.

[0077] For example, in the embodiment, the first pressure threshold value can be 3.5 MPa. When the pressure value obtained by the pressure sensor is 4 MPa, which is greater than the first pressure threshold value, the pressure relief valve 900 is opened, and the leaked refrigerant in the indoor unit 100 is discharged to the heat source pipeline.

[0078] In the embodiment, the pressure value obtained by the pressure sensor installed at the inlet of the pressure relief valve 900 is compared with the first pressure value to determine whether to open the pressure relief valve 900, which provides a basis for opening the pressure relief valve 900.

[0079] In another way, when there are two pressure sensors, the outlet pressure value obtained by the pressure sensor at the outlet of the pressure relief valve 900 and the inlet pressure value obtained by the pressure sensor at the inlet of the pressure relief valve 900 are obtained, and the pressure difference between the inlet pressure value and the outlet pressure value is determined. When the pressure difference is greater than a pressure difference threshold value, the pressure relief valve 900 is opened, and the leaked refrigerant in the indoor unit 100 is transported from the indoor unit 100 to the heat source pipeline along the pressure relief pipeline 800.

[0080] The pressure difference threshold value can be a value used to determine whether to open the pressure relief valve 900 according to the inlet pressure value and the outlet pressure value.

[0081] Optionally, since the outlet pressure value is obtained at the outlet of the pressure relief valve 900, and the pressure relief valve 900 is connected to the pressure relief main pipeline 802 and the heat source pipeline, when the heat source pipeline is a pipeline of different types, the outlet pressure value has a large difference. Therefore, in the embodiment, the pressure difference threshold value can also be selected according to the different target pipelines.

[0082] For example, when the heat source pipeline is the first pipeline 200, the pressure difference threshold value can be 0.75 MPa; and when the heat source pipeline is the gas pipeline 302, the pressure difference threshold value can be 0.85 MPa. By determining the corresponding pressure difference threshold value according to the heat source pipeline, it can be accurately determined whether to open the pressure relief valve 900.

[0083] In an embodiment, the heat source side pipeline can be the gas pipeline 302, the pressure difference threshold value is 0.85 MPa, the outlet pressure value obtained by the pressure sensor at the outlet of the pressure relief valve 900 is 2 MPa, and the inlet pressure value obtained by the pressure sensor at the inlet of the pressure relief valve 900 is 3.3 MPa, the pressure relief valve 900 is started, and the refrigerant delivered into the pressure relief main pipeline 802 is discharged into the gas pipeline 302.

[0084] In the embodiments of the present application, whether the pressure relief valve 900 is started is determined by the pressure difference between the inlet and outlet of the pressure relief valve 900 and the pressure difference threshold value, which provides a basis for determining whether the pressure relief valve 900 is started.

[0085] In the embodiments of the present application, the refrigerant leaked from the indoor unit 100 is delivered into the pressure relief main pipeline 802 through the pressure relief branch pipeline 801 connected with the indoor unit 100, and the pressure relief valve 900 in the pressure relief main pipeline 802 is started based on the pressure value of the pressure relief valve 900, and the refrigerant is delivered from the pressure relief main pipeline 802 to the heat source side pipeline 500. The pressure relief valve 900 is installed in the pressure relief main pipeline 802, and the starting of the pressure relief valve 900 is controlled, so that it is not necessary to install a corresponding pressure relief valve 900 for each indoor unit 100 of the air conditioning system, and the refrigerant pressure in each indoor unit 100 can be changed directly by controlling the opening of the pressure relief valve 900 in the pressure relief main pipeline 802, which simplifies the control of the refrigerant pressure in the indoor unit 100 of the air conditioning system and avoids safety problems.

[0086] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the program can be stored in a computer readable storage medium, and the program can include the processes of the above-mentioned embodiments when executed.

[0087] The above only describes the preferred embodiments of the present application, and of course cannot limit the scope of the present application, and equivalent changes made according to the claims of the present application are still within the scope of the present application.

Claims

1. A heating ventilation system wherein, The heating system comprises a heat source unit, a plurality of indoor units, a refrigerant cutoff valve, a heat source side pipeline connected with the heat source unit, an indoor side pipeline connected with each of the indoor units, a plurality of pressure relief pipelines, a plurality of pressure relief valves, and a gas-liquid separator; wherein the heat source side pipeline is connected with the indoor side pipeline through the refrigerant cutoff valve; The heat source side pipeline comprises a first pipeline, a second pipeline, a gas pipeline, and a liquid pipeline; and the refrigerant cutoff valve comprises a first refrigerant cutoff valve and a second refrigerant cutoff valve; The gas-liquid separator is connected with the second pipeline to separate the refrigerant of the second pipeline into liquid refrigerant and gaseous refrigerant; the gaseous refrigerant is delivered to the indoor side pipeline through the gas pipeline; the liquid refrigerant is delivered to the indoor side pipeline through the liquid pipeline; the first refrigerant cutoff valve is connected with the liquid pipeline; the second refrigerant cutoff valve is connected with the gas pipeline and the first pipeline; one end of the pressure relief pipeline is connected with the heat source side pipeline; the other end of the pressure relief pipeline is connected with the indoor side pipeline; and the pressure relief valve is arranged on the pressure relief pipeline; When the first refrigerant cutoff valve and the second refrigerant cutoff valve are closed and the pressure of the indoor side pipeline is greater than a safety threshold, the pressure relief valve is opened, and the refrigerant of the indoor side pipeline is released into the heat source side pipeline through the pressure relief pipeline.

2. The system of claim 1, wherein, The pressure relief pipeline comprises a pressure relief main pipeline and a plurality of pressure relief branch pipelines, each of which corresponds to at least one indoor unit; One end of each of the pressure relief branch pipelines is connected with the indoor side pipeline of the corresponding indoor unit; the other end of each of the pressure relief branch pipelines is connected with the pressure relief main pipeline; and the outlet end of the pressure relief main pipeline is connected with the heat source side pipeline.

3. The system of any of claims 1-2, wherein, The system further comprises a one-way valve; The one-way valve is arranged on each of the pressure relief branch pipelines.

4. The system of any of claims 1-3, wherein, The heat source side pipeline further comprises a refrigeration liquid header, a heating liquid header, a high-pressure gas header, and a low-pressure gas header.

5. The system of claim 4, wherein, The system further comprises a liquid pipeline unit and a gas pipeline unit; the first refrigerant cutoff valve is connected with the refrigeration liquid header and the heating liquid header through the liquid pipeline unit; and the second refrigerant cutoff valve is connected with the high-pressure gas header and the low-pressure gas header through the gas pipeline unit.

6. The system of claim 5, wherein, The liquid pipeline unit comprises an indoor unit liquid pipeline and a first liquid branch pipeline and a second liquid branch pipeline branched from the indoor unit liquid pipeline; one end of the first liquid branch pipeline is connected with the heating liquid header; and one end of the second liquid branch pipeline is connected with the refrigeration liquid header.

7. The system of claim 5, wherein, The gas pipeline unit comprises an indoor unit gas pipeline and a first gas branch pipeline and a second gas branch pipeline branched from the indoor unit gas pipeline; a first switch valve is arranged on the first gas branch pipeline; and a second switch valve is arranged on the second gas branch pipeline.

8. The system of claim 7, wherein, The first pipeline is a low-pressure gas pipeline; and the gas pipeline is a high-pressure gas pipeline. When the first switch valve is closed and the second switch valve is opened, the indoor units corresponding to the first switch valve and the second switch valve operate in a refrigeration mode.

9. The system of claim 7, wherein, The first pipeline is a low-pressure gas pipeline; and the gas pipeline is a high-pressure gas pipeline. When the first switch valve is opened and the second switch valve is closed, the indoor units corresponding to the first switch valve and the second switch valve operate in a heating mode.

10. The system of any of claims 1-9, wherein, One end of the pressure relief main pipe is connected with the gas pipe; The pressure relief valve is opened to transport the leaked refrigerant in the indoor side pipe to the gas pipe through the pressure relief pipe.

11. The system of any of claims 1-9, wherein, One end of the pressure relief main pipe is connected with the first pipe; The pressure relief valve is opened to transport the leaked refrigerant in the indoor side pipe to the first pipe through the pressure relief pipe.

12. The system of claim 2, wherein, The pressure relief valve comprises: A first pressure relief valve is arranged at the connection between the pressure relief main pipe and the gas pipe to connect the pressure relief main pipe and the gas pipe; A second pressure relief valve is arranged at the connection between the pressure relief main pipe and the first pipe to connect the pressure relief main pipe and the first pipe.

13. The system of claim 12, wherein, The first pressure relief valve comprises a first pressure relief port, a second pressure relief port, a third pressure relief port and a fourth pressure relief port, and the second pressure relief valve comprises a fifth pressure relief port; The first pressure relief port, the second pressure relief port and the fourth pressure relief port are activated to connect the gas pipe and the pressure relief main pipe; The first pressure relief port, the third pressure relief port and the fifth pressure relief port are activated to connect the first pipe and the pressure relief main pipe.

14. The system of any one of claims 1-13, wherein, When the first refrigerant cutoff valve and the second refrigerant cutoff valve are closed, the pressure value of the pressure relief valve is obtained; Based on the pressure value, the pressure relief valve is opened to transport the leaked refrigerant in the indoor unit to the heat source side pipe through the pressure relief pipe.

15. The system of claim 14, wherein, The pressure value comprises an inlet pressure value and an outlet pressure value of the pressure relief valve; The pressure difference between the inlet pressure value and the outlet pressure value is determined; When the pressure difference is greater than a pressure difference threshold value, the pressure relief valve is activated.

16. The system of claim 14, wherein, The pressure value is the inlet pressure value of the pressure relief valve; When the inlet pressure value is greater than a first pressure threshold value, the pressure relief valve is activated.

17. The system of claim 12, wherein, When it is detected that any of the indoor units has refrigerant leakage, the first refrigerant cutoff valve and the second refrigerant cutoff valve of the indoor unit are closed.

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