Indoor unit, control method of indoor unit and heating and ventilation equipment

Abstract

The invention discloses an indoor unit, a control method of the indoor unit and heating and ventilation equipment. The indoor unit comprises a pipeline assembly, a first one-way valve, a second one-way valve, a first convection heat exchanger, a third one-way valve, a second convection heat exchanger, a fourth one-way valve, a radiation heat exchanger and a fifth one-way valve. The pipeline assembly comprises a main pipeline, a first branch pipeline, a second branch pipeline and a third branch pipeline; the first one-way valve is arranged on the main pipeline; the second one-way valve is arranged on the first pipe section, and the first convection heat exchanger is arranged on the second pipe section; the third one-way valve and the second convection heat exchanger are arranged on the second branch pipeline; the fourth one-way valve and the radiation heat exchanger are arranged on the third branch pipeline; one end of the fifth one-way valve is connected between the second convection heat exchanger and the third one-way valve, and the other end of the fifth one-way valve is connected to the inlet side of the first one-way valve. The heating and ventilation equipment is high in comfort degree and low in energy consumption.

Description

Technical Field

[0001] This application relates to the technical field of air conditioners, and particularly to an indoor unit, a control method for the indoor unit, and a heating and ventilation equipment applying the indoor unit. Background Art

[0002] In an air conditioning system, the comfort level brought to users by the air conditioning system and the energy consumption of the air conditioning system are important factors determining the performance of the air conditioning system.

[0003] In the related art, a heat exchanger for heat exchange with indoor air is equipped in the indoor unit of the air conditioning system, and most of the heat exchangers selected are either a convection heat exchanger or a radiation heat exchanger. Among them, the convection heat exchanger is a heat exchanger that realizes heat energy transmission through the flow of fluid, and the radiation heat exchanger is a heat exchanger that works based on the principle of thermal radiation.

[0004] However, the indoor unit in the above air conditioning system cannot balance high comfort and low system energy consumption. Summary of the Invention

[0005] The main purpose of this application is to provide an indoor unit, a control method for the indoor unit, and a heating and ventilation equipment, which can reduce system energy consumption while improving the comfort level of the heating and ventilation equipment.

[0006] In a first aspect, this application provides an indoor unit, including a pipeline assembly, a first one-way valve, a second one-way valve, a first convection heat exchanger, a third one-way valve, a second convection heat exchanger, a fourth one-way valve, a radiation heat exchanger, and a fifth one-way valve; the pipeline assembly includes a main pipeline, a first branch pipeline, a second branch pipeline, and a third branch pipeline. The first branch pipeline and the second branch pipeline are respectively connected in parallel to the main pipeline. One end of the third branch pipeline is connected to the first branch pipeline, dividing the first branch pipeline into a first pipe section and a second pipe section. The other end of the third branch pipeline is connected to the main pipeline; the first one-way valve is arranged on the main pipeline; the second one-way valve is arranged on the first pipe section, and the first convection heat exchanger is arranged on the second pipe section; the third one-way valve and the second convection heat exchanger are arranged on the second branch pipeline; the fourth one-way valve and the radiation heat exchanger are arranged on the third branch pipeline; one end of the fifth one-way valve is connected between the second convection heat exchanger and the third one-way valve, and the other end of the fifth one-way valve is connected to the inlet side of the first one-way valve.

[0007] As an optional implementation manner, the pipeline assembly further includes a fourth branch pipeline for bypassing the main pipeline; the fifth one-way valve is arranged on the fourth branch pipeline.

[0008] As an optional implementation manner, the indoor unit provided by this application further includes a throttle valve, and the throttle valve is arranged on the main pipeline.

[0009] As an alternative embodiment, the throttle valve is an electronic expansion valve.

[0010] As an alternative embodiment, the first convective heat exchanger and the second convective heat exchanger are shell-and-tube heat exchangers.

[0011] As an alternative embodiment, the radiation heat exchanger is a radiation heat exchange plate.

[0012] In a second aspect, the present application provides a control method for an indoor unit, including controlling the first one-way valve, the second one-way valve, and the third one-way valve to open, and controlling the fourth one-way valve and the fifth one-way valve to close to switch the indoor unit to the cooling mode.

[0013] The control method for the indoor unit provided by the present application includes controlling the first one-way valve, the second one-way valve, and the third one-way valve to close, and controlling the fourth one-way valve and the fifth one-way valve to open to switch the indoor unit to the heating mode.

[0014] The control method for the indoor unit provided by the present application further includes controlling the throttle valve to be in the fully open state when the indoor unit is switched to the heating mode.

[0015] In a third aspect, the present application further provides a heating, ventilation, and air conditioning (HVAC) device, including an outdoor unit and the above-mentioned indoor unit connected together.

[0016] As an alternative embodiment, there are multiple indoor units, and the multiple indoor units are connected in parallel with each other.

[0017] In the indoor unit, the control method for the indoor unit, and the HVAC device according to the embodiments of the present application, when the indoor unit is in the cooling mode, the first one-way valve, the second one-way valve, and the third one-way valve are open, and the fourth one-way valve and the fifth one-way valve are closed, so that the flow paths where the first convective heat exchanger and the second convective heat exchanger are located can be connected in parallel. In this way, when the indoor unit is in the cooling mode, the flow rate of the refrigerant flowing in the flow path where the first convective heat exchanger is located and the flow rate of the refrigerant flowing in the flow path where the second convective heat exchanger is located are relatively small, and the frictional force formed between the refrigerant and the pipeline is relatively small. Thus, the pressure loss of the refrigerant can be reduced, thereby reducing the energy consumption of the entire HVAC device;

[0018] In the heating mode of the indoor unit, the first check valve, the second check valve, and the third check valve are closed, the fourth check valve and the fifth check valve are opened, and the first convection heat exchanger, the radiation heat exchanger, and the second convection heat exchanger are connected in series in sequence. Among them, the first convection heat exchanger is responsible for quickly raising the air temperature and spreading the heat rapidly to the surrounding environment. Subsequently, the radiation heat exchanger directly transfers the heat, and this method is not affected by air flow and can provide a direct and lasting warm feeling. The second convection heat exchanger heats again by convection to ensure that the heat distribution in the air is more uniform and prevent local overheating or uneven heating and cooling. In this way, the heating efficiency of the HVAC equipment provided by the embodiments of the present application is more efficient, and the comfort of users is higher in the heating mode. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0020] Figure 1 Structural schematic diagram of the indoor unit provided by the embodiments of the present application;

[0021] Figure 2 Flow chart of the refrigerant in the indoor unit provided in this embodiment in the cooling mode;

[0022] Figure 3 Flow chart of the refrigerant in the indoor unit provided in this embodiment in the heating mode.

[0023] Explanation of the reference numerals in the drawings:

[0024] 1. First convection heat exchanger; 2. Radiation heat exchanger; 3. Second convection heat exchanger; 4. Refrigeration flow path; 5. Heating flow path; 6. Throttle valve; 7. First check valve; 8. Second check valve; 9. Third check valve;

[0025] 10. Indoor unit; 41. First branch flow path; 42. Second branch flow path; 20. Pipeline assembly;

[0026] 110. Fourth check valve; 120. Fifth check valve; 201. Main pipeline; 202. First branch pipeline; 203. Second branch pipeline; 204. Third branch pipeline; 205. Fourth branch pipeline;

[0027] 2021. First pipe section; 2022. Second pipe section.

[0028] The realization of the purpose of the present application, functional features, and advantages will be further described in combination with the embodiments with reference to the drawings. Detailed implementation manners

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0030] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If this specific posture changes, the directional indication will also change accordingly.

[0031] In addition, in the present application, descriptions such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0032] In the present application, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0033] In addition, the technical solutions between various embodiments of the present application can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0034] In the related art, a heat exchanger for heat exchange with indoor air is equipped in the indoor unit of an air conditioning system, and most of the heat exchangers selected are either a convection heat exchanger or a radiation heat exchanger.

[0035] Among them, a convective heat exchanger refers to a heat exchanger that realizes heat energy transfer through the flow of fluid. By adjusting the air flow rate, rapid and precise adjustment of the heat exchange capacity can be achieved, and it can better adapt to intermittent operation and variable working conditions. However, the noise and blowing sensation during its operation greatly limit the comfort of the heat exchanger.

[0036] A radiative heat exchanger is a heat exchanger that works based on the principle of thermal radiation. It realizes heat exchange through natural convection formed by the temperature difference between the surface of the heat exchanger and the indoor air, and thermal radiation formed by the temperature difference between the surface of the heat exchanger and the indoor human body and objects. It is superior to the convective heat exchanger in terms of noise and blowing sensation. However, due to the small heat transfer coefficient between this heat exchanger and the indoor environment, the time interval from startup to stable heat supply is long and the intermittent performance is poor, which is not conducive to reducing the energy consumption of the air conditioning system.

[0037] Therefore, the air conditioning systems in the related technologies cannot take into account both comfort and low energy consumption.

[0038] Thus, this embodiment provides an indoor unit and a heating, ventilation, and air conditioning (HVAC) device. By improving the flow path of the refrigerant in the indoor unit in the cooling mode and the heating mode, the HVAC device provided in this embodiment has relatively high comfort and low energy consumption.

[0039] It should be noted that the HVAC device provided in this embodiment can be an air conditioning system. Exemplarily, it can be a multi-connected air conditioning system in an air conditioning system. Here, the specific type of the HVAC device provided in this embodiment is not limited.

[0040] The following will introduce the embodiments of the present application in detail with reference to the drawings and specific implementation manners.

[0041] Please refer to Figures 1 to 3 , Figure 1 , which is a schematic structural diagram of the indoor unit provided in the embodiment of the present application, Figure 2 , which is a flow chart of the refrigerant flow in the indoor unit provided in this embodiment in the cooling mode, Figure 3 , which is a flow chart of the refrigerant flow in the indoor unit provided in this embodiment in the heating mode. Among them, the arrow direction is the refrigerant flow direction, and the dashed line means that in the corresponding mode, the refrigerant does not flow through this place.

[0042] As shown in the figure, this embodiment provides an indoor unit 10, including a pipeline assembly 20. The pipeline assembly 20 includes a main pipeline 201, a first branch pipeline 202, a second branch pipeline 203, and a third branch pipeline 204. The first branch pipeline 202 and the second branch pipeline 203 are respectively connected in parallel to the main pipeline 201. One end of the third branch pipeline 204 is connected to the first branch pipeline 202, dividing the first branch pipeline 202 into a first pipe section 2021 and a second pipe section 2022. The other end of the third branch pipeline 204 is connected to the main pipeline 201.

[0043] Among them, the main pipeline 201 can be understood as the pipeline connected to the pipeline of the outdoor unit, while the first branch pipeline 202, the second branch pipeline 203 and the third branch pipeline 204 are the refrigerant flow pipelines for heat exchange with the indoor environment when the indoor unit 10 is in the cooling mode or the heating mode. It should be noted that the refrigerant here can be the refrigerant medium.

[0044] Furthermore, in order to overcome the defects in the related art, the indoor unit 10 provided in this embodiment further includes a first check valve 7, a second check valve 8, a first convection heat exchanger 1, a third check valve 9, a second convection heat exchanger 3, a fourth check valve 110, a radiation heat exchanger 2, and a fifth check valve 120. Among them, the first check valve 7 is arranged on the main pipeline 201, the second check valve 8 is arranged on the first pipe section 2021, the first convection heat exchanger 1 is arranged on the second pipe section 2022, the third check valve 9 and the second convection heat exchanger 3 are arranged on the second branch pipeline 203, the fourth check valve 110 and the radiation heat exchanger 2 are arranged on the third branch pipeline 204, one end of the fifth check valve 120 is connected between the second convection heat exchanger 3 and the third check valve 9, and the other end of the fifth check valve 120 is connected to the inlet side of the first check valve 7.

[0045] Furthermore, the above pipeline assembly 20 further includes a fourth branch pipeline 205 for bypassing the main pipeline 201, and the fifth check valve 120 is arranged on the fourth branch pipeline 205. That is to say, through the setting of the fifth check valve 120, when the indoor unit 10 is in the cooling mode, the flow path where the fifth check valve 120 is located is bypassed.

[0046] Specifically, please refer to Figure 2 As shown, when the indoor unit 10 is in the cooling mode, the first check valve 7, the second check valve 8, and the third check valve 9 are opened, and the fourth check valve 110 and the fifth check valve 120 are closed. At this time, a cooling flow path 4 is formed. The cooling flow path 4 includes a first branch flow path 41 and a second branch flow path 42 connected in parallel with each other. Here, the first branch flow path 41 is the flow path formed when the refrigerant flows in the above-mentioned first branch pipeline 202, and the second branch flow path 42 is the flow path formed when the refrigerant flows in the above-mentioned second branch pipeline 203. The upstream end of the first branch flow path 41 intersects with the upstream end of the second branch flow path 42, and the downstream end of the first branch flow path 41 intersects with the downstream end of the second branch flow path 42.

[0047] Among them, on the first branch flow path 41, the second check valve 8 is located on the upstream side of the first convection heat exchanger 1, and on the second branch flow path 42, the third check valve 9 is located on the downstream side of the second convection heat exchanger 3.

[0048] In this way, when the indoor unit 10 provided in the present embodiment is in the cooling mode, compared with the method of having only one flow path in the related art, the refrigerant flow rate flowing in the first branch flow path 41 and the refrigerant flow rate flowing in the second branch flow path 42 are both smaller, and the friction force formed between the refrigerant and the first branch pipeline 202 and the second branch pipeline 203 is smaller, thereby reducing the pressure loss of the refrigerant, thereby reducing the energy consumption of the entire HVAC equipment; moreover, at a lower flow rate, the fluid tends to be in a laminar state, and less turbulence is generated, so the pressure loss will also be relatively small.

[0049] In addition, by forming a flow path in which the first branch flow path 41 is connected in parallel with the second branch flow path 42, more refrigerant can come into contact with the air in the same unit time, thereby improving the cooling capacity of the entire system; moreover, the flow paths arranged in parallel can distribute the cooling capacity more evenly, avoid local overcooling or overheating, and improve the comfort of the entire system.

[0050] It should be noted that, in the cooling mode, the radiation heat exchanger 2 can be understood as being connected between the inlet of the first countercurrent heat exchanger 1 and the inlet of the second countercurrent heat exchanger 3. In this way, after the diversion, since the pressures on the inlet sides of the first countercurrent heat exchanger 1 and the second countercurrent heat exchanger 3 are almost equal, there is no pressure difference on both sides of the radiation heat exchanger 2. In this way, there will be no driving force to drive the refrigerant to flow through the radiation heat exchanger 2, thereby avoiding condensation on the surface of the radiation heat exchanger 2.

[0051] Among them, if the refrigerant flows through the radiation heat exchanger 2, the refrigerant will absorb the heat in the room during the process of flowing through the radiation heat exchanger 2, causing the refrigerant to evaporate and take away the heat, thereby lowering the indoor temperature. The temperature on the surface of the radiation heat exchanger 2 will drop due to the cooling effect of the refrigerant. This surface temperature will be lower than the dew point temperature of the indoor air, and the water vapor in the air will condense into liquid water on the surface of the radiation heat exchanger 2, resulting in condensation.

[0052] Please combine Figure 3 As shown, when the indoor unit 10 is in the heating mode, the first one-way valve 7, the second one-way valve 8, and the third one-way valve 9 are closed, and the fourth one-way valve 110 and the fifth one-way valve 120 are opened. At this time, a heating flow path 5 is formed, and the first counter-flow heat exchanger 1, the radiation heat exchanger 2 and the second counter-flow heat exchanger 3 are sequentially arranged on the heating flow path 5 along the flow direction of the refrigerant, and the fourth one-way valve 110 is located on the upstream side of the radiation heat exchanger 2, and the fifth one-way valve 120 is located on the downstream side of the second counter-flow heat exchanger 3.

[0053] When the indoor unit 10 provided in this embodiment is in the heating mode, the first convection heat exchanger 1 is responsible for quickly raising the air temperature, enabling the heat to rapidly spread to the surrounding environment. Subsequently, the radiation heat exchanger 2 directly transfers the heat. This method is not affected by air flow and can provide a direct and lasting warm feeling. The second convection heat exchanger 3 heats again by convection to ensure that the heat in the air is more evenly distributed, preventing local overheating or uneven heating and cooling.

[0054] It can be understood that combining the radiation and convection heating methods can create a warm feeling closer to the natural environment. The radiation heat exchanger 2 simulates the feeling of sunlight irradiation, while the first convection heat exchanger 1 and the second convection heat exchanger 3 provide warmth in the air. The combination enables users to feel a more comfortable and natural warmth.

[0055] In addition, using the radiation heat exchanger 2 can reduce the working burden of the first convection heat exchanger 1 and the second convection heat exchanger 3 because the demand for air heating is reduced while directly heating the object and the user. In this way, energy can be utilized more efficiently and unnecessary heat loss can be reduced.

[0056] Therefore, the indoor unit 10 provided in this embodiment can meet the requirements of high comfort and low energy consumption.

[0057] In some specific embodiments, the first convection heat exchanger 1 and the second convection heat exchanger 3 can be shell-and-tube heat exchangers; the radiation heat exchanger 2 can be a radiation heat exchange plate. Among them, the shell-and-tube heat exchanger includes a shell and internal tube bundles, and the refrigerant flows inside the tubes; the radiation heat exchange plate is mainly used to directly radiate heat to the surrounding environment or specific objects.

[0058] It should be noted that the above-mentioned first convection heat exchanger 1 and second convection heat exchanger 3 can also adopt other types, such as finned-tube heat exchangers, etc. The above-mentioned radiation heat exchanger 2 can also adopt other types, such as infrared radiation heating elements, etc. Here, the specific types of the first convection heat exchanger 1, the radiation heat exchanger 2, and the second convection heat exchanger 3 are not limited.

[0059] Of course, whether the indoor unit 10 is in the cooling or heating mode, it needs to work in coordination with the outdoor unit. Specifically, when in the cooling mode, the refrigerant first leaves the indoor unit 10 as a low-temperature and low-pressure gas, enters the compressor of the outdoor unit, and is compressed into a high-temperature and high-pressure gas. The high-temperature and high-pressure gaseous refrigerant enters the condenser of the outdoor unit, releases heat to the external air and is cooled, turning into a liquid. Then, the liquid refrigerant passes through a throttling device, the pressure decreases, and it becomes a low-temperature and low-pressure mixture. Finally, the refrigerant enters the indoor unit 10 again, absorbs the heat of the indoor air, and evaporates into a gas to complete the cycle.

[0060] When in the heating mode, the refrigerant first leaves the indoor unit 10 as a high-temperature and high-pressure liquid; through the throttling device, the pressure of the refrigerant decreases and it becomes a low-temperature and low-pressure mixed state. The mixed-state refrigerant enters the evaporator of the outdoor unit, absorbs the heat of the outside air, and evaporates into a gas. Then, the gaseous refrigerant enters the compressor and is compressed into a high-temperature and high-pressure gas. Finally, the high-temperature and high-pressure refrigerant enters the indoor unit 10, releases heat to the interior, cools and liquefies, completing the cycle.

[0061] That is to say, in the heating mode, the high-temperature and high-pressure gaseous refrigerant first undergoes forced convection heat transfer in the first convection heat exchanger 1 to become a high-temperature two-phase state, then enters the radiation heat exchanger 2 to conduct radiation heat transfer with the indoor environment, and finally enters the second convection heat exchanger 3 to conduct forced convection heat transfer to the subcooled state and flows to the outdoor unit. Thus, the serial connection of the first convection heat exchanger 1, the radiation heat exchanger 2, and the second convection heat exchanger 3 results in a smaller number of flow paths, so that the flow rate of the refrigerant in the heating flow path 5 is relatively fast, thereby increasing the heat transfer coefficient and improving the heat transfer efficiency.

[0062] That is to say, the flow direction of the refrigerant in the cooling mode is opposite to that in the heating mode.

[0063] Therefore, in order to achieve the above functions of the throttling device to control the flow rate of the refrigerant, the indoor unit 10 provided in this embodiment further includes a throttle valve 6. The throttle valve 6 is disposed on the main pipeline 201. Correspondingly, a throttle valve can also be provided in the outdoor unit. When the indoor unit 10 is in the cooling mode, the throttle valve 6 is located on the upstream side of the cooling flow path 4. And in the cooling mode, the main task of the throttle valve 6 is to throttle the high-pressure liquid refrigerant from the condenser of the outdoor unit to a low pressure, so that it evaporates in the first convection heat exchanger 1 and the second convection heat exchanger 3, thereby absorbing the heat in the interior. At this time, the opening degree of the throttle valve 6 is usually small to control an appropriate amount of refrigerant flowing into the first convection heat exchanger 1 and the second convection heat exchanger 3, ensuring that the refrigerant can fully evaporate in the first convection heat exchanger 1 and the second convection heat exchanger 3, and preventing liquid refrigerant from entering the compressor, causing "liquid slugging". Moreover, at this time, the throttle valve in the outdoor unit is in the fully open state to allow the refrigerant vapor to flow smoothly, facilitating the condensation process. Among them, the throttle valve 6 is an electronic expansion valve.

[0064] It should be noted that liquid slugging is a common failure phenomenon that occurs in the compressor. When liquid refrigerant or excessive liquid droplets are sucked into the compressor, liquid slugging will be triggered.

[0065] When the indoor unit 10 is in the heating mode, the throttle valve 6 is located on the downstream side of the heating flow path 5 and is fully open to allow the refrigerant to flow smoothly. At this time, the throttle valve in the outdoor unit controls the flow rate of the refrigerant from the high-pressure state to the low-pressure state, causing the refrigerant to evaporate in the evaporator outdoors and absorb the heat in the outdoor air. Therefore, the opening degree of the throttle valve in the outdoor unit will be adjusted according to the outdoor temperature and the indoor heat load demand.

[0066] More specifically, in the cooling mode, under the opening action of the second check valve 8 and the third check valve 9, the refrigerant is divided into two parts. After passing through the first convection heat exchanger 1 and the second convection heat exchanger 3, the two parts of the refrigerant converge and flow into the compressor of the outdoor unit, where it is compressed into a high-temperature and high-pressure gas state. The high-temperature and high-pressure gaseous refrigerant enters the condenser of the outdoor unit, releases heat to the outside air and is cooled, turning into a liquid state. Then, the liquid refrigerant passes through the throttle valve 6, the pressure decreases, and it becomes a low-temperature and low-pressure mixed state. Finally, the refrigerant flows through the first check valve 7, part of it flows through the second check valve 8 and the first convection heat exchanger 1, and the other part flows through the second convection heat exchanger 3. The radiation heat exchanger 2 is bypassed, so as to absorb the heat in the indoor air, evaporate into a gaseous state, and complete the cycle.

[0067] In the heating mode, the refrigerant first flows through the first convection heat exchanger 1, the fourth check valve 110, the radiation heat exchanger 2, the second convection heat exchanger 3, and the fifth check valve 120 in sequence and then flows to the throttle valve 6, and then flows into the throttle valve of the outdoor unit. At this time, the pressure of the refrigerant decreases and becomes a low-temperature and low-pressure mixed state. The mixed-state refrigerant enters the evaporator of the outdoor unit, absorbs the heat in the outside air, evaporates into a gaseous state, and then the gaseous refrigerant enters the compressor, where it is compressed into a high-temperature and high-pressure gaseous state. Finally, the high-temperature and high-pressure refrigerant flows through the first convection heat exchanger 1, the fourth check valve 110, the radiation heat exchanger 2, and the second convection heat exchanger 3 in sequence, releases heat to the indoor, cools and liquefies, and completes the cycle.

[0068] That is to say, under the combined and coordinated action of the first check valve 7, the second check valve 8, the third check valve 9, the fourth check valve 110, and the fifth check valve 120, the cooling flow path 4 of the indoor unit 10 in the cooling mode and the heating flow path 5 of the indoor unit 10 in the heating mode provided by this embodiment are formed.

[0069] This embodiment also provides a control method for an indoor unit, including controlling the first check valve, the second check valve, and the third check valve to open, and controlling the fourth check valve and the fifth check valve to close to switch the indoor unit to the cooling mode; or, controlling the first check valve, the second check valve, and the third check valve to close, and controlling the fourth check valve and the fifth check valve to open to switch the indoor unit to the heating mode.

[0070] Among them, the indoor unit 10 switches to the cooling mode, which can be switched from the shutdown mode to the cooling mode, or from the standby mode to the cooling mode, or from the heating mode to the cooling mode; and when the indoor unit 10 switches to the heating mode, it can be switched from the shutdown mode to the heating mode, or from the standby mode to the heating mode, or from the cooling mode to the heating mode. Here, there is no specific limitation on the state of the indoor unit 10 before it is in the cooling mode or the heating mode.

[0071] Furthermore, the control method of the indoor unit provided in this embodiment further includes controlling the throttle valve to be in a fully open state when the indoor unit switches to the heating mode.

[0072] As can be seen from the above implementation, in the heating mode, the throttle valve 6 is located on the downstream side of the heating flow path 5, and the throttle valve 6 is in a fully open state to allow the refrigerant to flow smoothly.

[0073] Of course, the control method of the indoor unit provided in this embodiment further includes turning on the indoor unit before the indoor unit switches to the cooling mode or before the indoor unit switches to the heating mode, so that the indoor unit is in the working mode. Here, there is no specific limitation on other conventional steps included in the control method of the indoor unit.

[0074] This embodiment also provides a heating and ventilation equipment, including an outdoor unit and the indoor unit 10 in the above implementation, which are connected together. Among them, the structure of the indoor unit 10 has been introduced in detail in the above implementation, and will not be elaborated here.

[0075] It can be understood that the outdoor unit in the heating and ventilation equipment provided in this embodiment should also include a compressor, an outdoor unit heat exchanger, etc. Of course, it can also include a throttling device such as a throttle valve.

[0076] Of course, the heating and ventilation equipment provided in this embodiment should also include an electric control component, etc. Here, there is no specific limitation on the modules included in the heating and ventilation equipment provided in this embodiment.

[0077] It should be noted that the heating and ventilation equipment provided in this embodiment can be a multi-connected air-conditioning system, that is, there are multiple indoor units 10, and the multiple indoor units 10 are connected in parallel. Among them, the refrigerant flow path of each indoor unit 10 in the cooling mode and the heating mode can refer to the refrigerant flow path in the above implementation. Here, the refrigerant flow path of the entire system will not be introduced in detail.

[0078] Since the heating and ventilation equipment provided in this embodiment adopts the indoor unit 10 in the above implementation, the comfort of the heating and ventilation equipment provided in this embodiment is relatively high and the system energy consumption is relatively low, so that the performance of the heating and ventilation equipment provided in this embodiment is relatively good.

[0079] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural transformation made under the concept of the present application by using the content of the specification and drawings of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. An indoor unit, characterized in that, Comprising: A pipeline assembly, the pipeline assembly includes a main pipeline, a first branch pipeline, a second branch pipeline and a third branch pipeline. The first branch pipeline and the second branch pipeline are respectively connected in parallel to the main pipeline. One end of the third branch pipeline is connected to the first branch pipeline, separating the first branch pipeline into a first pipe section and a second pipe section, and the other end of the third branch pipeline is connected to the main pipeline; A first check valve, arranged on the main pipeline; A second check valve and a first convection heat exchanger, the second check valve is arranged on the first pipe section, and the first convection heat exchanger is arranged on the second pipe section; A third check valve and a second convection heat exchanger, arranged on the second branch pipeline; A fourth check valve and a radiation heat exchanger, arranged on the third branch pipeline; And A fifth check valve, one end of the fifth check valve is connected between the second convection heat exchanger and the third check valve, and the other end of the fifth check valve is connected to the inlet side of the first check valve.

2. The indoor unit according to claim 1, characterized in that, The pipeline assembly further includes a fourth branch pipeline for bypassing the main pipeline; The fifth check valve is arranged on the fourth branch pipeline.

3. The indoor unit according to claim 2, characterized in that, It further includes a throttle valve, and the throttle valve is arranged on the main pipeline.

4. The indoor unit according to claim 3, characterized in that, The throttle valve is an electronic expansion valve.

5. The indoor unit according to any one of claims 1 to 4, characterized in that The first convection heat exchanger and the second convection heat exchanger are shell-and-tube heat exchangers; and / or, The radiation heat exchanger is a radiation heat exchange plate.

6. A control method for an indoor unit, characterized in that, Comprising: Controlling the first check valve, the second check valve and the third check valve to open, and controlling the fourth check valve and the fifth check valve to close to switch the indoor unit to the cooling mode; or, Controlling the first check valve, the second check valve and the third check valve to close, and controlling the fourth check valve and the fifth check valve to open to switch the indoor unit to the heating mode.

7. The control method of the indoor unit according to claim 6, characterized in that, It further includes: When the indoor unit is switched to the heating mode, controlling the throttle valve to be in the fully open state.

8. The control method of the indoor unit according to claim 7, characterized in that, The throttle valve is an electronic expansion valve.

9. A heating, ventilation and air conditioning equipment, characterized in that, Comprising an outdoor unit and the indoor unit according to any one of claims 1 to 5 connected together.

10. The HVAC equipment according to claim 9, characterized in that, There are multiple indoor units, and the multiple indoor units are connected in parallel with each other.

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