Indoor unit and heating and ventilation equipment

Abstract

The utility model discloses an indoor unit and heating and ventilation equipment. The indoor unit comprises a first convection heat exchanger, a second convection heat exchanger and a radiation heat exchanger. A refrigeration flow path is formed in the indoor unit in a refrigeration mode, and the first convection heat exchanger and the second convection heat exchanger are sequentially arranged on the refrigeration flow path in the flowing direction of refrigerants. When the indoor unit is in a heating mode, a heating flow path is formed, and the second convection heat exchanger, the radiation heat exchanger and the first convection heat exchanger are sequentially arranged on the heating flow path in the flowing direction of refrigerants. The heating and ventilation equipment is high in comfort 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 and a heating and ventilation equipment using the same. Background Art

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

[0003] In related technologies, an indoor unit of an air conditioning system is equipped with a heat exchanger for heat exchange with indoor air. In most cases, a convection heat exchanger or a radiation heat exchanger is selected for the heat exchanger. Among them, a convection heat exchanger refers to a heat exchanger that realizes heat energy transfer through the flow of a fluid, and a 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 achieve both high comfort and low system energy consumption. Summary of the Utility Model

[0005] The main object of this application is to provide an indoor unit and a heating and ventilation equipment, which can improve the comfort level of the heating and ventilation equipment while reducing the system energy consumption.

[0006] On the one hand, this application provides an indoor unit, including a connection to a first convection heat exchanger, a second convection heat exchanger, and a radiation heat exchanger; a refrigeration flow path is formed when the indoor unit is in the refrigeration mode, and the first convection heat exchanger and the second convection heat exchanger are sequentially arranged on the refrigeration flow path along the refrigerant flow direction; a heating flow path is formed when the indoor unit is in the heating mode, and the second convection heat exchanger, the radiation heat exchanger, and the first convection heat exchanger are sequentially arranged on the heating flow path along the refrigerant flow direction.

[0007] As an optional implementation manner, the indoor unit provided in this application further includes a regulating valve; when the indoor unit is in the refrigeration mode, the regulating valve is opened, and the refrigerant flows from the first convection heat exchanger to the second convection heat exchanger via the regulating valve; when the indoor unit is in the heating mode, the regulating valve is closed, and the refrigerant does not flow through the regulating valve.

[0008] As an optional implementation manner, the regulating valve is a solenoid valve or a check valve.

[0009] As an optional implementation manner, the indoor unit provided in this application further includes a regulating valve, and the regulating valve is a reversing valve; when the indoor unit is in the refrigeration mode, the refrigerant flows from the first convection heat exchanger to the second convection heat exchanger via the reversing valve; when the indoor unit is in the heating mode, the refrigerant flows from the second convection heat exchanger to the radiation heat exchanger via the reversing valve, and then flows from the radiation heat exchanger to the first convection heat exchanger via the reversing valve.

[0010] As an alternative embodiment, a defrost flow path is formed in the indoor unit in the defrost mode, and the first convective heat exchanger and the second convective heat exchanger are sequentially arranged on the defrost flow path along the refrigerant flow direction; when the indoor unit is in the defrost mode, there is no refrigerant flow in the radiation heat exchanger.

[0011] As an alternative embodiment, the indoor unit provided in the present application further includes a fan, and the fan is connected to the first convective heat exchanger.

[0012] As an alternative embodiment, the indoor unit provided in the present application further includes a fan, and the fan is connected to the second convective heat exchanger.

[0013] As an alternative embodiment, the indoor unit provided in the present application further includes an indoor throttle valve; when the indoor unit is in the cooling mode, the indoor throttle valve is located on the upstream side of the cooling flow path; when the indoor unit is in the heating mode, the indoor throttle valve is located on the downstream side of the heating flow path, and the indoor throttle valve is in a fully open state.

[0014] As an alternative embodiment, the indoor throttle valve is an electronic expansion valve.

[0015] As an alternative embodiment, both the first convective heat exchanger and the second convective heat exchanger are shell-and-tube heat exchangers.

[0016] As an alternative embodiment, the radiation heat exchanger is a radiation heat exchange plate.

[0017] On the other hand, the present application provides a heating, ventilation and air conditioning (HVAC) device, including an outdoor unit and the above-mentioned indoor unit connected together.

[0018] In the indoor unit and the HVAC device in the embodiments of the present application, when the indoor unit is in the cooling mode, the first convective heat exchanger and the second convective heat exchanger are sequentially arranged on the cooling flow path along the refrigerant flow direction. In this way, the refrigerant can be made not to flow to the radiation heat exchanger, which will make the surface temperature of the radiation heat exchanger always higher than the dew point temperature of the indoor air, thereby avoiding condensation to a certain extent; moreover, it can avoid cold air blowing caused by the too low surface temperature of the radiation heat exchanger to a certain extent, thereby improving the comfort of users; in addition, it can reduce the flow resistance of the refrigerant, improve the energy efficiency ratio of the HVAC device provided in the embodiments of the present application, and reduce energy consumption.

[0019] In the heating mode of the indoor unit, the second convective heat exchanger, the radiant heat exchanger, and the first convective heat exchanger are arranged in sequence on the heating flow path along the refrigerant flow direction. Among them, the second convective heat exchanger is responsible for quickly raising the air temperature and spreading the heat rapidly to the surrounding environment. Subsequently, the radiant heat exchanger directly transmits the heat, and this method is not affected by air flow and can provide a direct and lasting warm feeling. The first convective heat exchanger heats again by convection to ensure more uniform heat distribution in the air 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 in the heating mode, the comfort of users is higher. Brief Description of the Drawings

[0020] 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.

[0021] Figure 1 The first structure diagram of the HVAC equipment provided by the embodiments of the present application;

[0022] Figure 2 The second structure diagram of the HVAC equipment provided by the embodiments of the present application;

[0023] Figure 3 The third structure diagram of the HVAC equipment provided by the embodiments of the present application;

[0024] Figure 4 For Figure 1 The refrigerant flow diagram of the shown structure in the cooling state;

[0025] Figure 5 For Figure 2 The refrigerant flow diagram of the shown structure in the cooling state;

[0026] Figure 6 For Figure 3 The refrigerant flow diagram of the shown structure in the cooling state;

[0027] Figure 7 For Figure 1 The refrigerant flow diagram of the shown structure in the heating state;

[0028] Figure 8 For Figure 2 The refrigerant flow diagram of the shown structure in the heating state;

[0029] Figure 9 For Figure 3Refrigerant flow diagram of the shown structure in the heating state.

[0030] Explanation of the reference numerals in the attached drawings:

[0031] 2. Radiation heat exchanger; 3. Refrigeration flow path; 4. Heating flow path; 5. Indoor throttle valve; 6. Control valve; 7. Fan;

[0032] 10. Indoor unit; 11. First convective heat exchanger; 12. Second convective heat exchanger; 61. First valve port; 62. Second valve port; 63. Third valve port; 64. Fourth valve port; 20. Outdoor unit; 21. Compressor; 22. Gas-liquid separator; 23. Four-way reversing valve; 24. Outdoor heat exchanger; 25. Outdoor throttle valve;

[0033] 100. HVAC equipment.

[0034] The realization, functional features and advantages of the purpose of this application will be further described in combination with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in combination with 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 the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0036] It should be noted that all the 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 indications will also change accordingly.

[0037] In addition, the descriptions such as "first" and "second" in the present application 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, the 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 and clearly defined.

[0038] In this application, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] In addition, the technical solutions between various embodiments of this application can be combined with each other, but it must be based on the premise that those of ordinary skill in the art can implement them. 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 this application.

[0040] 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 in most cases, a convective heat exchanger or a radiative heat exchanger is selected for the heat exchanger.

[0041] Among them, a convective heat exchanger refers to a heat exchanger that realizes heat energy transmission through the flow of a 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 feeling during its operation greatly limit the comfort of this heat exchanger.

[0042] A radiative heat exchanger is a heat exchanger that works based on the principle of thermal radiation. It relies on the natural convection formed by the temperature difference between the surface of the heat exchanger and the indoor air, and the thermal radiation formed by the temperature difference with the indoor human body and the surface of objects to achieve heat exchange. It is superior to the convective heat exchanger in terms of noise and blowing feeling. 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.

[0043] Therefore, the air conditioning system in the related art cannot take into account both comfort and low energy consumption.

[0044] 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 by this embodiment has higher comfort and lower energy consumption.

[0045] It should be noted that the HVAC device provided by this embodiment can be an air conditioning system, specifically a single-unit air conditioning system or a multi-connected air conditioning system. Here, the specific type of the HVAC device provided by this embodiment is not limited.

[0046] The embodiments of the present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0047] Please refer to Figures 1 to 3 , Figure 1 which is the first structural schematic diagram of the heating, ventilation and air conditioning (HVAC) equipment provided by the embodiments of the present application, Figure 2 which is the second structural schematic diagram of the HVAC equipment provided by the embodiments of the present application, Figure 3 which is the third structural schematic diagram of the HVAC equipment provided by the embodiments of the present application.

[0048] As shown in the figure, the present embodiment provides an indoor unit 10, which includes a first convection heat exchanger 11, a second convection heat exchanger 12, and a radiant heat exchanger 2.

[0049] Please combine with Figures 4 to 6 , Figure 4 which is Figure 1 the refrigerant flow diagram of the structure shown in the cooling state, Figure 5 which is Figure 2 the refrigerant flow diagram of the structure shown in the cooling state, Figure 6 which is Figure 3 the refrigerant flow diagram of the structure shown in the cooling state. Among them, the arrow direction is the refrigerant flow direction.

[0050] As shown in the figure, when the indoor unit 10 is in the cooling mode, a cooling flow path 3 is formed. The first convection heat exchanger 11 and the second convection heat exchanger 12 are sequentially arranged on the cooling flow path 3 along the refrigerant flow direction. That is to say, when the refrigerant flows out of the outdoor unit 20, it will first flow through the first convection heat exchanger 11, and then flow through the second convection heat exchanger 12, and the refrigerant will not flow to the radiant heat exchanger 2. It should be noted that the refrigerant here can be a refrigerant medium.

[0051] In this way, the surface temperature of the radiant heat exchanger 2 will always be higher than the dew point temperature of the indoor air, so as to avoid condensation to a certain extent; moreover, it can avoid the cold air blowing caused by the too low surface temperature of the radiant heat exchanger 2 to a certain extent, thereby improving the comfort of users in the cooling mode; in addition, it can reduce the flow resistance of the refrigerant, improve the energy efficiency ratio, and reduce energy consumption.

[0052] Among them, if the refrigerant flows through the radiant heat exchanger 2, the refrigerant will absorb the indoor heat during the process of flowing through the radiant heat exchanger 2, resulting in the evaporation of the refrigerant and taking away the heat, thereby reducing the indoor temperature. The surface temperature of the radiant heat exchanger 2 will drop due to the cooling effect of the refrigerant, and 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 radiant heat exchanger 2, resulting in the condensation phenomenon.

[0053] Please continue to combine with Figures 7 to 9 ,Figure 7 is Figure 1 the refrigerant flow diagram of the structure shown in the heating state, Figure 8 is Figure 2 the refrigerant flow diagram of the structure shown in the heating state, Figure 9 is Figure 3 the refrigerant flow diagram of the structure shown in the heating state.

[0054] As shown in the figure, when the indoor unit 10 is in the heating mode, a heating flow path 4 is formed, and the second convection heat exchanger 12, the radiation heat exchanger 2, and the first convection heat exchanger 11 are sequentially arranged on the heating flow path 4 along the refrigerant flow direction. That is to say, when the refrigerant flows out of the outdoor unit 20, it will first flow through the second convection heat exchanger 12, then flow through the radiation heat exchanger 2, and finally flow through the first convection heat exchanger 11.

[0055] In this way, the second convection heat exchanger 12 is responsible for quickly raising the air temperature and spreading the heat rapidly to the surrounding environment. Then, the radiation heat exchanger 2 directly transmits the heat. This method is not affected by air flow and can provide a direct and lasting warm feeling. The first convection heat exchanger 11 heats again by convection to ensure that the heat in the air is more evenly distributed and prevent local overheating or uneven heating and cooling. In this way, the heating efficiency of the HVAC equipment 100 is more efficient, and the user's comfort is higher in the heating mode.

[0056] It can be understood that combining the radiation and convection heating methods can create a warmer feeling closer to the natural environment. The radiation heat exchanger 2 simulates the feeling of sunlight irradiation, while the first convection heat exchanger 11 and the second convection heat exchanger 12 provide warmth in the air. The combination of the two enables the user to feel a more comfortable and natural warmth.

[0057] In addition, using the radiation heat exchanger 2 can reduce the working burden of the first convection heat exchanger 11 and the second convection heat exchanger 12 because it reduces the need for air heating while directly heating objects and users. In this way, energy can be used more efficiently and unnecessary heat loss can be reduced.

[0058] Therefore, the indoor unit 10 provided in this embodiment can meet the requirements of high comfort and low energy consumption.

[0059] In some specific embodiments, the convection heat exchangers forming the first convection heat exchanger 11 and the second convection heat exchanger 12 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 for directly radiating heat to the surrounding environment or specific objects.

[0060] It should be noted that the above-mentioned first convective heat exchanger 11 and second convective heat exchanger 12 can also be formed by other types of convective heat exchangers, for example, finned-tube heat exchangers, etc. The above-mentioned radiant heat exchanger 2 can also adopt other types, such as infrared radiation heating elements, etc. Here, the specific types of the first convective heat exchanger 11, the radiant heat exchanger 2, and the second convective heat exchanger 12 are not limited.

[0061] Of course, whether in the cooling or heating mode, the indoor unit 10 needs to work in cooperation with the outdoor unit 20. Among them, the outdoor unit 20 includes a compressor 21, a gas-liquid separator 22, a four-way reversing valve 23, and an outdoor heat exchanger 24.

[0062] Specifically, in the cooling mode, the refrigerant first leaves the indoor unit 10 as a low-temperature and low-pressure gas state, flows through the gas-liquid separator 22, and then enters the compressor 21, where it is compressed into a high-temperature and high-pressure gas state. The high-temperature and high-pressure gaseous refrigerant flows into the outdoor heat exchanger 24, releases heat to the outside air and is cooled, and turns into a liquid state. Then, the liquid refrigerant passes through the throttling device, the pressure decreases, and it becomes a low-temperature and low-pressure mixed state. Finally, the refrigerant enters the indoor unit 10 again, absorbs the heat of the indoor air, and evaporates into a gas state to complete the cycle.

[0063] In the heating mode, the refrigerant first leaves the indoor unit 10 as a high-temperature and high-pressure liquid state; through the throttling device, the pressure of the refrigerant decreases and becomes a low-temperature and low-pressure mixed state. The mixed-state refrigerant enters the outdoor heat exchanger 24, absorbs the heat of the outside air, and evaporates into a gas state. Then, the gaseous refrigerant flows through the gas-liquid separator 22 and then enters the compressor 21, where it is compressed into a high-temperature and high-pressure gas state. Finally, the high-temperature and high-pressure refrigerant enters the indoor unit 10, releases heat to the indoor, cools and liquefies to complete the cycle.

[0064] That is to say, in the heating mode, the high-temperature and high-pressure gaseous refrigerant first undergoes forced convection heat transfer in the second convective heat exchanger 12 to become a high-temperature two-phase state, then enters the radiant heat exchanger 2 to perform radiant heat transfer with the indoor environment, and finally enters the first convective heat exchanger 11 to perform forced convection heat transfer to the subcooled state and flows into the outdoor unit 20. In this way, the serial connection of the second convective heat exchanger 12, the radiant heat exchanger 2, and the first convective heat exchanger 11 results in a smaller number of flow paths, so that the flow rate of the refrigerant in the heating flow path 4 is faster, thereby increasing the heat transfer coefficient and improving the heat transfer efficiency.

[0065] Therefore, the flow direction of the refrigerant in the cooling mode is opposite to that in the heating mode.

[0066] Therefore, in order to achieve the functions of the throttling device described above to control the flow rate of the refrigerant, the indoor unit 10 provided in this embodiment further includes an indoor throttle valve 5. Correspondingly, an outdoor throttle valve 25 may also be provided in the outdoor unit 20. When the indoor unit 10 is in the cooling mode, the indoor throttle valve 5 is located on the upstream side of the cooling flow path 3. And in the cooling mode, the main task of the indoor throttle valve 5 is to throttle the high-pressure liquid refrigerant from the outdoor heat exchanger 24 to a low pressure, so that it evaporates in the first convection heat exchanger 11 and the second convection heat exchanger 12, thereby absorbing the heat in the room. At this time, the opening degree of the indoor throttle valve 5 is usually small to control an appropriate amount of refrigerant flowing into the first convection heat exchanger 11 and the second convection heat exchanger 12, ensuring that the refrigerant can fully evaporate in the first convection heat exchanger 11 and the second convection heat exchanger 12 and preventing liquid refrigerant from entering the compressor, causing "liquid slugging". Moreover, at this time, the outdoor throttle valve 25 is in the fully open state to allow the refrigerant vapor to flow smoothly, facilitating the condensation process. Among them, the indoor throttle valve 5 is an electronic expansion valve.

[0067] It should be noted that liquid slugging is a common failure phenomenon that occurs in the compressor 21. When liquid refrigerant or excessive liquid droplets are sucked into the compressor 21, liquid slugging will be triggered.

[0068] When the indoor unit 10 is in the heating mode, the indoor throttle valve 5 is located on the downstream side of the heating flow path 4, and the indoor throttle valve 5 is in the fully open state to allow the refrigerant to flow smoothly. At this time, the outdoor throttle valve 25 will control the flow rate of the refrigerant throttled from the high-pressure state to the low-pressure state, so that the refrigerant evaporates in the outdoor heat exchanger 24, absorbing the heat in the outdoor air. Therefore, the opening degree of the outdoor throttle valve 25 will be adjusted according to the outdoor temperature and the indoor heat load demand.

[0069] It can be understood that when the indoor unit 10 provided in this embodiment is in the cooling mode, there may be situations where the indoor temperature is too low or too high; when the indoor unit 10 provided in this embodiment is in the heating mode, there may be situations where the indoor temperature is too high or too low. In order to keep the indoor temperature suitable in these situations, the indoor unit 10 provided in this embodiment further includes a blower 7, and the blower 7 is connected to the first convection heat exchanger 11 or the second convection heat exchanger 12. By adjusting the rotation speed of the blower 7, the indoor temperature can be adjusted assistively.

[0070] Taking the heating mode as an example, when the indoor heat load is large, that is, when the indoor temperature is low, the compressor 21 increases its frequency, and the speed of the blower 7 is adjusted to the maximum to increase the heat exchange capacity of the indoor unit 10, so as to achieve the purpose of rapid heating; when the indoor heat load is small, that is, when the indoor temperature is too high, the speed of the blower 7 is adjusted to zero, and at the same time the compressor 21 reduces its frequency. The indoor unit only uses radiation and natural convection for heating, creating a space thermal environment that conforms to human comfort, and can achieve low-noise and low-energy consumption operation. At the same time, the radiation heat exchange method can optimize the intermittency of the operation of the HVAC equipment 100.

[0071] That is to say, under the action of the blower 7, the HVAC equipment can be intermittently started and stopped during operation. In this way, unnecessary energy consumption can be reduced, and the HVAC equipment 100 can operate with low energy consumption.

[0072] In order to form the above-mentioned refrigeration flow path 3 and heating flow path 4, the indoor unit 10 provided in this embodiment further includes a regulating valve 6. By opening, closing the regulating valve 6 and conducting the internal flow path, the above-mentioned refrigeration flow path 3 and heating flow path 4 are formed. This embodiment provides three forms of the regulating valve 6, which will be specifically introduced below.

[0073] As Figure 1 、 Figure 4 and Figure 7 shown, in the first implementation manner, the regulating valve 6 can be a solenoid valve. When the indoor unit 10 is in the refrigeration mode, the solenoid valve is opened, and the refrigerant flows from the first convection heat exchanger 11 to the second convection heat exchanger 12 via the solenoid valve; when the indoor unit 10 is in the heating mode, the solenoid valve is closed, and the refrigerant does not flow through the solenoid valve.

[0074] Specifically, in the refrigeration mode, the flow direction of the refrigerant is: compressor 21 → four-way reversing valve 23 → outdoor heat exchanger 24 → outdoor throttle valve 25 → indoor throttle valve 5 → first convection heat exchanger 11 → solenoid valve → second convection heat exchanger 12 → four-way reversing valve 23 → gas-liquid separator 22 → compressor 21;

[0075] In the heating mode, the flow direction of the refrigerant is: compressor 21 → four-way reversing valve 23 → second convection heat exchanger 12 → radiation heat exchanger 2 → first convection heat exchanger 11 → indoor throttle valve 5 → outdoor throttle valve 25 → outdoor heat exchanger 24 → four-way reversing valve 23 → gas-liquid separator 22 → compressor 21.

[0076] As Figure 2 、 Figure 5 and Figure 8 shown, in the second implementation manner, the regulating valve 6 can be a check valve. When the indoor unit 10 is in the refrigeration mode, the check valve is opened, and the refrigerant flows from the first convection heat exchanger 11 to the second convection heat exchanger 12 via the check valve; when the indoor unit 10 is in the heating mode, the check valve is closed, and the refrigerant does not flow through the check valve.

[0077] Specifically, in the refrigeration mode, the refrigerant flow direction is: compressor 21 → four-way reversing valve 23 → outdoor heat exchanger 24 → outdoor throttle valve 25 → indoor throttle valve 5 → first convection heat exchanger 11 → check valve → second convection heat exchanger 12 → four-way reversing valve 23 → gas-liquid separator 22 → compressor 21;

[0078] In the heating mode, the refrigerant flow direction is: compressor 21 → four-way reversing valve 23 → second convection heat exchanger 12 → radiation heat exchanger 2 → first convection heat exchanger 11 → indoor throttle valve 5 → outdoor throttle valve 25 → outdoor heat exchanger 24 → four-way reversing valve 23 → gas-liquid separator 22 → compressor 21.

[0079] As Figure 3 、 Figure 6 and Figure 9 shown, in the third embodiment, the regulating valve 6 can be a reversing valve, the reversing valve has a first valve port 61, a second valve port 62, a third valve port 63 and a fourth valve port 64. When the indoor unit 10 is in the refrigeration mode, the first valve port 61 and the second valve port 62 are connected, the third valve port 63 and the fourth valve port 64 are connected, and the refrigerant flows from the first convection heat exchanger 11 through the first valve port 61 and the second valve port 62 to the second convection heat exchanger 12; when the indoor unit 10 is in the heating mode, the first valve port 61 and the fourth valve port 64 are connected, the second valve port 62 and the third valve port 63 are connected, and the refrigerant flows from the second convection heat exchanger 12 through the second valve port 62 and the third valve port 63 to the radiation heat exchanger 2, and the refrigerant flows from the radiation heat exchanger 2 through the fourth valve port 64 and the first valve port 61 to the first convection heat exchanger 11.

[0080] Specifically, in the refrigeration mode, the refrigerant flow direction is: compressor 21 → four-way reversing valve 23 → outdoor heat exchanger 24 → outdoor throttle valve 25 → indoor throttle valve 5 → first convection heat exchanger 11 → first valve port 61 → second valve port 62 → second convection heat exchanger 12 → four-way reversing valve 23 → gas-liquid separator 22 → compressor 21, that is, in the refrigeration mode, there is no refrigerant flow in the radiation heat exchanger 2;

[0081] In the heating mode, the refrigerant flow direction is: compressor 21 → four-way reversing valve 23 → second convection heat exchanger 12 → second valve port 62 → third valve port 63 → radiation heat exchanger 2 → fourth valve port 64 → first valve port 61 → first convection heat exchanger 11 → indoor throttle valve 5 → outdoor throttle valve 25 → outdoor heat exchanger 24 → four-way reversing valve 23 → gas-liquid separator 22 → compressor 21.

[0082] It is understandable that when the outdoor temperature is relatively low, frost may form on the outdoor unit 20. Therefore, it is necessary to defrost the frost on the outdoor unit 20. Generally, the defrosting mode is switched from the heating mode. In this embodiment, when the indoor unit 10 is in the defrosting mode, a defrosting flow path is formed. The defrosting flow path here can refer to the above-mentioned refrigeration flow path 3. The first convection heat exchanger 11 and the second convection heat exchanger 12 are sequentially arranged on the defrosting flow path along the refrigerant flow direction; when the indoor unit 10 is in the defrosting mode, there is no refrigerant flowing in the radiation heat exchanger 2. That is to say, when the indoor unit 10 is switched from the heating mode to the defrosting mode, there is still high-temperature and high-pressure refrigerant in the radiation heat exchanger 2 during the heating mode. Therefore, in the defrosting mode, the radiation heat exchanger 2 can still release heat to the room to a certain extent to avoid the indoor ambient temperature being relatively low during the defrosting mode.

[0083] This embodiment also provides a heating and ventilation equipment 100, which includes an outdoor unit 20 and the indoor unit 10 in the above-mentioned embodiment connected together. Among them, the structures of the indoor unit 10 and the outdoor unit 20 have been introduced in detail in the above-mentioned embodiment, and will not be elaborated here.

[0084] Of course, the heating and ventilation equipment 100 provided in this embodiment should also include an electronic control component, etc. Here, no specific restrictions are imposed on the modules included in the heating and ventilation equipment 100 provided in this embodiment.

[0085] It should be noted that the heating and ventilation equipment 100 provided in this embodiment can also be a multi-connected air-conditioning system. That is to say, there are multiple indoor units 10, and the multiple indoor units 10 are connected in parallel with each other. Among them, the refrigerant flow paths of each indoor unit 10 in the cooling mode and the heating mode can refer to the refrigerant flow paths in the above-mentioned embodiment. Here, the refrigerant flow path of the entire system will not be elaborated.

[0086] Since the heating and ventilation equipment 100 provided in this embodiment adopts the indoor unit 10 in the above-mentioned embodiment, the comfort of the heating and ventilation equipment 100 provided in this embodiment is relatively high and the system energy consumption is relatively low, so that the service performance of the heating and ventilation equipment 100 provided in this embodiment is relatively good.

[0087] 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 first countercurrent heat exchanger, a second countercurrent heat exchanger and a radiation heat exchanger; The indoor unit forms a cooling flow path when in cooling mode, and the first counter-flow heat exchanger and the second counter-flow heat exchanger are sequentially arranged on the cooling flow path along the flow direction of the refrigerant; The indoor unit forms a heating flow path in a heating mode, and the second counter-flow heat exchanger, the radiation heat exchanger, and the first counter-flow heat exchanger are sequentially arranged on the heating flow path along a flow direction of the refrigerant.

2. The indoor unit according to claim 1, characterized in that: Also includes a regulating valve; When the indoor unit is in the cooling mode, the regulating valve is opened, and the refrigerant flows from the first counter-flow heat exchanger to the second counter-flow heat exchanger via the regulating valve; When the indoor unit is in the heating mode, the regulating valve is closed, and the refrigerant does not flow through the regulating valve.

3. The indoor unit according to claim 2, characterized in that: The regulating valve is a solenoid valve or a one-way valve.

4. The indoor unit according to claim 1, characterized in that: It also includes a regulating valve, which is a reversing valve; When the indoor unit is in the cooling mode, the refrigerant flows from the first counter-flow heat exchanger to the second counter-flow heat exchanger via the reversing valve; When the indoor unit is in the heating mode, the refrigerant flows from the second counter-flow heat exchanger to the radiation heat exchanger via the reversing valve, and flows from the radiation heat exchanger to the first counter-flow heat exchanger via the reversing valve.

5. The indoor unit according to claim 4, characterized in that: The indoor unit forms a defrost flow path when in defrost mode, and the first counter-flow heat exchanger and the second counter-flow heat exchanger are sequentially arranged on the defrost flow path along the flow direction of the refrigerant; When the indoor unit is in the defrost mode, no refrigerant flows in the radiation heat exchanger.

6. The indoor unit according to any one of claims 1 to 5, characterized in that: It also includes fans; The fan is connected to the first countercurrent heat exchanger; or, The fan is connected to the second countercurrent heat exchanger.

7. The indoor unit according to any one of claims 1 to 5, characterized in that: Also included is an indoor throttle valve; When the indoor unit is in the cooling mode, the indoor throttle valve is located on the upstream side of the cooling flow path; When the indoor unit is in the heating mode, the indoor throttle valve is located on the downstream side of the heating flow path, and the indoor throttle valve is in a fully open state.

8. The indoor unit according to claim 7, characterized in that: The indoor throttle valve is an electronic expansion valve.

9. The indoor unit according to any one of claims 1 to 5 and 8, characterized in that: The first counter-flow heat exchanger and the second counter-flow heat exchanger are both shell and tube heat exchangers; and / or, The radiation heat exchanger is a radiation heat exchange plate.

10. A HVAC equipment, characterized in that: It comprises an outdoor unit and an indoor unit as claimed in any one of claims 1 to 9 connected together.

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