Two-pipe heat recovery air conditioning system

Abstract

This application relates to the field of air conditioning technology and discloses a two-pipe heat recovery air conditioning system, including: an air conditioning unit, a first circulation loop, a second circulation loop, and a circulating water pump. The air conditioning unit includes an outdoor heat exchanger, at least one first indoor heat exchanger, and at least one second indoor heat exchanger, with the first and second indoor heat exchangers located in different areas. A first throttling device is provided on one side of the first medium channel of the first indoor heat exchanger, and a second throttling device is provided on one side of the first medium channel of the second indoor heat exchanger. Multiple functional modes can be achieved by controlling the states of the circulating water pump, the first throttling device, and the second throttling device. Thus, a simple and easy-to-control air conditioning system can meet the cooling or heating needs of different areas.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, for example to a two-pipe heat recovery air conditioning system. Background Technology

[0002] With the acceleration of urbanization in my country, large public buildings have gradually become a symbol of urbanization, and their rapid development has led to an increasing demand for and application of HVAC systems. In actual public buildings, the heating and cooling needs of different areas often differ: the heating and cooling needs of the outer areas are often related to outdoor weather conditions, while the inner areas are primarily for cooling. Therefore, the following pattern emerges: in summer, both the inner and outer areas require cooling; in winter, the outer areas require heating, while the inner areas require cooling; and during transitional seasons, heating or cooling needs to be provided based on outdoor weather conditions and the actual needs of both the inner and outer areas.

[0003] The related technology discloses a two-pipe heat recovery multi-split air conditioning system. The outdoor unit includes a main circulation path and a vapor injection enthalpy-increasing circulation path. The main circulation path includes a vapor injection enthalpy-increasing compressor, a reversing device, and an outdoor heat exchanger connected by pipes, with its two ends connected to the inlet and outlet of a refrigerant distribution device via refrigerant outlet and refrigerant inlet pipes, respectively. The vapor injection enthalpy-increasing circulation path includes a flash evaporator and an outdoor throttling device. The inlet of the flash evaporator is connected to the refrigerant inlet pipe via a first pipe, the gas-side outlet is connected to the vapor port of the vapor injection enthalpy-increasing compressor via a second pipe, and the liquid-side outlet is connected to the input end of the outdoor heat exchanger via a third pipe. The outdoor throttling device is located on the third pipe. This system can meet the heating and cooling needs of different areas.

[0004] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] This system has multiple refrigerant lines, requiring a high refrigerant charge. The system is complex, has numerous switching valves, and is difficult to control. Furthermore, switching between modes, such as heating and cooling, requires filling the hot water lines with chilled water, leading to energy mixing and reduced efficiency. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a two-pipe heat recovery air conditioning system to solve the problem of how to meet the cooling or heating needs of different areas with a simple and easy-to-control air conditioning system.

[0008] In some embodiments, the two-pipe heat recovery air conditioning system includes:

[0009] An air conditioning unit includes an outdoor heat exchanger, at least one first indoor heat exchanger, and at least one second indoor heat exchanger, wherein the first indoor heat exchanger and the second indoor heat exchanger are located in different areas; and the first indoor heat exchanger is a dual-medium heat exchanger, while the second indoor heat exchanger and the outdoor heat exchanger are three-medium heat exchangers.

[0010] In the first circulation loop, the first medium channel of the outdoor heat exchanger, the first medium channel of the first indoor heat exchanger, and the first medium channel of the second indoor heat exchanger are connected in the first circulation loop; and the first medium channel of the first indoor heat exchanger and the first medium channel of the second indoor heat exchanger are connected in parallel, while the first medium channel of the outdoor heat exchanger and the first medium channel of the first indoor heat exchanger are connected in series.

[0011] The second circulation loop is provided with a second medium channel of the outdoor heat exchanger and a second medium channel of the second indoor heat exchanger connected in series and in the second circulation loop; and the second circulation loop is provided with a first regulating valve for regulating the flow rate of the second circulation loop.

[0012] A circulating water pump is installed in the second circulation loop;

[0013] The first indoor heat exchanger has a first throttling device on one side of the first medium channel, and the second indoor heat exchanger has a second throttling device on one side of the first medium channel, thereby enabling multiple functional modes by controlling the states of the circulating water pump, the first throttling device, and the second throttling device.

[0014] Optionally, the third medium channel of the outdoor heat exchanger is a first air channel, through which air flows to exchange heat with the first medium channel and / or the second medium channel of the outdoor heat exchanger by means of an outdoor fan;

[0015] The other medium channel of the first indoor heat exchanger is the second air channel. Air is made to flow through the second air channel by the first indoor fan to exchange heat with the first medium channel of the first indoor heat exchanger.

[0016] The third medium channel of the second indoor heat exchanger is a third air channel. Air is flowed through the third air channel by the second indoor fan to exchange heat with the first medium channel and / or the second medium channel of the second indoor heat exchanger.

[0017] Optionally, the air conditioning unit further includes:

[0018] The third indoor heat exchanger is a dual-medium heat exchanger; the second medium channel of the third indoor heat exchanger is connected to the second circulation loop and is in parallel with the second medium channel of the second indoor heat exchanger.

[0019] The other medium channel of the third indoor heat exchanger is the fourth air channel. A third indoor fan is provided on one side of the third indoor heat exchanger. Indoor air passes through the fourth air channel and exchanges heat with the second medium channel of the third indoor heat exchanger to form hot air or cold air.

[0020] A second regulating valve is provided on the inflow side of the second medium channel of the third indoor heat exchanger.

[0021] Optionally, the second loop is further provided with:

[0022] A safety valve is used to release pressure when the pressure in the second circulation loop exceeds a set pressure value; and / or,

[0023] A filter for removing impurities from the circulating medium flowing through the second circulation loop; and / or,

[0024] An expansion tank is used to provide variable volume space for volume changes caused by temperature variations in the circulating medium in the second circulation loop; and / or,

[0025] A buffer tank is used to store part of the circulating medium in the second circulation loop and to provide variable volume space for volume changes caused by temperature variations in the circulating medium.

[0026] Optionally, the circulating medium in the first circulation loop includes refrigerant; and / or,

[0027] The circulating medium in the second circulation loop includes water or antifreeze.

[0028] Optionally, the air conditioning system has a full-zone heating mode, which corresponds to the heating cycle of the first circulation loop, wherein both the first throttling device and the second throttling device are turned on, and the circulating water pump is turned off.

[0029] Optionally, the air conditioning system has a full-zone cooling mode, which corresponds to the first circulation loop operating a refrigeration cycle, wherein both the first throttling device and the second throttling device are turned on, and the circulating water pump is turned off.

[0030] Optionally, the air conditioning system has a first zone cooling / heating mode, which corresponds to the first circulation loop operating a cooling cycle. The first throttling device is turned on, the second throttling device is turned off, and the circulating water pump is turned on, thereby providing cooling through the first indoor heat exchanger and heating through the second indoor heat exchanger.

[0031] Optionally, the air conditioning system has a second zone cooling / heating mode, which corresponds to the heating cycle of the first circulation loop. The first throttling device is turned on, the second throttling device is turned off, and the circulating water pump is turned on, thereby providing heating through the first indoor heat exchanger and cooling through the second indoor heat exchanger.

[0032] Optionally, the circulating medium in the first circulation loop (200) includes refrigerant; and / or,

[0033] The circulating medium in the second circulation loop (300) includes water or antifreeze.

[0034] The two-pipe heat recovery air conditioning system provided in this embodiment can achieve the following technical effects:

[0035] Multiple functional modes are achieved by controlling the circulating water pump, the first throttling device, and the second throttling device, simultaneously meeting the cooling or heating needs of different areas. This air conditioning system features a simple structure, low refrigerant charge, fewer valves, easy control, and high energy efficiency, requiring a low energy grade for operation. Furthermore, no energy mixing occurs when switching between multiple modes, effectively improving system energy efficiency.

[0036] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0037] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0038] Figure 1 This is a schematic diagram of the structure of a two-pipe heat recovery air conditioning system provided in an embodiment of this disclosure;

[0039] Figure 2 This is a schematic diagram of the whole-area heating mode provided in the embodiments of this disclosure;

[0040] Figure 3 This is a schematic diagram of the full-area cooling mode provided in the embodiments of this disclosure;

[0041] Figure 4 This is a schematic diagram of the first zone cooling / heating mode provided in an embodiment of this disclosure;

[0042] Figure 5 This is a schematic diagram of the second zone cooling / heating mode provided in an embodiment of this disclosure;

[0043] Figure 6 This is a schematic diagram of multiple third indoor heat exchangers connected in parallel according to an embodiment of this disclosure.

[0044] Figure label:

[0045] 1: Compressor; 2: Four-way reversing valve; 3: First indoor heat exchanger; 30: First throttling device; 4: Second indoor heat exchanger; 40: Second throttling device; 5: Outdoor heat exchanger; 6: Circulating water pump; 7: First regulating valve; 8: Third indoor heat exchanger; 9: Second regulating valve; 101: First medium passage; 102: Second medium passage; 103: First air passage; 104: Second air passage; 105: Third air passage; 106: Fourth air passage; 200: First circulation loop; 300: Second circulation loop. Detailed Implementation

[0046] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0047] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0048] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0049] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0050] Unless otherwise stated, the term "multiple" means two or more.

[0051] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0052] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0053] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0054] Combination Figure 1-6 As shown, this disclosure provides a two-pipe heat recovery air conditioning system, including an air conditioning unit, a first circulation loop 200, a second circulation loop 300, and a circulating water pump 6. The air conditioning unit includes an outdoor heat exchanger 5, at least one first indoor heat exchanger 3, and at least one second indoor heat exchanger 4, with the first indoor heat exchanger 3 and the second indoor heat exchanger 4 located in different areas. Furthermore, the first indoor heat exchanger 3 is a dual-medium heat exchanger, and the second indoor heat exchanger 4 and the outdoor heat exchanger 5 are three-medium heat exchangers. The first medium channel 101 of the outdoor heat exchanger 5, the first medium channel 101 of the first indoor heat exchanger 3, and the first medium channel 101 of the second indoor heat exchanger 4 are connected to the first circulation loop 200. The first medium channel 101 of the first indoor heat exchanger 3 and the first medium channel 101 of the second indoor heat exchanger 4 are connected in parallel. The outdoor heat exchanger 5 has a first medium channel 101 connected in series with the first medium channel 101 of the first indoor heat exchanger 3; the outdoor heat exchanger 5 has a second medium channel 102 connected in series with the second indoor heat exchanger 4 and connected to the second circulation loop 300; the circulating water pump 6 is installed in the second circulation loop 300; wherein, a first throttling device 30 is provided on one side of the first medium channel 101 of the first indoor heat exchanger 3, and a second throttling device 40 is provided on one side of the first medium channel 101 of the second indoor heat exchanger 4, so that multiple functional modes can be realized by controlling the state of the circulating water pump 6, the first throttling device 30 and the second throttling device 40.

[0055] The two-pipe heat recovery air conditioning system provided in this embodiment achieves multiple functional modes by controlling the states of the circulating water pump 6, the first throttling device 30, and the second throttling device 40, simultaneously meeting the cooling or heating needs of different areas. Furthermore, this two-pipe heat recovery air conditioning system has a simple structure, requires a small refrigerant charge, has fewer valves, is easier to control, and has high energy efficiency, requiring a lower energy grade for operation. Moreover, no energy mixing occurs when switching between multiple modes, effectively improving system energy efficiency.

[0056] Optionally, such as Figure 1 As shown, the third medium channel of the outdoor heat exchanger 5 is the first air channel 103, through which air flows to exchange heat with the first medium channel 101 and / or the second medium channel 102 of the outdoor heat exchanger 5 via an outdoor fan; the other medium channel of the first indoor heat exchanger 3 is the second air channel 104, through which air flows to exchange heat with the first medium channel 101 of the first indoor heat exchanger 3 via a first indoor fan; the third medium channel of the second indoor heat exchanger 4 is the third air channel 105, through which air flows to exchange heat with the first medium channel 101 and / or the second medium channel 102 of the second indoor heat exchanger 4 via a second indoor fan.

[0057] In this embodiment, when the outdoor fan starts, outdoor air flows through the first air channel 103, thereby exchanging heat with the first medium channel 101 and / or the second medium channel 102 of the outdoor heat exchanger 5. When the first indoor fan starts, air in the area where the first indoor heat exchanger 3 is located flows through the second air channel 104, thereby exchanging heat with the first medium channel 101 of the first indoor heat exchanger 3. When the second indoor fan starts, air in the area where the second indoor heat exchanger 4 is located flows through the third air channel 105, thereby exchanging heat with the first medium channel 101 and / or the second medium channel 102 of the second indoor heat exchanger 4.

[0058] Optionally, the circulating medium in the first circulation loop 200 includes refrigerant. In the two-pipe heat recovery air conditioning system provided in this embodiment, the first circulation loop 200 is further provided with a compressor 1 and a four-way reversing valve 2. The compressor 1 is used to drive the flow of refrigerant in the first circulation loop 200, and the four-way reversing valve 2 is used to switch the flow direction of refrigerant in the first circulation loop 200, thereby realizing the first circulation loop 200 to operate in a heating cycle or a cooling cycle. The first throttling device 30 and the second throttling device 40 are both expansion valves, which are used to throttle and reduce the pressure of the refrigerant. Wherein, when the first circulation loop 200 operates in a heating cycle, the flow direction of its refrigerant is compressor 1, four-way reversing valve 2, first indoor heat exchanger 3 and second indoor heat exchanger 4, outdoor heat exchanger 5 and compressor 1. When the first circulation loop 200 operates in a cooling cycle, the flow direction of its refrigerant is compressor 1, four-way reversing valve 2, outdoor heat exchanger 5, first indoor heat exchanger 3 and second indoor heat exchanger 4, and compressor 1.

[0059] Optionally, the first circulation loop 200 is also provided with an oil separator, and / or a gas-liquid separator, and / or a recooler.

[0060] For example, in a two-pipe heat recovery air conditioning system, a compressor 1, a four-way reversing valve 2, an outdoor heat exchanger 5, a first indoor heat exchanger 3, a second indoor heat exchanger 4, an oil separator, a gas-liquid separator, and a recooler are used to form a first circulation loop 200.

[0061] Optionally, the circulating medium in the second circulation loop 300 includes water or antifreeze. Water and antifreeze have excellent cooling capacity.

[0062] In this embodiment, the water or antifreeze circulates in the loop 300. When the second medium flows through the outdoor heat exchanger 5 and the circulating water pump 6 is turned on, the water or antifreeze exchanges heat with the first medium channel 101 of the outdoor heat exchanger 5 in the second medium channel 102. The water or antifreeze carries the heat or cold obtained from the outdoor heat exchanger 5 into the second medium channel 102 of the second indoor heat exchanger 4, at which time it can supply heat or cold to the area corresponding to the second indoor heat exchanger 4.

[0063] Optionally, the second circulation loop 300 is further provided with a safety valve, which is used to open and release pressure when the pressure in the second circulation loop 300 exceeds a set pressure value; and / or, a filter is also provided to remove impurities from the circulating medium flowing through the second circulation loop 300; and / or, an expansion tank is also provided to provide variable volume space for volume changes caused by temperature changes in the circulating medium in the second circulation loop 300; and / or, a buffer tank is also provided to store a portion of the circulating medium in the second circulation loop 300 and to provide variable volume space for volume changes caused by temperature changes in the circulating medium.

[0064] For example, in a two-pipe heat recovery air conditioning system, the second medium channel 102 of the outdoor heat exchanger 5, the second medium channel 102 of the second indoor heat exchanger 4, the circulating water pump 6, the safety valve, the filter, the expansion tank and the buffer tank together constitute the second circulation loop 300.

[0065] Optionally, the second circulation loop 300 is provided with a first regulating valve 7, which is used to regulate the flow rate of the second circulation loop 300.

[0066] In this embodiment, when the circulating water pump 6 is turned on, the flow rate of the second circulation loop 300 can be adjusted by controlling the opening of the first regulating valve 7, thereby controlling the heat supply or cooling capacity of the second medium channel 102 of the second indoor heat exchanger 4.

[0067] Optionally, such as Figure 2 As shown, the two-pipe heat recovery air conditioning system has a full-zone heating mode. The full-zone heating mode corresponds to the operation of the heating cycle in the first circulation loop 200, with both the first throttling device 30 and the second throttling device 40 open, and the circulating water pump 6 closed.

[0068] In this embodiment, when both the areas corresponding to the first indoor heat exchanger 3 and the second indoor heat exchanger 4 have heating needs, the two-pipe heat recovery air conditioning system operates in full-zone heating mode. In full-zone heating mode, the second circulation loop 300 is in a blocked state, the first circulation loop 200 operates in heating cycle, and the first medium channel 101 of the first indoor heat exchanger 3 and the first medium channel 101 of the second indoor heat exchanger 4 contain high-temperature refrigerant. Both the first indoor fan and the second indoor fan are started, thereby supplying heated air to the corresponding areas.

[0069] Optionally, such as Figure 3 As shown, the two-pipe heat recovery air conditioning system has a full-zone cooling mode. The full-zone cooling mode corresponds to the first circulation loop 200 operating the refrigeration cycle, with both the first throttling device 30 and the second throttling device 40 open, and the circulating water pump 6 closed.

[0070] In this embodiment, when both the areas corresponding to the first indoor heat exchanger 3 and the second indoor heat exchanger 4 have cooling needs, the two-pipe heat recovery air conditioning system operates in full-zone cooling mode. In full-zone cooling mode, the second circulation loop 300 is in a blocked state, the first circulation loop 200 operates a refrigeration cycle, and the first medium channel 101 of the first indoor heat exchanger 3 and the first medium channel 101 of the second indoor heat exchanger 4 contain low-temperature refrigerant. Both the first indoor fan and the second indoor fan are started, thereby supplying cool air to the corresponding areas.

[0071] Optionally, such as Figure 4As shown, the two-pipe heat recovery air conditioning system has a first zone cooling / heating mode. The first zone cooling / heating mode corresponds to the first circulation loop 200 running a cooling cycle. The first throttling device 30 is turned on, the second throttling device 40 is turned off, and the circulating water pump 6 is turned on, thereby providing cooling through the first indoor heat exchanger 3 and heating through the second indoor heat exchanger 4.

[0072] In this embodiment, when the area corresponding to the first indoor heat exchanger 3 has a cooling demand and the area corresponding to the second indoor heat exchanger 4 has a heating demand, the two-pipe heat recovery air conditioning system operates in the first zone cooling / heating mode. In the first zone cooling / heating mode, the second circulation loop 300 is in circulation, the first circulation loop 200 operates in a cooling cycle, and the first medium channel 101 of the second indoor heat exchanger 4 is blocked. The first medium channel 101 of the outdoor heat exchanger 5 contains high-temperature refrigerant, and the first medium channel 101 of the first indoor heat exchanger 3 contains low-temperature refrigerant. Water or antifreeze in the second medium channel 102 of the outdoor heat exchanger 5 exchanges heat with the high-temperature refrigerant. When water or antifreeze flows through the second medium channel 102 of the second indoor heat exchanger 4, under the action of the second indoor fan, air passes through the third air channel 105 and exchanges heat with the second medium channel 102 of the second indoor heat exchanger 4, thereby supplying hot air to the corresponding area. Simultaneously, under the action of the first indoor fan, air passes through the second air channel 104 and exchanges heat with the first medium channel 101 of the first indoor heat exchanger 3, thereby supplying cool air to the corresponding area. The outdoor fan turns on or off according to the system's heat balance. For example, if there is less heat at the first medium channel 101 of the outdoor heat exchanger 5, the outdoor fan turns off, effectively reducing the heat exchange between outdoor air and the first medium channel 101 and the second medium channel 102 of the outdoor heat exchanger 5, ensuring the heat exchange between the first medium channel 101 and the second medium channel 102 of the outdoor heat exchanger 5. If there is more heat at the first medium channel 101 of the outdoor heat exchanger 5, the outdoor fan turns on, achieving energy balance within the system and ensuring the heat exchange effect of the second indoor heat exchanger 4.

[0073] Optionally, such as Figure 5 As shown, the two-pipe heat recovery air conditioning system has a second zone cooling / heating mode. The second zone cooling / heating mode corresponds to the first circulation loop 200 operating in heating cycle. The first throttling device 30 is turned on, the second throttling device 40 is turned off, and the circulating water pump 6 is turned on, so that heating is provided through the first indoor heat exchanger 3 and cooling is provided through the second indoor heat exchanger 4.

[0074] In this embodiment, when the area corresponding to the first indoor heat exchanger 3 has heating demand and the area corresponding to the second indoor heat exchanger 4 has cooling demand, the two-pipe heat recovery air conditioning system operates in the second zone cooling / heating mode. In the second zone cooling / heating mode, the second circulation loop 300 is in circulation, the first circulation loop 200 operates in heating circulation, and the first medium channel 101 of the second indoor heat exchanger 4 is blocked. The first medium channel 101 of the outdoor heat exchanger 5 contains low-temperature refrigerant, and the first medium channel 101 of the first indoor heat exchanger 3 contains high-temperature refrigerant. Water or antifreeze in the second medium channel 102 of the outdoor heat exchanger 5 exchanges heat with the low-temperature refrigerant. When water or antifreeze flows through the second medium channel 102 of the second indoor heat exchanger 4, under the action of the second indoor fan, air passes through the third air channel 105 and exchanges heat with the second medium channel 102 of the second indoor heat exchanger 4, thereby supplying cold air to the corresponding area. At the same time, under the action of the first indoor fan, the air exchanges heat with the first medium channel 101 of the first indoor heat exchanger 3 through the second air channel 104, thereby supplying heating air to the corresponding area.

[0075] Optionally, such as Figure 6 As shown, a third indoor heat exchanger 8 is also provided on the second circulation loop 300. The third indoor heat exchanger 8 is a dual-medium heat exchanger, with its first medium channel 101 connected to the second circulation loop 300 and in parallel with the second medium channel 102 of the second indoor heat exchanger 4. The other medium channel of the third indoor heat exchanger 8 is a fourth air channel 106, and a third indoor fan is provided on one side of the third indoor heat exchanger 8. Under the action of the third indoor fan, indoor air passes through the fourth air channel 106 and exchanges heat with the second medium channel 102 of the third indoor heat exchanger 8 to form hot air or cold air. A second regulating valve 9 is provided on the inflow side of the second medium channel 102 of the third indoor heat exchanger 8, and the flow rate of the circulating medium in the second circulation loop 300 in the second medium channel 102 of the third indoor heat exchanger 8 is regulated by the second regulating valve 9.

[0076] In this embodiment, the second indoor heat exchanger 4 and the third indoor heat exchanger 8 are located in the same or different areas. (1) When the two-pipe heat recovery air conditioning system operates in the first zone cooling / heating mode, the second indoor heat exchanger 4 and the third indoor heat exchanger 8 respectively supply heating to the corresponding areas, and the heating demand of different areas is met by adjusting the opening degree of the first regulating valve 7 and the second regulating valve 9 or the air volume of the second indoor fan and the third indoor fan. When the two-pipe heat recovery air conditioning system operates in the second zone cooling / heating mode, the second indoor heat exchanger 4 and the third indoor heat exchanger 8 respectively supply cooling to the corresponding areas, and the cooling demand of different areas is met by adjusting the opening degree of the first regulating valve 7 and the second regulating valve 9 or the air volume of the second indoor fan and the third indoor fan.

[0077] (2) When the two-pipe heat recovery air conditioning system operates in full-zone heating / cooling mode, the third indoor heat exchanger 8 supplies cooling / heating to the corresponding zones respectively, and meets the cooling / heating needs of the corresponding zones by adjusting the opening of the second regulating valve 9 or the air volume of the third indoor fan. In full-zone heating / cooling mode, the difference from the above embodiment is that the second circulation loop 300 is in circulation state. The water or antifreeze in the second medium channel 102 of the outdoor heat exchanger 5 exchanges heat with the low-temperature / high-temperature refrigerant. When the water or antifreeze flows through the second medium channel 102 of the third indoor heat exchanger 8, under the action of the third indoor fan, the air passes through the fourth air channel 106 and exchanges heat with the second medium channel 102 of the third indoor heat exchanger 8, thereby supplying cooling / heating air to the corresponding zones.

[0078] (3) When the two-pipe heat recovery air conditioning system operates in the full-zone heating / cooling mode, the third indoor heat exchanger 8 supplies heating / cooling to the corresponding zones respectively, and meets the heating / cooling needs of the corresponding zones by adjusting the opening of the second regulating valve 9 or the air volume of the third indoor fan. In the full-zone heating / cooling mode, the difference from the above embodiment is that the second circulation loop 300 is in circulation. Under the action of the heat pump circulation, when the generated heat passes through the first medium channel 101 of the second indoor heat exchanger 4, on the one hand, under the action of the fan, it is transferred to the air in the third air heat exchange channel 105 to form hot air to provide heating / cooling for the indoor rooms. On the other hand, the water or antifreeze in the second medium channel 102 of the second indoor heat exchanger 4 exchanges heat with the high-temperature / low-temperature refrigerant in the first medium channel 101. When the water or antifreeze flows through the second medium channel 102 of the third indoor heat exchanger 8, under the action of the third indoor fan, the air passes through the fourth air channel 106 and exchanges heat with the second medium channel 102 of the third indoor heat exchanger 8, thereby supplying heating / cooling air to the corresponding zones.

[0079] Optionally, in the case of a two-pipe heat recovery air conditioning system having multiple first indoor heat exchangers 3, the first medium channels 101 of the multiple first indoor heat exchangers 3 are connected in parallel and connected to the first circulation loop 200.

[0080] Optionally, in the case of multiple second indoor heat exchangers 4, the second medium channels 102 of the multiple second indoor heat exchangers 4 are connected in parallel and connected to the second circulation loop 300. Each second indoor heat exchanger 4 has a first regulating valve 7 on the inflow side of its second medium channel 102, thereby adjusting the heating or cooling capacity of the corresponding second indoor heat exchanger 4 by controlling the opening degree of each first regulating valve 7 or the airflow of the second indoor fan. In this way, the two-pipe heat recovery air conditioning system can effectively regulate the cooling or heating capacity of different areas while meeting the cooling or heating needs of different areas.

[0081] For example, a two-pipe heat recovery air conditioning system has two first indoor heat exchangers 3 and two second indoor heat exchangers 4, wherein the two first indoor heat exchangers 3 are located in zone one and zone two, respectively, and the two second indoor heat exchangers 4 are located in zone three and zone four, respectively. When zone one and zone two have cooling demand, zone three has low-speed heating demand, and zone four has rapid heating demand, the two-pipe heat recovery air conditioning system operates in a first zone cooling / heating mode. At this time, the two first indoor heat exchangers 3 supply cooling air to the corresponding zone one and zone two, respectively, and the two second indoor heat exchangers 4 supply heating air to the corresponding zone three and zone four, respectively. Furthermore, the opening of the first regulating valve 7 corresponding to the second indoor heat exchanger 4 in zone three is adjusted to 1 / 4, and the opening of the first regulating valve 7 corresponding to the second indoor heat exchanger 4 in zone four is adjusted to fully open. In this way, the flow rate of water or refrigerant in the second medium channel 102 of the second indoor heat exchanger 4 in Zone 3 is relatively small, which meets the low-speed heating needs of Zone 3; while the flow rate of water or refrigerant in the second medium channel 102 of the second indoor heat exchanger 4 in Zone 4 is relatively large, which meets the rapid heating needs of Zone 3.

[0082] As another example, a two-pipe heat recovery air conditioning system has two first indoor heat exchangers 3 and two second indoor heat exchangers 4, wherein the two first indoor heat exchangers 3 are located in zone one and zone two, respectively, and the two second indoor heat exchangers 4 are located in zone three and zone four, respectively. When zone one and zone two have heating demand, zone three has low-speed cooling demand, and zone four has fast cooling demand, the two-pipe heat recovery air conditioning system operates in a second zone cooling / heating mode. At this time, the two first indoor heat exchangers 3 supply warm air to the corresponding zone one and zone two, respectively, and the two second indoor heat exchangers 4 supply cool air to the corresponding zone three and zone four, respectively. Furthermore, the power of the first fan corresponding to the second indoor heat exchanger 4 in zone three is adjusted to 1 / 4, and the power of the first fan corresponding to the second indoor heat exchanger 4 in zone four is adjusted to the maximum. In this way, the air volume of the third air passage 105 of the second indoor heat exchanger 4 in Zone 3 is relatively small, which meets the low-speed cooling demand of Zone 3; while the air volume of the third air passage 105 of the second indoor heat exchanger 4 in Zone 4 is relatively large, which meets the rapid cooling demand of Zone 3.

[0083] The foregoing description and accompanying drawings fully illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included or substituted for parts and features of other embodiments. Embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A two-pipe heat recovery air conditioning system, characterized in that, include: An air conditioning unit includes an outdoor heat exchanger (5), at least one first indoor heat exchanger (3), and at least one second indoor heat exchanger (4), wherein the first indoor heat exchanger (3) and the second indoor heat exchanger (4) are located in different areas; and the first indoor heat exchanger (3) is a dual-medium heat exchanger, and the second indoor heat exchanger (4) and the outdoor heat exchanger (5) are three-medium heat exchangers. The first circulation loop (200) is connected to the first medium channel (101) of the outdoor heat exchanger (5), the first medium channel (101) of the first indoor heat exchanger (3), and the first medium channel (101) of the second indoor heat exchanger (4); and the first medium channel (101) of the first indoor heat exchanger (3) and the first medium channel (101) of the second indoor heat exchanger (4) are connected in parallel, and the first medium channel (101) of the outdoor heat exchanger (5) is connected in series with the first medium channel (101) of the first indoor heat exchanger (3). The second circulation loop (300) is connected in series with the second medium channel (102) of the outdoor heat exchanger (5) and the second medium channel (102) of the second indoor heat exchanger (4). The second circulation loop (300) is provided with a first regulating valve (7) for regulating the flow rate of the second circulation loop (300). The circulation medium of the second circulation loop (300) includes water or antifreeze. A circulating water pump (6) is installed in the second circulation loop (300); Among them, a first throttling device (30) is provided on one side of the first medium channel (101) of the first indoor heat exchanger (3), and a second throttling device (40) is provided on one side of the first medium channel (101) of the second indoor heat exchanger (4), thereby realizing multiple functional modes by controlling the state of the circulating water pump (6), the first throttling device (30) and the second throttling device (40); The air conditioning system has a first zone cooling / heating mode, which corresponds to the first circulation loop (200) running a cooling cycle. The first throttling device (30) is turned on, the second throttling device (40) is turned off, and the circulating water pump (6) is turned on, thereby providing cooling through the first indoor heat exchanger (3) and heating through the second indoor heat exchanger (4).

2. The two-pipe heat recovery air conditioning system according to claim 1, characterized in that, The third medium channel of the outdoor heat exchanger (5) is the first air channel (103). An outdoor fan makes air flow through the first air channel (103) to exchange heat with the first medium channel (101) and / or the second medium channel (102) of the outdoor heat exchanger (5). Another medium channel of the first indoor heat exchanger (3) is the second air channel (104). Air is made to flow through the second air channel (104) by the first indoor fan to exchange heat with the first medium channel (101) of the first indoor heat exchanger (3). The third medium channel of the second indoor heat exchanger (4) is a third air channel (105). Air is made to flow through the third air channel (105) by the second indoor fan to exchange heat with the first medium channel (101) and / or the second medium channel (102) of the second indoor heat exchanger (4).

3. The two-pipe heat recovery air conditioning system according to claim 1 or 2, characterized in that, The air conditioning unit also includes: The third indoor heat exchanger (8) is a dual-medium heat exchanger; the second medium channel (102) of the third indoor heat exchanger (8) is connected to the second circulation loop (300) and is in parallel with the second medium channel (102) of the second indoor heat exchanger (4); The other medium channel of the third indoor heat exchanger (8) is the fourth air channel (106). A third indoor fan is provided on one side of the third indoor heat exchanger (8). Indoor air exchanges heat with the second medium channel (102) of the third indoor heat exchanger (8) through the fourth air channel (106) to form hot air or cold air. A second regulating valve (9) is provided on the inflow side of the second medium channel (102) of the third indoor heat exchanger (8).

4. The two-pipe heat recovery air conditioning system according to claim 1 or 2, characterized in that, The second loop (300) is also provided with: A safety valve is configured to open and release pressure when the pressure in the second circulation loop (300) exceeds a set pressure value; and / or, A filter is used to remove impurities from the circulating medium flowing through the second circulation loop (300); and / or, An expansion tank is used to provide variable volume space for volume changes caused by temperature variations in the circulating medium in the second circulation loop (300); and / or, The buffer tank is used to store part of the circulating medium of the second circulation loop (300) and to provide variable volume space for volume changes caused by temperature changes of the circulating medium.

5. The two-pipe heat recovery air conditioning system according to claim 1 or 2, characterized in that, The circulating medium in the first circulation loop (200) includes refrigerant.

6. The two-pipe heat recovery air conditioning system according to claim 1 or 2, characterized in that, The air conditioning system has a full-zone heating mode, which corresponds to the heating cycle of the first circulation loop (200). The first throttling device (30) and the second throttling device (40) are both turned on, and the circulating water pump (6) is turned off.

7. The two-pipe heat recovery air conditioning system according to claim 1 or 2, characterized in that, The air conditioning system has a full-zone cooling mode, which corresponds to the first circulation loop (200) running a refrigeration cycle. The first throttling device (30) and the second throttling device (40) are both turned on, and the circulating water pump (6) is turned off.

8. The two-pipe heat recovery air conditioning system according to claim 1 or 2, characterized in that, The air conditioning system has a second zone cooling / heating mode, which corresponds to the first circulation loop (200) operating in a heating cycle. The first throttling device (30) is turned on, the second throttling device (40) is turned off, and the circulating water pump (6) is turned on, thereby providing heat through the first indoor heat exchanger (3) and cooling through the second indoor heat exchanger (4).

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