Heat pump units, air conditioners and control methods

Abstract

This disclosure provides a heat pump unit, an air conditioner, and a control method. The heat pump unit has a first heat exchange path and a second heat exchange path connected in parallel. An ejector, a first ejector branch, a second ejector branch, and a third ejector branch are added to the heat pump unit. When the heat pump unit meets the ejector start-up conditions, both the second and third control valves can be controlled to be in the open state, thereby ensuring that both the first and second ejector branches are in a conductive state. Since the third ejector branch, connected to the ejector, is connected to the first and / or second refrigerant inlets of the evaporator-condenser, the refrigerant in the evaporator-condenser can be introduced into the heating circulation path of the heat pump unit without the need for an additional refrigerant pump. This improves the heating efficiency of the heat pump unit and enhances the user experience while maintaining low cost and without negatively impacting the compressor.

Description

Technical Field

[0001] This disclosure relates to the field of air conditioning technology, and in particular to a heat pump unit, an air conditioner, and a control method. Background Technology

[0002] In recent years, the combination of evaporative condensing technology and air-source heat pump technology has become a new direction in heat pump product research, resulting in a series of new evaporative heat pump units. In some heat pump units, the evaporative condenser and the air-cooled condenser are connected in parallel. When cooling is required, both the evaporative condenser and the air-cooled condenser participate in heat exchange to improve the cooling effect. When heating is required, because the spray water from the evaporative condenser is prone to freezing, the air-cooled condenser participates in heat exchange, but the evaporative condenser does not participate in heat exchange. This leads to a reduction in the amount of refrigerant actually circulating in the heat pump unit, resulting in a decrease in heating efficiency. To improve the heating efficiency of the heat pump unit, it is usually necessary to transfer the refrigerant from the evaporative condenser to the heating circulation path of the heat pump unit. In related technologies, the refrigerant from the evaporative condenser is generally introduced into the compressor through pressure difference or a refrigerant pump; however, these methods are costly and may have a negative impact on the compressor. Summary of the Invention

[0003] In view of this, in order to solve the technical problem that the refrigerant retention in the evaporator-condenser of the heat pump unit in the heating mode leads to a decrease in heating efficiency in the prior art, this disclosure provides a heat pump unit, an air conditioner and a control method.

[0004] According to a first aspect of the present disclosure, a heat pump unit is provided, the heat pump unit including a refrigerant main circuit, a first heat exchange flow path and a second heat exchange flow path, the first heat exchange flow path including a first sub-flow path, an air-cooled condenser and a second sub-flow path connected in sequence, the second heat exchange flow path including a third sub-flow path, an evaporative condenser and a fourth sub-flow path connected in sequence, the first sub-flow path and the third sub-flow path are both connected to a first end of the refrigerant main circuit, and the second sub-flow path and the fourth sub-flow path are both connected to a second end of the refrigerant main circuit;

[0005] The third sub-flow path includes a first control valve. The heat pump unit further includes an ejector, a first ejector branch, a second ejector branch, and a third ejector branch. The first ejector branch includes a second control valve, and the second ejector branch includes a third control valve. The outlet of the first ejector branch is connected to the first refrigerant port of the ejector. The inlet of the first ejector branch is connected to the refrigerant main circuit, and the connection position is located upstream of the electronic expansion valve in the refrigerant main circuit during heating. The upstream of the electronic expansion valve during heating refers to the upstream side of the electronic expansion valve in the refrigerant main circuit when the heat pump unit is in heating mode. The inlet of the second ejector branch is connected to the second refrigerant port of the ejector. The outlet of the second ejector branch is connected to the third sub-flow path, and the connection position is located on the side of the first control valve away from the evaporative condenser. The outlet of the third ejector branch is connected to the third refrigerant port of the ejector, and the inlet of the third ejector branch is connected to the first refrigerant port and / or the second refrigerant port of the evaporative condenser.

[0006] When the heat pump unit is in heating mode, if the heat pump unit meets the ejector start-up conditions, the first control valve is controlled to be closed, and the second control valve and the third control valve are both controlled to be open, so as to eject the refrigerant in the evaporator-condenser into the heating circulation path of the heat pump unit.

[0007] In one alternative implementation,

[0008] The inlet of the third ejector branch is connected to the first refrigerant port of the evaporative condenser through the third sub-flow path, and the connection position is located on the side of the first control valve in the third sub-flow path near the first refrigerant port of the evaporative condenser.

[0009] In one alternative implementation,

[0010] The third sub-flow path includes a one-way valve, which allows the refrigerant in the third sub-flow path to flow from the first refrigerant port of the evaporative condenser toward the connection point between the third sub-flow path and the refrigerant main path. The outlet of the second ejector branch is located between the one-way valve and the control valve at the connection point between the second ejector branch and the third sub-flow path.

[0011] In one alternative implementation,

[0012] The refrigerant main circuit includes an evaporator, which is located upstream of the electronic expansion valve in the heating phase, and the inlet of the first ejector branch is connected to the evaporator.

[0013] In one alternative implementation,

[0014] The third ejector branch includes a fourth control valve.

[0015] In one alternative implementation,

[0016] The fourth sub-flow path includes a fifth control valve, and the inlet of the third ejector branch is connected to the second refrigerant port of the evaporative condenser through the fourth sub-flow path;

[0017] Specifically, the inlet of the third ejector branch and the connection point of the fourth sub-flow path are located on the side of the fifth control valve away from the evaporator-condenser, or the inlet of the third ejector branch and the connection point of the fourth sub-flow path are located on the side of the fifth control valve closer to the evaporator-condenser.

[0018] According to a second aspect of the present disclosure, an air conditioner is provided, the air conditioner comprising a heat pump unit as described in any of the first aspects.

[0019] According to a third aspect of the present disclosure, a control method is provided, the control method being applied to a heat pump unit as described in any of the first aspects, the control method comprising:

[0020] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the first control valve of the heat pump unit is controlled to be closed, and the second and third control valves of the heat pump unit are both controlled to be open, so as to eject the refrigerant in the evaporator-condenser of the heat pump unit into the heating circulation path of the heat pump unit.

[0021] In one alternative implementation,

[0022] The refrigerant circuit of the heat pump unit includes a compressor, and determining that the heat pump unit meets the ejector start-up conditions includes:

[0023] The discharge pressure Pc of the compressor is determined to satisfy Pc < 650 kPa × [1 + (Q - 25%)]; where Pc is the discharge pressure of the compressor and Q is the load of the compressor.

[0024] In one alternative implementation,

[0025] The step of determining that the heat pump unit meets the ejector start-up conditions also includes:

[0026] It is determined that the ambient temperature of the heat pump unit is greater than the set temperature threshold.

[0027] In one alternative implementation,

[0028] The control method includes:

[0029] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejection exit condition, the first control valve, the second control valve, and the third control valve are all controlled to be closed to prevent the refrigerant in the evaporator-condenser of the heat pump unit from being ejected into the heating circulation path of the heat pump unit.

[0030] In one alternative implementation,

[0031] The determination that the heat pump unit meets the ejector exit conditions includes:

[0032] The internal pressure of the air-cooled condenser of the heat pump unit and the load of the compressor of the heat pump unit are determined to satisfy Pa < P1 × (Q - 25%) / 65%, and the internal pressure of the evaporative condenser is determined to satisfy Pb < P2; where Pa is the internal pressure of the air-cooled condenser, Pb is the internal pressure of the evaporative condenser, P1 is the first set pressure, P2 is the second set pressure, and Q is the load of the compressor.

[0033] In one alternative implementation,

[0034] The control method includes:

[0035] When the heat pump unit is in cooling mode, the first control valve is controlled to be in the open state, and the second control valve and the third control valve are controlled to be in the closed state.

[0036] In one alternative implementation,

[0037] When the third ejector branch includes a fourth control valve, the control method includes:

[0038] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the fourth control valve is controlled to be in the open state.

[0039] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector exit conditions, the fourth control valve is controlled to be in the closed state.

[0040] When the heat pump unit is in cooling mode, the fourth control valve is kept closed.

[0041] In one alternative implementation,

[0042] When the fourth sub-flow path includes a fifth control valve, and the inlet of the third ejector branch is connected to the fourth sub-flow path at a position opposite to the evaporative condenser of the fifth control valve, the control method includes:

[0043] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the fifth control valve is controlled to be in the open state.

[0044] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector exit conditions, the fifth control valve is controlled to be in the closed state.

[0045] In one alternative implementation,

[0046] When the fourth sub-flow path includes a fifth control valve, and the inlet of the third ejector branch is connected to the fourth sub-flow path at a position near the evaporative condenser of the fifth control valve, the control method includes:

[0047] When the heat pump unit is in heating mode, the fifth control valve is kept closed.

[0048] In one alternative implementation,

[0049] When the fourth sub-flow path includes a fifth control valve, the control method includes:

[0050] When the heat pump unit is in cooling mode, after the fifth control valve is opened at an initial opening degree, the opening degree of the fifth control valve is gradually increased until the fifth control valve reaches its maximum opening degree.

[0051] In one alternative implementation,

[0052] The step of gradually increasing the opening of the fifth control valve until the fifth control valve reaches its maximum opening includes:

[0053] If the internal pressure of the air-cooled condenser of the heat pump unit and the internal pressure of the evaporative condenser satisfy Pb≥Pa-100kPa, then the opening degree of the fifth control valve is increased at the first opening speed; where Pa is the internal pressure of the air-cooled condenser and Pb is the internal pressure of the evaporative condenser.

[0054] In one alternative implementation,

[0055] The step of gradually increasing the opening of the fifth control valve until the fifth control valve reaches its maximum opening includes:

[0056] If the internal pressure of the air-cooled condenser of the heat pump unit and the internal pressure of the evaporative condenser satisfy Pb < Pa - 100 kPa, then the opening degree of the fifth control valve is increased at a second opening speed; wherein the second opening speed is less than the first opening speed.

[0057] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: In this disclosure, the first heat exchange flow path and the second heat exchange flow path of the heat pump unit are arranged in parallel. When the heat pump unit is in the heating mode, the first control valve is in the closed state, and the air-cooled condenser in the first heat exchange flow path participates in heat exchange, while the evaporative cold condenser in the second heat exchange flow path does not participate in heat exchange. In this case, considering the reduced heating efficiency due to the decreased amount of refrigerant participating in heat exchange in the heat pump unit, an ejector, a first ejector branch, a second ejector branch, and a third ejector branch are added to the heat pump unit. When the heat pump unit meets the ejector start-up conditions, both the second and third control valves can be controlled to be open, thus ensuring that both the first and second ejector branches are conductive. Since the inlet of the first ejector branch is connected to the upstream heating side of the electronic expansion valve of the refrigerant main circuit, and the outlet of the second ejector branch is connected to the third sub-path, both the third and first sub-paths are connected to the first end of the refrigerant main circuit, that is, to the downstream heating side of the electronic expansion valve of the refrigerant main circuit. The refrigerant pressure on the upstream side of the heating system is greater than that on the downstream side. Therefore, a portion of the refrigerant in the main refrigerant circuit can be transferred along the first ejector branch, the ejector, the second ejector branch, and the third sub-circuit, and then return to the heating circulation path of the heat pump unit. When the aforementioned portion of the refrigerant passes through the ejector, since the third ejector branch connected to the ejector is connected to the first and / or second refrigerant ports of the evaporator-condenser, the refrigerant in the evaporator-condenser can be ejected to the second ejector branch through the third ejector branch and the ejector, and then enter the heating circulation path of the heat pump unit through the third sub-circuit. This allows the refrigerant retained in the evaporator-condenser to participate in the heating process of the heat pump unit, thereby improving the heating efficiency of the heat pump unit. Furthermore, the scheme disclosed herein, which redirects the refrigerant retained in the evaporator-condenser into the heating cycle of the heat pump unit, eliminates the need for an additional refrigerant pump. Instead of directly transferring refrigerant to the compressor, a refrigerant is redirected via an ejector to the downstream side of the electronic expansion valve for heating. This not only reduces costs but also avoids negative impacts on the compressor. In other words, this disclosure allows for the reintroduction of refrigerant retained in the evaporator-condenser into the heating cycle of the heat pump unit while maintaining low costs and without negatively affecting the compressor. This improves the heating efficiency of the heat pump unit and enhances the user experience.

[0058] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0059] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0062] Figure 1 This is a schematic diagram of the flow path of a heat pump unit according to an exemplary embodiment.

[0063] Figure 2 This is another flow path diagram of a heat pump unit according to an exemplary embodiment.

[0064] Figure 3 This is a flowchart illustrating a control method according to an exemplary embodiment.

[0065] in:

[0066] 1. Air-cooled condenser; 2. Evaporative condenser; 3. Electronic expansion valve; 4. Evaporator; 5. Compressor; 6. Four-way valve; 7. Ejector;

[0067] 11. First control valve; 12. Second control valve; 13. Third control valve; 14. Fourth control valve; 15. Fifth control valve; 16. Sixth control valve; 17. Seventh control valve; 18. Check valve. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0069] The following disclosure provides numerous different embodiments or examples for implementing various aspects of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0070] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0071] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0072] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0073] To address the technical problem of reduced heating efficiency caused by refrigerant retention in the evaporator-condenser of a heat pump unit during heating mode, this disclosure provides a heat pump unit, an air conditioner, and a control method.

[0074] In this disclosure, the first heat exchange flow path and the second heat exchange flow path of the heat pump unit are connected in parallel. When the heat pump unit is in heating mode, the first control valve is closed, and the air-cooled condenser in the first heat exchange flow path participates in heat exchange, while the evaporative condenser in the second heat exchange flow path does not participate in heat exchange. In this case, considering the reduced heating efficiency due to the decreased amount of refrigerant participating in heat exchange in the heat pump unit, an ejector, a first ejector branch, a second ejector branch, and a third ejector branch are added to the heat pump unit. When the heat pump unit meets the ejector start-up conditions, both the second and third control valves can be controlled to be open, thus ensuring that both the first and second ejector branches are conductive. Since the inlet of the first ejector branch is connected to the upstream heating side of the electronic expansion valve of the refrigerant main circuit, and the outlet of the second ejector branch is connected to the third sub-path, both the third and first sub-paths are connected to the first end of the refrigerant main circuit, that is, to the downstream heating side of the electronic expansion valve of the refrigerant main circuit. The refrigerant pressure on the upstream side of the heating system is greater than that on the downstream side. Therefore, a portion of the refrigerant in the main refrigerant circuit can be transferred along the first ejector branch, the ejector, the second ejector branch, and the third sub-circuit, and then return to the heating circulation path of the heat pump unit. When the aforementioned portion of the refrigerant passes through the ejector, since the third ejector branch connected to the ejector is connected to the first and / or second refrigerant ports of the evaporator-condenser, the refrigerant in the evaporator-condenser can be ejected to the second ejector branch through the third ejector branch and the ejector, and then enter the heating circulation path of the heat pump unit through the third sub-circuit. This allows the refrigerant retained in the evaporator-condenser to participate in the heating process of the heat pump unit, thereby improving the heating efficiency of the heat pump unit. Furthermore, the scheme disclosed herein, which redirects the refrigerant retained in the evaporator-condenser into the heating cycle of the heat pump unit, eliminates the need for an additional refrigerant pump. Instead of directly transferring refrigerant to the compressor, a refrigerant is redirected via an ejector to the downstream side of the electronic expansion valve for heating. This not only reduces costs but also avoids negative impacts on the compressor. In other words, this disclosure allows for the reintroduction of refrigerant retained in the evaporator-condenser into the heating cycle of the heat pump unit while maintaining low costs and without negatively affecting the compressor. This improves the heating efficiency of the heat pump unit and enhances the user experience.

[0075] In one exemplary embodiment, reference Figures 1 to 3As shown, a heat pump unit is provided, as well as an air conditioner including the aforementioned heat pump unit, and a control method applied to the heat pump unit, i.e., the heat pump unit is used to implement the aforementioned control method. In this embodiment, the heat pump unit may include a refrigerant main circuit, a first heat exchange flow path, and a second heat exchange flow path. The first heat exchange flow path includes a first sub-flow path, an air-cooled condenser 1, and a second sub-flow path connected in sequence. The second heat exchange flow path includes a third sub-flow path, an evaporative condenser 2, and a fourth sub-flow path connected in sequence. The first sub-flow path and the third sub-flow path are both connected to a first end of the refrigerant main circuit, and the second sub-flow path and the fourth sub-flow path are both connected to a second end of the refrigerant main circuit, thereby realizing the parallel connection of the first heat exchange flow path and the second heat exchange flow path, that is, realizing the parallel connection of the air-cooled condenser 1 and the evaporative condenser 2.

[0076] In this embodiment, when the heat pump unit is in cooling mode, both the first and second heat exchange paths participate in heat exchange. That is, both the air-cooled condenser 1 and the evaporative condenser 2 participate in heat exchange, thereby improving the cooling efficiency of the heat pump unit and enhancing the user experience. When the heat pump unit is in heating mode, because the spray water from the evaporative condenser 2 may freeze, only the first heat exchange path participates in heat exchange, while the second heat exchange path does not. That is, the air-cooled condenser 1 participates in heat exchange in heating mode, but the evaporative condenser 2 no longer participates. For example, a first control valve 11 can be installed in the third sub-path. By closing the first control valve 11, the flow of refrigerant in the first heat exchange path is cut off, thus preventing the first heat exchange path from participating in heat exchange. This results in the refrigerant in the evaporative condenser 2 not participating in the heating process, leading to insufficient refrigerant in the heating circulation path of the heat pump unit, and consequently, a decrease in the heating efficiency of the heat pump unit.

[0077] In this embodiment, the heat pump unit further includes an ejector 7, a first ejector branch, a second ejector branch, and a third ejector branch. The first ejector branch includes a second control valve 12 for controlling the opening or closing of the first ejector branch. The second ejector branch includes a third control valve 13 for controlling the opening or closing of the second ejector branch. The outlet of the first ejector branch is connected to the first refrigerant port of the ejector 7, and the inlet of the first ejector branch is connected to the refrigerant main circuit, with the connection located upstream of the electronic expansion valve 3 in the refrigerant main circuit during heating. The upstream of the electronic expansion valve 3 during heating refers to the flow path between the outlet of the compressor 5 and the electronic expansion valve 3 in the refrigerant main circuit when the heat pump unit is in heating mode. For example, the heat pump unit may include an evaporator 4, located upstream of the electronic expansion valve 3 during heating, with the inlet of the first ejector branch connected to the evaporator 4. By diverting a portion of the refrigerant from the evaporator 4 to the first ejector branch, the refrigerant diversion from the first ejector branch can avoid excessive impact on the refrigerant stability of the main refrigerant circuit, thus better ensuring heating stability.

[0078] In this embodiment, the inlet of the second ejector branch is connected to the second refrigerant port of the ejector 7, and the outlet of the second ejector branch is connected to the third sub-flow path, with the connection point located on the side of the first control valve 11 away from the evaporative condenser 2. That is, the connection point between the outlet of the second ejector branch and the third sub-flow path is located between the first control valve 11 and the first end. In other words, in this embodiment, the first ejector branch, the ejector 7, and the second ejector branch form the main ejection path.

[0079] The outlet of the third ejector branch is connected to the third refrigerant port of the ejector 7, and the inlet of the third ejector branch is connected to the first and / or second refrigerant port of the evaporative condenser 2. This facilitates the ejection of refrigerant from the evaporative condenser 2 to the third ejector branch via the ejector 7, which then transfers the refrigerant to the second ejector branch, then into the third sub-flow path, and finally into the heating circulation path of the heat pump unit. It should be noted that the heating circulation path refers to the refrigerant circulation path formed by the main refrigerant path and the first heat exchange path. In this embodiment, the third ejector branch forms an auxiliary ejector path. At the ejector 7, the refrigerant from the main ejector path is transferred via pressure difference, thereby ejecting the refrigerant from the auxiliary ejector path into the ejector 7.

[0080] In the heating mode of the heat pump unit, the first control valve 11 is closed, and the second heat exchange path no longer participates in heat exchange. At this time, if the heat pump unit meets the ejector start-up conditions, the ejector can be activated by controlling the second control valve 12 and the third control valve 13 to be open, thereby making both the first ejector branch and the second ejector branch conductive. Since the inlet of the first ejector branch is connected to the upstream side of the electronic expansion valve 3 of the refrigerant main circuit for heating, and the outlet of the second ejector branch is connected to the third sub-path, and both the third sub-path and the first sub-path are connected to the first end of the refrigerant main circuit, that is, to the downstream side of the electronic expansion valve 3 of the refrigerant main circuit for heating, and the refrigerant pressure on the upstream side of the electronic expansion valve 3 for heating is greater than the refrigerant pressure on the downstream side for heating, part of the refrigerant in the refrigerant main circuit can be transferred along the first ejector branch, ejector 7, second ejector branch, and third sub-path, and then return to the heating circulation path of the heat pump unit.

[0081] In other words, when the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the ejector can be activated. This means controlling the first control valve 11 of the heat pump unit to be closed, and controlling the second control valve 12 and the third control valve 13 to be open, so as to eject the refrigerant in the evaporator-condenser 2 of the heat pump unit into the heating circulation path of the heat pump unit. It should be noted that after determining that the heat pump unit meets the ejector start-up conditions, it is necessary to control the first control valve 11 to be closed and the second control valve 12 and the third control valve 13 to be open, but it is not necessary to switch the states of the above control valves. For example, when it is determined that the heat pump unit meets the ejector start-up conditions, if the first control valve 11 is already closed, it can be controlled to continue to remain closed. For example, when it is determined that the heat pump unit meets the ejector start-up conditions, if the second control valve 12 is in the closed state, it is necessary to switch the second control valve 12 to the open state so that the second control valve 12 is in the open state.

[0082] In this embodiment, after controlling the first control valve 11 of the heat pump unit to be closed and controlling the second control valve 12 and the third control valve 13 of the heat pump unit to be open, when part of the refrigerant in the above-mentioned refrigerant main circuit passes through the flow path formed by the first ejector branch, the ejector 7 and the second ejector branch, since the third ejector branch connected to the ejector 7 is connected to the first refrigerant port and / or the second refrigerant port of the evaporative condenser 2, the refrigerant in the evaporative condenser 2 can be ejected to the second ejector branch through the third ejector branch and the ejector 7, and then enter the heating circulation flow path of the heat pump unit through the third sub-flow path, so that the refrigerant retained in the evaporative condenser 2 participates in the heating process of the heat pump unit, thereby improving the heating efficiency of the heat pump unit.

[0083] It should be noted that in the heat pump unit of this embodiment, when the third ejector branch is connected to the first refrigerant port of the evaporative condenser 2, the inlet of the third ejector branch can be connected to the first refrigerant port of the evaporative condenser 2 through the third sub-flow path, and the connection position is located on the side of the first control valve 11 in the third sub-flow path close to the first refrigerant port of the evaporative condenser 2. In this case, when the heat pump unit is in heating mode and the first control valve 11 is controlled to be closed, when it is necessary to open the ejector, it can still be ensured that the refrigerant of the evaporative condenser 2 is ejected to the ejector 7 through the first refrigerant port, and then enters the heating circulation path after passing through the second ejector branch and the third sub-flow path.

[0084] In this embodiment of the heat pump unit, the third sub-flow path may include a one-way valve 18. The one-way valve 18 allows the refrigerant in the third sub-flow path to flow from the first refrigerant port of the evaporative condenser 2 towards the connection point between the third sub-flow path and the main refrigerant path, and prohibits the refrigerant from flowing backwards at the location of the one-way valve 18. This prevents refrigerant from the main refrigerant path and the first sub-flow path from flowing back into the third sub-flow path. The connection point between the outlet of the second ejector branch and the third sub-flow path is located between the one-way valve 18 and the control valve. Therefore, when the refrigerant in the evaporative condenser 2 is ejected into the heating circulation path, backflow of refrigerant from the heating circulation path into the third sub-flow path can be prevented, thus better ensuring that the refrigerant in the evaporative condenser 2 is introduced into the heating circulation path.

[0085] The refrigerant circuit of the heat pump unit may include compressor 5. Determining that the heat pump unit meets the ejector start-up conditions may include determining that the discharge pressure Pc of the compressor 5 and the load satisfy Pc < 650 kPa × [1 + (Q - 25%)]; where Pc is the discharge pressure of the compressor 5 and Q is the load of the compressor 5. It should be noted that when the heat pump unit is in heating mode, if the discharge pressure Pc of the compressor 5 is determined to be < 650 kPa × [1 + (Q - 25%)], it indicates that the amount of refrigerant in the heating circulation path of the heat pump unit is insufficient, that is, the amount of refrigerant participating in the circulation of the heat pump unit is small, indicating that refrigerant needs to be added to the heating circulation path. Therefore, the heat pump unit is considered to meet the ejector start-up conditions, and the heat pump unit can be controlled to start ejection, that is, the first control valve 11 is controlled to remain closed, and the second control valve 12 and the third control valve 13 are controlled to be open. In this way, the refrigerant of the evaporator condenser 2 is ejected into the heating circulation path by utilizing the refrigerant pressure difference between the upstream and downstream sides of the electronic expansion valve 3, thereby increasing the amount of refrigerant participating in the circulation of the heat pump unit, so as to increase the discharge pressure of the compressor 5 and improve the heating efficiency.

[0086] It should also be noted that the refrigerant requirement of a heat pump unit is related not only to its cooling efficiency but also to the ambient temperature. In this embodiment, determining that the heat pump unit meets the ejector start-up conditions when it is in heating mode may further include: determining that the ambient temperature of the heat pump unit is greater than a set temperature threshold. That is, if it is determined that the discharge pressure Pc of the compressor 5 is less than 650 kPa × [1 + (Q - 25%)] and the ambient temperature is greater than the set temperature threshold, it indicates that the heating circulation path requires more refrigerant to participate in heat exchange. Therefore, it can be considered that the heat pump unit meets the ejector start-up conditions, and the heat pump unit can be controlled to start ejection. This utilizes the refrigerant pressure difference between the upstream and downstream sides of the electronic expansion valve 3 to eject the refrigerant from the evaporator condenser 2 into the heating circulation path, thereby increasing the amount of refrigerant participating in the circulation in the heat pump unit, increasing the discharge pressure of the compressor 5, and improving the heating efficiency.

[0087] It should be noted that the temperature threshold can be set according to the actual situation, and its specific value is not limited. For example, the temperature threshold can be set to 10℃.

[0088] Furthermore, when the heat pump unit is in heating mode, during the process of the ejector 7 introducing the refrigerant from the evaporator-condenser 2 into the heating circulation path, it can be determined in real time or periodically whether the heat pump unit meets the ejector exit condition. If it is determined that the heat pump unit meets the ejector exit condition, the ejector can be shut off, that is, the first control valve 11, the second control valve 12, and the third control valve 13 are all controlled to be in the closed state, so as to prevent the refrigerant in the evaporator-condenser 2 of the heat pump unit from being ejected into the heating circulation path of the heat pump unit.

[0089] With both the second control valve 12 and the third control valve 13 closed, no refrigerant flows through the flow path formed by the first ejector branch, ejector 7, and the second ejector branch. Therefore, ejector 7 no longer ejects the refrigerant from the evaporator-condenser 2 of the heat pump unit into the heating cycle flow path of the heat pump unit. In this case, the refrigerant in the main refrigerant line no longer diverts a portion to participate in the ejection of refrigerant from the evaporator-condenser 2, and can fully participate in the heating cycle to better ensure heating efficiency.

[0090] Determining that the heat pump unit meets the ejector termination conditions may include: determining that the internal pressure of the air-cooled condenser 1 of the heat pump unit and the load of the compressor 5 satisfy Pa < P1 × (Q - 25%) / 65%, and determining that the internal pressure of the evaporative condenser 2 satisfies Pb < P2; where Pa is the internal pressure of the air-cooled condenser 1, Pb is the internal pressure of the evaporative condenser 2, P1 is the first set pressure, P2 is the second set pressure, and Q is the load of the compressor 5. The first and second set pressures can be set according to actual needs, and their specific values ​​are not limited. For example, the first set pressure can be greater than or equal to 800 kPa and less than or equal to 1200 kPa, specifically 1000 kPa. The second set pressure can be greater than or equal to 100 kPa and less than or equal to 500 kPa, specifically 300 kPa.

[0091] It should be noted that when Pa < P1 × (Q - 25%) / 65% and Pb < P2, it indicates that most of the refrigerant in the evaporative condenser 2 has already been diverted into the heating circulation path, and no further diversion is required. Therefore, under these conditions, the first control valve 11, the second control valve 12, and the third control valve 13 can all be kept in the closed state.

[0092] In addition, in this embodiment, when the heat pump unit is in cooling mode, the first control valve 11 can be controlled to be in the open state, and the second control valve 12 and the third control valve 13 can be controlled to be in the closed state. In this case, the first ejector branch, the second ejector branch, the ejector 7 and the third ejector branch no longer participate in the transmission of refrigerant. The heat pump unit uses the parallel evaporator condenser 2 and the air-cooled condenser 1 to cool together to ensure the cooling effect.

[0093] In this embodiment, the heat pump unit can not only utilize the parallel evaporator-condenser 2 and the air-cooled condenser 1 for cooling, but also guide the evaporator-condenser 2 to the heating circulation path via an ejector in heating mode. That is, this embodiment introduces the refrigerant retained in the evaporator-condenser 2 into the heating circulation path of the heat pump unit without requiring an additional refrigerant pump. Instead of directly transferring the refrigerant to the compressor 5, the refrigerant from the evaporator-condenser 2 is ejected to the downstream side of the electronic expansion valve 3 via the ejector 7. This not only reduces costs but also avoids negative impacts on the compressor 5. In other words, this embodiment can reintroduce the refrigerant retained in the evaporator-condenser 2 into the heating circulation path of the heat pump unit while maintaining low costs and without negatively impacting the compressor 5, thereby improving the heating efficiency of the heat pump unit and enhancing the user experience.

[0094] In one exemplary embodiment, reference Figures 1 to 3As shown, a heat pump unit is provided, as well as an air conditioner including the aforementioned heat pump unit, and a control method applied to the heat pump unit, i.e., the heat pump unit is used to implement the aforementioned control method. In the heat pump unit of this embodiment, the third ejector branch includes a fourth control valve 14 for controlling the opening or closing of the third ejector branch.

[0095] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, it means that the refrigerant of the evaporator condenser 2 needs to be ejected into the heating circulation path. The heat pump unit can then be controlled to start ejection, that is, the fourth control valve 14 can be controlled to be in the open state so that the third ejector branch is connected. This allows the refrigerant of the evaporator condenser 2 to be ejected into the heating circulation path, thereby increasing the amount of refrigerant participating in the heating cycle and thus improving the heating efficiency of the heat pump unit.

[0096] When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector exit condition, it means that there is no need to set the heating circulation path for the refrigerant in the evaporator condenser 2. The heat pump unit can be controlled to shut off the ejector, that is, the fourth control valve 14 can be controlled to be in the closed state to avoid the refrigerant in the evaporator condenser 2 being introduced into the heating circulation path and causing fluctuations in the heating effect.

[0097] When the heat pump unit is in cooling mode, both the evaporative condenser 2 and the air-cooled condenser 1, which need to be connected in parallel, participate in heat exchange. That is, at this time, the evaporative condenser 2 is in the refrigeration cycle flow path and there is no need to eject the refrigerant inside. Therefore, the fourth control valve 14 can be controlled to be in the closed state to ensure the stability of the entire refrigeration cycle.

[0098] In this embodiment, a fourth control valve 14 is installed in the heat pump unit, which can precisely control the on / off state of the third ejector branch to adapt to different operating modes and working conditions, thereby improving the user experience.

[0099] Additionally, in this embodiment of the heat pump unit, the fourth sub-flow path may include a fifth control valve 15. The inlet of the third ejector branch can be connected to the second refrigerant port of the evaporative condenser 2 through the fourth sub-flow path.

[0100] Among them, reference Figure 1 As shown, the connection point between the inlet of the third ejector branch and the fourth sub-flow path can be located on the side of the fifth control valve 15 away from the evaporator condenser 2.

[0101] It should be noted that when the connection between the inlet of the third ejector branch and the fourth sub-flow path can be located on the side of the fifth control valve 15 away from the evaporator-condenser 2, it indicates that the fifth control valve 15 is located between the aforementioned connection position and the second refrigerant port of the evaporator-condenser 2. In this case, when the heat pump unit is in heating mode, since the evaporator-condenser 2 does not participate in heat exchange in the heating mode, both the fifth control valve 15 and the first control valve 11 can be controlled to be in the closed state to better prevent the refrigerant in the refrigerant main line from entering the evaporator-condenser 2 through the fourth sub-flow path. In this case, if it is determined that the heat pump unit meets the ejector start-up conditions, the heat pump unit can be controlled to start ejection, that is, the first control valve 11 can be controlled to remain in the closed state, and the second control valve 12, the third control valve 13, the fourth control valve 14, and the fifth control valve 15 can all be controlled to be in the open state, so that the refrigerant in the evaporator-condenser 2 can enter the third ejector branch through the fifth control valve 15, and then be ejected to the heating circulation path through the ejector 7.

[0102] Additionally, in this embodiment, reference Figure 2 As shown, the connection point between the inlet of the third ejector branch and the fourth sub-flow path can also be located on the side of the fifth control valve 15 near the evaporator condenser 2.

[0103] It should be noted that when the connection between the inlet of the third ejector branch and the fourth sub-flow path is located on the side of the fifth control valve 15 near the evaporator-condenser 2, it means that the connection between the inlet of the third ejector branch and the fourth sub-flow path is located between the fifth control valve 15 and the second refrigerant port of the evaporator-condenser 2. In this case, when the heat pump unit is in heating mode, since the evaporator-condenser 2 does not participate in the heat exchange in the heating mode, both the fifth control valve 15 and the first control valve 11 can be controlled to be in the closed state, so as to better prevent the refrigerant in the refrigerant main line from entering the evaporator-condenser 2 through the fourth sub-flow path. In this case, if it is determined that the heat pump unit meets the ejector start-up conditions, the heat pump unit can be controlled to start ejection, that is, the first control valve 11 and the fifth control valve 15 are kept closed, and the second control valve 12, the third control valve 13 and the fourth control valve 14 are all kept open. During the process of the refrigerant of the evaporator condenser 2 being ejected to the heating circulation path through the ejector 7, the closure of the fifth control valve 15 can prevent the refrigerant in the refrigerant main circuit from entering the third ejector branch through the fourth sub-circuit, so that the refrigerant of the evaporator condenser 2 can be guided to the heating circulation path more accurately.

[0104] When the heat pump unit includes a fifth control valve 15, regardless of whether the connection between the inlet of the third ejector branch and the fourth sub-flow path is located between the fifth control valve 15 and the second refrigerant port of the evaporative condenser 2, the fifth control valve 15 can be controlled to open at an initial degree and then gradually increase the opening degree of the fifth control valve 15 until the fifth control valve 15 reaches its maximum opening degree (e.g., fully open) when the heat pump unit is in cooling mode.

[0105] It should be noted that when switching from heating mode to cooling mode, the refrigerant in the original heating circulation path will begin to enter the evaporator-condenser 2. If the opening of the fifth control valve 15 is directly opened to the maximum opening, it may impact the entire refrigerant circulation path of the heat pump unit. Therefore, the fifth control valve 15 can be opened at the initial opening (less than the maximum opening) first, and then the opening of the fifth control valve 15 can be gradually increased to reduce the impact.

[0106] The initial opening degree can be set according to actual needs, and its specific value is not limited. For example, the initial opening degree can be 30%. That is, the initial opening degree is 30% of the maximum opening degree of the fifth control valve 15.

[0107] During the gradual increase of the opening degree of the fifth control valve 15, the rate of increase can be determined based on the internal pressures of the air-cooled condenser 1 and the evaporative condenser 2 of the heat pump unit. If the internal pressures of the air-cooled condenser 1 and the evaporative condenser 2 satisfy Pb ≥ Pa - 100 kPa, the opening degree of the fifth control valve 15 is increased at a first opening rate. If the internal pressures of the air-cooled condenser 1 and the evaporative condenser 2 satisfy Pb < Pa - 100 kPa, the opening degree of the fifth control valve 15 is increased at a second opening rate. Here, Pa is the internal pressure of the air-cooled condenser 1, Pb is the internal pressure of the evaporative condenser 2, and the second opening rate is less than the first opening rate.

[0108] It should be noted that when the heat pump unit is in cooling mode, the first heat exchange flow path and the refrigerant main flow path constitute the first refrigeration cycle flow path, and the second heat exchange flow path and the refrigerant main flow path constitute the second refrigeration cycle flow path. When Pb < Pa - 100 kPa, it indicates that the refrigerant pressure difference between the first and second refrigeration cycle flow paths is still relatively large. In this case, the fifth control valve 15 can be controlled to increase its opening at a smaller first opening speed to avoid impacting the heat pump unit. When Pb ≥ Pa - 100 kPa, it indicates that the refrigerant pressure between the first and second refrigeration cycle flow paths is close to equilibrium. In this case, the fifth control valve 15 can be controlled to increase its opening at a larger second opening speed.

[0109] In this embodiment, by setting the fifth control valve 15, the refrigerant flow direction can be controlled more precisely, the mode switching process can be smoothed, and the heat exchange load distribution can be optimized. While ensuring the safe and reliable operation of the heat pump unit, the efficiency and stability of the heat pump unit during heating, cooling and mode switching can be significantly improved.

[0110] In one exemplary embodiment, reference Figure 1 and Figure 3 As shown, a heat pump unit is provided, as well as an air conditioner including the aforementioned heat pump unit, and a control method applied to the heat pump unit, i.e., the heat pump unit is used to implement the aforementioned control method. The heat pump unit of this embodiment includes a refrigerant main circuit, a first heat exchange flow path, and a second heat exchange flow path. The first heat exchange flow path includes a first sub-flow path, an air-cooled condenser 1, and a second sub-flow path connected in sequence. The second heat exchange flow path includes a third sub-flow path, an evaporative condenser 2, and a fourth sub-flow path connected in sequence. The first and third sub-flow paths are both connected to a first end of the refrigerant main circuit, and the second and fourth sub-flow paths are both connected to a second end of the refrigerant main circuit, thereby achieving parallel connection of the first and second heat exchange flow paths, i.e., parallel connection of the air-cooled condenser 1 and the evaporative condenser 2.

[0111] The refrigerant flow path can include a sixth control valve 16, a second sub-flow path can include a seventh control valve 17, and a third sub-flow path can include a first control valve 11. The third sub-flow path can also include a one-way valve 18, which allows the refrigerant in the third sub-flow path to flow from the first refrigerant port of the evaporator-condenser 2 towards the connection point between the third sub-flow path and the refrigerant main flow path, and prohibits the refrigerant from flowing in the reverse direction at the one-way valve 18 position. A fourth sub-flow path can include a fifth control valve 15. The refrigerant main flow path can include an electronic expansion valve 3, an evaporator 4, a compressor 5, and a four-way valve 6. The outlet of the compressor 5 is connected to the fourth port of the four-way valve 6, and the inlet of the compressor 5 is connected to the third port of the four-way valve 6. The second port of the four-way valve 6 is connected to the first port of the electronic expansion valve 3 through the evaporator 4. The electronic expansion valve 3 can also serve as the first end of the refrigerant main flow path, connecting to both the first and third sub-flow paths respectively; that is, the second port of the electronic expansion valve 3 can connect to both the first and third sub-flow paths respectively. The second end of the four-way valve 6, which forms the refrigerant main circuit, is connected to the second sub-flow path and the fourth sub-flow path respectively. For example, the fourth valve port of the four-way valve 6 can be connected to the fourth sub-flow path, and the first valve port of the four-way valve 6 can be connected to the second sub-flow path.

[0112] The heat pump unit also includes an ejector 7, a first ejector branch, a second ejector branch, and a third ejector branch. The first ejector branch includes a second control valve 12. The second ejector branch includes a third control valve 13. The outlet of the first ejector branch is connected to the first refrigerant port of the ejector 7, and the inlet of the first ejector branch is connected to the evaporator 4 of the refrigerant main circuit. The inlet of the second ejector branch is connected to the second refrigerant port of the ejector 7, and the outlet of the second ejector branch is connected to the third sub-flow path, with the connection point located on the side of the first control valve 11 away from the evaporator-condenser 2. The inlet of the third ejector branch can be connected to the second refrigerant port of the evaporator-condenser 2 through the fourth sub-flow path, and the connection point between the inlet of the third ejector branch and the fourth sub-flow path can be located on the side of the fifth control valve 15 away from the evaporator-condenser 2.

[0113] It should be noted that in this embodiment, the first control valve 11, the second control valve 12, the third control valve 13, the fourth control valve 14, the fifth control valve 15, the sixth control valve 16, and the seventh control valve 17 can all be solenoid valves, or other electric control valves, and there is no limitation on this.

[0114] In this embodiment, when the heat pump unit is in heating mode, the sixth control valve 16 and the seventh control valve 17 can be controlled to be in the open state, and the first control valve 11 can be controlled to be in the closed state. In addition, the fourth valve port of the four-way valve 6 can be controlled to be connected to the second valve port, and the first valve port can be connected to the third valve port, so that the air-cooled condenser 1 of the heat pump unit participates in heat exchange, while the evaporative condenser 2 does not participate in heat exchange.

[0115] In heating mode, if the discharge pressure Pc of compressor 5 is determined to be < 650 kPa × [1 + (Q - 25%)], and T is determined to be > 10℃, it indicates that the heating circulation path requires more refrigerant to participate in heat exchange. Therefore, the heat pump unit can be considered to meet the ejector start-up conditions, and the ejector can be activated by controlling the second control valve 12, the third control valve 13, the fourth control valve 14, and the fifth control valve 15 to be in the open state. This utilizes the refrigerant pressure difference between the upstream and downstream sides of the electronic expansion valve 3 to eject the refrigerant from the evaporator-condenser 2 into the heating circulation path, thereby increasing the amount of refrigerant participating in the circulation in the heat pump unit, increasing the discharge pressure of compressor 5, and improving heating efficiency. Wherein, Pc is the discharge pressure of compressor 5, Q is the load of compressor 5, and T is the ambient temperature.

[0116] In heating mode, if Pa < P1 × (Q - 25%) / 65% and Pb < P2, it indicates that most of the refrigerant in the evaporative condenser 2 has been ejected into the heating circulation path, and further ejection is unnecessary. This means the ejection exit condition is met, and the ejector can be closed. This means that the second control valve 12, third control valve 13, fourth control valve 14, and fifth control valve 15 are all closed, and the ejector 7 no longer ejects the refrigerant from the evaporative condenser 2 of the heat pump unit into the heating circulation path of the heat pump unit. Wherein, Pa is the internal pressure of the air-cooled condenser 1, and Pb is the internal pressure of the evaporative condenser 2. P1 is the first set pressure, which can be 1000 kPa. P2 is the second set pressure, which can be 300 kPa. Q is the load of the compressor 5.

[0117] After the heat pump unit switches from heating mode to cooling mode, the second control valve 12, the third control valve 13 and the fourth control valve 14 can be controlled to be closed, the first control valve 11, the sixth control valve 16 and the seventh control valve 17 can be controlled to be open, and the fifth control valve 15 can be controlled to open with an initial opening of 30%, and then the opening of the fifth control valve 15 can be gradually increased.

[0118] Specifically, during the process of increasing the opening of the fifth control valve 15, if the internal pressure of the air-cooled condenser 1 of the heat pump unit and the internal pressure of the evaporative condenser 2 satisfy Pb≥Pa-100kPa, then the opening of the fifth control valve 15 is increased at a first opening rate of 2% / minute; if the internal pressure of the air-cooled condenser 1 of the heat pump unit and the internal pressure of the evaporative condenser 2 satisfy Pb<Pa-100kPa, then the opening of the fifth control valve 15 is increased at a second opening rate of 4% / minute. Here, Pa is the internal pressure of the air-cooled condenser 1, and Pb is the internal pressure of the evaporative condenser 2.

[0119] The heat pump unit can not only utilize the parallel evaporator-condenser 2 and the air-cooled condenser 1 for cooling, but also guide the refrigerant from the evaporator-condenser 2 into the heating circulation path via an ejector in heating mode. That is, this embodiment introduces the refrigerant retained in the evaporator-condenser 2 into the heating circulation path of the heat pump unit. This eliminates the need for an additional refrigerant pump and avoids direct transmission to the compressor 5. Instead, the refrigerant from the evaporator-condenser 2 is ejected to the downstream side of the electronic expansion valve 3 via the ejector 7. This not only reduces costs but also avoids negative impacts on the compressor 5. In other words, this embodiment can reintroduce the refrigerant retained in the evaporator-condenser 2 into the heating circulation path of the heat pump unit while maintaining low costs and without negatively impacting the compressor 5, thereby improving the heating efficiency of the heat pump unit and enhancing the user experience.

[0120] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0121] It should be noted that the terms "one implementation," "embodiment," "exemplary embodiment," and "some embodiments" used in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0122] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or air conditioning apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or air conditioning apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or air conditioning apparatus that includes said element.

[0123] The above embodiments are merely preferred embodiments provided to fully illustrate this application, and the scope of protection of this application is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this application are all within the scope of protection of this application.

Claims

1. A heat pump unit, characterized in that, The heat pump unit includes a refrigerant main circuit, a first heat exchange flow path, and a second heat exchange flow path. The first heat exchange flow path includes a first sub-flow path, an air-cooled condenser, and a second sub-flow path connected in sequence. The second heat exchange flow path includes a third sub-flow path, an evaporative condenser, and a fourth sub-flow path connected in sequence. The first sub-flow path and the third sub-flow path are both connected to a first end of the refrigerant main circuit, and the second sub-flow path and the fourth sub-flow path are both connected to a second end of the refrigerant main circuit. The third sub-flow path includes a first control valve. The heat pump unit further includes an ejector, a first ejector branch, a second ejector branch, and a third ejector branch. The first ejector branch includes a second control valve, and the second ejector branch includes a third control valve. The outlet of the first ejector branch is connected to the first refrigerant port of the ejector. The inlet of the first ejector branch is connected to the refrigerant main circuit, and the connection position is located upstream of the electronic expansion valve in the refrigerant main circuit during heating. The upstream of the electronic expansion valve during heating refers to the upstream side of the electronic expansion valve in the refrigerant main circuit when the heat pump unit is in heating mode. The inlet of the second ejector branch is connected to the second refrigerant port of the ejector. The outlet of the second ejector branch is connected to the third sub-flow path, and the connection position is located on the side of the first control valve away from the evaporative condenser. The outlet of the third ejector branch is connected to the third refrigerant port of the ejector, and the inlet of the third ejector branch is connected to the first refrigerant port and / or the second refrigerant port of the evaporative condenser. When the heat pump unit is in heating mode, if the heat pump unit meets the ejector start-up conditions, the first control valve is controlled to be closed, and the second control valve and the third control valve are both controlled to be open, so as to eject the refrigerant in the evaporator-condenser into the heating circulation path of the heat pump unit.

2. The heat pump unit according to claim 1, characterized in that, The third sub-flow path includes a one-way valve, which allows the refrigerant in the third sub-flow path to flow from the first refrigerant port of the evaporative condenser toward the connection point between the third sub-flow path and the refrigerant main path. The outlet of the second ejector branch is located between the one-way valve and the control valve at the connection point between the second ejector branch and the third sub-flow path.

3. The heat pump unit according to claim 1, characterized in that, The refrigerant main circuit includes an evaporator, which is located upstream of the electronic expansion valve in the heating phase, and the inlet of the first ejector branch is connected to the evaporator.

4. The heat pump unit according to claim 1, characterized in that, The third ejector branch includes a fourth control valve.

5. The heat pump unit according to claim 1, characterized in that, The inlet of the third ejector branch is connected to the first refrigerant port of the evaporative condenser through the third sub-flow path, and the connection position is located on the side of the first control valve in the third sub-flow path near the first refrigerant port of the evaporative condenser.

6. The heat pump unit according to any one of claims 1-5, characterized in that, The fourth sub-flow path includes a fifth control valve, and the inlet of the third ejector branch is connected to the second refrigerant port of the evaporative condenser through the fourth sub-flow path; Specifically, the inlet of the third ejector branch and the connection point of the fourth sub-flow path are located on the side of the fifth control valve away from the evaporator-condenser, or the inlet of the third ejector branch and the connection point of the fourth sub-flow path are located on the side of the fifth control valve closer to the evaporator-condenser.

7. An air conditioner, characterized in that, The air conditioner includes a heat pump unit as described in any one of claims 1-6.

8. A control method, characterized in that, The control method is applied to the heat pump unit as described in any one of claims 1-6, and the control method includes: When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the first control valve of the heat pump unit is controlled to be closed, and the second and third control valves of the heat pump unit are both controlled to be open, so as to eject the refrigerant in the evaporator-condenser of the heat pump unit into the heating circulation path of the heat pump unit.

9. The control method according to claim 8, characterized in that, The refrigerant circuit of the heat pump unit includes a compressor, and determining that the heat pump unit meets the ejector start-up conditions includes: The discharge pressure Pc of the compressor is determined to satisfy Pc < 650 kPa × [1 + (Q - 25%)]; where Pc is the discharge pressure of the compressor and Q is the load of the compressor.

10. The control method according to claim 9, characterized in that, The step of determining that the heat pump unit meets the ejector start-up conditions also includes: It is determined that the ambient temperature of the heat pump unit is greater than the set temperature threshold.

11. The control method according to claim 8, characterized in that, The control method includes: When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejection exit condition, the first control valve, the second control valve, and the third control valve are all controlled to be closed to prevent the refrigerant in the evaporator-condenser of the heat pump unit from being ejected into the heating circulation path of the heat pump unit.

12. The control method according to claim 11, characterized in that, The determination that the heat pump unit meets the ejector exit conditions includes: The internal pressure of the air-cooled condenser of the heat pump unit and the load of the compressor of the heat pump unit are determined to satisfy Pa < P1 × (Q - 25%) / 65%, and the internal pressure of the evaporative condenser is determined to satisfy Pb < P2; where Pa is the internal pressure of the air-cooled condenser, Pb is the internal pressure of the evaporative condenser, P1 is the first set pressure, P2 is the second set pressure, and Q is the load of the compressor.

13. The control method according to claim 8, characterized in that, The control method includes: When the heat pump unit is in cooling mode, the first control valve is controlled to be in the open state, and the second control valve and the third control valve are controlled to be in the closed state.

14. The control method according to any one of claims 8-13, characterized in that, When the third ejector branch includes a fourth control valve, the control method includes: When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the fourth control valve is controlled to be in the open state. When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector exit conditions, the fourth control valve is controlled to be in the closed state. When the heat pump unit is in cooling mode, the fourth control valve is kept closed.

15. The control method according to any one of claims 8-13, characterized in that, When the fourth sub-flow path includes a fifth control valve, and the inlet of the third ejector branch is connected to the fourth sub-flow path at a position opposite to the evaporative condenser of the fifth control valve, the control method includes: When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector start-up conditions, the fifth control valve is controlled to be in the open state. When the heat pump unit is in heating mode, if it is determined that the heat pump unit meets the ejector exit conditions, the fifth control valve is controlled to be in the closed state.

16. The control method according to any one of claims 8-13, characterized in that, When the fourth sub-flow path includes a fifth control valve, and the inlet of the third ejector branch is connected to the fourth sub-flow path at a position near the evaporative condenser of the fifth control valve, the control method includes: When the heat pump unit is in heating mode, the fifth control valve is kept closed.

17. The control method according to any one of claims 8-13, characterized in that, When the fourth sub-flow path includes a fifth control valve, the control method includes: When the heat pump unit is in cooling mode, after the fifth control valve is opened at an initial opening degree, the opening degree of the fifth control valve is gradually increased until the fifth control valve reaches its maximum opening degree.

18. The control method according to claim 17, characterized in that, The step of gradually increasing the opening of the fifth control valve until the fifth control valve reaches its maximum opening includes: If the internal pressure of the air-cooled condenser of the heat pump unit and the internal pressure of the evaporative condenser satisfy Pb≥Pa-100kPa, then the opening degree of the fifth control valve is increased at the first opening speed; where Pa is the internal pressure of the air-cooled condenser and Pb is the internal pressure of the evaporative condenser.

19. The control method according to claim 18, characterized in that, The step of gradually increasing the opening of the fifth control valve until the fifth control valve reaches its maximum opening includes: If the internal pressure of the air-cooled condenser of the heat pump unit and the internal pressure of the evaporative condenser satisfy Pb < Pa - 100 kPa, then the opening degree of the fifth control valve is increased at a second opening speed; wherein the second opening speed is less than the first opening speed.

Images