Heat pump system and control method

Abstract

The invention belongs to the technical field of heat pumps, and discloses a heat pump system and a control method, hot water prepared by a condenser is adopted to perform defrosting treatment on a water receiving disc, the defrosting effect can be effectively ensured, an electric heater does not need to be arranged, and the cost is reduced. The problem that when an electric heater is used for conducting defrosting treatment, the defrosting function is extremely prone to failure can be effectively solved, and it is guaranteed that the heat pump system can work normally. The reliability is high, and damage is not prone to occurring. When the heat pump system is used as an outdoor product, the evaporator adopts an air heat exchanger. When the hot water prepared by the condenser is used for carrying out defrosting treatment on the water receiving disc, one part of heat energy required for defrosting comes from electric energy, the other part of heat energy comes from air energy, the conversion energy efficiency ratio is far greater than 1, the electric energy required for carrying out defrosting treatment on the water receiving disc is less, and the economic benefit is good.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and in particular to a heat pump system and control method. Background Technology

[0002] Heat pump water heaters or heat pump heating units have a drip tray below the evaporator. Water vapor in the air is cooled as it passes through the evaporator, forming water droplets that fall into the drip tray. When the ambient temperature is low, frost will form on the surface of the evaporator, and the defrosting water generated during the defrosting process will also drip into the drip tray.

[0003] When the low-temperature environment lasts for a long time, more and more ice will accumulate in the drip tray, which will lead to poor drainage and seriously affect the efficiency of the heat pump.

[0004] One solution proposed in the existing technology is to install an electric heating belt on the water receiving pan. When it is necessary to defrost the water receiving pan, the electric heating belt is energized, and the electric heating belt heats up to defrost the water receiving pan.

[0005] However, heat pump water heaters or heat pump heating units are mostly installed outdoors. Due to the long-term exposure to wind, sun, rain, and snow, the electric heating element is easily damaged and leaks electricity, causing the defrosting function of the heat pump to fail.

[0006] Furthermore, in extremely cold environments, such as when the ambient temperature is no higher than -30°C, the amount of heat required for defrosting using an electric heating element connected to the water pan is very small. This requires the electric heating element to work for an extended period of time, resulting in poor defrosting performance. Consequently, the heating capacity of the heat pump water heater or heat pump heating unit drops rapidly, and in severe cases, it may even cease to function.

[0007] Another proposed solution in the existing technology is to set up two condensers, one of which is used to heat water, and the other is set below the water tray. When defrosting is required, both condensers participate in the heating cycle to achieve defrosting. However, in this defrosting method, some refrigerant will not participate in heating during the heating process, and the temperature of this part of the refrigerant after defrosting is relatively high, which can easily lead to high compressor return gas temperature, thereby affecting the heat pump efficiency.

[0008] Therefore, there is still room for improvement in existing heat pump defrosting technology. Summary of the Invention

[0009] One of the technical problems solved by this invention is to provide a heat pump system that can effectively guarantee defrosting, thereby ensuring the normal operation of the heat pump system and reducing energy consumption.

[0010] One of the technical problems solved by this invention is to provide a heat pump system control method that has good defrosting effect and low energy consumption.

[0011] The first technical problem mentioned above is solved by the following technical solution:

[0012] A heat pump system includes a compressor, a condenser, a main expansion valve, and an evaporator connected in series to form a heat exchange loop, wherein the condenser has a hot water passage; the heat pump system further includes:

[0013] A drip tray, located at the bottom of the evaporator, is used to collect water dripping from the surface of the evaporator.

[0014] The defrosting structure has a defrosting chamber, and the hot water channel is connected to the defrosting chamber to form a defrosting circulation loop. The hot water flowing in the defrosting chamber is used to defrost the water receiving tray.

[0015] A defrosting valve is installed in the defrosting circulation loop, and the defrosting valve can control the on / off state of the defrosting circulation loop.

[0016] The heat pump system described in this invention has the following advantages compared to the prior art:

[0017] Using hot water generated by the condenser to connect to the water pan for defrosting can effectively ensure the defrosting effect, and it eliminates the need for an electric heater. This effectively solves the problem that the defrosting function is prone to failure when using an electric heater for defrosting, ensuring that the heat pump system can work normally. Moreover, it has high reliability and is not easily damaged.

[0018] When a heat pump system is used as an outdoor product, an air heat exchanger is used as the evaporator. When hot water prepared by the condenser is connected to the water pan for defrosting, the heat energy required for defrosting comes partly from electricity and partly from air energy. The energy efficiency ratio is much greater than 1, and less electricity is required for defrosting the water pan, resulting in good economic benefits.

[0019] This heat pump system requires only one condenser, reducing costs and space requirements. All refrigerant in the system participates in the heating cycle, effectively solving the problem of high compressor return gas temperature caused by some refrigerant not participating in the heating cycle when using two condensers in existing technologies, thus improving the system's efficiency.

[0020] In one embodiment, the top of the defrosting structure forms the water receiving tray, and the defrosting chamber is provided with a guide plate that divides the defrosting chamber into a first sub-chamber and a second sub-chamber. One end of the first sub-chamber is connected to the return water inlet of the hot water channel, and the other end is connected to the second sub-chamber. The supply water inlet of the hot water channel is connected to the second sub-chamber. The position where the water receiving tray contacts the bottom of the evaporator is the contact position, and the first sub-chamber is correspondingly located directly below the contact position.

[0021] Alternatively, the defrosting structure may be a heat exchange coil, with a portion of the heat exchange coil disposed between the water receiving pan and the bottom of the evaporator, and in contact with the bottom of the evaporator.

[0022] In one embodiment, the defrosting valve is a two-position four-way valve, which has a defrosting state and an idle state. When the two-position four-way valve is in the defrosting state, the water supply port of the hot water channel is connected to the defrosting inlet of the defrosting chamber, and the water return port of the hot water channel is connected to the defrosting outlet of the defrosting chamber. When the two-position four-way valve is in the idle state, the water supply port of the hot water channel is disconnected from the defrosting inlet of the defrosting chamber, and the water return port of the hot water channel is disconnected from the defrosting outlet of the defrosting chamber.

[0023] Alternatively, the defrosting valve includes an inlet valve and a return valve, wherein the water supply port of the hot water channel is connected to the defrosting inlet of the defrosting chamber through the inlet valve, and the return port of the hot water channel is connected to the defrosting outlet of the defrosting chamber through the return valve.

[0024] In one embodiment, the heat pump system further includes:

[0025] A water supply temperature detection unit is used to detect the water temperature at the water supply port of the hot water channel;

[0026] A defrosting temperature detection unit is used to detect the temperature inside the defrosting chamber;

[0027] And / or, the heat pump system further includes:

[0028] The heating return water temperature detection unit is provided. The return water inlet of the hot water channel is connected to the heating return water pipe. The heating return water pipe is connected to the defrost outlet of the defrost chamber at a first preset position. Along the water flow direction in the heating return water pipe, the heating return water temperature detection unit is located upstream of the first preset position.

[0029] In one embodiment, the defrosting structure has a defrosting drain outlet communicating with the defrosting chamber, and the defrosting drain outlet is provided with a drain switch valve;

[0030] And / or, the water receiving tray is provided with a water receiving and drain outlet for discharging the water in the water receiving tray into the external environment.

[0031] The second technical problem mentioned above is solved by the following technical solution:

[0032] A heat pump system control method, used in any of the heat pump systems provided in the above embodiments, the heat pump system control method comprising:

[0033] Upon receiving a defrosting start command, the defrosting valve is controlled to activate the defrosting circulation loop.

[0034] Compared with the prior art, the heat pump system control method of the present invention has the following advantages:

[0035] When water flows through the defrosting chamber in the defrosting circulation loop, it can transfer heat to the water tray to melt the frost in the water tray; there is no need to install an electric heater, which can effectively solve the problem that the defrosting function is prone to failure when using an electric heater for defrosting, and ensure that the heat pump system can work normally; moreover, it has high reliability and low power consumption.

[0036] In one embodiment, when the defrosting function is turned off, the defrosting valve is controlled to disconnect the defrosting circulation loop.

[0037] The defrosting function is turned off under the following conditions: receiving a user-inputted end command; or, the temperature difference between the water supply outlet temperature of the hot water channel and the temperature inside the defrosting chamber is less than a preset end temperature difference; or, the duration of defrosting exceeds a preset defrosting duration.

[0038] In one embodiment, when the temperature in the defrosting chamber is lower than the preset drainage temperature, the drainage switch valve is controlled to drain the water from the defrosting chamber.

[0039] And when the drainage duration reaches the preset drainage duration, the drainage switch valve is controlled to stop drainage.

[0040] In one embodiment, the heat pump system control method further includes:

[0041] Obtain the heating return water temperature at a second preset position within the heating return water pipe. Along the water flow direction within the heating return water pipe, the second preset position is located upstream of the first preset position of the defrost outlet of the heating return water pipe that connects to the defrost chamber.

[0042] When the heating return water temperature is lower than the preset minimum return water temperature, determine whether the compressor's operating power has reached the preset maximum power.

[0043] If the operating power of the compressor does not reach the preset maximum power, the power of the compressor is increased; if the operating power of the compressor reaches the preset maximum power, the opening degree of the defrosting circulation loop is decreased.

[0044] The continuity of the defrosting circulation loop includes the connection between the water supply port of the hot water channel and the defrosting inlet of the defrosting chamber, and / or the connection between the return port of the hot water channel and the defrosting outlet of the defrosting chamber.

[0045] In one embodiment, before reducing the conduction opening of the defrosting circulation loop, the method further includes: determining whether the conduction opening of the defrosting circulation loop is greater than a preset minimum opening.

[0046] If the conduction opening of the defrosting circulation loop is greater than the preset minimum opening, then the conduction opening of the defrosting circulation loop shall be reduced.

[0047] If the opening degree of the defrosting circulation loop is not greater than the preset minimum opening degree, then the opening degree of the defrosting circulation loop is controlled to be maintained at the preset minimum opening degree. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of a heat pump system provided in one embodiment of the present invention;

[0049] Figure 2 This is a partial structural schematic diagram of the heat pump system provided in an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of a heat pump system provided in another embodiment of the present invention;

[0051] Figure 4 This is a flowchart of a heat pump system control method provided in an embodiment of the present invention.

[0052] In the picture:

[0053] 1. Compressor; 2. Condenser;

[0054] 31. Main expansion valve; 32. Auxiliary expansion valve;

[0055] 4. Evaporator;

[0056] 51. Water tray; 52. De-icing structure; 521. De-icing chamber; 5211. First sub-chamber; 5212. Second sub-chamber; 53. Water inlet / outlet;

[0057] 6. Defrosting valve; 61. Inlet valve; 62. Return valve;

[0058] 8. Water supply temperature detection unit; 9. Defrosting temperature detection unit; 10. Drain switch valve; 20. Flow deflector; 30. Economizer; 40. Four-way valve. Detailed Implementation

[0059] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0060] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0062] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0063] Embodiments of the present invention provide a heat pump system that can extend the service life of the heat pump system while ensuring defrosting effect. This heat pump system can be used as a heat pump water heater or as a heat pump heating unit. Exemplarily, the heat pump system is used as a heat pump heating unit.

[0064] like Figure 1 and Figure 2 As shown, the heat pump system includes a compressor 1, a condenser 2, a main expansion valve 31, and an evaporator 4 connected in series to form a heat exchange circulation loop. The heat pump system also includes a water tray 51, a defrosting structure 52, and a defrosting valve 6. The water tray 51 is located at the bottom of the evaporator 4 and is used to collect water dripping from the surface of the evaporator 4. The defrosting structure 52 has a defrosting chamber 521. A hot water channel is connected to the defrosting chamber 521 to form a defrosting circulation loop. The hot water flowing in the defrosting chamber 521 is used to defrost the water tray 51. The defrosting valve 6 is located in the defrosting circulation loop and can control the opening and closing of the defrosting circulation loop.

[0065] Specifically, the return water inlet of the hot water channel is connected to the defrost outlet of the defrost chamber 521, and the supply water inlet of the hot water channel is connected to the defrost inlet of the defrost chamber 521 to form a defrost circulation loop.

[0066] The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the condenser 2. The refrigerant condenses and releases heat in the condenser 2, which heats the water flowing in the hot water channel of the condenser 2. After that, the refrigerant passes through the main expansion valve 31 and enters the evaporator 4 to absorb heat. Then it is drawn into the compressor 1, realizing the circulation of the refrigerant in the heat exchange loop and completing the heating cycle of the heat pump system.

[0067] During the heating cycle of the heat pump system, if ice forms in the water tray 51 and defrosting is required, the defrosting valve 6 is controlled to open the defrosting circulation loop. The hot water flowing out of the hot water channel of the condenser 2 enters the defrosting chamber 521. The hot water in the defrosting chamber 521 transfers heat to the water tray 51, raising its temperature and thus defrosting the water tray 51. After cooling down in the defrosting chamber 521, the hot water returns to the hot water channel of the condenser 2.

[0068] Using the hot water prepared by the condenser 2 to connect to the water pan 51 for defrosting can effectively ensure the defrosting effect. Moreover, there is no need to install an electric heater, which can effectively solve the problem that the defrosting function is prone to failure when using an electric heater for defrosting, and ensure that the heat pump system can work normally.

[0069] When the heat pump system is used as an outdoor product, the evaporator 4 employs an air heat exchanger. When the hot water generated by the condenser 2 is connected to the water pan 51 for defrosting, the heat energy required for defrosting comes partly from electricity and partly from air energy, resulting in a conversion efficiency ratio far greater than 1. Therefore, the amount of electricity required for defrosting the water pan 51 is relatively small. In contrast, when the existing technology uses an electric heating element connected to the water pan 51 for defrosting, all the heat energy required for defrosting the water pan 51 comes from electricity, resulting in a conversion efficiency ratio less than 1. Therefore, the heat pump system of this invention offers better economic benefits when defrosting the water pan 51.

[0070] In existing technologies, when using electric heaters for defrosting, a 75-watt electric heating element is typically used, which generates very little heat. Even if the power of the electric heating element is increased to 1000 watts, the resulting heat is insufficient to completely remove frost or ice from the drip tray 51 in extremely low temperatures. As more and more ice accumulates on the drip tray 51, it easily affects the normal heat exchange of the evaporator 4 and severely impacts the operation of the heat exchange fan used for heat exchange with the evaporator 4, especially during freezing rain, which significantly accelerates the damage to the heat pump system. In contrast, the heat pump system of this invention uses hot water heated by the condenser 2 to defrost the drip tray 51. This heat energy is essentially equivalent to the heating capacity of the heat pump system. For example, a 5-horsepower heat pump system has a heating capacity of 12 kilowatts, which is 160 times that of a 75-watt system. This allows for the complete removal of frost or ice from the drip tray 51, resulting in excellent defrosting performance, high reliability, and less susceptibility to damage.

[0071] This heat pump system requires only one condenser 2, reducing costs and space requirements. The refrigerant in the heat pump system fully participates in the heating cycle, effectively solving the problem of high compressor return gas temperature caused by some refrigerant not participating in the heating cycle when two condensers are used in existing technologies, thus improving the efficiency of the heat pump system.

[0072] In some embodiments, a water collection tray 51 is formed at the top of the defrosting structure 52, thereby integrating the water collection tray 51 into the defrosting structure 52. This simplifies the structure of the heat pump system, reduces costs, improves the integration level of the heat pump system, and reduces the space occupied by the heat pump system.

[0073] For example, the defrosting structure 52 adopts a box structure, the inner cavity of the box structure forms the aforementioned defrosting chamber 521, and the top plate of the box structure forms a water collection tray 51. Specifically, the defrosting structure 52 includes a box body with a top opening and a cover plate that is sealed to the box body to block the top opening. The cover plate is the aforementioned water collection tray 51. As for the connection method between the box body and the cover plate, it can be a snap-fit ​​or a fastener connection, and a seal is provided between the box body and the cover plate to prevent water leakage.

[0074] In some embodiments, such as Figure 1 and Figure 2 As shown, a defrosting pump is installed on the defrosting circulation loop.

[0075] During the heating cycle of the heat pump system, if ice forms in the water tray 51 and defrosting is required, the defrosting valve 6 is controlled to open the defrosting circulation loop and the defrosting pump is activated. After the hot water cools down in the defrosting chamber 521, it returns to the hot water channel of the condenser 2 for heat exchange and reheating. This allows the hot water produced by the condenser 2 to continuously enter the defrosting chamber 521, while the water in the defrosting chamber 521, cooled down after defrosting, continuously returns to the hot water channel of the condenser 2. This significantly shortens the time required for defrosting the water tray 51 and improves the efficiency of ice melting in the water tray 51.

[0076] It should be noted that the defrosting pump can be a pump used in an existing heat pump system to deliver the hot water prepared by the condenser 2 to the user end. In this case, the pump can be installed at the water supply port of the hot water channel to reduce the number of parts in the heat pump system and reduce costs. Alternatively, the defrosting pump can be a pump added to an existing heat pump system. In this case, the defrosting pump can be installed at the defrosting inlet of the defrosting chamber 521, or on the connecting pipe between the defrosting outlet of the defrosting chamber 521 and the return port of the hot water channel.

[0077] In some embodiments, such as Figure 2 As shown, the defrost outlet is located at the top of the defrost structure 52. This arrangement allows the water in the defrost chamber 521 to flow back into the hot water channel through the defrost outlet after the chamber is filled with hot water. This facilitates the rapid transfer of heat from the hot water in the defrost chamber 521 to the water receiving tray 51, improving heat transfer efficiency and heat exchange effect.

[0078] In some embodiments, the supply inlet of the hot water channel is used to provide hot water to users, such as for heating and / or for domestic hot water, and the return inlet of the hot water channel serves as the return inlet for heating and / or domestic hot water. This configuration allows the entire heat pump system to use only one condenser 2, which is used to produce heating hot water and / or domestic hot water, as well as hot water for defrosting, reducing the number of components in the heat pump system and lowering its cost.

[0079] In some embodiments, such as Figure 1 and Figure 2 As shown, the defrosting valve 6 includes an inlet valve 61 and a return valve 62. The water supply port of the hot water channel is connected to the defrosting inlet of the defrosting chamber 521 through the inlet valve 61, and the return port of the hot water channel is connected to the defrosting outlet of the defrosting chamber 521 through the return valve 62.

[0080] For example, both the inlet valve 61 and the return valve 62 are electromagnetic switching valves. During defrosting, the inlet valve 61 is energized to connect the hot water supply port of the hot water channel to the defrosting inlet of the defrosting chamber 521, and the return valve 62 is energized to connect the hot water return port of the hot water channel to the defrosting outlet of the defrosting chamber 521. When the defrosting process ends, the inlet valve 61 is de-energized to disconnect the hot water supply port of the hot water channel from the defrosting inlet of the defrosting chamber 521, and the return valve 62 is de-energized to disconnect the hot water return port of the hot water channel from the defrosting outlet of the defrosting chamber 521.

[0081] In other embodiments, the defrosting valve 6 may also be a two-position four-way valve, which has a defrosting state and an idle state. When the two-position four-way valve is in the defrosting state, the water supply port of the hot water channel is connected to the defrosting inlet of the defrosting chamber 521 and the water return port of the hot water channel is connected to the defrosting outlet of the defrosting chamber 521. When the two-position four-way valve is in the idle state, the water supply port of the hot water channel is disconnected from the defrosting inlet of the defrosting chamber 521 and the water return port of the hot water channel is disconnected from the defrosting outlet of the defrosting chamber 521.

[0082] Specifically, the inlet of the two-position four-way valve is connected to the supply port of the hot water channel, the return port of the two-position four-way valve is connected to the return port of the hot water channel, the first working port of the two-position four-way valve is connected to the defrost inlet of the defrost chamber 521, and the second working port of the two-position four-way valve is connected to the defrost outlet of the defrost chamber 521.

[0083] When the two-position four-way valve is in the defrosting state, the inlet of the four-way valve is connected to the first working port of the two-position four-way valve, and the return port of the two-position four-way valve is connected to the second working port of the two-position four-way valve, so that the defrosting circulation loop is opened.

[0084] When the two-position four-way valve is idle, the inlet of the four-way valve is disconnected from the first working port of the two-position four-way valve, and the return port of the two-position four-way valve is disconnected from the second working port of the two-position four-way valve, thus disconnecting the defrosting circulation loop.

[0085] In some embodiments, such as Figure 1 and Figure 2 As shown, a guide plate 20 is provided inside the defrosting chamber 521. The guide plate 20 divides the defrosting chamber 521 into a first sub-chamber 5211 and a second sub-chamber 5212. One end of the first sub-chamber 5211 is connected to the return water inlet of the hot water channel, and the other end is connected to the second sub-chamber 5212. The water supply inlet of the hot water channel is connected to the second sub-chamber 5212. The position where the water receiving tray 51 contacts the bottom of the evaporator 4 is the contact position, and the first sub-chamber 5211 is correspondingly located directly below the contact position.

[0086] The hot water prepared by the condenser 2 first enters the second sub-chamber 5212 to melt the frost in the water pan 51, and then enters the first sub-chamber 5211. The evaporator 4 will absorb the heat energy in the second sub-chamber 5212 to improve the efficiency of the heat pump and thus obtain a higher energy efficiency ratio.

[0087] The shape of the first sub-chamber 5211 is the same as the contact surface shape between the defrosting structure 52 and the evaporator 4, and the contact surface shape between the defrosting structure 52 and the evaporator 4 is the bottom surface shape of the evaporator 4. For example, the contact surface between the defrosting structure 52 and the evaporator 4 is L-shaped, and the first sub-chamber 5211 is an L-shaped chamber. It should be noted that when the bottom surface shape of the evaporator 4 is other shapes, the first sub-chamber 5211 of a corresponding shape is adaptively provided.

[0088] For example, both the defrost inlet and the defrost outlet are located on the water receiving tray 51, so that the defrost inlet and the defrost outlet can be connected to the water supply and return outlet of the hot water channel respectively through pipes. In other embodiments, the defrost inlet and the defrost outlet can also be located on the defrost structure 52.

[0089] For example, one end of the first sub-chamber 5211 is connected to one end of the second sub-chamber 5212 at one end of the length direction of the evaporator 4, and the end of the second sub-chamber 5212 connected to the hot water channel and the end of the first sub-chamber 5211 connected to the hot water channel are both located at the other end of the length direction of the evaporator 4, so as to extend the flow path of hot water in the second sub-chamber 5212 and the first sub-chamber 5211 and improve the heat transfer effect.

[0090] In other embodiments, the defrosting structure 52 can also be a heat exchange coil. The defrosting structure 52 is a heat exchange coil, and part of the heat exchange coil is set between the water receiving pan 51 and the bottom of the evaporator 4, and is set in contact with the bottom of the evaporator 4. The hot water flowing in the heat exchange coil is used to defrost the water receiving pan 51, and the evaporator 4 further absorbs the heat in the heat exchange coil, so as to make full use of the heat energy of the hot water flowing in the heat exchange coil.

[0091] Another part of the heat exchange coil can be set inside the water receiving pan 51 and in contact with the water receiving pan 51, or the heat exchange coil can be set below the water receiving pan 51 and in contact with the water receiving pan 51, or the heat exchange coil can be wrapped around the outer periphery of the water receiving pan 51.

[0092] In some embodiments, the circumferential sidewalls and bottom wall of the defrosting structure 52 are covered with an insulation layer to insulate the defrosting structure 52 and prevent excessive heat from escaping into the air. For example, the insulation layer is insulating cotton.

[0093] In some embodiments, such as Figure 1 and Figure 2 As shown, the defrosting structure 52 has a defrosting drain port that communicates with the defrosting chamber 521, and the defrosting drain port is equipped with a drain switch valve 10.

[0094] After defrosting the water tray 51, opening the drain valve 10 allows the water in the defrosting chamber 521 to be completely discharged from the heat pump system through the defrosting drain port, thus preventing the water in the defrosting chamber 521 from freezing as the temperature subsequently decreases, ensuring high safety performance.

[0095] For example, the drain switch valve 10 is an electromagnetic switch valve. When the drain switch valve 10 is energized, water in the defrost chamber 521 is discharged from the heat pump system through the defrost drain port; when the drain switch valve 10 is de-energized, water in the defrost chamber 521 cannot be discharged through the defrost drain port.

[0096] In some embodiments, a balancing valve is provided on the top of the defrosting structure 52. When the inlet valve 61 and the return valve 62 are opened and the drain valve 10 is closed, the air in the defrosting chamber 521 can be discharged to the outside atmosphere through the balancing valve, so that hot water can be normally injected into the defrosting chamber 521. When the inlet valve 61 and the return valve 62 are closed and the drain valve 10 is opened, outside air can enter the defrosting chamber 521 through the exhaust valve, so that the water in the defrosting chamber 521 can be discharged to the outside through the drain valve 10.

[0097] In some embodiments, such as Figure 1 and Figure 2 As shown, the water tray 51 is provided with a water drain outlet 53. Water in the water tray 51, such as rainwater, snow water, defrost water, de-icing water, and condensate dripping from the surface of the evaporator 4 into the water tray 51, can be completely discharged out of the heat pump system through the water drain outlet 53.

[0098] In some embodiments, the water inlet 53 is located at the lowest position on the upper surface of the water receiving tray 51 so that water in the water receiving tray 51 can be discharged through the water inlet 53 in a timely manner.

[0099] In some embodiments, such as Figure 1 and Figure 2 As shown, the heat pump system also includes an economizer 30, which has an evaporation channel and a condensation channel. The evaporation channel is connected to the heat exchange loop between the condenser 2 and the main expansion valve 31. The inlets of the condenser 2 and the compressor 1 are connected through a vapor injection enthalpy-increasing pipeline. An auxiliary expansion valve 32 is installed on the vapor injection enthalpy-increasing pipeline. The condensation channel is connected between the outlet of the auxiliary expansion valve 32 and the inlet of the compressor 1.

[0100] In some embodiments, such as Figure 3As shown, the heat pump system also includes a four-way valve 40, which has ports A, B, C, and D. Port A is connected to the outlet of compressor 1, port B is connected to the condensing channel of condenser 2, port C is connected to the inlet of compressor 1, and port D is connected to the evaporating channel of evaporator 4. When the heat pump system is in heating mode, ports A and B are connected, and ports C and D are connected; when the heat pump system is in cooling mode, ports A and D are connected, and ports B and C are connected.

[0101] Embodiments of the present invention also provide a heat pump system control method for use in any of the heat pump systems provided in the above embodiments.

[0102] The heat pump system control method includes the following steps:

[0103] Upon receiving the defrosting start command, the defrosting valve 6 is controlled to open the defrosting circulation loop.

[0104] When water flows through the defrosting chamber 521 in the defrosting circulation loop, it can transfer heat to the water receiving tray 51, so that the frost in the water receiving tray 51 melts.

[0105] It should be noted that the defrosting pump operates when the defrosting valve 6 opens the defrosting circulation loop; if the defrosting pump is a separately added defrosting pump, it stops operating when the defrosting valve 6 disconnects the defrosting circulation loop; if the defrosting pump is a pump used in the existing heat pump system to deliver the hot water prepared by the condenser 2 to the user, it starts and stops according to the user's hot water preparation needs when the defrosting valve 6 disconnects the defrosting circulation loop.

[0106] In some embodiments, upon receiving a user-inputted end command; or when the temperature difference between the hot water supply outlet temperature and the temperature inside the defrosting chamber 521 is less than a preset end temperature difference; or when the defrosting duration exceeds a preset defrosting duration, the defrosting valve 6 is controlled to disconnect the defrosting circulation loop. In other words, the defrosting valve 6 is controlled to disconnect the defrosting circulation loop when any of the above three conditions are met.

[0107] It should be noted that the aforementioned preset end temperature difference is a known value determined based on multiple repeated tests. When the temperature difference between the water at the water supply outlet and the temperature inside the defrosting chamber 521 is less than the preset end temperature difference, it indicates that the temperature drop inside the defrosting chamber 521 is significant, and the frost and ice in the water tray 51 have been largely cleared. Continuing to defrost the water tray 51 can then be stopped. The aforementioned preset defrosting time is determined based on multiple repeated tests, assuming a fixed volume of the defrosting chamber 521 and a maximum amount of ice in the water tray 51. Different volumes of the defrosting chamber 521 will directly affect the defrosting time. The aforementioned preset end temperature difference and preset defrosting time are pre-embedded in the heat pump system controller.

[0108] Specifically, the heat pump system also includes a water supply temperature detection unit 8 and a defrost temperature detection unit 9. The water supply temperature detection unit 8 is used to detect the water temperature at the water supply outlet; the defrost temperature detection unit 9 is used to detect the temperature inside the defrost chamber 521. For example, both the water supply temperature detection unit 8 and the defrost temperature detection unit 9 are temperature sensors and are electrically connected to the controller of the heat pump system. The controller can receive the detection signals from the water supply temperature detection unit 8 and the defrost temperature detection unit 9, and obtain the water temperature at the water supply outlet and the temperature inside the defrost chamber 521 based on the acquired detection signals.

[0109] The aforementioned defrosting temperature detection unit 9 is used to detect the water temperature in the second sub-chamber 5212. In order to accurately determine the end time of stopping defrosting, the connection position between the second sub-chamber 5212 and the first sub-chamber 5211 is closer to the defrosting temperature detection unit 9 than the defrosting inlet.

[0110] In some embodiments, the defrosting start command includes a start command input by the user, and / or a defrosting start command generated when the temperature in the second sub-chamber 5212 is not higher than a preset start temperature.

[0111] The heat pump system is equipped with a display or a start button, allowing users to input a defrosting start command by operating the display or pressing the start button. For example, the preset start temperature is a known value determined through repeated testing and pre-embedded in the heat pump system's controller; the preset start temperature is less than 5°C. When the temperature in the second sub-chamber 5212 is not higher than the preset start temperature, the temperature inside the second sub-chamber 5212 is essentially the ambient temperature, indicating that freezing or frost has likely occurred in the water tray 51, requiring defrosting.

[0112] In some embodiments, when the temperature inside the defrosting chamber 521 is lower than the preset drainage temperature, the drain switch valve 10 is controlled to drain the water inside the defrosting chamber 521; and when the drainage duration reaches the preset drainage duration, the drain switch valve 10 is controlled to stop the drainage.

[0113] The preset drainage temperature is determined through repeated tests. For example, any temperature value within the range of 2℃ < preset drainage temperature < 6℃. After defrosting stops, if the temperature inside the defrosting chamber 521 is lower than the preset drainage temperature, it indicates that the water inside the defrosting chamber 521 is at risk of freezing. Therefore, the drain valve 10 is opened to drain the water from the defrosting chamber 521 to the outside of the heat pump system. The preset drainage duration is related to the volume of the defrosting chamber 521. Given a fixed volume, the preset drainage duration is determined through repeated tests and pre-embedded in the heat pump system controller. When the drainage duration reaches the preset drainage duration, it indicates that the defrosting chamber 521 has been completely drained, and further drainage can be stopped.

[0114] In some embodiments, the return inlet of the hot water channel is connected to a heating return water pipe, and the supply inlet of the heating channel is connected to a heating supply water pipe. The heating hot water prepared by the condenser 2 is sent to the heating equipment through the heating supply water pipe, and the low-temperature heating water flowing out of the heating equipment returns to the condenser 2 through the heating return water pipe. The heating equipment is used to meet the user's heating needs.

[0115] The heating return water pipe is connected to the defrost outlet of the defrost chamber 521 at the first preset position. The low-temperature heating water in the heating return water pipe merges with the low-temperature water returning from the first preset position and the defrost chamber 521 and flows into the hot water channel.

[0116] The heat pump system also includes a heating return water temperature detection unit, which is located upstream of a first preset position along the water flow direction within the heating return water pipe. The heating return water temperature is detected by the heating return water temperature detection unit. For example, the heating return water temperature detection unit is a temperature sensor.

[0117] In some embodiments, the heat pump system control method further includes the following steps:

[0118] Obtain the heating return water temperature at the second preset position inside the heating return water pipe;

[0119] When the heating return water temperature is lower than the preset minimum return water temperature, determine whether the operating power of compressor 1 has reached the preset maximum power;

[0120] If the operating power of compressor 1 does not reach the preset maximum power, then increase the power of compressor 1; if the operating power of compressor 1 reaches the preset maximum power, then decrease the opening degree of the defrosting circulation loop.

[0121] Along the water flow direction within the heating return water pipe, the second preset position is located upstream of the first preset position of the defrost outlet of the defrost chamber 521, which connects to the heating return water pipe. In other words, the heating return water temperature detection unit is located at the aforementioned second preset position.

[0122] The opening degree of the defrosting circulation loop includes the connection degree between the hot water supply port of the hot water channel and the defrosting inlet of the defrosting chamber 521, and / or the connection degree between the hot water return port of the hot water channel and the defrosting outlet of the defrosting chamber 521. For example, the inlet valve 61 is an adjustable flow regulating valve; when it is necessary to reduce the opening degree of the defrosting circulation loop, the opening degree of the inlet valve 61 can be reduced.

[0123] When the heating return water temperature is lower than the preset minimum return water temperature, it indicates that the heating water provided by the condenser 2 cannot meet the heating needs of the heating equipment. If the operating power of the compressor 1 does not reach the preset maximum power, the operating power of the compressor 1 should be increased first to send hot water at a higher temperature to the heating equipment, so as to meet the heating needs of the heating equipment and the heat energy needs of the water pan 51 for defrosting as much as possible. If the operating power of the compressor 1 reaches the preset maximum power, it indicates that it cannot meet the heating needs of the heating equipment and the heat energy needs of the water pan 51 for defrosting at the same time. In this case, the opening of the defrosting circulation loop should be reduced to reduce the amount of hot water sent to the defrosting chamber 521, so as to send more hot water to the heating equipment and preferably meet the heating needs of the heating equipment.

[0124] It should be noted that the preset minimum return water temperature is a known value determined through repeated experiments.

[0125] In some embodiments, before reducing the conduction opening of the defrosting circulation loop, the method further includes: determining whether the conduction opening of the defrosting circulation loop is greater than a preset minimum opening.

[0126] If the opening degree of the defrosting circulation loop is greater than the preset minimum opening degree, then the opening degree of the defrosting circulation loop is reduced; if the opening degree of the defrosting circulation loop is not greater than the preset minimum opening degree, then the opening degree of the defrosting circulation loop is controlled to be maintained at the preset minimum opening degree.

[0127] If the compressor 1 operates at its preset maximum power, it cannot simultaneously meet the heating needs of the heating equipment and the heat energy requirements for defrosting the water pan 51. In this case, it is first determined whether the opening of the defrosting circulation loop is greater than the preset minimum opening. If the opening of the defrosting circulation loop is greater than the preset minimum opening, the opening of the defrosting circulation loop can be reduced to prioritize meeting the heating needs of the heating equipment and reduce the defrosting speed of the water pan 51. If the opening of the defrosting circulation loop is not greater than the preset minimum opening, the opening of the defrosting circulation loop is controlled to remain at the preset minimum opening to reduce the defrosting speed of the water pan 51 while ensuring that the defrosting work of the water pan 51 can continue.

[0128] It should be noted that the preset maximum power is the maximum allowable power of compressor 1 during operation, and the preset minimum opening is a known value determined through repeated tests. The preset minimum opening is the minimum opening allowed for defrosting of the water pan 51. If the opening of the defrosting circulation loop is less than the preset minimum opening, the defrosting speed of the water pan 51 will be too low, which will seriously affect the normal operation of the heat pump system and increase the energy consumption of the heat pump system.

[0129] The heat pump system control method provided in the embodiments of the present invention has two automatic defrosting modes and a manual defrosting mode, which are described below in conjunction with... Figure 4 The workflow of a heat pump system control method according to an embodiment of the present invention will be described.

[0130] S1. Upon receiving the defrosting start command, control the inlet valve 61 and return valve 62 to open, so as to connect the defrosting circulation loop and close the drain switch valve 10.

[0131] S2. Determine if the defrosting function is turned off. If yes, proceed to S3; otherwise, proceed to S4.

[0132] S3. Control the defrosting valve 6 to disconnect the defrosting circulation loop, and then execute S9;

[0133] S4. Obtain the heating return water temperature at the second preset position in the heating return water pipe;

[0134] S5. Determine if the heating return water temperature is lower than the preset minimum return water temperature. If yes, proceed to S6; otherwise, return to S2.

[0135] S6. Determine whether the operating power of compressor 1 has reached the preset maximum power. If not, proceed to S7; if yes, proceed to S8.

[0136] S7. Increase the power of compressor 1 and return to S2;

[0137] S8. Determine whether the conduction opening of the defrosting circulation loop is greater than the preset minimum opening; if yes, proceed to S9; if no, proceed to S10.

[0138] S9. Reduce the opening of the defrosting circulation loop and return to S2;

[0139] S10. Control the opening degree of the defrosting circulation loop to maintain at the preset minimum opening degree, and then return to S2;

[0140] S11. When the temperature inside the defrosting chamber 521 is lower than the preset drainage temperature, open the drainage switch valve 10 to drain the water inside the defrosting chamber 521; and when the drainage duration reaches the preset drainage duration, close the drainage switch valve 10 to stop drainage.

[0141] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A heat pump system comprising a compressor (1), a condenser (2), a main expansion valve (31), and an evaporator (4) connected in series to form a heat exchange circulation loop, wherein the condenser (2) has a hot water passage; characterized in that, The heat pump system also includes: A drip tray (51) is provided at the bottom of the evaporator (4) to collect water dripping from the surface of the evaporator (4); The defrosting structure (52) has a defrosting chamber (521), the hot water channel is connected to the defrosting chamber (521) and forms a defrosting circulation loop, and the hot water flowing in the defrosting chamber (521) is used to defrost the water receiving tray (51). A defrosting valve (6) is provided in the defrosting circulation loop, and the defrosting valve (6) can control the on / off state of the defrosting circulation loop.

2. The heat pump system according to claim 1, characterized in that, The top of the defrosting structure (52) forms the water receiving tray (51). The defrosting chamber (521) is provided with a guide plate (20). The guide plate (20) divides the defrosting chamber (521) into a first sub-chamber (5211) and a second sub-chamber (5212). One end of the first sub-chamber (5211) is connected to the return water inlet of the hot water channel, and the other end is connected to the second sub-chamber (5212). The water supply inlet of the hot water channel is connected to the second sub-chamber (5212). The position where the water receiving tray (51) contacts the bottom of the evaporator (4) is the contact position. The first sub-chamber (5211) is correspondingly located directly below the contact position. Alternatively, the defrosting structure (52) may be a heat exchange coil, with a portion of the heat exchange coil disposed between the water receiving pan (51) and the bottom of the evaporator (4), and in contact with the bottom of the evaporator (4).

3. The heat pump system according to claim 1, characterized in that, The defrosting valve (6) is a two-position four-way valve. The two-position four-way valve has a defrosting state and an idle state. When the two-position four-way valve is in the defrosting state, the water supply port of the hot water channel is connected to the defrosting inlet of the defrosting chamber (521), and the water return port of the hot water channel is connected to the defrosting outlet of the defrosting chamber (521). When the two-position four-way valve is in the idle state, the water supply port of the hot water channel is disconnected from the defrosting inlet of the defrosting chamber (521), and the water return port of the hot water channel is disconnected from the defrosting outlet of the defrosting chamber (521). Alternatively, the defrosting valve (6) includes an inlet valve (61) and a return valve (62). The water supply port of the hot water channel is connected to the defrosting inlet of the defrosting chamber (521) through the inlet valve (61), and the return port of the hot water channel is connected to the defrosting outlet of the defrosting chamber (521) through the return valve (62).

4. The heat pump system according to any one of claims 1 to 3, characterized in that, The heat pump system also includes: Water supply temperature detection unit (8) is used to detect the water temperature at the water supply port of the hot water channel; The defrosting temperature detection unit (9) is used to detect the temperature inside the defrosting chamber (521); And / or, the heat pump system further includes: The heating return water temperature detection unit is located upstream of the first preset position. The return water inlet of the hot water channel is connected to the heating return water pipe. The heating return water pipe is connected to the defrost outlet of the defrost chamber (521) at a first preset position. Along the water flow direction in the heating return water pipe, the heating return water temperature detection unit is located upstream of the first preset position.

5. The heat pump system according to any one of claims 1 to 3, characterized in that, The defrosting structure (52) has a defrosting drain port that communicates with the defrosting chamber (521), and the defrosting drain port is equipped with a drain switch valve (10); And / or, the water receiving tray (51) is provided with a water receiving and drain outlet (53) for discharging the water in the water receiving tray (51) into the external environment.

6. A heat pump system control method, characterized in that, For the heat pump system according to any one of claims 1 to 5, the heat pump system control method includes: Upon receiving the defrosting start command, the defrosting valve (6) is controlled to open the defrosting circulation loop.

7. The heat pump system control method according to claim 6, characterized in that, When the defrosting function is turned off, the defrosting valve (6) is controlled to disconnect the defrosting circulation loop. The defrosting function is turned off under the following conditions: receiving a user input command to end the process; or, the temperature difference between the water supply outlet temperature of the hot water channel and the temperature inside the defrosting chamber (521) is less than the preset end temperature difference; or, the duration of defrosting exceeds the preset defrosting duration.

8. The heat pump system control method according to claim 6, characterized in that, When the temperature inside the defrosting chamber (521) is lower than the preset drainage temperature, the drain switch valve (10) is controlled to drain the water inside the defrosting chamber (521); And when the drainage duration reaches the preset drainage duration, control the drainage switch valve (10) to stop drainage.

9. The heat pump system control method according to claim 8, characterized in that, The heat pump system control method further includes: Obtain the heating return water temperature at a second preset position in the heating return water pipe. Along the water flow direction in the heating return water pipe, the second preset position is located upstream of the first preset position of the defrost outlet of the heating return water pipe that connects to the defrost chamber (521). When the heating return water temperature is lower than the preset minimum return water temperature, determine whether the operating power of the compressor (1) has reached the preset maximum power; If the operating power of the compressor (1) does not reach the preset maximum power, the power of the compressor (1) is increased; if the operating power of the compressor (1) reaches the preset maximum power, the opening degree of the defrosting circulation loop is reduced. The conduction degree of the defrosting circulation loop includes the connection degree of the hot water supply port of the hot water channel and the defrosting inlet of the defrosting chamber (521), and / or the connection degree of the return port of the hot water channel and the defrosting outlet of the defrosting chamber (521).

10. The heat pump system control method according to claim 9, characterized in that, Before reducing the conduction opening of the defrosting circulation loop, the method further includes: determining whether the conduction opening of the defrosting circulation loop is greater than a preset minimum opening. If the conduction opening of the defrosting circulation loop is greater than the preset minimum opening, then the conduction opening of the defrosting circulation loop shall be reduced. If the opening degree of the defrosting circulation loop is not greater than the preset minimum opening degree, then the opening degree of the defrosting circulation loop is controlled to be maintained at the preset minimum opening degree.

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