A control method, device and heat pump unit for a heat pump unit

Abstract

The present invention discloses a control method, device and heat pump unit for a heat pump unit. Among them, the method includes: after the compressor starts, determining whether the condensation temperature and exhaust pressure of the unit meet the preset regulation conditions; if so, reducing the operating frequency and frequency increase speed of the compressor until the preset regulation conditions are no longer met; if not, further detecting whether the operating parameters of the compressor are abnormal; if so, determining whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor; if it is an occasional abnormality, executing the corresponding regulation strategy; if it is a frequent abnormality, further determining the abnormal level and executing the corresponding regulation strategy according to the abnormal level. Through the present invention, the control strategy of the heat pump unit is refined, and when the unit encounters an abnormality, its operating state can be adjusted according to the situation, improving its adaptability on the premise of ensuring the safety and reliability of the unit. Avoiding frequent shutdowns of the unit and enhancing the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of units, and in particular, to a control method, device and heat pump unit for a heat pump unit. Background Art

[0002] The application field of heat pump products has been further expanded, and the role played by heat pump products in production and life has become increasingly important. For a heat pump unit, the existing abnormal situation handling strategy of the heat pump unit is relatively rough, and it will stop when encountering a small abnormality, and it cannot adapt to the changing engineering environment. The frequent shutdown of the unit will affect the normal use of users, and the user experience is poor.

[0003] Aiming at the problem that the existing abnormal response control strategy of the heat pump unit is rough, resulting in frequent shutdowns of the unit, no effective solution has been proposed yet. Summary of the Invention

[0004] An embodiment of the present invention provides a control method, device and heat pump unit for a heat pump unit to solve the problem that the existing abnormal response control strategy of the heat pump unit is rough, resulting in frequent shutdowns of the unit.

[0005] To solve the above technical problem, the present invention provides a control method for a heat pump unit, wherein the method includes: after the compressor is started, determining whether the condensation temperature and exhaust pressure of the unit meet the preset regulation conditions; if they meet the preset regulation conditions, reducing the operating frequency and frequency increase speed of the compressor until they no longer meet the preset regulation conditions; if they do not meet the preset regulation conditions, further detecting whether the operating parameters of the compressor are abnormal; if so, determining whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor; if it is an occasional abnormality, executing the corresponding regulation strategy; if it is a frequent abnormality, further determining whether the abnormal level is a first-level abnormality or a second-level abnormality, and executing the corresponding regulation strategy according to the abnormal level.

[0006] Further, before the compressor is started, the method further includes: after sending an opening command to the circulation pump, detecting whether the water flow switch is closed; if so, controlling the compressor to start at a preset frequency increase speed; if not, confirming that the water flow switch is faulty, and then controlling the compressor to start at a frequency increase speed lower than the preset frequency increase speed.

[0007] Further, before sending an opening command to the circulation pump, the method further includes: after the unit receives the start command, detecting whether the water flow switch is closed; if so, prompting that the water flow switch is abnormal, and / or, prompting that the circulation pump is not controlled by the unit; then triggering to send an opening command to the circulation pump; if not, triggering to send an opening command to the circulation pump.

[0008] Further, the preset regulation conditions include: condensation temperature > outlet water temperature + k > preset temperature; and, discharge pressure < preset protection pressure; where k is a constant.

[0009] Further, the operating parameters of the compressor at least include one of the following: outlet water temperature, discharge temperature, discharge pressure, current; detecting whether the operating parameters of the compressor are abnormal includes: determining whether at least one of the following conditions is satisfied: outlet water temperature ≥ preset overheat temperature, discharge temperature ≥ preset protection temperature, discharge pressure ≥ preset protection pressure, current ≥ preset protection current; if so, it is determined that the operating parameters of the compressor are abnormal.

[0010] Further, after further detecting whether the operating parameters of the compressor are abnormal, the method further includes: if there is no abnormality, accumulating the fault - free operation duration of the compressor; after the fault - free operation duration exceeds the preset duration, clearing the accumulated fault times, and restoring the preset upper limit frequency of the compressor to the preset initial value.

[0011] Further, judging whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor includes: detecting the current operating frequency of the compressor, and comparing the operating frequency with the preset minimum operating frequency; if the current operating frequency of the compressor > preset minimum operating frequency, it is determined that the abnormal situation is an occasional abnormality; if the current operating frequency of the compressor ≤ preset minimum operating frequency, it is determined that the abnormal situation is a frequent abnormality.

[0012] Further, after further detecting whether the operating parameters of the compressor are abnormal, the method further includes: if it is determined that the operating parameters of the compressor are abnormal, controlling the compressor to stop.

[0013] Further, if it is an occasional abnormality, implementing the corresponding regulation strategy includes: reducing the compressor frequency - increasing speed and the preset upper limit frequency; controlling the compressor to start according to the reduced frequency - increasing speed and the preset upper limit frequency.

[0014] Further, after controlling the compressor to start according to the reduced frequency - increasing speed and the preset upper limit frequency, the method further includes: accumulating the fault - free operation duration of the compressor; after the fault - free operation duration exceeds the preset duration, clearing the accumulated fault times, and restoring the preset upper limit frequency of the compressor to the preset initial value.

[0015] Further, if it is a frequent abnormality, further judging whether the abnormal level is a first - level abnormality or a second - level abnormality includes: judging whether the accumulated fault times exceed the preset times; where the fault times are accumulated since the unit starts to operate; if so, it is determined as a first - level abnormality; if not, it is determined as a second - level abnormality.

[0016] Further, corresponding regulation strategies are executed according to the anomaly level, including: if it is a first-level anomaly, the unit locks the fault state; thereafter, it is judged whether the preset anti-freezing condition is met according to the temperature parameter, if it is met, the unit starts up and enters the anti-freezing operation; if it is not met, the fault state is continuously locked; the temperature parameter is continuously monitored, and it is judged whether the temperature parameter meets the preset anti-freezing exit condition; if it is met or the unit fails and shuts down, the anti-freezing operation is exited.

[0017] Further, after judging whether the temperature parameter meets the preset anti-freezing exit condition, the method further includes: if the temperature parameter does not meet the preset anti-freezing exit condition, the fault-free operation duration of the compressor is accumulated; after the fault-free operation duration exceeds the preset duration, the accumulated number of faults is cleared, and the compressor is controlled to restart normally.

[0018] Further, corresponding regulation strategies are executed according to the anomaly level, including: if it is a second-level anomaly, the end return water temperature of the unit is monitored; after the end return water temperature drops by a preset degree, the frequency increase speed and the preset upper limit frequency of the compressor are reduced; the compressor is controlled to start according to the reduced frequency increase speed and the preset upper limit frequency.

[0019] The present invention provides a heat pump unit control device, wherein the device includes: a judgment module, after the compressor starts, judging whether the condensation temperature and the exhaust pressure of the unit meet the preset regulation conditions; a first regulation module, used for when the judgment result of the judgment module meets the preset regulation conditions, reducing the operating frequency and the frequency increase speed of the compressor until it no longer meets the preset regulation conditions; a second regulation module, used for when the judgment result of the judgment module does not meet the preset regulation conditions, further detecting whether the operating parameters of the compressor are abnormal; if so, judging whether the abnormal situation is an occasional anomaly or a frequent anomaly according to the operating frequency of the compressor; if it is an occasional anomaly, execute the corresponding regulation strategy; if it is a frequent anomaly, further judge whether the anomaly level is a first-level anomaly or a second-level anomaly, and execute the corresponding regulation strategy according to the anomaly level.

[0020] The present invention provides a heat pump unit, wherein the heat pump unit at least includes the above-mentioned heat pump unit control device.

[0021] The present invention provides a computer-readable storage medium, on which a computer program is stored, wherein the program, when executed by a processor, implements the method as described above.

[0022] Applying the technical solution of the present invention, the abnormal response control strategy of the heat pump unit is refined. When the unit encounters an anomaly, its operating state can be adjusted according to the situation. On the premise of ensuring the safety and reliability of the unit, its adaptability is improved, frequent shutdowns of the unit are avoided, and the user experience is enhanced. Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of a heat pump unit according to an embodiment of the present invention;

[0024] Figure 2 is a flowchart of a control method for a heat pump unit according to an embodiment of the present invention;

[0025] Figure 3 is a flowchart of a refined control strategy for a heat pump unit according to an embodiment of the present invention;

[0026] Figure 4 is a structural block diagram of a control device for a heat pump unit according to an embodiment of the present invention. Detailed implementation manners

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0028] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "the" and "said" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0029] It should be understood that the term " / and" used herein is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0030] Depending on the context, the words "if", "when" as used herein may be interpreted as "when" or "when... " or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (stated condition or event)" may be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0031] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the commodity or device comprising said element.

[0032] The optional embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] Embodiment 1

[0034] Figure 1 is a schematic structural diagram of a heat pump unit according to an embodiment of the present invention, as Figure 1 shown. The circulating water pump in the heat pump unit is arranged between the water-side heat exchanger and the water tank. The circulating water pump is used to provide power for the water, pumping the water from the water tank into the water-side heat exchanger for heating. The water flow switch is arranged between the water-side heat exchanger and the water tank. On the water inlet side of the water tank, the water flow switch is used to detect the water pipe flow rate. When the water flow rate is lower than the water flow protection value, the water flow switch disconnects; when the water flow rate is higher than the water flow protection value, the water flow switch closes. The heat pump unit of this embodiment is also provided with an exhaust pressure sensor, as Figure 1 shown. The exhaust pressure sensor is arranged on the pipeline between the compressor and the four-way valve, and is used to detect the exhaust pressure. The exhaust pressure can be converted to obtain the condensation temperature (for example, it can be obtained by looking up the refrigerant physical property parameter table). The heat pump unit also includes an outlet water temperature sensor, arranged on the pipeline between the water-side heat exchanger and the water tank, for detecting the outlet water temperature; an exhaust temperature sensor, arranged on the pipeline between the compressor and the four-way valve, for detecting the exhaust temperature; and also includes a suction temperature sensor, arranged on the pipeline between the compressor and the gas-liquid separator, for detecting the suction temperature; an inlet water temperature sensor, arranged on the pipeline between the water-side heat exchanger and the water tank, for detecting the inlet water temperature. When implementing the abnormal response control strategy, the operating parameters that need to be referred to in the heat pump unit of this embodiment at least include one of the following: the above-mentioned outlet water temperature, the above-mentioned exhaust temperature, the above-mentioned exhaust pressure, and the current. Herein, the current refers to the input current of the compressor, and its detection position is on the compressor variable frequency drive board. The current detection device can be arranged between the power supply and the compressor.

[0035] Based on the structure of the heat pump unit introduced above, this embodiment proposes a control method for the heat pump unit, Figure 2 which is a flowchart of the control method for the heat pump unit according to an embodiment of the present invention, as Figure 2 shown. The method includes the following steps:

[0036] Step S201, after the compressor starts, determine whether the condensing temperature and the exhaust pressure of the unit meet the preset control conditions; specifically, the above-mentioned preset control conditions include: condensing temperature > outlet water temperature + k > preset temperature; and, exhaust pressure < preset protection pressure; where k is a constant; of course, the above-mentioned preset control conditions can also be set according to the actual working conditions, such as setting the specific value of k, setting the magnitude of the preset protection pressure, and so on.

[0037] Step S202, if the preset control conditions are met, reduce the operating frequency and the frequency increase speed of the compressor until the preset control conditions are no longer met.

[0038] Step S203, if the preset control conditions are not met, further detect whether the operating parameters of the compressor are abnormal; if so, execute Step S204, if not, execute Step S207.

[0039] Step S204, if the operating parameters of the compressor are abnormal, determine whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor.

[0040] Step S205, if it is an occasional abnormality, execute the corresponding control strategy.

[0041] Step S206, if it is a frequent abnormality, further determine whether the abnormality level is a first-level abnormality or a second-level abnormality, and execute the corresponding control strategy according to the abnormality level.

[0042] Step S207, if the operating parameters of the compressor are not abnormal, accumulate the fault-free operation duration of the compressor; after the fault-free operation duration exceeds the preset duration, clear the accumulated number of faults, and restore the preset upper limit frequency of the compressor to the preset initial value.

[0043] This embodiment makes the control strategy of the heat pump unit refined. When the unit encounters an abnormality, it can adjust the operating state according to the situation, improve its adaptability on the premise of ensuring the safety and reliability of the unit. Avoid frequent shutdowns of the unit and enhance the user experience.

[0044] For the control strategy of the heat pump unit, a detailed introduction is given below. The above operating parameters include at least one of the following: outlet water temperature, exhaust temperature, exhaust pressure, and current. The detection locations for these operating parameters have been introduced previously. In the above step S203, if the condensation temperature and exhaust pressure of the unit meet the preset regulation conditions, it indicates that the compressor frequency increase is too fast and the frequency is too high at this time, and regulation is required. Therefore, it is necessary to reduce the operating frequency and frequency increase speed of the compressor to control the condensation temperature within a reasonable range. That is, when the above situation of too fast and too high compressor frequency increase occurs, a regulation operation is promptly performed on it. At this time, if there are flow fluctuations and temperature fluctuations in the water system, the above regulation operation can respond promptly and quickly to avoid abnormal shutdown of the unit. The above regulation operation ends when the condensation temperature and exhaust pressure of the unit no longer meet the preset regulation conditions.

[0045] If the condensation temperature and exhaust pressure of the unit do not meet the preset regulation conditions, and at this time, there is no need to regulate the compressor, then further monitor whether there are abnormalities in the water circuit, such as pump failure, water shortage, water pipe bursting / blockage, etc., which may cause the unit to malfunction and be protected. Abnormal situations need to be monitored and handled according to different situations.

[0046] The abnormal monitoring scheme is as follows: Detect whether the operating parameters of the compressor are abnormal. Specifically: Determine whether at least one of the following conditions is met: outlet water temperature ≥ preset overheat temperature, exhaust temperature ≥ preset protection temperature, exhaust pressure ≥ preset protection pressure, current ≥ preset protection current; if so, it is determined that the operating parameters of the compressor are abnormal. It should be noted that after determining that the operating parameters of the compressor are abnormal in the above step S203, it is necessary to control the compressor to stop running to avoid incorrect operation of the unit under abnormal conditions.

[0047] If it is determined that the operating parameters of the compressor are abnormal, then further distinguish the severity of the abnormal situation, and corresponding regulation operations can be performed according to its severity. Preferably, determine whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor. Specifically: Detect the current operating frequency of the compressor and compare the operating frequency with the preset minimum operating frequency. Through this technical means, the severity of the abnormal situation is distinguished.

[0048] If the current operating frequency of the compressor > the preset minimum operating frequency, it indicates that the abnormality in the water circuit is sporadic at this time, so the abnormal situation is determined to be a sporadic abnormality. If it is a long-term frequent abnormality, there will be an abnormality during the startup phase, and the unit will be protected during the frequency increase process, and the frequency of the unit starts from 0Hz. The control strategies corresponding to sporadic abnormalities include: reducing the compressor frequency increase speed and the preset upper limit frequency; controlling the compressor startup according to the reduced frequency increase speed and preset upper limit frequency, and trying to start the compressor slowly. It should be noted that the preset upper limit frequency determined after the reduction = (the compressor frequency before the sporadic abnormality condition strategy - the preset value, the preset minimum operating frequency), that is, the minimum value between the above two frequency values is taken as the preset upper limit frequency after the reduction.

[0049] After that, accumulate the fault-free operation duration of the compressor; after the fault-free operation duration exceeds the preset duration, clear the accumulated number of faults, and restore the preset upper limit frequency of the compressor to the preset initial value. For example, if the accumulated fault-free operation duration of the compressor after startup ≥ 180 minutes, it is considered that the water circuit abnormality has been restored, clear the number of faults, and at the same time restore the compressor upper limit frequency.

[0050] If the current operating frequency of the compressor ≤ the preset minimum operating frequency, then the abnormal situation is determined to be a frequent abnormality. In this case, the compressor cannot continue to operate, and then further determine whether the abnormal level is a first-level abnormality or a second-level abnormality. Specifically: judge whether the accumulated number of faults exceeds the preset number; among them, the number of faults is accumulated starting from when the unit starts up and runs; if so, it is determined to be a first-level abnormality; if not, it is determined to be a second-level abnormality.

[0051] If it is a first-level abnormality, it means that there is a serious problem with the unit at this time, and it cannot be started again until the rectification control is completed, and the unit locks the fault state; after that, judge whether it meets the preset anti-freezing condition according to the temperature parameter. If it meets, the unit starts up and enters the anti-freezing operation; if it does not meet, continue to lock the fault state; continue to monitor the temperature parameter and judge whether the temperature parameter meets the preset anti-freezing exit condition; if it meets or the unit fails and stops, exit the anti-freezing operation. If the temperature parameter does not meet the preset anti-freezing exit condition, accumulate the fault-free operation duration of the compressor; after the fault-free operation duration exceeds the preset duration, it means that the unit abnormality has been repaired, clear the accumulated number of faults, and control the compressor to start normally again.

[0052] The above preset anti-freezing condition can be: the ambient temperature < 2°C, and min(water inlet temperature, water outlet temperature) < 2°C; the above preset anti-freezing exit condition can be: min(water inlet temperature, water outlet temperature) > 10°C. Of course, the above is only an example, and the specific conditions can be determined according to the actual working conditions and weather conditions.

[0053] If it is a secondary anomaly, monitor the return water temperature at the end of the unit (a temperature sensor can be set at the water inlet of the unit). After the return water temperature at the end drops by a preset degree (e.g., 5 degrees), the operating load of the unit will decrease accordingly. If the fault is restored during this period, the unit can resume operation accordingly. This process provides a preset number of attempt opportunities to try to start the compressor: reduce the compressor frequency increase speed and the preset upper limit frequency; control the compressor to start according to the reduced frequency increase speed and the preset upper limit frequency.

[0054] Before adjusting and controlling the unit anomaly, it is necessary to first confirm whether the water flow switch is abnormal, that is, before starting the compressor, after sending an opening command to the circulating water pump, detect whether the water flow switch is closed; if so, control the compressor to start at the preset frequency increase speed; if not, confirm the water flow switch failure, and then control the compressor to start at a frequency increase speed lower than the preset frequency increase speed.

[0055] It should be noted that after the unit is powered on, it is necessary to first judge whether the water flow switch is abnormal and whether the circulating water pump is controlled by this unit, that is, after the unit receives the power-on command, detect whether the water flow switch is closed; if so, prompt that the water flow switch is abnormal and / or prompt that the circulating water pump is not controlled by the unit, and then trigger to send an opening command to the circulating water pump; if not, trigger to send an opening command to the circulating water pump. According to the conventional control sequence of the heat pump unit, the unit generally sends a water pump opening command after receiving the power-on command. At this time, the closed water flow switch proves that the water pump has been started. If the unit has not sent an opening command for the water pump at this time, it can be judged whether the water flow switch is abnormal accordingly. For the circulating water pump not being controlled by the unit, it means that the water pump is controlled by other engineering equipment, and the control command of the unit cannot be transmitted there, which will cause water shortage protection, defrosting freezing protection, etc. during the operation of the unit.

[0056] Embodiment 2

[0057] Figure 3 It is a flowchart of the refined control strategy of the heat pump unit according to the embodiment of the present invention.

[0058] As Figure 3 shown, the process includes the following steps:

[0059] Step S301, the unit receives a power-on command.

[0060] Step S302, detect whether the water flow switch is closed; if so, it means that the water flow switch has been closed before the water pump starts, prompt that the water flow switch is abnormal or the water pump is not controlled by the unit, and then turn on the water circulation pump; if not, turn on the water circulation pump. That is, the unit confirms whether the water pump is controlled by the unit and whether the water flow switch is abnormal by judging the state of the water flow switch before and after the water pump opening command is sent.

[0061] Step S303: After turning on the water circulation pump, detect whether the water flow switch is closed at this time. If it is, execute Step S306; if not, execute Step S304.

[0062] Step S304: Report a water flow switch fault.

[0063] Step S305: The compressor starts at 1 / 4 of the normal frequency increase speed (preset frequency increase speed), and a prompt is given that the water flow switch is abnormal or the water pump has not started.

[0064] Step S306: The compressor starts at the normal frequency increase speed.

[0065] Step S307: Record the frequency increase speed at this time and denote it as v.

[0066] If the water flow switch is normal, start and run at the normal frequency increase speed; otherwise, it is necessary to test and run by increasing the frequency at a low speed to confirm the water circuit condition, to avoid water shortage in the water circuit and the unit increasing the frequency too fast without "braking", resulting in device damage.

[0067] Step S308: After the compressor starts, detect the condensation temperature condition of the unit and judge whether it satisfies: condensation temperature > outlet water temperature + 10°C > 50°C, and the exhaust pressure < protection pressure; if it is, execute Step S309; if not, execute Step S310.

[0068] Step S309: If it is, it is considered that the frequency increase is too fast and the frequency is too high at this time. It is necessary to reduce the operating frequency and the frequency increase speed. For example, the compressor frequency is reduced to 2 hz and the frequency increase speed is reduced to 0.9V. Control the condensation temperature within a reasonable range. At this time, if there are fluctuations in the water system flow and temperature, this control can respond in a timely manner and quickly, avoiding abnormal shutdown of the unit.

[0069] Step S310: Judge whether the following conditions are met: outlet water temperature ≥ superheat temperature, or, exhaust temperature ≥ protection temperature, or, exhaust pressure ≥ protection pressure, or, current ≥ protection current. If it is, execute Step S312; if not, execute Step S311.

[0070] That is, judge whether the water circuit has an abnormality, such as water pump failure, water shortage, water pipe bursting / blockage, etc., resulting in unit fault protection, and handle it according to different situations.

[0071] Step S311: If the above conditions are not met, judge whether the continuous fault-free operation duration is greater than or equal to 180 minutes. If it is, it means that the compressor has returned to normal, clear the fault count, and restore the upper limit frequency of the compressor.

[0072] Step S312, if so, further determine whether the following conditions are met: compressor frequency ≤ minimum operating frequency, record this frequency as F, and record the inlet water temperature as T.

[0073] If so, execute Step S314; if not, execute Step S313.

[0074] Step S313, if the compressor operating frequency before fault protection > minimum operating frequency, it is considered that the abnormality of the water circuit is sporadic at this time. By means of controlling the compressor frequency increase speed and upper limit frequency reduction, try to start the compressor slowly, and control the compressor upper limit frequency = max(F - 2, minimum operating frequency). If the compressor runs without fault for a duration ≥ 180 minutes after startup, it is considered that the water circuit abnormality has been restored, clear the fault count, and at the same time restore the compressor upper limit frequency.

[0075] Step S314, if the compressor operating frequency before fault protection ≤ minimum operating frequency, it is considered that the compressor cannot continue to operate under this condition, then stop the machine and record it as the fault count.

[0076] Step S315, determine whether the accumulated fault count ≥ 5. If so, execute Step S317; if not, execute Step S316.

[0077] Step S316, if the accumulated fault count < 5, wait until the inlet water temperature drops by 5°C (inlet water temperature < T - 5), then try to start the compressor again and execute Step S313.

[0078] Step S317, if the accumulated fault count ≥ 5, it is considered that the unit has a serious problem and cannot be started again until rectification is completed. The unit will display a fault, lock the fault status, and when the anti-freezing condition is met: ambient temperature < 2°C, and min(inlet, outlet) < 2°C, the compressor starts, and anti-freezing operation is carried out at an increase frequency speed of v and an upper limit frequency of F.

[0079] Detect whether the anti-freezing exit condition is met: min(inlet, outlet) > 10°C, or whether a fault shutdown occurs. If so, exit the anti-freezing. If the cumulative fault-free operation time during anti-freezing ≥ 180 minutes, it is judged that the unit abnormality has been repaired. At this time, clear the fault and the fault count, and the compressor starts normal heating again.

[0080] This embodiment makes a refined treatment of the abnormal response control strategy of the heat pump unit. When the unit encounters an abnormality, it can adjust the operating state according to the situation, improve its adaptability on the premise of ensuring the safety and reliability of the unit, avoid frequent shutdowns of the unit, and enhance the user experience.

[0081] Embodiment 3

[0082] Corresponding to Figure 2The flowchart of the control method for the heat pump unit is introduced. This embodiment provides a control device for the heat pump unit, as Figure 4 shown in the structural block diagram of the control device for the heat pump unit. The device includes:

[0083] A judgment module 10, which, after the compressor starts, judges whether the condensation temperature and exhaust pressure of the unit meet the preset regulation conditions;

[0084] A first regulation module 20, connected to the judgment module 10, is used to reduce the operating frequency and frequency increase speed of the compressor until the preset regulation conditions are no longer met when the judgment result of the judgment module 10 meets the preset regulation conditions;

[0085] A second regulation module 30, connected to the first regulation module 20, is used to further detect whether the operating parameters of the compressor are abnormal when the judgment result of the judgment module 10 does not meet the preset regulation conditions; if so, judge whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor; if it is an occasional abnormality, execute the corresponding regulation strategy; if it is a frequent abnormality, further judge whether the abnormal level is a first-level abnormality or a second-level abnormality, and execute the corresponding regulation strategy according to the abnormal level.

[0086] This embodiment also provides a heat pump unit, which at least includes the above-mentioned control device for the heat pump unit.

[0087] Embodiment 4

[0088] This embodiment of the present invention provides a software, which is used to execute the technical solutions described in the above embodiments and preferred embodiments.

[0089] This embodiment of the present invention provides a non-volatile computer storage medium, and the computer storage medium stores computer-executable instructions, and the computer-executable instructions can execute the control method for the heat pump unit in any of the above method embodiments.

[0090] The above-mentioned software is stored in the above-mentioned storage medium, and the storage medium includes but is not limited to: optical discs, floppy discs, hard disks, erasable memories, etc.

[0091] The above products can execute the methods provided by the embodiments of the present invention, and have the corresponding functional modules and beneficial effects for executing the methods. For the technical details not described in detail in this embodiment, reference can be made to the methods provided by the embodiments of the present invention.

[0092] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0093] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a heat pump unit, characterized in that, The method includes: After the compressor starts, determine whether the condensation temperature and exhaust pressure of the unit meet the preset regulation conditions; If they meet the preset regulation conditions, reduce the operating frequency and frequency increase speed of the compressor until they no longer meet the preset regulation conditions; if they do not meet the preset regulation conditions, further detect whether the operating parameters of the compressor are abnormal; If so, determine whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor; if it is an occasional abnormality, execute the corresponding regulation strategy; if it is a frequent abnormality, further determine whether the abnormal level is a first-level abnormality or a second-level abnormality, and execute the corresponding regulation strategy according to the abnormal level.

2. The method according to claim 1, wherein Before the compressor starts, the method further includes: After sending an opening command to the circulating water pump, detect whether the water flow switch is closed; If so, control the compressor to start at the preset frequency increase speed; If not, confirm that the water flow switch is faulty, and then control the compressor to start at a frequency increase speed lower than the preset frequency increase speed.

3. The method according to claim 2, characterized in that, Before sending an opening command to the circulating water pump, the method further includes: After the unit receives the startup command, detect whether the water flow switch is closed; If so, prompt that the water flow switch is abnormal, and / or, prompt that the circulating water pump is not controlled by the unit; then trigger sending an opening command to the circulating water pump; If not, trigger sending an opening command to the circulating water pump.

4. The method according to claim 1, wherein The preset regulation conditions include: Condensation temperature > outlet water temperature + k > preset temperature; and, exhaust pressure < preset protection pressure; where k is a constant.

5. The method according to claim 1, characterized in that The operating parameters of the compressor at least include one of the following: outlet water temperature, exhaust temperature, exhaust pressure, current; Detecting whether the operating parameters of the compressor are abnormal includes: Judging whether at least one of the following conditions is satisfied: outlet water temperature ≥ preset overheat temperature, exhaust temperature ≥ preset protection temperature, exhaust pressure ≥ preset protection pressure, current ≥ preset protection current; If so, determine that the operating parameters of the compressor are abnormal.

6. The method according to claim 1, characterized in that, After further detecting whether the operating parameters of the compressor are abnormal, the method further includes: If there is no abnormality, accumulate the fault-free operation duration of the compressor; After the fault-free operation duration exceeds the preset duration, clear the accumulated number of faults, and restore the preset upper limit frequency of the compressor to the preset initial value.

7. The method according to claim 1, wherein Determining whether the abnormal situation is an occasional abnormality or a frequent abnormality according to the operating frequency of the compressor includes: Detect the current operating frequency of the compressor, and compare the operating frequency with the preset minimum operating frequency; If the current operating frequency of the compressor > preset minimum operating frequency, determine that the abnormal situation is an occasional abnormality; If the current operating frequency of the compressor ≤ preset minimum operating frequency, determine that the abnormal situation is a frequent abnormality.

8. The method according to claim 1, wherein After further detecting whether the operating parameters of the compressor are abnormal, the method further includes: If it is determined that the operating parameters of the compressor are abnormal, control the compressor to stop.

9. The method according to claim 8, wherein If it is an occasional abnormality, execute the corresponding regulation strategy, including: Reduce the compressor frequency increase speed and preset upper limit frequency; Control the compressor to start according to the reduced frequency increase speed and preset upper limit frequency.

10. The method according to claim 9, wherein After controlling the compressor to start according to the reduced frequency increase speed and preset upper limit frequency, the method further includes: Accumulate the fault-free operation duration of the compressor; After the fault-free operation duration exceeds the preset duration, clear the accumulated number of faults, and restore the preset upper limit frequency of the compressor to the preset initial value.

11. The method according to claim 1, wherein If it is a frequently occurring anomaly, further determine whether the anomaly level is a first-level anomaly or a second-level anomaly, including: Judge whether the accumulated number of faults exceeds the preset number; among them, the number of faults is accumulated since the unit starts running; If so, determine it as a first-level anomaly; If not, determine it as a second-level anomaly.

12. The method according to claim 8, wherein Execute corresponding regulation strategies according to the anomaly level, including: If it is a first-level anomaly, the unit locks the fault state; After that, judge whether it meets the preset anti-freezing condition according to the temperature parameter. If it meets, the unit starts up and enters the anti-freezing operation; if it does not meet, continue to lock the fault state; Continue to monitor the temperature parameter and judge whether the temperature parameter meets the preset anti-freezing exit condition; if it meets or the unit fails and shuts down, exit the anti-freezing operation.

13. The method according to claim 12, characterized in that, After judging whether the temperature parameter meets the preset anti-freezing exit condition, the method further includes: If the temperature parameter does not meet the preset anti-freezing exit condition, accumulate the fault-free operation duration of the compressor; After the fault-free operation duration exceeds the preset duration, clear the accumulated number of faults, and control the compressor to restart normally.

14. The method according to claim 8, characterized in that Execute corresponding regulation strategies according to the anomaly level, including: If it is a second-level anomaly, monitor the return water temperature at the end of the unit; After the return water temperature at the end drops by a preset degree, reduce the frequency increase speed and the preset upper limit frequency of the compressor; control the compressor to start according to the reduced frequency increase speed and the preset upper limit frequency.

15. A control device for a heat pump unit, characterized in that, The device includes: A judgment module, after the compressor starts, judge whether the condensation temperature and the exhaust pressure of the unit meet the preset regulation conditions; A first regulation module, used to reduce the operating frequency and the frequency increase speed of the compressor until it no longer meets the preset regulation conditions when the judgment result of the judgment module meets the preset regulation conditions; A second regulation module, used to further detect whether the operating parameters of the compressor are abnormal when the judgment result of the judgment module does not meet the preset regulation conditions; if so, judge whether the abnormal situation is an occasional anomaly or a frequently occurring anomaly according to the operating frequency of the compressor; if it is an occasional anomaly, execute the corresponding regulation strategy; if it is a frequently occurring anomaly, further judge whether the anomaly level is a first-level anomaly or a second-level anomaly, and execute the corresponding regulation strategy according to the anomaly level.

16. A heat pump unit, characterized in that, The heat pump unit at least includes the heat pump unit control device described in claim 15.

17. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, it implements the method described in any one of claims 1 to 14.

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