Multi-stage preheating based ultra-high temperature heat pump starting cooperative control system and method

Abstract

The application provides a multi-stage preheating-based ultra-high temperature heat pump starting cooperative control system and method, which comprises the following steps: collecting temperature signals of three points, i.e., the bottom of a compressor, the bottom of a gas-liquid separator and the water inlet of an evaporator, and comparing the temperature signals with preset starting threshold values; if any temperature fails to meet the standard, controlling the corresponding heating device to independently heat until the temperatures of the three points all reach the preset threshold values; judging whether the lubricating oil is activated from a high viscosity state to a flowing state based on the temperature of the bottom of the gas-liquid separator and the temperature rising rate thereof; under the activated state of the lubricating oil, calculating the pre-position opening degree of an electronic expansion valve and controlling the electronic expansion valve to be opened to establish a micro pressure difference; based on the micro pressure difference and the oil return state, constructing a cooperative readiness index to judge whether the system meets the starting condition; if the starting condition is met, selecting a starting mode of the compressor according to the size of the cooperative readiness index and performing a starting operation; after the completion, switching to a normal running mode of the system, removing the preheating device and restoring a standard control program.

Description

Technical Field

[0001] This invention belongs to the field of heat pumps, and particularly relates to a collaborative control system and method for starting up an ultra-high temperature heat pump based on multi-stage preheating. Background Technology

[0002] With the widespread application of heat pump technology in industrial and civil fields such as high-temperature drying and heating, the choice of refrigerant directly affects the safety and reliability of the system. Existing heat pump systems mostly use medium- and low-temperature refrigerants such as R410A, R134a, R407C, R32, and R290. These refrigerants generally have boiling points below room temperature. When the system is stopped or in standby mode, the low-pressure side is mainly in a gaseous or easily vaporized liquid state. When the compressor starts, it can achieve vaporization by relying on the negative pressure generated by the compressor itself, thus ensuring smooth start-up, low risk of liquid slugging, and maintenance of oil film protection. However, R1233zd, as a low-GWP ultra-high-temperature refrigerant, has a boiling point of 18.26℃ and is in a liquid state at room temperature, which is significantly different from medium- and low-temperature refrigerants. When the system is stopped, liquid refrigerant often remains in the bottom cavity of the compressor and the bottom of the gas-liquid separator, and the accompanying high-temperature lubricating oil has high viscosity and poor fluidity at room temperature. If the system is started directly under these conditions, the liquid refrigerant can easily wash away the oil film in the compression chamber, causing liquid slugging and dry friction, severely affecting the compressor's lifespan. Meanwhile, the liquid on the low-pressure side is not completely vaporized, making it easy for the compressor to trigger a false alarm of low-pressure protection when drawing negative pressure, thus damaging the low-pressure switch. Because the evaporator and condenser sides lack preheating during startup, the system's high and low pressure differential forms slowly, resulting in large fluctuations in the initial operating phase. The compressor operates in an unstable condition, further accelerating wear. More significantly, the high-viscosity lubricating oil remaining at the bottom of the gas-liquid separator at room temperature is difficult to return in time, leading to oil shortage operation of the compressor during the initial startup phase. Existing improvement measures, such as simply adding a crankshaft heating belt or setting a fixed preheating time, are mostly solutions for low-boiling-point refrigerants and cannot truly solve the problems of liquid slugging, false alarms, slow pressure differential, and oil shortage encountered by the R1233zd system during startup. Summary of the Invention

[0003] The purpose of this invention is to design a multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control system and method, which can cover safety control throughout the entire process from system preheating to final operation switching, and provides solutions to problems such as liquid slugging, false alarms, slow differential pressure and oil shortage that cannot be overcome by traditional strategies.

[0004] To achieve the above objectives, a first aspect of the present invention provides a collaborative control method for the start-up of an ultra-high temperature heat pump based on multi-stage preheating, the method comprising:

[0005] The system collects raw temperature signals and compares them with preset start-up thresholds. If any temperature fails to meet the threshold, the corresponding heating device is controlled to heat independently until all three temperatures reach the preset threshold. Based on the temperature at the bottom of the gas-liquid separator and the rate of temperature rise, it determines whether the lubricating oil has been activated from a high-viscosity state to a fluid state.

[0006] When the lubricating oil is activated into a flow state, the one-time pre-position opening of the electronic expansion valve is calculated, and its opening is controlled to establish a micro pressure difference. The magnitude of the micro pressure difference is estimated, and the oil return is determined based on the micro pressure difference.

[0007] Based on the aforementioned differential pressure and oil return status, a collaborative readiness index is constructed, and the startup conditions are determined based on the collaborative readiness index.

[0008] If the start-up conditions are met, the compressor start-up mode is selected according to the magnitude of the cooperative readiness index, and the start-up operation is performed. After the start-up is completed, the system switches to normal operating mode, the preheating device is deactivated, and the standard control program is restored.

[0009] Furthermore, the raw temperature signals include temperature signals from the bottom of the compressor, the bottom of the gas-liquid separator, and the evaporator inlet. The temperature signal from the bottom of the compressor is used to represent the actual metal shell temperature at the bottom of the compressor cavity; the temperature signal from the bottom of the gas-liquid separator is used to sense the thermal changes in the metal area immediately below the oil return hole; and the temperature signal from the evaporator inlet is used to measure the initial temperature of the hot water circulation system entering the evaporator.

[0010] Furthermore, the steps for determining whether the lubricating oil is activated as a flow-like state include: calculating the temperature rise rate of the bottom of the gas-liquid separator per unit time; if the temperature reaches a threshold and the temperature rise rate is lower than a set threshold, then the lubricating oil is determined to be activated as a flow-like state.

[0011] Furthermore, a thermal imbalance suppression term is introduced into the pre-position opening calculation of the electronic expansion valve to suppress the sudden flow rate caused by the temperature difference between the compressor and the gas-liquid separator.

[0012] Furthermore, the establishment of the micro-pressure differential depends on the geometric height difference between the liquid reservoir and the gas-liquid separator and the pipeline resistance, and is estimated using calibration coefficients.

[0013] Furthermore, the construction of the collaborative readiness index includes: weighting and synthesizing the micro-pressure differential amplitude, oil return status, and pressure differential change rate; if the index continuously exceeds the threshold and remains so for a certain period of time, it is determined that the start-up conditions are met.

[0014] Furthermore, the startup modes include standard startup and delayed soft startup, with the startup method selected based on the ratio of the co-readiness index to a threshold.

[0015] Furthermore, if the ratio is less than 1, a delayed soft start method is adopted to gradually increase the compressor voltage; if the ratio is equal to or greater than 1, a direct standard start method is adopted.

[0016] Furthermore, the method achieves closed-loop control of the entire process without relying on additional pressure or flow sensors before the compressor starts, solely through temperature signals and valve control.

[0017] A second aspect of the invention provides a multi-stage preheating-based ultra-high temperature heat pump start-up coordinated control system, the system comprising:

[0018] The zone preheating module is used to collect the raw temperature signal and compare it with the preset start-up threshold. If any temperature fails to meet the standard, the corresponding heating device is controlled to heat independently until the three temperatures all reach the preset threshold. Based on the temperature and temperature rise rate at the bottom of the gas-liquid separator, it is determined whether the lubricating oil has been activated from a high viscosity state to a flow state.

[0019] The oil return status module is used to calculate the one-time pre-position opening of the electronic expansion valve when the lubricating oil is activated into a flow state, control its opening to establish a micro pressure difference, estimate the size of the micro pressure difference, and determine whether the oil return is completed based on the micro pressure difference.

[0020] The collaborative decision-making module is used to construct a collaborative readiness index based on the micro-pressure difference and oil return status to determine whether the system meets the startup conditions.

[0021] The execution module is used to select the compressor's start-up mode based on the magnitude of the cooperative readiness index if the start-up conditions are met, and to perform the start-up operation; after the start-up is completed, it switches to the normal system operation mode, deactivates the preheating device, and restores the standard control program.

[0022] The beneficial technical effects of the present invention are at least as follows:

[0023] To address the aforementioned problems, this invention provides a multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control system and method. By collecting and preheating temperatures at multiple points—the bottom of the compressor, the bottom of the gas-liquid separator, and the evaporator inlet—and combining this with the temperature rise rate, the system determines whether the oil film has truly transitioned from a high-viscosity state to a fluid state, thus obtaining a more realistic oil film activation state before startup. Based on the premise of oil film activation, the controller calculates the one-time micro-opening pre-position of the electronic expansion valve, introduces a thermal imbalance suppression term to avoid sudden inrush flow, and utilizes the height difference between the liquid receiver and the gas-liquid separator to establish a slight pressure difference, completing the induced return flow of lubricating oil without starting the compressor. Subsequently, by constructing a collaborative readiness index that includes the pressure difference amplitude, oil return state, and its stability, a comprehensive judgment across the three physical fields of heat, pressure, and oil is achieved, ensuring that a start-up signal is issued only when all conditions are stably met. Finally, by combining the synergy index with the startup execution method, a startup execution factor is introduced to determine the actual power-up mode of the compressor. When conditions are just met, a delayed or soft start is used; when sufficient margin is available, it directly enters standard startup. During the switching process, system operating parameters are gradually restored, allowing the entire heat pump system to smoothly enter stable operating conditions. This innovative solution, without altering the main unit's hardware structure, utilizes existing sensors and valves to achieve closed-loop control throughout the entire process, including multi-point preheating, oil film activation determination, oil return channel establishment, synergy state determination, and execution switching. This truly matches the physical properties of the R1233zd refrigerant and significantly improves the safety and reliability of system startup. Attached Figure Description

[0024] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0025] Figure 1 This is a flowchart of the collaborative control method for starting up an ultra-high temperature heat pump based on multi-stage preheating, as described in this invention.

[0026] Figure 2 This is a framework diagram of the ultra-high temperature heat pump start-up collaborative control system based on multi-stage preheating according to the present invention. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In one or more embodiments, such as Figure 1 As shown, a collaborative control method for starting up an ultra-high temperature heat pump based on multi-stage preheating is disclosed, the method comprising the following:

[0029] S1: Collect the raw temperature signal and compare it with the preset start-up threshold; if any temperature fails to meet the standard, control the corresponding heating device to heat independently until all three temperatures reach the preset threshold; based on the temperature at the bottom of the gas-liquid separator and the temperature rise rate, determine whether the lubricating oil has been activated from a high viscosity state to a flow state.

[0030] Specifically, in the non-operational state, the R1233zd heat pump system, because the refrigerant is still liquid at room temperature, easily forms a liquid stagnation layer at the bottom of the compressor, the gas-liquid separator, and one side of the evaporator. In addition, the lubricating oil used has high viscosity and poor fluidity at room temperature. Therefore, a "multi-point thermal activation" operation must be performed before the compressor starts. The core objective of this operation is to ensure that the three key nodes of the system—the compressor cavity (to prevent liquid slugging), the bottom of the gas-liquid separator (to clear the oil return path), and the evaporator inlet (to improve initial heat exchange capacity)—each reach an independent thermally stable state. Simultaneously, it determines whether the lubricating oil has been activated from a high-viscosity state to a flowable state, providing a guarantee for oil return control and differential pressure establishment in subsequent operations.

[0031] The initial input for this step consists of three temperature sensor signals: thermocouples mounted on the bottom casing of the compressor. A thermocouple is used to collect the actual metal shell temperature at the bottom of the compressor cavity; the thermocouple is installed on the bottom side wall of the gas-liquid separator. A thermistor used to sense thermal changes in the metal area immediately below the oil return hole; and a thermistor attached to the copper tube at evaporator port C (water inlet). This system is used to measure the initial temperature of the hot water circulating system entering the evaporator. All sensor signals are fed into the main control board via an A / D module, with the numerical format uniformly set to 32-bit floating-point and an update cycle of once per second. To ensure stable temperature response, each reading undergoes a 3-second moving average filter to reduce external interference errors.

[0032] The control motherboard first , and Each value is compared to a preset start-up threshold. The bottom of the compressor must reach... The bottom of the gas-liquid separator needs to meet the following requirements: The evaporator inlet water temperature needs to reach... If any temperature fails to meet the target, the system remains in a "preheating" state and controls the corresponding heating unit to operate based on the failed temperature: when If the standard is not met, the heating element will be powered on to heat the bottom of the compressor; If the standard is not met, heating belt two will operate; If the temperature does not meet the standard, the linked water pump and the electric heating element in the water tank will send hot water into the evaporator to raise the inlet water temperature. It is worth noting that the heating methods of the three zones operate independently and do not interfere with each other. The main control program controls the opening and closing of the zones according to the real-time temperature.

[0033] In determining whether the lubricating oil at the bottom of the gas-liquid separator has fluidity, relying solely on temperature... The absolute value is insufficient. This is because, structurally, oil often stagnates near the bottom return port, and heat conduction is delayed; if at this time… If the temperature has just been reached, but the oil layer has not yet completed thermal penetration, a false impression may appear that the oil has not been activated despite the temperature being within the acceptable range. Therefore, this step introduces a temperature rise rate criterion. It is used to help determine whether the oil film is truly activated.

[0034] ;

[0035] in, This indicates the rate of temperature rise at the bottom of the gas-liquid separator per unit time. Processed at the current moment Moving average Set the time window for rate calculation to 30 seconds.

[0036] Combination and The oil film activation state variable is defined by the following conditions. :

[0037] ;

[0038] in, This is a Boolean variable, indicating whether the lubricating oil changes from a high-viscosity state to a fluid state; It is the rate threshold for oil film activation, set to 0.03.

[0039] Specifically, in this embodiment, the current It has risen to 49.8, and Within seconds The growth is 0.4, then ,judge If the temperature rise rate is greater than 0.05, the oil layer is considered to be activated; if the temperature rise rate is still greater than 0.05, the oil layer has not been sufficiently heated and heating needs to continue.

[0040] Ultimately, when , , and At this point, the control system enters the next stage of operation.

[0041] S2: When the lubricating oil is activated into a flow state, calculate the one-time pre-position opening of the electronic expansion valve, control its opening to establish a micro pressure difference, estimate the size of the micro pressure difference, and determine whether the oil return is completed based on the micro pressure difference;

[0042] Specifically, this step, without the compressor starting, uses the thermal target achievement and oil film activation results from step one as the sole triggering conditions. Utilizing the slight pre-positioning of the electronic expansion valve (EEV) and the system's geometric liquid level difference, a low-disturbance channel and a controllable micro-pressure difference are constructed. This allows the lubricating oil at the bottom of the gas-liquid separator to return to the compressor cavity via the return oil hole and the three-way valve, completing the oil film return before startup. The unique aspect here is that R1233zd is liquid at room temperature and has high viscosity. Without a channel and micro-pressure difference, the oil easily stagnates at the bottom of the separator; however, prematurely opening the valve to a large degree can easily cause sudden changes in low-pressure side and false alarms.

[0043] Confirming the control motherboard , , All reached the corresponding threshold and Then, calculate the one-time pre-position opening degree. The opening degree is then written to the stepper drive chips of EEV1 and EEV2 (the pulse count is converted according to the percentage of the valve's full stroke, and is retained after writing without secondary adjustment). The calculation of the pre-positioned opening degree incorporates a "thermal imbalance suppression term," which automatically converges the opening degree when the temperature has reached the target but a temperature difference still exists between the two key chambers, avoiding sudden inrush flow when the temperature is not fully balanced. The formula is as follows:

[0044] ;

[0045] in, The opening ratio for a single pre-position of the EEV (a dimensionless value with a full stroke of 1). Used to directly set the opening to zero when the oil film is not activated; Three temperature threshold constants set at the factory; the three ratios are normalized according to the thresholds to ensure numerical consistency. The constraint opening degree shall not exceed the "thermal completion degree" of the weakest link; difference term This is a term for suppressing thermal imbalance, with a coefficient of... To solidify the penalty weight, its function is to suppress excessively rapid channel opening when a residual temperature difference exists between the compressor chamber and the separator chamber. For example: if The ratio of the three terms is approximately Take the minimum value approximately The difference term is approximately Corresponding punishment ,get ,like Then the value will be preset accordingly.

[0046] EEV press After pre-positioning, a determinable micro-pressure differential is established under low disturbance by relying on the equivalent geometric height of the reservoir relative to the separator and the pipeline resistance. For ease of engineering implementation, a geometric-operating condition coefficient synthesized through bench calibration is used. (The liquid phase density, gravity, equivalent height, and minimum flow section resistance are converted into a single coefficient and stored in the motherboard's non-volatile memory), and the magnitude of the resulting micro-pressure difference is estimated in a one-time manner:

[0047] ;

[0048] in, The estimated channel pressure value (the calculated dimensions have been normalized through coefficient integration). The factory calibration constant is obtained by fitting the static liquid level difference with the minimum opening flow rate through actual measurements. The control motherboard starts timing after writing the opening value, maintaining the EEV preset and system static time window (e.g., a fixed value of 60 seconds); if no low-pressure side protection trigger occurs within this time window, and If the value is not lower than the fixed threshold (e.g., a fixed value of 150), the channel is considered to be established and has sufficient traction to allow the retained oil to return along the return oil hole—T-junction—return gas line—compressor cavity. In actual execution, no additional pressure or flow sensors are required to avoid structural modifications; the valve opening command is written only once, and this step ends when the time window expires.

[0049] S3: Based on the aforementioned differential pressure and oil return status, construct a collaborative readiness index, and determine whether the startup conditions are met based on the collaborative readiness index;

[0050] Specifically, this step is executed after the first two steps. Its goal is to uniformly determine whether oil film reflux is complete and whether a micro-pressure differential has been effectively established, and to convert the results into a compressor start-up release command. Unlike traditional logic that relies solely on temperature compliance, this step outputs the results from step two. and As the sole input for judgment, combined with a timing-maintaining mechanism and a special regularization term, it ensures that the pressure difference is not formed instantaneously in a pulsed manner, but rather exists stably and truly, while simultaneously confirming that the oil film has successfully returned to the compressor cavity. The significance of this is that, in this embodiment, the R1233zd refrigerant is liquid at room temperature and the oil viscosity is high. If only temperature is considered, the risk of a false pressure difference or premature start-up before the oil film has returned cannot be avoided.

[0051] The control motherboard received and Afterwards, instead of immediately issuing a start command, a cooperative readiness index is first constructed. This index is used to determine the stability of differential pressure and oil return conditions. It not only considers... The amplitude is also considered, and a rate-of-change suppression term is introduced to prevent the system from being misjudged as meeting the condition due to pressure transients. The formula is as follows:

[0052] ;

[0053] in, For the Cooperative Readiness Index; This is the minimum effective differential pressure threshold (calibrated in bench tests, for example, a fixed value of 150). , , The weighting coefficients are optimized through prototype experiments (e.g., 0.7, 0.3, 0.05). for In the judgment time window The normalized rate of change within is defined as:

[0054] ;

[0055] in, To control the motherboard's built-in timing constant (e.g., 30 seconds). If within this time window... If it continues to fluctuate significantly, then If the value is positive, the inhibitory term increases, preventing misjudgments; if the pressure tends to stabilize, then... Approaching zero, the index value is mainly determined by the differential pressure amplitude and the oil return status.

[0056] The control logic stipulates that when And the determination duration is greater than At that point, assuming the system has stabilized in the three major physical fields of heat, pressure, and oil, the motherboard immediately sends a start signal. Simultaneously, heating belts one and two are shut down, ending the preheating phase. This command directly drives the compressor contactor via the motherboard's digital output interface, putting the compressor into actual operation. The entire process does not undergo dynamic feedback optimization; it relies entirely on a one-time decision execution to ensure reproducible system behavior.

[0057] S4: If the start-up conditions are met, select the compressor start-up mode according to the size of the cooperative readiness index and execute the start-up operation; after the start-up is completed, switch to the normal system operation mode, deactivate the preheating device and restore the standard control program.

[0058] Specifically, the sole task of this step is to process the startup command output in step three. This translates into the actual operation of the compressor, while simultaneously switching the system status from "preheating - oil return preparation" to "normal operation".

[0059] exist At this time, the control board first cuts off the power to heating belt one and heating belt two to prevent the preheating device from continuing to work and causing energy overshoot. Then, the board sends a power-on signal to the compressor contactor through the relay control circuit, energizing and starting the compressor motor. To ensure that this process is physically reproducible and to avoid mechanical shock caused by sudden load application, a start-up execution factor is designed for this step. It is not a new judgment, but a control variable that maps the judgment result to the actual execution method.

[0060] ;

[0061] in, The initiating execution factor is dimensionless. The cooperative readiness index is the output of step three; This is the collaboration threshold (usually 1.0). If If it is significantly higher than the threshold, then A value close to 1 indicates that the compressor can operate directly in the standard start-up mode; if... If it is just close to the threshold, then The value will be less than 1, which controls the motherboard to automatically select the delayed startup mode (e.g., startup delayed by 5 seconds). This mapping ensures that the execution action is closely connected with the previous step's judgment.

[0062] During execution, the motherboard according to Choose different startup curves: When At that time, the compressor is powered on at full voltage; when At this time, the motherboard controls the soft-start module to gradually increase the motor voltage within 2-5 seconds, ensuring that even if the system conditions are just met, there will be no oil film disturbance or low-voltage fluctuation due to instantaneous impact. For example: if the output of step three... ,but The system immediately performs a standard startup; if If it just exceeds the 1.0 threshold, then The motherboard selects to start up gradually with a 5-second delay. Through this mapping, the startup behavior is no longer a single action, but closely depends on the result of the previous judgment, ensuring the closed-loop nature of the control logic.

[0063] After the compressor starts, the control board switches the system operating mode to "normal operation" and unlocks the standard programs for condenser fan, circulating water pump, and EEV opening control, allowing the heat pump to enter a stable thermal cycle. At this point, the entire system officially ends the preheating and oil return phase and enters continuous heating operation.

[0064] In one or more embodiments, such as Figure 2 As shown, a multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control system is disclosed, the system comprising:

[0065] The zone preheating module is used to collect the raw temperature signal and compare it with the preset start-up threshold. If any temperature fails to meet the standard, the corresponding heating device is controlled to heat independently until the three temperatures all reach the preset threshold. Based on the temperature and temperature rise rate at the bottom of the gas-liquid separator, it is determined whether the lubricating oil has been activated from a high viscosity state to a flow state.

[0066] The oil return status module is used to calculate the one-time pre-position opening of the electronic expansion valve when the lubricating oil is activated into a flow state, control its opening to establish a micro pressure difference, estimate the size of the micro pressure difference, and determine whether the oil return is completed based on the micro pressure difference.

[0067] The collaborative decision-making module is used to construct a collaborative readiness index based on the micro-pressure difference and oil return status to determine whether the system meets the startup conditions.

[0068] The execution module is used to select the compressor's start-up mode based on the magnitude of the cooperative readiness index if the start-up conditions are met, and to perform the start-up operation; after the start-up is completed, it switches to the normal system operation mode, deactivates the preheating device, and restores the standard control program.

[0069] It is worth noting that the specific workflow of the ultra-high temperature heat pump start-up collaborative control system based on multi-stage preheating provided in this embodiment of the invention is the same as that of the ultra-high temperature heat pump start-up collaborative control method based on multi-stage preheating described in the above embodiments, and will not be repeated here.

[0070] This invention also provides a multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps described in the above embodiments of the multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control method, for example... Figure 1 The steps S1 to S4 described above; or, when the processor executes the computer program, it implements the functions of each module in the above system embodiments.

[0071] For example, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device.

[0072] The multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device may also include input / output devices, network access devices, buses, etc.

[0073] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. This processor is the control center of the multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control equipment, connecting all parts of the equipment via various interfaces and lines.

[0074] The memory can be used to store the computer program and / or modules. The processor, by running or executing the computer program and / or modules stored in the memory and calling the data stored in the memory, realizes various functions of the multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created based on the operation of the air conditioner controller, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart memory card (SMC), secure digital card (SD), flash memory card, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0075] The module integrated into the multi-stage preheating-based ultra-high temperature heat pump start-up collaborative control device, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0076] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0077] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for the coordinated control of the start-up of an ultra-high temperature heat pump based on multi-stage preheating, characterized in that, The method comprises: Collecting original temperature signals and comparing them with preset starting threshold values; the original temperature signals include temperature signals of the compressor bottom, the bottom of the gas-liquid separator, and the water inlet of the evaporator; the temperature signal of the compressor bottom is used to represent the actual metal shell temperature at the bottom of the compressor cavity; the temperature signal of the bottom of the gas-liquid separator is used to sense the thermal change of the metal area close to the bottom of the oil return hole; and the temperature signal of the water inlet of the evaporator is used to measure the initial temperature of the hot water circulating system entering the evaporator; if any temperature does not reach the preset starting threshold value, the corresponding heating device is independently heated until all temperatures reach the preset starting threshold value; based on the temperature and temperature rise rate of the bottom of the gas-liquid separator, it is judged whether the lubricating oil is activated from a high viscosity state to a flowing state; When the lubricating oil is activated to the flowing state, the pre-position opening degree of the electronic expansion valve is calculated, the pre-position opening degree being the opening degree proportion of the one-time pre-position of the electronic expansion valve; and the electronic expansion valve is controlled to be opened to establish a micro pressure difference, the establishment of the micro pressure difference depending on the geometric height difference between the liquid accumulator and the gas-liquid separator and the pipeline resistance, and being estimated by a calibration coefficient; the size of the micro pressure difference is estimated, and whether the oil return is completed is judged based on the micro pressure difference; Based on the micro pressure difference and the oil return state, a collaborative readiness index is constructed, and whether the starting condition is met is judged based on the collaborative readiness index; the construction of the collaborative readiness index comprises: weighting and integrating the micro pressure difference amplitude, the oil return state, and the pressure difference change rate; if the index continuously exceeds the threshold value and remains for a certain time, it is determined that the starting condition is met; If the starting condition is met, the starting mode of the compressor is selected according to the size of the collaborative readiness index, and the starting operation is performed; after the starting is completed, the system is switched to the normal running mode, the preheating device is released, and the standard control program is restored.

2. The method according to claim 1, characterized in that, The step of judging whether the lubricating oil is activated from a high viscosity state to a flowing state comprises: calculating the temperature rise rate of the temperature at the bottom of the gas-liquid separator in a unit time; if the temperature reaches a threshold value and the temperature rise rate is lower than a set threshold value, it is determined that the lubricating oil has been activated to the flowing state.

3. The method according to claim 1, characterized in that, The electronic expansion valve introduces a thermal imbalance suppression term in the pre-position opening degree calculation, which is used to suppress the flow mutation caused by the temperature difference between the compressor and the gas-liquid separator, and the thermal imbalance suppression term is ; wherein, is the temperature of the bottom of the compressor, is the temperature of the bottom of the gas-liquid separator, is a preset starting threshold value of the temperature of the bottom of the compressor, is a preset starting threshold value of the temperature of the bottom of the gas-liquid separator.

4. The method according to claim 1, wherein, The starting mode includes standard starting and delayed soft starting, and the starting mode is selected according to the ratio of the collaborative readiness index to the threshold value.

5. The method according to claim 4, wherein, If the ratio is lower than 1, the delayed soft starting mode is adopted, and the compressor voltage is gradually increased; if the ratio is equal to or higher than 1, the direct standard starting mode is adopted.

6. The method according to claim 1, wherein, Before the compressor starts, no additional pressure or flow sensor is relied on, and only temperature signals and valve control are used to realize full-process closed-loop control.

7. A multi-stage preheating based ultra-high temperature heat pump startup cooperative control system, characterized in that, The system comprises: The partition preheating module is used for collecting original temperature signals and comparing with preset starting threshold values; the original temperature signals include temperature signals of the compressor bottom, the gas-liquid separator bottom and the evaporator water inlet, the temperature signal of the compressor bottom is used for representing the actual metal shell temperature of the compressor cavity bottom, the temperature signal of the gas-liquid separator bottom is used for sensing the heat change of the metal area close to the oil return hole, and the temperature signal of the evaporator water inlet is used for measuring the initial temperature of the hot water circulating system entering the evaporator; if any temperature does not reach the preset starting threshold value, the corresponding heating device is independently heated until all temperatures reach the preset starting threshold value; based on the temperature and temperature rise rate of the gas-liquid separator bottom, it is judged whether the lubricating oil is activated from a high viscosity state to a flow state; The oil return state module is used for calculating the pre-position opening degree of the electronic expansion valve when the lubricating oil is activated to the flow state, the pre-position opening degree is the opening degree proportion of the one-time pre-position of the electronic expansion valve, and the electronic expansion valve is controlled to be opened to establish a micro pressure difference, the establishment of the micro pressure difference depends on the geometric height difference between the liquid accumulator and the gas-liquid separator and the pipeline resistance, and is estimated through a calibration coefficient; the micro pressure difference is estimated, and it is judged whether the oil return is completed based on the micro pressure difference; The cooperative decision module is used for constructing a cooperative readiness index based on the micro pressure difference and the oil return state, judging whether the system meets the starting condition; the construction of the cooperative readiness index includes: weighting and synthesizing the micro pressure difference amplitude, the oil return state and the pressure difference change rate; if the index continuously exceeds the threshold value and remains for a certain time, it is determined that the starting condition is met; The execution module is used for selecting the starting mode of the compressor according to the size of the cooperative readiness index if the starting condition is met, and performing the starting operation; after the starting is completed, the system is switched to the normal running mode, the preheating device is removed and the standard control program is restored.

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