A unit water flow detection method and device and a unit

Abstract

The application discloses a kind of unit no water flow detection method, device and unit.Therein, the method includes: after unit start-up operation, judge shell tube pressure P and shell tube evaporation temperature T 蒸 Whether to meet the first preset condition: P≤P1, or, T 蒸 ≤T1;If meet, determine the time interval t from unit start-up to meet the first preset condition, judge whether to meet: t≤t 设 ;If yes, then the opening of regulating valve is up, and further according to suction temperature T 吸 , shell tube's inlet and outlet water temperature, T 蒸 Identify no water flow fault and execute corresponding protection action;If no, then keep unit normal operation, and according to P and T 吸 Identify no water flow fault and execute corresponding protection action.The application can accurately early warning and protection to unit no water flow operation, avoid shell tube freeze crack by identifying no water flow operation through the operating parameter of unit respectively when unit start-up and during unit operation, and implementing corresponding processing measures.

Description

Technical Field

[0001] This invention relates to the field of generator set technology, and more specifically, to a method, device, and generator set for detecting no water flow in a generator set. Background Technology

[0002] In existing air conditioning chiller units, the shell and tubes often freeze and crack due to the sudden stop of the water pump or the user running the unit without turning on the water pump. Currently, most conventional chiller units only prevent the shell and tubes from freezing by detecting the temperature of the water inside the shell and tubes, without any special protection or control for operation without water flow. The shell and tubes will freeze and crack when the chiller unit is running without water flow.

[0003] There is currently no effective solution to the problem that existing technologies cannot accurately protect and provide precise feedback when the unit is operating without water flow. Summary of the Invention

[0004] This invention provides a method, device, and unit for detecting no water flow in a generating unit, in order to solve the problem that existing technologies cannot accurately protect and provide precise feedback when a generating unit is operating without water flow.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for detecting no water flow in a generating unit, wherein the method includes:

[0006] After the unit is started up and running, determine the shell and tube pressure P and the shell and tube evaporation temperature T. 蒸 Does it satisfy the first preset condition: P≤P1, or, T 蒸 ≤T1; where P1 is the first threshold of shell and tube pressure, and T1 is the first threshold of shell and tube evaporation temperature;

[0007] When the first preset condition is met, the time interval t from the start-up of the unit to the fulfillment of the first preset condition is determined, and it is judged whether the following condition is satisfied: t ≤ set initial running length t 设 ;

[0008] If so, adjust the opening of the upper regulating valve, and further adjust according to the intake temperature T. 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions; wherein, the throttle valve is installed on the pipeline between the shell tube and the condenser;

[0009] If not, then maintain unit operation and, during unit operation, follow the P and T guidelines. 吸 Identify the no-water-flow fault and execute the corresponding protection action.

[0010] Furthermore, determine P and T 蒸 After determining whether the first preset condition is met, the method further includes: if the first preset condition is not met, then maintaining normal operation of the unit.

[0011] Furthermore, based on the inhalation temperature T 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions, including:

[0012] Test P and T again 蒸 And determine whether the first preset condition is met; if so, then detect T. 吸 The intake temperature change data is obtained, the inlet and outlet water temperatures are detected to obtain the inlet and outlet water temperature difference, and based on the intake temperature change data, the inlet and outlet water temperature difference, and T... 蒸 Identify the no-water-flow fault and execute the corresponding protection action; otherwise, maintain normal unit operation.

[0013] Furthermore, based on the intake temperature change data, the inlet and outlet water temperature difference, and T... 蒸 Identify no-water-flow faults and execute corresponding protection actions, including:

[0014] Determine if the second preset condition is met: the change in intake temperature is less than or equal to the first preset data, and the temperature difference between inlet and outlet water is T. 差 ≤T 设 Among them, T 设 This is the limit value for the temperature difference between the inlet and outlet water;

[0015] If the second preset condition is met, then at t 设 The internal judgment determines whether the third preset condition is satisfied: P≤P2, or, T 蒸 ≤T2; where P2 is the second threshold of shell and tube pressure, T2 is the second threshold of shell and tube evaporation temperature, P2<P1, T2<T1; if yes, the unit is controlled to stop, a no-water-flow fault is reported, and the no-water-flow protection action is activated; if no, the unit is controlled to standby, and restarts after the compressor reaches the preset shutdown time.

[0016] If the second preset condition is not met, then the opening of the upper regulating valve will be adjusted at t. 设 The system internally determines whether the third preset condition is met; if so, it controls the unit to stop, reports a no-water-flow fault, and initiates low-pressure protection; if not, it maintains normal unit operation and, during normal unit operation, adjusts the settings according to P and T. 吸 Identify the lack of water flow fault.

[0017] Furthermore, after the control unit is in standby mode and the compressor restarts after a preset shutdown time, the method further includes: after the cumulative number of restarts reaches a preset number, controlling the unit to stop, reporting a no-water-flow fault, and activating the no-water-flow protection action.

[0018] Furthermore, the no-water-flow protection action includes: preventing the compressor from starting automatically, requiring manual clearing of the fault; the low-pressure protection action includes: automatically clearing the fault and restarting the compressor after the preset shutdown time is reached.

[0019] Furthermore, during normal unit operation, according to P and T 吸 Identify no-water-flow faults and execute corresponding protection actions, including:

[0020] The shell and tube pressure P is detected; if P ≤ P1, it is determined whether there was a throttle valve closing action within time t1 before the current time; where t1 is a preset value; if there was no closing action, it is further determined whether the water pump signal is on; if the water pump signal is on, then based on P and T... 吸 Identify the no-water-flow fault and execute the corresponding protection action.

[0021] Furthermore, if the water pump signal is activated, then according to P and T... 吸 Identify no-water-flow faults and execute corresponding protection actions, including:

[0022] Determine if the fourth preset condition is met: P≤P2, and the intake temperature change data > the second preset data; if so, control the compressor to shut down, report a no-water-flow fault: water pump failure or water pump blockage, and activate the no-water-flow protection action; if not, adjust the opening of the flow regulating valve, then re-detect P, and re-determine whether P≤P1 is met.

[0023] Furthermore, after further determining whether the water pump signal is connected, the method also includes: if the water pump signal is not connected, controlling the compressor to shut down and reporting a no-water-flow fault: the water pump is not turned on.

[0024] Furthermore, after determining whether there was a small closing action of the throttle valve within time t1 before the current time, the method further includes: if there was a small closing action, then maintaining normal operation of the unit to confirm that there is no abnormality in the unit.

[0025] The present invention also provides a device for detecting no water flow in a generating unit, wherein the device comprises:

[0026] The detection module is used to determine the shell and tube pressure P and shell and tube evaporation temperature T after the unit is started up and running. 蒸 Does it satisfy the first preset condition: P≤P1, or, T 蒸 ≤T1; where P1 is the first threshold of shell and tube pressure, and T1 is the first threshold of shell and tube evaporation temperature;

[0027] The judgment module is used to determine, when the first preset condition is met, the time interval t from the start-up of the unit to the fulfillment of the first preset condition, and to determine whether the following condition is satisfied: t ≤ set initial running length t 设 ;

[0028] The first processing module is used to adjust the opening of the upper flow valve if the judgment result of the judgment module is yes, and further adjust the intake temperature T according to the judgment result of the upper flow valve. 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions; wherein, the throttle valve is installed on the pipeline between the shell tube and the condenser;

[0029] The second processing module is used to maintain the unit's normal operation if the judgment result of the judgment module is negative, and to determine the appropriate parameters based on P and T during the normal operation of the unit. 吸 Identify the no-water-flow fault and execute the corresponding protection action.

[0030] The present invention also provides a unit, wherein the unit includes: a compressor, a condenser, a shell and tube connected in sequence, a throttling valve disposed on a pipeline between the shell and tube and the condenser, and the aforementioned unit no-water-flow detection device.

[0031] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the unit no-water-flow detection method as described above.

[0032] By applying the technical solution of this invention, the absence of water flow can be identified through the unit's operating parameters during startup and operation, and corresponding handling measures can be implemented. This can accurately provide early warning and protection for the absence of water flow, and prevent the shell and tube from freezing and cracking. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the chiller unit system structure according to an embodiment of the present invention;

[0034] Figure 2 This is a flowchart of a method for detecting no water flow in a generator unit according to an embodiment of the present invention;

[0035] Figure 3 This is a flowchart of the water-free operation control during the unit startup process according to an embodiment of the present invention;

[0036] Figure 4 This is a flowchart of the water-free operation control process of the unit during stable operation according to an embodiment of the present invention;

[0037] Figure 5 This is a structural block diagram of a unit without water flow detection device according to an embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0040] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0041] It should be understood that although the terms first, second, third, etc., may be used to describe preset conditions in the embodiments of the present invention, these preset conditions should not be limited to these terms. These terms are only used to distinguish preset conditions. For example, without departing from the scope of the embodiments of the present invention, the first preset condition may also be referred to as the second preset condition, and similarly, the second preset condition may also be referred to as the first preset condition.

[0042] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0043] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0044] The optional embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0045] Example 1

[0046] Figure 1 This is a schematic diagram of the chiller system structure according to an embodiment of the present invention, such as... Figure 1 As shown, the chiller unit includes at least a compressor 1, a condenser 2 (i.e., a condensing-side heat exchanger), and a shell and tube 4 (i.e., an evaporating-side heat exchanger) connected in sequence. Figure 1 The diagram shows the inlet and outlet of the shell and tube 4, with the inlet near the compressor 1 and the outlet near the condenser 2. The chiller unit also includes a throttling valve 3 (i.e., a throttling device) installed on the pipeline between the shell and tube 4 and the condenser 2.

[0047] According to an embodiment of the present invention, a method for detecting no water flow in a unit is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0048] Figure 2 This is a flowchart of a unit no-water-flow detection method according to an embodiment of the present invention, as follows: Figure 2 As shown, the method includes the following steps:

[0049] Step S201: After the unit is started up and running, determine the shell and tube pressure P and the shell and tube evaporation temperature T. 蒸 Does it satisfy the first preset condition: P≤P1, or, T 蒸 ≤T1.

[0050] Wherein, P1 is the first threshold pressure of the shell and tube, which is usually set to 270kPa to 300kPa for screw chillers (the setting varies depending on the type of unit and compressor). T1 is the first threshold temperature of the shell and tube evaporation, which is usually set to -2℃ to 0.5℃ for screw chillers (the setting varies depending on the type of unit and compressor).

[0051] Step S202: When the first preset condition is met, determine the time interval t from the unit's startup to the fulfillment of the first preset condition, and determine whether the condition is satisfied: t≤t 设 If yes, proceed to step S203; otherwise, proceed to step S204.

[0052] The above t 设 This sets the initial running time, which is typically set to 6 to 10 minutes. This time range ensures the unit starts up and reaches a stable state. If t ≤ t 设 This indicates that the unit is not yet in a stable operating state. Therefore, step S203 is executed to identify and perform protection feedback operations for the unit's no-water-flow operation during startup. If t > t at this time...设 If this indicates that the unit is in a stable operating state, then step S204 is executed to perform the identification and protection feedback operation for the unit's no-water-flow operation during the stable operation period.

[0053] Step S203: Adjust the opening of the upper flow control valve (e.g., increase it by 10%), and further adjust according to the intake temperature T. 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 The system identifies no-water-flow faults and executes corresponding protective actions; the throttle valve is located on the pipeline between the shell and tube and the condenser. Inlet and outlet water temperatures include inlet and outlet water temperatures; the inlet water temperature is detected at the shell inlet, and the outlet water temperature is detected at the shell outlet.

[0054] Step S204: Maintain normal unit operation, and during normal unit operation, according to P and T 吸 Identify the no-water-flow fault and execute the corresponding protection action.

[0055] It should be noted that if the judgment result of step S201 does not meet the first preset condition, it means that the unit is running normally and there are no abnormalities. Then step S205 is executed to keep the unit running normally.

[0056] This embodiment identifies no-water-flow operation by using the unit's operating parameters during startup and operation, and implements corresponding handling measures. It can accurately provide early warning and protection for no-water-flow operation of the unit, and avoid freezing and cracking of the shell and tube.

[0057] 1) The identification and protection feedback operations for the no-water-flow operation during the unit startup period in step S203 will be described in detail below.

[0058] The time interval t from the confirmation of unit startup to the fulfillment of the first preset condition satisfies: t≤t 设 Then, P and T were tested again. 蒸 The system will then determine whether the first preset condition is met. Specifically, it will observe whether the shell-and-tube pressure and shell-and-tube evaporation temperature have improved to avoid false alarms caused by fluctuations during startup.

[0059] If the first preset condition is not met, it means that the unit is in the self-adjustment process and should continue to operate normally.

[0060] If the first preset condition is still met, it indicates that the unit is operating abnormally and it is necessary to test the parameters related to no water flow: Test T 吸 Obtain the intake temperature change data (e.g., intake temperature change rate, intake temperature drop, etc.), detect the inlet and outlet water temperatures to obtain the inlet and outlet water temperature difference (inlet and outlet water temperature difference = inlet water temperature - outlet water temperature), and based on the intake temperature change data, inlet and outlet water temperature difference, and T... 蒸Identify the no-water-flow fault and execute the corresponding protection action. Specifically:

[0061] Determine if the second preset condition is met: the change in intake temperature is less than or equal to the first preset data, and the temperature difference between inlet and outlet water is T. 差 ≤T 设 Among them, T 设 It is the limit value for the temperature difference between the inlet and outlet water.

[0062] In this embodiment, the inhalation temperature change data is the inhalation temperature change rate ΔT. 吸 Let's take an example. The inhalation temperature change data ≤ the first preset data can be: ΔT 吸 ≤ΔT 设 It should be noted that, based on the current actual operation of the unit without water flow, the temperature change between the inlet and outlet water is not significant when starting up without water flow, therefore the temperature difference between the inlet and outlet water is small. 差 It can be set to 0–0.3℃; the inhalation temperature also does not change much, so the first preset data ΔT 设 It can be set to 1-3℃.

[0063] If the suction temperature change data is a decrease in suction temperature, then the suction temperature change data ≤ the first preset data can be: the decrease in suction temperature within 3 minutes ≤ 10~15℃. It should be noted that, according to actual conditions, during normal unit startup, the initial suction temperature detected is the ambient temperature. Therefore, after the compressor starts, the water flow in the evaporator for heat exchange will quickly lower the suction temperature. Thus, the suction temperature will generally decrease by at least 15℃ within 3 minutes of startup.

[0064] If the second preset condition is met, then within a preset time period, determine whether the third preset condition is met: P≤P2, or, T 蒸 ≤T2; If yes, the control unit will stop, report a no-water-flow fault, and activate the no-water-flow protection action; if no, the control unit will standby, and will restart after the compressor reaches the preset shutdown time. After the cumulative number of restarts reaches the preset number, the control unit will stop, report a no-water-flow fault, and activate the no-water-flow protection action.

[0065] P2 is the second threshold pressure of the shell and tube, also known as the protection pressure point. It is usually set within the range of 180 kPa to 230 kPa (the setting varies depending on the type of unit and compressor), and P2 < P1. T2 is the second threshold temperature of the shell and tube evaporator, usually set within the range of -15℃ to -6℃ (the setting varies depending on the type of unit and compressor), and T2 < T1.

[0066] If the second preset condition is not met, it indicates that the parameter change is caused by normal unit adjustment. The opening of the upper regulating valve is then adjusted within a preset time to determine if the third preset condition is met. If yes, the unit is shut down, a no-water-flow fault is reported, and the low-pressure protection is activated. If no, the unit continues normal operation, and during normal operation, adjustments are made based on P and T. 吸 Identify no-water-flow faults, that is, perform identification and protection feedback operations for no-water-flow operation during the stable operation of the unit.

[0067] It should be noted that the above-mentioned no-water-flow protection actions include: preventing the compressor from starting automatically, requiring manual clearing of the fault; this situation occurs when there is no water flow but the water temperature inside the shell and tube is high. The above-mentioned low-pressure protection actions include: automatically clearing the fault and restarting the compressor after the preset shutdown time has elapsed.

[0068] The above describes the identification and protection feedback operations for no-water-flow operation during unit startup. When the unit is started, parameters such as the temperature difference between the inlet and outlet water and the rate of change of the intake air temperature are detected, and the shell and tube pressure and shell and tube evaporation temperature threshold are determined. The throttling device (throttle valve) is adjusted to verify whether no-water-flow phenomenon occurs, and the unit operation is controlled, faults are reported, and protection operations are executed in a timely manner.

[0069] 2) The identification and protection feedback operations for the no-water-flow operation during the stable operation of the unit in step S204 are described in detail below.

[0070] Within the time interval t from the confirmation of unit startup to the fulfillment of the first preset condition, the following condition is satisfied: t > t 设 Next, the process of identifying and protecting the unit during its stable operation phase without water flow is explained as follows:

[0071] Detect shell and tube pressure P;

[0072] When P≤P1 is detected, it is determined whether the throttle valve has been partially closed within t1 seconds before the current time; where t1 is a preset value. The adjustment of the throttle valve will cause fluctuations in the shell and tube pressure, which will usually be reflected within 10s to 20s after the adjustment. Therefore, the range of t1 can be set to 10s to 20s.

[0073] If the minor operation is caused by the throttle valve adjustment, then maintain normal unit operation, confirm that there are no abnormalities in the unit, and do not perform any tests related to no-flow.

[0074] If no small action is performed, a no-water-flow test is required: determine if the water pump signal is connected. If the water pump signal is not connected, control the compressor to shut down and report a no-water-flow fault: the water pump is not running.

[0075] If the water pump signal is on, then according to P and T吸 Identify the no-water-flow fault and execute the corresponding protection action. Specifically: Determine if the fourth preset condition is met: P≤P2, and the suction temperature change data > the second preset data. If met, control the compressor to shut down, report the no-water-flow fault: water pump failure or water pump blockage, and activate the no-water-flow protection action. If not met, adjust the opening of the flow regulating valve, then re-detect P, and re-determine if P≤P1 is met.

[0076] The above-mentioned inhalation temperature change data can be the inhalation temperature change rate ΔT 吸 It can also be the decrease in suction temperature. If the change in suction temperature is the decrease in suction temperature, then the change in suction temperature > the second preset data can be: the decrease in suction temperature within 1 minute > 10℃. It should be noted that, according to the actual situation, in this kind of operation, because the water temperature is already at a low level, if the water is cut off at this time, the refrigerant cannot fully exchange heat, thus rapidly lowering the suction temperature.

[0077] The above describes the identification and protection feedback operations for waterless operation during stable unit operation. During stable unit operation, different faults are distinguished and fed back based on low pressure changes, throttle valve adjustment, and pump status, ensuring that unit operation is not disturbed and that abnormal conditions are protected in a timely manner.

[0078] This embodiment detects low pressure and evaporation temperature after unit startup and compares them with relevant data to initially identify the risk of no-water-flow operation. It then monitors changes in inlet and outlet water temperature differences and intake temperature to provide verification and judgment. Further comparison with relevant data accurately identifies the no-water-flow phenomenon and issues a warning feedback. During stable unit operation, it distinguishes the impact of throttle valve operation on the unit and further determines the no-water-flow fault by analyzing pressure and intake temperature changes during operation, executing protection feedback operations. This solves the problem in existing technologies where accurate protection and precise feedback are not possible during no-water-flow operation.

[0079] Example 2

[0080] Figure 3 This is a flowchart illustrating the water-free operation control process during unit startup according to an embodiment of the present invention, as shown below. Figure 3 As shown, the process includes the following steps:

[0081] Step S301: During the unit startup process, the unit's shell and tube pressure P and shell and tube inlet and outlet water temperatures T are simultaneously monitored. 进 T 出 Intake temperature T 吸 Shell and tube evaporation temperature T 蒸 Simultaneously determine whether P ≤ P1, or T 蒸 Is it ≤ T1?

[0082] P1 is the first threshold pressure for shell and tube pressure, typically set to 270 kPa to 300 kPa for screw chillers (the setting varies depending on the type of chiller and compressor). P2 is the second threshold pressure for shell and tube pressure, also known as the protection pressure point, typically set between 180 kPa and 230 kPa (the setting varies depending on the type of chiller and compressor). T1 is the first threshold temperature for shell and tube evaporation, typically set to -2℃ to 0.5℃ for screw chillers (the setting varies depending on the type of chiller and compressor). T2 is the second threshold temperature for shell and tube evaporation, typically set between -15℃ and -6℃ (the setting varies depending on the type of chiller and compressor).

[0083] If P≤P1 or T is not satisfied 蒸 If the value is less than or equal to T1, the unit starts up normally without any abnormalities and continues to operate; if the condition is met, proceed to step S302.

[0084] Step S302, detect if P≤P1 or T 蒸 The time t that the time group has been running is ≤T1.

[0085] a. If t > t 设 (t 设 To set the initial running time, typically ranging from 6 to 10 minutes, this time range ensures the unit starts up and reaches a stable state (i.e., the unit is already in a stable operating state). If a situation of no water flow does occur at this point, the following steps will be executed. Figure 4 The control flow within.

[0086] b. If this phenomenon occurs during the initial operating time of the unit, increase the opening of the throttle valve by 10% and check whether the shell and tube pressure and evaporation temperature improve, in order to avoid false alarms caused by fluctuations during the start-up process.

[0087] Step S303: After opening the throttle valve, check again whether P ≤ P1 or T 蒸 ≤T1.

[0088] a. If the conditions are not met, the unit is in the self-adjustment process and will continue to operate in the absence of water flow.

[0089] b. If at this point P ≤ P1 or T still holds true 蒸 ≤T 1， If the unit is operating abnormally, the relevant parameters for no water flow will be checked, and the process will proceed to step S304.

[0090] Step S304: Detect the temperature difference T between the inlet and outlet water. 差 Detect the rate of change of inhalation temperature ΔT 吸 Determine whether T is satisfied. 差 ≤T 设 And ΔT 吸≤ΔT 设 .

[0091] Based on the current actual operation of the unit without water flow, the changes in inlet and outlet water temperature are not significant when starting up without water flow, so the temperature difference between inlet and outlet water is small. 差 It can be set to 0–0.3℃. The intake temperature also doesn't change much, so the intake temperature ΔT 设 It can be set to 1-3℃.

[0092] a. If the condition is not met, it is determined that the unit is undergoing normal adjustment, and then the process enters control mode 5.

[0093] b. If satisfied, then further determine t. 设 Does P ≤ P2 or T? 蒸 ≤T2.

[0094] b1. If not, the unit will standby and restart after the compressor has been off for the required time. The number of times will be incremented by 1. When the cumulative number of times is 3 (or other values ​​can be set), the unit will report: no water flow protection and the compressor is not allowed to start. The fault must be cleared manually (this is when there is no water flow but the water temperature inside the shell and tube is high).

[0095] b2. If so, the unit will shut down, and the unit will report: no water flow protection, and the compressor is not allowed to start. The fault must be manually cleared.

[0096] Step S305: At this time, the throttle valve opening is increased by 10% again, and t is detected simultaneously. 设 Does P ≤ P2 or T? 蒸 ≤T2.

[0097] a. If so, the unit will shut down and report the fault: activate the low-pressure protection, and automatically clear the fault and restart the unit after the compressor has been shut down for the required time.

[0098] b. If not, the unit is operating normally.

[0099] In the above embodiments, P is the shell and tube pressure, and T is the tube pressure. 进 T is the inlet water temperature of the shell and tube. 出 T is the outlet water temperature of the shell and tube. 吸 T is the intake temperature. 蒸 Let P1 be the shell-and-tube evaporation temperature, P2 be the first low-pressure threshold, P2 be the second low-pressure threshold (P2 < P1), T1 be the first shell-and-tube evaporation temperature threshold, T2 be the second shell-and-tube evaporation temperature threshold, and t be the evaporation temperature. 设 The initial runtime value after power-on, T 差 The temperature difference between inlet and outlet water (T) 差 =T 进 -T 出 ), T 设 ΔT is the limit value for the temperature difference between the inlet and outlet water. 设The preset rate of change for intake temperature is ΔT. 吸 The rate of change of intake temperature (ΔT) 吸 =Inhalation temperature T 10s ago 10s -Current intake temperature T 吸 ).

[0100] This embodiment proposes identification and protection feedback operations for no-water-flow operation during unit startup. When the unit is started, parameters such as the temperature difference between inlet and outlet water and the rate of change of intake air temperature are detected, and the shell and tube pressure and shell and tube evaporation temperature threshold are determined. The throttling device (throttle valve) is adjusted to verify whether no-water-flow phenomenon occurs, and the unit operation is controlled, fault feedback is provided, and protection operations are executed in a timely manner.

[0101] Example 3

[0102] Figure 4 This is a flowchart illustrating the water-free operation control process during stable operation of the unit according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps:

[0103] In step S401, if the unit detects that P≤P1 during operation, it synchronously checks whether the throttle valve has been adjusted or closed within t1 seconds before the time P≤P1. The adjustment of the throttle valve will cause fluctuations in the shell and tube pressure, which will usually be reflected within 10s to 20s after the adjustment. The range of t1 is set to 10s to 20s.

[0104] a. If there is a small adjustment action, the shell and tube pressure fluctuation is caused by the adjustment of the throttling device. In this case, the unit will continue to operate in the current state and will not perform any tests related to no-flow.

[0105] b. If no adjustment action is taken, proceed to step 2 to detect water flow-related parameters during operation.

[0106] Step S402: In this case, first check whether the water pump signal is connected.

[0107] a. If the water pump signal is not connected, immediately control the compressor to shut down and report the fault: water pump not started.

[0108] b. If the water pump signal is already connected, then synchronously check whether P≤P2 and ΔT 吸 >ΔT 设 ;

[0109] b1. If not, then increase the throttle valve opening by 10%, and then return to the detection and judgment in step 1;

[0110] b2. If so, immediately shut down the compressor and report the fault: no water flow protection, indicating a water pump malfunction or water circuit blockage.

[0111] This embodiment proposes identification and protection feedback operations for waterless operation during stable unit operation. When the unit is running stably, it distinguishes and feeds back different faults based on low pressure changes, throttle valve adjustment, and pump status, ensuring that the unit operation is not disturbed and that abnormal conditions are protected in a timely manner.

[0112] Example 4

[0113] Corresponding to Figure 2 The method for detecting no water flow in a generating unit described in this embodiment provides a device for detecting no water flow in a generating unit, such as... Figure 5 The diagram shown depicts the structural block diagram of the unit's no-water-flow detection device. The device includes:

[0114] Detection module 10 is used to determine the shell and tube pressure P and shell and tube evaporation temperature T after the unit is started and running. 蒸 Does it satisfy the first preset condition: P≤P1, or, T 蒸 ≤T1; where P1 is the first threshold of shell and tube pressure, and T1 is the first threshold of shell and tube evaporation temperature;

[0115] The judgment module 20, connected to the detection module 10, is used to determine the time interval t from the start-up of the unit to the fulfillment of the first preset condition when the first preset condition is met, and to determine whether the following condition is satisfied: t ≤ set initial running length t 设 ;

[0116] The first processing module 30 is connected to the judgment module 20. If the judgment result of the judgment module 20 is yes, it adjusts the opening of the flow valve and further adjusts the opening based on the intake temperature T. 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions; the throttle valve is installed on the pipeline between the shell and the condenser;

[0117] The second processing module 40, connected to the judgment module 20, is used to maintain the unit's normal operation if the judgment result of the judgment module 20 is negative, and to determine the appropriate parameters based on P and T during the normal operation of the unit. 吸 Identify the no-water-flow fault and execute the corresponding protection action.

[0118] The unit's no-water-flow detection device in this embodiment can identify no-water-flow operation based on the unit's operating parameters both during unit startup and during unit operation, and implement corresponding handling measures, as described in detail above. Based on this, it can accurately provide early warning and protection against no-water-flow operation, preventing shell and tube freezing and cracking.

[0119] This embodiment also provides a unit, including: a compressor, a condenser, a shell and tube, a throttling valve installed on the pipeline between the shell and tube and the condenser, connected in sequence, and the aforementioned unit no-water-flow detection device. This allows for the identification of no-water-flow operation based on the unit's operating parameters during startup and operation, and the implementation of corresponding handling measures.

[0120] Example 5

[0121] This invention provides software for executing the technical solutions described in the above embodiments and preferred embodiments.

[0122] This invention provides a non-volatile computer storage medium storing computer-executable instructions that can execute the unit no-water-flow detection method in any of the above method embodiments.

[0123] The aforementioned storage medium stores the aforementioned software, and the storage medium includes, but is not limited to, optical discs, floppy disks, hard disks, and rewritable memory.

[0124] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0125] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0127] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0128] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0129] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0130] The above-described product can execute the method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the method provided in the embodiments of the present invention.

[0131] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0132] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This 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 to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting no water flow in a generating unit, characterized in that, The method includes: After the unit is started up and running, determine the shell and tube pressure P and the shell and tube evaporation temperature T. 蒸 Does it satisfy the first preset condition: P≤P1, or, T 蒸 ≤T1; where P1 is the first threshold of shell and tube pressure, and T1 is the first threshold of shell and tube evaporation temperature; When the first preset condition is met, the time interval t from the start-up of the unit to the fulfillment of the first preset condition is determined, and it is judged whether the following condition is satisfied: t ≤ set initial running length t 设 ; If so, adjust the opening of the upper regulating valve, and further adjust according to the intake temperature T. 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions; wherein, the throttle valve is installed on the pipeline between the shell tube and the condenser; If not, then maintain unit operation and, during unit operation, follow the P and T guidelines. 吸 Identify the no-water-flow fault and execute the corresponding protection action.

2. The method according to claim 1, characterized in that, Determine P and T 蒸 After determining whether the first preset condition is met, the method further includes: If the first preset condition is not met, the unit will continue to operate normally.

3. The method according to claim 1, characterized in that, Further based on the inhalation temperature T 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions, including: Test P and T again 蒸 And determine whether the first preset condition is met; If so, then detect T. 吸 The intake temperature change data is obtained, the inlet and outlet water temperatures are detected to obtain the inlet and outlet water temperature difference, and based on the intake temperature change data, the inlet and outlet water temperature difference, and T... 蒸 Identify no-water-flow faults and execute corresponding protection actions; If not, then keep the unit running normally.

4. The method according to claim 3, characterized in that, Based on the air intake temperature change data, the inlet and outlet water temperature difference, and T 蒸 Identify no-water-flow faults and execute corresponding protection actions, including: Determine if the second preset condition is met: the change in intake temperature is less than or equal to the first preset data, and the temperature difference between inlet and outlet water is T. 差 ≤T 设 Among them, T 设 This is the limit value for the temperature difference between the inlet and outlet water; If the second preset condition is met, then at t 设 The internal judgment determines whether the third preset condition is satisfied: P≤P2, or, T 蒸 ≤T2; where P2 is the second threshold of shell and tube pressure, T2 is the second threshold of shell and tube evaporation temperature, P2<P1, T2<T1; if yes, the unit is controlled to stop, a no-water-flow fault is reported, and the no-water-flow protection action is activated; if no, the unit is controlled to standby, and restarts after the compressor reaches the preset shutdown time. If the second preset condition is not met, then the opening of the upper regulating valve will be adjusted at t. 设 The system internally determines whether the third preset condition is met; if so, it controls the unit to stop, reports a no-water-flow fault, and initiates low-pressure protection; if not, it maintains normal unit operation and, during normal unit operation, adjusts the settings according to P and T. 吸 Identify the lack of water flow fault.

5. The method according to claim 4, characterized in that, After the control unit is in standby mode and the compressor restarts after a preset shutdown time, the method further includes: After the cumulative number of restarts reaches the preset number, the control unit will stop, report a no-water-flow fault, and activate the no-water-flow protection action.

6. The method according to claim 4, characterized in that, The no-water-flow protection action includes: preventing the compressor from starting automatically, and requiring manual clearing of the fault; The low-pressure protection action includes: automatically clearing the fault and restarting the compressor after the preset shutdown time has been reached.

7. The method according to claim 1, characterized in that, According to P and T during normal unit operation 吸 Identify no-water-flow faults and execute corresponding protection actions, including: Detect shell and tube pressure P; When P≤P1 is detected, it is determined whether there was a throttle valve closing action within t1 time before the current time; where t1 is a preset value. If no small action is performed, further check if the water pump signal is on; if the water pump signal is on, then determine the P and T signals. 吸 Identify the no-water-flow fault and execute the corresponding protection action.

8. The method according to claim 7, characterized in that, If the water pump signal is on, then according to P and T 吸 Identify no-water-flow faults and execute corresponding protection actions, including: Determine whether the fourth preset condition is met: P≤P2, and the inhalation temperature change data > the second preset data; If so, control the compressor to shut down and report a no-water-flow fault: water pump failure or water pump blockage, and activate the no-water-flow protection action; If not, adjust the opening of the flow control valve, then re-detect P and re-determine whether P≤P1 is satisfied.

9. The method according to claim 7, characterized in that, After further determining whether the water pump signal is connected, the method also includes: If the water pump signal is not connected, the compressor will be shut down, and a no-water-flow fault will be reported: the water pump is not turned on.

10. The method according to claim 7, characterized in that, After determining whether the throttle valve closed within time t1 prior to the current time, the method further includes: If any minor issues arise, continue operating the unit normally and confirm that there are no abnormalities.

11. A device for detecting no water flow in a generating unit, characterized in that, The device includes: The detection module is used to determine the shell and tube pressure P and shell and tube evaporation temperature T after the unit is started up and running. 蒸 Does it satisfy the first preset condition: P≤P1, or, T 蒸 ≤T1; where P1 is the first threshold of shell and tube pressure, and T1 is the first threshold of shell and tube evaporation temperature; The judgment module is used to determine, when the first preset condition is met, the time interval t from the start-up of the unit to the fulfillment of the first preset condition, and to determine whether the following condition is satisfied: t ≤ set initial running length t 设 ; The first processing module is used to adjust the opening of the upper flow valve if the judgment result of the judgment module is yes, and further adjust the intake temperature T according to the judgment result of the upper flow valve. 吸 Inlet and outlet water temperatures of the shell and tube, T 蒸 Identify no-water-flow faults and execute corresponding protection actions; wherein, the throttle valve is installed on the pipeline between the shell tube and the condenser; The second processing module is used to maintain the unit's normal operation if the judgment result of the judgment module is negative, and to determine the appropriate parameters based on P and T during the normal operation of the unit. 吸 Identify the no-water-flow fault and execute the corresponding protection action.

12. A generator unit, characterized in that, The unit includes: a compressor, a condenser, a shell and tube connected in sequence, a throttling valve disposed on the pipeline between the shell and tube and the condenser, and the unit no-water-flow detection device as described in claim 11.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 10.

Images