Method and system for controlling drainage temperature of heat supply network of combined cycle heat supply unit

Abstract

The invention provides a combined cycle heat supply unit heat supply network drain water temperature control method and system. The method comprises the steps that the heat supply network drain water actual measurement temperature which is collected by a temperature measuring element and is about to enter a condensation water system is obtained; calculating a temperature deviation value between the actually measured temperature of the heat supply network drainage and a preset safe temperature of the heat supply network drainage; based on the temperature deviation value and a preset first mapping relation, the demineralized water demand quantity for temperature reduction is determined; wherein the first mapping relationship is used for representing a corresponding relationship between the demanded water quantity and the temperature deviation value; determining a target opening degree of the first electric valve based on the demanded quantity of the desalted water and a preset second mapping relation; wherein the second mapping relation is used for representing the corresponding relation between the opening degree of the first electric valve and the demanded quantity of the demineralized water; and the first electric valve is controlled to act according to the target opening. According to the scheme, accurate control over the drainage temperature is achieved, and then the operation safety of the whole combined cycle heat supply unit is improved.

Description

Technical Field

[0001] The present invention relates to the field of automatic control technology, and in particular to a method and system for controlling the drain water temperature of a heat network of a combined cycle heating unit. Background Art

[0002] Combined cycle heating units are responsible for heating in winter. With the continuous increase of heating area in winter, the safe and stable operation of the heating network system has put forward higher requirements on the safety and stability of the entire combined cycle unit. Especially after the unit enters the back pressure operation mode, the adjustable means of the entire unit will become less and less. At present, the heating process of the combined cycle heating unit is to extract steam from the medium and low pressure main steam connecting pipes, and the steam exchanges heat with the heating network heat exchanger in the heat exchanger to heat the heating network circulating water. The steam after heat exchange becomes the heating network drain, and the heating network drain finally enters the condensate system, specifically enters the front end of the condensate system iron removal filter.

[0003] In actual applications, during the heating process of the combined cycle heating unit, when the heating network is adjusted, or the heating amount is large and the ambient temperature is high, the return water temperature of the entire heating network circulating water is high, resulting in a high drain temperature of the heating network. At this time, the condensate temperature in the entire condensate system will be high. Considering the operating safety of the condensate system, the condensate temperature entering the iron removal filter shall generally not be higher than 80°C. If the drain temperature is too high, it will bring safety hazards to the normal operation of the condensate system.

[0004] Therefore, how to ensure that the heat network drain temperature is within a controllable range is a technical problem that urgently needs to be solved in the industry. Summary of the invention

[0005] The present invention provides a combined cycle heating unit heat network drain temperature control method and system, which are used to solve the defect that the operation safety of the condensate system in the combined cycle heating unit is low due to the uncontrollable drain temperature.

[0006] On the one hand, the present invention provides a combined cycle heating unit heat network drain water temperature control method, which is applied to a combined cycle heating unit including a desalted water system and a condensate water system, wherein a first electric valve is provided on a connecting pipe between the desalted water system and the condensate water system, and a temperature measuring element is provided near a pipe inlet of the condensate water system; the method comprises:

[0007] Obtaining the actual measured temperature of the heat network drain water about to enter the condensate water system collected by the temperature measuring element;

[0008] Calculating the temperature deviation between the actual temperature of the heating network drain and the preset heating network drain safety temperature;

[0009] Based on the temperature deviation value and a preset first mapping relationship, determining the amount of desalted water required for cooling; wherein the first mapping relationship is used to characterize the correspondence between the amount of desalted water required and the temperature deviation value;

[0010] Determine the target opening of the first electric valve based on the desalted water demand and a preset second mapping relationship; wherein the second mapping relationship is used to characterize the corresponding relationship between the opening of the first electric valve and the desalted water demand;

[0011] The first electric valve is controlled to operate according to the target opening.

[0012] According to the combined cycle heating unit heat network drain temperature control method provided by the present invention, the first mapping relationship is established through the following process:

[0013] Obtain the historical temperature sequence of the heat network drain in the combined cycle heating unit;

[0014] According to the heat network drain safety temperature, determine the safety temperature lower limit value and the safety temperature upper limit value respectively, and establish a safety temperature range;

[0015] Extracting a temperature subsequence that satisfies the safety temperature range from the historical temperature sequence;

[0016] Obtaining the amount of deionized water used at each temperature sampling point in the temperature subsequence at the corresponding sampling time;

[0017] Establishing a plurality of two-dimensional data points according to each temperature sampling point in the temperature subsequence and the desalted water usage corresponding to each of the temperature sampling points;

[0018] Fitting processing is performed on the multiple two-dimensional data points to obtain the first mapping relationship.

[0019] According to the combined cycle heating unit heat network drain temperature control method provided by the present invention, the second mapping relationship is established through the following process:

[0020] Under different opening degrees of the first electric valve, calibrate the output of deionized water flowing through the first electric valve to obtain a plurality of two-dimensional calibration points;

[0021] Extracting a plurality of target calibration points where the opening of the first electric valve is within a preset safe opening range from the plurality of two-dimensional calibration points;

[0022] Fitting is performed on the multiple target calibration points to obtain the second mapping relationship.

[0023] According to the combined cycle heating unit heat network drain temperature control method provided by the present invention, a second electric valve is provided on the pipeline from the heat network drain to the condensate system, and the method further includes:

[0024] The temperature deviation value is compared with a preset first deviation threshold value, and when the temperature deviation value is continuously higher than the first deviation threshold value for a preset time period, the opening of the second electric valve is controlled to be reduced to a first safety opening degree.

[0025] According to the method for controlling the drain water temperature of a heat network of a combined cycle heating unit provided by the present invention, the method further comprises:

[0026] The temperature deviation value is compared with a preset second deviation threshold value. When the temperature deviation value is continuously higher than the second deviation threshold value for a preset period of time, a temperature abnormality warning message is generated and issued.

[0027] According to the method for controlling the drain water temperature of a heat network of a combined cycle heating unit provided by the present invention, the method further comprises:

[0028] Respectively obtain a first pressure value of the heat network drain and a second pressure value of the desalted water;

[0029] Comparing the first pressure value with the second pressure value to obtain a comparison result;

[0030] When the comparison result is that the first pressure value is higher than the second pressure value, a pressure abnormality warning message is generated and issued.

[0031] On the other hand, the present invention also provides a combined cycle heating unit heat network drain temperature control system, which is applied to a combined cycle heating unit including a desalted water system and a condensate water system, and the control system includes:

[0032] A temperature measuring element is arranged near the pipe inlet of the condensate water system;

[0033] A first electric valve is provided on a connecting pipe between the desalted water system and the condensate water system;

[0034] A control device is connected to the temperature measuring element and the first electric valve respectively, and the control device is used to:

[0035] Obtain the actual measured temperature of the hot network drain that is about to enter the condensate water system collected by the temperature measuring element; calculate the temperature deviation value between the actual measured temperature of the hot network drain and the preset hot network drain safety temperature; determine the demand for desalted water for cooling based on the temperature deviation value and a preset first mapping relationship; wherein the first mapping relationship is used to characterize the correspondence between the demand for desalted water and the temperature deviation value; determine the target opening of the first electric valve based on the demand for desalted water and a preset second mapping relationship; wherein the second mapping relationship is used to characterize the correspondence between the opening of the first electric valve and the demand for desalted water; and control the action of the first electric valve according to the target opening.

[0036] According to the combined cycle heating unit heat network drain temperature control system provided by the present invention, the system also includes:

[0037] A second electric valve is arranged on a pipeline from the heat network drain to the condensate system, and the second electric valve is connected to the control device;

[0038] The control device is also used for:

[0039] The temperature deviation value is compared with a preset first deviation threshold value, and when the temperature deviation value is continuously higher than the first deviation threshold value for a preset time period, the opening of the second electric valve is controlled to be reduced to a first safety opening degree.

[0040] According to the combined cycle heating unit heat network drain temperature control system provided by the present invention, the system also includes:

[0041] The check valve is arranged on the connecting pipe between the desalted water system and the condensate water system and is located at the rear side of the first electric valve.

[0042] According to the combined cycle heating unit heat network drain temperature control system provided by the present invention, the system also includes:

[0043] The manual valve is arranged on the connecting pipe between the desalted water system and the condensate water system and is located in front of the first electric valve.

[0044] The method and system for controlling the temperature of a heat network drain of a combined cycle heating unit provided by the present invention obtain the actual temperature of the heat network drain that is about to enter the condensate system collected by a temperature measuring element, calculate the temperature deviation value between the actual temperature of the heat network drain and a preset heat network drain safety temperature, and determine the demand for desalted water for cooling based on the temperature deviation value and a preset first mapping relationship, and determine the target opening of the first electric valve based on the demand for desalted water and a preset second mapping relationship, and finally control the action of the first electric valve according to the target opening, thereby solving the problem of low operating safety of the condensate system caused by uncontrollable drain temperature during the heating process of the combined cycle heating unit, achieving precise control of the drain temperature, and thereby improving the operating safety of the entire combined cycle heating unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 It is a flow chart of a method for controlling the temperature of a heat network drain of a combined cycle heating unit provided by an embodiment of the present invention;

[0047] Figure 2 Schematic diagram of the arrangement of key components of the hydrophobic temperature control link in an embodiment of the present invention;

[0048] Figure 3 It is a structural schematic diagram of a heat network drain temperature control system of a combined cycle heating unit provided by an embodiment of the present invention;

[0049] Figure 4 Schematic diagram of the structure of the control device in the embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Combine the following Figures 1 to 4 The detailed scheme of the method and system for controlling the temperature of the heat network drain of a combined cycle heating unit provided in an embodiment of the present invention is described.

[0052] Figure 1 It is a flow chart of a method for controlling the drain water temperature of a heat network of a combined cycle heating unit provided in an embodiment of the present invention.

[0053] like Figure 1 As shown, the combined cycle heating unit heat network drain water temperature control method provided by the embodiment of the present invention can be executed by a control device with data receiving and sending and data processing functions. The method can be applied to a combined cycle heating unit including a desalted water system and a condensate water system. Figure 2 The following is an example of the key components of the heat network drain temperature control link in the combined cycle heating unit, such as Figure 2 As shown, a first electric valve K1 is provided on the connecting pipe between the desalted water system and the condensate water system, and a temperature measuring element P is provided near the pipe inlet of the condensate water system; the method mainly comprises the following steps:

[0054] Step 110: Obtain the actual measured temperature of the heat network drain water that is about to enter the condensate water system collected by the temperature measuring element.

[0055] In practical applications, the temperature measuring element may be one or more temperature sensors. When multiple temperature sensors are provided, the average temperature value measured by the multiple temperature sensors may be used as the actual measured temperature of the heat network drain.

[0056] Step 120: Calculate the temperature deviation between the actual temperature of the heating network drain and the preset heating network drain safety temperature.

[0057] It is understandable that in order to avoid the safety hazard of the condensate water system due to the excessively high temperature of the drain entering the condensate water system, a heating network drain safety temperature can be set in advance. The heating network drain safety temperature is the upper limit of the temperature of the heating network drain. The temperature deviation value can reflect the deviation of the actual measured temperature of the heating network drain from the safety temperature of the heating network drain. The larger the temperature deviation value, the greater the degree of deviation and the higher the control demand.

[0058] In practical applications, the heating network drain safety temperature may be a pre-set temperature value less than or equal to 80°C, for example, the heating network drain safety temperature may be 78°C.

[0059] Step 130: Determine the amount of desalted water required for cooling based on the temperature deviation value and a preset first mapping relationship; wherein the first mapping relationship is used to characterize the correspondence between the amount of desalted water required and the temperature deviation value.

[0060] It is understandable that the demand for desalted water can be directly determined based on the temperature deviation value and the first mapping relationship, and the desalted water with lower temperature can be used to cool the hot network drain water, thereby reducing the drain water temperature flowing into the condensate system.

[0061] Step 140: Determine the target opening of the first electric valve based on the demand for desalted water and a preset second mapping relationship; wherein the second mapping relationship is used to characterize the corresponding relationship between the opening of the first electric valve and the demand for desalted water.

[0062] In this embodiment, after the demand for desalted water is obtained, the preset second mapping relationship can be used to directly obtain the target opening of the first electric valve, thereby controlling the opening of the first electric valve to meet the demand for desalted water in the drain temperature control link.

[0063] Step 150: Control the action of the first electric valve according to the target opening.

[0064] The solution provided in this embodiment can achieve closed-loop control of the heat network drain temperature by controlling the opening of the first electric valve, so that the heat network drain temperature is controlled within a safe range, thereby improving the operating safety of the entire combined cycle heating unit.

[0065] In one embodiment, the first mapping relationship may be established through the following process:

[0066] The first step is to obtain the historical temperature sequence of the heat network drain in the combined cycle heating unit.

[0067] It can be understood that the historical temperature series is a data series consisting of temperature values ​​collected at multiple consecutive sampling moments within a certain period of time.

[0068] The second step is to determine the lower and upper limits of the safety temperature based on the heat network drain safety temperature, and establish a safety temperature range.

[0069] Considering that there are some abnormal data points in the historical temperature series that deviate greatly from the safe temperature of the heat network drain, these abnormal data points are not very useful for data analysis. Therefore, a safe temperature range can be established as a screening condition for high-quality data points.

[0070] In practical applications, a lower limit deviation value and an upper limit deviation value can be set respectively, and the lower limit deviation value can be subtracted from the heating network drain safety temperature to obtain the lower limit value of the safety temperature, and the upper limit deviation value can be summed to obtain the upper limit value of the safety temperature. The safety temperature range can be obtained based on the lower limit value and the upper limit value of the safety temperature.

[0071] The third step is to extract the temperature subsequence that meets the safe temperature range in the historical temperature sequence.

[0072] Data points within the safe temperature range can be defined as high-quality data points. This embodiment extracts high-quality data points that meet the safe temperature range from the historical temperature sequence, thereby obtaining a temperature subsequence.

[0073] In practical applications, in order to ensure the accuracy of subsequent fitting results, after obtaining the temperature subsequence, we can first determine whether the number of data points in the temperature subsequence exceeds the preset number threshold. If the number of data points does not exceed the preset number threshold, new data points are added through data expansion so that the number of data points meets the preset data threshold.

[0074] The fourth step is to obtain the amount of deionized water used at each temperature sampling point in the temperature subsequence at the corresponding sampling time.

[0075] The fifth step is to establish multiple two-dimensional data points according to each temperature sampling point in the temperature subsequence and the desalted water usage corresponding to each temperature sampling point.

[0076] It can be understood that a two-dimensional data point contains the sampling temperature and desalted water usage at the same sampling time. In practical applications, the sampling temperature can be used as the horizontal axis value and the desalted water usage at the same time as the vertical axis value to establish a two-dimensional data point.

[0077] After obtaining multiple two-dimensional data points, error points that obviously deviate from the normal range can be extracted from the two-dimensional data points, and the error points can be eliminated. New replacement points can be added according to actual needs to ensure that the number of two-dimensional data points meets the requirements.

[0078] The sixth step is to perform fitting processing on multiple two-dimensional data points to obtain a first mapping relationship.

[0079] In this embodiment, the first mapping relationship is essentially a two-dimensional function. After the first mapping relationship is established, the demand for desalted water can be directly determined according to the temperature deviation value.

[0080] In one embodiment, the second mapping relationship may be established through the following process:

[0081] In the first step, the output of desalted water flowing through the first electric valve is calibrated at different openings of the first electric valve to obtain a plurality of two-dimensional calibration points.

[0082] It can be understood that since the opening of the first electric valve can control the flow of desalted water and thus the output of the desalted water, there must be a certain corresponding relationship between the opening of the first electric valve and the output of the desalted water. For this reason, this embodiment obtains the output of the desalted water at different openings of the first electric valve through calibration, and thus multiple two-dimensional calibration points can be obtained.

[0083] In the second step, a plurality of target calibration points are extracted from the plurality of two-dimensional calibration points, where the opening of the first electric valve is within a preset safe opening range.

[0084] In this embodiment, taking into account the application scenarios and safety requirements, the opening of the first electric valve is not infinitely adjustable, but has a safe opening range. During the control process, it is necessary to ensure that the opening of the first electric valve is within the safe opening range to ensure the safety of the regulation process.

[0085] To this end, this embodiment extracts high-quality data points that meet a preset safety opening range from a plurality of two-dimensional calibration points, thereby obtaining a plurality of target calibration points.

[0086] The third step is to perform fitting processing on multiple target calibration points to obtain a second mapping relationship.

[0087] In some embodiments, before fitting the multiple target calibration points, preprocessing operations such as error point elimination and data completion may be performed on the multiple target calibration points to ensure the accuracy of the second mapping relationship obtained by subsequent fitting.

[0088] In one embodiment, see Figure 2 A second electric valve K2 is provided on the pipeline from the heat network drain to the condensate system. The above method may further include:

[0089] The temperature deviation value is compared with a preset first deviation threshold value. When the temperature deviation value is continuously higher than the first deviation threshold value for a preset period of time, the opening of the second electric valve K2 is controlled to be reduced to a first safety opening degree.

[0090] In this embodiment, the second electric valve K2 is mainly used to control the drainage flow rate input into the condensate system.

[0091] It can be understood that if the temperature deviation value continues to be higher than the first deviation threshold preset time, it means that the actual measured temperature of the heating network drain continues to be high. At this time, there is a major safety hazard in the condensate water system. In order to ensure the safe operation of the condensate water system, the opening of the second electric valve can be reduced to reduce the heating network drain flow entering the condensate water system.

[0092] In actual applications, the first deviation threshold can be set with multiple sub-thresholds, such as setting multiple sub-thresholds with equal numerical intervals. Correspondingly, the first safety opening can also be set with multiple safety sub-opening values, and each sub-threshold is set with a corresponding safety sub-opening value, thereby realizing multi-level regulation of the opening of the second electric valve.

[0093] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control method may also include:

[0094] The temperature deviation value is compared with a preset second deviation threshold value. When the temperature deviation value continues to be higher than the second deviation threshold value for a preset period of time, a temperature abnormality warning message is generated and issued.

[0095] In this embodiment, the second deviation threshold is higher than the first deviation threshold. If the temperature deviation value continues to be higher than the second deviation threshold for a preset period of time, it means that the actual measured temperature of the heat network drain is continuously at the upper critical value, and it is difficult to achieve the purpose of lowering the drain temperature by automatically adjusting the valve opening in a short time. At this time, there is a great safety hazard in the entire combined cycle heating unit, and human intervention and control are urgently needed. Therefore, this embodiment promptly reports the abnormal situation by sending temperature abnormality warning information to the staff, so that the staff can intervene in the control process in time.

[0096] In actual applications, temperature abnormality warning information includes key information such as the actual measured value of the heat network drain temperature within a preset time period, temperature deviation value, and unit identification information.

[0097] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control method may also include:

[0098] In the first step, the first pressure value of the heat network drain water and the second pressure value of the desalted water are respectively obtained.

[0099] The second step is to compare the first pressure value with the second pressure value to obtain a comparison result.

[0100] In the third step, when the comparison result shows that the first pressure value is higher than the second pressure value, a pressure abnormality warning message is generated and issued.

[0101] It can be understood that in order to ensure that the desalted water of the desalted water system can pass through the first electric valve to cool the hot network drain, in actual applications, it is necessary to ensure that the pressure of the desalted water is higher than the pressure of the hot network drain, that is, the second pressure value should be higher than the first pressure value. When the above pressure relationship is not met, this embodiment can issue a pressure abnormality warning message to relevant staff to remind relevant staff to intervene and control in time to ensure that the temperature of the hot network drain can be effectively controlled.

[0102] In some embodiments, see Figure 2 A manual valve K3 may also be provided on the connecting pipe between the desalted water system and the condensate water system. The manual valve K3 is provided in front of the first electric valve K1, so that the staff can control the amount of desalted water through the manual valve K3 during manual intervention and regulation.

[0103] In some embodiments, see Figure 2 A check valve K4 may also be provided on the connecting pipe between the desalted water system and the condensate water system. The check valve K4 is provided on the rear side of the first electric valve K1. The setting of the check valve K4 may control the unidirectional flow of water and prevent the hot network drainage from entering the desalted water system.

[0104] like Figure 2As shown, the heat network drain passes through the second electric valve K2 and enters the front of the deironing filter in the condensate system. A condensate pump and a shaft seal heater are also provided on one side of the deironing filter. After passing through the shaft seal heater, a part of the condensate is recycled into the exhaust device through the condensate pump, and the other part is sent to the waste heat boiler. The other side of the deironing filter is also connected to the pre-pump, and the pre-pump is connected to the exhaust device. The output of the pre-pump can also enter the exhaust device through the pre-pump recycling loop. The gas discharged from the low-pressure cylinder at the top of the exhaust device will enter the air-cooling island, and the air-cooled condensate output by the air-cooling island enters the exhaust device.

[0105] The method for controlling the drain water temperature of the heating network of the combined cycle heating unit provided in the embodiment of the present invention can realize the closed-loop control of the drain water temperature of the heating network with high control accuracy, thereby improving the operation safety of the entire combined cycle heating unit.

[0106] Based on the same general inventive concept, the present invention also protects a combined cycle heating unit heat network drain temperature control system. The combined cycle heating unit heat network drain temperature control system provided by the present invention is described below. The combined cycle heating unit heat network drain temperature control system described below and the combined cycle heating unit heat network drain temperature control method described above can be referenced to each other.

[0107] Figure 3 It is a structural schematic diagram of a heat network drain temperature control system for a combined cycle heating unit provided in an embodiment of the present invention.

[0108] like Figure 3 As shown, the combined cycle heating unit heat network drain temperature control system provided by the embodiment of the present invention can be applied to a combined cycle heating unit including a desalted water system and a condensate water system. The control system specifically includes:

[0109] The temperature measuring element 210 is arranged near the pipe inlet of the condensate system;

[0110] The first electric valve 220 is provided on the connecting pipe between the desalted water system and the condensate water system;

[0111] The control device 230 is connected to the temperature measuring element 210 and the first electric valve 220 respectively, and the control device 230 is used for:

[0112] Obtain the actual measured temperature of the hot network drain that is about to enter the condensate water system, which is collected by the temperature measuring element 210; calculate the temperature deviation value between the actual measured temperature of the hot network drain and the preset hot network drain safety temperature; determine the demand for desalted water for cooling based on the temperature deviation value and a preset first mapping relationship; wherein the first mapping relationship is used to characterize the correspondence between the demand for desalted water and the temperature deviation value; determine the target opening of the first electric valve based on the demand for desalted water and a preset second mapping relationship; wherein the second mapping relationship is used to characterize the correspondence between the opening of the first electric valve and the demand for desalted water; and control the action of the first electric valve 220 according to the target opening.

[0113] In one embodiment, the first mapping relationship may be established through the following process:

[0114] Obtain the historical temperature sequence of the heat network drain in the combined cycle heating unit;

[0115] According to the heat network drain safety temperature, determine the lower limit and upper limit of the safety temperature, and establish a safety temperature range;

[0116] Extract the temperature subsequence that meets the safe temperature range in the historical temperature sequence;

[0117] Obtain the amount of deionized water used at each temperature sampling point in the temperature subsequence at the corresponding sampling time;

[0118] Establish multiple two-dimensional data points according to each temperature sampling point in the temperature subsequence and the desalted water usage corresponding to each temperature sampling point;

[0119] A fitting process is performed on a plurality of two-dimensional data points to obtain a first mapping relationship.

[0120] In one embodiment, the second mapping relationship may be established through the following process:

[0121] Under different opening degrees of the first electric valve, the output of the deionized water flowing through the first electric valve is calibrated to obtain a plurality of two-dimensional calibration points;

[0122] Extracting a plurality of target calibration points where the opening of the first electric valve is within a preset safe opening range from the plurality of two-dimensional calibration points;

[0123] A fitting process is performed on the plurality of target calibration points to obtain a second mapping relationship.

[0124] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control method may also include:

[0125] The temperature deviation value is compared with a preset second deviation threshold value. When the temperature deviation value continues to be higher than the second deviation threshold value for a preset period of time, a temperature abnormality warning message is generated and issued.

[0126] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control method may also include:

[0127] Respectively obtain a first pressure value of the heat network drain and a second pressure value of the desalted water;

[0128] Comparing the first pressure value with the second pressure value to obtain a comparison result;

[0129] When the comparison result is that the first pressure value is higher than the second pressure value, a pressure abnormality warning message is generated and issued.

[0130] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control system may also include:

[0131] The second electric valve is arranged on the pipeline from the heat network drain to the condensate system, and the second electric valve is connected to the control device;

[0132] The control device can also be used to:

[0133] The temperature deviation value is compared with a preset first deviation threshold value. When the temperature deviation value is continuously higher than the first deviation threshold value for a preset period of time, the opening of the second electric valve is controlled to be reduced to a first safety opening degree.

[0134] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control system may also include:

[0135] The check valve is arranged on the connecting pipe between the desalted water system and the condensate water system and is located at the rear side of the first electric valve.

[0136] In one embodiment, the above-mentioned combined cycle heating unit heat network drain water temperature control system may also include:

[0137] The manual valve is arranged on the connecting pipe between the desalted water system and the condensate water system and is located in front of the first electric valve.

[0138] It should be noted that in the combined cycle heating unit heat network drain temperature control system provided in this embodiment, the specific setting positions of each valve can be found in Figure 2 shown.

[0139] Figure 4 Schematic diagram of the structure of the control device in the embodiment of the present invention.

[0140] like Figure 4As shown, the control device may include: a processor 310, a communication interface 320, a memory 330 and a communication bus 340, wherein the processor 310, the communication interface 320 and the memory 330 communicate with each other through the communication bus 340. The processor 310 may call the logic instructions in the memory 330 to execute the combined cycle heating unit heat network drain temperature control method provided in the above embodiments.

[0141] In addition, the logic instructions in the above-mentioned memory 330 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0142] To sum up, the combined cycle heating unit heat network drain temperature control system provided by the embodiment of the present invention solves the problem of low operating safety of the condensate system caused by the uncontrollable drain temperature during the heating process of the combined cycle heating unit, realizes precise control of the drain temperature, and thus improves the operating safety of the entire combined cycle heating unit.

[0143] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the combined cycle heating unit heat network drain temperature control method provided in the above embodiments.

[0144] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for controlling the temperature of the heat network drain of a combined cycle heating unit provided in the above-mentioned embodiments.

[0145] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0146] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined cycle heating unit heat network drain water temperature control method, characterized in that: Applicable to a combined cycle heating unit including a desalted water system and a condensate water system, a first electric valve is provided on a connecting pipe between the desalted water system and the condensate water system, and a temperature measuring element is provided near the pipe inlet of the condensate water system; the method comprises: Obtaining the actual measured temperature of the heat network drain water about to enter the condensate water system collected by the temperature measuring element; Calculating the temperature deviation between the actual temperature of the heating network drain and the preset heating network drain safety temperature; Based on the temperature deviation value and a preset first mapping relationship, determining the amount of desalted water required for cooling; wherein the first mapping relationship is used to characterize the corresponding relationship between the amount of desalted water required and the temperature deviation value; Based on the desalted water demand and a preset second mapping relationship, determining a target opening of the first electric valve; wherein the second mapping relationship is used to characterize a corresponding relationship between the opening of the first electric valve and the desalted water demand; The first electric valve is controlled to operate according to the target opening.

2. The method for controlling the temperature of the heat network drain of a combined cycle heating unit according to claim 1, characterized in that: The first mapping relationship is established through the following process: Obtain the historical temperature sequence of the heat network drain in the combined cycle heating unit; According to the heat network drain safety temperature, determine the safety temperature lower limit value and the safety temperature upper limit value respectively, and establish a safety temperature range; Extracting a temperature subsequence that satisfies the safety temperature range from the historical temperature sequence; Obtaining the amount of deionized water used at each temperature sampling point in the temperature subsequence at the corresponding sampling time; Establishing a plurality of two-dimensional data points according to each temperature sampling point in the temperature subsequence and the desalted water usage corresponding to each of the temperature sampling points; Fitting processing is performed on the multiple two-dimensional data points to obtain the first mapping relationship.

3. The method for controlling the temperature of the heat network drain of a combined cycle heating unit according to claim 1, characterized in that: The second mapping relationship is established through the following process: Under different opening degrees of the first electric valve, calibrate the output of deionized water flowing through the first electric valve to obtain a plurality of two-dimensional calibration points; Extracting a plurality of target calibration points where the opening of the first electric valve is within a preset safe opening range from the plurality of two-dimensional calibration points; Fitting is performed on the multiple target calibration points to obtain the second mapping relationship.

4. The method for controlling the temperature of the heat network drain of a combined cycle heating unit according to claim 1, characterized in that: A second electric valve is provided on the pipeline from the heat network drain to the condensate system, and the method further comprises: The temperature deviation value is compared with a preset first deviation threshold value, and when the temperature deviation value is continuously higher than the first deviation threshold value for a preset time period, the opening of the second electric valve is controlled to be reduced to a first safety opening degree.

5. The method for controlling the drain water temperature of a combined cycle heating unit according to any one of claims 1 to 4, characterized in that: The method further comprises: The temperature deviation value is compared with a preset second deviation threshold value, and when the temperature deviation value is continuously higher than the second deviation threshold value for a preset period of time, a temperature abnormality warning message is generated and issued.

6. The method for controlling the drain water temperature of a combined cycle heating unit according to any one of claims 1 to 4, characterized in that: The method further comprises: Respectively obtain a first pressure value of the heat network drain and a second pressure value of the desalted water; Comparing the first pressure value with the second pressure value to obtain a comparison result; When the comparison result is that the first pressure value is higher than the second pressure value, a pressure abnormality warning message is generated and issued.

7. A combined cycle heating unit heat network drain temperature control system, characterized in that: Applicable to a combined cycle heating unit including a desalted water system and a condensate water system, the control system includes: A temperature measuring element is arranged near the pipe inlet of the condensate water system; A first electric valve is provided on a connecting pipe between the desalted water system and the condensate water system; A control device is connected to the temperature measuring element and the first electric valve respectively, and the control device is used to: Obtain the actual measured temperature of the hot network drain that is about to enter the condensate water system collected by the temperature measuring element; calculate the temperature deviation value between the actual measured temperature of the hot network drain and the preset hot network drain safety temperature; determine the demand for desalted water for cooling based on the temperature deviation value and a preset first mapping relationship; wherein the first mapping relationship is used to characterize the correspondence between the demand for desalted water and the temperature deviation value; determine the target opening of the first electric valve based on the demand for desalted water and a preset second mapping relationship; wherein the second mapping relationship is used to characterize the correspondence between the opening of the first electric valve and the demand for desalted water; and control the action of the first electric valve according to the target opening.

8. The combined cycle heating unit heat network drain temperature control system according to claim 7, characterized in that: The system further comprises: A second electric valve is arranged on a pipeline from the heat network drain to the condensate system, and the second electric valve is connected to the control device; The control device is also used for: The temperature deviation value is compared with a preset first deviation threshold value, and when the temperature deviation value is continuously higher than the first deviation threshold value for a preset time period, the opening of the second electric valve is controlled to be reduced to a first safety opening degree.

9. The combined cycle heating unit heat network drain temperature control system according to claim 7, characterized in that: The system further comprises: The check valve is arranged on the connecting pipe between the desalted water system and the condensate water system and is located at the rear side of the first electric valve.

10. The combined cycle heating unit heat network drain water temperature control system according to claim 7, characterized in that: The system further comprises: The manual valve is arranged on the connecting pipe between the desalted water system and the condensate water system and is located in front of the first electric valve.

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