Control system and method for shell and tube heat exchanger

Abstract

The invention discloses a shell and tube heat exchanger control system and method.The control system comprises a switching system and a descaling system.The switching system is used for calculating the flow speed according to the flow of a water inlet of a shell and tube heat exchanger and generating a process switching instruction according to the size relation between the flow speed and a preset recommended flow speed range; the flow number of the shell-tube heat exchanger is switched or a flow velocity prompt is given out; the descaling system is used for calculating the heat exchange amount according to the temperatures of the water inlet and the water outlet of the shell-and-tube heat exchanger and generating a current heat exchange curve in combination with the water temperature of the water inlet, and when the current heat exchange curve is lower than a same-flow standard heat exchange curve of a set proportion, if a descaling mode is selected, reverse cleaning is conducted or a cleaning prompt is sent out. The flow speed and flow are controlled through the switching flow number of the switching system, the heat exchange performance and the heat exchange efficiency are improved, the dirt accumulation amount in the shell-and-tube heat exchanger is judged through the heat exchange curve of the descaling system, and automatic descaling is conducted through reverse cleaning.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchangers, and in particular relates to a control system and method for a shell and tube heat exchanger. Background Art

[0002] Shell-and-tube heat exchangers are a key component of chillers. Most current chillers utilize shell-and-tube evaporators to exchange heat between the refrigerant and the coolant, thereby meeting user requirements for indoor temperatures in different seasons. During chiller operation, when the flow rate within the shell-and-tube heat exchange tubes is low, impurities within the water system will rapidly deposit on the tube surfaces. This increases thermal resistance, reduces heat transfer efficiency, and increases the risk of icing at low temperatures. Higher flow rates within the tubes also result in greater pressure loss on the water side, increasing pump power consumption. Excessively high flow rates can accelerate equipment wear and even cause failures.

[0003] At the same time, the water temperature and water flow during the operation of the chiller may be affected by the ambient temperature, the operation of the water pump and the insufficient supply of cold water, resulting in the water supply condition being different from the design condition, making the heat exchange effect of the shell and tube heat exchanger unsatisfactory. The number of processes of the shell and tube heat exchanger in the existing chiller is fixed, and the number of processes cannot be adjusted according to the water supply condition. In addition, the accumulation of dirt in the shell and tube heat exchanger in the existing chiller will lead to a decrease in the heat exchange effect, but it cannot be automatically descaled. It is usually cleaned by disassembling the shell and tube heat exchanger, which has low cleaning efficiency and is inconvenient to use. Summary of the Invention

[0004] In order to solve the problem that the existing technology cannot adapt to water supply conditions with different water temperatures and flow rates and achieve the best heat exchange effect, the present invention provides a control system and method for a shell and tube heat exchanger.

[0005] The present invention adopts the following technical solutions.

[0006] A first aspect of the present invention discloses a control system for a shell and tube heat exchanger, characterized in that the shell and tube heat exchanger connects a left water chamber and a right water chamber via an array of heat exchange tubes, the heat exchange tubes being divided into a first flow group, a second flow group, a third flow group, and a fourth flow group, and flow ports are provided at the left and right water chambers corresponding to the first and second flow groups, a flow port one on the right water chamber being connected to a water supply pipe, and the remaining flow ports being connected to a return water pipe via a solenoid valve group, and the control system comprising: a switching system and a descaling system;

[0007] The switching system is used to calculate the flow rate based on the water inlet flow rate of the shell and tube heat exchanger, generate a process switching instruction based on the relationship between the flow rate and the preset recommended flow rate range, and then switch the number of processes of the shell and tube heat exchanger or issue a flow rate prompt;

[0008] The descaling system is used to calculate heat exchange capacity according to the temperature of the inlet and outlet of the shell and tube heat exchanger, generate a current heat exchange curve in combination with the water temperature of the inlet, and if the current heat exchange curve is lower than a standard heat exchange curve of the same flow rate with a set proportion, switch the inlet and outlet directions of the right water chamber to perform reverse cleaning or issue a cleaning prompt if the descaling mode is selected.

[0009] Preferably, the switching system comprises a first fixed baffle, a second fixed baffle, a first movable baffle and a second movable baffle.

[0010] The first and third flow groups are separated from the second and fourth flow groups by the first fixed baffle in the left water chamber, and the first flow group and the second flow group are separated by the second fixed baffle in the right water chamber, the first movable baffle is located on the side of the return water pipeline, the second movable baffle is located on the side of the water supply pipeline, and one end of both is screwed with the second fixed baffle, and the other end is moved to a preset stroke position along the inner circumferential wall of the right water chamber according to the flow switching instruction.

[0011] Preferably, the electromagnetic valve group comprises a first, a second and a third electromagnetic valve, the flow passage two on the right water chamber is connected with the return water pipeline through the second electromagnetic valve, the flow passage four on the left water chamber and the flow passage two on the right water chamber are in position correspondence, and the flow passage four is connected to the second electromagnetic valve and the return water pipeline through the first electromagnetic valve, the flow passage three on the left water chamber and the flow passage one on the right water chamber are in position correspondence, and the flow passage three is connected to the first electromagnetic valve and the flow passage four through the third electromagnetic valve.

[0012] Preferably, the flow switching instruction comprises a single flow switching instruction, a double flow switching instruction, a triple flow switching instruction and a quadruple flow switching instruction.

[0013] The single flow switching instruction is to start the first and third electromagnetic valves, and the first and second movable baffles are both moved to a preset top stroke position, so that the water flow flows from the right water chamber to the left water chamber through all the heat exchange tubes, and flows back to the return water pipeline from all the flow passages of the left water chamber.

[0014] The double flow switching instruction is to start the second and third electromagnetic valves, the first movable baffle is moved to a preset top stroke position, the second movable baffle is moved to a preset bottom stroke position, so that the water flow flows from the right water chamber to the left water chamber through the second and fourth flow groups, forming a first flow, the water flow in the left water chamber flows back to the right water chamber from the first and third flow groups through the third electromagnetic valve, forming a second flow, and flows back to the return water pipeline from the flow passage two.

[0015] The three-flow switching instruction is as follows: the first solenoid valve is activated, and the first and second movable baffles are moved to the preset middle stroke positions, so that the water in the right water chamber flows from the second flow group to the left water chamber, forming the first flow, the water in the left water chamber flows from the fourth flow group back to the right water chamber, forming the second flow, and the water in the right water chamber flows from the third flow group back to the left water chamber, forming the third flow, and flows back to the return water pipe from the fourth flow port;

[0016] The four-process switching instructions are: start the second solenoid valve, the first and second movable baffles are moved to the preset middle stroke position, so that the water flow in the right water chamber flows from the second process group to the left water chamber, forming the first process, the water flow in the left water chamber flows back to the right water chamber from the fourth process group, forming the second process, the water flow in the right water chamber flows back to the left water chamber from the third process group, forming the third process, the water flow in the left water chamber flows back to the right water chamber from the first process group, forming the fourth process, and flows back to the return water pipeline from the second flow port.

[0017] Preferably, generating a process switching instruction based on the size relationship between the flow rate and the preset recommended flow rate range, and then switching the number of processes of the shell and tube heat exchanger or issuing a flow rate prompt, includes:

[0018] When the flow rate is greater than the maximum preset recommended flow rate, the current process number of the shell and tube heat exchanger is detected. If the current process number is greater than one, a process switching instruction is generated with the current process number minus one. If the current process number is less than or equal to one, a high flow rate prompt is issued;

[0019] When the flow rate is less than the minimum preset recommended flow rate, the current number of processes of the shell and tube heat exchanger is detected. If the current number of processes is less than four, a process switching instruction is generated with the current number of processes plus one. If the current number of processes is greater than or equal to four, a low flow rate prompt is issued.

[0020] Among them, single process corresponds to process number one, double process corresponds to process number two, triple process corresponds to process number three, and quadruple process corresponds to process number four.

[0021] Preferably, the switching system includes: a flow meter, which is arranged at a position of the circulation port and is used to obtain the water inlet flow.

[0022] Preferably, the descaling system comprises: a three-way valve 1, a three-way valve 2 and a filter, the three-way valve 1 is provided on the water supply pipe, the three-way valve 2 is provided on the return pipe, one path of the three-way valve 1 is provided on the water outlet side of the three-way valve 2 through the filter, and one path of the three-way valve 2 is provided on the water inlet side of the three-way valve 1;

[0023] In the descaling mode, the three-way valve 1 and the three-way valve 2 are started and the shell and tube heat exchanger is switched to the maximum number of processes, so that the water supply pipe supplies water to the flow port 2 on the right water chamber through the three-way valve 2, and the flow port 1 on the right water chamber returns water to the return pipe through the three-way valve 1 and the filter in turn. After the designed time, the descaling mode is exited and the number of descaling times is recorded.

[0024] Preferably, when the descaling times are greater than or equal to a preset times, a cleaning reminder will be issued; when the descaling times are less than a preset times, the descaling times will be reset to zero after the control system is shut down.

[0025] Preferably, the descaling system includes: a temperature sensor, which is arranged at the flow port of the shell and tube heat exchanger and is used to detect the inlet and outlet temperatures.

[0026] A second aspect of the present invention discloses a method for controlling a shell and tube heat exchanger, based on the control system of the shell and tube heat exchanger, comprising the following steps:

[0027] The flow rate is calculated based on the water inlet flow rate of the shell and tube heat exchanger, and a process switching instruction is generated based on the relationship between the flow rate and the preset recommended flow rate range, thereby switching the process number of the shell and tube heat exchanger or issuing a flow prompt;

[0028] The heat exchange amount is calculated based on the water inlet and outlet temperatures and the water inlet flow rate of the shell and tube heat exchanger, and the current heat exchange curve is generated in combination with the water inlet temperature. When the current heat exchange curve is lower than the standard heat exchange curve with the same flow rate at a set ratio, if the descaling mode is selected, the water inlet and outlet directions of the right water chamber will be switched for reverse cleaning or a cleaning prompt will be issued.

[0029] A third aspect of the present invention discloses a chiller, including a control system of the shell and tube heat exchanger.

[0030] A fourth aspect of the present invention discloses an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the control method of the shell and tube heat exchanger when loaded into the processor.

[0031] A fifth aspect of the present invention discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the control method of the shell and tube heat exchanger is implemented.

[0032] The beneficial effect of the present invention is that, compared with the prior art,

[0033] The present invention controls the flow rate by switching the number of flow paths, thereby improving heat exchange performance and efficiency, and enhancing stability and safety. At the same time, the amount of dirt accumulated in the shell and tube heat exchanger is determined by the heat exchange curve. When the heat exchange efficiency is affected, reverse cleaning is performed to automatically remove the dirt, without disassembling the shell and tube heat exchanger, thereby improving cleaning efficiency and convenience.

[0034] The switching system of the application generates flow switching instructions according to the size relationship between the flow rate and the preset recommended flow rate range, and then adjusts the flow rate and flow by switching the flow number of the shell and tube heat exchanger, so that the flow rate is kept within the recommended flow rate range, the heat exchange efficiency and performance are improved, the deposition of impurities caused by too low flow rate and the abrasion and scouring caused by too high flow rate are avoided, the equipment failure rate is reduced, the safety, reliability and durability of operation are improved, the cleaning and maintenance frequency is reduced, the maintenance cost is saved, and when the flow rate cannot be adjusted by switching the flow number, a flow rate prompt will be issued to facilitate timely maintenance of the water chiller.

[0035] The descaling system of the application generates a current heat exchange curve, and when the current heat exchange curve is lower than the same flow standard heat exchange curve with a set proportion, if the descaling mode is selected, the right water chamber inlet and outlet water direction is switched for reverse cleaning. The automatic descaling mode simplifies the cleaning process, reduces the risk of failure caused by dirt, judges the influence of dirt accumulation on the heat exchange performance of the shell and tube heat exchanger through the heat exchange curve, judges the degree of dirt accumulation without disassembling the shell and tube heat exchanger, cleans through the descaling mode, reduces the daily maintenance cost, improves the heat exchange efficiency, maintains the efficient operation of the shell and tube heat exchanger, improves the flow rate by switching to the maximum flow number of the shell and tube heat exchanger to clean the inside of the shell and tube heat exchanger, and makes the water flow in reverse by switching the right water chamber inlet and outlet water direction, so that the dead angle or bending part that cannot be flushed when the water flows in the normal direction can be effectively cleaned to ensure the overall cleaning of the pipeline inside. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is the left and right water chamber side view of the shell and tube heat exchanger of the application;

[0037] Figure 2 is the top view of the shell and tube heat exchanger of the application;

[0038] Figure 3 is the left water chamber cross-sectional view of the application;

[0039] Figure 4 is the right water chamber cross-sectional view of the application;

[0040] Figure 5 is the single flow process schematic diagram of the right water chamber of the application;

[0041] Figure 6 is the double flow process schematic diagram of the right water chamber of the application;

[0042] Figure 7 is the triple flow process schematic diagram of the right water chamber of the application;

[0043] Figure 8 is the quadruple flow process schematic diagram of the right water chamber of the application;

[0044] Figure 9is a structural diagram of the control system of the present application;

[0045] Figure 10 is a descaling mode schematic diagram of the control system of the present application;

[0046] Figure 11 is a flow chart of the switching system of the present application;

[0047] Figure 12 is a flow chart of the descaling system of the present application;

[0048] Figure 13 is a schematic diagram of the heat exchange curve of the present application;

[0049] In the figure: 1, heat exchange pipe; 11, first flow group; 12, second flow group; 13, third flow group; 14, fourth flow group; 2, first fixed baffle; 3, second fixed baffle; 4, first movable baffle; 5, second movable baffle; 6, first strut rod mechanism; 7, second strut rod mechanism; 8, flow-through port. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. The embodiments described in the present application are only a part of the embodiments of the present application, but not all the embodiments. Based on the spirit of the present application, other embodiments obtained by those skilled in the art without making creative efforts fall within the protection scope of the present application.

[0051] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0052] As Figures 1-13 shown, the embodiment 1 of the present application discloses a control system of a shell-and-tube heat exchanger, comprising: a switching system and a descaling system,

[0053] As Figure 1 and Figure 2As shown, a left water chamber and a right water chamber are provided on both sides of the shell and tube heat exchanger, and the left and right water chambers are connected by an array-type heat exchange tube 1. The heat exchange tube 1 is divided into a first process group 11 and a second process group 12 on the upper side and a third process group 13 and a fourth process group 14 on the lower side according to the longitudinal spacing. The heat exchange tube 1 is divided into a first process group 11 and a third process group 13 on the left side and a second process group 12 and a fourth process group 14 on the right side according to the transverse spacing. Flow ports 8 are provided at the upper parts of the left and right water chambers corresponding to the first and second process groups. Flow port 4 is provided at the position of the first process group 11 of the left water chamber and flow port 3 is provided at the position of the second process group 12. Flow port 2 is provided at the position of the first process group 11 of the right water chamber and flow port 1 is provided at the position of the second process group 12. Flow port 1 on the right water chamber is connected to the water supply pipe, and the remaining flow ports are connected to the return pipe through the solenoid valve group.

[0054] The switching system is used to calculate the flow rate based on the water inlet flow rate of the shell and tube heat exchanger, generate a process switching instruction based on the relationship between the flow rate and the preset recommended flow rate range, and then switch the number of processes of the shell and tube heat exchanger or issue a flow rate prompt;

[0055] The switching system includes: a flow meter, which is arranged at a position of the circulation port and is used to obtain the flow rate of the water inlet;

[0056] The flow rate is calculated based on the water inlet flow rate of the shell and tube heat exchanger and is expressed as follows:

[0057] V=q / (M×n×A)

[0058] Where:

[0059] V represents flow velocity;

[0060] q represents the water inlet flow rate;

[0061] n represents the number of processes;

[0062] M represents the number of all heat exchange tubes;

[0063] A represents the cross-sectional area of ​​a single heat exchange tube;

[0064] Preferably, but not limitatively, the present invention calculates the average flow rate through the water inlet flow rate.

[0065] The switching system includes: a first fixed baffle 2, a second fixed baffle 3, a first movable baffle 4 and a second movable baffle 5. The first fixed baffle 2 is used to separate the first and third process groups from the second and fourth process groups in the left water chamber; the second fixed baffle 3 is used to separate the first process group 11 and the second process group 12 in the right water chamber. One end of the second fixed baffle 3 is connected to the inner wall of the right water chamber, and the other end is connected to the middle inner wall of the right water chamber. The first movable baffle 4 is located on the return pipe side, and the second movable baffle 5 is located on the water supply pipe side. One end of both is screwed to the second fixed baffle 3, and the other end moves to the preset stroke position along the inner wall of the right water chamber according to the process switching instruction.

[0066] The switching system also includes: a first strut mechanism 6 and a second strut mechanism 7. The first strut mechanism 6 is connected to the first movable baffle 4, and the second strut mechanism 7 is connected to the second movable baffle 5. The strut mechanism has a built-in motor, and the motor controls the extension and retraction of the strut mechanism to move the movable baffle to a preset stroke position.

[0067] Preferably, but not limitatively, the support rod mechanism may adopt a ball screw structure or a connecting rod structure to control the telescopic movement of the support rod mechanism.

[0068] like Figure 9 As shown, the solenoid valve group includes: a first, a second and a third solenoid valve, the flow port 2 on the right water chamber is connected to the return pipe through the second solenoid valve, the flow port 4 on the left water chamber and the flow port 2 on the right water chamber correspond in position and are connected between the second solenoid valve and the return pipe through the first solenoid valve, the flow port 3 on the left water chamber and the flow port 1 on the right water chamber correspond in position and are connected between the first solenoid valve and the flow port 4 through the third solenoid valve.

[0069] like Figure 5-Figure 9 As shown, the process switching instruction includes: a single process switching instruction, a dual process switching instruction, a triple process switching instruction and a quad process switching instruction;

[0070] The single-flow switching instruction is as follows: the first and third solenoid valves are activated, the first and second movable baffles are moved to the preset top stroke positions, water enters the first flow port, and the water flows from the right water chamber through all heat exchange tubes 1 to the left water chamber, and then flows back to the return water pipe from all flow ports of the left water chamber;

[0071] The dual-flow switching instruction is as follows: the second and third solenoid valves are activated, the first movable baffle 4 moves to the preset top stroke position, the second movable baffle 5 moves to the preset bottom stroke position, water enters the first flow port, and the water flows from the right water chamber through the second and fourth flow groups to the left water chamber, forming the first flow. The water in the left water chamber flows back to the right water chamber through the first and third flow groups via the third solenoid valve, forming the second flow, and flows back to the return water pipeline from the second flow port.

[0072] The three-flow switching instruction is as follows: the first solenoid valve is activated, the first and second movable baffles are moved to the preset middle stroke position, water enters the first flow port, and the water in the right water chamber flows from the second flow group to the left water chamber, forming the first flow; the water in the left water chamber flows from the fourth flow group back to the right water chamber, forming the second flow; the water in the right water chamber flows from the third flow group back to the left water chamber, forming the third flow, and flows back to the return water pipe from the fourth flow port;

[0073] The four-process switching instructions are: start the second solenoid valve, the first and second movable baffles are moved to the preset middle stroke position, water enters the flow port one, so that the water flow in the right water chamber flows from the second flow group to the left water chamber, forming the first flow, the water flow in the left water chamber flows back to the right water chamber from the fourth flow group, forming the second flow, the water flow in the right water chamber flows back to the left water chamber from the third flow group, forming the third flow, the water flow in the left water chamber flows back to the right water chamber from the first flow group, forming the fourth flow, and flows back to the return water pipeline from the flow port two.

[0074] The generating of the process switching instruction according to the relationship between the flow rate and the preset recommended flow rate range includes:

[0075] When the flow rate is greater than the maximum preset recommended flow rate, the current process number of the shell and tube heat exchanger is detected. If the current process number is greater than one, a process switching instruction is generated with the current process number minus one. If the current process number is less than or equal to one, a high flow rate prompt is issued;

[0076] When the flow rate is less than the minimum preset recommended flow rate, the current number of processes of the shell and tube heat exchanger is detected. If the current number of processes is less than four, a process switching instruction is generated with the current number of processes plus one. If the current number of processes is greater than or equal to four, a low flow rate prompt is issued.

[0077] Among them, single process corresponds to process number one, double process corresponds to process number two, triple process corresponds to process number three, and quadruple process corresponds to process number four.

[0078] like Figure 11 To more clearly illustrate the outstanding essential features of the present invention and the significant advancements it brings to the prior art, an application example of the present invention is described below. The steps include:

[0079] Start the control system and make the shell and tube heat exchanger run according to the designed flow number. Obtain the water inlet flow q and calculate the flow velocity V. Compare the flow velocity V with the preset recommended flow velocity range [Vmin, Vmax].

[0080] When the flow rate V>Vmax, the current process number n of the shell and tube heat exchanger is detected. If n>1, a process switching instruction of n-1 is generated. If n≤1, the process number n cannot be reduced and a high flow rate prompt will be issued;

[0081] When the flow rate V is less than Vmin, the current process number n of the shell and tube heat exchanger will be detected. If n is less than 4, a process switching instruction of n+1 will be generated. If n is greater than or equal to 4, the process number cannot be increased and a low flow rate prompt will be issued.

[0082] The descaling system is used to calculate the heat exchange rate based on the inlet and outlet temperatures and the inlet flow rate of the shell and tube heat exchanger, and generate a current heat exchange curve in combination with the inlet water temperature. When a data point on the current heat exchange curve is lower than a data point of a standard heat exchange curve with the same flow rate of a set proportion, a prompt will be given to determine whether to enter the descaling mode. If the descaling mode is selected, the inlet and outlet directions of the right water chamber will be switched for reverse cleaning or a cleaning prompt will be issued.

[0083] It can be understood that the standard heat exchange curve is obtained through the shell and tube heat exchanger and the refrigerant parameters. At the same time, the set ratio is less than 1. Considering the safety margin setting, preferably but not restrictively, the set ratio can be set to 0.7.

[0084] The descaling system includes a temperature sensor, which is arranged at the circulation port 8 and is used to detect the inlet and outlet temperatures.

[0085] The heat exchange rate is calculated based on the water inlet and outlet temperatures and the water inlet flow rate of the shell and tube heat exchanger and is expressed as follows:

[0086] Q=q×ρ×C×ΔT

[0087] Where:

[0088] Q represents the heat transfer amount;

[0089] q represents the water inlet flow rate;

[0090] ρ represents the density of the coolant;

[0091] C represents the specific heat capacity of the coolant;

[0092] ΔT represents the inlet and outlet temperature difference obtained based on the inlet and outlet temperatures;

[0093] The descaling system includes: a three-way valve 1, a three-way valve 2 and a filter. The three-way valve 1 is provided on the water supply pipe, and the three-way valve 2 is provided on the return pipe. One path of the three-way valve 1 is provided on the outlet side of the three-way valve 2 through the filter, and one path of the three-way valve 2 is provided on the inlet side of the three-way valve 1.

[0094] In the descaling mode, the three-way valve 1 and the three-way valve 2 are started and the shell and tube heat exchanger is switched to the maximum number of processes, so that the water supply pipe supplies water to the flow port 2 through the three-way valve 2, and the flow port 1 returns water to the return pipe through the three-way valve 1 and the filter in turn, switching the inlet and outlet directions of the right water chamber. After the designed time, the descaling mode is exited, the three-way valve 1, the three-way valve 2 and the shell and tube heat exchanger are restored to their original working states, and the number of descaling times is recorded; at the same time, the dirt reversely flushed in the descaling mode will be collected by the filter, and the dirt will be removed by regularly replacing the filter element.

[0095] When the descaling times are greater than or equal to the preset times, a cleaning reminder will be issued, and the descaling times will not be reset after the control system is shut down. When the descaling times are less than the preset times, the descaling times will be reset after the control system is shut down.

[0096] Preferably, but not limitatively, the preset number may be three.

[0097] like Figure 12 To more clearly illustrate the outstanding essential features of the present invention and the significant advancements it brings to the prior art, an application example of the present invention is described below. The steps include:

[0098] Start the control system, detect the inlet and outlet temperatures and inlet flow of the shell and tube heat exchanger, calculate the heat exchange according to the inlet and outlet temperatures and inlet flow, combine the heat exchange and inlet temperature to generate the current heat exchange curve, compare the current heat exchange curve with the standard heat exchange curve of the same flow, if the data point on the current heat exchange curve is lower than 0.7 times the standard heat exchange curve of the same flow, it will prompt whether to enter the descaling mode, if you choose to enter the descaling mode, three-way valve 1 and three-way valve 2 are started and the shell and tube heat exchanger is switched to the maximum number of processes, so that the water supply pipe passes The three-way valve 2 supplies water to the flow port 2, and the flow port 1 returns water to the return pipe through the three-way valve 1 and the filter in turn. The inlet and outlet directions of the right water chamber are switched for reverse flushing. After the designed time, the descaling mode is exited, and the three-way valve 1, the three-way valve 2 and the shell and tube heat exchanger are restored to their original working conditions, and the descaling times N are recorded; when N ≥ 3, a cleaning reminder will be issued, and when N < 3, the original state will be maintained for normal operation. After the control system is shut down, when N < 3, the descaling times N will be reset to zero. When N ≥ 3, the descaling times N remains unchanged, and the cleaning reminder is retained.

[0099] Embodiment 2 of the present invention discloses a method for controlling a shell and tube heat exchanger, comprising the following steps:

[0100] The flow rate is calculated based on the water inlet flow rate of the shell and tube heat exchanger, and a process switching instruction is generated based on the relationship between the flow rate and the preset recommended flow rate range, thereby switching the process number of the shell and tube heat exchanger or issuing a flow prompt;

[0101] The heat exchange amount is calculated based on the water inlet and outlet temperatures and the water inlet flow rate of the shell and tube heat exchanger, and the current heat exchange curve is generated in combination with the water inlet temperature. When the current heat exchange curve is lower than the standard heat exchange curve with the same flow rate at a set ratio, if the descaling mode is selected, the water inlet and outlet directions of the right water chamber will be switched for reverse cleaning or a cleaning prompt will be issued.

[0102] Embodiment 3 of the present invention discloses a chiller, including a control system of the shell and tube heat exchanger.

[0103] Embodiment 4 of the present invention discloses an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded into the processor, the control method of the shell and tube heat exchanger is implemented.

[0104] Embodiment 5 of the present invention discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the control method of the shell and tube heat exchanger is implemented.

[0105] The beneficial effect of the present invention is that, compared with the prior art,

[0106] The present invention controls the flow rate by switching the number of flow paths, thereby improving heat exchange performance and efficiency, and enhancing stability and safety. At the same time, the amount of dirt accumulated in the shell and tube heat exchanger is determined by the heat exchange curve. When the heat exchange efficiency is affected, reverse cleaning is performed to automatically remove the dirt, without disassembling the shell and tube heat exchanger, thereby improving cleaning efficiency and convenience.

[0107] The switching system of the present invention generates a process switching instruction according to the size relationship between the flow rate and the preset recommended flow rate range, and then adjusts the flow rate and flow by switching the process number of the shell and tube heat exchanger, so that the flow rate is kept within the recommended flow rate range, thereby improving the heat exchange efficiency and heat exchange performance, avoiding impurity deposition due to too low flow rate and wear and erosion due to too high flow rate, reducing the equipment failure rate, improving the safety, reliability and durability of operation, reducing the frequency of cleaning and maintenance, saving maintenance costs, and issuing a flow rate prompt when the flow rate cannot be adjusted by switching the process number, so as to facilitate timely maintenance of the chiller.

[0108] The descaling system of the present invention generates a current heat exchange curve. When the current heat exchange curve is lower than the standard heat exchange curve of the same flow rate at a set ratio, if the descaling mode is selected, the inlet and outlet directions of the right water chamber will be switched for reverse cleaning. The automated descaling mode simplifies the cleaning process and reduces the risk of failure caused by dirt. The heat exchange curve is used to judge the impact of dirt accumulation on the heat exchange performance of the shell and tube heat exchanger. The degree of dirt accumulation can be judged without disassembling the shell and tube heat exchanger. Cleaning is performed in descaling mode, which reduces daily maintenance costs, improves heat exchange efficiency, and maintains efficient operation of the shell and tube heat exchanger. By switching to the maximum number of flow processes of the shell and tube heat exchanger and increasing the flow rate, the inside of the shell and tube heat exchanger is flushed and cleaned. By switching the inlet and outlet directions of the right water chamber to make the water flow in reverse, dead corners or bends that cannot be flushed during normal forward flow can be effectively cleaned, ensuring comprehensive cleaning of the inside of the pipeline.

[0109] The present disclosure may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0110] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination thereof. As used herein, a computer-readable storage medium is not to be construed as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through an electrical wire.

[0111] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in the computer-readable storage medium in each computing / processing device.

[0112] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., utilizing an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions. The electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0113] 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 above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A control system for a shell and tube heat exchanger, characterized in that: The shell and tube heat exchanger connects the left water chamber and the right water chamber via an array of heat exchange tubes (1). The heat exchange tubes (1) are divided into a first process group (11), a second process group (12), a third process group (13) and a fourth process group (14). Flow ports (8) are provided at the left and right water chambers corresponding to the first and second process groups. A flow port 1 on the right water chamber is connected to a water supply pipe, and the remaining flow ports are connected to a return water pipe via a solenoid valve group. The control system includes: a switching system and a descaling system. The switching system is used to calculate the flow rate based on the water inlet flow rate of the shell and tube heat exchanger, generate a process switching instruction based on the relationship between the flow rate and the preset recommended flow rate range, and then switch the number of processes of the shell and tube heat exchanger or issue a flow rate prompt; The descaling system is used to calculate the heat exchange rate based on the inlet and outlet temperatures of the shell and tube heat exchanger, and generate a current heat exchange curve based on the water temperature at the inlet. When the current heat exchange curve is lower than the standard heat exchange curve with the same flow rate at a set ratio, if the descaling mode is selected, the inlet and outlet directions of the right water chamber will be switched for reverse cleaning or a cleaning prompt will be issued.

2. The control system of a shell and tube heat exchanger according to claim 1, characterized in that: The switching system comprises: a first fixed baffle (2), a second fixed baffle (3), a first movable baffle (4) and a second movable baffle (5); The first and third process groups are separated from the second and fourth process groups by a first fixed baffle (2) in the left water chamber; the first process group (11) is separated from the second process group (12) by a second fixed baffle (3) in the right water chamber, the first movable baffle (4) is located on the return pipe side, the second movable baffle (5) is located on the water supply pipe side, and one end of both is screwed to the second fixed baffle (3), and the other end moves to a preset stroke position along the inner wall of the right water chamber according to the process switching instruction.

3. The control system of a shell and tube heat exchanger according to claim 2, characterized in that: The solenoid valve group includes: a first, a second and a third solenoid valve, the flow port 2 on the right water chamber is connected to the return pipe through the second solenoid valve, the flow port 4 on the left water chamber and the flow port 2 on the right water chamber correspond in position and the flow port 4 is connected between the second solenoid valve and the return pipe through the first solenoid valve, the flow port 3 on the left water chamber and the flow port 1 on the right water chamber correspond in position and the flow port 3 is connected between the first solenoid valve and the flow port 4 through the third solenoid valve.

4. The control system for a shell and tube heat exchanger according to claim 3, characterized in that: The process switching instructions include: single process switching instructions, dual process switching instructions, triple process switching instructions and quad process switching instructions; The single-flow switching instruction is: start the first and third solenoid valves, and the first and second movable baffles are moved to the preset top stroke position, so that the water flows from the right water chamber through all the heat exchange tubes (1) to the left water chamber, and flows back to the return water pipeline from all the flow ports of the left water chamber; The dual-flow switching instruction is as follows: the second and third solenoid valves are activated, the first movable baffle (4) moves to a preset top stroke position, and the second movable baffle (5) moves to a preset bottom stroke position, so that water flows from the right water chamber through the second and fourth flow groups to the left water chamber, forming a first flow, and the water in the left water chamber flows back to the right water chamber through the first and third flow groups via the third solenoid valve, forming a second flow, and flows back to the return water pipeline from the second flow port; The three-flow switching instruction is as follows: the first solenoid valve is activated, and the first and second movable baffles are moved to the preset middle stroke positions, so that the water in the right water chamber flows from the second flow group to the left water chamber, forming the first flow, the water in the left water chamber flows from the fourth flow group back to the right water chamber, forming the second flow, and the water in the right water chamber flows from the third flow group back to the left water chamber, forming the third flow, and flows back to the return water pipe from the fourth flow port; The four-process switching instructions are: start the second solenoid valve, the first and second movable baffles are moved to the preset middle stroke position, so that the water flow in the right water chamber flows from the second process group to the left water chamber, forming the first process, the water flow in the left water chamber flows back to the right water chamber from the fourth process group, forming the second process, the water flow in the right water chamber flows back to the left water chamber from the third process group, forming the third process, the water flow in the left water chamber flows back to the right water chamber from the first process group, forming the fourth process, and flows back to the return water pipeline from the second flow port.

5. The control system for a shell and tube heat exchanger according to claim 1, characterized in that: The generating of a process switching instruction based on the relationship between the flow rate and the preset recommended flow rate range, thereby switching the number of processes of the shell and tube heat exchanger or issuing a flow rate prompt, includes: When the flow rate is greater than the maximum preset recommended flow rate, the current process number of the shell and tube heat exchanger is detected. If the current process number is greater than one, a process switching instruction is generated with the current process number minus one. If the current process number is less than or equal to one, a high flow rate prompt is issued; When the flow rate is less than the minimum preset recommended flow rate, the current number of processes of the shell and tube heat exchanger is detected. If the current number of processes is less than four, a process switching instruction is generated with the current number of processes plus one. If the current number of processes is greater than or equal to four, a low flow rate prompt is issued. Among them, single process corresponds to process number one, double process corresponds to process number two, triple process corresponds to process number three, and quadruple process corresponds to process number four.

6. The control system for a shell and tube heat exchanger according to claim 1, characterized in that: The switching system includes a flow meter, which is arranged at a position of the circulation port and is used to obtain the flow rate of the water inlet.

7. The control system for a shell and tube heat exchanger according to claim 1, characterized in that: The descaling system includes: a three-way valve 1, a three-way valve 2 and a filter. The three-way valve 1 is provided on the water supply pipe, and the three-way valve 2 is provided on the return pipe. One path of the three-way valve 1 is provided on the outlet side of the three-way valve 2 through the filter, and one path of the three-way valve 2 is provided on the inlet side of the three-way valve 1. In the descaling mode, the three-way valve 1 and the three-way valve 2 are started and the shell and tube heat exchanger is switched to the maximum number of processes, so that the water supply pipe supplies water to the flow port 2 on the right water chamber through the three-way valve 2, and the flow port 1 on the right water chamber returns water to the return pipe through the three-way valve 1 and the filter in turn. After the designed time, the descaling mode is exited and the number of descaling times is recorded.

8. The control system for a shell and tube heat exchanger according to claim 7, characterized in that: When the descaling times are greater than or equal to the preset times, a cleaning reminder will be issued. When the descaling times are less than the preset times, the descaling times will be reset to zero after the control system is shut down.

9. The control system for a shell and tube heat exchanger according to claim 1, characterized in that: The descaling system comprises a temperature sensor, which is arranged at a flow port (8) of the shell and tube heat exchanger and is used to detect the inlet and outlet temperatures.

10. A method for controlling a shell and tube heat exchanger, based on the control system of the shell and tube heat exchanger according to any one of claims 1 to 9, characterized in that: The flow rate is calculated based on the water inlet flow rate of the shell and tube heat exchanger, and a process switching instruction is generated based on the relationship between the flow rate and the preset recommended flow rate range, thereby switching the process number of the shell and tube heat exchanger or issuing a flow prompt; The heat exchange amount is calculated based on the water inlet and outlet temperatures and the water inlet flow rate of the shell and tube heat exchanger, and the current heat exchange curve is generated in combination with the water inlet temperature. When the current heat exchange curve is lower than the standard heat exchange curve with the same flow rate at a set ratio, if the descaling mode is selected, the water inlet and outlet directions of the right water chamber will be switched for reverse cleaning or a cleaning prompt will be issued.

11. A chiller, characterized in that: A control system comprising the shell and tube heat exchanger according to any one of claims 1 to 9.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the computer program is loaded into a processor, the method for controlling a shell and tube heat exchanger according to claim 10 is implemented.

13. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for controlling the shell and tube heat exchanger according to claim 10 is implemented.

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