Condition-adaptive water supply system and its regulation method

Abstract

This invention relates to the field of water supply technology, and provides an adaptive water supply system and its control method, including an inlet pipe, a jet pump, a feed water pump, a return pipe, a return regulating valve, a feed water regulating valve, and an outlet pipe; wherein, the first inlet of the jet pump is connected to the inlet pipe, the second inlet is connected to one end of the return pipe, and the outlet is connected to the inlet of the feed water pump; the outlet of the feed water pump is connected to the outlet pipe, and the other end of the return pipe is connected to the outlet pipe; the feed water regulating valve is installed on the outlet pipe, and the water flow rate on the outlet pipe is controlled by adjusting the opening of the feed water regulating valve; the return regulating valve is installed on the return pipe, and the start and stop of the jet pump and the water pressure flowing from the jet pump to the feed water pump are controlled by adjusting the opening of the return regulating valve, so as to meet the water demand and head demand under different operating conditions, thereby improving the matching degree between the water supply system and the variable operating conditions of the boiler system.

Description

Technical Field

[0001] This invention relates to the field of water supply technology, and in particular to an adaptive water supply system and its control method. Background Technology

[0002] The function of the feedwater system is to pressurize the condensate, thereby raising the condensate pressure from a low pressure to the higher pressure level required at the boiler inlet. A stable feedwater supply is essential for ensuring the continuous steam generation of the boiler system. Whether in thermal power plants or marine boiler systems, the feedwater system is one of the key systems. The core pressurizing equipment in traditional feedwater systems is the feedwater pump, which is typically a centrifugal pump. However, during boiler system changes, especially in marine boilers, the required feedwater flow rate changes significantly, while the required head remains relatively constant. This characteristic of demand variation is poorly matched with the characteristics of the feedwater pump. To adapt to the changing boiler operating conditions, the feedwater pump usually needs to operate at variable speeds to accommodate these changes. Therefore, variable frequency pumps are required, increasing the cost and space requirements due to the added frequency converter equipment. Furthermore, even with variable frequency operation, the feedwater pump's operating point deviates from its highest efficiency condition, resulting in poor equipment performance, reduced operating efficiency, and increased noise levels.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0004] This invention provides an adaptive feedwater system and its control method to solve the problem of poor matching between the operating characteristics of existing feedwater systems and the changing operating conditions of boiler systems.

[0005] This invention provides an adaptive water supply system, including an inlet pipe, a jet pump, a feed pump, a return pipe, a return regulating valve, a feed regulating valve, and an outlet pipe;

[0006] The jet pump and the water supply pump are connected in series between the inlet pipe and the outlet pipe. The first inlet of the jet pump is connected to the inlet pipe, the second inlet of the jet pump is connected to one end of the return pipe, the outlet of the jet pump is connected to the inlet of the water supply pump, the outlet of the water supply pump is connected to the outlet pipe, and the other end of the return pipe is connected to the outlet pipe.

[0007] The water supply regulating valve is installed on the outlet pipe. The water flow rate on the outlet pipe is controlled by adjusting the opening degree of the water supply regulating valve. The return regulating valve is installed on the return pipe. The start and stop of the jet pump and the water pressure flowing from the jet pump to the water supply pump are controlled by adjusting the opening degree of the return regulating valve.

[0008] According to the adaptive water supply system provided by the present invention, under the first operating condition, the water supply flow rate of the water supply system is the maximum flow rate, the water supply flow rate of the water supply pump is the rated flow rate and equal to the water supply flow rate requirement of the first operating condition, the backflow regulating valve is closed, and the jet pump is shut down.

[0009] In the second operating condition, the water supply flow rate of the water supply system is less than the maximum flow rate, the water supply flow rate of the water supply pump is greater than the water supply flow rate requirement of the second operating condition but less than or equal to the rated flow rate, the return regulating valve is opened, and the water output by the water supply pump that is higher than the water supply flow rate requirement of the second operating condition flows through the return pipe to the jet pump to drive the jet pump to start.

[0010] According to the working condition adaptive water supply system provided by the present invention, when the jet pump is turned on, the water in the return pipe and the inlet pipe are mixed and pressurized in the jet pump and then flow to the inlet of the water supply pump. The pressurization value of the jet pump on the water = head requirement value + flow resistance value - head value of the water supply pump.

[0011] The head of the water supply pump is correlated with the rotational speed corresponding to the water flow rate under the corresponding operating conditions in a first mapping relationship, and the pressure boosting value of the jet pump is correlated with the opening degree of the reflux regulating valve in a second mapping relationship. The opening degree of the reflux regulating valve is adjusted according to the difference between the head requirement value and the head of the water supply pump and the second mapping relationship, so that the head of the water supplied to the outlet pipe by the water supply pump is the head requirement value.

[0012] According to the adaptive water supply system provided by the present invention, the head value of the water supply pump under the first operating condition is the sum of the head requirement value and the flow resistance value under the first operating condition, and the head value of the water supply pump under the second operating condition is less than or equal to the head value of the water supply pump under the first operating condition.

[0013] According to the adaptive water supply system provided by the present invention, in the second operating condition, when the head requirement value of the second operating condition is equal to the head requirement value of the first operating condition, the water supply flow rate of the water supply pump is greater than the water supply flow rate requirement of the second operating condition and less than the rated flow rate, and the head value of the water supply pump is less than the sum of the head requirement value of the second operating condition and the flow resistance value.

[0014] According to the adaptive water supply system provided by the present invention, in the second operating condition, when the head requirement value of the second operating condition is greater than the head requirement value of the first operating condition, the water supply flow rate of the water supply pump is equal to the rated flow rate, and the head value of the water supply pump is equal to the head value of the water supply pump in the first operating condition.

[0015] According to the adaptive water supply system provided by the present invention, the water supply flow rate output by the water supply system through the outlet pipe is equal to the water supply flow rate demand for the corresponding operating condition, and the water flow rate output from the outlet pipe is adjusted to the water supply flow rate demand for the corresponding operating condition by adjusting the opening degree of the water supply regulating valve.

[0016] The adaptive water supply system according to the present invention further includes a controller, and both the reflux regulating valve and the water supply regulating valve are electric valves. The jet pump, the water supply pump, the reflux regulating valve, and the water supply regulating valve are all electrically connected to the controller.

[0017] The present invention also provides a control method for an adaptive water supply system as described above, comprising the following steps:

[0018] Step S1: Obtain the water supply flow requirement for the operating condition;

[0019] Step S2: Determine whether the water supply flow demand is the maximum flow of the water supply system. If yes, proceed to step S3; otherwise, proceed to steps S4 and S5.

[0020] Step S3: Adjust the water flow rate of the water supply pump to the rated flow rate, close the backflow regulating valve and the jet pump, and adjust the opening of the water supply regulating valve so that the water flow rate output from the outlet pipe is the required water flow rate. The water flowing into the inlet pipe is transported to the outlet pipe by the water supply pump.

[0021] Step S4: Adjust the water flow rate of the water supply pump to be greater than the required water flow rate and less than or equal to the rated flow rate; adjust the opening of the water supply regulating valve so that the water flow rate output from the outlet pipe is the required water flow rate; adjust the opening of the return regulating valve so that the water output from the water supply pump, which is higher than the required water flow rate, flows through the return pipe to the jet pump, thereby driving the jet pump to start.

[0022] In step S5, the jet pump mixes and pressurizes the water flowing into the return pipe and the inlet pipe, and then delivers it to the outlet pipe via the water supply pump.

[0023] According to the control method of the adaptive water supply system provided by the present invention, the boosting value of the jet pump to water = head demand value + flow resistance value - head value of the water supply pump, wherein the head value of the water supply pump has a first mapping relationship with the rotational speed corresponding to the water supply flow rate under the corresponding operating condition, and the boosting value of the jet pump to water has a second mapping relationship with the opening degree of the return flow regulating valve.

[0024] In step S4, adjusting the opening of the reflux regulating valve includes the following steps:

[0025] Based on the difference between the required head value and the head value of the feed water pump, and the second mapping relationship, the opening of the reflux regulating valve is adjusted so that the head value of the feed water delivered to the outlet pipe by the feed water pump is the required head value.

[0026] The above-described technical solution of the present invention has the following beneficial effects:

[0027] The adaptive feedwater system and its control method of the present invention, by setting an ejector pump, a return pipe, and a return regulating valve on the feedwater system, allows the feedwater pump to be set to its rated flow rate when the feedwater demand (i.e., the boiler system water demand) is at the maximum flow rate of the feedwater system. This rated flow rate is the feedwater pump flow rate corresponding to the maximum flow rate of the feedwater system. At this time, the return regulating valve is closed, and the ejector pump is shut down. Under this condition, the feedwater pump can operate near its highest efficiency point. When the feedwater demand is less than the maximum flow rate of the feedwater system, the feedwater pump can still be operated near its highest efficiency point. However, if the feedwater flow rate is greater than the demand, it will result in a lower feedwater head. This can be addressed by... By adjusting the feedwater regulating valve to maintain the required feedwater flow rate in the outlet pipe, and opening the return regulating valve, water output from the feedwater pump that exceeds the required feedwater flow rate flows through the return pipe to the jet pump, driving the jet pump to start. The water in the return pipe mixes and is pressurized in the jet pump before being delivered to the outlet pipe by the feedwater pump. The pressurization of the water by the jet pump can compensate for the problem of low head caused by high flow rate. Therefore, the adaptive feedwater system and its control method of the present invention can make the feedwater pump operate near the highest efficiency point during the changing operating conditions, improve equipment operating efficiency, reduce equipment noise level, and thus solve the problem of poor matching between the operating characteristics of the existing feedwater system and the changing operating conditions of the boiler system. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the adaptive water supply system provided in an embodiment of the present invention;

[0030] Figure 2 A flowchart illustrating the control method for an adaptive water supply system based on operating conditions, as provided in an embodiment of the present invention.

[0031] Figure label:

[0032] 1. Inlet pipe; 2. Jet pump; 3. Feed pump; 4. Return pipe; 5. Return regulating valve; 6. Feed regulating valve; 7. Outlet pipe. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] Please see Figure 1 The present invention provides an adaptive water supply system for supplying water to a boiler system, comprising an inlet pipe 1, a jet pump 2, a feed water pump 3, a return pipe 4, a return regulating valve 5, a feed water regulating valve 6, and an outlet pipe 7.

[0035] The jet pump 2 and the feed pump 3 are connected in series between the inlet pipe 1 and the outlet pipe 7. The jet pump 2 includes two inlets and one outlet. The first inlet of the jet pump 2 is connected to the inlet pipe 1, the second inlet of the jet pump 2 is connected to one end of the return pipe 4, the outlet of the jet pump 2 is connected to the inlet of the feed pump 3, the outlet of the feed pump 3 is connected to the outlet pipe 7, and the other end of the return pipe 4 is connected to the outlet pipe 7. A feed regulating valve 6 is installed on the outlet pipe 7, and the water flow rate on the outlet pipe 7 is controlled by adjusting the opening of the feed regulating valve 6. A return regulating valve 5 is installed on the return pipe 4, and the water flow rate on the return pipe 4 and the start and stop of the jet pump 2 are controlled by adjusting the opening of the return regulating valve 5. Furthermore, the water pressure flowing from the jet pump 2 to the feed pump 3 is regulated by controlling the start and stop of the jet pump 2.

[0036] It should be noted that the water flowing into the jet pump 2 through the return pipe 4 serves as the driving source for the operation of the jet pump 2. After the jet pump 2 is running, it can pressurize the water flowing into the jet pump 2 through the inlet pipe 1 before it flows out. The specific working principle of the jet pump 2 will not be elaborated here.

[0037] The first operating condition is defined as the condition where the water supply system can provide the boiler system with the maximum flow rate. Under this condition, the water supply flow rate is the maximum flow rate, which corresponds to the design operating condition of the water pump. The rated flow rate of water pump 3 is the water supply flow rate of water pump 3 corresponding to the maximum flow rate of the water supply system. Therefore, under the first operating condition, the water supply flow rate of water pump 3 is set to the rated flow rate and equal to the water supply flow rate requirement of the first operating condition. The head of water pump 3 is the sum of the required head value and the flow resistance value under the first operating condition. At this time, the return flow regulating valve 5 is closed, the jet pump 2 is shut down, and the water in the inlet pipe 1 flows to water pump 3 without being pressurized after passing through jet pump 2. It then flows through water pump 3 and water supply regulating valve 6 to meet the water supply flow rate and head requirements of the first operating condition.

[0038] Specifically, the water supply flow demand is set to m1 under the maximum flow condition of the water supply system (i.e., the first condition), and the head demand is h1. Considering certain pipeline and accessory resistance, the rated flow of water pump 3 is selected as M1 (M1 = m1), and the head of water pump 3 is H1 (H1 = h1 + dh1, where dh1 is the flow resistance value of the pipeline and accessories). Under this condition, the backflow regulating valve 5 is closed, that is, the jet pump 2 does not work.

[0039] The second operating condition is defined as the condition in which the water supply system provides a small flow rate to the boiler system. In the second operating condition, the water supply flow rate of the water supply system is less than the maximum flow rate. At this time, the water supply pump 3 operates at its highest efficiency point, with a speed less than or equal to the rated speed. The water supply flow rate of the water supply pump 3 is greater than the water supply flow rate requirement of the second operating condition but less than or equal to the rated flow rate. The head value of the water supply pump 3 is less than or equal to the head value of the water supply pump 3 in the first operating condition. The return regulating valve 5 is opened, and the water output by the water supply pump 3, which is higher than the water supply flow rate requirement of the second operating condition, flows through the return pipe 4 into the jet pump 2 to drive the jet pump 2 to start.

[0040] When the jet pump 2 is turned on, the water in the return pipe 4 and the inlet pipe 1 are mixed and pressurized in the jet pump 2 and then flow to the inlet of the water supply pump 3. The water then flows through the water supply pump 3 and the water supply regulating valve 6 to supply water to meet the water supply flow rate and head requirements of the second working condition.

[0041] Wherein, the booster pressure of the jet pump on the water = head requirement + flow resistance - head of the feed pump.

[0042] Among them, the head of the water pump 3 has a first mapping relationship with the water flow rate of the water pump 3 under the corresponding operating conditions, and the pressure boost of the jet pump 2 on the water has a second mapping relationship with the opening degree of the return regulating valve 5. For example, the first mapping relationship means that when the water pump is operating at the highest efficiency point of the corresponding speed, the smaller the water flow rate of the water pump 3, the smaller the speed, and the smaller the head; the second mapping relationship means that the larger the opening degree of the return regulating valve 5, the greater the pressure boost of the jet pump 2 on the water.

[0043] Understandably, according to the flow-head characteristic curve of water pump 3, when the pump operating speed decreases, both the flow rate and head at the point of highest efficiency corresponding to the speed of water pump 3 decrease. The water flow rate of the driving source of jet pump 2 also directly affects the pressure boosting value of the water by jet pump 2; the greater the water flow rate of the driving source, the greater the pressure boosting value of the water by jet pump 2.

[0044] Therefore, the opening of the return regulating valve 5 can be adjusted according to the difference between the head requirement value and the head value of the feed water pump and the second mapping relationship, so that the head value of the feed water delivered to the outlet pipe 7 by the feed water pump 3 is the head requirement value.

[0045] In one embodiment, when the head requirement value of the second operating condition is equal to the head requirement value of the first operating condition, the water flow rate of the water pump 3 in the second operating condition is greater than the water flow rate requirement of the second operating condition but less than the rated flow rate, and the head value of the water pump 3 in the second operating condition is less than the sum of the head requirement value of the second operating condition and the flow resistance value.

[0046] Specifically, the feedwater flow requirement is set to m2 (m2 < m1) under a relatively low flow condition (i.e., the second condition) of the feedwater system, and the head requirement is h2 (h2 = h1). If a traditional feedwater system is used, the feedwater pump must operate at a point where the feedwater flow is m2 and the head is h2 + dh2 (dh2 is the flow resistance of the pipeline and accessories). This operating point may deviate significantly from the feedwater pump's design point, leading to reduced pump efficiency, increased noise, poor operating conditions, and affecting the overall performance of the boiler system and the lifespan of the feedwater pump. In this embodiment, the feedwater pump 3 can be operated by frequency converter at a lower speed at its highest efficiency point. The feedwater flow of the feedwater pump 3 is M2 (m2 < M2 < M1), and the head is H2 (H2 < h2 + dh2). Compared to the feedwater requirement of the boiler system, the feedwater flow of the feedwater pump 3 is relatively large, and the head is relatively low. At this time, by adjusting the return regulating valve 5, a flow rate (M2-m2) higher than the required feedwater flow rate is returned through the return pipe 4, driving the jet pump 2 to work and pressurize the feedwater entering from the inlet pipe 1. The pressurization value is (h2+dh2-H2). In this way, the overall output feedwater flow rate of the feedwater system is still m2, and the feedwater head is h2, which meets the needs of the boiler system. Moreover, the feedwater pump 3 is operating near its highest efficiency, and the power consumption is lower than the above-mentioned biased operating condition (feedwater pump 3 flow rate m2, head h2+dh2). The equipment is operating well.

[0047] In another embodiment, when the head requirement value of the second operating condition is greater than the head requirement value of the first operating condition, the water supply flow rate of the water pump 3 in the second operating condition is equal to the rated flow rate, and the head value of the water pump 3 in the second operating condition is equal to the head value of the water pump 3 in the first operating condition.

[0048] Specifically, the water flow demand under another, smaller flow condition in the water supply system is set to m3 (m3 < m1), and the head demand is h3 (h3 > h1). Traditional water supply systems still suffer from the problem of the water pump operating conditions deviating significantly from the design point. In this embodiment, water pump 3 can be kept operating near its highest efficiency point at its rated speed. The water flow rate of water pump 3 is M1 (m3 < M1), and the head is H1 (h3 + dh3 > H1) (where dh3 is the flow resistance of the pipeline and accessories). Compared to the water supply demand of the boiler system, the flow rate of water pump 3 is higher and the head is lower at this point. At this time, by adjusting the return regulating valve 5, a flow rate (M1-m3) higher than the required feedwater flow rate is returned through the return pipe 4, driving the jet pump 2 to work and pressurize the feedwater entering from the inlet pipe 1. The pressurization value is (h3+dh3-H1). In this way, the overall output feedwater flow rate of the feedwater system is still m3, and the feedwater head is h3, which meets the requirements of the boiler system. Moreover, the feedwater pump operates near the highest efficiency at the rated speed, without the need for a frequency converter, and the equipment is in good operating condition.

[0049] In the above embodiment, the water flow rate output by the water supply system through the outlet pipe 7 is always equal to the water flow rate demand under the corresponding operating conditions. Specifically, the water flow rate output from the outlet pipe 7 can be adjusted to the water flow rate demand under the corresponding operating conditions by adjusting the opening of the water supply regulating valve 6.

[0050] In one embodiment, the water supply system further includes a controller, and both the backflow regulating valve 5 and the water supply regulating valve 6 are electric valves. The jet pump 2, the water supply pump 3, the backflow regulating valve 5, and the water supply regulating valve 6 are all electrically connected to the controller to achieve automated control.

[0051] The adaptive feedwater system provided by this invention, by configuring jet pumps and defining their operational requirements, enables the joint operation of jet pumps and feedwater pumps. This satisfies the varying flow and head requirements of the boiler system under changing operating conditions, ensuring the feedwater pump operates near its highest efficiency point during these changes. This improves equipment efficiency, reduces noise levels, and guarantees the overall performance of the system. Furthermore, under certain circumstances, the feedwater pump frequency converter can be eliminated, replacing the variable-speed feedwater pump with a constant-speed pump, reducing the cost of the pump set and improving its reliability.

[0052] Please see Figure 2 The present invention also provides a control method for an adaptive water supply system as described above, comprising the following steps:

[0053] Step S1: Obtain the water supply flow requirement for the operating condition;

[0054] Step S2: Determine whether the water supply flow demand is the maximum flow of the water supply system. If yes, proceed to step S3; otherwise, proceed to steps S4 and S5.

[0055] Step S3: Adjust the water flow rate of the water pump to the rated flow rate, close the backflow regulating valve and the jet pump, and adjust the opening of the water regulating valve so that the water flow rate output from the outlet pipe is the water flow rate demand. The water flowing into the inlet pipe is transported to the outlet pipe by the water pump.

[0056] Step S4: Adjust the water flow rate of the water pump to be greater than the water flow demand and less than or equal to the rated flow rate. Adjust the opening of the water supply regulating valve so that the water flow rate output from the outlet pipe is the water flow demand. Adjust the opening of the return regulating valve so that the water output from the water pump that is higher than the water flow demand flows into the jet pump through the return pipe, thereby driving the jet pump to start.

[0057] In step S5, the jet pump mixes and pressurizes the water flowing into the return pipe and the inlet pipe, and then delivers it to the outlet pipe via the feed pump.

[0058] In step S2 above, the step of determining whether the water supply flow demand is the maximum flow of the water supply system is to determine whether the water supply system is used for the first operating condition or the second operating condition based on the water supply flow demand. The operating condition in which the water supply flow demand is the maximum flow of the water supply system is set as the first operating condition, and the operating condition in which the water supply flow demand is not the maximum flow of the water supply system (i.e., the water supply flow demand is less than the maximum flow of the water supply system) is set as the second operating condition.

[0059] Step S3 described above is the control method of the water supply system under the first operating condition, and steps S4 to S5 described above are the control methods of the water supply system under the second operating condition. For details, please refer to the description in the above embodiments, which will not be repeated here.

[0060] The boosting value of the jet pump on water is equal to the head requirement plus the flow resistance minus the head of the feed pump. The head of the feed pump has a first mapping relationship with the feed flow rate under the corresponding operating conditions, and the boosting value of the jet pump on water has a second mapping relationship with the opening degree of the return regulating valve.

[0061] Therefore, adjusting the opening of the reflux regulating valve in step S4 includes the following steps:

[0062] Based on the difference between the required head value and the head value of the feed water pump, and the second mapping relationship, the opening of the reflux regulating valve is adjusted so that the head value of the feed water delivered to the outlet pipe by the feed water pump is the required head value.

[0063] Specifically, when the difference between the required head and the feed pump head is large, the opening of the reflux regulating valve can be increased to increase the pressure of the water delivered to the feed pump via the jet pump; conversely, when the difference is small, the opening of the reflux regulating valve can be decreased to decrease the pressure of the water delivered to the feed pump via the jet pump. It is understandable that the water pressure delivered to the feed pump via the jet pump is positively correlated with the feed pump head of the water supply system.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for an adaptive water supply system, characterized in that, The adaptive water supply system includes an inlet pipe, a jet pump, a feed pump, a return pipe, a return regulating valve, a feed regulating valve, and an outlet pipe. The jet pump and the water supply pump are connected in series between the inlet pipe and the outlet pipe. The first inlet of the jet pump is connected to the inlet pipe, the second inlet of the jet pump is connected to one end of the return pipe, the outlet of the jet pump is connected to the inlet of the water supply pump, the outlet of the water supply pump is connected to the outlet pipe, and the other end of the return pipe is connected to the outlet pipe. The water supply regulating valve is installed on the outlet pipe. The water flow rate on the outlet pipe is controlled by adjusting the opening of the water supply regulating valve. The return regulating valve is installed on the return pipe. The start and stop of the jet pump and the water pressure flowing from the jet pump to the water supply pump are controlled by adjusting the opening of the return regulating valve. Includes the following steps: Step S1: Obtain the water supply flow requirement for the operating condition; Step S2: Determine whether the water supply flow demand is the maximum flow of the water supply system. If yes, proceed to step S3; otherwise, proceed to steps S4 and S5. Step S3: Adjust the water flow rate of the water supply pump to the rated flow rate, close the backflow regulating valve and the jet pump, and adjust the opening of the water supply regulating valve so that the water flow rate output from the outlet pipe is the required water flow rate. The water flowing into the inlet pipe is transported to the outlet pipe by the water supply pump. Step S4: Adjust the water flow rate of the water supply pump to be greater than the required water flow rate and less than or equal to the rated flow rate; adjust the opening of the water supply regulating valve so that the water flow rate output from the outlet pipe is the required water flow rate; adjust the opening of the return regulating valve so that the water output from the water supply pump, which is higher than the required water flow rate, flows through the return pipe to the jet pump, thereby driving the jet pump to start. In step S5, the jet pump mixes and pressurizes the water flowing into the return pipe and the inlet pipe, and then delivers it to the outlet pipe via the water supply pump.

2. The control method for the adaptive water supply system according to claim 1, characterized in that, The boosting value of the jet pump to water = head requirement + flow resistance - head of the feed pump, wherein the head of the feed pump has a first mapping relationship with the rotational speed corresponding to the feed flow rate under the corresponding operating conditions, and the boosting value of the jet pump to water has a second mapping relationship with the opening degree of the return regulating valve. In step S4, adjusting the opening of the reflux regulating valve includes the following steps: Based on the difference between the required head value and the head value of the feed water pump, and the second mapping relationship, the opening of the reflux regulating valve is adjusted so that the head value of the feed water delivered to the outlet pipe by the feed water pump is the required head value.

3. The control method for the adaptive water supply system according to claim 1, characterized in that, Under the first operating condition, the water supply flow rate of the water supply system is the maximum flow rate, the water supply flow rate of the water supply pump is the rated flow rate and equal to the water supply flow rate requirement under the first operating condition, the backflow regulating valve is closed, and the jet pump is shut down. In the second operating condition, the water supply flow rate of the water supply system is less than the maximum flow rate, the water supply flow rate of the water supply pump is greater than the water supply flow rate requirement of the second operating condition but less than or equal to the rated flow rate, the return regulating valve is opened, and the water output by the water supply pump that is higher than the water supply flow rate requirement of the second operating condition flows through the return pipe to the jet pump to drive the jet pump to start.

4. The control method for the adaptive water supply system according to claim 3, characterized in that, When the jet pump is turned on, the water in the return pipe and the inlet pipe are mixed and pressurized in the jet pump and then flow to the inlet of the water supply pump. The pressurization value of the jet pump on the water = head requirement value + flow resistance value - head value of the water supply pump. The head of the water supply pump is correlated with the water flow rate under the corresponding operating conditions in a first mapping relationship, and the pressure boosting value of the jet pump is correlated with the opening degree of the reflux regulating valve in a second mapping relationship. The opening degree of the reflux regulating valve is adjusted according to the difference between the head requirement value and the head of the water supply pump and the second mapping relationship, so that the head of the water supplied to the outlet pipe by the water supply pump is the head requirement value.

5. The control method for an adaptive water supply system according to claim 4, characterized in that, The head value of the water supply pump under the first operating condition is the sum of the head requirement value and the flow resistance value under the first operating condition. The head value of the water supply pump under the second operating condition is less than or equal to the head value of the water supply pump under the first operating condition.

6. The control method for the adaptive water supply system according to claim 5, characterized in that, Under the second operating condition, when the head requirement value of the second operating condition is equal to the head requirement value of the first operating condition, the water flow rate of the water supply pump is greater than the water flow rate requirement of the second operating condition and less than the rated flow rate, and the head value of the water supply pump is less than the sum of the head requirement value of the second operating condition and the flow resistance value.

7. The control method for an adaptive water supply system according to claim 5, characterized in that, In the second operating condition, when the head requirement value of the second operating condition is greater than the head requirement value of the first operating condition, the water supply flow rate of the water pump is equal to the rated flow rate, and the head value of the water pump is equal to the head value of the water pump in the first operating condition.

8. The control method for the adaptive water supply system according to claim 1 or 3, characterized in that, The water supply system outputs a flow rate equal to the water supply flow rate requirement under the corresponding operating conditions through the outlet pipe. The water flow rate output from the outlet pipe is adjusted to the water supply flow rate requirement under the corresponding operating conditions by adjusting the opening of the water supply regulating valve.

9. The control method for the adaptive water supply system according to claim 1, characterized in that, It also includes a controller, and both the reflux regulating valve and the water supply regulating valve are electric valves. The jet pump, the water supply pump, the reflux regulating valve, and the water supply regulating valve are all electrically connected to the controller.

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