Drain solenoid valve power supply loop of DEH system
By connecting the drain solenoid valve in the DEH system to each DO relay board in parallel and connecting the fuse to supply power independently, the problem of all power loss of the drain solenoid valve is solved, and the safety and operational economy of the unit are improved.
Patent Information
- Application Number
- CN202421538626.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-01
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-07-01
AI Technical Summary
The existing DEH system drain solenoid valve power circuit design has the problem of all drain solenoid valves losing power, which has affected the safe operation of the unit.
Multiple drain solenoid valves are connected in parallel on each DO relay board, and fuses are connected to their positive and negative poles. Each DO relay board is independently connected to a thermal power supply and power is supplied through an air switch to prevent the fuse from being blown when a single drain solenoid valve loses power.
It effectively avoids all power loss of drainage solenoid valves, reduces troubleshooting time, improves unit safety and operational economy, and reduces the risk of unplanned shutdowns.
Smart Images
Figure CN223137109U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of thermal control, in particular to a power supply circuit for a drain solenoid valve. Background Technique
[0002] The digital electro-hydraulic control system is abbreviated as the DEH control system. The DEH system is responsible for the speed and load control of the steam turbine generator set. The reliability of its system power supply is one of the key factors for the safe and stable operation of thermal power units.
[0003] The drain solenoid valve control circuits of Units 1 and 2 of Panji Power Plant are distributed on four DO relay boards C1, C2, C3, and C4 in the EXT44-1 cabinet in the DCS electronic room. As Figure 1 shown, the upper ports of terminal blocks TB1 and TB2 respectively correspond to a thermal control 220V power supply. 32 drain solenoid valves on DO relay boards C1 and C2 share a common upper-level power supply, and 32 drain solenoid valves on DO relay boards C3 and C4 share a common upper-level power supply. When any solenoid valve circuit on the four DO relay boards is short-circuited or grounded, it will cause the corresponding upper-port power supply to trip, and then the two DO relay boards under the air switch will lose power, and the drain solenoid valves will open fully, resulting in steam loss, causing the unit load to drop suddenly, the temperature of the drain pipeline to rise suddenly, and in severe cases, the steam turbine will switch to the pressure-limiting mode, causing the steam turbine control valves to close, resulting in the unit tripping, seriously affecting the safe operation of the unit and causing huge economic losses to the power plant. It can be seen that there are drawbacks in the design of the existing power supply circuit for the drain solenoid valve of the DEH system, and it is necessary to redesign and optimize it. Content of the Utility Model
[0004] The technical problem to be solved by the utility model is to design a safe and reliable power supply circuit for the drain solenoid valve of the DEH system to solve the problem of all drain solenoid valves losing power.
[0005] The utility model solves the above technical problem through the following technical solutions: A power supply circuit for a drain solenoid valve of a DEH system includes a plurality of DO relay boards, each DO relay board is respectively connected to a thermal power supply, each DO relay board has a plurality of parallel drain solenoid valves, and a fuse is connected to the positive and negative poles of the circuit of each drain solenoid valve. One end of the drain solenoid valve is connected to one end of the first fuse, the other end of the first fuse is connected to the positive pole of the DO relay board, the positive pole of the DO relay board is connected to the positive pole of the air switch, the other end of the drain solenoid valve is connected to one end of the second fuse, the other end of the second fuse is connected to the negative pole of the DO relay board, and the negative pole of the DO relay board is connected to the negative pole of the air switch.
[0006] Preferably, it further includes terminal blocks TB1 and TB2, and each DO relay board is connected to the thermal power supply through terminal block TB1 or terminal block TB2.
[0007] Preferably, there are four of the DO relay boards and thermal power supplies. The DO relay board C1 is connected to the first thermal power supply, the DO relay board C2 is connected to the second thermal power supply, the DO relay board C3 is connected to the third thermal power supply, and the DO relay board C4 is connected to the fourth thermal power supply.
[0008] Preferably, the number and wiring method of the drain solenoid valves on the four DO relay boards are the same.
[0009] Preferably, both the first fuse and the second fuse are 1A fuses.
[0010] Preferably, the thermal power supply is a 220VAC power supply.
[0011] Preferably, the drain solenoid valves include a No. 1 ultra-high pressure governor valve front drain valve solenoid valve, a No. 2 ultra-high pressure governor valve front drain valve solenoid valve, a No. 1 ultra-high pressure outer cylinder drain valve solenoid valve, a No. 2 ultra-high pressure outer cylinder drain valve solenoid valve, an ultra-high pressure inner and outer cylinder interlayer drain valve solenoid valve, a No. 1 high pressure reheater main steam valve front drain valve solenoid valve, a No. 2 high pressure reheater main steam valve front drain valve solenoid valve, a steam seal leakage to medium and low pressure connecting pipe drain valve solenoid valve, a No. 1 high pressure reheater governor valve front drain valve solenoid valve, a No. 2 high pressure reheater governor valve front drain valve solenoid valve, a high pressure reheater governor valve rear drain valve solenoid valve, a No. 1 medium pressure reheater governor valve rear drain valve solenoid valve, a No. 2 medium pressure reheater governor valve rear drain valve solenoid valve, and an ultra-high pressure cold reheat check valve front drain valve solenoid valve.
[0012] The advantages provided by the present utility model are as follows:
[0013] 1. Aiming at the drawback that all drain solenoid valves in the existing DEH system drain solenoid valve power circuit are de-energized, the present utility model optimizes and improves the DEH system drain solenoid valve power circuit. In the improved power circuit, each DO relay board is independently powered by connecting to a thermal power supply. A fuse is added to the positive and negative poles of the circuits of all solenoid valves on the DO relay board. When the control circuit of a single drain solenoid valve is grounded and short-circuited, the corresponding fuse can be blown, avoiding all drain solenoid valves from being de-energized. Each DO relay board takes one path of the upstream air switch for power supply, which can effectively prevent the expansion of the fault point. After a single circuit fails, it will not cause the air switch to trip. Only the problematic fuse needs to be replaced, which can effectively reduce the troubleshooting and elimination time of maintenance personnel and improve the safety of the unit.
[0014] 2. The present utility model can effectively prevent the air switch from tripping due to the abnormality of a single solenoid valve circuit, avoid the drain valve from being fully opened, and reduce the risk of unplanned shutdown of the unit. Calculated based on 0.5 misoperation per unit during the service period, and a total of 1 misoperation during the service period is accounted for. The economic benefit of this transformation is 2.481 million yuan. Description of the Drawings
[0015] Figure 1 It is a schematic diagram of the power supply circuit of the drain solenoid valve of the existing DEH system;
[0016] Figure 2 It is a schematic diagram of the power supply circuit of the drain solenoid valve of the DEH system provided by the embodiment of the present invention;
[0017] In the figure: 1-1, the drain solenoid valve of the No. 1 high-pressure regulating valve before superheat; 1-2, the drain solenoid valve of the No. 2 high-pressure regulating valve before superheat; 2-1, the drain solenoid valve of the No. 1 steam supply make-up valve after; 2-2, the drain solenoid valve of the No. 2 steam supply make-up valve after; 3, the drain solenoid valve of the superheat high-pressure inner and outer cylinder interlayer; 4-1, the drain solenoid valve of the No. 1 high-pressure reheat main steam valve before; 4-2, the drain solenoid valve of the No. 2 high-pressure reheat main steam valve before; 5, the drain solenoid valve of the steam seal leakage to the medium and low pressure connecting pipe; 6-1, the drain solenoid valve of the No. 1 high-pressure reheat regulating valve before; 6-2, the drain solenoid valve of the No. 2 high-pressure reheat regulating valve before; 7, the drain solenoid valve after the high-pressure reheat regulating valve; 8, the drain solenoid valve of the superheat high-pressure outer cylinder; 9, the drain solenoid valve after the medium-pressure reheat regulating valve; 10, the drain solenoid valve before the superheat cold reheat check valve. Detailed Embodiment
[0018] In order to make the purpose, technical solutions and advantages of the present invention clearer and more understandable, the following combines specific embodiments and refers to the drawings to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.
[0019] This embodiment provides a power supply circuit for the drain solenoid valve of the DEH system, which includes a plurality of DO relay boards. Each DO relay board is respectively connected to a thermal power supply, and a plurality of parallel drain solenoid valves are provided on each DO relay board. Figure 2 The shown is the wiring diagram of one of the DO relay boards C1. The drain solenoid valves connected to the remaining DO relay boards are the same as those of the DO relay board C1. A fuse is added to the positive and negative poles of the circuit of each drain solenoid valve. One end of the drain solenoid valve is connected to one end of the first fuse, the other end of the first fuse is connected to the positive pole of the DO relay board, the positive pole of the DO relay board is connected to the positive pole of the air switch, the other end of the drain solenoid valve is connected to one end of the second fuse, the other end of the second fuse is connected to the negative pole of the DO relay board, and the negative pole of the DO relay board is connected to the negative pole of the air switch.
[0020] It also includes terminal block TB1 and terminal block TB2. Each DO relay board is connected to the thermal power supply through terminal block TB1 or terminal block TB2. The positive pole of the DO relay board is connected to the positive pole of the thermal power supply, and the negative pole of the DO relay board is connected to the negative pole of the thermal power supply.
[0021] The thermal power supply is a 220VAC power supply. Both the first fuse and the second fuse are 1A fuses.
[0022] There are four DO relay boards and four thermal power supplies, namely DO relay board C1, DO relay board C2, DO relay board C3, and DO relay board C4. DO relay board C1 is connected to the first thermal power supply, DO relay board C2 is connected to the second thermal power supply, DO relay board C3 is connected to the third thermal power supply, and DO relay board C4 is connected to the fourth thermal power supply.
[0023] The drain solenoid valves include the first drain solenoid valve before the ultra-high pressure governor valve, the second drain solenoid valve before the ultra-high pressure governor valve, the first drain solenoid valve of the ultra-high pressure outer cylinder, the second drain solenoid valve of the ultra-high pressure outer cylinder, the drain solenoid valve of the ultra-high pressure inner and outer cylinder interlayer, the first drain solenoid valve before the high-pressure reheater main steam valve, the second drain solenoid valve before the high-pressure reheater main steam valve, the drain solenoid valve for steam seal leakage to the medium and low pressure connecting pipe, the first drain solenoid valve before the high-pressure reheater governor valve, the second drain solenoid valve before the high-pressure reheater governor valve, the drain solenoid valve after the high-pressure reheater governor valve, the first drain solenoid valve after the medium-pressure reheater governor valve, the second drain solenoid valve after the medium-pressure reheater governor valve, and the drain solenoid valve before the ultra-high pressure cold reheat check valve.
[0024] In view of the drawback that all drain solenoid valves in the existing drain solenoid valve power circuit of the DEH system lose power, the present utility model optimizes and improves the drain solenoid valve power circuit of the DEH system. In the improved power circuit, each DO relay board is independently powered by connecting to a thermal power supply. A fuse is added to the positive and negative poles of the circuits of all solenoid valves on the DO relay board, so that when the control circuit of a single drain solenoid valve is grounded and short-circuited, the corresponding fuse will blow, avoiding all drain solenoid valves from losing power. Each DO relay board takes one path of the upstream air switch for power supply, which can effectively prevent the expansion of the fault point. After a single circuit fails, it will not cause the air switch to trip, and only the problematic fuse needs to be replaced, which can effectively reduce the troubleshooting and elimination time of maintenance personnel and improve the safety and operation economy of the unit.
[0025] Through this transformation, on the one hand, it effectively avoids the misoperation caused by the abnormality of the DEH drain solenoid valve power circuit and prevents the unplanned shutdown of the unit; on the other hand, it improves the reliability of the DEH drain solenoid valve power circuit and effectively guarantees the safe and stable operation of the unit and the safety of equipment. Calculated based on 0.5 misoperation per unit during the service period, a total of 1 misoperation is calculated during the service period.
[0026] 1. According to the relevant provisions of the "Implementation Rules for the Grid-Connected Operation Management of Power Plants in the East China Region", for a normally operating generating unit that suddenly trips, the electricity quantity to be deducted each time is:
[0027]
[0028] In the formula, Q 非停 is the electricity quantity to be deducted, P N is the unit capacity (megawatt), is the unit outage hours (hours), with a maximum of 72 hours, and α 非停 is the coefficient for the assessment of unscheduled outages, with a value of 0.2. Calculated based on an outage of 5 hours, the electricity quantity to be deducted is:
[0029] Q 非停 = 0.5×660×1000×5×0.2 = 330000 kW·h
[0030] 2. From the time of the unit trip until the cause of the trip is identified and it is ready to restart the unit, during this period, calculated based on 5 hours and a unit load of 660 MW, the lost electricity quantity is approximately:
[0031] Q = 5×660×1000 = 3300000 kW·h
[0032] The total consumption of oil, water, etc. during the restart of the unit is approximately 1 million yuan.
[0033] During the process of burning oil during unit startup, environmental pollution will be caused, which does not conform to the relevant policies on energy conservation and emission reduction.
[0034] Table 1 is the economic summary table of the losses caused by a single unit outage:
[0035] Table 1 Economic Summary Table of Losses Caused by a Single Unit Outage
[0036]
[0037] The economic benefit of this transformation is 2.481 million yuan. The power supply circuit of the DEH solenoid valve after transformation can effectively avoid the trip of the air switch caused by the abnormality of a single solenoid valve circuit, prevent the full opening of the drain valve, thereby reducing the risk of unscheduled outages of the unit and improving the reliability of the unit protection settings. At the same time, the investment cost of this transformation is small, the effect is obvious, and the safety benefit after transformation is high, improving the operation safety of the unit and reducing the risk of misoperation of the DEH solenoid valve air switch. It broadens the thinking for other retrofit work and has reference significance for the planning, preparation, construction, etc. of future other retrofit projects.
[0038] 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. A power supply circuit for a drain solenoid valve of a DEH system, characterized in that: It includes multiple DO relay boards, each of which is connected to a thermal power supply respectively. There are multiple parallel-connected drain solenoid valves on each DO relay board. The positive and negative poles of the circuit of each drain solenoid valve are connected to a fuse. One end of the drain solenoid valve is connected to one end of the first fuse, the other end of the first fuse is connected to the positive pole of the DO relay board, the positive pole of the DO relay board is connected to the positive pole of the air switch, the other end of the drain solenoid valve is connected to one end of the second fuse, the other end of the second fuse is connected to the negative pole of the DO relay board, and the negative pole of the DO relay board is connected to the negative pole of the air switch.
2. The DEH system drain solenoid valve power supply circuit according to claim 1, wherein: It also includes terminal block TB1 and terminal block TB2. Each DO relay board is connected to the thermal power supply through terminal block TB1 or terminal block TB2.
3. The power supply circuit of the drain solenoid valve of the DEH system according to claim 1, wherein: There are four DO relay boards and four thermal power supplies. DO relay board C1 is connected to the first thermal power supply, DO relay board C2 is connected to the second thermal power supply, DO relay board C3 is connected to the third thermal power supply, and DO relay board C4 is connected to the fourth thermal power supply.
4. The power supply circuit of the drain solenoid valve of the DEH system according to claim 1, characterized in that: The number and wiring method of the drain solenoid valves on the four DO relay boards are the same.
5. The power supply circuit of the drain solenoid valve of the DEH system according to claim 1, characterized in that: Both the first fuse and the second fuse are 1A fuses.
6. The power supply circuit of the drain solenoid valve of the DEH system according to claim 1, wherein: The thermal power supply is a 220VAC power supply.
7. The power supply circuit of the drain solenoid valve of the DEH system according to claim 1, characterized in that: The drain solenoid valves include the No. 1 super-high pressure throttle valve front drain solenoid valve, the No. 2 super-high pressure throttle valve front drain solenoid valve, the No. 1 super-high pressure outer cylinder drain solenoid valve, the No. 2 super-high pressure outer cylinder drain solenoid valve, the super-high pressure inner and outer cylinder interlayer drain solenoid valve, the No. 1 high-pressure reheater main steam valve front drain solenoid valve, the No. 2 high-pressure reheater main steam valve front drain solenoid valve, the steam seal leakage to the medium and low pressure connecting pipe drain solenoid valve, the No. 1 high-pressure reheater throttle valve front drain solenoid valve, the No. 2 high-pressure reheater throttle valve front drain solenoid valve, the high-pressure reheater throttle valve rear drain solenoid valve, the No. 1 medium-pressure reheater throttle valve rear drain solenoid valve, the No. 2 medium-pressure reheater throttle valve rear drain solenoid valve, and the super-high pressure cold reheat check valve front drain solenoid valve.