Copes Vulcan turbine bypass system (CV-1163)

System positioning and core values

The Copes Vulcan bypass system is a critical protection and regulation equipment for power plants, used for steam control between boilers and turbines.

Service history: supplied since the 1950s, adapted to dry state superheater and reheater cooling in the 1960s

Modern demand:

Shorten boiler/turbine commissioning time and enable independent testing

Steam/metal temperature matching during hot and cold start-up

Suppress boiler pressure fluctuations during turbine trip

Prevent the high-pressure safety valve from tripping, reduce maintenance and condensate loss

Ensure cooling of reheater tube wall during start-up/tripping

Protect the condenser from overheating and overpressure

Industry status: With over 90 years of experience in power generation equipment, we are a global agency and service center with over 50+agents

Core valve type and parameters

The document focuses on introducing 5 types of bypass valves, with the following key parameters:

Core characteristics of pressure rating for valve type structure

DSCV forged valve body, customized top mounted internal parts Class 600~4500, noise reduction, online maintenance

TE-PRDS top mounted temperature and pressure reduction class 150-2500 quick change internal parts, online maintenance

PRDS Classic Temperature and Pressure Reduction Class 600~2500, Reliable Application for 40 Years

HP bypass valve cage guide+HUSH ® Maximum 220bar quick open, fail open upon power failure

LP bypass valve with large diameter, equipped with diffusion pipe Class 150-900 to protect the condenser, fail close when power is lost

Size range: 1 × 2 “~8 × 16” (25 × 50mm~200 × 400mm)

Closing level: Maximum ANSI/FCI 70-2 Class V

Temperature upper limit: 590 ℃ (1100 ° F)

Pressure upper limit: 220bar (3200pig)

Key technologies and internal components

HUSH ®  Multi stage pressure reducing internal components

Function: graded pressure reduction, active noise reduction, anti cavitation

Configuration: HP/LP bypass valve standard, ensuring dynamic stability

Cooling method

Suction type, mechanical atomization, steam atomization

Select based on steam/water flow ratio and water pressure

actuator

Hydraulic: fast and precise, used for HP bypass, equipped with HPU hydraulic station

Pneumatic: piston/diaphragm type, equipped with a speed reducer and quick release valve

Redundancy: Dual pumps, accumulator, power-off action guarantee

Algorithmic Temperature Control (ATC)

Principle: Based on the thermal equilibrium formula Qw=Q ₁× (h ₁− h ₂)/(h ₂− hw)

Input: inlet/outlet pressure, inlet steam temperature, flow rate

Advantage: Solve the problem of inaccurate temperature measurement within 5 ℃ in the saturation temperature zone

Diffusion tube&discharge pipe

Function: Final pressure reduction, steam diffusion, noise reduction

Installation: LP bypass direct insertion condenser, small hole silencing technology

Differences in HP/LP bypass design

High pressure (HP) bypass

Task: Quickly adjust the main steam of the boiler to the cold and reheat parameters

Action: In case of power failure, quickly open to prevent the safety valve from tripping

Execution: Priority hydraulic, extremely fast response speed

Low pressure (LP) bypass

Task: Adjust the reheated steam to the acceptable parameters of the condenser

Features: Large caliber, significant increase in steam specific volume

Action: Fault power loss shutdown, protect the condenser

Configuration: Must be equipped with discharge pipe/diffusion tube

Control and Safety Logic

Quick action

Steam turbine trip: valve opens quickly throughout the full stroke to prevent overpressure

Start control

Smooth heating, warming up, and boosting, matched with metal temperature

Special for back pressure unit

Trip to achieve undisturbed switching, downstream pressure fluctuation * *<1bar**

PLC pre calculates valve position, with a 2-second backtracking hold

Combined Heat and Power (CHP)

Provide a complete set of bypass, temperature and pressure reduction, water replenishment, and cooling water valve solutions

Single source supply reduces integration risks

Typical application cases

Synthesis gas/CO ₂ compressor drives turbine bypass

Valve type: 6 × 12 “Class 2500 DSCV

Control: Hydraulic station+PLC

Effect: Downstream pressure fluctuation * *<1bar during tripping**

Paper mill CHP power station

Complete set of bypass, temperature reduction, water replenishment, and drainage valve groups

Multi pressure level steam distribution control

Key issues

Question 1: What are the five core functions of the turbine bypass system?

answer:

Realize independent debugging of boilers and turbines to shorten start-up time

Match steam and metal temperature during startup to protect equipment

Quickly release pressure when the steam turbine trips to prevent the safety valve from tripping

Maintain the cooling of the reheater to prevent burning of the tube bundle

Protect the condenser from overheating and overpressure

Question 2: What are the key differences between HP bypass and LP bypass in terms of actuator, fault action, and core protection object?

answer:

HP bypass: commonly used hydraulic execution; Fault power loss quick opening; Protect the boiler, reheater, and main steam safety valve

LP bypass: commonly used hydraulic/pneumatic; Fault power failure shutdown; Protect the condenser from entering high-temperature and high-pressure steam

Question 3: What industry pain points does algorithmic temperature control (ATC) solve? What is its computational logic?

answer:

Pain point: Conventional temperature measurement results in distorted readings and uncontrolled temperature control due to water droplet adhesion within the saturation temperature range of 5 ℃

Logic: Real time calculation of required cooling water volume based on thermal balance formula

Qw=steam flow rate x (inlet enthalpy outlet enthalpy)/(outlet enthalpy water enthalpy)

Advantages: Extremely fast and precise, especially suitable for bypass scenarios of short tubes and direct discharge condensers