Part 5: Equipment-level inspection and operation and maintenance SOP of the fire protection and safety protection system on the energy storage side of the photovoltaic power station
This article corresponds to the panoramic topology diagram of the energy storage power station [Module 5: Fire Protection and Safety Protection System], covering the heptafluoropropane/aerosol gas fire extinguishing system, nitrogen drive device, combustible gas (CO/H2/VOC) probe, aspirated smoke detector (ASD), fire alarm control panel (FACP), extravehicular emergency shutdown button (EPO), automatic fire linkage cut-off logic and Pack-level water spray backup fire protection system.
1. Gas fire extinguishing system (heptafluoropropane HFC-227ea / aerosol) equipment level maintenance SOP
The gas fire extinguishing system is the first automatic fire-extinguishing barrier when early thermal runaway or open fire occurs inside the battery compartment.
(1) Inspection of fire extinguishing agent gas storage cylinder and driving device
Fire extinguishing agent cylinder pressure and weighing inspection: Check the pressure gauge of the heptafluoropropane (HFC-227ea) gas storage cylinder. In an environment of 20°C, the pointer must be in the green qualified area (2.5 ~ 4.2 MPa). If the pointer drops to the red area, it means that the gas pressure is leaking and must be refilled.
Weighing Test (Annual): Cylinders are weighed and rechecked. When the net weight of the fire-extinguishing agent is reduced by >5% from the initial nominal mass, the cylinder must be removed to replenish the fire-extinguishing agent. Check that the cylinder hoop and anti-vibration rubber gasket are tight and not loose.
Nitrogen-driven small cylinder and solenoid valve (Solenoid Valve): Check the pressure of the nitrogen-driven small cylinder (standard pressure is 6.0 ± 0.2 MPa).
Check the solenoid drive valve electric explosion coil impedance (usually 20 ~ 50 Ω). Check that the mechanical safety pin (Safety Pin) on the solenoid driven valve must be in the released/pull-out standby state to ensure that the solenoid valve can successfully penetrate the cylinder ejector pin during automatic alarm.
(2) Gas fire extinguishing pipe network, selection valve and nozzle
Prevent clogging of nozzles and pipe networks: Check that there are no physical obstructions on the cabin roof and Pack-level gas nozzles, as well as no dust accumulation and oil condensation.
Anti-backflow one-way valve and high-pressure hose: Check that the high-pressure stainless steel metal hose has no cracks or deformation, and the anti-backflow one-way valve is installed in the correct direction and has no trace of leakage.
2. Maintenance SOP for combustible gas detection, smoke/temperature sensor and fire alarm control panel (FACP)
(1) Detector probe calibration and cleaning
All-in-one gas detector: focuses on detecting carbon monoxide (CO), hydrogen (H2), and combustible gas (VOC/methane). The probe indicator light flashes normally (the green light is always on/flashes to indicate normal communication).
Aspirating smoke detector (ASD/VESDA): Check that the air inlet of the aspiration sampling pipe network is not blocked, clean or replace the high-efficiency air filter (HEPA) inside the sampling host; check that the operating current of the air extraction pump and the sampling wind speed are normal.
Smoke and temperature sensing probes: Every six months, use a portable smoke tester and a hot air gun to randomly test the smoke and heat sensitivity of the smoke and temperature sensing probes in the cabin. The response time of the probe must be < 3s, and the main control panel must accurately display the corresponding probe code address.
(2) Fire Alarm Control Panel (FACP - Fire Alarm Control Panel)
Main/backup power automatic switching test: disconnect the FACP main AC power supply (220V AC), and the control panel must seamlessly switch to the backup battery power supply (DC 24V). The backup battery can maintain the control panel's normal monitoring operation time ≥ 24 hours.
Bus communication and shielding self-test: Check that the FACP main screen displays no “fire alarm”, “fault” or “loop shielding” indicator lights.
3. Actual test SOP of extravehicular emergency control panel (EPO) and fire linkage cut-off logic
(1) Extravehicular control panel and manual/automatic switching
Control mode key switch: Check the fire control box next to the hatch. The "manual/automatic" selector switch must be in the "Auto" position all year round.
Emergency stop button (EPO): Check that the mechanical yellow-black protective cover of the red EPO button is intact and not damaged by accidental contact.
(2) Fire safety automatic linkage cut-off logic (millisecond test SOP)
Test cycle: actual measurement using simulated signals once every six months.
Linkage logic and response timing:
Step 1: The fire control panel receives a second-level fire alarm (smoke + temperature sensors are triggered at the same time, or the CO / H2 concentration reaches the deflagration warning line).
Step 2: Start the 30-second audible and visual alarm countdown (to give on-site operation and maintenance personnel time for emergency evacuation, while the outdoor audible and visual alarm will sound wildly).
Step 3: Before the countdown ends (millisecond level), the control panel outputs a dry contact signal to trigger the following three linkage actions:
Action 1: Forcibly cut off the DC main circuit breaker of the battery compartment (trip the BDU/BCU high-voltage contactor and cut off the energy source).
Action 2: Forcibly cut off the power supply to the HVAC air conditioner and the inlet and outlet fans in the cabin to stop the air flow.
Action 3: Close the hatch and air duct fire damper (Damper) to form a confined space.
Step 4: When the countdown is over, start the nitrogen driven valve ➔ Break down the thimble of the heptafluoropropane cylinder ➔ Release the gas fire extinguishing agent ➔ Leave the cabin to suffocate for no less than 20 minutes.
4. Pack-level water sprinkler/submersible backup cooling and fire protection system maintenance
When the battery continues to heat up out of control after the gas fire extinguishing is released, the backup water fire protection system starts to perform powerful cooling.
Fire water inlet pipe and quick-change interface: Check that the standard outdoor fire truck water pump adapter (DN65 or DN80 interface) is free of rust and stuck, and that the rubber dust cover is intact. Check that the antifreeze drain valve of the pipe network is open and drained to prevent water from freezing and cracking the pipes in winter. A 1.0 MPa water pressure withstand test is conducted annually.
Pack-level solenoid water valves and nozzles: Check the insulation resistance of the solenoid water valve coil corresponding to each Pack (≥ 50 MΩ); check that the dust cap (Dust Cap) of the water spray open nozzle is intact.
Photovoltaic power station energy storage side fire protection and safety protection system equipment level inspection on-site inspection sign-in form
Power station name: _______________________________ Inspection date: ____ month ____ day, 2026
Inspection area: Extravehicular fire cylinder area and fire control panel Inspection person in charge: ____________________
1. Field equipment inspection and test data records:
2. Inspection defect registration and defect elimination dispatch:
3. Inspection sign-in and review signature:
Inspection engineer (signature): _______________ Supervision engineer (signature): _______________
Review (signature) of the shift leader: _______________ Sign-in and filing time: ____ hour on ____ month ____ day 2026