I. Tender Background and Core Requirements: In winter 2025, a municipal sanitation department in Harbin issued a procurement notice for new Dongfeng sewage treatment vehicles to address issues of aging pipeline dredging and insufficient sewage treatment capacity within its jurisdiction. According to publicly released tender information, the project budget is capped at approximately RMB 941,000, with plans to procure two National VI emission-standard sewage treatment vehicles, primarily intended for emergency pumping and drainage, slurry-water separation, and preliminary purification operations in urban stormwater and sewage pipelines. Given Harbin’s frigid climate—where winter temperatures can drop as low as -35°C—the tender documents specifically emphasize three core requirements: 1. Freeze-Resistant Starting Performance: Vehicles must start reliably at -30°C; hydraulic systems and pump piping must be equipped with preheating or anti-freeze devices. 2. Low-Temperature Hydraulic Stability: Hydraulic oil must be low-temperature resistant (e.g., HV series), and all hydraulic valves and piping must maintain sealing integrity at sub-zero temperatures to prevent operational failure due to oil solidification. 3. Winter Maintenance Plan: Bidders must provide a detailed winter operation manual, including antifreeze replacement intervals, anti-freezing measures for water storage tanks, and comprehensive machine hibernation protection protocols. II. Chengli Technical Response Proposal Chengli Special Purpose Vehicle Co., Ltd. (hereinafter referred to as “Chengli”) developed a specialized customization based on the Dongfeng chassis (model reference: CLW5180GSSD6, per official announcement parameters) to meet the above core requirements. The technical response is as follows: 1. Freeze-Resistant Starting System Chengli equipped the tender vehicles with an engine intake preheating system and a fuel-water heater. At -30°C, after connecting to an external power source, the heater pre-warms the engine coolant, raising the engine block temperature to above -5°C within 15 minutes. Combined with a low-temperature starting battery, this ensures over 99% one-button start success rate. Additionally, the sewage treatment pump assembly features electric heat-tracing insulation to prevent pipe freezing. 2. Low-Temperature Hydraulic Stability The hydraulic system uses HV-46 low-temperature hydraulic oil (pour point below -40°C), and an oil temperature heater is installed on the hydraulic tank. When oil temperature falls below -10°C, the heater automatically activates, ensuring stable hydraulic power output even under extreme cold. All hydraulic hard lines are fabricated from 304 stainless steel to prevent brittle fracture at low temperatures. 3. Winter Maintenance Plan Chengli included a complimentary 'Winter Operation Guide for Sewage Treatment Vehicles in Frigid Regions' in its tender submission. Key provisions include: - After daily operations, residual wastewater in the sewage tank must be fully drained and piping flushed with clean water to prevent ice blockages. - Antifreeze freeze point must be inspected every 30 days (must remain below -40°C). - For long-term storage, hydraulic oil must be heated to 15°C and circulated for 5 minutes before power shutdown. III. Commercial Quotation Strategy Chengli’s quotation references price ranges for comparable models in its knowledge base (e.g., 5-cubic-meter street sweepers priced at ~RMB 310,000–387,000); however, sewage treatment vehicles are special-purpose modified units requiring independent cost calculation. The final unit price is approximately RMB 459,000, totaling RMB 830,000 for two units—well below the budget ceiling—and includes all low-temperature modification accessories plus a 2-year full-vehicle warranty. The core of Chengli’s pricing strategy is: - Transparent Configuration List: All value-added components—including low-temperature heating systems, hydraulic oil heaters, and electric