Zhejiang Petrochemical — LDPE/EVA (2020) — 560 kW Brine Chiller Package × 8 for Polyethylene Production

Zhejiang Petroleum & Chemical's LDPE/EVA unit produces low-density polyethylene and ethylene vinyl acetate copolymers via the high-pressure autoclave or tubular reactor process. LDPE is widely used in packaging films, wire and cable insulation, and squeeze bottles, while EVA copolymers serve the solar encapsulant, hot-melt adhesive, and foam industries.

Customer	Zhejiang Petroleum & Chemical Co., Ltd.
Plant / Unit	LDPE/EVA (Low-Density Polyethylene / Ethylene Vinyl Acetate)
Equipment	Brine Chiller Package
Design Institute	China Huanqiu Contracting & Engineering (Daqing)
Design Code	GB
Cooling Capacity	560 kW per unit
Motor Power	185 kW
Refrigerant	R507
Coolant	Ethylene glycol
Quantity	8 sets

Customer Background

Zhejiang Petroleum & Chemical’s LDPE/EVA unit produces low-density polyethylene and ethylene vinyl acetate copolymers via the high-pressure autoclave or tubular reactor process. LDPE is widely used in packaging films, wire and cable insulation, and squeeze bottles, while EVA copolymers serve the solar encapsulant, hot-melt adhesive, and foam industries.

LDPE production operates at extreme pressures (up to 300 MPa) and generates substantial reaction heat that must be removed across multiple stages: reactor jacket cooling, high-pressure separator cooling, low-pressure separator cooling, and extruder/pelletizer cooling. The eight-unit chiller configuration reflects the distributed cooling architecture typical of high-pressure PE plants, where multiple independent cooling loops serve different process stages with varying temperature and flow requirements.

Challenges and Engineering Requirements

Process Temperature Control in petrochemical processing

Zhejiang Petroleum & Chemical Co., Ltd. required precise low-temperature cooling for Brine Chiller Package service in the petrochemical processing sector. The brine chiller system must maintain stable outlet temperatures within narrow tolerances despite variable process heat loads. Fluctuations in feed composition, ambient temperature swings, and seasonal load variations all affect the refrigeration duty — the system must respond to these changes while protecting compressor operation from surge and liquid carryover.

Refrigerant Selection and Safety

The choice of R507 reflects the balance between thermodynamic efficiency at the target evaporating temperature, compatibility with the plant’s existing refrigerant infrastructure, and safety classification under the applicable code. Each refrigerant brings specific considerations: flammability limits for hydrocarbon refrigerants, operating pressure ranges that affect component sizing, and oil miscibility that influences compressor lubrication system design.

Integration with EPC Engineering

The chiller packages were specified and documented by China Huanqiu Contracting & Engineering (Daqing) as part of a larger process unit. This means every interface — brine supply/return connections, electrical load requirements, control signal protocols, and physical footprint — must match the EPC’s plot plan and P&ID exactly. Any deviation requires formal design change management, adding time and cost to the project.

Why Zhejiang Petroleum & Chemical Co., Ltd. Selected Lmart

Integrated refrigeration package capability. Lmart designs and manufactures complete refrigeration systems — compressor selection, heat exchanger sizing, piping layout, control logic, and skid-frame engineering — as a single-source supplier. This eliminates the interface risks that arise when the chiller vendor, vessel fabricator, and system integrator are separate companies.

Process refrigerant experience. Lmart has delivered refrigeration packages using propylene, propane, ammonia, R134a, and other process refrigerants across petrochemical, chemical, and marine applications. This experience base means the engineering team understands the specific requirements of each refrigerant — safety classifications, oil management, capacity control methods — without a learning curve.

Repeat performance. Lmart has delivered equipment to Zhejiang Petroleum & Chemical Co., Ltd. and similar clients in the petrochemical processing sector, demonstrating consistent quality and on-time delivery performance across multiple projects.

Engineering and Manufacturing Solution

Lmart engineered and fabricated Brine Chiller Package for Zhejiang Petroleum & Chemical Co., Ltd. to GB. The scope of supply included complete detail design, material procurement, fabrication, inspection, testing, and documentation.

Key engineering considerations for this project included thermal-hydraulic performance optimization, material selection for the specific process environment, and compliance with GB requirements for design, fabrication, and inspection.

The equipment was manufactured at Lmart’s Zhangjiagang facility, which provides full-cycle fabrication capabilities including plate rolling, head forming, machining, welding (SAW, GTAW, SMAW), post-weld heat treatment, and NDE — all under a single quality management system.

Delivery and Outcome

All eight packages were manufactured, factory-tested, and delivered in a coordinated sequence matching the LDPE/EVA unit’s installation schedule. The batch quantity of 8 units from a single manufacturer ensured interchangeability of components and consistent performance across the cooling network. This order — Lmart’s largest single-project unit count for brine chillers at the time — reinforced the company’s production capacity for multi-unit batch deliveries to major petrochemical complexes.

Results and Business Impact

Lmart successfully delivered Brine Chiller Package to Zhejiang Petroleum & Chemical Co., Ltd., meeting the project’s quality, schedule, and documentation requirements. The equipment was manufactured to GB standards, with full documentation packages accepted by the client and applicable inspection authorities.

This project reinforces Lmart’s position as a qualified manufacturer for petrochemical processing applications, demonstrating the company’s ability to deliver equipment that meets international quality and certification standards.

Customer Voice

“The equipment was delivered on schedule and the documentation package was complete. The quality of fabrication met our inspection requirements.”

— Zhejiang Petroleum & Chemical Co., Ltd. project team (paraphrased from project review)

Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.