Hengli Petrochemical — HDPE (2018) — Brine Chiller Package for Polyethylene Production
By Qiangbin Chu · Sales Manager & Operations Lead
Hengli Petrochemical is one of China's largest private-sector refining and petrochemical enterprises, operating an integrated refinery and chemical complex on Changxing Island, Dalian, Liaoning Province. The complex includes a 20 million tonne/year refinery and downstream units producing ethylene, propylene, PX, PTA, HDPE, PP, and other chemical intermediates. The HDPE unit produces high-density polyethylene resin for film, pipe, and blow-molding applications.
| Client | Hengli Petrochemical (Changxing Island, Dalian) |
| Plant / Unit | HDPE — High-Density Polyethylene |
| Equipment | Brine Chiller Package × 3 |
| Design Code | GB |
| Cooling Capacity | 1,034 / 2,200 kW (dual duty point) |
| Motor Power | 560 kW / 630 kW |
| Refrigerant | Propylene (R1270) |
| Coolant | n-Hexane / iso-hexane |
| Design Institute | SEI (Sinopec Engineering Incorporation) |
| Year | 2018 |
Customer Background
Hengli Petrochemical is one of China’s largest private-sector refining and petrochemical enterprises, operating an integrated refinery and chemical complex on Changxing Island, Dalian, Liaoning Province. The complex includes a 20 million tonne/year refinery and downstream units producing ethylene, propylene, PX, PTA, HDPE, PP, and other chemical intermediates. The HDPE unit produces high-density polyethylene resin for film, pipe, and blow-molding applications.
In HDPE slurry-loop and gas-phase processes, solvent cooling is critical for controlling polymerization temperature. The n-hexane/iso-hexane solvent must be chilled to precise temperatures before recirculation. Insufficient cooling capacity or temperature instability directly affects polymer molecular weight distribution, product consistency, and plant throughput.
Hengli’s HDPE unit is part of a 1.5 million tonne/year ethylene complex that represented one of the largest single-phase petrochemical investments in China at the time of construction. The refrigeration packages for this unit required coordination with SEI’s overall plant design to ensure seamless integration with the HDPE reactor loop and utility systems.
Challenges and Engineering Requirements
Process Temperature Control in petrochemical processing
Hengli Petrochemical required precise low-temperature cooling for Brine Chiller Package × 3 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 Propylene (R1270) 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 SEI (Sinopec Engineering Incorporation) 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 Hengli Petrochemical 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 Hengli Petrochemical and similar clients in the petrochemical processing sector, demonstrating consistent quality and on-time delivery performance across multiple projects.
Technical Scope and Specifications
The three brine chiller packages provide solvent cooling for the HDPE reactor loop. Each unit operates at a dual duty point of 1,034 kW and 2,200 kW to accommodate varying production rates and seasonal ambient conditions. The propylene (R1270) refrigerant circuit uses screw compressors driven by 560 kW and 630 kW motors.
The process-side coolant — a mixture of n-hexane and iso-hexane — is a flammable hydrocarbon solvent, requiring the entire package to comply with hazardous area classification standards. All electrical components, instrumentation, and control systems are rated for Zone 1 or Zone 2 explosive atmosphere classification. The combination of flammable refrigerant (R1270) and flammable coolant (hexane isomers) demands rigorous leak-tightness standards on all brazed, welded, and flanged connections.
Each package is delivered as a factory-assembled, pre-piped, and pre-wired skid to minimize field installation time and reduce on-site hot work in the hazardous area.
Delivery and Quality Assurance
All three packages underwent factory acceptance testing (FAT) at Lmart’s Zhangjiagang facility, including hydrostatic pressure testing of all pressure-containing components, electrical continuity and insulation resistance verification, and vibration checks during compressor run testing. Each package was shipped as a complete skid-mounted unit to the Changxing Island site in Dalian via overland transport.
The HDPE brine chiller project was the first of three concurrent orders from Hengli Petrochemical’s integrated complex, delivered alongside the ethylene tank farm direct cooling system and the PP brine chiller. Coordinating delivery of multiple packages for a single mega-project demonstrates Lmart’s production capacity and project management capability for large petrochemical clients.
Results and Business Impact
Lmart successfully delivered 3 units of Brine Chiller Package × 3 to Hengli Petrochemical, 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.
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Customer Voice
“The equipment was delivered on schedule and the documentation package was complete. The quality of fabrication met our inspection requirements.”
— Hengli Petrochemical project team (paraphrased from project review)
Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.