7 Refrigeration Packages for Hengli Petrochemical Dalian: Multi-Plant Coverage from PP to HDPE to Ethylene Tank Farm with R1270 Propylene Refrigerant

Lmart delivered seven refrigeration packages to Hengli Petrochemical’s Changxing Island complex in Dalian between 2018 and 2021 — spanning PP brine chilling, HDPE brine chilling with n-hexane/iso-hexane coolant, ethylene tank farm direct cooling, and C9 separation brine chilling. All units use R1270 (propylene) refrigerant, and the HDPE brine chillers feature a specialized hydrocarbon coolant circuit engineered for the PE slurry loop process.

Customer	Hengli Petrochemical (Dalian) Co., Ltd. (恒力石化（大连）有限公司)
Industry	Integrated refining & petrochemicals
Project Location	Changxing Island, Dalian, Liaoning, China
Equipment	Brine chillers × 6, Direct cooling unit × 1 (7 units total)
Capacity Range	460 kW to 2,200 kW
Refrigerant	R1270 (propylene) — all units
Design Institutes	SEI, Yangzi Petrochemical Research Institute, Nanjing Jinling
Applications	PP, HDPE, ethylene tank farm, C9 separation
Delivery Period	2018–2021

Customer Background and Industry Context

Hengli Petrochemical is one of China’s largest privately owned integrated refining and petrochemical companies and a subsidiary of Hengli Group — a Fortune Global 500 conglomerate. The Changxing Island complex in Dalian, Liaoning Province, is the company’s flagship production base, with a crude oil processing capacity of 20 million tonnes per year. The complex produces a full downstream product chain: polypropylene (PP), high-density polyethylene (HDPE), purified terephthalic acid (PTA), polyester fiber, and C9/C5 aromatics fractions.

The Changxing Island complex was built in a single integrated phase — an unusual approach that required all process units and their supporting utilities, including refrigeration systems, to be engineered, procured, and commissioned on an accelerated timeline. For refrigeration package suppliers, this meant delivering multiple units for different process plants simultaneously, with minimal margin for schedule delays.

Hengli’s procurement model combines in-house project management with engineering designs from multiple design institutes — SEI (Sinopec Engineering Inc.) for the PP and HDPE plants, Yangzi Petrochemical Research Institute for the ethylene tank farm, and Nanjing Jinling for the C9 separation unit. This multi-institute structure required Lmart to coordinate technical submittals and design reviews with three separate engineering organizations, each with its own specifications, drawing standards, and approval workflows.

Challenges and Engineering Pain Points

HDPE Brine Chillers with n-Hexane/Iso-Hexane Coolant

The most technically demanding units in this project are the three HDPE brine chillers. Unlike conventional brine chillers that cool ethylene glycol, these units cool a mixture of n-hexane and iso-hexane — the diluent solvent used in the HDPE slurry loop polymerization process. Hexane is a flammable hydrocarbon (flash point −22 °C), which means both the refrigerant side (R1270 propylene) and the coolant side of these chillers handle flammable fluids. This double-flammable configuration requires exceptional attention to mechanical seal integrity, gasket material selection, electrical area classification, and emergency response planning. The evaporator must be designed for hexane’s thermophysical properties — lower viscosity and higher thermal conductivity than ethylene glycol, but with different fouling characteristics and a narrower acceptable temperature range to prevent hexane vaporization in the evaporator tubes.

Dual-Capacity HDPE Units: 1,034/2,200 kW

The HDPE brine chillers are specified with dual capacity ratings — 1,034 kW and 2,200 kW — reflecting two distinct operating modes in the HDPE slurry process. The lower capacity corresponds to normal polymerization conditions, while the higher capacity handles peak cooling loads during reactor transitions, grade changes, or upset recovery. The compressor system must provide stable operation across this 2:1 turndown range, with smooth capacity modulation to avoid thermal shock to the hexane coolant circuit. Motor sizing at 560 kW and 630 kW for the two compressor stages accommodates the higher capacity while maintaining efficiency at the lower operating point.

Ethylene Tank Farm Direct Cooling at 1,000 kW Motor Power

The ethylene tank farm direct cooling unit operates with a 1,000 kW motor driving a 1,200 kW cooling duty — a ratio that reflects the thermodynamic challenge of cooling ethylene at temperatures approaching its boiling point (−103.7 °C at atmospheric pressure). While this unit does not operate at cryogenic temperatures, it must maintain ethylene below its critical storage temperature to prevent excessive boil-off from the tank farm. The R1270 refrigerant provides direct cooling without an intermediate brine loop, which improves heat transfer efficiency but requires the evaporator to handle ethylene directly — a flammable, asphyxiant gas that demands leak-tight construction and comprehensive safety instrumentation.

Multi-Institute Design Coordination

Three design institutes specified the seven units using different drawing standards, nozzle orientation conventions, and technical specification formats. SEI’s PP and HDPE specifications followed Sinopec corporate standards; Yangzi Petrochemical Research Institute used its own technical specification template for the ethylene tank farm; and Nanjing Jinling applied yet another documentation framework for the C9 separation unit. Lmart’s engineering team maintained separate submittal packages for each institute while ensuring that the underlying equipment design principles — compressor platform, control system architecture, safety instrumentation philosophy — remained consistent across all seven units for maintainability and spare parts commonality.

Why Hengli Petrochemical Selected Lmart

R1270 propylene refrigerant specialization. All seven units use R1270, and the HDPE units additionally handle flammable hexane coolant. Lmart’s extensive track record with propylene refrigerant systems — including units for Zhejiang Petrochemical, Satellite Petrochemical, and other major petrochemical customers — provided the safety engineering pedigree that Hengli’s project team required for a complex with multiple flammable-service refrigeration packages operating simultaneously.

Multi-unit delivery capability. Hengli’s accelerated construction schedule required all 2018 units to be delivered within the same window. Lmart’s workshop capacity — with multiple assembly bays and dedicated test facilities — enabled parallel production of five units (PP, HDPE × 3, ethylene tank farm) without quality compromises or schedule conflicts.

Hydrocarbon coolant experience. The n-hexane/iso-hexane coolant specification for the HDPE chillers is uncommon in the Chinese market, where most brine chillers are designed for ethylene glycol service. Lmart’s experience with non-standard coolants — including direct ethylene cooling, propane cooling, and hydrocarbon solvent cooling — made it one of few qualified suppliers for this application.

Repeat order from C9 separation (2021). The 2021 order for two C9 separation brine chillers came three years after the initial 2018 delivery, confirming that the original five units had performed reliably through multiple years of continuous operation. The C9 units were designed by Nanjing Jinling — a different institute from the 2018 units — demonstrating that Lmart’s reputation within the Hengli organization was strong enough to secure orders from new design institute partners.

Engineering and Manufacturing Solution

The seven units were engineered as four distinct package configurations, each tailored to the specific process requirements of its target plant.

PP brine chiller (1,200 kW × 1). A conventional ethylene glycol brine chiller for the polypropylene plant, designed to SEI specifications. The 450 kW motor and R1270 refrigerant provide efficient cooling at the moderate evaporating temperatures required for PP process cooling. This unit represents the most straightforward configuration in the project — a proven design that Lmart has delivered in large quantities to PP plants across China.

HDPE brine chillers (1,034/2,200 kW × 3). The project’s most technically complex units. Each chiller circulates n-hexane/iso-hexane through a flooded shell-and-tube evaporator with R1270 on the shell side. The dual-capacity rating requires a two-compressor arrangement with independent loading control, allowing each compressor to be loaded or unloaded independently to match the instantaneous cooling demand from the HDPE slurry loop. The evaporator tube bundle uses enhanced-surface tubes optimized for hexane’s heat transfer characteristics, with tube-side velocities calculated to prevent hexane vaporization at design pressure drop. All flanged connections use spiral-wound gaskets rated for hydrocarbon service, and the complete package is installed within a classified hazardous area with continuous gas detection monitoring on both the refrigerant and coolant sides.

Ethylene tank farm direct cooling (1,200 kW × 1). This unit provides direct refrigeration cooling to the ethylene storage tank farm, maintaining tank temperatures below the maximum allowable storage temperature to control boil-off losses. The R1270 refrigerant circuit cools ethylene directly through a dedicated heat exchanger without an intermediate brine loop, maximizing thermal efficiency. The 1,000 kW motor reflects the challenging thermodynamic conditions of cooling a light hydrocarbon at near-cryogenic temperatures. This unit was designed by Yangzi Petrochemical Research Institute, which specified a control system architecture optimized for integration with the tank farm’s existing DCS and emergency shutdown system.

C9 separation brine chillers (460 kW × 2). Ordered in 2021, these smaller-capacity units cool ethylene glycol brine for the C9 aromatics separation process, where controlled low temperatures are required to crystallize and separate specific C9 fraction components. Designed by Nanjing Jinling, these units use a single-compressor configuration with 250 kW motors and R1270 refrigerant. Despite their relatively modest capacity, the C9 separation application requires precise temperature control (±0.5 °C) to maintain product quality during the crystallization process.

Delivery Summary

#	Year	Plant / Application	Type	Capacity	Motor Power	Refrigerant	Coolant	Qty
1	2018	PP	Brine chiller	1,200 kW	450 kW	R1270	Ethylene glycol	1
2	2018	HDPE	Brine chiller	1,034/2,200 kW	560/630 kW	R1270	n-Hexane / iso-hexane	3
3	2018	Ethylene tank farm	Direct cooling	1,200 kW	1,000 kW	R1270	Ethylene	1
4	2021	C9 separation	Brine chiller	460 kW	250 kW	R1270	Ethylene glycol	2

Total installed cooling capacity: 9,754 kW across 7 units serving 4 process plants.

n-Hexane/Iso-Hexane vs. Ethylene Glycol as Coolant

Property	n-Hexane / Iso-Hexane	Ethylene Glycol (50%)
Flash Point	−22 °C (flammable)	111 °C (non-flammable in service)
Thermal Conductivity	~0.12 W/m·K	~0.38 W/m·K
Viscosity at 0 °C	~0.4 mPa·s (very low)	~5.0 mPa·s
Specific Heat	~2.3 kJ/kg·K	~3.3 kJ/kg·K
Pump Power Requirement	Lower (low viscosity)	Higher (high viscosity at low temp)
Safety Classification	Hazardous area required	Non-hazardous
Typical Application	HDPE/LLDPE slurry loop diluent cooling	General process brine cooling

The choice of n-hexane/iso-hexane as coolant is not optional — it is dictated by the HDPE slurry loop process, where hexane serves as both the polymerization diluent and the heat transfer medium. The chiller must cool hexane returning from the reactor loop before it is recirculated. Using ethylene glycol would require an additional heat exchanger between the glycol loop and the hexane process loop, adding capital cost, thermal resistance, and maintenance complexity. Direct hexane cooling in the chiller evaporator eliminates this intermediate step but demands a manufacturer with proven capability in flammable-coolant refrigeration system design.

Project Execution, Quality Control, and Delivery

The 2018 order for five units was executed under Hengli’s fast-track construction schedule, with all units required for delivery within a compressed timeline to match the integrated complex’s commissioning sequence. Lmart allocated dedicated project engineering and workshop resources to ensure parallel fabrication of the five 2018 units.

Key QC milestones for each unit:

• Compressor performance verification against process data sheets from SEI (PP/HDPE) and Yangzi Petrochemical Research Institute (ethylene tank farm)
• Evaporator and condenser fabrication with material certification, dimensional inspection, and tube expansion/welding quality verification
• HDPE units: special attention to evaporator tube-side cleanliness for hexane service — no residual oils, grinding debris, or weld spatter that could contaminate the hexane circuit
• Piping fabrication for dual-flammable service (R1270 + hexane) with 100% radiographic examination of butt welds and leak testing at 1.5× design pressure
• Electrical and instrumentation installation with ATEX zone verification — Zone 1 classification for HDPE units due to hexane coolant
• Factory acceptance test with compressor run-in, vibration measurement, and safety system functional testing
• Protective packaging for sea transport from Zhangjiagang to Dalian port, followed by road transport to the Changxing Island site

The 2018 units were transported from Lmart’s Zhangjiagang facility to Dalian’s Changxing Island via a combination of river barge and coastal shipping — approximately 1,200 km by sea — with final road transport from Dalian port to the plant site. Marine transport packaging included VCI (vapor corrosion inhibitor) wrapping for all exposed machined surfaces and desiccant packs within the sealed refrigerant circuit to prevent moisture ingress during the multi-day transit.

Results and Business Impact

Seven units totalling 9,754 kW of installed cooling capacity were delivered across four process plants within the Changxing Island complex. The five 2018 units were commissioned during the complex’s initial start-up phase, and all units have operated continuously since commissioning — a critical requirement for a mega-complex where refrigeration system downtime directly impacts production throughput across multiple downstream plants.

The HDPE brine chillers with n-hexane/iso-hexane coolant represent a specialized capability that few Chinese refrigeration package manufacturers can offer. This reference has directly supported Lmart’s qualification for HDPE refrigeration projects at other major PE producers, where the hexane coolant requirement immediately narrows the qualified supplier field.

The 2021 follow-on order for C9 separation brine chillers — from a new design institute (Nanjing Jinling) and for a different process application — demonstrates that Lmart’s reputation within Hengli extends beyond the original procurement team. When a new design institute specifies refrigeration for a Hengli project, Lmart is included in the bid list based on demonstrated performance at the same site.

For Lmart, the Hengli account validates the multi-plant, multi-institute supply model that is increasingly common at China’s mega petrochemical complexes. The ability to deliver different package configurations to different design institute specifications, all for the same end customer and the same site, is a competitive differentiator in a market where integrated refining-petrochemical complexes are the dominant growth driver.

Customer Voice

Hengli Petrochemical’s decision to return for additional units three years after the initial delivery — from a different design institute and for a different process — is the strongest form of customer endorsement in the petrochemical equipment market.

“The HDPE chillers have run continuously since start-up. The hexane circuit has been leak-free, and the dual-capacity control responds well to reactor load changes.”

— Hengli Petrochemical plant operations team (paraphrased from maintenance review)

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