7 Industrial Refrigeration Packages for Sinopec Zhenhai Refining & Chemical: Including China’s Largest 23,300 kW Acrylonitrile Brine Chiller

Lmart delivered seven refrigeration and direct cooling packages to Sinopec Zhenhai Refining & Chemical Company between 2020 and 2022 — spanning HDPE direct cooling, acrylonitrile brine chillers, PDH refrigeration, solvent/BOG recovery, and general-purpose brine chillers. The centrepiece is a pair of 23,300 kW acrylonitrile brine chillers using propylene refrigerant — the largest single-unit refrigeration packages Lmart has ever delivered.

Customer	Sinopec Zhenhai Refining & Chemical Company (中国石化镇海炼化)
Industry	Petroleum refining & petrochemicals
Project Location	Zhenhai District, Ningbo, Zhejiang, China
Equipment	Brine chillers × 6, Direct cooling unit × 1 (7 units total)
Capacity Range	175 kW to 23,300 kW
Refrigerants	Propylene (process-sourced), R1270
Design Institutes	SEI (Sinopec Engineering Inc.), Sinopec in-house
Applications	HDPE, acrylonitrile, PDH, solvent/BOG recovery
Delivery Period	2020–2022

Customer Background and Industry Context

Sinopec Zhenhai Refining & Chemical Company is one of China’s top three refining complexes and a core subsidiary of China Petrochemical Corporation (Sinopec Group) — the world’s largest refining company by throughput. Located in Zhenhai District, Ningbo, the complex processes approximately 23 million tonnes of crude oil per year and produces a full spectrum of refined products and petrochemicals including gasoline, diesel, jet fuel, ethylene, propylene, acrylonitrile, HDPE, and polypropylene.

Zhenhai’s continuous expansion into high-value downstream petrochemicals — particularly acrylonitrile (a precursor to acrylic fibers, ABS plastics, and nitrile rubber) and propane dehydrogenation (PDH) for on-purpose propylene production — has driven demand for large-capacity industrial refrigeration systems. These processes require precise temperature control at cryogenic and sub-zero conditions, with cooling capacities that push the limits of single-unit compressor package design.

As a Sinopec subsidiary, Zhenhai’s procurement follows rigorous vendor qualification requirements including Sinopec’s centralized supplier registry, mandatory design review by Sinopec Engineering Inc. (SEI), and third-party inspection at every manufacturing milestone. Qualifying as an approved refrigeration package supplier to Sinopec represents one of the highest barriers to entry in China’s industrial refrigeration market.

Challenges and Engineering Pain Points

23,300 kW Single-Unit Capacity: Pushing Compressor Package Limits

The acrylonitrile brine chiller at 23,300 kW is an extraordinary cooling capacity for a packaged refrigeration unit. At this scale, every aspect of the system is at or near the upper boundary of standard industrial practice: screw compressor displacement, evaporator surface area, condenser heat rejection, oil separation efficiency, and the structural integrity of the package skid itself. The propylene refrigerant circuit must handle mass flow rates that require careful attention to piping diameter, pressure drop, and liquid distribution across the evaporator tubes. Two-stage compression with economizer is essential to maintain acceptable discharge temperatures and coefficient of performance (COP) at the −35 °C to −40 °C evaporating temperatures typical of acrylonitrile process cooling.

Process-Sourced Propylene as Refrigerant

All 2022 units use propylene (C&sub3;H&sub6;) as refrigerant rather than conventional synthetic refrigerants like R507A or R134a. This is a deliberate engineering choice: Zhenhai produces propylene on-site in its PDH and FCC units, so the refrigerant is available at no marginal cost and eliminates supply chain dependency on specialty refrigerant vendors. However, propylene is a flammable hydrocarbon (ASHRAE Group A3), which imposes strict requirements on electrical classification, ventilation, gas detection, emergency shutdown logic, and mechanical seal integrity. Every component in the refrigerant circuit — compressors, vessels, valves, instruments — must be rated for flammable service with appropriate ATEX/IECEx zone classifications.

PDH Refrigeration at −32 °C

The 8,330 kW PDH refrigeration system operates at −32 °C evaporating temperature to condense propylene product from the PDH reactor effluent. At this temperature, propylene refrigerant is well below its normal boiling point (−47.6 °C), resulting in low suction pressure and high compression ratio. The system must maintain stable operation across variable load conditions as the PDH reactor cycles between different feed rates and catalyst regeneration phases. Turndown capability — the ability to operate efficiently at 50% or even 25% of design capacity — is critical for PDH service where reactor output is not constant.

Multi-Application Integration Across a Single Refining Complex

The seven units serve four distinct process plants within the Zhenhai complex: HDPE, acrylonitrile, PDH, and solvent/BOG recovery. Each application has different evaporating temperatures, cooling media (ethylene glycol brine vs. direct process gas cooling), control philosophies, and safety requirements. Lmart’s scope required adapting the base refrigeration package design to each application while maintaining commonality in compressor platforms, control systems, and spare parts — a logistics and engineering advantage for a single-site customer managing maintenance across multiple units.

Why Sinopec Zhenhai Selected Lmart

Proven large-capacity compressor package experience. The 23,300 kW acrylonitrile chiller required a manufacturer with demonstrated capability at the extreme end of packaged refrigeration capacity. Lmart’s reference list includes multiple units above 10,000 kW for other major petrochemical customers (Zhejiang Petrochemical, Shandong Yulong), establishing the track record necessary to pass Sinopec’s technical qualification review.

Propylene refrigerant expertise. Designing for propylene service is fundamentally different from conventional refrigerant systems. Lmart has delivered over 50 propylene-refrigerant packages across China’s petrochemical sector, with full in-house capability for flammable gas system design, ATEX-rated component specification, and SIL-rated safety instrumented systems.

SEI design coordination. Multiple units in this project were designed under Sinopec Engineering Inc. (SEI), one of China’s most demanding engineering procurement companies. Lmart’s engineering team has established working relationships with SEI across numerous projects, enabling efficient design review cycles and minimizing revision loops during the approval process.

Repeat order confidence. The 2020 HDPE direct cooling unit was the initial order. Its successful commissioning and stable operation led directly to the much larger 2022 order for five additional units — including the flagship 23,300 kW acrylonitrile chillers. This progression from a single 175 kW trial unit to a 23,300 kW flagship order is the strongest possible validation of equipment performance and supplier reliability.

Engineering and Manufacturing Solution

The seven units were engineered as application-specific packages, each optimized for its target process conditions while sharing common design principles for propylene/R1270 refrigerant service.

Acrylonitrile brine chillers (23,300 kW × 2). These are the project’s centrepiece — each unit cooling ethylene glycol brine from the acrylonitrile quench and absorption columns. The cooling duty requires two-stage screw compression with inter-stage economizer to achieve the required evaporating temperature while keeping discharge temperature within compressor limits. The evaporators are flooded shell-and-tube type with propylene on the shell side and ethylene glycol on the tube side, designed for high fouling resistance given the acrylonitrile process environment. Each unit includes a dedicated oil recovery system, liquid receiver, and PLC-based control panel with redundant safety instrumentation for propylene service.

PDH refrigeration system (8,330 kW × 1). This unit provides direct process cooling for the PDH product recovery section, condensing propylene product from the reactor effluent at −32 °C. Unlike the brine chillers, this is a direct refrigeration system where propylene refrigerant provides cooling without an intermediate brine loop. The system includes capacity modulation via slide valve control for load-following operation during reactor cycling.

Solvent/BOG refrigeration (1,500 kW × 1). This unit handles boil-off gas (BOG) recovery from solvent storage, re-condensing vapors that would otherwise be flared. The 1,400 kW motor power relative to 1,500 kW cooling capacity reflects the near-unity COP typical of BOG recovery applications where the evaporating temperature is close to ambient.

Brine chillers (6,100 kW × 2). General-purpose ethylene glycol brine chillers serving multiple process cooling demands across the refinery complex. These units use propylene refrigerant sourced from the adjacent PDH/FCC units, with 1,250 kW motors indicating efficient operation at moderate evaporating temperatures.

HDPE direct cooling (175 kW × 1). The 2020 unit — a compact direct cooling package for the HDPE plant, using R1270 refrigerant with a 132 kW motor. This was the entry point into the Zhenhai account, and its reliable performance over two years of continuous operation was instrumental in securing the 2022 orders.

Delivery Summary

#	Year	Plant / Application	Type	Capacity	Motor Power	Refrigerant	Coolant	Qty
1	2020	HDPE	Direct cooling	175 kW	132 kW	R1270	—	1
2	2022	Acrylonitrile	Brine chiller	23,300 kW	—	Propylene	Ethylene glycol	2
3	2022	PDH	Refrigeration system	8,330 kW @ −32 °C	—	Propylene	—	1
4	2022	Solvent/BOG recovery	Refrigeration system	1,500 kW	1,400 kW	Propylene	Solvent/BOG	1
5	2022	General process cooling	Brine chiller	6,100 kW	1,250 kW	Propylene	Ethylene glycol	2

Total installed cooling capacity: 68,505 kW across 7 units.

Propylene vs. Synthetic Refrigerants in Petrochemical Service

Property	Propylene (R1270)	R507A	R134a
GWP (AR5)	2	3,985	1,430
ODP	0	0	0
Boiling Point	−47.6 °C	−46.7 °C	−26.1 °C
Flammability	A3 (highly flammable)	A1 (non-flammable)	A1 (non-flammable)
Cost at Refinery	Near zero (process by-product)	Commercial purchase	Commercial purchase
COP at −35 °C	~2.8	~2.5	Not suitable
Typical Use	Petrochemical complexes with on-site propylene	Chemical plants, cold storage	Air conditioning, moderate-temp chilling

For a refinery producing propylene on-site, the choice is economically compelling: near-zero refrigerant cost, superior thermodynamic performance at low evaporating temperatures, and a GWP of 2 versus nearly 4,000 for R507A. The trade-off is the flammability classification, which requires purpose-built safety systems — a capability that differentiates specialized industrial refrigeration manufacturers like Lmart from general-purpose chiller suppliers.

Project Execution, Quality Control, and Delivery

Manufacturing followed Sinopec’s mandatory quality surveillance program, with hold points for third-party inspection at each critical stage. The Sinopec QA representative was present at the Lmart workshop for compressor performance testing, pressure vessel hydrostatic testing, electrical system verification, and final package inspection.

Key QC milestones for each unit:

• Compressor selection and performance curve verification against Sinopec/SEI process data sheets
• Pressure vessel fabrication (evaporators, condensers, receivers, oil separators) with material certification traceability and 100% radiographic examination of pressure-containing welds
• Skid structural analysis and fabrication — particularly critical for the 23,300 kW units where the combined weight of compressors, vessels, and piping on a single skid requires FEA-verified structural design
• Piping fabrication and installation with stress analysis for propylene service, including thermal expansion allowances for operation at −32 °C to −40 °C
• Electrical and instrumentation installation with ATEX/IECEx zone verification for propylene-rated equipment
• Nitrogen leak test and vacuum drying of the complete refrigerant circuit
• Factory acceptance test (FAT) with compressor run-in on propylene refrigerant, verifying capacity, power consumption, vibration, and safety system response
• Final dimensional survey, painting inspection, and preparation for oversize load transport

The 23,300 kW units required oversize load transport from Lmart’s Zhangjiagang facility to the Zhenhai complex in Ningbo — approximately 350 km by road. Transport planning included route survey for bridge clearances and turning radii, police escort coordination, and night-time travel restrictions. Each unit was shipped as a fully assembled skid-mounted package to minimize site installation work.

Results and Business Impact

Seven units totalling 68,505 kW of installed cooling capacity were delivered and commissioned across four process plants within the Zhenhai complex. The 23,300 kW acrylonitrile chillers remain the largest single-unit refrigeration packages in Lmart’s delivered reference list — a benchmark that demonstrates capability at the upper limit of packaged industrial refrigeration.

The progression from a single 175 kW HDPE direct cooling unit in 2020 to five major refrigeration packages in 2022 illustrates the typical supplier development path within Sinopec: a small initial order to evaluate manufacturing quality and project execution, followed by rapid scale-up once the supplier has proven reliability. For Lmart, the Zhenhai account now represents one of the most valuable reference relationships in the China petrochemical market — Sinopec approval opens doors to other Sinopec subsidiaries and to the broader network of EPC contractors that serve the Sinopec ecosystem.

The use of process-sourced propylene as refrigerant across all 2022 units reflects a broader industry trend: as refineries expand into downstream chemicals and produce propylene on-site, the economic case for propylene refrigerant becomes overwhelming. Lmart’s demonstrated capability in large-scale propylene refrigeration positions it to capture this growing market segment as more Chinese refineries follow the integrated refining-petrochemical model that Zhenhai exemplifies.

Customer Voice

Sinopec Zhenhai’s decision to expand from a single 175 kW trial unit to over 68,000 kW of installed refrigeration capacity within two years speaks directly to equipment performance and supplier execution quality.

“The 23,300 kW units met all performance guarantees during the acceptance test. The capacity, power consumption, and vibration levels were within specification.”

— Sinopec Zhenhai project engineering team (paraphrased from commissioning review)

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