Sr. Heat Exchanger Engineer

Role Overview

We're looking for a Sr. Heat Exchanger Engineer to own the design, specification, and development of the compact heat exchangers at the heart of Arbor's supercritical CO power system-the high- and low-temperature recuperators that set plant efficiency, and the coolers around them.

You'll lead technical engagement with our heat exchanger suppliers, develop and test additively manufactured and diffusion-bonded designs in high-temperature nickel alloys, and own the thermal and mechanical case for the hardware we put into service. You'll work closely with cycle analysts, mechanical and pressure vessel engineers, manufacturing, and test engineers in a fast-paced, hands-on R&D environment.

This is a rare opportunity to apply deep thermal-fluids and manufacturing expertise to climate-impactful technology at the frontier of power generation.

A power-industry background is not required. Engineers who have designed, built, and tested high-performance thermal hardware in aerospace, propulsion, or advanced manufacturing are encouraged to apply.

This is an onsite opportunity in our El Segundo, CA office.

Responsibilities

• Own the thermal-hydraulic design of compact heat exchangers across the Arbor power system-high- and low-temperature recuperators, precoolers, and heaters-from conceptual sizing through detailed design, balancing effectiveness, pressure drop, mass, and cost.
• Serve as technical lead with suppliers of advanced compact heat exchangers, including additively manufactured and printed circuit (diffusion-bonded) units: define requirements and specifications, lead design reviews, and own qualification and acceptance testing.
• Lead in-house design and development of additively manufactured heat exchangers in high-temperature nickel alloys (e.g., Inconel 625, Haynes 282), applying design for additive manufacturing (DfAM) to channels, headers, and manifolds.
• Plan and run print and flow trials-from coupons through subscale cores-to characterize geometry, surface finish, and process effects, and anchor thermal-hydraulic and pressure drop models to the data.
• Own the thermal-mechanical life case for high-temperature heat exchangers-pressure containment, thermal transients, creep, and fatigue-working with mechanical and pressure vessel engineers on ASME code compliance.
• Plan and execute thermal and hydraulic performance testing on development and plant hardware: define instrumentation, write test procedures, lead data reduction, and close the loop between test results and design.
• Specify and technically manage conventional heat exchangers (shell-and-tube, air-cooled) per TEMA and API 661 as balance-of-plant needs arise.
• Generate and maintain the full engineering documentation package: thermal and mechanical calculation packages, drawings, material and process specifications, and test reports.

Requirements

• Bachelor's degree in Mechanical, Chemical, Aerospace, or related Engineering field.
• 6+ years of experience designing, building, and testing high-performance thermal-fluid hardware-heat exchangers, recuperators, precoolers, regeneratively cooled components, or similar.
• Demonstrated thermal-hydraulic design of compact heat transfer hardware-additively manufactured, printed circuit, plate-fin, microchannel, or regeneratively cooled-including channel geometry selection for performance, pressure drop, and manufacturability.
• Hands-on manufacturing experience with processes that form internal flow passages-metal additive manufacturing (laser powder bed fusion or similar), vacuum brazing, or diffusion bonding-including process troubleshooting, inspection, and defect disposition.
• Track record of taking full-scale hardware-flight, production, or industrial-from design through fabrication and test, and using test data to correct your models and designs.
• Ability to build first-principles thermal-hydraulic models (e.g., segmental -NTU with variable fluid properties) in Python, MATLAB, or similar.
• Working knowledge of pressure-containing and elevated-temperature structural design-thermal stress, creep, and fatigue-sufficient to drive a life assessment with support from specialists.
• Track record of making consequential technical decisions with incomplete information, owning the outcome, and moving fast in a small team.

Preferred Qualifications

• Experience with supercritical CO or other supercritical or dense-phase fluids, including cryogenic propellants.
• Experience designing or qualifying printed circuit or other diffusion-bonded heat exchangers.
• Experience qualifying AM parameter sets, HIP and heat treatment, and powder removal for parts with internal passages.
• Experience specifying conventional heat exchangers per TEMA and API 661; proficiency with HTRI or equivalent.
• Familiarity with ASME Boiler and Pressure Vessel Code Section VIII as applied to heat exchangers.
• Background in startup, aerospace, or first-of-a-kind hardware development environments.

Benefits & Compensation

• Pre-IPO stock options
• Medical, dental, and vision insurance (Arbor covers 90% for employees)
• Basic life insurance fully covered
• Health savings account (HSA) with matching
• Flexible savings account (FSA)
• Unlimited PTO
• 12+ company holidays, including Earth Day!
• 401(k)
• Commuter benefits
• Annual learning and development stipend
• And more!

Base Pay

$165,000 - $180,000 USD/year. The salary is subject to the applicant's skills, qualifications, experience, and geographic location.