Multimegawatt Electrolyzer Stack Heat Exchangers

This document outlines the technical specifications for purchasing five heat exchangers for the Multimegawatt (MMW) Electrolyzer project, aiming to create a test platform for new electrolyzers. These heat exchangers will cool electrolyzer stacks, using 50/50 propylene glycol/water on the cold side and Type 1 DI water on the hot side, with the DI water side requiring cleaning and passivation. Key requirements include ASME stamping, operational temperatures up to 200°F (93°C), and specific maximum working pressures for each fluid (100 psi for glycol, 150 psi for DI water), with a pressure drop less than 15 psi. Three heat exchangers (HX-1, 2, 3) must reject over 1 MW, while two (HX-4, 5) must reject over 1.5 MW, each with specified glycol and DI water flow rates and inlet temperatures. Installation will be handled by the research group, with no subcontracting for installation.

The National Renewable Energy Laboratory (NREL) has issued Request for Quotes (RFQ) Number 2025025474 for

This document outlines the specifications for “Electrolyzer Stack Heat Exchangers” for the new Flatirons hydrogen facility. The objective is to procure five plate-type heat exchangers that will remove heat from deionized water used by electrolysis stacks. Key specifications include compatibility with Type I deionized water (hot side) and a 50/50 water/propylene glycol mixture with corrosion inhibitor (cold side), both with a maximum operational temperature of 200°F (93°C). The HXs must be free of sulfur-containing components on the hot side, designed to ASME pressure codes, passivated according to ASTM A967, and feature ANSI flanged fittings. Delivery to the NREL Flatirons Campus and design for a 6,040 ft altitude are required. Three HXs (1, 2, & 3) must reject >1 MW of heat, with cold-side MAWP at 100 psi and hot-side MAWP at 150 psi. Two HXs (4 & 5) must reject >1.5 MW, with similar pressure ratings. NREL will provide a climate-controlled enclosure.

Amendment No. 1 to Request for Quote (RFQ) Number 2025025474 for Multimegawatt Electrolyzer Stack Heat Exchangers addresses various questions from potential offerors. Key clarifications include accepting lead times with delivery by May 2026, confirming that lead time is not the deciding factor, and allowing the use of standard water properties for DI water calculations. The amendment specifies that all wetted hot-side components of the heat exchangers must be passivated or cleaned for Type I DI water service, and studded ports are acceptable. Hydrostatic pressure tests can use clean water. Preferred gasket material is FKM, and surface finish requirements for the hot side are driven by passivation needs, while the cold side can use standard industrial finishes. Outlet temperatures are to be calculated based on the provided flow rates, inlet temperatures, and minimum heat rejection capacity. Proposals are due by September 25, 2025, at 5:00 PM Pacific Standard Time, and offerors must confirm receipt and acceptance of this amendment.