Power generation requires instant heat to melt ice

Introduction:

As new power generation sources continue to move from the laboratory to the testing arena it has become crucial to deal with the real world issues such as operating in freezing climates. Often there are unprotected water loops that do not utilize additives to prevent freeze. This has made design and management of the thermal subsystems within some power generation devices an important key in bringing new technologies to full scale commercialization.

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Customer Challenge:

A power generation product development requiring a de-ionized water loop was being subjected to freeze-thaw tests. Two major issues plagued the developer. The first was preventing damage to the components and piping of the system during hard freeze. This risk was somewhat mitigated by the customer's decision to drain the entire DI water loop into one vessel during shutdown. However, the freeze/thaw vessel itself would have to withstand the mechanical forces associated with repeated hard freeze and thaw cycles in addition to addressing other issues such as degasification associated with the DI water loop. The second issue was getting the entire DI water loop thawed and flowing again in as little time as possible while consuming as little power as possible. To further complicate matters, other aspects of the development were already well ahead of the thermal considerations making the development not only challenging from a technical feasibility perspective but also from a schedule perspective.

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Single Iteration Solution:

Single Iteration provides expertise in thermal systems required to meet challenging thermal feasibility requirements as well as the program management expertise to meet challenging schedule requirements. Through an expedited discovery process conducted at the customer's facility, Single Iteration was able to prepare a development specification for the freeze thaw vessel that established clear development requirements. A multitude of concepts using a wide variety of materials, heating technologies, and configurations were then generated against the specification. These concepts were compared using standard cost-benefit analysis techniques to determine which concepts provided the lowest risk with respect to performance, cost, and schedule. In parallel with concept generation and evaluation, numerical analyses were also completed to determine the power curves for melting given ice masses; as well as, the mechanical forces generated during ice freezing within given geometries. As the best concepts began to rise to the surface these analyses were then customized to simulate as closely as possible the actual design concepts in order to determine optimized vessel material, geometry and power distribution.

The results of the final analysis were fed directly into design to rapidly produce a working prototype. Because the analysis had created boundaries for vessel, fin material and geometry based on established design rules for fabrication, designs could be easily evaluated for manufacturability. Due to the aggressive schedule a number of manufacturing approaches that required complex tooling simply would not fit within the given timeline. Single Iteration tools quickly allowed identification of a design solution capable of being fabricated in the required time frame.

Under Single Iteration program management rapid prototypes were manufactured using a combination of Single Iteration and Watlow rapid prototyping resources in addition to outside suppliers of both components and services. A formal test plan was followed to minimize integration risk in the delivered system. Prototypes were built, tested to plan, and delivered within four (4) weeks of verbal approval to build. On site integration and testing validated the design against the theoretical test results and saved the customer thousands of dollars and months of schedule time over their original plan for doing the vessel design in-house.

Through this development, Single Iteration enabled the customer to dramatically reduce the space required to house their thermal subsystem while increasing overall system performance at the same time.