Design and Fabrication of an Experimental Facility for High-Pressure Pool Boiling

In this work, we present the design and fabrication a high-pressure pool boiling facility to conduct pool boiling experiments on horizontal heated surfaces under elevated pressures, up to 20 bar. Previous research has shown that micro- and/or nano-structured surfaces and coated surfaces will increase heat transfer coefficients up to one order of magnitude at atmospheric pressure. However, most boiling applications are subjected to high pressure, especially in the power industry. Pressure inside a boiling water reactor in a nuclear power plant will reach as high as 75 atm (75.99 bar). In order to determine how heat transfer is enhanced at increased pressures, with deionized water and refrigerants, on modified surfaces, a special experimental setup needs to be designed and fabricated. Difficulties in making such an experimental setup come from stabilizing the system pressure, sealing the test setup and visualizing the boiling conditions in the vessel. Both advantages and disadvantages of this design will be discussed and possible methods for improvements will be proposed. Preliminary test results on a plane copper surface are also included. Future research will be focusing on boiling of water and refrigerants on micro-structured copper surfaces, graphene coated, and Teflon© coated surfaces under high pressure.