Energy characteristics of medium pressure steam boilers

The object of this study is the thermal and energy characteristics of medium pressure boilers of СНPP-1, four boilers CKTI-75/39F-2-4 and two boilers TP-150-2. All boilers operate on a common steam collector of 32 atm, at 420°С. Fuel is a mixture of blast furnace gas and natural gas in the ratio of 0.7-0.9 volume particles. The characteristics of the blast furnace gas are not constant: the elemental composition, humidity, and dustiness of blast furnace gas change significantly. Analysis of operation of CHPP-1 medium pressure boilers of OJSC "Mariupol Metallurgical Combinat named after P. G. Ilyich" was carried out on the basis of the technical documentation and materials obtained during the ecological and thermal-technical tests of the boilers CKTI-75/39F-2-4 No. 7–9, and TP-150 No. 11, 12 of SU "Promavtomatika". The main purpose of the analysis is to identify patterns that affect the operational characteristics of boilers, especially the efficiency. The analysis revealed the nature of the overall dependence of the efficiency on the load, as well as the dependence of the efficiency of the boilers on the load at different thermal parts of the blast furnace gas. After carrying out the balance tests, the dependencies of the exhaust gas temperature on the boiler load at different thermal parts of the blast furnace gas were established

Vanishing Theorems and String Backgrounds

We show various vanishing theorems for the cohomology groups of compact hermitian manifolds for which the Bismut connection has (restricted) holonomy contained in SU(n) and classify all such manifolds of dimension four. In this way we provide necessary conditions for the existence of such structures on hermitian manifolds. Then we apply our results to solutions of the string equations and show that such solutions admit various cohomological restrictions like for example that under certain natural assumptions the plurigenera vanish. We also find that under some assumptions the string equations are equivalent to the condition that a certain vector is parallel with respect to the Bismut connection.Comment: 25 pages, Late

Design of a Helium Passivation System for the Target Vessel of the Beam Dump Facility at CERN

The Beam Dump Facility (BDF) is a proposed general-purpose facility at CERN, dedicated to fixed target and beam dump experiments, currently being developed in the context of the Physics Beyond Colliders program. The design of the facility will allow to host different types of experiments, of which SHiP is planned to be the initial one. The core of the facility is a high-density target/dump absorbing the full intensity of the SPS beam and generating a cascade of particles that are detected downstream the target complex. The target and its shielding blocks are positioned inside a vessel, which is planned to be passivized with helium, in order to reduce the activation of the gas surrounding the target and to extend the operational life of materials and equipment. The passivation system that will be in charge of purifying and circulating the helium is a critical component for the operation of the facility. Fluid dynamics simulations have been performed to study the circulation of the helium through the vessel. A detailed design of the helium passivation system and its main components has been developed