Basic Design. The selection of the heat exchanger design and materials shall give consideration to thermal and chemical performance (including the effects of scaling), pressure loss, corrosion, leak tightness, flow induced vibration and ease of maintenance. Only new materials shall be used. The heat exchangers shall be shell and tube type, with Geothermal Fluid in the tubes. A U-tube bundle will not be accepted. The internal diameters of the tubes shall be of sufficient size to allow easy mechanical cleaning including cleaning by high pressure water blasting. The precipitation of silica has been found to be dependent on the rate of temperature change. Therefore, the Geothermal Fluid transition time shall be minimised within the constraints of normal design practices. A Geothermal Fluid transition time (from 127(degree)C to exit at design flow) of more than 67 seconds shall only be permitted with prior approval of the Owner.
Basic Design. The selection of the condensers design and materials shall give consideration to the Site conditions described elsewhere in this Specification, particularly; seismic activities, noise levels, corrosion (H2S), leak tightness and ease of maintenance. Fan motor mountings shall be of sufficient rigidity to facilitate easy adjustment and prevent misalignment of the fan drive mechanism. Fans, fan motors and the drive mechanism shall not be subjected to or affected by ingress of rainwater or contaminants. The following is required: o Noise data sheets are required. o Fan performance curves are required. o Welding procedures and qualifications are required. o All heat exchangers shall undergo a sensitive leak test as described in the Boiler & Pressure Vessel Code Section V, Article 10, or by another method demonstrated to have equal sensitivity.
Basic Design. All necessary precautionary considerations for the expected hazardous fluid(s) shall be included in the design. Factors to be considered include: o Leakage o Possibility to isolate various parts of the system in the event of a fire o Venting to a safe area o Access to valves and other equipment in the event of a fire o Minimal binary working fluid loss during maintenance. o Material selection o Containment of spillage o Cleaning and flushing A minimum corrosion allowance of 3 mm shall apply for all carbon steel piping unless otherwise specified. Piping systems shall be arranged, wherever possible, with a fall of 1 in 40 towards the mains where drainage points are positioned taking into account the effect of cold springing where necessary. Where this cannot be attained the fall shall be the maximum possible and in any event an adequate fall for drainage must be maintained under all conditions of service. Drainage falls shall preferably be in the direction of flow. Drain points, complete with isolating valve, shall be provided at the lowest positions on all piping systems to facilitate emptying. Such drain connections are to be piped to waste or to a suitable collection point. Air release connections complete with isolating valves shall be positioned at the highest points on all main lines to enable trapped air to be expelled. Such connections shall be piped to the nearest drain or collection system. Buried pipe is not permitted for flammable substances. All piping shall be routed to provide a neat layout having the shortest possible run and requiring the minimum number of fittings. Piping shall be arranged so that full access is provided for the maintenance of equipment, and that removal or replacement of equipment can be achieved with the minimum dismantling of piping.
Basic Design. The second stage of ConceptSHIP, the basic design, starts with the creation of a hull form complying with the main characteristics and form coefficients from the conceptual study. The hull form is described by a set of cross-sections, each defined by a number of points (polylines) (Figure 9).
