| OCR Text |
Show 8 fuel, CP-grade methane (guaranteed 99 percent pure), is metered twice: with a rotameter for indication only, and with a Singer dry-gas meter and stopwatch for data reduction purposes. The dry-gas meter is also calibrated against an NBS-traceable flow meter. The air and fuel are then mixed, preheated and burned, and the combustion products cooled by the boiler and recuperator. The combustion-product temperature is measured at the recuperator exit to evaluate stack loss. Heat transfer to the boiler working fluid is measured with a calorimetry system to allow the burner system to be evaluated independent of the balance of the heat pump. Vertical condenser pipes attached to both ends of the boiler are enclosed in stainless-steel jackets through which pressurized hot water at roughly 240 F (390 K) flows. (Pressure limitations on the hot-water system preclude the use of higher-temperature water, which would have been desirable.) Calibrated type-K thermocouples at the calorimeter inlet and outlet are connected to provide a differential voltage which is displayed on a Systron-Donner Model 7362 microvoltmeter. Brooks high-pressure rotameters provide flow indication. Water flow rates for data reduction are measured by collecting the discharge flow in buckets for a known period of time and weighing with an Ohaus electronic scale. The masses are corrected for the nonzero quality of the discharge flow and the consequent loss of a modest amount of water vapor. Data reduction is straightforward and is largely completed during testing. The important indices of performance are as follows: t Energy input rate, calculated as the product of gas flow rate and higher-heating value; • Calorimeter energy extraction rate, calculated as the product of water flow rate and enthalpy increase for the two calorimeters; • System efficiency, the ratio of the calorimeter and input energy rates |
