Thermodynamic design data for absorption heat transformers—Part II. Operating on water-calcium chloride
Abstract The Gibbs phase rule and the thermodynamic properties of the working pair limit the choice of operating temperatures. For any combination of the temperatures, the concentrations in the absorber and the generator and hence the flow ratio are fixed. For any particular working pair, the coefficient of performance is related to the flow ratio. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for absorption heat transformers operating on water-lithium bromide. The interaction of operating temperatures has been illustrated graphically.
Simulation and optimization of novel configurations of triple absorption heat transformers integrated to a water desalination system
Abstract A thermodynamic analysis of six different configurations of triple absorption heat transformer systems (TAHTs) utilizing H2O/LiBr as the working pair which is integrated into water desalination systems is conducted in this study. The energy source of the desalination system is provided by the high temperature heat of the absorbers of TAHTs by utilizing the waste heat from a textile factory. A computer program is developed in the EES (Engineering Equation Solver) to study the performance of the system such as; COP, ECOP, distilled water, and absorber utilized heat, and also to optimize them in six different configurations. It is shown that modified configurations of TAHTs can increase the COP and fresh water productivity rather than that of conventional systems. The results indicated that the optimized amount of distilled water produced by the last configuration which is 0.1307 kg/s can supply 1131 residential units.
Fully Integrated Bidirectional CMOS-MEMS Flow Sensor With Low Power Pulse Operation
Leveraging More-than-Moore technology, we demonstrate an integrated CMOS MEMS flow sensor via a very compact system on chip (SoC) that can sense the bidirectional N2 gas flow. Our SoC features a very low-noise instrumentation amplifier that is implemented on a CMOS wafer and serves as a readout integrated circuit for a thermoresistive micro-calorimetric flow sensor which is fabricated on a MEMS wafer. A compact heterogeneous integration is achieved by combining the two wafers via the proprietary InvenSense AlN process. The measured sensitivity of our CMOS MEMS flow sensor is 98 mV/sccm which is three times better than the state-of-the-art counterpart. The flow range measured by our SoC is from −26 to 26 m/s (from −50 to 50 sccm). Moreover, the pulsed heater operation makes this proposed SoC flow sensor a very low power (<9 mW) and, thus, a promising candidate for the Internet-of-Things applications in smart home/green buildings.