Research And Development Of Self-operated Three Way Valve For Combined Air-conditioner

In the rapid construction process of our country’s urbanization, industrializationand informatization, a large number of high heat spaces and areas with the loadcharacteristic of inner zone appear, which need an whole year round cooling.However, using conventional refrigeration technology for its cooling will lead to highenergy consumptionand will seriously influence the progress of energy saving andemission reduction of related industries. According to previous research, thecombined air-conditioner, based on the heat pipe/vapor compression refrigerationcombined technology, is a kind of energy-saving and material-saving equipment. Ithas special applicability and effectiveness to cool the annual-cooling-demanded space.In the system, the mode conversion device to switch the combined air-conditionerworking between the natural cycle and vapor compression refrigeration circulation isthe soul of success to the combined air-conditioner, and directly affect reliability andenergy conservation effect. In this work, by means of simulation and experimentalresearch, the design method of self-operated three way valve is explored, and flexible,safe and reliable self-operated three way valve products are developed, which has acertain theoretical meaning and important engineering application value. Main studyof the paper is as follows:(1) According to the working principle of combined air-conditioner and functionrequirement of the mode switching device, the piston self-operated three way valve，the column self-operated three way valve and advanced slide self-operated three wayvalve are put forward, and the applicability of them is analyzed.(2) Mathematical model of thermodynamic and kinetic dynamic characteristicfor piston self-operated three way valve is established, and the model is validatedthrough the established performance test bench of self-operated three way valve. Thevalidation results show the simulation results are in good agreement with theexperimental results. Then the model is applied to analyze influence of compressordischarge rate, spring stiffness, fit clearance and piston length on the dynamiccharacteristics. Analysis results are used to optimize design parameters and develop the better three way valve. The study work provides methodology for research anddevelopment of other type of three way valve.(3) Two different kinds performance test device of self-operated three wayvalves are developed. Performance experiment device is applied to test the productvalves. Experimental results show that the valve acts sensitively, switchs reliablely,seals well, has a long service life, and can serve in combined air-conditioner safelyand reliablely above5years. Field quality test device is developed for airconditioning factory to inspect on-site performance of product valve.(4) Developd valve is employed in combined air-conditioners, and unitshave been tested in the enthalpy difference laboratory and base station, themeasured results show that the valve can reliably and efficiently achieve modeconversion of the unit, ensure energy saving effect, and obtain energy savingrate30%~40%compared to common base station air-conditioning sets.