The Design And Research On A Regenerative Heat Engine With Double Pistons

With the improvement of social civilization, the energy demand of human beings increased rapidly. While the conventional energy is drying up, it is urgent to develop renewable energy. Solar energy, as a kind of renewable energy, has been widely used because of its convenience and safety. The most general solar application device is solar water heater. Because of its low running temperature(not more than 100 Celsius degrees), the heat energy collected can only be used to heat the water for domestic use and it’s difficult for those energy to be converted to mechanical energy for any other uses. So a new kind of regenerative heat engine with double pistons is introduced in this article, which can convert solar energy to potential energy and absorb heat to work under small temperature difference. Besides, this engine can pump water continually which provides an effective method to combat drought in summer.According to the operating environment and conditions of the heat engine, pump system, heat transfer system, and control system was designed. Based on the minimum rule of condensation side area, the diameter of the cylinder block size in the pump water system was determine. With thermodynamic calculation, the heat exchanger and condenser in the system was designed. Based on the principle of heat engine operation, the design of software and hardware was completed to control all the valves active accurately.Considering the working process of the regenerative engine with double pistons, the working principle was analyzed and the thermodynamic model was established. According to the working condition of the heat engine, four kinds of low boiling point substances were analyzed, including methanol, acetone, R113 and R141 b. Theoretical analysis shows that four substances were almost the same in the thermal efficiency. Considering the environment protecting and safety performance, methanol and acetone are suitable for the heat engine system. Then the thermal efficiency and the cycle influence of the system was analyzed with two substances.An experiment bench of regenerative engine with double pistons was set and methanol was used as working substance. With the data acquisition system, the experiment data was collected and analyzed. The trend of the result is almost the same as the prediction with the theory of heat engine. The maximum flow is 265L/h and the actual thermal efficiency is 0.45% because of the undesirable heat preservation effect. At last, According to the theoretical calculation and experimental results, a summary was made and a developing direction of low-temperature heat engine is proposed.