| Abstract [eng] |
First of all, the volume of this Master Thesis is 67 pages. It is composed of 5 tables and 34 images and 2 attachments. This thesis was written based on 22 sources of reference. The main objective of this thesis was to develop and investigate the control system method for combined Heat pump and evacuated-tube solar collectors system. In order to achieve the above mentioned objective the following tasks were created: 1. To analyse the typical operating principles of solar collectors and heat pumps, as well as their main characteristics and mathematical models. 2. To study the differences among different heat pump operating options: when power is controlled and uncontrolled. 3. To create and test program algorithm which would select best parameters and the most suitable optimal control mode for the heat pump compressor. The thesis investigated the existing types of solar collectors and combined heat pumps, their operating principles and constructions. Also, statistical data regarding the potential of solar thermal energy use in Lithuania was provided. This Master thesis includes descriptions of methods which are applicable during the process of choosing optimization criteria, as well as, for solving various tasks and problems related to optimal control. Also provided are derived equations and principles of writing energy balance equations for evacuated-tube solar collector, boiler and heat pump parts, such as evaporator and condenser. Additionally provided is the main algorithm scheme, which was used to determine the optimal heat pump compressor capacity and its operating modes in different environmental conditions. Finally, the effectiveness and accuracy of the created algorithm was tested by entering settings that are used for existing systems. Summarizing, it can be stated that the results of this thesis research are applicable for solving optimal control tasks when elements for combined system need to be selected and their working principles need to be mutually adjusted. |
