The evaporation temperature is regarded as one of the major parameters influencing the organic Rankine cycle (ORC) efficiency. Majority of contributions in literature for ORC cycle analyses treat the heat source as if it had an infinite heat capacity. Such analyses are not valuable as the resulting temperature drops of the heat source needs to be small. That leads to the fact that the heat source is not well explored and in the case of waste heat utilization it can prove the poor economics of the ORC. In the present study cooperation of the ORC cycle with the heat source available as a single phase or phase changing fluids is considered. The analytical heat balance models have been developed, which enable in a simple way calculation of heating fluid temperature variation as well as the ratio of flow rates of heating and working fluids in ORC cycle. The developed analytical expressions enable also calculation of the outlet temperature of the heating fluid.

This article presents the current and future situation of heat consumption in the Republic of Kazakhstan. The predicted growth of thermal loads until 2030 is shown in the example of Karaganda city. Therefore, the task of creating and implementing automated heat points into the system of heat-supply complexes of cities of the Republic of Kazakhstan is relevant. The article considers the concept of measurement and processing of information in district heating supply systems based on variable cycles of the interrogation of parameters of heat supply at the heat points. As a result of the conducted research, a microcontroller SMART-system for the implementation of rational modes of heat supply used in the process of obtaining and processing information on heat-consumption parameters and making control decisions regarding variable cycles of heat-supply-parameter interrogation at heat points was developed and implemented. The results of the study have been successfully tested on the facilities equipped with automated heat points.