The paper considers the types and classification of industrial PID controllers according to various types and groups. A group of linear controllers has been identified, which includes PID controllers, which are most widely used in various technical devices. Some well-known software systems that provide calculations for PID controllers are given. The transition from the mathematical notation of the trapezoidal expansion of the transfer function of the PID controller, used in the PID Tune option of the Matlab environment, to the equivalent transfer function, represented by the symbolic coefficients of the numerator and denominator polynomials, is shown. A theorem is proved that shows a one-to-one correspondence between the parameters P, I, D of the controller and the coefficients of the resulting transfer function. Flowcharts of algorithms for calculating transfer function coefficients (TF) from known values of controller parameters and calculating transfer function coefficients from known values of controller parameters are given. An illustrative example is considered.

Keywords: PID controller, transfer function, block diagram of the algorithm, Matlab environment

The article discusses the constructive and conceptual solutions associated with the implementation of the main devices of the central air conditioner, working in conjunction with the chiller. The peculiarity of the implementation of these devices is dictated by the use of solar energy. The receivers of solar energy are solar collectors, in which the heating medium is heated, which is used as a heat source in the chiller generator.

Keywords: solar energy, central air conditioner, chiller, absorption refrigeration machines, vacuum solar collector

A model of a household refrigeration machine (BHM) is considered. The refrigerating capacity, thermal load are determined, the compressor and operational parameters are calculated, the cycle of the chiller in p-i coordinates is built.

Keywords: household refrigerator, temperature, refrigerator, heat load, cooling capacity, compressor, heat influx

The work is devoted to the consideration of problems and the state of use of alternative energy sources. The description of various types of refrigerating machines using solar energy for air conditioning systems of administrative and residential buildings is given.

Keywords: solar energy, secondary heat sources, absorption refrigeration machines, lithium-methanol bromide mixture.