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This article deals with the degrees of freedom and possible optimums, specifically with the energy optimums of the heat pump heating system. The authors developed an multi objective optimization procedure that allows for the determination of the optimal motor power for the circulation and well pumps in order to achieve the maximum C O P . Upon selecting the type and size of the water-to-water heat pump, based on the heating demand of the buildings, the proper power of the circulation and well pumps must be determined. There are several procedures used for determining the pump's power. However, none of those methods ensures the optimum power, i.e., the maximum coefficient of performance, C O P of the heating system. In this study, a multi objective analytical-numerical dimensioning procedure was developed for the determination of the optimal mass flow rate of warm and well water. Based on the flow rate values, the optimum power of the circulation and well pumps can be calculated. Due to the wide scope of the topic, the application of the optimization procedure is presented in a case study, but only for determining the optimum power of the circulation pump. The validity of the procedure was confirmed by measurements. The results obtained with the optimization showed that through the energy optimization of the circulation pump power, the C O P of the system increased by 5.34%. [ABSTRACT FROM AUTHOR]

The paper presents the energy optimization of the cold water loop of the heat pump heating system using analytical-numerical procedure. The aim of the study is obtain the maximum COP of the heating system by optimum of the wall water mass-flow rate and well pump power. The objective function is the heating system’s COP. All components of the heating system: evaporator, condenser, compressor, circulation pump, and well pump are described by steady-state, lumped mathematical model. The model’s equations are coupled, non-linear, multivariable and algebraic, the solution is feasible using an iterative numerical method. The MATLAB’s program with Gauss elimination and Newton-linearization method is applied for solving the model. The obtained numerical data are presented in 3-D graphics. The optimum value of the cold-well water mass-flow rate is obtained from the graphics or by using a selection algorithm. The results of the study are the adequate mathematical model for energy optimization of the heating system, the numerical algorithm for solving the model and the ultimate goal to obtain the optimum of the power of well pump and compressor. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mathematical model of the heat pump plate condenser is nonlinear, steady-state, and lumped. [•] Numerical procedure Newton–Taylor linearization and Gauss elimination method. [•] Variables: water inlet temperature, pressure drop, c. pump power, and condenser surface. [•] Condenser performance as a function of c. pump power, pressure drop, and condenser surface. [•] Graphics of the condenser performance in two- and three-dimensional. [Copyright &y& Elsevier]

The aim of this article is to present the reason and the process of creating new modified mathematical model of heat pump plate condenser. The fundamental mathematical model is modified according to analytical optimization procedure. The adaptation is carried out by applying the procedure of elimination. The modified mathematical model include 2 governing equations instead of 6. The two governing equations contain 2 unknown dependent variables and 6 known parameters. The modified mathematical model is validated using the comparative method. The compared data are obtained by numerical simulation using fundamental and modified mathematical models. Applying both models the obtained data fully coincided. By using the new modified mathematical model and implementing the optimization process may lead to the determination of the maximum energy efficiency of hot water subsystem. The subsystem comprises a condenser, a circulation pump, a connecting pipeline and the heating units. The objective function in the optimization process is the coefficient of performance, COP, as a function of the mass flow rate of the hot water or of the circulation pump power. The paper offers the implementation of modeling the circulation pump power to achieve the maximum value of the COP. [ABSTRACT FROM AUTHOR]