Design for Micro-Combined Cooling, Heating and Power Systems

This introductory chapter will blend both legal and technical aspects of microgeneration systems in order to acquaint the readers with the concept and roles of microgeneration systems, the perception of the European Union and the ways of promotion and development through policies and legal instruments. These notions are fundamental for readers and practitioners in the field of microgeneration systems since a variety of factors work in close connection and have a profound influence on the development of microgeneration systems. This chapter will make short explanatory remarks about the evolution (1) of the European Union and the energy sector in Europe in the transition to decentralised energy production and extensive use of microgeneration systems. Afterwards, the challenges (2) confronting the European energy sector are presented in order to understand the way problems are tackled by the European Union through policies (3) and legal instruments (4) to comprehend the use, promotion and trend for development of microgeneration systems (5).

This chapter presents the technologies for achieving Combined Heat and Power (CHP) and micro-Combined Cooling Heat and Power (mCCHP) microgeneration systems. Section 1 presents based on the relevant data from literature the main primary thermal motors used in CHP micro systems. A comparative analysis of cogeneration technologies based on performance indicators is presented in Sect. 2. Section 3 describes the mCCHP systems from the points of view of architectural achievement and operation modes in order to satisfy the residential consumers’ energy needs.

The mCCHP-SE-RES system is defined as a particular combined cold, heat, and power system, which is distinguished in that it is a microgeneration system (mCCHP) dedicated to residential building, the CHP unit is a Stirling engine (SE), and the primary energy is obtained from renewable energy sources (RES). In this chapter, the last feature is presented in detail, aiming to recall the basic data and information needed to design such a system. First, it shows the physical fundamentals of the solar energy conversion into electricity or thermal energy, and then the construction and operation of the photovoltaic and thermal solar panels, as well as of the electrical and thermal energy storages assigned to these panels. Also it shows the technical processes of obtaining and burning the biomass, as well as the construction and operation of the Stirling engine and the boiler that can be fueled by biomass.

In order to be shown in detail, the design process algorithm was divided into two stages, namely structural design and functional design. In this chapter is presented the first stage and in Chap. Functional Design of the mCCHP-RES System the second. Then, in Chap. Experimental Case Study it is shown a concrete example. Here, the structural design is divided into seven steps and of each step has been devoted a paragraph. Regarding the contents of steps, they are as follows The first three steps (described in Sects. 1, 2 and 3) are preparatory and consist of establishment of both the conceptual framework (i.e., delimitation of the space where will be searched solutions for the problems arising during the design process) and the manufacturer business plan (on which is based the choice of design approach that can be open-ended or closed-ended), followed by the initial data collection (namely the data on which is based the design calculations, such as the residence building features, the customer needs and requirements, the functional needs of residence, and the residence energetic environment). The fourth step (described in Sect. 4) consists in building the general structural model of the mCCHP system, based on the data and information gathered in the previous steps, and then in identifying a set of potential structural models by customizing the general model. The last three steps (described in Sects. 5, 6 and 7) consist in both the consumption estimation (for each month of the year and each of the consumers incorporated in the system), and the load estimation (for each month of the year and each energy supplier incorporated in the system), followed by the structural model selection, based on the evaluation and improving the performance of each potential structural model identified in the fourth step. The output of this first stage is the set of acceptable structural models, these representing the input in the second stage, called functional design and presented in Chap. Functional Design of the mCCHP-RES System.

In order to be shown in detail, the design process algorithm (see Fig. 2 in Chapter “Structural Design of the mCCHP-RES System”) was divided into two stages, namely structural design and functional design. In Chapter “Structural Design of the mCCHP-RES System” was presented the first stage while in this chapter is presented the second. Then, in Chapter “Experimental Case Study” it is shown a concrete example. Here, the functional design was divided into five steps and to each step has been devoted a paragraph. Regarding the contents of steps, this is as following: In the first step (described in Sect. 2.1) the acceptable structural models resulted from the structural design stage, are completed with all the complementary components (such as recirculation pumps, expansion tanks, heat exchangers etc.), this way becoming the functional models of the system. After that all the components, main or complementary, are dimensioned taking into account both the energetic consumptions of the residence and the internal energetic consumptions of the system. The next two steps (described in Sects. 3 and 4) consist in establishing the operation and control strategy of the system, based on which then the system dynamics is analyzed numerically. Simulation and analysis of the system operation highlights the system performance in critical moments (such as the coldest/hottest day of the year, for example), in case of each functional model. The step described in Sect. 5 consists in designing the monitoring and control subsystem, which includes choosing the field equipments, design of the connection devices of these equipments to the data acquisition system, design of the monitoring software of the whole system, as well as designing the numerical controllers of the thermal and electric control loops. The last step (described in Sect. 8) consists in designing the system interfaces. Finally, the system designer has at his disposal several functional models, each with advantages and disadvantages, and, on this basis, can make the best decision.

In order to be shown in detail, the design process algorithm (see Fig. 2 in Chap. “Structural Design of the mCCHP-RES System”) was divided into two stages, namely structural design and functional design. In Chap. “Structural Design of the mCCHP-RES System” was presented the first stage while in Chap. “Functional Design of the mCCHP-RES System” was presented the second. Here it is shown a concrete example, which consists in the design of mCCHP system for a familiar type housing. The design was done in accordance with the algorithm, which is shown in Fig. 2 in Chap. “Structural Design of the mCCHP-RES System” and described in Chaps. “Structural Design of the mCCHP-RES System” and “Functional Design of the mCCHP-RES System” in detail. The 12 paragraphs of this chapter contain data resulting from application of the 12 steps of the algorithm. Testing of the real mCCHP system that has been achieved through the practical application of this algorithm confirmed the algorithm validity.