In issue 6/2023

Keywords: CAPEX, geothermal heat plant, district heating system, heat plant of the future, clean heat, efficient district heating system, LCOH, OPEX, flammability and explosiveness factor, heat pump, global warming potential, P2G, energy transformation, V2G

Abstract
The topic of the article is the role heat pumps already play and will play in the near future, in the transformation of the Energy heating and district heating. It is clear that Without greater use of heat pumps, it will be impossible Decarbonization of construction, electrification of heating/cooling and achieving energy efficient status District heating system, especially in the case of systems of low and medium power. However, the use of heat pumps creates many denominations and threats not only technical and economic, but also safety and reliability of operation related, among other things, to pump operating factors Heat and the extraction of low-temperature heat from the lower sources. In addition, the parameters of the useful heat produced in heat pumps force significant changes in transmission networks and consumer installations (central heating and hot water).

Keywords: shell and tube heat exchanger, flow turbulization, tube overpressure, flow simulation

Abstract
The article presents a shell-and-tube heat exchanger low power with flow and thermal analysis performed for two variants including straight pipes and embossed pipes which is a modification that intensifies the exchange process Heat. Both exchangers are designed as four-way exchangers In order to minimize their dimensions. The purpose of the designed of the heat exchanger is to heat domestic water by means of heat extracted from hot water transferred siecią ciepłowniczą. The article presents the author’s layout partitions characterized by a constant number of pipes and a constant surface area factor flow in each of the four flow paths water. A computational process supported by numerical simulation in ANSYS software, which modeled the Fluid flow through the designed heat exchangers. The study provides results comparing and evaluating the impact of the modifications to the heat transfer process. As a result of the use of in the shell-and-tube heat exchanger of pressed tubes increased Heat exchange intensity by 34.6% relative to the exchanger With straight pipes with a diameter of 16 mm. Significant improvement The intensity of heat exchange has significantly affected the process Miniaturization of the exchanger.

Keywords: trigeneration, heat pump, gas chiller

Abstract
The article addresses issues related to raising the efficiency of trigeneration gas units “producing” heat, cooling and electricity in a combined manner. A new concept was also presented with regard to construction, As well as an innovative approach to the way the aggregate is controlled. In the construction of the device, special emphasis was placed on Heat recovery, both coming directly from the radiator of the internal combustion engine as well as from the exhaust gases, by cooling them down And the condensation of the water vapor contained in them. Warmth was also obtained from the engine body, the compressor that drives the refrigeration system and power generator housings. The manner of control includes both primary objectives and also power supply and correct operation of equipment and installations entering in the composition of the trigenerator and their optimal use to increase efficiency, durability and functionality The device as a whole.

Keywords: renewable heat source, heating, cells photovoltaic, heat pump

Abstract
The article presents an economic analysis of the use of A photovoltaic installation with a designed capacity of 7.2 kWp. Analysis, in this and the following articles, will be carried out In light of the changing law in Poland on renewable energy sources. The first article presents an analysis of Settlement of the energy produced on the basis of the so-called. old system, based on discounts of 1:0.8. At work An attempt was made to analyze the profitability of the above installation in the selected variant and the payback time was calculated. In the following Articles will present an analysis of the cost-effectiveness of application of photovoltaic installation using A new billing system for the sale of surplus energy Into the network. In addition, the designed PV installation will be expanded with battery energy storage facilities, the company said. In the amended RES Act. Photovoltaic installations have been designed to meet the needs of the A single-family house, the heat source of which will be a pump Heat.

Keywords: facade ventilation, alternate supply/ exhaust, airflows

Synopsis:
Introduction. Trends moving toward energy efficiency in buildings are often associated with inadequate air exchange in buildings and deterioration of indoor air quality. One Of the solutions to improve the situation are installations with alternating supply and exhaust. The research presented in the article A decentralized facade ventilation unit was subjected to. Its task is to improve the indoor microclimate. Objective. The purpose of the study is to analyze the size of the airflow depending on the heat recovery exchanger used. Methods. A decentralized facade device was analyzed realizing alternate supply and exhaust by opening the and closing of the dampers, which direct the airflow to the wire networks. The device is equipped with a fan and Heat recovery exchanger section. Three configurations were studied equipment (without heat recovery exchanger, exchanger filled with gravel, exchanger filled with gypsum). Three cycle setting options were analyzed: 2, 6 and 10 minutes. The supply/exhaust airflow was measured at the using a balometer. Conclusions and reference to practical applications. Test results show that the air flow supplied/exhausted by the device of decentralized facade ventilation is sufficient For ventilating living quarters. Least airflows were observed in the variant with the exchanger For heat recovery filled with gravel. Stream of exhaust air in each case analyzed was smaller than the supply air flow rate. Device analyzed effectively exchanges air, but the requirements The laws in force in Poland do not allow the use of this type of solution as a way to ventilate premises. Hence, changes in regulations are necessary As well as subsequent studies regarding the effectiveness of the use of Heat recovery and thermal comfort capabilities.