Heat pumps and their applications

Аннотация

Recently, there has been a significant interest in heat pumps (HP) both in our country and abroad. The areas of their application have also expanded. This is primarily due to rising energy prices and environmental issues. Therefore, research on increasing the energy efficiency of heat pumps remains a relevant topic. This paper examines the design and working principle of heat pumps. Additionally, it analyzes the different types of heat pumps and ways to improve their energy efficiency. Keywords: Heat pumps (HP), World Energy Committee (WEC), higher-temperature body. Introduction: According to forecasts by the World recovery. Undoubtedly, such projects are much more Energy Committee (WEC), by 2020, 75% of heating efficient than conventional heating methods. However, supply (both municipal and industrial) in developed they are also actively supported and subsidized by the countries will be provided by heat pumps. Heat pumps government. have been successfully used in households and Uzbekistan’s Potential for Heat Pumps industries in Europe and the United States for more Uzbekistan has great potential for utilizing solar energy. than 25 years [1,2]. One of the key measures for its utilization is converting A heat pump is essentially a refrigeration machine that it into low-potential thermal energy, particularly for transfers heat from a lower-temperature body to a hot water supply and heating needs. However, due to higher-temperature body, thereby increasing its technical and economic limitations, autonomous solar temperature. Heat pumps serve as alternative energy heating systems have not yet gained widespread use in sources, allowing the production of affordable heat the country. The main reason is the inability to receive without harming the environment. Their unique stable heat from solar systems throughout the year. feature is the ability to convert low-potential heat from The high dependence on fossil fuels in our energy the environment—such as the ground, water, or air— supply is becoming a problem due to limited reserves into high-potential thermal energy for consumers. In of oil and gas [8]. many countries, this eco-friendly technology has only Many scientific and popular science studies have been recently become widely adopted. dedicated to heat pump design and operation Just like in refrigeration machines (RMs), heat pumps principles [3,4,5,12]. transfer heat from a low-temperature medium to a A heat pump is essentially a refrigeration machine that higher-temperature medium. transfers heat from a lower-temperature medium to a It is also worth noting that heat pump technology has a higher-temperature medium, increasing the long history, dating back to the 1950s. This technology temperature of the latter. Heat pumps serve as has been well-developed by foreign specialists and is alternative energy sources, allowing the production of widely applied in construction projects across Europe, affordable heat without harming the environment. the U.S., and Japan. The majority of these projects The working principle of a heat pump is based on the involve comprehensive energy supply systems that fact that any object with a temperature above absolute include ventilation, heating, hot water supply, and heat zero contains thermal energy. The amount of energy American Journal of Applied Science and Technology 61 https://theusajournals.com/index.php/ajast American Journal of Applied Science and Technology (ISSN: 2771-2745) stored is directly proportional to the mass and specific accompanied by the release of heat, which is used for heat capacity of the substance. the home heating system and domestic hot water For example, seas, oceans, the atmosphere, and supply (DHW). underground water have enormous thermal energy Reduction of Refrigerant Pressure (Expansion) reserves due to their large mass. Therefore, a portion Now, the liquid refrigerant needs to be prepared to of this vast energy resource can be extracted using heat repeat the working cycle. To achieve this, the pumps for heating buildings and other thermal refrigerant passes through a narrow opening in the processes without negatively impacting the global thermostatic expansion valve (TXV). environmental balance. After being pushed through the narrow expansion Compression of Refrigerant by the Compressor valve opening, the refrigerant expands, causing its At the next stage, the refrigerant in its gaseous state temperature and pressure to drop. This process is enters the compressor. Here, the compressor similar to spraying an aerosol from a can. After compresses the refrigerant (Freon), which causes a spraying, the can becomes cold for a short time. This sharp increase in pressure and, consequently, an occurs because of the sudden pressure drop as the increase in temperature. A similar process occurs in a aerosol is released, leading to a corresponding drop in household refrigerator compressor. The only temperature. significant difference between a refrigerator A