Field Investigation and Comparison Analysis of Low-Grade Heat Pump Technologies in Building Space Heating Projects

Systems of heat consumption of the building with heat pump that uses low-grade heat source are investigated. Effectiveness of heat consumption systems with heat pump is concluded effective for severe climatic conditions prevailing in Russia. Characteristics of heat consumption system with heat pump and the traditional heating system are compared. In this case the heat pump is used the warmth of the environment, that is why considered operating conditions for the autumn and spring. Low inertia of heat systems with heat pump compared to traditional ones during autumn and spring proved.

Download Full-text

ENVIRONMENTALLY SAFE USAGE OF HYDROPOWER POTENTIAL BY HYDROTHERMAL POWER SUPPLY SYSTEMS

Visnyk of Taras Shevchenko National University of Kyiv Geology ◽

10.17721/1728-2713.87.10 ◽

2019 ◽

pp. 67-75

Author(s):

S. Goshovskyi ◽

O. Zurian

Keyword(s):

Heat Pump ◽

Energy Systems ◽

Hydrothermal Systems ◽

Heat Energy ◽

Operating Conditions ◽

Small Rivers ◽

Low Grade ◽

Hydropower Potential ◽

Environmentally Safe ◽

Low Grade Heat

The article contains the results of scientific research and design work related to environmentally safe usage of hydropower potential of the small rivers of the Dnieper basin. The innovative design solutions for extraction of low-grade heat energy of water and systems for its transformation into energy convenient for consumption were offered. It was established that use of renewable low-grade energy of soil is widely used in environmentally safe and economically sound power systems. At the same time hydropower potential is not widely used in hydrothermal heat pump systems. It was proved that existing hydrothermal systems are not always adjusted to actual operating conditions and object location. The evidence was provided that the scientific approach to development of appropriate configuration of hydrothermal collector, to methodology of their optimal mounting and to efficiency determination depending on operating conditions is quite topical issue. The scientific novelty of the new process approach is use of special design of water collector that has modular configuration and consists of several functionally related water sondes. The efficiency of hydrothermal system was scientifically proved. The paper describes the results of experimental research of efficiency of hydrothermal heat pump system where the low-grade heat energy of water is used as a renewable primary heating energy source for functioning of the heat pump. The authors have developed experimental hydrothermal and geothermal heat pump systems to conduct the research. Both collector and ground section of the system have mounted sensors of temperature, pressure and coolant flow velocity. The software for archiving and visualization of obtained data was developed. The research procedure was developed. As part of study, observation data were received and performance efficiency of geothermal and hydrothermal systems was calculated. The comparative analysis of energy systems depending on used renewable energy source was carried out. The conclusion was made that use of hydrothermal heat pump systems is environmentally safe. The data obtained as part of study have great scientific and applied significance for engineering of heat pump energy systems using hydropower potential of the small rivers.

Download Full-text

RESEARCH OF AUTOMATIC HEAT CONTROL SYSTEMS

URBAN CONSTRUCTION AND ARCHITECTURE ◽

10.17673/vestnik.2016.02.23 ◽

2016 ◽

Vol 6 (2) ◽

pp. 129-134

Author(s):

Anna A. TSYNAEVA ◽

Ekaterina A. TSYNAEVA

Keyword(s):

Heat Source ◽

Control Systems ◽

Heat Pump ◽

Numerical Study ◽

Theoretical Method ◽

Climatic Conditions ◽

Low Grade ◽

Heat Control ◽

Heat System ◽

Low Grade Heat

This paper deals with automatic control systems of heat consumption of buildings. As a method of study we used computational and theoretical method using the theory of differential equations, control theory, methods of analysis and synthesis, including the numerical experiment. In this paper, a comparison of the characteristics of an automated heat control system in buildings, using the heat pump from the low-grade heat source, as well as conventional systems, receiving heat from the CHP for heat networks. Numerical study carried out for conditions of autumn-spring period, as during the research of heat system, the environment is selected as the low-grade heat source. Moreover, It is analysed climatic conditions start of the heating period in 2014 and 2015. for the city of Samara. Based on the numerical investigation revealed that for the autumnspring period automated heat system with a heat pump has a lower inertia than a conventional system with.

Download Full-text

Combined Desalination and Refrigeration Systems Driven by Low-Grade Heat

Volume 8: Energy Systems: Analysis, Thermodynamics and Sustainability; Sustainable Products and Processes ◽

10.1115/imece2008-67029 ◽

2008 ◽

Cited By ~ 1

Author(s):

Yongqing Wang ◽

Noam Lior

Keyword(s):

Heat Pump ◽

Gas Turbines ◽

Air Conditioning ◽

Saturation Pressure ◽

Coefficient Of Performance ◽

Saturated Steam ◽

Low Grade ◽

Absorption Refrigeration ◽

Wide Range ◽

Low Grade Heat

There is often a need for both water desalination and cooling (refrigeration/air-conditioning). The cooling can be used to significantly raise system efficiency by compressor inlet cooling in a dual-purpose power-generation and desalination system using gas turbines, or simply to supply refrigeration or air conditioning beside fresh water. Motivated by the good synergetic potential of energy/exergy utilization through the combination of the LiBr-H2O refrigeration unit, LiBr-H2O heat pump, and low-temperature multi-effect evaporation desalter, two combined refrigeration and water systems, ARHP-MEE (Absorption Refrigeration Heat Pump and Multi-Effect Evaporation desalter) system and ARHP-AHP-MEE (Absorption Refrigeration Heat Pump + Absorption Heat Pump + Multi-Effect Evaporation desalter) system, driven by low-grade heat were configured, modeled and analyzed in detail in the paper. Typically, driving steam with saturation pressure of 0.15–0.35 MPa and correspondingly saturation temperature of 111.4–138.9°C is applicable to run the systems. The main results are: (1) the combined systems have good synergy, with an energy saving rate of 42% in a case study of ARHP-MEE; (2) the refrigeration-heat cogenerated ARHP subsystem is the main reason for the synergy, where the coefficient of performance is around 1.6 and exergy efficiency above 60% when driven by 0.25 MPa saturated steam; (3) at the cost of a more complex configuration, the ARHP-AHP-MEE system has the ability of varying its outputs in very wide range, offering good flexibility on design and operation; (4) the ARHP-MEE system is predicted to have good economics, and its outputs can be varied in a wide range but not independently because their ratio remains almost constant. A parametric analysis was also performed for the ARHP-MEE, further improving the understanding of the system performance.

Download Full-text