scholarly journals EFFICIENCY OF PUMP OPERATION IN HYDRONIC HEATING AND COOLING SYSTEMS

2006 ◽  
Vol 12 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Per Fahlén ◽  
Hendrik Voll ◽  
Jüri Naumov
Keyword(s):  
Flow Control ◽  
Heat Pump ◽  
Pump Efficiency ◽  
Drive Power ◽  
Direct Flow ◽  
Cooling Systems ◽  
Pump Operation ◽  
Quality Of Control ◽  
Heating And Cooling ◽  
Air Conditioning Systems

Developments in pump technology provide new possibilities of improving both the efficiency and the quality of control of hydronic heating and cooling systems. Improved pump efficiency and direct flow control can substantially reduce the drive power to circulation pumps. Measurements show that a simple VSD (variable speed drive) does not unduly degrade the efficiency of commonly used pumps. An example from a residential heat pump installation indicates possible savings of around 30 % of the total drive energy to the heat pump. Another example illustrates how direct flow control can simplify systems and reduce electric drive power in supply‐air conditioning systems.

Combined Solar Heating and Cooling Systems: Simulation and Design Optimization

2008 ◽  
Author(s):  
Giovanni Nurzia ◽  
Giuseppe Franchini ◽  
Antonio Perdichizzi
Keyword(s):  
Design Optimization ◽  
Heat Pump ◽  
Solar Heating ◽  
Solar Irradiation ◽  
Space Heating ◽  
Thermal Source ◽  
Absorption Chiller ◽  
Cooling Systems ◽  
Detailed Model ◽  
Heating And Cooling

The deployment of solar driven air conditioning is a feasible target in all countries where high solar irradiation matches high cooling loads in buildings: the goal is to gradually replace compression chillers and reduce peak electricity demand during summer. Moreover, as solar thermal collectors are installed, solar cooling systems can be profitably employed during winter. In the present work a code has been implemented for the simulation and the design optimization of combined solar heating and cooling systems. The following system layout has been considered: in warm months the cooling demand is satisfied by means of an absorption chiller — driven by a solar collector field — and a reversible heat pump operating in series. A hot storage matches the variability of solar radiation, while a cold storage smoothes the non-stationarity of cooling demand. During winter, the reversible compression heat pump operates for space heating. Solar collectors are used as thermal source at the evaporator of the heat pump, increasing its coefficient of performance. The code, based on TRNSYS platform, is able to simulate the system throughout a year. Besides TRNSYS standard components a detailed model of the absorption chiller has been included, in order to accurately simulate its off-design operation. Using an optimization tool the size of each component is identified for a given space heating and cooling demand. The minimization of life cycle costs of the system has been chosen as the objective of the optimization. Results of a case study are presented and discussed for a solar heating and cooling plant in an office building. The optimization procedure has been carried out with simulations for a typical Northern Italy town (Alpine climate) and a typical Southern Italy town (Mediterranean climate).

The study of solar absorption air-conditioning systems

2005 ◽  
Vol 16 (4) ◽  
pp. 59-66 ◽  
Author(s):  
V Mittal ◽  
KS Kasana ◽  
NS Thakur
Keyword(s):  
Air Conditioning ◽  
Lithium Bromide ◽  
Cooling Systems ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Heating And Cooling ◽  
Absorption Cooling ◽  
Solar Powered ◽  
Solar Absorption Cooling ◽  
Air Conditioning Systems

An air-conditioning system utilizing solar energy would generally be more efficient, cost wise, if it was used to provide both heating and cooling requirements in the building it serves. Various solar powered heating systems have been tested extensively, but solar powered air conditioning systems have received very little attention. Solar powered absorption cooling systems can serve both heating and cooling requirements in the building it serves. Many researchers have studied the solar absorption air conditioning system in order to make it economically and technically viable. But still, much more research in this area is needed. This paper will help many researchers working in this area and provide them with fundamental knowledge on absorption systems, and a detailed review on the past efforts in the field of solar absorption cooling systems with the absorption pair of lithium-bromide and water. This knowledge will help them to start the parametric study in order to investigate the influence of key parameters on the overall system performance.

Condensation Induced Shock in Thermal/Fluid Systems

2012 ◽  
Author(s):  
Amir Jokar ◽  
Erik W. Christiansen
Keyword(s):  
Shock Waves ◽  
Phase Change ◽  
Air Conditioning ◽  
Industrial Applications ◽  
Governing Equations ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Fluid Systems ◽  
Air Conditioning Systems ◽  
Effective Life

Phase-change through condensation and evaporation processes takes place in many daily-use heating and cooling systems. However, if these processes experience uncontrolled pressure and temperature conditions, shock waves may be generated. Depending on the strength and conditions of the generated waves, they can decrease the effective life of equipment or even cause devastating destruction. Cavitation and water hammer phenomena are examples of flow issues that are well understood and reported in thermal/fluid systems, although not many studies have been published in open literature on condensation-induced shock (CIS) with the applications in refrigeration and air conditioning systems. This study reviews the limited literature on this topic, analyze the complex CIS phenomenon, derives and solves the governing equations, presents the results of typical conditions that may happen in different residential and industrial applications, and provides ways to avoid devastating incidents that may occur as a result of this phenomena.

scholarly journals Efficiency of Passive Utilization of Ground “Cold” in Adaptive Geothermal Heat Pump Heating and Cooling Systems (AGHCS)

2016 ◽  
Vol 77 ◽  
pp. 06008
Author(s):  
G.P. Vasilyev ◽  
V.F. Gornov ◽  
M.V. Kolesova ◽  
A.N. Dmitriev ◽  
V.G. Silaeva
Keyword(s):  
Heat Pump ◽  
Geothermal Heat ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Geothermal Heat Pump

Heat Pump Heating and Cooling Systems

2016 ◽  
pp. 129-165 ◽  
Author(s):  
Ioan Sarbu ◽  
Calin Sebarchievici
Keyword(s):  
Heat Pump ◽  
Cooling Systems ◽  
Heating And Cooling
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