Pump system energy assessment

2019 ◽  
Keyword(s):  
Pump System ◽  
Energy Assessment ◽  
System Energy

Effects of the operation parameters of a closed-type heating tower on the performance of heating tower heat pump system

2020 ◽  
Vol 38 (5) ◽  
pp. 1983-1997
Author(s):  
Feng Rong ◽  
Li Xiuzhen ◽  
Zhao Xingcheng ◽  
Fang Junfei
Keyword(s):  
Heat Pump ◽  
Freeze Solution ◽  
Coefficient Of Performance ◽  
Heat Absorption ◽  
Efficiency Ratio ◽  
Pump System ◽  
Heat Pump System ◽  
Closed Type ◽  
System Energy ◽  
Operation Parameters

The ventilator of the heating tower and the circulating pump of the anti-freeze solution are the main electrical equipment of a heating tower heat pump system, besides the compressor. By controlling the working frequencies of the ventilator of the heating tower and circulating pump of the anti-freeze solution, the effects of the operation parameters of a closed-type heating tower on its heat absorption and the performance of heating tower heat pump system were investigated under winter heat conditions. The results indicated that reducing the frequency of the circulating pump for the anti-freeze solution leads to a decrease in the temperature of the outlet evaporator of the anti-freezing solution and an increased temperature difference between the anti-freeze solution flowing into and out of the heating tower; meanwhile, excessively high and low anti-freeze flow rates lead to reduced heat absorption of the closed-type heating tower. The coefficient of performance fluctuates slightly if the frequency of circulating pump is above 20 Hz, but a slight drop in coefficient of performance is observed when the frequency is less than 15 Hz. The system energy efficiency ratio tends to increase as the frequency of circulating pump is reduced, although a substantial reduction occurs at 10 Hz. Furthermore, a reduced ventilator frequency decreases the temperatures of the anti-freeze solution at the inlet and outlet of the heating tower and the temperature difference, hindering the heat absorption of the heating tower. With reductions in the ventilator frequency, the coefficient of performance exhibits an initial increase followed by subsequent decreases, while the system energy efficiency ratio showed continual increases until the ventilator frequency dropped to 10 Hz. When the ventilator frequency or circulating pump frequency drops to 15 Hz and 10 Hz, the evaporation temperature of the heat pump unit decreases, resulting in an excessively exhaust temperature, which is not favorable for the safe operation of the system.

scholarly journals Energy assessment of hybrid heat pump systems as a retrofit measure in residential housing stock

2019 ◽  
Vol 111 ◽  
pp. 01064
Author(s):  
David Keogh ◽  
Mohammad Saffari ◽  
Mattia de Rosa ◽  
Donal P. Finn
Keyword(s):  
Heat Pump ◽  
Fossil Fuel ◽  
Energy Savings ◽  
Housing Stock ◽  
Primary Energy ◽  
Pump System ◽  
Heat Pump System ◽  
Energy Assessment ◽  
Electric Heat ◽  
Hybrid Heat Pump

Hybrid electric-gas heat pump systems are a possible retrofit option in older residential buildings. Older buildings can be challenging to retrofit and in this context hybrid systems can offer an intermediate route to decarbonisation of building heating energy demand. This is especially the case, where deep retrofit measures coupled with monovalent electric heat pump systems may not be feasible from an economic perspective. The aim of the current paper is to examine the suitability of a hybrid electric-gas heat pump system in comparison to electric heat pump systems as a retrofit measure for Irish housing stock and to benchmark both options against existing fossil fuel baseline systems. A detailed building energy model of a residential dwelling was developed and calibrated to within acceptable ASHRAE standards. An energy assessment was carried out which investigates each retrofit scenario. Key findings include: (i) both the all-electric and hybrid heat pump systems deliver primary energy savings compared to the fossil fuel baseline systems, (ii) hybrid systems attain higher primary energy savings compared to all-electric heat pump, where the hybrid system incorporates flexible delivery temperatures compared to a fixed delivery temperature tor the all-electric heat pump system.

scholarly journals Applying Criteria Equations in Studying the Energy Efficiency of Pump Systems

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5256
Author(s):  
Gencho Popov ◽  
Stanislaw Legutko ◽  
Kliment Klimentov ◽  
Boris Kostov
Keyword(s):  
Energy Efficiency ◽  
Flow Rate ◽  
Specific Energy Consumption ◽  
Pump System ◽  
Variable Frequency Drive ◽  
Pipe System ◽  
Energy Assessment ◽  
Approach Method ◽  
Static Head ◽  
First Time

This paper presents a method for evaluating the energy efficiency of pump systems used to transport fluids .It is mainly scientifically applied and engineering-applied in nature and aims to propose a new approach (method) to researchers in their study of the energy efficiency of such systems. By applying the well-known scientific method of Dimensional Analysis (Buckingham π-theorem), dimensionless complexes (π-criterions and their relevant equations, which are original (innovative) and are offered for the first time in the scientific literature), used in accomplishing an energy assessment and analysis of such systems, are obtained. The criterion ∏1 = ev/ρgD represents specific energy consumption in kWh/m3 for a given pipe system with an exemplary diameter D. The criterion ∏2 = Q/[n(Hp − Hst)D2] represents a generalized parameter which is characterized by the selected method of flow rate (Q) regulation for a pump system with given static head Hst—by changing the speed of rotation (VFD, Variable Frequency Drive), by throttling, leading to an increase of the system hydraulic losses hv = (HpHst) or by diverting a part of the flow, known as “by-pass”, where the pump operates with the required system head Hp, but ensures higher flow rates, i.e., Qp > Qs. The flow rate criterion ∏3 = Q/(νD) characterizes the flow rate for a pipe system with an exemplary diameter D, used to transport a liquid with known viscosity ν. An example for applying these dimensionless complexes in accomplishing a quantitative evaluation of the energy efficiency of a given pump system is presented. A method for determining the main parameters forming these criterions, used to describe the different methods of flow rate regulation, has been developed. To demonstrate the application of this method, newly proposed by the authors, including obtaining the relevant criteria equations of the type ∏1 = f(∏2, ∏3), a certain pump system was used. This original approach for studying pump systems used to transport fluids can be used both to accomplish an energy analysis of such systems as well as to solve for optimization or other engineering problems.

scholarly journals System Energy Assessment (SEA), Defining a Standard Measure of EROI for Energy Businesses as Whole Systems

2011 ◽  
Vol 3 (10) ◽  
pp. 1908-1943 ◽  
Author(s):  
Philip F. Henshaw ◽  
Carey King ◽  
Jay Zarnikau
Keyword(s):  
Standard Measure ◽  
Energy Assessment ◽  
System Energy ◽  
Whole Systems

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

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