scholarly journals Non-Invasive Estimation of Domestic Hot Water Usage with Temperature and Vibration Sensors

2019 ◽  
Author(s):  
MJ Booysen
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Consumption ◽  
Flow Measurement ◽  
Hot Water ◽  
Water Usage ◽  
Flow Rates ◽  
Domestic Hot Water ◽  
Non Invasive ◽  
Water Heaters

Electric water heaters are responsible for a large portion of electricity consumption and water usage in the domestic sector. Smart water heaters alleviate the strain on the electricity supply grid and reduce water consumption through behavioural change, but the installation of in-line flow meters is inconvenient and expensive. A non-invasive water flow meter is proposed as an alternative. Non-invasive flow measurement is more common for high flow rates in the industrial sector than for domestic applications. Various non-invasive water measurement methods are investigated in the context of domestic hot water, and a combination of thermal- and vibration-sensing is proposed. The proposed solution uses inexpensive, easily installable, non-invasive sensors and a novel algorithm to provide the same flow measurement accuracy as existing in-line meters. The algorithm detects the beginning and end of water consumption events with an accuracy of 95.6%. Quantitative flow rate estimation was possible for flow rates greater than 5 L min⁻¹ with an accuracy of 89%, while volumetric usage estimation had an accuracy of more than 93%. The algorithm limitations were applied to field data, revealing that water consumption could be detected with an error of less than 12% within the limitations of the proposed algorithm. The paper presents a successful proof of concept for a non-invasive alternative to domestic hot water flow rate measurement.

Non-Invasive Water Flow Sensing for Smart Water Heater Controller

2017 ◽  
Author(s):  
Joe Singer ◽  
Scott Jansen ◽  
Chenli Wang ◽  
Hohyun Lee
Keyword(s):  
Energy Conservation ◽  
Temperature Change ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Hot Water ◽  
Water Usage ◽  
Water Heater ◽  
Non Invasive ◽  
Water Heaters

Water flow rate sensors in residential homes have the capacity to revolutionize energy conservation by providing real time, user specific water usage data to the Internet of Things. Water heaters typically heat water to a constant set-temperature throughout the day. This constant heating contributes to about 18% of total home energy usage, making water heaters an especially effective target for potential energy savings. By harnessing the knowledge of hot water usage and flow rate, machine learning processes can determine an optimized water heating schedule for individual users. However, current methods to determine water flow rate involve either a complicated installation process or use of expensive equipment. The work in this paper proposes an economical, non-invasive package to both detect hot water usage and measure the flow rate, by utilizing three temperature sensors. Processing of the data quantitatively correlates temperature change of the incoming/outgoing water pipes to the water flow rate through the pipes. To accomplish this, the principle of energy conservation was applied using transient temperature measurements taken from the outer surface of both the cold inlet and hot outlet pipes. In the process of formulating energy conservation equations, there exist unknowns which will be determined by different self-testing algorithms. Developing transient and steady state equations for the inlet and outlet pipes allowed for calculations of the flow rate through a water heater to be performed. Specified conservation equations applied to both cold inlet and hot outlet pipes will enhance the accuracy and reliability of the proposed method. For verification, experimental setup was built to verify our model by comparing actual usage and flow rate measurements from a household water heater with the calculated usage and flow rate from the temperature change rate.

scholarly journals Performance of Solar Absorption-Subcooled Compression Hybrid Cooling System for Different Flow Rates of Hot Water

2020 ◽  
Vol 10 (3) ◽  
pp. 810 ◽  
Author(s):  
Jinfang Zhang ◽  
Zeyu Li ◽  
Yue Jing ◽  
Yongrui Xu
Keyword(s):  
Energy Saving ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling System ◽  
Water Flow Rate ◽  
Hot Water ◽  
Solar Absorption ◽  
Flow Rates ◽  
High Rise ◽  
Daily Energy

The solar absorption-subcooled compression hybrid cooling system (SASCHCS) is tech-economically feasible for high-rise buildings. Since such a system operates with no auxiliary heat source, the performance coupling of its absorption subsystem and solar collectors is sensitive to the variation of hot water flow rate. In this regard, the relationship of system performance and hot water flow rate is required to be clarified exactly. Therefore, this paper aims to illustrate the effect mechanism of hot water flow rate and to propose the corresponding decision criterion. The case study is based on a typical high-rise office building in subtropical Guangzhou. The daily working process of this system with different hot water flow rates is simulated and analyzed. Subsequently, the useful heat of collectors and cooling capacity of the absorption subsystem with the hot water flow rate is discussed in detail. The results show that the SASCHCS operates with hot water temperatures ranging from 60 °C to 90 °C. The energy saving increases with the rise of hot water flow rate, but such variation tends to be flat for the excessively high flow rate. As the collector flow rate increases from 1 m3/h to 10 m3/h, the daily energy saving improves by 21% in August. Similarly, the daily energy saving increases by 37.5% as generator hot water flow rate increases from 1 m3/h to 10 m3/h. In addition, the collector flow rate of 3.6 m3/h (13.33 (kg/m2 h)) and the generator flow rate of 5.2 m3/h (19.26 (kg/m2 h)) are optimal for the annual operation, with considering power consumption of water pumps. This paper is helpful for the improvement of SASCHCS operating performance.

scholarly journals Measurement of domestic hot water consumption in hotel rooms with different basin and shower mixing taps

2021 ◽  
Vol 246 ◽  
pp. 04002
Author(s):  
Harald Taxt Walnum ◽  
Karolina Stråby ◽  
Åse Lekang Sørensen
Keyword(s):  
Water Flow ◽  
Water Consumption ◽  
Energy Demand ◽  
Significant Proportion ◽  
Water Saving ◽  
Building Envelope ◽  
Hot Water ◽  
Comfort Level ◽  
Domestic Hot Water ◽  
The Difference

Domestic Hot Water (DHW) production constitutes a significant proportion of the energy demand of modern buildings, and as the building envelope is improved the share increases. This article shows results from a measurement campaign on two equal hotel blocks, in the same hotel. There are different basin and shower mixing taps installed in the two hotel blocks, one with original mixers (13–14 l/min) and one with touch-free operated water saving mixers (5–6 l/min). The number of guests were registered separately for the two blocks. The results indicate almost a one-to-one relationship between the difference in mixer and total water consumption, resulting in a potential energy saving of 50–60%. There are no indications that the reduced water flow results in increased duration of each individual shower. However, it is not known if this is due to the use of touch-free operated mixers. Feedback through complains from guests indicate somewhat reduced perceived comfort level from the water saving mixers, and some annoyance caused by the touch-free operation. The results indicate that optimal balance between user comfort and water saving is slightly higher water flow than the applied 5–6 l/min.

Performance Characteristics of a Thermosyphon Solar Domestic Hot Water System

1981 ◽  
Vol 103 (3) ◽  
pp. 193-200 ◽  
Author(s):  
M. F. Young ◽  
J. B. Bergquam
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Storage Tank ◽  
Indirect Method ◽  
Hot Water ◽  
Temperature Profiles ◽  
Flow Rates ◽  
Domestic Hot Water ◽  
Mass Flow Rates

Performance characteristics (i.e., system temperatures and mass flow rates) of a thermosyphon solar domestic hot water (SDHW) system that are representative of practical system configurations and sizes are presented. Experimental weather/radiation conditions, collector inlet/outlet temperatures, collector mass flow rates, and storage tank temperature profiles are presented for the same period. These form a consistent set of performance data to which numerical predictions are compared. An indirect method using the storage tank temperatures is used to experimentally determine the thermosyphon mass flow rate. The accuracy of this indirect method is verified by comparison to measurements taken with a turbine flow meter on a pumped SDHW system. System temperatures and mass flow rates are predicted using a general purpose transient SDHW computer program, SHOW (Solar Hot Water). This program contains models for the solar collector, storage tank, and the thermosyphon mass flow rate. The storage tank is modeled as a stratified liquid tank with internode convection and conduction, stored internal energy, heat losses from the tank exterior, and some mixing at the tank inlet/outlet boundaries. Comparisons of predicted collector inlet/outlet temperatures; storage tank temperature profiles, and mass flow rates show agreement with experiments.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

A Design Method for Thermosyphon Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 150-155 ◽  
Author(s):  
M. P. Malkin ◽  
S. A. Klein ◽  
J. A. Duffie ◽  
A. B. Copsey
Keyword(s):  
Flow Rate ◽  
Design Method ◽  
Water Systems ◽  
Hot Water ◽  
Average Flow Rate ◽  
Domestic Hot Water ◽  
Average Flow ◽  
Solar Fraction ◽  
Wide Range ◽  
Flow Circuit

A modification to the f-Chart method has been developed to predict monthly and annual performance of thermosyphon solar domestic hot water systems. Stratification in the storage tank is accounted for through use of a modified collector loss coefficient. The varying flow rate throughout the day and year in a thermosyphon system is accounted for through use of a fixed monthly “equivalent average” flow rate. The “equivalent average” flow rate is that which balances the thermosyphon buoyancy driving force with the frictional losses in the flow circuit on a monthly average basis. Comparison between the annual solar fraction predited by the modified design method and TRNSYS simulations for a wide range of thermosyphon systems shows an RMS error of 2.6 percent.

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