Tag Archives: Mechanical Engineering

California Water Conservation Causing A Sewer & Plumbing Pipe Crisis

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“Shorter showers, more efficient toilets and other reductions in indoor water usage have meant less wastewater flowing through sewer pipes, [California] sanitation officials say. With less flow to flush the solids down the system, those solids are collecting and can eventually damage pipes.”

Sourced through Scoop.it from: www.expresssewer.com

” […]

Less Water Flow Means Greater Pipe Degradation

As home and business owners throughout California use various methods to cut water consumption both in and out of their properties, less water is then available to cycle through sewer systems. Lower sewer flow then makes it difficult for waste materials, oils water and other contaminants to cycle through. Best case scenario, this can result in minor sewer buildup or blockage; worst case, it can cause severe clogging, corrosion and pipe breakage at weak joints.

With corrosion comes increased pipe repair and replacement costs. Otherwise healthy sewer pipes will fail prematurely as clogs and chemicals remain stagnant within pipes.

Decreased water flow due to conservation is a particularly troubling problem in Sacramento, where the municipal sewer system is relatively flat compared to other cities in the state. With a flat sewer system, it is already difficult for water and materials to flow at a normal rate; when this rate is lowered, and gravity cannot help waste and waste water along, there is little to push solid materials along.

The people of Sacramento, in this case, are stuck between a rock and a hard place: water has to be conserved in light of the unrelenting draught, and doing so creates hazards for the entire city sewer system.

Dealing With the Issues

One way Sacramento residents can help reduce the likelihood of sewer clogging during low water flow periods is by changing the way they use their plumbing systems – overall reducing the amount of non-fluid materials that enter sewer systems.

This includes knowing what kinds of things you should not flush or dispose of through the sink, such as:

Baby wipes or other kinds of “flushable” wipes – they’re not really flushable, and actually cause millions of dollars in sewer damage annuallyStarchy food products or peelsAny plastic materials, including wrapping or casesPaper towels

Beyond better flushing practices, also steer clear from using chemicals or commercial drain cleaning products, as these products can eat away at sewer pipes from within, causing extra difficulties for pipes with low-flow or stagnant water. […]”<

See on Scoop.it – Green Building Operations – Systems & Controls, Maintenance & Commissioning

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Maintaining High Performance HVAC Control Systems for Cost Savings in Building Operations

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The performance level of a building is directly related to the performance level of its control systems. You cannot manage a high performance building without high performing control systems.

 

Source: www.automatedbuildings.com

>”We rely on control systems to monitor and manage our building systems. For the most part it’s been assumed that once the control system is installed and configured it will work for years with little attention and minimal maintenance. Some systems may be trouble-free, but the majority of them will need regular attention and maintenance. Over time hardware will fail, software parameters and versions change and slowly the control system will “drift” from its original configuration and performance.

The role of control systems is somewhat undervalued. When you examine the most complex system in most buildings, the HVAC infrastructure, you find that it’s the HVAC control system, not the HVAC equipment, which produces the most operational issues and is the leading cause of inefficient energy use. Lawrence Berkley National Laboratories examined 60 buildings and found the highest frequency of common problems with HVAC was in the control system. Texas A&M research determined that of the operational and maintenance measures that could produce significant energy savings, 77% of the savings were from correcting control problems.

Maintaining a high performing control system involves regular maintenance, software and data management and organizational policies. The issues that can cause problems with a building control system are the same challenges all of us have had at one time or another with our computer or smartphone: problems related to software, hardware, communications networking and “user” mistakes. What follows is an overview of some of the typical control system issues and recommendations as to how to keep it performing at a high level.”<

See on Scoop.it – Green Building Operations – Systems & Controls, Maintenance & Commissioning

The Datacenter & Cloud Computing: Design of Warehouse-Scale Machines

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Clipped from http://www.morganclaypool.com/doi/pdfplus/10.2200/S00516ED2V01Y201306CAC024

“While we draw from our direct involvement in Google’s infrastructure design and operation over the past several years, most of what we have learned and now report here is the result of the hard work, insights, and creativity of our colleagues at Google. The work of our Technical Infrastructure teams directly supports the topics we cover here, and therefore, we are particularly grateful to them for allowing us to benefit from their experience.”

DOE Regulations: Energy Efficiency Improvements for Motors cause Industry Challenges

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The United States has had efficiency regulations for industrial electric motors in place since October 1997, when the Energy Policy Act of 1992 (EPAct 92) set minimum efficiency levels for 1- to 200-hp general-purpose three phase motors. EPAct 92 was upgraded when the Energy Independence and Security Act of 2007 (EISA) went into effect in December 2010.

Duane Tilden‘s insight:

>Several years ago, the U.S. Department of Energy (DOE) conducted a technical study as to what could be done to raise the efficiency levels of “small” motors. After years of study and litigation, the Small Motor Rule was passed that covers two-digit NEMA frame single- and three-phase 1/3 through 3 horsepower motors in Open enclosures.

Although the Small Motor Rule seems simple, it has the effect of creating motors with much larger footprints, particularly on single phase designs where capacitor start/induction run motors may largely be discontinued in Open enclosures. In some cases, a TEFC motor may be more cost effective and smaller than an Open motor.

The DOE is presently conducting another technical study on “medium” AC induction motors of 1- to 500-hp. In their study, DOE is evaluating a possible increase in nominal motor efficiency of 1 – 3 NEMA bands (approximately 0.4 to 1.5%) above NEMA Premium Efficiency levels as defined in MG 1-2011 table 12-12. Although this sounds simple to do, such a motor redesign could entail new laminations, winding equipment and in many cases, new frames to fit the extra material. Some designs may not fit where existing motor designs of the same ratings fit today. This means that OEMs would need to redesign their machine if that is an issue and end users may have trouble fitting the new higher efficiency replacement motor into their equipment or existing envelope.<

See on www.designworldonline.com

Air Conditioning the World stresses Global Energy Supply

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The United States currently uses more energy for air- conditioning than all other countries combined—a sobering statistic from Stan Cox of the Land Institute in Salina, Kansas.

Duane Tilden‘s insight:

>According to the U.S. Energy Information Administration, 87 percent of American households are equipped with air-conditioning, and the United States expends about 185 billion kilowatt hours of energy annually on residential cooling.  […]

Rapid increases in the ownership of air conditioners are already occurring in many developing countries. According to research by McNeil and Letschert, the percentage of urban Chinese households with an air conditioner jumped from less than 1 percent in 1990 to 62 percent in 2003. In 2010 alone, 50 million air-conditioning units were sold in China.  […]

[…] eight countries have the potential to exceed the United States’ yardstick of high air-conditioning usage, because of their warm climates and significant populations. Furthermore, the top three could surpass the United States by substantial amounts: India, China, and Indonesia by factors of 14, 5.2, and 3.1, respectively, if they adopt American standards of cooling.

[…] Several institutions have recently made major technical advances in the design of more energy-efficient air conditioners. For example, developments at the National Renewable Energy Laboratory suggest that efficiency improvements of 20 to 70 percent are possible compared to current models of air conditioners. Changes in housing design and urban planning are also needed […]<

See on www.americanscientist.org

Energy Efficiency Methods in the Cement industry – Part 1: Organic Rankine Cycle

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Thomas B. Gibbons takes a look at the Conventional Rankine Cycle’s application in the cement sector

Duane Tilden‘s insight:

>The first major waste heat recovery (WHR) system in a cement plant was the 15 MW unit installed by Kawasaki Heavy Industries for Taiheiyo Cement in 1982. This was a conventional Rankine Cycle using heat from both the kiln and the clinker cooler. As the benefits became generally recognised within the industry, WHR units, the vast majority of which involved the conventional Rankine Cycle, were installed to provide up to about 30% of the power requirements of the plant. The main sources of waste heat were the exhaust from both the preheater and the clinker cooler and, in some of the developing countries where power outages are not unusual, the WHR system may be the only source of reliable power available to the plant operator.

Improvement in the overall efficiency of cement manufacture has resulted in lower exhaust gas temperatures and this development has provided opportunities for alternative technologies, notably the Organic Rankine Cycle (ORC) and the Kalina Cycle, which are more effective in recovering waste heat from lower temperature gases.<

See on www.worldcement.com

Green Computing – Business migration to Data Centers and the Cloud

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>With the cloud computing scenario, time and power savings mean everything, in these huge scales, running hardly used servers is effectively throwing money away as well as annoying the environmentalists. In this scenario resource scheduling becomes amazingly effective. so we go back to our 5:30pm shutdown, but on this occassion the technology hosting the Virtual infrastructure kicks in, instead of sitting there half used, it will begin to migrate VM’s that no longer require resources to the same host, so although as a whole they may be using quite a lot of resource, it will enable hosts to be powered down and be sat in a ‘power saving’ state awaiting resources requirements to increase and as such power up from their slumber. Again, getting to the scale of this, you could effectively save power on as an example, 100 hosts – these hosts being the beefiest and most cutting edge servers available, are going to have requirements for a large amount of power, effectively turning these off when not used, is a god send to the idea of cloud computing. Why leave the light on in the attic if you have no intention of going there?

So that is effectively how these datacentres work from a green perspective, but from the company utilising this infrastructure, what do they save?

  • Downsize or offset office space.
  • Downsize onsite infrastructure requirements.
  • Expand the ability for users to work remotely (or globally dependent on your requirements)
  • Support the mobile workforce.
  • Reduce consumables use (printing, ink, paper, file storage costs).
  • Reduce hardware (desktop computers/server systems/UPS’s/cabling)


Green Computing – Office365 #greencomputing.

Sustainable Heating and Cooling of Buildings | Leonardo ENERGY

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In many non-residential buildings across Europe, the energy consumed for heating and cooling is more than half the total energy consumption of the building. This is not inevitable. The introduction of simple design concepts and currently available technologies can lead to significant reductions in the energy consumption, operating costs, and carbon emissions of both new and existing buildings.

See on www.leonardo-energy.org

Unclean at Any Speed – IEEE Spectrum

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Electric cars don’t solve the automobile’s environmental problems

Duane Tilden‘s insight:

>Two dozen governments around the world subsidize the purchase of electric vehicles. In Canada, for example, the governments of Ontario and Quebec pay drivers up to C $8500 to drive an electric car. The United Kingdom offers a £5000 Plug-in Car Grant. And the U.S. federal government provides up to $7500 in tax credits for people who buy plug-in electric vehicles, even though many of them are affluent enough not to need such help. (The average Chevy Volt owner, for example, has an income of $170 000 per year.)

Some states offer additional tax incentives. California brings the total credit up to $10 000, and Colorado to $13 500—more than the base price of a brand new Ford Fiesta. […]

There are other perks. Ten U.S. states open the high-occupancy lanes of their highways to electric cars, even if the car carries a lone driver. Numerous stores offer VIP parking for electric vehicles—and sometimes a free fill-up of electrons. Mayor Johnson even moved to relieve electric-car owners of the burden of London’s famed congestion fee.

Alas, these carrots can’t overcome the reality that the prices of electric cars are still very high—a reflection of the substantial material and fossil-fuel costs that accrue to the companies constructing them. And some taxpayers understandably feel cheated that these subsidies tend to go to the very rich. Amid all the hype and hyperbole, it’s time to look behind the curtain. Are electric cars really so green?

It’s worth noting that this investigation was commissioned by the U.S. Congress and therefore funded entirely with public, not corporate, money.  […]

Part of the impact arises from manufacturing. Because battery packs are heavy (the battery accounts for more than a third of the weight of the Tesla Roadster, for example), […] Electric motors and batteries add to the energy of electric-car manufacture.

In addition, the magnets in the motors of some electric vehicles contain rare earth metals. […]

The materials used in batteries are no less burdensome to the environment, the MIT study noted. Compounds such as lithium, copper, and nickel must be coaxed from the earth and processed in ways that demand energy and can release toxic wastes. […]

See on spectrum.ieee.org