An Introduction to Heating Systems

Blog post for Introduction to heating systems
Source

In the last post, we covered the area of HVAC dealing with air conditioning and refrigeration. For today’s blog post, we’d like to quickly go over the other major topic of HVAC industry – heating systems. In geographical areas where temperature fluctuation tends to be quite extreme, a good working heating system is a vital necessity –especially during the colder winter months. The main challenge of heating systems frequently comes from the heat distribution method. There are a couple types of heating system and it is important to take into account their functionality to decide which is the best type for your application.

The first systems we are going to focus on is central heating,  which is the most common heating system in North American residential applications. This system comes with primary heating applications such as a furnace, boiler, and heat pumps. Each heat source is rather unique and uses different methods of distributing heat into the targeted environment. Furnaces use ducts to blow heated air through in order to disperse the generated energy. Implementation of such technology in the USA is controlled by the Annual Fuel Utilization Efficiency where it estimates seasonal efficiency, averaging peak and part-load situations. Boilers utilizes hot water which travels up to radiators and gets circulated around in a system –  so instead of using a fan and ducts, appliances which utilizes boiler as a heat source commonly uses pump to flows the hot water to other parts of the house/building. Since circulation is the most recurring challenge in heating appliances, an optimal pump design must be installed into the system to make sure that the heat is distributed evenly to each part of site. Within central heating there is also heat pump system which works as two-way air conditioner (direct and reverse). During the hotter season, heat pumps work to moving heat from indoor (cooler) to outdoor (higher temperature), and vice versa during the colder months. Heat pumps generally use electricity to move heat from one place to another.

The second heating system utilizes direct heat. Usually direct heat is used to transfer heat /raise temperature in a small targeted area. In the most common cases, the heat output is relatively small. The most common installation nowadays which utilizes this system is gas fired space heaters or electric space heaters (for more modern implementation), whereas the more conventional one would be fireplaces. This type of heating is less effective for an overall building system.

References:

http://smarterhouse.org/heating-systems/types-heating-systems 

Introduction to HVAC Systems

During the past week we’ve talked about challenges, improvements and development of HVAC technology. But taking a step back, what is a HVAC system? Heating, ventilation, air conditioning systems and refrigeration (or known as HVAC&R) is a technology developed to manipulate environment temperature and air quality. The applications of such technology are based on the principles of thermodynamics, fluid mechanics and heat transfer.

HVAC Intro
Source

Commonly HVAC systems are grouped into four main systems starting with the heating and air conditioning split system, which is the most ordinary implementation of residential applications encompassing both inside and outside installations. The application, which can be controlled with a central thermostat, consists of air conditioning system which cools the refrigerant to drop the temperature, and heating system which involves gas furnaces. Ducts used to circulate the adjusted air from both heating and conditioning, with the help of evaporator/fan coils – a terminal unit which is used to provide heating or cooling to the targeted space.

A split system is known for its simplicity, efficiency and low cost.  That being said, the second type (hybrid heat split system) is actually found to benefit over the first one from an energy efficiency standpoint since the application utilizes heat pump systems. With the incorporation of heat pumps, the system is able to pump cooled or heated refrigerant to make both system able to be controlled through electric power. The heat pump is used to move energy using outside surrounding air as an air source for heating and heat sink for refrigeration/conditioning systems.

A duct free split system would benefit the most to be installed at locales where conventional ducts cannot fit or are not directly connected to central control thermostats. No ductwork would be needed in the system, thus enabling flexibility of delivering air directly to the targeted zones. Since the technology allows you to directly zone the cooled air, using ductless technology could improve efficiency, lower operation cost and reduce carbon footprints.

The last system to note is the packaged heating and air conditioning system – which is normally the system that is installed at locales where there is not enough spaces available for  the components of the split system. A package unit has a heating and cooling system combined into one unit,  making it easier to access for maintenance as well as to be conservative on installation space.

References:

http://www.command-air.com/blog/benefits-of-a-packaged-hvac-system/

https://www.servicechampions.net/what-are-the-different-types-of-hvac-systems/

http://www.mitsubishicomfort.com/articles/ductless/5-advantages-of-ductless-cooling-and-heating-systems

Air Conditioning in Automotive

Car AC
                          Source

While the term of air conditioning in relation to automotive might instantly correlate to a system which provides passenger with a comfortable air temperature/environment, HVAC systems also are used for heating and cooling of batteries in such application as well as cooling of the vehicle fuel systems. Thermal management for automotive application isn’t easy though. Many factors have to be accounted for in order to build a dependable cooling system.

While talking about HVAC concerns and challenges which arise in automotive application, the biggest inconvenience commonly comes down to the lack of cold air produces. Mobile refrigeration/air conditioning systems come with quite a few concerns from two sides: the refrigeration side, where it removes heat and injects cold air, and from the electrical side which provides control. From the system, the most common challenges are found in moisture –which would fail the cooling system if present in the air, soiled condenser which would block air flow, and various other mechanical complications which might occurs.

While diagnosing an air conditioning issue, especially if environment temperature seems higher than it should be, there are few conditions that can be looked into including freon leak, failed blower, damaged or failed motor, damaged condenser to the most common problem usually arises from the compressor. Compressor, compressor clutch switch, fuses, wires, fan belt and seal are at the top of the list to be check for functional adequacy. Consequently, with many concerns arising from the compressor side of the system, a good and reliable compressor design must be implemented to avoid unwanted challenges during operation. Design your automotive turbomachinery with SoftInWay! Ask us about the projects that we’ve done in this field and how our turbomachinery development code will be helpful for your automotive and HVAC design, analysis and optimization activities.

References:

http://www.doityourself.com/stry/5-common-car-air-conditioning-system-problems

http://www.aa1car.com/library/ac98.htm 

http://www.agcoauto.com/content/news/p2_articleid/256

http://blog.firestonecompleteautocare.com/ 

HVAC Design for Humid Climates

Blog for HVAC system Humid climates commonly come with the challenge of moisture standards. When HVAC (heating, ventilations, and air-conditioning) systems do not maintain proper moisture conditions/humidity control, it causes damages and defects to the building.

A humid climate is defined as a condition where the average monthly latent load (energy required to remove moisture from the air) of environment’s air is the same or higher than the average monthly energy needed to cool the air during the cooling season. Using air with high latent load easily brings moisture in and accumulates it in building materials.

Maintaining humidity control isn’t an easy task. The HVAC unit has to be able to support a proper pressurization system using dehumidified air to entire the building. In order to provide the right dehumidification, a HVAC system must be able to dehumidify the air that flows across the cooling oil (which means the precise sizing of cooling coil must be selected to meet the load of both outside and return air). That is not the only criteria that an HVAC system needs to fulfill though. The system must also meet the sufficient run time to remove moisture from the interior air. In a humid condition, temperature control is not enough. Moisture control comes second on the priority list ( though this has to be fulfilled without scarifying the main goal of giving comfortable temperature to users).

In geographical areas with humid weather, such as in the southeast, public housing generally uses chilled water and direct expansion for the cooling system. This requires an outdoor condenser unit to exchange heat to the outdoor air.

Reference:

http://www.greenseal.org/Portals/0/Documents/IG/PHA%20Manuals/Chapter2_Southeast_Green_Building_OM_Manual_PHA.pdf
http://www.tandfonline.com/doi/abs/10.1080/01998590309509232?journalCode=uene20

What’s the Biggest Problem in the HVAC Industry?

HVAC in the Sky with DiamondsWhen asked about problems rising in the HVAC industry, people typically point to the availability of trained workers or labor force. The growth of the HVAC industry brings more open jobs into the market. According to a report by U.S Department of Labor, by 2020, this particular market should bring about 90,000 new jobs in the industry. With that being said, the spike in work doesn’t necessarily align with quantities of qualified workers. Even with strong job security and above average pay, HVAC doesn’t seem to attract too much young potential. In the past year, the HVAC industry has lost thousands of workers, not only from the lagging economy, but also due to the work force available. Currently, the average age of the entire 7.5 million HVAC workforce is around 55 years old, which is much older than the normal workforce.

With the rate of how quickly technology in the HVAC industry is currently growing, the pool of talent in the market can’t quite seem to catch up. Day by day due to increasing demand and competition, leading companies in this industry is required to come up with new design and new technology with better efficiency, easier operation, and better control is needed. Demanding increase in technology does not meet with the current available skill pool. As a result, the hiring process for skilled labor takes considerably longer. Finally, once you take into account calculation of training and orientation, the entire hiring process requires a lot of investment both in time and money.

Technology companies seems to spend most of their available budget on research and development activities. It’s important to pay attention into this particular trend since a high bleed could really impact on the cost of production. During this difficult time of short talents, it makes sense for companies to source out their research and development activities. Our R&D engineering team consists of consulting experts who have completed extensive projects on the subject. We’d be more than happy to assist you with any project needs.

References:

http://contractingbusiness.com/residential-hvac/where-have-all-qualified-hvac-workers-gone
http://contractingbusiness.com/rant/solving-hvac-industrys-biggest-problem
https://www.quora.com/What-are-the-most-important-problems-facing-the-HVAC-industry 
https://www.quora.com/What-are-the-challenges-in-HVAC-field

Outlook for the Future HVAC Market

HVAC image 1
Source

According to the new market research report, the industry of heating, ventilation and air conditioning (HVAC) is predicted to rise at a solid, stable compounding annual growth rate of 5.9% up to the year 2022. With the growing trend of smart homes and changing weather conditions, cooling equipment is expected to remain the largest major share of the entire HVAC market taking around 70% of the entire market totaling to a prediction of 24.28 Billion USD  – including coolers and room air conditioners.

With global warming and increased temperatures taking effect, demand for cooling systems continues to rise in geographical areas where weather is a significant factor, such as Asia Pacific. Countries such as China, Japan and India are significantly driving the growth of this market, as the automotive air conditioning sector plays an important role in these geographical areas as they are still the leaders of the automotive manufacturers by volume.  Rise in middle income (and improvement of environmental standard) in developing countries also push the construction boom and replacement of older technology in air conditioning.

HVAc Image two
Source

Though it’s a positive outlook on the market, increasing demand also leads to tougher competitions. Many new technologies have been introduced in the market, from thermally-driven chiller that provides lower cost alternative to electrical air conditioning units, better sensor control, new software for energy monitoring and improved insulation technologies.  The main factors which influence air conditioning efficiency and economic feasibility are still the refrigeration cycle and compressor component itself. With improvements of compressor mechanisms for less noise and less energy consumption, a slight improvement on blade design or incorporation of more compressor stages to save energy could go along the way.

References:

  1. http://www.grandviewresearch.com/industry-analysis/hvac-equipment-industry 
  2. https://www.thisoldhouse.com/ideas/air-conditioners-really-are-getting-better

The Future of Nuclear Power Plants

With the blast of the French nuclear power plant a few weeks ago, safety of nuclear power plant designs has fallen under more scrutiny. Although according to sources the blast took place in the turbine hall and no nuclear leak was found, this event has brought more attention to improved design and operation standards.

Following the incident earlier this month Toshiba, a Japanese multinational company, announced the resignation of its chairman following a $6.3 billion loss in their nuclear sector –also withdrawing from the nuclear business. The two back to back events have highlighted the main two problems of nuclear power: high cost and environmental/safety concerns. Said to be a green technology, nuclear power raises concerns with potential nuclear meltdown and risk of safety from toxic waste, accompanying the fact that building a new plant cost around $5,000.00 per kilowatt of capacity with around 6 years of lead time. Each dollar invested on a nuclear power plant has about 2-10 less carbon savings and is 20-40 times slower compared to other alternatives. Yes, evidently nuclear power is found to be very reliable, enabling consistent baseload energy production at any time of day and night. Though, it has been questioned whether this reliability is worth the high cost of nuclear production, in fact all nuclear plants are still operating with 100% subsidized.

Transatomic power, a company started by two MIT PhD candidates, came up with a new approach to safer and cheaper nuclear reactors. Utilizing molten salt reactors, which has not really been used commercially and so far is only existed in paper, the technology is promised to cut initial cost and increase safety. Today’s conventional nuclear reactor is cooled by water, due to the high operating temperature, failure to do so will open the risk of radiation leak as well as hydrogen explosion. The high boiling point of salt helps solve some of the problems associated with the technology. The new design also incorporates ways of producing faster neutrons, enabling the reactor to burn most waste materials, thus keep waste to minimum. The ability of this smaller unit to be made in a factory (and not onsite) as well as cost reduction on the safety side makes this attractive economically as well. That being said, this generation 4 nuclear reactor is still in design and development will take years and high capital cost.

References:

https://www.nytimes.com/2017/02/14/business/toshiba-chairman-nuclear-loss.html?_r=0

http://fortune.com/2017/02/16/toshiba-nuclear-power-plants/

Double Flash System Application in Geothermal Power

Geothermal power market has been showing sustainable growth globally, with many installations in developing countries. As people turn to renewable sources while demand for energy is experiencing rapid growth, geothermal is found to be a reliable energy source and current development is calculated to increase global capacity by over 25%. Geothermal power plants can usually be divided into several types of cycles, including binary, flash, double flash and more. Flash power plants are found to be the most common forms of geothermal power plant and specifically, we are going to talk about the double flash cycle.

A flash system produces high pressure dry steam to move the turbine, generating electricity after going through a flash separator. A double flash system uses two flashes separating systems in order to generate more steam from the geothermal liquid and increase cycle output. The cycle starts with high temperature fluid extracted from a geothermal source to a high pressure separator (HPS) for flashing. The HPS produces a saturated steam that enters the high pressure turbine and the remaining brine is directed into a secondary low pressure separator (LPS). Reducing the flashing pressure increases the mixture quality in the LPS, which results in higher steam production. Low pressure saturated steam is mixed with the steam flow exhausted from the high pressure turbine and the resulting steam flow is directed to the low pressure turbine and produces more electricity. Steam that is exhausted from the low pressure turbine will then be compressed and injected back to the ground. In a flash system, separator pressure has a significant effect on the amount of power generated from the system – and the flashing pressures also influence double flash cycle significantly. In order to optimize one design, the value of parameters versus cost of operations should be taken into account.

A double flash system is able to achieve better energy utilization than a single flash cycle, which means that the application has a higher efficiency. At the same geofluid conditions, double flash systems are able to give you a higher capacity. That being said, since this is a more complex system the application of such technology would not be economically feasible for some applications.

References:

http://www.doiserbia.nb.rs/img/doi/0354-9836/2016%20OnLine-First/0354-98361600074L.pdf

https://www.geothermal-energy.org/pdf/IGAstandard/SGW/2013/Pambudi.pdf

https://www.geothermal-energy.org/pdf/IGAstandard/WGC/2010/2612.pdf

The Feasibility of Bringing Back Coal

Power generation and energy sectors happen to be very politically volatile. With our new leader in the USA taking control, we are expecting a shift in technology trends. The topic of bringing more coal fired power plants back to the equation has been brought up quite often, coming after Trump’s skeptical statement regarding global warming and climate-change. To follow that statement, Donald Trump pledged to lift restriction on US agencies funding new coal plants in other parts of the world. In addition, Australia’s minister also has been arguing regarding adding new coal power plants into the mix. As world’s largest coal exporter, it should economically make sense for Australia to forego with the plan.

There are three major categories that typically determine whether a technology would be suitable to be implemented: cost to public, reliability of supply and environmental impact. The old coal power generator is found to be less reliable as well as less environmentally friendly. Consequently, a new technology must be used to provide “cleaner” energy from coal. Southern Company has become one of the first private sectors using new technology to produce energy from coal.  The technology is said to be generating electricity while at the same time capturing carbon dioxide from coal. Maybe if this technology is implemented, we will come back to coal.Power Plant

That being said, what is clean coal technology? Coal is currently known to be the biggest enemy to environment, however clean coal seeks to reduce emission. Before burning the coal, some technology purifies the coal to remove unwanted minerals. Then control the burning to minimize the harsh emission, installing wet scrubbers or desulfurization systems, electrostatic precipitators and Low NOx burners among many other processes.

There are two main problems with clean coal: unproven and expensive. Operating cost for Southern company quadrupled to about $1 billion from the original estimate according to a report. Not only that, the initial cost of investment of this power plant is also two times over budget. Not to say that the same case would be applied to other clean coal power plant, but at the time being, installation of this technology is expensive. Until this could be studied further, seems like cost would be hovering well above standard normal. Another downside is that coal plants are inflexible. While they do give a very constant supply of power, they can’t easily increase or decrease supply –and when they do, it’s economically unreliable. This doesn’t eliminate the chances of coal making a comeback in the future, however, for the time being coming back to coal seems unreasonable since the renewables seems to be making a very positive growth towards the future.

References: 

https://www.theguardian.com/commentisfree/2017/jan/24/no-new-coal-is-not-feasible-on-price-reliability-or-emissions

http://www.bloombergquint.com/technology/2017/01/27/after-2-6-billion-writedown-clean-coal-giant-set-for-opening

The Future of Combined Cycle

In modern days, power generation planners are faced with the challenge of pushing out the most energy from fuel while at the same time minimizing cost and emission.However, finite fuel also generates mass concerns regarding the reserve left to be used in nature. Consequently, people are continuously looking for an economical and highly efficient solution.

To this date, combined cycle gas turbine applications are found to be the best solution to the problem. The application is known to be highly efficient, have favorable energy conversion rates, comparatively lower start up time compared to conventional steam cycles and able to squeeze more power from the same amount of fuel.

countriesOver the past decade, the use of combined cycles has taken over most of the power generation industry. Triggered in the 1990s by the higher costs and environmental concerns of coal power plants, people starting to look for an alternative to cover demands in energy. At the time natural gas seems to be the most logical substitute.

With the increase of renewable energy application, the demand for combined cycles also increases and helps offset the fluctuations of renewable technology. Combined cycle power plants are also found to emit significantly fewer greenhouse gasses compared to most traditional power plants. With this in mind, the use of combined cycle power plants has substantially reduced the amount of emission.

Due to all of the advantages of CCGT mentioned above and more–not to mention the low installed cost, fuel flexibility, flexible duty cycle, and short installation cycle,  investors find combined cycle implementation to be attractive. According to Black & Veatch, natural gas-fired generation is projected to add 348,000MW to U.S grid, where most (if not all) of it will be supplied by a combined cycle generation.

Interested in optimizing your combined cycle plant? AxCYCLE  should do the trick!

 

Reference:

http://www.power-eng.com/articles/2014/02/a-report-on-combined-cycle-projects-in-north-america.html

https://powergen.gepower.com/content/dam/gepower-pgdp/global/en_US/documents/technical/ger/ger-4206-combined-cycle-development-evolution-future.pdf