How does an ocean thermal energy conversion OTEC system work?
Ocean Thermal Energy Conversion (OTEC) systems use a temperature difference (of at least 77° Fahrenheit) to power a turbine to produce electricity. The vaporized fluid drives a turbine/generator. The vaporized fluid is turned back to a liquid in a condenser cooled with cold ocean water pumped from deeper in the ocean.
What is the principle of ocean thermal energy conversion?
Working principle OTEC uses the ocean’s warm surface water with a temperature of around 25°C to vaporize a working fluid, which has a low-boiling point, such as ammonia. The vapor expands and spins a turbine coupled to a generator to produce electricity.
What type of working fluids do closed cycle ocean thermal energy conversion OTEC systems use?
Closed-cycle systems use fluid with a low boiling point, such as ammonia (having a boiling point around -33 °C at atmospheric pressure), to power a turbine to generate electricity. Warm surface seawater is pumped through a heat exchanger to vaporize the fluid.
What is the minimum requirement to operate the OTEC system?
Ocean thermal energy conversion (OTEC) utilizes the temperature difference noted between surface and ocean temperatures is 20 degrees.
What are the different types of OTEC?
Ocean thermal energy conversion (OTEC) captures the temperature difference between cooler deep and warmer shallow ocean water to produce electricity. There are three kinds of OTEC systems: closed-cycle, open-cycle, and hybrid. OTEC plants can be based onshore (land-based and near-shore) or offshore.
How is OTEC caused by?
Ocean Thermal Energy Conversion (OTEC) is a process that can produce electricity by using the temperature difference between deep cold ocean water and warm tropical surface waters. OTEC plants pump large quantities of deep cold seawater and surface seawater to run a power cycle and produce electricity.
What does OTEC stand for *?
Ocean Thermal Energy Conversion
Which turbine is commonly used in tidal energy?
Kaplan turbine
What is the efficiency of OTEC?
The low energy conversion efficiency of OTEC means that more than 90% of the thermal energy extracted from the ocean’s surface is ‘wasted’ and must be rejected to the cold, deep sea water. This necessitates large heat exchangers and seawater flow rates to produce relatively small amounts of electricity.
Why is ammonia used in OTEC?
An OTEC power plant works by pulling in warm ocean surface water and this is used to heat a ‘working fluid’ such as ammonia or propane into a gas. These fluids have a low boiling temperature, which when turned into gas, moves the steam into pressurised shafts that are then used to drive turbines.
Who invented OTEC?
Jacques-Arsène d’Arsonval
How would you enhance the efficiency of OTEC system?
Yamada et al.2 reported that the system efficiency of the OTEC power cycle can be increased 1.5-fold if the temperature of the surface seawater flowing into an evaporator with a solar collector will be increased or by providing more superheat to a working fluid that evaporates in an evaporator.
What is closed cycle OTEC?
A closed cycle OTEC system incorporates a working fluid operating between two heat exchangers in a closed cycle. A closed cycle utilizes the warm surface water to vaporize the working fluid in an evaporator. The condensed working fluid is pumped back to the evaporator and the cycle is repeated.
How thermal efficiency of a marine plant is enhanced?
The primary effect of regeneration in a Stirling engine is to increase the thermal efficiency by ‘recycling’ internal heat which would otherwise pass through the engine irreversibly. As a secondary effect, increased thermal efficiency yields a higher power output from a given set of hot and cold end heat exchangers.
What is the efficiency of a diesel engine?
43%
Which two main points are necessary for its working OTEC?
Answer. Answer: OTEC uses the ocean’s warm surface water with a temperature of around 25°C (77°F) to vaporize a working fluid, which has a low-boiling point, such as ammonia. That condenses the working fluid back into a liquid, so it can be reused.
How many types of OTEC plants are there Mcq?
6. How many types of OTEC plants are there? Explanation: There are three types of ocean thermal energy plants. They are closed cycle systems, open cycle ocean thermal energy conversion and hybrid ocean thermal energy conversion.
What are the advantages of OTEC?
The pros are OTEC is fuel free, has a low environmental impact, can supply pure water for both drinking and agriculture, can supply refrigeration and cooling and can provide a coastal community with reliable energy. [1] The cons are that OTEC is economically expensive, and it only works in a few regions of the world.
What are the disadvantages of OTEC?
Disadvantages:
- Capital cost is very high.
- Efficiency of energy conversion is very low.
- Needs very large sized turbines due to use of low pressure of steam having high specific volume in case of open cycle.
- It uses expensive power working fluids in case of closed cycle.
- Cost of electric power generation per kWh is very high.
How much does OTEC cost?
The proposed structure has some portion above the ocean surface. The structure can be assembled in the ocean. The cost of a proposed 50 megawatt (MW, net power) OTEC plant is approximately 75 million dollars.
How much does thermal energy cost?
Thermal Energy Costs
| Energy Source | Average Retail Price | Cost per million Btu |
|---|---|---|
| Electricity | $0.1040 per kilowatt hour | $30.48 |
| Propane | $1.88 per gallon | $20.55 |
| No.2 Heating Oil | $2.37 per gallon | $17.05 |
| Natural Gas | $13.75 per thousand cubic feet | $13.35 |
What are the disadvantages of ocean thermal energy?
Disadvantages of OTEC system
- Capital investment is very high.
- Conversion efficiency is very low about 3-4% due to small temperature difference in between the surface water and deep water.
- Low efficiency of these plants coupled with high capital cost and maintenance cost makes them uneconomical for small plants.
Which is the working fluid in open cycle?
water
Which is the working fluid in open OTEC cycle?
water vapour
What is the difference between open cycle and closed cycle OTEC?
Hybrids of the two have also been proposed. A closed cycle OTEC plant employs a thermodynamic fluid such as ammonia or a refrigerant like freon. This is contained in a completely closed system including the plant turbine. In an open cycle OTEC system the seawater itself is used to provide the thermodynamic fluid.
What is the working fluid in closed cycle MHD system?
The operation of MHD generators directly on combustion products is an open cycle system using air as working fluid. In closed cycle systems gases used on the working fluid are helium or argon.
What is the principle of MHD power generation?
Principle of MHD Generator As the conducting fluid (conductor) moves through the magnetic field, it produces an electrical field perpendicular to the magnetic field. This process of electric power generation through MHD is based on the principle of Faraday’s law of electromagnetic induction.
Which of these is the most promising power generation system?
Geothermal energy