Cogeneration. Thermal Chillers. and. .. ASHRAE National Capital Chapter. Arlington, VA 10/10/2012

Transcription

1 Cogeneration and Thermal Chillers.. ASHRAE National Capital Chapter. Arlington, VA 10/10/2012

2 Agenda Cogeneration Interest and Application Basics Equipment Matching Thermal Chiller Overview Steam Components & Turbines

3 Definition Cogeneration / Distributed Energy Generation of electrical power on a users site to provide/supplement utility power, by the use of natural gas, coal, oil, wood products, etc., as an energy source.

4 A. Basic CoGeneration Fuel Source Boiler Steam Steam Turbine Generator B. OR Fuel Source Engine Generator

5 Fuel Application 1. What fuels could be used for Example A? 2. What fuels may be used for Example B? 3. Which example is most efficient in changing Fuel BTU s into KW? 4. Which should be used for a given site?

6 Definition Combined Heat & Power (CHP) Cogeneration with heat recovery, designed to achieve a useful thermal balance with the combined power generation and heat recovery. Topping Cycle (Brayton Cycle)

7 The Executive Summary August 2012 Publication Combined Heat and Power A Clean Energy Solution

8 Combined heat and power (CHP) is an efficient and clean approach to generating electric power and useful thermal energy from a single fuel source. Instead of purchasing electricity from the distribution grid and burning fuel in an on site furnace or boiler to produce thermal energy, an industrial or commercial facility can use CHP to provide both energy services in one energyefficient step. The average efficiency of power generation in the United States has remained at 34 percent since the 1960s the energy lost in wasted heat from power generation in the U.S. is greater than the total energy use of Japan.

9 CHP captures this waste energy and uses it to provide heating and cooling to factories and businesses, saving them money and improving the environment. CHP is a commercially available clean energy solution that directly addresses a number of national priorities including improving the competitiveness of U.S. manufacturing, increasing energy efficiency, reducing emissions, enhancing our energy infrastructure, improving energy security and growing our economy.

10 While CHP has been in use in the United States in some form or another for more than 100 years, it remains an underutilized resource today. CHP currently represents approximately 8 percent of U.S. generating capacity compared to over 30 percent in countries such as Denmark, Finland and the Netherlands. /pdfs/chp_clean_energy_solution.pdf

11 District Energy. org The International District Energy Association (IDEA) commends the White House for issuing an Executive Order, "Accelerating Investment in Industrial Energy Efficiency," which calls for greater deployment of combined heat and power (CHP) as a means to increase energy efficiency, reduce energy intensity and strengthen US manufacturing and industrial output.

12 IDEA President & CEO Robert Thornton stated, We applaud the Administration s leadership in urging our industry to work together to add 40 gigawatts of new CHP capacity by CHP is a proven, cost effective approach to harnessing both useful heat and power from a single fuel source, leading to higher efficiencies, lower energy costs and reduced emissions a triple win for the US economy.

13 ACEEE American Council for an Energy Efficient Economy September 19, 2012 Combined Heat and Power Could Replace up to 100% of Retiring Coal Plant Capacity in States across the Country Coal powered generation is becoming increasingly uneconomic due to several factors: the increased cost of coal; the decreased cost of alternatives like natural gas; an aging and inefficient coal fleet; and the impact of new and forthcoming air quality regulations, which aim to reduce toxic pollutants and other substances harmful to human health and the environment. An estimated 2 to 5 percent of U.S. electric generating capacity will retire due to the above impacts, most of it in the form of older and smaller coal plants that were built over two generations ago.

14 Back to Basics CHP = Energy usage to the OINK

15 Where will the Energy for CHP come from? Coal? Oil? Gas? Wood? All of the above, and more.

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17 ASHRAE Publications Application Guide for Absorption Cooling/ Refrigeration Using Recovered Heat Product Code Cogeneration Design Guide Product Code Fundamentals of Steam System Design Product Code 98030

18 Combined Heat & Power -- CHP -- Design Principle: A Generator is a 60% Efficient Boiler with Free Electricity

19 Technology Match Power Generation / Thermal Cooling Distributed Generation Technologies Thermally-Activated Cooling Technologies Solid Oxide Fuel Cell 800ºF 600ºF Steam Turbine Centrifugal Chiller Turbine Generator Gas-turbine I.C. Engine - Jacket / Exhaust - 360ºF Double-Effect Absorption Chiller Microturbine - Exhaust - 190ºF Single-Effect Absorption Chiller Desiccant Technology I.C. Engine - Jacket / Exhaust - 19

20 CHP Prime Movers Combustion Turbines MW Microturbines kw IC Engines 30 kw 5 MW Fuel Cells 200 kw 1 MW 65% 50% WASTE HEAT 25% 40% Electricity 20

21 Combustion turbines (CT) provide high volume, high quality heat and are typically over 1 MW in size providing the most thermal energy volume to 6130 KW Busbar Output $ 1,600,000 to $ 5,600,000 Installed Cost Internal combustion engines (IC) provide high volumes of medium quality heat. 240 to 4750 KW Busbar Output $ 230,000 to $ 2,900,000 Installed Cost Micro turbines (MT) provide high volumes of low quality heat and are grouped together to provide sufficient waste heat. 50 to 300 KW Busbar Output $ 120,000 to $ 550,000 Installed Cost

22 Selection of a generator - is often dependent on the characteristics of a technology at a particular size all systems suffer a loss of efficiency as the size is reduced. Large CHP sites (over 1 MW) generally use combustion turbines. Medium sites (250 kw 2 MW) use IC engines predominantly. Small sites under 250 kw required output use either IC engines or microturbines.

23 Generator Thermal Output Simple Cycle Combustion Turbine: High Volume, High Temp Exhaust ( F) Recuperated Microturbine: High Volume, Medium Temp Exhaust ( F) IC Engine: Low Volume, High Temp Exhaust ( F) + Hot Water ( F) Fuel Cell (SOFC): Low Volume, Medium Temp Exhaust ( F)

24 Break Period Next Thermal Chillers

25 Steam Turbine Chillers High & Low Temperature Activation, F High & Low Pressure Steam System, psig High Efficiency 700 to 5,000 Tons Efficiency 1.25 COP, Compact footprint High IPLV Efficiency 1.8 COP Condenser Water 3 GPM, 55 F Chilled Water to 36 F 25

26 Absorption Chillers Single Effect: Low Temperature Activation, F Steam or Hot Water Low Cost Simple Good Efficiency 0.71 COP Double Effect: High Temperature Activation, 350 F Steam or Direct Fired Higher Cost More Complex High Efficiency 1.3 COP Wide range of models from <100 tons to >1,500 tons Chilled Water down to 38F 3.3 to 4.5 GPM Condenser Water, < 70 F Large & Heavy, Slower Response 26

27 Footprint - Two-Stage Absorber Chiller vs. Centrifugal Chiller Example 1,500 Tons (3,500 kw) Two stage absorption chiller is about 360 ft² (33.4 m²), 115,000lb (54430kg) Centrifugal steam turbine chiller 190 ft² (17.7 m²), 84,000lb (38,180kg) Equals 90% larger footprint, and 37% more weight for absorption 30 ft 10 ft Steam Turbine Centrifugal Absorption 12 ft 19 ft

28 Part Load Efficiency IPLV 1.8 IC Engine Efficiency (COP) IPLV 1.5 Steam Turbine Double Effect Absorber IPLV 0.9 Single Effect Absorber Percent Load

29 THERMAL CHILLERS COP SITE COP SOURCE Absorption Chillers Single stage Two stage direct fired Two stage steam fired Steam Turbine Driven Centrifugal Chiller Gas Engine Driven Centrifugal Chiller ELECTRIC CENTRIFUGAL CHILLER COP SITE COP SOURCE Electric motor driven centrifugal

30 CHP Plant Size Average output of a based CHP plant. Electric efficiencies vary for each generator type but do not impact CHP efficiency CHP System Thermal Technology Effective Size Range CHP Output Efficiency HHV ISO Electric Output Chilling 44 F & 83 F Nominal Electric Efficiency LHV Configuration Model kw % kw Tons % Large Combustion Turbine CHP Turbine % 4, % Small Combustion Turbine CHP Dbl Abs % 1, % Lg. Microturbine CHP Dbl Abs % % Lg. Reciprocating Engine CHP Dbl Abs % 2, % Sm. Reciprocating Engine CHP Slg Abs % 1, % Sm. Microturbine CHP Slg Abs % % CHP Output Efficiency = (Total busbar kw + Cooling converted directly to kw) / Fuel Input (HHV) 30

31 CHP Efficiency CHP Output Efficiency is generally higher for Combustion Turbine based CHP system than IC Engine based systems. CHP System Thermal Technology Effective Size Range Thermal-Electric Ratio CHP Output Efficiency HHV Configuration Model kw T/kW % Large Combustion Turbine CHP Turbine % Small Combustion Turbine CHP Dbl Abs % Lg. Microturbine CHP Dbl Abs % Lg. Reciprocating Engine CHP Dbl Abs % Sm. Reciprocating Engine CHP Sgl Abs % Sm. Microturbine CHP Sgl Abs % CHP Output Efficiency = (Total busbar kw + Cooling converted directly to kw) / Fuel Input (HHV) 31

32 Gas Heating Values Low Heating Value (LHV) Excludes the latent heat of condensation High Heating Value (HHV) Includes the latent heat of condensation LHV = 0.9 x HHV

33 CHP with Recovered Hot Water Exhaust Ambient Air Jacket Water HR Building Air Handling Unit s IC Generator with Jacket Water Heat Recovery Water Return Chilled Water Single Stage Absorber Hot Water

34 CHP with Recovered Med. to Low Pressure Steam or Hot Water Heat Recovery Steam or Hot Water Generator Exhaust Duct Burner Exhaust HR Ambient Air Jacket Water HR Building Air Handling Unit s IC Engine Generator with Jacket Water and Exhaust Heat Recovery Chilled Water Two Stage Absorber or Single Stage Absorber Condensate / Water Return Steam or Hot Water

35 CHP with Recovered Steam Combustion Turbine Inlet Air Cooling Heat Recovery Steam Generator Exhaust Duct Burner Ambient Air Building Air Handling Unit s Combustion Turbine Chilled Water Generator Steam Turbine Chiller or Two Stage Absorber Steam Condensate Steam

36 Combustion/Gas Turbine CHP System EXHAUST BYPASS SILENCER DIVERTER VALVEs AIR INLET FILTER GENERATOR GAS TURBINE HEAT RECOVERY STEAM GENERATOR (HRSG) SUPPLE MENTARY BURNER PROCESS STEAM

37 Gas Turbine Inlet Air Cooling

38 University Application High Efficiency CHP System with High Thermal Output Cooling Towers Steam Turbine Chillers Inlet Air Cooling Combustion Turbine Generator Bypass Stack Heat Recovery Steam Generator Main Stack Duct Burner Dump Condenser Steam Supply Fuel Supply Chilled Water Supply/Return Steam Heat Supply/Return Condensate Return Fig. Taurus 60 / Steam Turbine CHP System 38

39 2800 Steam Turbine Centrifugal

40 CHP with Recovered Steam Combustion Turbine Inlet Air Cooling Heat Recovery Steam Generator Exhaust Duct burner Ambient Air Engine Driven Centrifugal or Direct Fired Absorber Chilled Water CT Combustion Turbine Generator Steam Turbine Generator Steam Condensate Steam

41 Break Period Next Steam Components & Turbines

42 Turbine Talk Exhausting Turbines / Back Pressure Positive Pressure Exhaust Condensing Turbines Negative Exhaust Pressure Common Applications (rotating equipment) Generators, Chillers, Pumps

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44 Steam Exhaust 112 F Condensing Turbine Steam Inlet 375 F

45 Nozzle Valves Lower Arc of Emission

46 Turbine Section

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49 End-milled diaphragm (stationary segment), without vanes

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51 Condensing Turbine Steam System Exhaust Trunk Air (at start) Wet Steam Vacuum Pump Surface Condenser Turbine Speed Level Steam Supply Condensate Pump Condensate Return Page 51

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53 Steam Surface Condenser Exhaust Steam Condensate Out Cooling Water In Condenser Pump Level Control Vacuum Pump

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