Lecturer: Hongqiangli

Email:lihongqiang2009@yahoo.com.cn

2

Lesson two

Energy Utilization and Conservation in Buildings

Energy (classification, utilization principles etc.)1

Energy consumption in buildings2

History of energy saving in buildings33

Technical status and development trend44

35 Text learning and key words

Topics

Energy Utilization and Conservation 能源利用与节约

nonrenewable energy 不可再生能源 renewable energy 可再生能源 solar energy 太阳能 hydropower 水力发出的电力geothermal energy 地热能 electrical power 电能steam turbine 蒸汽轮机 mechanical power 机械能energy efficient system 高能效系统 cost effectiveness 成本效率chilled water 冷冻水 condenser water 冷却水ground source heat pumps 地源热泵

Energy Utilization and Conservation 能源利用与节约

nonrenewable energy 不可再生能源 renewable energy 可再生能源 solar energy 太阳能 hydropower 水力发出的电力geothermal energy 地热能 electrical power 电能steam turbine 蒸汽轮机 mechanical power 机械能energy efficient system 高能效系统 cost effectiveness 成本效率chilled water 冷冻水 condenser water 冷却水ground source heat pumps 地源热泵

Frequently used words and phrases

• Energy definition

自然界赋存的已经查明和推定的能够提供热、光、动力和电能等各种形式的能量来源 .

• Energy definition

自然界赋存的已经查明和推定的能够提供热、光、动力和电能等各种形式的能量来源 .

• For instance• Coal, natural gas, crude oil, wind, hydropower, tidal energy, nuclear, biomass, geothermal, coal bed gas, wave energy, Ocean current energy, solar and so on…

• For instance• Coal, natural gas, crude oil, wind, hydropower, tidal energy, nuclear, biomass, geothermal, coal bed gas, wave energy, Ocean current energy, solar and so on…

Topic one: Energy-Definition

6

Nonrenewable energy

Renewable energy

Coal

Crude oil

Natural gas

Solar energy

Hydropower

Wind energy

Geothermal energy

Biomass energy

Tidal power

Two broad categories

Topic one: Energy- Classification

7

The First Law of Thermodynamics (formula and equation)

The Second Law of Thermodynamics

Topic one: Energy- utilization principles

1824年，卡诺揭示了热机的科学本质，奠基现代工程热力学

热力循环（热机）

燃料

燃烧

传热

~

发电

热转功

1768年，瓦特发明蒸汽机

作功能力损失巨大

Rankinecycle

Topic one: Energy- development status and trend

0

0. 1

0. 2

0. 3

0. 4

0. 5

0. 6

0. 7

0. 8

0. 9

1

0 200 400 600 800 1000 1200 1400

作功能力损失巨大

Rankinecycle

Braytoncycle

400~600oC

环境温度

20~60年代效率20~40%

卡诺定理为基础，热能的温度对口、梯级利用热能的温度对口、梯级利用是 19世纪热力循环研究的主线主线

900~1400oC

60～ 90年代联合循环效率40~60%

热力循环效率

燃料作功能力损失

仍然很大

存在的问题

问题 1：初温提升潜力小，品位差大，可用能损失30%问题 2：污染物 (CO2)

生成并被稀释，处理能耗高

难点卡诺定理无法解释无法解释燃料化学能转化与释放过程不可逆性，缺乏缺乏相关理理论论

CO2分离过程（能耗）与能量利用过程（效率）相互矛盾相互矛盾，难以协调

针对难点，寻找突破思路

Topic Two: Energy Consumption in Buildings-Status

EnergyEnergy

EnvironmentEnvironment

EconomicEconomic

Buildings:

Consumes 20-40% of the Global Resources

Consumes 30-45% of the Energy used

Building energy conservation is the most direct and promising way

Building energy conservation is the most direct and promising way

Large Industry Sectors ： Industry/Communication/Building

11

There are many opportunities for saving energy in cities and strategies can be classified by four major categories.

• (1)Technical Strategies

Technical strategies involve either new energy saving technologies or retrofitting existing technologies. Such changes often require considerable capital investment and can produce significant savings even in the short term. The implementation of technical strategies therefore is often limited by the availability of financial assistance such as grants or low interest loans.

• (2)Regulatory Strategies

Regulatory strategies are based on the introduction of local laws or regulations such as building codes or energy efficiency standards. These strategies pass most of the costs on to the users, but regulatory authorities must administer and enforce them.

Topic Two: Energy Consumption in Buildings-Status

12

• (3)Economic strategies

Economic strategies involve incentives or penalties, which create a climate for energy efficiency. They can include ‘no regrets’ or voluntary measures as well as tax credits for energy efficiency and renewable energy research investment. These strategies are more costly for government, but they are generally more popular with industry and the public. In some cases economic strategies can generate considerable income by imposing taxes on fossil fuels or excessive energy use. Such taxes may be directed into the development of technical and education strategies for further energy savings.

• (4)Education strategies

Education strategies involve the use of education, training and information to raise awareness about alternative energy systems and energy efficiency. It is a powerful agent of social change and can produce substantial energy savings for a minimal cost. Typical measures include driver training and raising public awareness of energy savings options. Education and training is also important for sales people, maintenance personnel and consumers.

部分重整

降低重整温度，初始反应物浓度，加快了反应速率，减少重整耗热，降低本身△ G的降低

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C h a ra cte rs

Policy Technology Economic EducationSolutions

IntegratingIntegrating

Based on laws;

Pass cost on users;

enforced

Require capital inve-

stment; short term

effect; Limited by

financial

assistance, etc.

Incentives or penalties;

Costly for government;

Popular with industry

and Public, etc.

Powerful, substantial

energy saving with

minimal cost; For

various groups

Topic Two: energy consumption in buildings-Solutions

Topic Three: History of building energy saving-Three stages

Energy saving in buildings

Energy conservation in buildings

Energy efficiency in Buildings

Developmentprocess How about the difference?

Topic Three: History of building energy saving-Three stages

Character

Limit the energy demand, eg. Increasing/ lower the temperature

Character

Keep the heat or cool in the room, eg.Improve the envelop (double glass, lower air infiltration etc. )

Character

Improve the energy efficiency, eg. increase the thermal efficiency, optimize HVAC operating etc.

conservation

efficiency

saving

Traditional Design Process

Schematic Design/Architectural Design

Programming

Engineering Design (Construction)

Engineering Design (HVAC and Indoor Climate)

Construction

Operation and Maintenance

Demolition and Reuse

Building Owner/Architect

Building Service Personal

Architect

Engineer Construction

Contractor

Engineer HVAC

Building stages Involved persons

Topic Four: Technical status and development trend-The building design itself

Integrated Design Process

ProgrammingBuilding Owner/Architect

Building Service Personal

ArchitectEngineer Construction

Contractor

Engineer HVAC

Construction

Operation and Maintenance

Demolition and Reuse

Schematic Design/Architectural Design

Engineering Design (Construction)

Engineering Design (HVAC and Indoor Climate)

Construction/Operation/MaintenanceDemolition/Reuse

Building stages

Integrated Design Process

Involved persons

Some technology ideas for energy conservation

Air conditioning system realize optimized operation, reduce operating cost (energy and money).

Adopt advanced equipments and techniques. (lights) Recovery afterheat and waste heat Change the energy supply resources Make use of novel energy generation systems. (DES)

18

Topic Four: Technical status and development trend—— building equipments and energy supply

CallDES

development

Renewable energy ： sustainable energy， dispersion small scale

Energy supply safety ： Meet consumers demand multi-power supply

Cool, heat and power needed in buildings ： CHP Transportation in short distance CCHP

DES is very significant to realize energy sustainable development

Further energy development trendFurther energy development trend

Why should we develop DES (Distribute energy system)

DES can realize cascaded utilization of energy

Gas turbine

Absorption

Dehumidify &heating

Afterheat（ 300~500℃ ）

Afterheat（ 100~200℃ ）

Elec19

Cool46

Heat14

80

N-G

Er20%

Elec

Drive heat pump

Drive cooling

Dehumidify

Living water

Heating

GradeFUELS

High T

Middle T

Low T

Solar

Geo-thermal

N-G

100

57

27

16

Compression

Gas-fired boiler

Power pool

Individual systemIndividual systemDESDESHeat （ 900~1100℃ ）Heat （ 900~1100℃ ）

ConsumerConsumerConsumerConsumer

Case study

Light pipe outside Light pipe inside

Sun visor system

Sun visor system Sun lights

Guess it ? Wood and plastic floor

Crystals silicon solar

Amorphous silicon solar

Amorphous silicon solar

Planting in buildings

Wall or window?

Construction materials

Construction materials

32

If you succeeded , there must be some experience, while if you failed, there must be reason. Anonymous

Topic Four: Technical status and development trend——Barrier

Nearly all the live people in China are studying or working for Mao Ze-dong. Hong-qiang Li

33

While many efficient technologies cost more to purchase, energy savings often more than repay the extra capital cost. The financial returns offered by these technologies are typically far better than those offered by other personal financial investments.

Technology Typical Payback (years)Additional insulation 6 - 7Compact fluorescent lamps Less than 2Condensing gas furnace 4-7Electronic ballasts for commercial lighting 3-4Improved burner head for oil furnaces 2-5Residential duct repair Less than 2Highly efficient room air conditioner 6-7Water heater tank insulation Less than 1

Topic Four: Technical status and development trend——Barrier

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If cost-effective technologies are available, why aren’t they in greater use? The reasons as follows:

① There is often a separation between those who purchase energy-using equipment and those who pay to operate the equipment, which undermines existing incentives for efficiency.

② Decisions on purchasing energy-using equipment require comparisons across many attributes, such as first cost, performance, appearance, features, and convenience. These other attributes often overshadow energy efficiency considerations.

③ Very few pursue the goal of minimizing life-cycle costs (the sum of capital and operating costs over the life of the equipment), which energy efficient technologies achieve.

Topic Four: Technical status and development trend——Barrier

35

④When trading off initial cost and energy savings, consumers will not invest in efficiency unless it offers very short payback periods-less than 2 years for home appliances, for example. In contrast, personal financial investments generally offer much lower returns.

⑤ Energy costs are relatively low (about 1 percent of salary costs in a typical office, for example), so those concerned with cost reduction often focus elsewhere.

⑥ Energy efficiency is often misperceived as requiring discomfort or sacrifice, limiting its appeal.

Topic Four: Technical status and development trend——Barrier

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1. Introduction

The situation of energy utilization at present, and why we should conserve energy

2. Energy resources

two broad categories: nonrenewable & renewable

3. Principles of energy utilization

First and Second Laws of Thermodynamics

4. Energy conservation methods

six methods applicable to existing system

5. Measuring the efficiency of energy use in HVAC systems

How to measure? three common elements of the calculation

6. An example of energy conservation analysis

Topic Five: Text learning and keywords

37

1. Costs for energy used in building operations have become such a significant expense that it is necessary that they be kept to a minimum level.

2. From the standpoint of energy conservation, the energy resources that are available for HVAC system operation can be classified in two broad categories — nonrenewable resources and renewable resources.

significant: 数量巨大的

From the standpoint (viewpoint) of : 从…观点来看

Topic Five: Text learning and keywords

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3. Examples are solar energy, hydropower, wind, geothermal energy, tidal power, and ocean thermal.

hydropower: 水力发出的电力 hydro- : “ 水 , 液 , 流体、氢的 含氢的”之义

hydrodynamics: 流体力学 hydrocarbon: 烃、碳氢化合物

Topic Five: Text learning and keywords

4. It is always desirable to minimize the use of energy derived from nonrenewable resources.

desirable: 值得做的 derived from: 来源于

5. Even though the energy is sometimes free of cost, the cost of equipment to utilize it increases as more energy is used.

6. These principles are largely based on the First and Second Laws of Thermodynamics.(basic principle)

Thermodynamics: 热力学 thermo- ： “热、热电”之义

Thermochemistry: ？？ thermocouple: ？？

free of cost: 免费的

Topic Five: Text learning and keywords

7. An example is the generation of electrical power, as shown in Figure 8.

8. Under the best practical circumstances only about 30 BTU of the 80 BTU delivered to the turbine can be converted into work.

9. It is generally unnecessary and often wasteful to convert heat into power and then back into heat again.

BTU: 英制热量单位 1BTU = 0.252 kcal = 1055.06 JBritish Thermal Unitdeliver: 递送、传送 turbine: 涡轮机

convert…into (to): 将…转化为

排出废热 50BTU 能量散失 20BTU

100BTU能量输入 锅 炉 输出 30BTU

(燃料)

发电机 80BT 汽轮机

Topic Five: Text learning and keywords

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10. An example of this is the generation of electricity at a power plant, as above, and then delivering it to buildings, where through electric resistance heaters, it is converted back to heat.

11. If heat is converted into power, the remainder of the heat that cannot be converted into power should be used for heating or cooling, and not wasted, if practical. This is the basis for total energy system (TES), which generates all of its energy needs (power and heat) at the site and utilizes the maximum part of the energy that is practically available.

power plant: 电厂 electric resistance heaters: 电阻加热器thermal power plant:?? nuclear power plant:???

remainder: 剩余物 utilize: 利用CCHP （ Combined Cooling Heating Power ） System: ?

Topic Five: Text learning and keywords

12. Reduced HVAC energy consumption in building construction usually is a direct result of minimizing heat gains and losses.

13. ASHRAE Standard and some state codes deal with design criteria of HVAC system.

14. A HVAC system designer should try to design the most energy efficient system.

heat gains: 得热量 heat losses: 热量损失

ASHRAE: 美国采暖 , 制冷与空调工程师学会

American Society of Heating Refrigerating and Air conditioning Engineers

energy efficient system: 节能系统

Topic Five: Text learning and keywords

15. The most complete procedure in analyzing energy use in an existing building includes measuring energy consumption of each piece of equipment, flow rates, temperatures, pressures, noting types of systems, controls, and their operations.

16. The results will suggest what conservation steps should be implemented.

17. If the cost of a detailed energy analysis is prohibitive, a “walk-through” survey and recommendations by an experienced energy consultant may suffice, but are not usually as effective.

existing building: 实际存在的建筑物 既有建筑

prohibitive: 禁止的、不可能的 consultant: 顾问

walk-through: 马马虎虎的排练，引申为简单的

suggest: 建议

Topic Five: Text learning and keywords

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18 The more reliable methods include consideration of solar effects, internal gains, heat storage in the walls and interiors and the effects of wind on both the building envelope heat transfer and infiltration.

19 This can be a simple estimate of duct or piping losses or gains, or a complex hour-by-hour simulation of an air system, such as variable air volume with outdoor air cooling.

solar effects: 太阳辐射的影响 internal gains: 室内得热heat storage: 蓄热 interior: 内部结构building envelope: 建筑物围护结构 infiltration: （风）渗透

duct or piping losses or gains: 管路热损失或得热hour-by-hour simulation: 逐时模拟 variable air volume: 变风量VAV system: 变风量系统 Frequency Inverter: ?

Inverter Air Conditioner: ? variable frequency Air Conditioner:?

Topic Five: Text learning and keywords