Research on the Clean Energy Heating Systems in Rural Beijing

Available online at www.sciencedirect.com

ScienceDirect Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2017) 000–000

ScienceDirect ScienceDirect

www.elsevier.com/locate/procedia

Energy (2017) 000–000 137–143 EnergyProcedia Procedia143 00 (2017) www.elsevier.com/locate/procedia

World Engineers Summit – Applied Energy Symposium & Forum: Low Carbon Cities & Urban Energy Joint Conference, WES-CUE 2017, 19–21 July 2017, Singapore

Research The on 15th the International Clean Energy Heating Systems Symposium on District Heating in andRural CoolingBeijing a,b feasibility ofa using the heat Assessing the Qunli Zhang *,Yangyang Hao ,Donghan Suna,Qiandemand-outdoor Niea,Liwen Jinc temperature forVentilating a long-term district heat Beijing Municipal Key Lab offunction Heating, Gas Supply, and Air Conditioning Engineering. Beijing demand University of Civilforecast Engineering and

a

Architecture, Beijing 100044, China; a,b,c a b Engineering and Architecture.Xicheng c c Bejing Advanced Innovation Center for FutureaUrban Design.Beijing University of Civil District,Beijing 100044, China; c Group a of Building Environment and Sustainability Technology, Building Environment and Equipment Engineering, Xi’an Jiaotong University, IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal Xi’an and 710049,China. b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France b

I. Andrić

*, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Corre

Abstract Abstract Fog and haze weather has seriously affected many important aspects of human life and physical fitness. In order to improve air quality, local government has transformed coal-fired heating into clean energy heating in Beijing rural areas. This paper District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the introduces three typical clean energy heating systems which are low temperature air source heat pump (LTASHP), thermal greenhouse emissions from the building sector.(WGF), These systems require high the investments which are situation returned of through the heat storage heatergas (TSH) and wall-mounted gas furnace researches and tests practical operation three heating sales. Due to field. the changed climate conditions and building renovation policies, heat demandtheinpaper the future couldresidence decrease, systems in the To compare technical and economic feasibility of three heating systems, takes such prolonging the investment return where energy-saving standard of period. building palisade structure is approximately 50% as the research object, and establishes The mainand scope of this paper is to assess the feasibility of using the heat demand outdoor temperature function foremissions heat demand technical economic mathematical analysis models, compares primary energy –consumption and carbon dioxide of forecast. Thesystems. district This of Alvalade, located in Lisbon (Portugal), was used as atakes case into study. The district is consisted of 665 three heating paper adopts annual cost approach, comprehensively account power capacity increasing buildings thatpipe varynetwork in both construction construction fee, period typology. Three weather scenarios medium, threeheating district tariff and gas andand compares initial investment, operation (low, cost and annualhigh) cost and of three renovation scenariosfrom werethedeveloped (shallow, deep). estimate obtained values were systems respectively perspective of usersintermediate, and government. TheTo results showthe thaterror, LTASHP is theheat mostdemand energy-saving and its annual cost lowestfrom in the three heating systems.model, LTASHP is the most suitable alternative to coal-fired heating in compared withisresults a dynamic heat demand previously developed and validated solutions by the authors. the three heating systems ruralonly Beijing. The results showed that in when weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation ©scenarios, 2017 Thethe Authors. Published by Elsevier Ltd. (depending on the weather and renovation scenarios combination considered). error value increased up to 59.5% Peer-review under responsibility the scientific committee of the Summit Applied Energy The value of slope coefficient of increased on average within the World range Engineers of 3.8% up to 8%–per decade, that Symposium corresponds&to the Forum: Low Citiesof&heating Urban hours EnergyofJoint Conference. decrease in Carbon the number 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the Keywords: clean energy;The heating system; LTASHP; technical and economic analysis; annual cost approach; for the scenarios considered, and coupled scenarios). values suggested could be used to modify the function parameters improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. * Corresponding author. Tel.:+86-13522898182; E-mail address: [email protected] Keywords: Heat demand; Forecast; Climate change

1876-6102 © 2017 The Authors. Published by Elsevier Ltd.

Peer-review under responsibility of the scientific committee of the World Engineers Summit – Applied Energy Symposium & Forum: Low Carbon Cities & Urban Energy Joint Conference.

1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the World Engineers Summit – Applied Energy Symposium & Forum: Low Carbon Cities & Urban Energy Joint Conference. 10.1016/j.egypro.2017.12.661

Qunli Zhang et al. / Energy Procedia 143 (2017) 137–143 Qunli Zhang/ Energy Procedia 00 (2017) 000–000

138 2

1. Introduction Beijing has established various kinds of policies and measures to clean air, and carried out the regulation of air pollution. The sources of PM2.5 mainly include automobile exhaust, coal-fired power plants, industrial coal boiler, town coal heating boilers, rural coal heating, rural biomass heating and industrial production process (BMBEP,2014). Rural coal consumption is about 4 million tons of standard coal every year, among them 92% coal is used for winter heating (Yongjie Zhang, Jianyun Jiang,et al. 2014). These papers (Ming Shan, Ming Yang,et al.2011, Ming Shan, Pengsu Wang,et al.2012) aimed at the problems which refer to the rapid growth of the rural residential coal consumption, low energy efficiency and serious pollution emissions, put forward the construction of “no coal village” development mode in north China. At present, clean energy heating systems transformation is under way in rural areas and urban-rural fringe of Beijing, the main measures are “coal to electricity”, “coal to gas” and high quality coal substitution. It’s remarkable to reduce pollution emissions through these measures, there is no local emission with LTASHP and TSH heating systems, also reduction ratio is 100% (Jianyun Jiang, Yongjie Zhang,et al.2014 ). Using high quality shape-coal, the pollution PM2.5 emission reduces about 55% (Jiandong Ye, Yongjie Zhang,et al.2016 ). When scattered coal heating is transformed into clean energy heating system, users mainly consider initial investment, operating cost, indoor comfort, while government focuses on comprehensive annual cost including infrastructure investment. This paper introduces clean energy heating systems in Beijing rural areas, tests running effect on the spot. Assume that energy consumption is nearly equal between the rural residence and the building of envelop enclosure energy-saving standard close to 50%. The paper takes this building as the research object, adopts annual cost approach, compares the technical and economic feasibility of the clean energy heating systems. 2. Research and test in the field In order to get a more accurate and effective data including initial investment and operation cost of clean energy heating systems, this paper has carried on the on-the-spot investigation aiming at LTASHP, TSH and WGF heating systems, as shown in Table 1. 2.1. General situation of research and test sites (1) House A is located in Changping district, heating system is LTASHP, the end of heating system is radiator. The total electricity consumption of heating season is about 4282 kWh, and indoor temperature stays around 17~18℃. (2) House B is located in Miyun district, heating system is unitary air source heat pump, the end of heating system is low temperature radiant floor. The house is single-family small high-rise residential building, where the energy-saving standard of building palisade structure is 65% The total electricity consumption of heating season is about 3052 kWh, and indoor temperature stays around 19~20℃. (3) House C is located in Shijingshan district, heating system is three TSHs whose capacity are 3.2 kW、3.2 kW and 1.6 kW, respectively. The total electricity consumption of heating season is about 11667 kWh, and indoor temperature stays around 18~20℃. (4) House D is located in Shijingshan district, heating system is three TSHs whose capacity are 3.2 kW、3.2 kW and 1.6 kW, respectively. The total electricity consumption of heating season is about 13333 kWh, and indoor temperature stays around 17~19℃. (5)House E is located in Daxing district, heating system is WGF, the end of heating system is low temperature radiant floor. The total gas consumption of heating season is about 1391 m3, and indoor temperature stays around 18~19℃. (6)House F is located in Chaoyang district, heating system is WGF, the end of heating system is radiator. The total gas consumption of heating season is about 614 m3, and indoor temperature stays around 18~20℃. Table 1 Measured heating costs of different heating systems



Qunli Zhang et al. / Energy Procedia 143 (2017) 137–143 Qunli Zhang/ Energy Procedia 00 (2017) 000–000

Test sites

Heating systems

Heating area （m2）

Initial investment （Yuan）

House A

LTASHP+ radiator

96.8

House B

LTASHP+ floor heating

House C House D

Heating fee

Initial investment

139 3

Operation cost

（Yuan）

（Yuan /m2）

（Yuan /m2）

24000

2091

248

21.6

90

22000

1490

244

16.6

TSH

60

6600

3500

110

58.3

TSH

80

6600

4000

82.5

50.0

House E

WGF + floor heating

118

17700

3172

150

26.9

House F

WGF+ radiator

48

7400

1400

154.2

29.2

2.2. Comparison and analysis of the measured value From the view of initial investment, LTASHP is highest, WGF is second, TSH is lowest. The government and the districts subsidies of various equipment’ initial investment are different. Basic subsidy of the LTASHP system is 240 Yuan per square meter. The subsidy of the TSH and WGF is two thirds of the total amount of investment. After the subsidy, the initial investment of the WGF is highest, while the LTASHP is lowest. From the view of operation cost, TSH is highest, WGF is second, LTASHP is lowest. From the point of indoor comfort, using LTASHP or WGF the stability of room temperature is better, while the heat comfort of TSH is general. Using low temperature radiant floor as the end of the heating system, indoor comfort is better. 3. Energy saving analysis of different heating systems 3.1. Typical working condition set In order to analyze the energy saving and economy of the three heating systems, assume that heating area is 100 square meters, heating time is 120 days, building designed heating load is 32.0 W/m2, building average heating load is 20.5 W/m2, building heat consumption is 59.60 KWh/m2, the outdoor calculated temperature of heating in winter is -9℃, and indoor heating design temperature is 18℃. 3.2. Energy saving analysis mathematical model The primary energy consumption calculation models of different heating ways are presented in the following formulas. The energy consumption model of LTASHP heating system is formula (1).

Q 

Qh COPzheenet

(1)

The energy consumption modle of TSH heating system is formula (2).

Q 

Qh heenet

(2)

The energy consumption modle of WGF heating system is formula (3).

Qh 

Qh gb

(3)

In these formulas, Qh is heat consumption of built-up area in heating season, and unit is KWh/m2. COPzh is coefficient of heating season heating performance, and select 3. ηe is national average power generation efficiency,and select 35%. ηenet is power grid transmission efficiency , and select 92%. ηh is electrothermal

Qunli Zhang/ Energy (2017) 143 000–000 Qunli Zhang et al.Procedia / Energy 00 Procedia (2017) 137–143

4 140

conversion efficiency, and select 99%. ηenet is WGF heating efficiency, and select 90%. 3.3. Results of energy saving analysis (1)Energy consumption per unit area Primary energy consumption of the three heating ways converts into amount of standard coal, as shown in Fig.1. The primary energy consumption of TSH heating system is 22.9 kgce/m2,which is highest in the three clean energy heating systems. The primary energy consumption of WGF heating system is 8.1 kgce/m2. The primary energy consumption of LTASHP heating system is 7.6 kgce/m2, which is lowest in the three. So LTASHP heating system is the most energy-efficient in the three heating systems.

Fig.1.Primary energy consumption of different heating systems

Fig.2.Carbon dioxide emissions of different heating systems

(2) Carbon dioxide emissions per unit area By calculating the CO2 emissions with different energy sources, the local or global carbon emissions generated by three heating systems are shown in Fig.2. CO2 emission of TSH is three times as much as that of LTASHP, so LTASHP is more clean heating system than TSH. 4. Economic analysis of different heating systems 4.1. Annual cost approach Economic analysis more commonly adopts annual cost approach and additional investment repayment life method, this paper adopts annual cost approach(ZhiJiang Zhang, Jin Tao,et al.2004). Heating efficiency index includes initial investment, operation cost and annual cost. The initial investments of heating systems are the cost of equipment and materials, infrastructure construction cost and power capacity increasing tariff, etc. The operation costs are fuel cost, depreciation cost and maintenance cost, etc. The annual cost is the sum of the reduced initial investment according to the investment effect coefficient and the annual operation cost. The calculation formula of annual cost Z is as follows:

z 

n

 x j kj j

C

(4)

i(1  i )m (1  i)m  1

(5)

1

xj 

In these formulas, n is heating equipment species number. kj is the investment amount of heating equipment j, and unit is Yuan. C is the annual operation cost of heating system, and unit is Yuan/(m2·a). xj is the investment effect coefficient of heating equipment j, and unit is a-1. i is the department internal standard yield; m is the service life of heating equipment. 4.2. Initial investment of different heating systems The investment estimation of LTASHP, TSH and WGF is determined by research. The indoor heating pipe



Qunli Zhang et al. / Energy Procedia 143 (2017) 137–143 Qunli Zhang/ Energy Procedia 00 (2017) 000–000

141 5

network investment estimation index is chosen with reference to municipal engineering investment estimation index (Municipal engineering investment estimation index,2007). When making clean energy heating transformation, the user considers only initial investment of clean energy heating system, initial investment of different heating systems is shown in Fig.3. Government also needs to consider power capacity increasing tariff and gas pipe network construction fee, initial investment of different heating systems is shown in Fig.4.

Fig.3.User’s initial investment of different heating systems

Fig.4.Government’s initial investment of different heating systems

4.3. Operation cost of different heating systems The annual operation costs include fuel cost, depreciation cost and maintenance cost. Annual operation cost of different heating systems is shown in Fig.5. TSHs enjoy low price 0.3 Yuan/kWh, and the time of low price is from 21:00 to 6:00 the next day. The normal electricity price is 0.4883 Yuan/kWh. The gas price is 2.28 Yuan/m3. The maintenance cost calculation is one percent of initial investment of the heating system.

Fig.5.Annual operation cost of different heating systems

4.4. Annual cost of different heating systems The service life of heating equipment is as follows: LTASHP selects 8 years, TSH selects 5 years, WGF selects 8 years and indoor pipeline selects 15 years. The service life of power capacity expansion facilities and gas pipe network selects 15 years. The heating system standard yield selects 3%, which is the bank annual interest rate. The supporting facilities standard yield selects 10%, which is investment annual interest rate. Based on the user's perspective, annual cost is the sum of reduced initial investment of heating system and annual operation cost, as shown in Fig.6. Based on the government's point, annual cost is the sum of reduced initial investment of heating system including capacity-supplementing fee and annual operation cost, as shown in Fig.7.

Qunli Zhang et al. / Energy Procedia 143 (2017) 137–143 Qunli Zhang/ Energy Procedia 00 (2017) 000–000

142 6

Fig.6. Annual cost of different heating systems

Fig.7. Comprehensive annual cost of different heating systems

The above figures show us, first, reduced initial investments of TSH and LTASHP are higher than that of WGF heating system, but the government subsidies of TSH and LTASHP are higher than that of WGF. Considering power capacity increasing tariff and gas pipe network construction fee, the reduced initial costs of LTASHP is the lowest. So if clean energy heating is converted into LTASHP heating system, the government's fund pressure will decrease. Second, the annual operation cost of LTASHP is the lowest in the three heating systems, WGF’s is second, TSH’s is the highest of the three heating systems. TSH enjoys low electricity price policy. If the LTASHP enjoys low electricity price policy, the operation cost is lower. Third, only considering the heating system, the annual cost of TSH is the highest in the three heating systems, WGF is the lowest of the three. Taking into account the power capacity increasing tariff and gas pipe network construction fee, the annual cost of TSH is still the highest of the three heating systems, the LTASHP’s is the lowest of the three. Considering the above factors, when the government conducts clean energy heating modification, LTASHP heating system is the most suitable from the perspective of investment. 5. Conclusions From the aspects of primary energy consumption, initial investment, operation cost and annual cost, this paper comprehensively evaluates the three clean energy heating systems and gets the following conclusions: First, contrasting the three clean energy heating systems, LTASHP heating system is the most energy-efficient. Whether considering power capacity increasing tariff or not, the annual cost of LTASHP heating system is lower than that of TSH heating system. Conducting“coal to electricity”project in Beijing rural areas, it is more suitable to transform into LTASHP heating system than TSH heating system. If conducting LTASHP transformation on a large scale, it can effectively achieve power grid peak shaving. Second, the energy consumption of TSH is the largest of the three clean energy heating systems, and annual cost of TSH is the highest of the three heating systems. The operation cost of TSH is higher, at the same time TSH uses off-peak electricity, which can realize peak load shaving. The TSH is easy to install, and transforming into TSH is the most simple way in “coal to electricity” project. Third, without considering gas pipe network construction fee, annual cost of WGF is the lowest of the three heating systems. After considering the gas pipe network construction fee, annual cost of WGF is higher than that of LTASHP. This kind of heating system needs gas pipe network planning and construction in rural areas. After completing construction, it is also a kind of important clean energy heating system. Acknowledgements The authors acknowledge the supported from project “Study on Synergistic Strengthening Mechanism of Heat and Mass Transfer and Purification in the Process of Spray Flue Gas Condensation Heat Recovery” (Project No. SQKZ201510016001) which is found by Beijing Natural Science Foundation.



Qunli Zhang et al. / Energy Procedia 143 (2017) 137–143 Qunli Zhang/ Energy Procedia 00 (2017) 000–000

143 7

References [1] Beijing Municipal Bureau of Environmental Protection(BMBEP). The Beijing PM 2.5 source resolution was officially released [EB/OL].http://www.bjepb.gov.cn/bjhrb/xxgk/jgzn/jgsz/jjgjgszjzz/xcjyc/xwfb/607219/index.html，2014.4.16. [2] Yongjie Zhang, Jianyun Jiang, and Jiandong Ye. (2014) “The analysis of Beijing-Tianjin-Hebei rural life energy consumption and the suggestions of reducing and replacing coal.” China Energy 36.7 (2014): 39-43. [3] Ming Shan, Ming Yang, and Pengsu Wang. (2011) “The demonstration of building energy-saving village class in north China.” Construction Technology 3 (2011):50-52. [4] Ming Shan, Pengsu Wang, Xudong Yang, and Ming Yang. (2012) “Discussion on the sustainable development model of residential energy consumption in China rural areas.” Construction Technology 9. (2012): 20-25. [5] Jianyun Jiang, Yongjie Zhang, and Rongjiang Ma. (2016) “Effectiveness comparison and analysis of alternative solutions to coal-fired heating in rural Beijing.” HVAC ,46.9 (2014): 51-55. [6] Jiandong Ye, Yongjie Zhang, and Jianyun Jiang. (2016) “Comparison and analysis about mould coal and raw coal for rural heating.” Building energy saving 44.10 (2016): 102-103. [7] ZhiJiang Zhang, Jin Tao, and JiuSheng Shi. (2004)“Technical and economic comparison of some heaing systems with different energy sources”.HVAC, 34.1 (2004): 8-10. [8] The ministry of construction standard quota research institute.(2007) Municipal engineering investment estimation index, the eighth book, the central heating heat network engineering. Beijing: China Plan Publishing House.2007.