Yutaro ShimadaNov. 23rd, 2018, “DMR special talk”, Bangkok, Thailand

Department of

Transdisciplinary Science and

Technology

Result of Experiment for “Optimal

Operation of GSHPs in Thailand”

under the “CCOP-GSJ/AIST

Groundwater Project”

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Introducing myself about background and research fields

・BackgroundThe department of

“Mechanical Engineering”

・PresentThe department of

“Global Engineering for Development, Environment and Society”

New Technology

Society

Our research field : Assessment the potential and benefit of new technology for society

Efficiency

Economy

Environment

Series o

f Assessm

ent

Final year project :Life cycle assessment of GSHP in Thailand

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1. What is “CCOP – GSHP” Project ?

2. Review of Experiment

3. Result of Operation (Subsurface Temperature)

4. Result of Operation (Analysis of Heat Pump Working)

5. Suggestion of Optimal Operation and its Result

6. Problem

7. Future Plans

Contents of Presentation

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1. What is “CCOP-GSHP” project ?

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What is Heat Pump ?

Schematic of Heat Pump System Working

Heat Pump : Device for transferring heat energy from colder place

to warmer place

ex) Refrigerator, Air Conditioner, Hot water supply etc.......

Freon Gas Circulation

Fan Coil Unit

Cool Heat to Room

Overview of Heat Pump System Working

Warm Heat to Heat Source

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What is GSHPs ?

(Ground Source Heat Pump system)

Difference of normal air conditioner and GSHPs

Normal Air Conditioner

(ASHP: Air Source Heat Pump)GSHP: Ground Source Heat Pump

Main difference : where the heat is released to (Heat Source)ASHP = Atmosphere (30~35℃), GSHP = Ground (28~30℃)

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What is GSHPs ?

Types of GSHP system

Open Loop System(Groundwater usage type)

Aquifer Aquifer

Heat Pump Heat Pump

Polyethylene U-tube

Heat Intake

Intake Well

Recharge Well

Closed Loop System(Borehole heat exchanger type)

50～100m

・Most High Efficiency・Ground Water Environment・Maintenance Cost

・Maintenance Free・Still High Efficiency ・Difficulty of Designing

Open Loop System Closed Loop System

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What is GSHPs ?

(Ground Source Heat Pump system)

Advantage of GSHPs

➢ Save energy and reduce CO2

gas emission

➢ Mitigate Urban Heat Island Phenomenon

➢ Normalize electricity consumption through a day

Disadvantage and Weakness of GSHPs

➢ Large Initial Cost ➢ Low Awareness

➢ Difficulty of Designing

Yasukawa et al (2009)

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GSHPs in Tropical Regions

GSHPs is suitable to Tropical Regions ?

Not really in tropics…

Monthly mean atmospheric and subsurface temperature

However...

If there is rich “groundwater

flow”, underground

temperature would be

decreased.

CCOP – GSJ/AIST Project

Survey of Groundwateris important

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CCOP-GSJ/AIST Project

CCOP-GSJ/AIST Groundwater

Project Phase II (2009 ~ 2013)

➢Main theme in this project is “Renewal of

database for the Hydro-geological map in

CCOP regions”

➢To construct database and its design

➢To compile data of Chao-Phraya Plain,

Thailand and Red River Delta, Vietnam

➢To make an Asian Standard of the Hydro-

geological map

CCOP GW-Database

Involvement of GSJ in the project➢ Phase I (2005 ~ 2008)➢ Phase II (2009 ~ 2013)➢ Phase III (ongoing)

Field Survey Hydro-geological map of Chao-Phraya Plain

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The Data from “CCOP/GSJ-AIST PhaseⅡ”

Comparison between subsurface and atmospheric

temperature

Subsurface temp (0-50m)

Atmospheric monthly mean max.

Atmospheric monthly mean min.

Atmospheric annual mean

Ref: Yasukawa et al., 2009

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CCOP Groundwater Sub-Project “Development of Renewable Energy for Ground-Source Heat Pump System in CCOP Regions”

• New sub-project under CCOP GW Project usingCCOP GW DB started from April 2013

• Title of the sub-project is “Development ofRenewable Energy for Ground-Source HeatPump System in CCOP Regions”

• Chulalongkorn University (Thailand), AkitaUniversity (Japan) and GSJ have cooperationprogram under the CCOP sub-project andinstalled GSHP System on premise ofChulalongkorn University

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Objectives of this sub-project are;

➢ To demonstrate GSHP system in Bangkok City, Thailand

➢ To find out adjustment and modifications needed forGSHP system in tropical region

➢ To develop suitable maps for GSHP system in Thailandreflecting large-scale groundwater flow/heat transportmodel

Continued

This is my main research target

+ Environmental Evaluation and Economic Evaluation

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GSHP Facility in Thailand (2018)

Chulalongkorn University

(Department of Geology)

Golden Jubilee National Geological

Museum, DMR (Pathumthani)

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Short Break : Status of Energy Policy and Use in Thailand

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Source:Y. Yungchareon & B. Limmeechokchai(2004)

・ Target of GHG (Green House

Gas) emissions reduction by 2030 in Thailand's ParisAgreement：Reduce by 20～25%

・ 70% of GHG emissions in Thailand: energy consumption.

・ 40% of energy consumption: energy industry ex) power generation

(Electricity Supply)

・ 60% of electricity consumption: air conditioning

Improvement of efficiency of air-conditioning system have a important role for Thailand’s energy saving and environment

Status of energy policy and use in Thailand

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2. Review of experiment

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Experiment stage to Demonstration stage

・For the future development of GSHP

Experimental at Chulalongkorn Univ ×100～

×2～3

Important things

1. Controlling Subsurface Temp

2. Life Cycle CO2 (Environment)

3. Life Cycle Cost (Economic)

*Life Cycle: Construction~Use~Disposal

Geological Museum DMR(Pathumthani)

Background of Experiment

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Background of Experiment

Subsurface Temperature Increasing

Approaching to solve the problem

Temperature around heat exchanger

would be getting increased after

GSHP operation.

Negative Influence on...・Efficiency ・Underground environment・Sustainability

1. Optimal operation (Morning? Afternoon? Evening? 24 hours?)

2. GSHPs combined with ASHPs

3. Generate Hot Water Supply by GSHPs

Target for experiment at Chula univ

Evaluation by simulation

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Setting for Optimal operation

a) Criterion of optimal operation

b) Settings for GSHP (+ASHP) operation

1. Recover the subsurface temperature by 1 day or 1 week

basis

2. Minimum Electricity consumption

“ 1 + 2 = Optimal Operation “

・Condition 1 : GSHPs covers 12:00～15:00, ASHP cover the other time.

・Condition 3 : Only GSHPs covers all operation time

GSHPASHP GSHP

Condition 1 Condition 2

・Condition 2 : ASHPs covers 12:00～15:00, GSHP cover all time.

GSHPASHP+GSHP

Condition 3

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3. Result of Operation (Subsurface Temperature)

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・Condition 1 (Retail Store, Education and Office)

9:00～12:00 : ASHP12:00～15:00 : GSHP15:00～22:00 : ASHP

8:00～12:00 : ASHP12:00～15:00 : GSHP15:00～16:30 : ASHP

Retail Store

Education and Office

Subsurface Temp : Not Increased

3.92～5.84 kWhAve. 4.76 kWh

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0.2℃

・Condition 2 (Education and Office)

Education and Office

8:00～12:00 : GSHP12:00～15:00 :GSHP+ASHP15:00～16:00 : GSHP

Subsurface Temp : Increased slightly

＊Depending on Weather Condition

1.84～2.88 kWhAve. 2.39 kWh

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・Condition 2 (Retail store) Retail Store

Retail Store

9:00～12:00 : GSHP12:00～15:00 :GSHP+ASHP15:00～22:00 : GSHP

0.15℃

0.92℃Subsurface Temp

: Increased significantly

＊2 days to recover

2.36～4.62 kWhAve. 3.47 kWh

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・Condition 3 (Education and Office)

Education and Office

8:00～16:00 : GSHP

0.5℃

1.2℃

Education and Office

Subsurface Temp : Increased

significantly

＊3～4 days to recover

1.52～2.8 kWhAve. 2.3 kWh

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・24 hours operation

24 hours : GSHP

1.8℃

Subsurface Temp : Increased

significantly

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4. Result of Operation(Analysis of Heat Pump Working)

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・Relation Between “COP” and “Cooling Load”

GSHPsASHPs (Rough Calculation)

Common : “Low cooling load, Low COP” and “High cooling load, High COP”(*Its relation is not linear, but curve )

Difference : COP of GSHP is better than that of ASHP (GSHP : High efficiency)

ex) COP of GSHP = 3.5, COP of ASHP = 2.5

28.6 % Savings of Electricity consumption

＊ASHP’s COP Calculation …I defined the cooling load is equal, if the atmospheric temperature curve are similar to each other

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・Transition of Cooling Load in 1 day

・・・・・・

Transition of Cooling Load

・1 hour after starting operation on morning

・12:00~16:00

・Until noon from 1 hour after starting operation on morning

・17:00~Next morning

Large Cooling Load

Small Cooling Load

Model of daily Cooling Load

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5. Suggestion of Optimal Operation and its Result

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・Suggestion of optimal Operation

・Short Summary of Result

1. Subsurface Temperaturea. 3 hours operation on afternoon does not affect subsurface temperature.b. 8 hours operation (+ ASHPs on afternoon ) will affect subsurface temp

depending on weather condition.

2. Efficiency a. GSHP is better than ASHP. b. Both efficiency are going to be decline with small cooling load.

3. Cooling Load1 hour after start operating : large, Until Noon : small, Until 16:00: largeUntil next morning : small

Suggestion of Optimal Operation

9:00～10:00 : GSHP, 10:00～12:00 : ASHP, 12:00～16:00 : GSHP, 16:00～22:00 : ASHP

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・Result of Optimal Operation

Optimal Operation

Optimal Operation

0.5℃-0.15℃

9:00～10:00 : GSHP10:00～12:00 : ASHP12:00～16:00 : GSHP16:00～22:00 : ASHP

Subsurface Temp : Increased slightly

＊Depending on Weather Condition

＊2 days to recover

5.02～6.09 kWhAve. 5.43 kWh

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6. Problem

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Problems

a) Accuracy of Subsurface Temperature Data

1. Thermistor sensor is set too

close to heat exchange well

Chokchai et al (2018)

・Setting a temperature sensor apart at least 5 m from heat exchange well

2. Thermistor sensor is affected

by groundwater or precipitation

・To improve the sensor accuracy, replace thermistor to thermocouplesensor

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Problems

b) The Long Term Experiment (at least 1year basis)

To know the trend and limit of underground heat exchange ratio ...

・At least operating GSHP one or two year continuously (3 months is not enough)

Experiment Simulation

Experiment

Cir

cula

tio

n W

ater

Tem

p

Simulation

Time

“1 year experiment result”

and “simulation of 10 years

operation from experiment”

(In case of Tokyo)

1 year 10 year

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7. Future Plans

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Three kinds of thermal conductivityThermal conductivity is one of the inherent properties of the materials to conduct heat. It is used to characterize quantity of stable heat transfer.

Lower

Higher

Thermal conductivity

Thermal conductivity is the thermal properties of a material

to conduct heat in unsaturated state of ground, meaning the

unique value of the material.

Effective Thermal conductivity

Effective thermal conductivity is the thermal properties in

saturated state of ground.

Apparent thermal conductivity

Apparent thermal conductivity involves effect of thermal

advection due to groundwater flow. The faster groundwater

flow rate enhances thermal conductivity.

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・History matching with TRT (Thermal Response Test)

What is TRT (Thermal Response Test) ?

One of the method for predicting the thermal conductivity of the subsurface in situ

Circulation WaterTemperature Increasing

1. Forced heating subsurface with a heater (more than 48 hours)

2. Record the circulation water temp increasing

3. Calculate the thermal conductivity from temp increasing curve

Specific Methodology

Schematic figure of TRT

TRT : Important for predicting GSHP efficiency

Circulation WaterTemperature Increasing Curve

Gradient →Thermal Conductivity

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Ex) Simulation of operation about 25th Sep from the specificationdecided by TRT test simulation

・History matching with experimental data more and more・Using another software...?

TRT test at Chula univ (13th～16th Feb)

・History matching with TRT (Thermal Response Test)

What is “History matching” ?

Method for matching simulation result with analytic solution

1. Analytic simulation with using parameter decided by TRT

2. Comparing the simulation result by TRT result with temp increasing curve

Specific Methodology

Confirmation and Check

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・Future Research Plan

After confirming the parameter of subsurface specification......

1. Target Facility2. Cooling Load3. Combined Heat Pump with various

heat source

1. Schedule of Operation

2. Designing Ground Heat Exchanger

*Based on simulation

Designing air conditioning system

Operation Designing

Energy ConsumptionLife Cycle CO2

emission

Economic Point (Cost)

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Last : Kind Request to DMR stufffrom our Team ☺

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We will be very appreciate if you are prefer

to join “CCOP-GSHP Project” for further developing of GSHP at Tropical regions

If possible....

For Example...

➢ Conducting a long term experiment

➢ Analysis of subsurface condition from Geological point of view

➢ Development of suitability map of GSHP system based on Geological Information in Thailand

etc...

Thank You