Manju - Renewable Heat · Dr. Manju . Overview Geoenvironmental Research Centre Canolfan Ymchwil Ddaearymgalcheddol Current State of Monitoring • Site detail • Selection of sensors

T: +44 (0) 2920 874004F: +44 (0) 2920 874004

email: [email protected]: www.grc.cf.ac.uk

Geoenvironmental Research Centre, Cardiff School of Engineering, Cardiff University

Geoenvironmental Research CentreCalnolfan Ymchwil ddaearymgalcheddol

Horizontal Loop - Monitoring Systems

27th September 2012

Dr. Manju

Overview

Geoenvironmental Research CentreCanolfan Ymchwil Ddaearymgalcheddol

Current State of Monitoring

• Site detail• Selection of sensors• On site Sensors Arrangement• Data Acquisition system and Data Management• Site Investigation • So far collected data

Seren Step forward for monitoring- Work in Progress

Potential usage of data

High Profile Projects in Wales


Project Ground Source Heat Pump

Borehole/Ground Loop

Depth of borehole(m)

BREEAM Rating

Energy Centre, Bangor Heating 16 Boreholes

100 Excellent

IBEARS, Aberystwyth University

Heating NA NA Excellent

School Of Optometry and Vision Sciences, Cardiff University

Heating and Cooling

56 Boreholes

100 NA

National Assembly for Wales, Cardiff

Heating and Cooling

27 Boreholes

100 NA

Monitoring GSHP Systems


• Sites• School Of Optometry and Vision Sciences • National Assembly for Wales

• Monitors • Hot and Cold tank temperatures • Inflow and Outflow temperature of the borehole

• Points are just live values, meaning no history on them........

Current State

• To find answer to the question of Sustainability of GSHPs• Long-term behaviour of GSHPs• Significant market penetration: a proof of long-term reliable operation

Why?

Monitoring Parameters – Seren Attempt


• Solar Radiation • Rainfall• Ambient Air Temperature

Climate DataClimate Data

• Soil Temperature Ground Data

• Flow rate• Temperature Differential across the Heat Extractor

Operation Parameters

• 15 mins Recording time

Site Details


Detailed cross‐section

Intermediate cross‐sectionTipping bucket rain gauge

Silicon‐cell pryranometer

ManifoldChamber

HouseFootprint

HeatPump

1 2 3 4 5

Location Lower Pentre Farm located in Ffynnon Gynydd, Powys

Building Type Refurbished old cottage

GSHP system Provides building space heating and hot water need

Horizontal ground Loop 5 Nos. 75 m long trenches

Depth of Trench 1.8 m

Monitored since May 2012

Basis of Sensor Selection


Parameter Reason

Robustness Resist the in-situ ground conditions

Durability and Longevity Duration of monitoring

Operating Range Within the anticipated temperature range

Water Resistance Subject to saturated soil condition

Precision and Accuracy Capable of measuring the temperature to the appropriate data resolution

Data Logging Compatible with the selected data logging equipment

Specification of sensors


Property DetailsMeasurement precision

±0.2º C

Operating temperature -80º C to +75ºC

Stability 0.01 ºC or better per 100 months at 0 ºC

Resistance at 25º C 2252, 3k, 5k, 10k ohms

Cable type Direct burial rated 22 gauge water blocked instrumentation cable

Temperature- Thermistor String Rainfall – Tipping Bucket Rain Gauge Property DetailsAccuracy 2 % up to 25 mm/hr, 3 % up

to 50 mm/hr

Operating temperature -20ºC to +50ºC

Resolution 0.1 mm per tip

Catchment area 200 cm2

Dimensions 18 cm diameter, 39 cm high (including mounting base)

Specification of sensors


Property DetailsThermal conductivity reading accuracy

±2.5 %

Specific heat capacity reading accuracy

±2.5 %

Thermal diffusivity reading accuracy

±5.0 %

Operating Temperature -50ºC to +150ºC

Range of conductivity measurements

0.02 to 4 W/m.K

Range of specific heat capacity measurements

0.5 to 4 MJ/m3K

Probe dimensions 10 cm long, 0.24 cm diameter

Solar Radiation - Pyranometer Thermal Conductivity - KD2 ProbeProperty DetailsAbsolute accuracy ±5 %

Uniformity ± 3 %

Sensitivity Custom calibrated to exactly 5.00 W/m2 per mV

Dimensions 2.40 cm diameter, 2.75 cm high

Mass 70 g (excluding signal wire)

Input power None, self-powered

Materials Anodized aluminium with cast acrylic lens

Layout of Sensors-Intermediate


22.5

m22

.5m

30m

75m

A A

B B

Heat Pump

Ground loop base

Ground loop

10 m

10 m

2.5 m

10 m

10 m

10 m

10 m

10 m2.5 m

The objective of these sensors is to record the temperature of ground layingimmediately adjacent to the ground loop.

Layout of Sensors- Detailed


Topographical Survey

3D view of sensors position3D view of sensors position

Three dimensional position of sensor and sampling points are located using GPS (Global Positioning System).

Data Acquisition System


Weather Station

Plant room

Data-logger unit and modem

Signal WireHouse Footprint

External Wall

Wires leading to horizontal ground loops

Multiplexer

Property DetailsAnalogue inputs 16 single-ended or 8

differentially individually configured

Maximum scan rate 100 Hz

Digital ports 8 I/Os or 4 RS232 COM

Memory 2 MB Flash (operating system) 4 MB (CPU usage, program storage and data storage)

Power requirements 9.6 – 16V, DC

Dimensions 23.9 x 10.2 x 6.1 cm

Data Logger-Campbell Scientific CR 1000

• Enabled the system to be continually monitored

• Enabled logged data to be remotely downloaded off-site.

Data Management Tool


Identify and extract data based on:Time ranges

Temperature ranges

Specific sensors groups

Site Investigation


2.5

m2.5

m

Detailed cross‐section A

Detailed cross‐section B

Intermediate cross‐section A

Intermediate cross‐section B

Intermediate cross‐section C

Intermediate cross‐section D

Intermediate cross‐section E

Intermediate cross‐section F

10

m10

m

10

m10

m

10

m10

m

10

m

1

2

43 5

6

7

98 10

11

12

Tube and PSD samplesTube Sample Locations

Soil Properties determined

Thermal conductivity

Specific heat capacity

Moisture content

Porosity

Bulk unit weight

Particle Size Distribution (PSD)

Mineral content

Soil Characterisation


Soil Properties Min. Max. Avg. Test Type

Thermal Conductivities 2.06 2.87 2.44 In-site

Moisture content 8 15 12 Lab

Bulk Unit Weight 13 19 16 Lab

Mineral Content Quartz Lab

Soil classification Lab

Sample 1: Fine Grained soil (Inorganic silt, ML) >70% passing 75 m

Sample 2: Coarse Grained soil (Gravel) <36% passing 4.5 mm

Data Collection- Undisturbed Ground Temperature


90.469, 16.53

90.469, 15.56

90.469, 14.12

8

10

12

14

16

18

20

0.000 10.000 20.000 30.000 40.000 50.000 60.000 70.000 80.000 90.000 100.000

Tempe

rature(C°)

Time(Day)

Temperature with time

0.569

1.304

2.576

0

200

400

600

800

1000

1200

1400

5/11/2012 5/31/2012 6/20/2012 7/10/2012 7/30/2012 8/19/2012 9/8/2012

Sol

ar R

adia

tion

(W/m

2 )

Time (Days)

Solar Radiation

0

2

4

6

8

10

12

14

16

18

20

13 23 33 43 53 63 73 83 93 103

Ra

infa

ll (

mm

)

Time (days)

Daily Rainfall

Data Collection –Heat Extraction Process


0

100

200

300

400

500

600

12

12.5

13

13.5

14

14.5

15

15.5

9/7/2012 9/9/2012 9/11/2012 9/13/2012 9/15/2012 9/17/2012 9/19/2012 9/21/2012 9/23/2012

Cu

mm

ula

tive

Flo

w (

Lt)

Te

mp

era

ture

(c

0)

Time (days)

Ground Temp

Cummulative 15 min Flow

Potential usage of data


Good case study

Unique set of data, since many relevant parameters will be digitally recorded over several years

Measured temperature will be used to calibrate the numerical model

Calibrated model can in turn be used to forecast the future behaviour of the GSHP system.


Thank You!

Documents

Manju - Renewable Heat · Dr. Manju . Overview Geoenvironmental Research Centre Canolfan Ymchwil Ddaearymgalcheddol Current State of Monitoring • Site detail • Selection of sensors