eng1002 design project client brief - version 2 · eng1002 design project – s2 2017 – v2 1...

ENG1002 Design Project – S2 2017 – V2 1

Client Brief - Version 2 (additional to V1.11)

1. Project Outline ‘Self Sufficient Lodge’ is an eco-friendly country lodge located on the Great Dividing Range just

north of the city of Toowoomba, where the owners Jura and Ima Green host immersion programs

designed to teach their guests the principles of living a ‘low–impact’ lifestyle. The next stage in the

development of the lodge is the addition of a greenhouse, where guests can learn how to grow their

own food using hydroponics. A diagram an outline of the design and location of the greenhouse is

shown in Figure 1.

Figure 1. Outline of proposed greenhouse

1.1. The Proposed Greenhouse System

The objective is to provide the maximum possible grow table area within a greenhouse environment

in the most cost effective way. This is to be achieved by constructing one semi-circular greenhouse,

in which plants will be grown on specially designed tables into which nutrient rich water is pumped

periodically. The greenhouse is intended to provide protection from insects and other pests and

provide a more stable range of temperature for improved plant growth.

It is proposed that the greenhouse system be comprised of the following equipment:

• One semi-circular greenhouse covered with a semi-transparent plastic film/sheet

• Grow tables which are topped with flood & drain growing trays

• A storage tank, pump and pipe system to circulate (and recover) nutrient to/from each grow

table (pipes not shown in Figure)

• Filter, pump control and ancillary fittings (not part of this assessment)

Students please note – You MUST READ the IMPORTANT NOTES on the last page of this

document. Any comments in the brief in italics are directed at the student for clarification.

end elevation

R radius

L

plan view

2R walk ways

grow tables site plan (available area)

Note: not to scale B = 10 m

60°

A = 15 m tank

any arrangement

min spacing

s=0.8 m

around all

equipment

any orientation

h=0.75 m

table height

s=0.8 m

door width s=0.8 m

D

pump 1 m x 1 m

various layouts

greenhouse

must be in

this corner


2. Project Design Sections The project will be divided into five design sections including a costing, to ensure that the

requirements of the project are clear. Each section of the design is defined by the set of design

parameters, listed in bold. Any company submitting a design proposal must use the stated variable

letters for these parameters. Each design section requires a technical analysis which must be

summarised in the final design proposal. The section numbers are:

1. Dimensions of the greenhouse, number and layout of the grow tables

2. Storage tank

3. Pump and piping

4. Greenhouse sheeting and temperature control

5. Project costing

2.1. Section 1 – Greenhouse and Grow Tables The greenhouse is a long semi-circular structure comprised of a metal frame covered with translucent

plastic sheeting. The translucent sheeting keeps most pests out, allows lots of sunlight and heat energy

in during the day and helps retain some of that heat energy during the night. One corner of the

greenhouse must be positioned in the lower right corner of the available area as shown in Figure 1.

One door 0.8 m wide x 2.0 m high (also covered in plastic sheeting) is in each end of the greenhouse.

Each door can be positioned as required. Some sections of the plastic sheeting are able to be opened

to control temperature, but this does NOT affect the dimensions of the greenhouse. The cost of the

greenhouse is proportional to its surface area and dependent on which material is specified.

The layout of the grow tables and walkways in the greenhouse is flexible, but it expected that tables

will be arranged in rows with walkways between them and that each walkway connects to a door at

each end. Each walkway is 0.8 m wide and the maximum reach for a person tending the plants is not

to exceed 0.8 m from the edge of a walkway.

The grow tables come in two sizes – Small 0.8 m x 1.6 m and Large 1.6 m x 1.6 m.

The greenhouse and grow table configuration is defined by its layout and the parameters:

• R – the radius (m) of the greenhouse

• L – the length (m) of the greenhouse

• NS – the number of small grow tables

• NL – the number of large grow tables

• AG – the grow table area (m2)

• AS – the surface area of the greenhouse (m2)

The technical analysis of this section should determine:

• At least two layouts which meet the requirements

• The relationship between the radius (R) and the number of rows for grow tables

• The relationship between the length (L) and the number of grow tables (NS NL)

• The equation for the grow table area (AG)

• The equation for the surface area (AS) of the greenhouse


Relevant Constraints

• The maximum radius for the greenhouse is 6 m, for this type of construction

• The minimum head height above walkways inside the greenhouse is to be 2.1 m

• The maximum reach by a person tending the plants is 0.8 m from the edge of a walkway

• A minimum spacing of 0.8 m is to be provided around each structure, Eg. greenhouse,

tank, pump and to the boundary of the available area

• One corner of the greenhouse must be positioned in the lower right corner of the available

area (as shown in Figure 1)

• The greenhouse must fit within the shaded area (outer dimensions A= 15 m x B= 10 m)

Relevant assumptions / simplifications

• The thickness of the frame and sheeting which form the greenhouse is to be ignored

Table 1. Technical data relevant to greenhouse and grow tables

quantity variable value unit

Cost of grow tables – small ST, large LT

CST

CLT

100

180 $ each

Cost of greenhouse –

(per square metre surface area) Cg

See table 7 $/m2


2.2. Section 2 – Storage Tank The plants in the greenhouse are to be grow hydroponically. This is achieved by pumping nutrient

enriched water from the storage tank into the grow trays periodically each day, then pumping most

of that water back into the storage tank. To keep the system very simple and keep costs low, a single

pump and one set of piping will be used to fill and empty all grow trays at the same time. Details of

the pump and piping will be provided in Section 3.

To effectively water the plants all grow trays must be flooded to a depth of 100 mm. To ensure

sufficient water is available - the minimum volume (W) of water held in the storage tank (at all times)

is to be twice the volume required to flood all the grow trays to the required level. Water and nutrient

consumed by the plants each week will be 35% of the total volume of the grow trays. At the start

of each week the tank is topped up (completely full) with water and nutrient.

The storage tank is to be cylindrical (closed each end) and positioned within the available area such

that it minimises the length of pipe work. The cost of the tank is proportional to its surface area.

The storage tank defined by the parameters:

• D – the diameter (m) of the tank

• H – the height (m) of the tank

• W – the minimum volume (L litres) of water held in the tank

• U – the volume (L) of water used by the plants each week

• V – the volume (L) of the tank

• AT – the surface area of the storage tank (m2)


• The relationship between number of grow tables (NS NL) and minimum volume (W)

• The equation for the volume of water the plants use (U)

• The equation for the volume of water storage tank (V)

• Suitable values for D and H

• The equation for the surface area (AT) of the storage tank


• The maximum height for the storage tank is to be 2.5 m


• The thickness of the material the storage tank is made of, is to be ignored

• The density of the nutrient/water mix is the same as water

Table 2. Technical data relevant to storage tank


Density of nutrient/water mix ρW 1000 kg/m3

Cost of storage tank

(per square metre surface area) Cs

50 $/m2


2.3. Section 3 –Pump and Piping One pump and a set of pipes are required to move nutrient enriched water from the storage tank into

the grow trays periodically each day and return most of that water back into the storage tank. A single

pump and a set of piping will be used to fill and empty all grow trays at the same time. Details of the

storage tank are provided in Section 2.

To effectively water the plants all grow trays must be flooded to a depth of 100 mm. The plants are

to be watered 4 times per day at 09:00, 11:00, 13:00 and 15:00 hrs. So the plants are not over-watered,

the trays must fill within a 15 minute period, retain the water/nutrient solution for 10 minutes and

drain within 15 minutes. The velocity of flow into each grow tray is not to exceed 1 m/s

The type of pump proposed for the system is capable of pumping in either direction. One side of the

pump is connected to the outlet at the bottom of the storage tank, the other side is connected through

a filter and an electrically controlled valve, to a set of polyethylene pipes which connect to the

centre of the bottom of each grow tray. The centreline of the pipes is to be 100mm below ground

level. The pump enclosure and storage tanks are set into the ground by 200 mm to allow the exit of

the piping at the required depth. All pipes are to be run in straight lines parallel or perpendicular to

the sides of the greenhouse, so bends and branches must be at right angles. See Figure 2.

Figure 2. Storage tank, pump, filter, valve and grow tray connection.

The pump is actually comprised of an electric motor and a pump mechanism. The output of the

motor directly drives the pump mechanism. A range of motor models are available which have

different output (rated) power. The speed (S in rpm) of these motors can be controlled as required.

The ‘head’ (height difference) between the water in the storage tank, pipes and grow trays varies, but

is always less than the height of the storage tank. For this system a constant head equal to the twice

the height of the storage tank (2H) is to be assumed when determining the power rating of the

pump.

The required power to be input to the pump mechanism is determined from the general equation:

P = Q * Head * g * ρ / η (where all quantities are in SI units)

The cost of the motor is dependent on which motor is selected. See Table 4.

The cost of the piping is dependent on length and chosen diameter. Most piping only comes in 50 m

rolls. See Table 5.

min spacing s = 0.8 m

pump, filter, valve

1 m cube

Note: not to scale isometric view

side view detail

100 mm

storage tank

table height 0.75 m

grow tables

ground level


The motor-pump combination is defined by the parameters:

• Q – required flow rate (L/min)

• η – the efficiency of the pump mechanism

• P – the output power rating of the motor (W)

• M-n – the motor model selected

• S – the speed of the motor (rpm)

• v – the volume (L) of fluid delivered by the pump mechanism per revolution

The piping is defined by the parameters:

• d – the internal diameter (mm) of the pipe

• l – the length of the pipe (m)

• q – the flow rate in the pipe (L/min)

• P-n – the pipe type(s) selected


• The relationship between number of grow tables (NS NL) and the required flow rate (Q)

• The power requirement for the motor (P)

• A suitable choice of motor (M-n)

• The relationship between the length (L) & radius (R) of the greenhouse and the length (l) of

and size of pipe (P-n) required

• A suitable choice of pipe sizes and lengths for the proposed layout


• A constant head equal to 2H, twice the height of the tank is to be used

• The velocity of flow into the grow trays is not to exceed 1 m/s

• All pipes are to be run in straight lines parallel or perpendicular to the sides of the

greenhouse

• Only right angle bends and branches are to be used


• Fittings for bends, branches and connections are NOT to be considered

• Loss of pressure due to fittings and the length of pipe is to be ignored

• The lengths of pipe are to ignore the size of fittings, bends etc

Table 3. Technical data relevant to pump and piping


Density of nutrient/water mix ρW 1000 kg/m3

Efficiency of the pump mechanism η 0.83 -

volume delivered per revolution of pump v 0.6 L

Cost of the pumping mechanism CPM $500 -


Table 4. Available motors and costs

Motor model Output Power rating (W) Cost

M-1 100 $500

M-2 200 $900

M-3 300 $1300

M-4 400 $1700

Table 5. Available pipe types and flow rates

Pipe type

Pipe internal diameter

(mm)

Maximum flow rate

(L/min)

Cost

($ / 50m roll)

P-1 20 33 $ 90

P-2 25 58 $120

P-3 32 96 $150

P-4

55 300

Available by the metre at

$5 / m


2.4. Section 4 – Greenhouse sheeting and temperature control For optimum growing conditions the temperature in the greenhouse is to be maintained at

25°C during the day and no less than 15°C at night. (night is defined as a 12 hour period)

During the day the temperature is automatically maintained at 25°C by opening sections of the

sheeting which form the curved greenhouse roof. (How that is achieved is outside the scope of this

Client Brief and not part of the assignment)

During the day heat energy is absorbed into a layer of gravel (of depth dg) which forms the floor of

the entire green house. See Figure 3. This layer of gravel is installed below ground level and is

insulated from the ground by a thermal lining. At sunset the greenhouse is closed and the

temperature of the gravel will be at 25°C. The specifications of the gravel are provided in Table 6.

(All materials inside the greenhouse would absorb heat energy – ie. the air, the tables and the

plants, however the thermal mass of those materials has been determined at less than 1% of the

thermal mass of the gravel and hence only the gravel is significant in this design. The thermal lining

is considered as ídeal’ and hence no energy is transferred to or from the ground.)

During the night the temperature outside the green house decreases and heat energy is lost by

conduction through the plastic sheeting which forms the surface of the green house. The

temperature outside the greenhouse actually varies during the night and with the seasons, however

the average temperature difference (Tin – Tout) has been determined as 10°C.

The temperature inside the greenhouse is assumed to be the same as the gravel at all times.

(The constant temperature difference of 10°C is to be used for conduction calculations.)

The sheeting on the greenhouse is a new polycarbonate based composite material which provides a

lower thermal conductivity then standard polycarbonate. The specifications of the two available

sheet types are provided in Table 7.

Figure 3. Gravel floor

The gravel is defined by the parameters:

• dg – the depth of the gravel (mm)

• Vg – the volume of gravel (m3)

• ρG – the density of the gravel (kg/m3)

• mg – mass of the gravel (kg)

• c – the specific heat value ( J/(kg·K) ) of the gravel

• Eth – the thermal energy (MJ) lost from the gravel during the night

Note: not to scale

pipe depth 100 mm

table height 0.75 m

gravel depth dg

ground level

thermal lining


The plastic sheeting is defined by the parameters:

• As – the surface area of the green house (m2)

• S-n – the sheet type selected

• t – the thickness (mm) of the sheet type selected

• k – the thermal conductivity of the selected sheeting

• qs – the heat transfer rate (W) through the sheeting

• T – the time (hr) taken for the gravel temperature to drop from 25°C to 15°C


• The relationship between gravel depth (dg), R and L for the greenhouse and the volume of

gravel (Vg)

• The relationship between the volume of gravel (Vg) and mass of gravel (mg)

• The relationship between the mass of gravel (mg) and the thermal energy (Eth)

• The relationship between As, the selected sheet type and the heat transfer rate qs

• The relationship between the heat transfer rate (qs), the thermal energy (Eth) and the time

(T)


• The minimum depth of gravel needed to create a practical floor is 75 mm

• The maximum depth of gravel able to be installed is 200 mm

• The minimum inside temperature in the green house is to be 15°C

• The inside temperature must remain above 15°C for a minimum period of 12 hours.


• The temperature inside the greenhouse is assumed to be the same as the gravel at all times

• The average temperature difference (Tin – Tout) is to be 10°C

• The costing for the sheeting includes the supporting frame and doors

• The cost of the thermal lining is to be ignored

Table 6. Technical data relevant to the gravel and sheeting


Density of gravel (actual not bulk density) ρG 1800 kg/m3

Specific heat value for gravel c 900 J/(kg·K)

Cost of gravel (delivered and installed) CG 80 $/m3

Table 7. Available sheet types

Sheet type

Sheet thickness

(mm)

Thermal conductivity

k ( W/(m·K) )

Cost

($ / m2)

S-1 10 0.025 $ 40

S-2 15 0.025 $ 55


2.5. Section 5 – Costing and Budget

The budget allocated to cover all components outlined in Sections 1 to 4 above is $12,000.

The total cost is to be stated as Ctotal.

The cost of the components of the project are to be individually stated as:

• Cgreen – cost of the green house (sheeting)

• Cgrow – cost of the grow tables

• Ctank – cost of the tank

• Cgrav – cost of the gravel

• Cmotor – cost of selected motor

• Cpump – cost of the pump

• Cpipe – cost of the piping

3. Project Goals Self Sufficient Lodge is founded on the principles of the efficient utilisation of natural resources.

Thus the stated goals of this project are:

G1. Provide the maximum possible grow table area in the most cost effective way

G2. Where possible allow for higher flow rates into the grow trays

4. Project Requirements The project is expected to meet the following requirements:

R1. Do not exceed the allocated budget for the project (of $12000)

R2. Provide a minimum of 25 m2 of grow table area


Important note to students

The sections listed above are to be used to subdivide the analysis and design process and

identify the sections you are to use for your Technical Analysis Report, Presentation and

Design Proposal, as detailed in the requirements of the TAP and DP assessments.

IMPORTANT: This is a closed design problem where all information required to

complete the technical analysis, calculations and evaluation of possible solutions will be

available in the Client Brief, your text books or other provided assignment material. The

problem presented is a simplified version of a real design problem, so the more complex

aspects and fine details of the components of the proposed system are ignored.

If you find yourself seeking information beyond that provided in the Client Brief, your

text books or other assignment material then you are probably over thinking the

problem. The three assessments using this problem are able to be completed using just the

engineering fundamentals you are studying, supported by other course material and tools

like the spreadsheet. There is no need to research commercial equipment.

For the technical analysis report all students must complete a technical analysis and

prepare a short technical report on design section 1 (only) of the project.

For the presentation each student will select design section 2 or 3 of the project on which

to complete a technical analysis and prepare a short oral presentation. You are to

present a summarised technical analysis of that section of the design and how it links to

section 1 of the design. The presentation is to be prepared and delivered as if it was to be

delivered to colleagues in your company who are working with you on the larger project.

For the Design Proposal assessment students are expected to complete the technical

analysis for the whole project, model the design on a spreadsheet, evaluate some

alternatives within the design and select a specific design solution to recommend in their

report. The recommendation must clearly specify all of the parameters listed in the design

sections in bold, as they define each section of the design.

Students should note there is more than one correct answer to this problem, as several

possible solutions will meet the requirements of the design. You are NOT expected to find

an optimum solution, but simply to identify where the better solutions are across the

possible solution space (defined by a range of parameters) and recommend one solution.

Furthermore - a technical analysis of a single design section ALONE is unlikely to

identify a set of design parameters that results in a workable final design, as the

sections are somewhat dependent on each other. Hence when you complete a technical

analysis on a single section of the design you are not looking for a specific single

‘answer’, but identifying the range of parameters that meet the requirements of that section.

The staged release of a Version 1 and a Version 2 of the Client Brief is intended to

discourage students from trying to ‘solve’ the whole problem at once, because some

students try to present a single ‘best case’ as the outcome of an analysis of a single section.

Your analysis should show the relationships between the parameters within each

section and possibly with those in other sections of the design. This analysis will allow

you to eliminate some of the alternative equipment suggested (when it is evident it cannot

do the job), or you may be able to reduce the range of values for some parameters which

offer a possible solution.


Company Profiles and addresses

Amorphous Systems – family surnames beginning with A - E

Priding itself on its versatility and broad industry experience, this consulting firm will confidently

tackle any project in the engineering and spatial science fields.

Amorphous Systems

11 Doncaster St

Broadmeadow NSW

Australia 2430

Brilliance in Mind – family surnames beginning with F - J

The research and development prowess of this small but dynamic group is second to none in the

industry. Teamed with their project management subsidiary they are a force to be reckoned with.

Brilliance in Mind

22 Pamela Drv

Dandenong VIC

Australia 3175

Creativation – family surnames beginning with K - O

As a spin off company of the commercial side of CSIRO, this company has access to the largest

group of government contractors and some of the greatest academic minds in the country.

Creativation

33 Zeppa Ct

Mirrabooka WA

Australia 6061

Domineering – family surnames beginning with P - S

This multi-national consultancy runs several teams of highly experienced engineering and spatial

science professionals, setup to take on projects large and small, any where in the world, at a

moments notice.

Domineering

44 Prime Minister Ave

Watson ACT

Australia 2602

Exemplar Designs – family surnames beginning with T - Z

Sometimes considered the underdog in the engineering and spatial science industry, this company

continues to punch way above it weight and is fast earning the respect of many industry players, due

to its recent successes.

Exemplar Designs

55 Technic Way

Newstead QLD

Australia 4006

eng1002 design project client brief - version 2 · eng1002 design project – s2 2017 – v2 1...

Documents