a) You are describing some ground test results to the client concerning the permeability of the site and its hydraulic c

[answerhappygod]

A You Are Describing Some Ground Test Results To The Client Concerning The Permeability Of The Site And Its Hydraulic C 1 (156.18 KiB) Viewed 34 times

a) You are describing some ground test results to the client concerning the permeability of the site and its hydraulic conductivity. The client is confused by the terminology, can you explain to them the difference between hydraulic conductivity and permeability? [2 marks] b) Next, you tell them that two samples from the site are found to have identical values of absolute porosity. The client is pleased because they assume this means that no more testing will be required and they can save some money from their project budget. Please explain to the client why identical values of porosity in the two samples does not guarantee that fluid flow behaviour will be the same? Please also explain why trying to save money by minimising the survey activities may not be cost effective in the long term. [2 marks] c) To improve the viability of the project, the client would like to use some of the geothermal fluid to directly heat the power plant site office. Please explain to the client why it is not a good idea to run the geothermal fluid directly through the heating system of the building. [1 mark] Page 4 of 5 d) You think the principle is good so instead you suggest using a heat pump to indirectly capture the heat from the geothermal fluid. Your proposed layout is sketched in Fig. 1. The heating demand of the building is 500 kW. You decide that Ammonia (NH3​) is the most suitable refrigerant to use as the working fluid in the heat pump. The compressor is designed with an isentropic efficiency of 75% whereas the condenser is assumed to be 100% efficient. Calculate the mass flow rate of the Ammonia working fluid, m˙wf​, required to meet the heating demand of the building. [12 marks] e) At what temperature is the geothermal fluid returned to the ground? [3 marks] f) What is the value of the Coefficient of Performance (COP) of the designed system? [2 marks] g) The client is unfamiliar with heat pumps and thinks that a conventional heating system using natural gas might be better. Basing your argument around the COP, explain to the client what the main benefits of using a heat pump system are compared to conventional heating systems utilising fossil fuels.