So my chosen refrigerant is R-32. I'm having trouble finding a good range of pressure and temperature that takes the isentropic efficiency into account. I was using the software,EES, as my source of property retrieval since I couldn't find properties of R-32 anywhere else. Project Overview:A geothermal heat pump or 'ground source heatpump,' is a highly efficient renewable energytechnology that is becoming popularized for bothresidential and commercial buildings. Geothermalheat pumps are used for space heating, and can alsobe used for water heating. Because the earth'stemperature 5-10 feet below ground level remainsat a relatively constant temperature throughout theyear, the benefit of geothermal systems is that theyconcentrate naturally-existing heat, rather than byproducing heat through the combustion of fossilfuels. ¹ENES232 Thermodynamics: Geothermal Heat Pump Cycle Design●EH●FEEFASource: https://www.climatemaster.com/news/energy-bills/2018-You are tasked with designing a geothermal heat pump system for a residential home that requires 3.5 tons(12.3 kW) of heating capacity. As part of the design, the geothermal heat pump system will also provideenergy to the house's hot water heater. You are asked to design a system that provides at least 12.3 kW ofheating capacity to the forced air heating system of the home on an average winters day, when thetemperature of the buried water/antifreeze lines of the geothermal loop can be assumed to be 12°C and thetemperature of the outside air can be assumed to be 0°C. The intent is to keep the house's forced air at orabove a temperature of 21°C. The hot-water heater should be able to heat water to a temperature of 48°C.07-11-geothermal-heating-and-cooling-for-your-homeFor an explanation of geothermal heat pumps, you can watch this video provided from the US DOE. Foran example of what components are needed in a residential geothermal heat pump system used for waterand air heating, reference this example that shows a geothermal system used to heat both forced air and hotwater. (Note: the operating conditions shown in this example do not meet the specifications of this project,SO not attempt to copy/paste the example directly for your design!)When designing the residential heat pump cycle, you can make the following assumptions:● The cycle is operating at steady-state conditionsThe compressor operates adiabatically with an isentropic compressor efficiency of ns,c = 82%The refrigerant enters the compressor as a saturated vapor (x = 1)0)The refrigerant enters the expansion valve (throttling process) as either a saturated liquid (x =or a compressed liquid [this is a design choice]You can ignore pressure drops in piping of the system or in the lines of the heat exchangersProject Expectations:As the design engineer, you are asked to first scope the heat pump cycle's operating conditions, analyze thefeasibil of the geothermal heat pump system for the home owners, and analyze the environmental impactand safety of the system you are designing. Once this preliminary design is properly scoped, you are thentasked with designing and analyzing a geothermal heat pump system that meet's the home owners' needs.Your project is broken into two distinct milestones: (4) Preliminary design operating considerations: given the necessary/given temperatures of theforced air (21°C), the hot water (48°C), and the geothermal water/antifreeze loop (12 °C) in theintroduction:a. Temperature considerations:i. What is the necessary temperature range of the refrigerant when passing throughthe evaporator (this should be a range of allowable temperatures, not one temp.)?ii. What is the necessary temperature range of the refrigerant when passing throughthe hot water heater (this should be a range of temperatures, not one temperature)?iii. What is the necessary temperature range of the refrigerant when passing throughthe forced air system (this should be a range of temperature, not one temperature)?b. Pressure considerations: based on the temperatures you've identified above, the projectassumptions and the refrigerant that you have chosen in part (3):i. What is the allowable pressure range of the refrigerant when passing through theevaporator?ENES232 Thermodynamics: Geothermal Heat Pump Cycle Designii. What is the allowable pressure range of the refrigerant at the compressor outlet?(Remember, this is the pressure at both the hot water heater and the forced airsystem)** NOTE: The isentropic efficiency should be accounted for when determining the highpressure in the system

Question

Accepted Answer

It is asked to design the heat pump based on the given design criteria

Required heat demand = 12.3…