# ME 144 – Sustainable & Renewable Energy Systems Course Project ## **Solar Powered Chilled Water System for HVAC Applications** --- ## **Step 1: Calculate the Cooling Load for the Chilled Water System** **Given:** - Mass flow rate of water (\( \dot{m}_w \)) = 15 kg/s - Water inlet temperature (\( T_{in} \)) = 15°C - Water outlet temperature (\( T_{out} \)) = 10°C - Specific heat of water (\( c_p \)) ≈ 4.18 kJ/kg·K **Formula:** \[ Q_{cooling} = \dot{m}_w \times c_p \times (T_{in} - T_{out}) \] **Calculation:** \[ Q_{cooling} = 15 \times 4.18 \times (15 - 10) \] \[ Q_{cooling} = 15 \times 4.18 \times 5 \] \[ Q_{cooling} = 15 \times 20.9 \] \[ Q_{cooling} = 313.5 \text{ kW} \] **Example:** If you needed to chill 20 kg/s from 18°C to 10°C: \[ Q_{cooling} = 20 \times 4.18 \times (18 - 10) = 20 \times 4.18 \times 8 = 668.8 \text{ kW} \] --- ## **Step 2: Sketch the Refrigeration System Cycle Diagram** Below is a simplified schematic representation (graph) based on the provided description: ``` [Evaporator] --(saturated vapor)--> [Compressor] --(superheated vapor)--> [Condenser] --(saturated liquid)--> [Expansion Valve] --(low-pressure liquid)--> [Evaporator] ... ``` - **Evaporator:** Absorbs heat from chilled water (4°C, saturated vapor R134a) - **Compressor:** Raises pressure to 1 MPa, superheats vapor - **Condenser:** Rejects heat to cooling tower water, condenses to saturated liquid - **Expansion Valve:** Drops pressure, refrigerant returns to evaporator **Graphical Representation:**  *Alt text: Schematic of Solar Powered Chilled Water System with labeled evaporator, compressor, condenser, and expansion valve.* --- ## **Final Answer** ### **1. The cooling load for the chilled water system is** \[ \boxed{313.5\ \text{kW}} \] ### **2. Cycle steps are shown in the schematic above.** --- ## **Summary Table** | Step | Description | Example Calculation | |-----------------|--------------------------------------------------|-------------------------------| | 1. Cooling Load | \(Q = \dot{m}_w c_p (T_{in}-T_{out})\) | \(313.5\) kW | | 2. Cycle Steps | Evaporator → Compressor → Condenser → Expansion | See schematic above | --- If you need a detailed thermodynamic state table or further calculations (such as COP), let me know!

# ME 144 – Sustainable & Renewable Energy Systems Course Project ## **Solar Powered Chilled Water System for HVAC Applications** --- ## **Step 1: Calculate the Cooling Load for the Chilled Water System** **Given:** - Mass flow rate of water (\( \dot{m}_w \)) = 15 kg/s - Water inlet temperature (\( T_{in} \)) = 15°C - Water outlet temperature (\( T_{out} \)) = 10°C - Specific heat of water (\( c_p \)) ≈ 4.18 kJ/kg·K **Formula:** \[ Q_{cooling} = \dot{m}_w \times c_p \times (T_{in} - T_{out}) \] **Calculation:** \[ Q_{cooling} = 15 \times 4.18 \times (15 - 10) \] \[ Q_{cooling} = 15 \times 4.18 \times 5 \] \[ Q_{cooling} = 15 \times 20.9 \] \[ Q_{cooling} = 313.5 \text{ kW} \] **Example:** If you needed to chill 20 kg/s from 18°C to 10°C: \[ Q_{cooling} = 20 \times 4.18 \times (18 - 10) = 20 \times 4.18 \times 8 = 668.8 \text{ kW} \] --- ## **Step 2: Sketch the Refrigeration System Cycle Diagram** ### **System Components:** 1. **Evaporator:** Absorbs heat from chilled water (4°C, saturated vapor R134a) 2. **Compressor:** Raises pressure to 1 MPa, superheats vapor 3. **Condenser:** Rejects heat to cooling tower water, condenses to saturated liquid 4. **Expansion Valve:** Drops pressure, refrigerant returns to evaporator ### **Cycle Diagram:** ``` [Evaporator] --(saturated vapor)--> [Compressor] --(superheated vapor)--> [Condenser] --(saturated liquid)--> [Expansion Valve] --(low-pressure liquid)--> [Evaporator] ... ``` **Graphical Representation:**  *Alt text: Schematic of Solar Powered Chilled Water System with labeled evaporator, compressor, condenser, and expansion valve.* --- ## **Final Answer** ### **1. The cooling load for the chilled water system is** \[ \boxed{313.5\ \text{kW}} \] ### **2. Cycle steps are shown in the schematic above.** --- ## **Summary Table** | Step | Description | Example Calculation | |-----------------|--------------------------------------------------|-------------------------------| | 1. Cooling Load | \(Q = \dot{m}_w c_p (T_{in}-T_{out})\) | \(313.5\) kW | | 2. Cycle Steps | Evaporator → Compressor → Condenser → Expansion | See schematic above | --- If you require further calculations, such as Coefficient of Performance (COP) or detailed thermodynamic properties, please let me know!