Advanced HVAC Technologies. Electricity Producing Air Conditioning (E-HVAC) Integrated Power Generation and Liquid Desiccant HVAC System

Transcription

1 Advanced HVAC Technologies Electricity Producing Air Conditioning (E-HVAC) Integrated Power Generation and Liquid Desiccant HVAC System Daniel A. Betts Be Power Tech, Inc. August 16, 2017 Tampa Convention Center Tampa, Florida

2 Learning Objectives 1. Understanding of HVAC s Greenhouse Gas Impact 2. Understanding the impact of HVAC in implementation of renewable energy systems 3. Understanding the potential impact of the integration of liquid desiccant HVAC technology with power generation technology 2

3 The Air Conditioning Challenges Refrigerants are powerful GHG Air Conditioning drives peak electrical demand and it is out-of-synch with peak renewable energy generation Inefficient humidity control 3

4 Refrigerants & GHG Estimated Global GHG Emissions Associated with Air Conditioning 700 Million CO 2,eq 74% Electricity Consumption 26% Refrigerants Common refrigerants have high GWP: Example: R410a has a GWP of 1,900 Source: Workshop: Future Non-Traditional Air Conditioning (and Heating) Technologies for Buildings, 2017 EIA International Heat Pump Conference, 5/15/17 4

5 5 The Renewable Electricity Challenge Supply for Electricity Must Equal Demand for Electricity Renewable Electricity Supply is Uncertain, Intermittent & Variable

6 Air Conditioning Impact on Electrical Demand Afternoon air conditioning electrical demand is out of phase with solar power generation 6

7 The Duck Curve The Challenge: Increased renewable deployment requires peaking plants (spinning reserves) and battery energy storage. Both are expensive and have low asset utilization 7

8 Existing Solutions Grid Scale Battery Energy Storage System Natural Gas Peaking Plant Source: AES Energy Storage Source: Inside Edison.com 8

9 E-HVAC: Electricity Producing HVAC Technology E-HVAC: 5-ton / 5kW Concept Heat Air Conditioning 5 tons (5 kw) Electricity 5kW 60,000 kwh/year No refrigerant Eliminates AC demand Produces electricity Acts as baseload and as spinning reserve 9

10 E-HVAC Technology High Efficiency Power Generator Thermal Energy Storage Liquid Desiccant HVAC 10

11 E-HVAC - General Operation Natural Gas Power Generation Electrical Power Heat Liquid Desiccant Regeneration Hot, Humid Air Condenser High Concentration Liquid Desiccant Tank Warm, Humid Air Enhanced Liquid Desiccant Air Conditioning (ELD-A/C) Cool, Low Humidity Air Low Concentration Liquid Desiccant Tank Water 11

12 Key Points 1. Timing of power generation & A/C operation are partially decoupled The heat from power generation is captured in a highly efficient manner even when air conditioning isn t on Heat is converted to an electrical equivalent output (electricity has higher value than heat) 2. Size of power generation unit (power output) is partially decoupled from cooling output (tonnage) Size of energy storage tank can determine power generation size 12

13 Integrated System Operation 13

14 E-HVAC Testing at Oak Ridge National Laboratory (ORNL) Prototype unit undergoing test Integrated prototype unit was developed in 2016 Unit was tested at ORNL from February 2017 to April 2017 ORNL test used two environmental chambers to emulate outdoor air and return air conditions 14

15 System Performance 15

16 Test Results: High Temperature / High Humidity Outdoor Air: 32 o C / 72%rh Return Air: 25.1 o C / 56%rh 1 st Law Efficiency = 91% There s room for improvement. The ideal process is shown in red 16

17 More Useful Efficiency Definition While the 1 st Law Efficiency enables analysis of how well the chemical energy of the fuel is converted into useful energy, it does not enable comparison with other devices. It is useful to define an efficiency that enables comparison of the E-HVAC performance with that of Distributed Power Generation System: Distributed Power Efficiency: Vapor compression system can a COP higher than one, thus this definition will be lower than the 1 st Law Efficiency 17

18 Distributed Generation Electrical Efficiency High Temperature / High Humidity Condition Fuel cell is unable to provide enough heat to drive the ELD-A/C process. Excess natural gas must be burned to maintain air conditioning output. Not the case with Internal Combustion 18 Duty Cycle: Amount of Time A/C Operates / Amount of Time Power Generator Operates Fuel Cell Efficiency = 47% Internal Combustion Generator Efficiency = 30%

19 High Temperature / Low Humidity Case Outdoor Air: 38 o C / 30%rh Return Air: 25.5 o C / 55%rh 1 st Law Efficiency = 129% 19

20 Distributed Generation Electrical Efficiency High Temperature / High Humidity Condition 20

21 Primary Energy Savings Potential Results Analysis E-HVAC is potentially the most impactful HVAC technology Source: ORNL/TM-2017/211 21