Ruzhu WANG Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University
Heat pump innovations and its role in 2060 China Carbon Neutral Strategies
The world is facing carbon neutral in the middle of this century, carbon neutral does not mean zero carbon emission, it means carbon emission could be absorbed by carbon sink. It is clear that the world will be more powered by renewable energy (50% or more in 2050), electrification would be affordable and accessible and could be extended its applications. Fossil fuel should be treated for less CO2 emission by increasing energy conversion efficiency, and wide uses of heat recovery devices to use low grade heat both from waste heat or solar heat or even from the ambient becomes vital. Heating and cooling are the most demanded energy for end users, such as buildings, industries and also transportations, heat pump is truly the most effective equipment for decarbonization.
This report will present 1. Heat pumps based on electric vapor compression systems: air source heat pump water heater, air source heat pump heating and cooling for residential and commercial buildings, other various low grade heat source heat pump (such as ground source, water source and etc..), waste heat recovery heat pump for industry heating; 2. Heat pump based on thermal driven systems: LiBr-water and water-ammonia absorption heat pumps for efficient waste heat recovery for industry application, and solar cooling; 3. Chemical heat pumps based on thermal energy for heating, cooling, thermal energy upgrading, and thermal storage; 4. Next generation heat pumps for air conditioning with coupled sensible and latent thermal load handling, its doubled efficiency for heating and cooling could be applied in residential/commercial/transportation heating and cooling; 5. Air source heat pump or waste heat recovery heat pump for steam generation, which may bring a new feasible way to use electrified heat pump to replace small to medium scale fossil fuel based or electric heated boilers.
Heating/cooling decarbonization is a major challenge for China to meet its 2060 carbon neutral commitment, heat pump represents a promising solution for heat/cold supply in various building and industry applications. Our results reveal that the decarbonization potential from heat pump in a carbon neutral China future could reach around 1400Mton and 600Mton for residential and industrial heating respectively, which add to 20% current carbon emission in China. It is also shown that achieving such deep decarbonization of heat pump requires ad-hoc interventions that balance technology advancement, techno economics, policy incentive, and integrated short-term and long-term decision making. This research has shown that heat pump could play a key role in carbon neutral target.
Shin-ichi Tanabe Department of Architecture, Waseda University
Indoor Environment, ZEB, and Carbon Neutral Society
The indoor environments should enhance occupant’s health, comfort and productivity bucause people spend around 90% of their lives indoors. However, energy policy and carbon neutral goals in many countries are often focused only on the implementation of measurable energy savings in buildings without taking into account the satisfactions for building users. This has been changed that the energy in buildings should be reduced without compromising the indoor environmental quality. We have to clear the effects of indoor environment in terms of both health and productivity by the scientific evidences. A lot of developping countries declare to establish carbon neutral society until 2050. At the same time we have to think sustainable solutions to persuade clients to accept the concept of a relationship between indoor environmental quality and economic productivity benefits. Human centreed research is required to solve these problems. Latest tends in the world and in Japan are intruduced and discusseed.
Piotr A. Domanski National Institute of Standards and Technology
An Update on Low-GWP Refrigerants
Within the last 50 years the refrigeration sector, including air conditioning, experienced an extraordinary growth driven by the economic and population growth, particularly in developing countries. Great technological advances were achieved over the years driven by competitive market forces (equipment is more reliable, more efficient and smarter). However, a very extensive R&D effort has been also expended to respond to global environmental requirement to use refrigerants that would not damage the ozone layer and have a low global warming potential (GWP). The presentation provides a historical perspective and a summary of the screening process for medium- and high-pressure fluids indicating that the probability of finding new low-GWP fluids is minimal. A review of available low-GWP single-compound refrigerants and blends for different applications follows. Rather limited options for unitary air conditioning (using R-410A) and commercial refrigeration (using R-404A) are highlighted as several identified hydrofluoroolefins (HFOs), successfully used in low- and medium-pressure systems, do not have a normal boiling point low enough for high-pressure applications. This precludes their use unless they are blended with low-temperature boiling fluids, which have a much higher GWP (except hydrocarbons). The discussed merits include coefficient of performance, volumetric capacity, GWP, flammability, and two-phase temperature glide. The presentation also discusses the trade-off between GWP and flammability, and the latest fluids under consideration. Due to trade-offs between different refrigerant attributes the product offerings will undergo increasing fragmentation with multiple refrigerants used depending on regional preferences or equipment size.
William P. Bahnfleth The Pennsylvania State University
Indoor Air Quality after COVID
The COVID-19 pandemic has not only disrupted life around the world and caused millions of deaths. It has also prompted a deep reassessment of what constitutes acceptable indoor air quality. Efforts to implement engineering controls to make buildings safer have in many cases proved costly, energy intensive, and difficult to validate. In short, buildings designed in the conventional way have not proved very resilient. A major factor contributing to this experience is the current status of design standards, which in general do not address resilience with respect to both epidemic disease outbreaks and natural disasters such as wildfires. Equally important is the lack of explicit consideration of airborne infection risk in standards. While ventilation and filtration have demonstrated effectiveness for airborne infection control, understanding about other promising technologies that could help to limit adverse energy use impacts while achieving lower risk. Indeed, it is also widely acknowledged that minimum standards significantly underperform in terms of providing a generally healthy and productive indoor environment. Many strongly believe that the definition of acceptable indoor air quality needs to change to address both wellness and resilience. This presentation reviews the current status of indoor air quality, how that paradigm may shift in the future, and how that can be done sustainably.