Page 14 - Low Temperature Energy Systems with Applications of Renewable Energy

Principles and operation of refrigeration and heat pump systems 3

losses. Low-temperature technologies should be characterized by a high degree of en-
ergy efficiency, since with a decrease in the temperature of the source of heat, the cost
of equipment for energy conversion systems increases and the attractiveness of inno-

vative projects decreases. Sources with a temperature of up to 100 C are sources for
the application of heat pump systems that provide savings and replacement of organic

fuel by 1.5e2.0 times or more. Sources with temperatures above 100 C can be used as
sources for heat-using refrigeration machines (i.e., absorption systems), in heat ex-
changers in cogeneration and systems, as well as in vapor-powered organic cycles
(ORC cycles) for generating electricity and heat. A promising direction is the creation
of hybrid low-temperature power plants using RES (solar, hydro, geothermal, wind
and bioenergy) as well as waste heat of industrial enterprises and household sources.
The main shortcomings of renewable energy sources are the low energy density of
flows and their inconstancy over time, dependence on natural and geographical factors,
whereas their advantage is their distributed nature that does not require extensive infra-
structure for local consumption, which in combination with high-tech, low-
temperature energy systems ensures their more efficient use.

1.2 Worldwide energy saving policies

All industrialized countries have applied energy-saving laws that meet specific local
conditions in practice since the 1970s. For example, Sweden is pursuing all energy
conservation activities on the basis of the “Energy Saving Code” (1977e80); France e
on the basis of the “Law on Energy Savings” (1980); Germany e on the basis of the
“Law on Energy Saving” (1979); Japan e based on the “Law on the rational use of
energy” (1979) [11]. The main laws governing the industry in USA are National En-
ergy Act (1978), Public Utility Regulatory Policies Act (PURPA), Energy Policy Act
(1992), and the Energy Independence and Security Act (2007).
The regulatory framework in the EU countries provides the design of the construc-
tion and operation of heating and cooling systems using heat pump units. Currently,
the following standards are applied:
1. DIN 8901-2002. Refrigerating systems and heat pumps. Safety and environment require-
ments and testing.
2. DIN EN 378-1, 2, 3, 4 e 2017. Refrigerating systems and heat pumps. Safety and environ-
mental requirements.
3. DIN EN 13313 e 2011. Refrigerating systems and heat pumps. Competence of personnel.
4. DIN EN 14511-1, 2, 3, 4 e 2013. Air conditioners, liquid chilling packages and heat pumps
with electrically driven compressors for space heating and cooling.
5. DIN EN 14825 e 2016. Testing and rating at part load conditions and calculation of sea-
sonal performance.
6. DIN EN 15879 e 2011. Testing and rating of direct exchange ground coupled heat pumps
with electrically driven compressors for space heating and/or cooling. Part 1.
7. DIN EN 16905-1 (3-5) e 2017. Gas-fired endothermic engine driven heat pump. Part 1, 3,
4, 5.