Improving a heat supply system by increasing the efficiency of the heat pump unit

Abstract The reliability and efficiency of the operation of district heating systems is largely determined by the efficiency of preparation of heating network water. In open heat supply systems, make-up water, among other things, compensates for the water intake in hot water supply systems. A number of technologies have been developed that increase the efficiency of an open heat supply system by reducing the water consumption in the supply pipeline of the heating network, increasing the operating time of the heat pump, and increasing the specific generation of electricity for heat consumption at the CHP plant due to additional cooling of the network water in the return pipe of the heating network.

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Development of Single Loop Heat Supply System for Local Community Cogeneration: Prototype Test of a Heat Supply Unit With Heat Storage and Tap Water Preheating by Heat Pump Unit

ASME 2005 Power Conference ◽

10.1115/pwr2005-50372 ◽

2005 ◽

Author(s):

Hitoshi Asano ◽

Terushige Fujii ◽

Yoshinori Hisazumi ◽

Toshihiro Hori ◽

Tetsuo Abiko

Keyword(s):

Heat Pump ◽

Management System ◽

Heat Supply ◽

Local Community ◽

Heat Storage ◽

Tap Water ◽

Heat Supply System ◽

Supply System ◽

Hot Water ◽

Single Loop

In order for economically viable distributed generation systems for local community to spread, it is essential to develop an efficient and low-cost heat supply system. We propose a new heat supply system called DREAMS (Distributed Residential Energy with Advanced Management System). The key technology for the system is to connect compact heat supply units installed in all the households of the local community, such as a condominium, by a single loop of hot water piping. Two methods to decrease the heat supply rate through the single loop are proposed in this paper. The one is an utilization of a compact heat supply unit with heat storage in each house. The momentary heat demand can be covered by the heat storage. The other is a tap water preheating. A new CO2 regenerative heat pump cycle was proposed for the recover of the low temperature heat from the generator. A new heat supply unit with a practical capacity was manufactured, and the heat supply performance was evaluated by some experiments. Furthermore, an advanced energy management system has been under consideration to realize the effective system operation by utilizing IT. In this paper, experimental results on the performance of the new heat supply unit, the new CO2 heat pump system and evaluation of the energy-saving effect of our DREAMS are presented.

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RANGE OF EXHAUST GASES PRE-COOLING IN THE IMPROVED HEAT PUMP SYSTEM OF HEAT SUPPLY

Bulletin of Odessa State Academy of Civil Engennering and Architecture ◽

10.31650/2415-377x-2021-83-139-147 ◽

2021 ◽

pp. 139-147

Author(s):

V.D. Petrash ◽

◽

Yu.N. Polunin ◽

N.V. Danichenko ◽

◽

...

Keyword(s):

Energy Efficiency ◽

Heat Pump ◽

Heat Supply ◽

Initial Temperature ◽

Heat Supply System ◽

Supply System ◽

Hot Water ◽

Exhaust Gases ◽

Energy Flows ◽

Rotary Kilns

The paper studies the range of possible and rational pre-cooling of exhaust gases in an improved heat pump of heating supply system in the development of its previously proposed basic version. The research has established analytical dependences for determining the energy flows of the condenser and evaporator, as well as the energy efficiency of the improved heat supply system. On their basis, a rational range of preliminary cooling of exhaust gases of rotary kilns was revealed, the upper level of which is determined, first of all, by their initial temperature. It has been established that the rational ratio of water consumption for heating systems with traditional temperature drops and hot water supply is in the range of 0.3-0.9. At the same time, an increase in energy efficiency is noted in the process of operational regulation of systems with a decrease in the ratio of the costs of heat carriers for technological and household purposes. The degree of precooling of exhaust gases, which significantly depends on their initial temperature, is in the range of 0.35-0.5 with a decrease in the corresponding flow rates of heat carriers in heating and hot water supply systems. The rational ratio of the consumption of the heating and heated medium in the process of contact interaction, which significantly depends on the initial temperature of the exhaust gases, is in the range of 0.2-1.2. For low-temperature waste gases (up to 500С), the reciprocal values of the analyzed ratio logically agree with the corresponding values of the irrigation coefficient. The results of the analytical study established multifactorial dependences of energy flows in the condenser and evaporator, as well as determining the energy efficiency of an improved heat pump of the heat supply system, on the basis of which the general range of possible pre-cooling of exhaust gases from rotary kilns was revealed.

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ENERGY EFFICIENCY OF COMBINED HEAT SUPPLY SYSTEMS

Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) ◽

10.31319/2519-2884.39.2021.11 ◽

2021 ◽

Vol 2 (39) ◽

pp. 92-97

Author(s):

R. Klimov ◽

A. Morozovskaya

Keyword(s):

Water Supply ◽

Heat Supply ◽

Fossil Fuel ◽

Heat Supply System ◽

Heat Pumps ◽

Supply System ◽

Hot Water ◽

Solar Collectors ◽

Hot Water Supply ◽

Supply Systems

The consumption of energy resources in the world states is constantly growing from year to year. The production of fossil fuels is also increasing, but for various reasons it cannot fully cover the required amount from consumers. One of the most important consumption sectors is heat loads from heating, ventilation and hot water supply of industrial and residential buildings. To cover the thermal loads of heating and hot water supply, the necessary heat carrier is water heated to a certain temperature. The most promising from the point of view of heating water for hot water supply are solar collectors. Hot water for heating needs to be reheated practically throughout the entire heating period. The introduction of heat pumps is promising. When using solar collectors, the heating agent can be reheated in heat pumps. The aim of the study is to develop such a combined heat supply system that uses more renewable energy and as a peak source a fossil fuel boiler (electric energy), as well as a method for calculating this system to determine the optimal composition of equipment and rational modes of its operation. The methodology for calculating heat supply systems combining solar collectors, heat pumps and fossil fuel boilers is presented. The problem of load distribution between the main elements of the combined heat supply system should take into account the probabilistic component. This is due to the fact that with a changing real mode of operation, different thermal load of the equipment can be optimal. This is primarily influenced by the variable heat inputs from solar collectors during the day. According to the above method, it is possible to determine the optimal parameters of the heat supply system for different operating modes, at which the minimum consumption of fossil fuel will be ensured.

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ENERGY-SAVING HEAT PUMP TECHNOLOGY FOR HEAT SUPPLY SYSTEM OF HOUSING AND COMMUNAL SERVICES AND INDUSTRY According to the materials of scientific report at the meeting of the Presidium of NAS of Ukraine May 13, 2015

Visnik Nacional noi academii nauk Ukrai ni ◽

10.15407/visn2015.07.023 ◽

2015 ◽

pp. 23-31

Author(s):

Yu. F. Snezhkin ◽

Keyword(s):

Energy Saving ◽

Heat Pump ◽

Heat Supply ◽

Heat Supply System ◽

Supply System ◽

Scientific Report

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Efficiency of systems of heat supply with introduction of automated individual heating substations

E3S Web of Conferences ◽

10.1051/e3sconf/201912401026 ◽

2019 ◽

Vol 124 ◽

pp. 01026

Author(s):

Yu. N. Zvonareva ◽

Sh. G. Ziganshin ◽

E. V. Izmaylova ◽

A. S. Gavrilov ◽

A. V. Moryashev ◽

...

Keyword(s):

Performance Indicators ◽

System Performance ◽

Heat Supply ◽

Heat Supply System ◽

Supply System ◽

Research Results ◽

Heat Supply Systems ◽

Supply Systems

Article is devoted to increasing efficiency of heat supply systems. We demonstrate research results and an analysis of dependences of overall heat supply system performance indicators at various levels of equipment of consumers with the automated individual heating substations.

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INVESTIGATION OF VARIABLE MODES OF CENTRALIZED HEAT SUPPLY SYSTEMS OPERATION WITH QUALITATIVE AND QUANTITATIVE REGULATION

Construction and Geotechnics ◽

10.15593/2224-9826/2019.2.07 ◽

2019 ◽

Vol 10 (2) ◽

pp. 79-91

Author(s):

T. A Rafalskaya ◽

A. R Mansurov ◽

A. R Mansurova

Keyword(s):

Water Supply ◽

Flow Rate ◽

Heat Load ◽

Heat Supply ◽

Heat Supply System ◽

Hot Water ◽

Constant Flow Rate ◽

Network Water ◽

Qualitative And Quantitative ◽

Hot Water Supply

The combined method of generating electric and heat energy at CHP plants has been and remains the most effective way of fuel saving both in housing and communal services and in industry. In Russia, historically, a qualitative method of regulation has been adopted, which consists in changing the temperature of the fluid depending on the change in the temperature of the outside air at a constant flow rate of the fluid. An analysis of the heat supply schemes of a number of Russian cities revealed that central quality regulation at heat sources has practically ceased everywhere. In modern methods of calculating the qualitative and quantitative regulation, the main load is heating, and the load of hot water is taken into account only by increasing the flow rate of network water and the variable modes of joint operation of heating and hot water systems are not calculated. Thus, at present, there are no methods for calculating the qualitative and quantitative regulation, allowing to fully taking into account the effect of the load of hot water on the operation of heating systems. Therefore, in modern conditions, the previously developed methods and technological methods of controlling the combined heat load are characterized by a decrease in efficiency, and, accordingly, the problem of their optimization arises. For different temperatures of outdoor air, the calculation of variable operating modes of the heat supply system was carried out, which showed that the existing schedules of qualitative and quantitative regulation cannot provide a comfortable temperature condition of the premises. Under the conditions of a connected supply of heat, simply adding up the flows of network water for heating and hot water supply fails to achieve optimal thermal conditions for the premises. Therefore, further improvement of the technology of the central qualitative and quantitative regulation of the heat load taking into account hot water supply is required.

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Study of the Total Heat Supply System Using CO2-Heat Pump : Part 3 Effect of the Division of Gas Cooler (1)

Proceedings of thermal engineering conference ◽

10.1299/jsmeptec.2002.0_347 ◽

2002 ◽

Vol 2002 (0) ◽

pp. 347-348

Author(s):

Masaharu KATO ◽

Takuro SAKAMAKI ◽

Takumi HASHIZUME ◽

Hirokazu YONEDA ◽

Katsumi FUJIMA ◽

...

Keyword(s):

Heat Pump ◽

Heat Supply ◽

Heat Supply System ◽

Supply System ◽

Total Heat

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TWO-STAGE HEAT PUMPS FOR ENERGY SAVING TECHNOLOGIES

Refrigeration Engineering and Technology ◽

10.15673/ret.v53i1.539 ◽

2017 ◽

Vol 53 (1) ◽

Author(s):

A. E. Denysova ◽

G. V. Luzhanska ◽

I. O. Bodnar ◽

A. S. Denysova

Keyword(s):

Energy Saving ◽

Heat Pump ◽

Heat Supply ◽

High Efficiency ◽

Heat Supply System ◽

Heat Pumps ◽

Supply System ◽

Alternative Methods ◽

Ground Waters ◽

Two Stages

The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources have essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two stages heat pump installation operating as heat source at ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of groundwater energy. Calculated are the values of electric energy consumption by the compressors’ drive, and the heat supply system transformation coefficient µ for a low-potential source of heat from ground waters allowing to estimate high efficiency of two stages heat pump installations.

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