Auxiliary Heating Systems of Conventional and Heat Pump Type: Technology, Performance and Efficiency

Performance of combined solar-heat pump systems

Effect of heating system using a geothermal heat pump on the production performance and housing environment of broiler chickens

A solar-air source heat pump with thermosiphon to efficiently utilize solar energy

Fuzzy comprehensive evaluation of district heating systems

Water heating represents approximately 18% of residential energy consumption, or 4.6 quadrillion Btus of source energy use annually (EIA 2009). Heat pump water heaters (HPWHs) offer an efficient option for residential water heating, with the ability to reduce water heating energy consumption by up to 63%. Previous research has demonstrated the laboratory performance of HPWHs and has shown savings of 43 to 62% on water heating energy consumption are possible, based on field tests (Ecotope 2015). In order to achieve such high efficiencies, HPWHs employ a refrigeration cycle to move heat from the ambient air into the water. Therefore, when HPWHs are installed in conditioned space, they will remove heat from that space which can help the HVAC system in the cooling season and require additional energy from the HVAC system in the heating season. This project provides an unbiased evaluation of the space conditioning interactions between a HPWH and the heating system in several locations throughout the home to further our understanding of the impact that HPWHs have on space conditioning loads. This report explores the HPWH interaction factor from several perspectives: (1) a theoretical analysis, (2) a review of previous literature, and (2) an experimental assessment. The experiments were conducted in PNNL’s side-by-side Lab Homes, which provide a platform for evaluating energy-saving and grid-responsive technologies in a controlled environment. The PNNL Lab Homes are two factory-built homes installed on PNNL’s campus in Richland, Washington. The homes represent existing homes, which account for approximately 99% of occupied homes in the U.S. These 1500 ft2 homes have three bedrooms, two bathrooms, and are equipped with 7.7 HSPF heat pump and an electric forced air furnace. Both homes have R-22 floors, R-11 walls and R-22 ceiling insulation levels, with double-pane clear glass windows. The results of this experiment verified that the energy use of the HVAC system increases as a point source cooling load, like a HPWH, is moved closer to the thermostat. The opposite is also true, as a point source heating load is moved closer to the thermostat, the heating load decreases. The results show between 30-40% difference between the interaction that this type of load has when it is placed in the master bathroom compared to the living room for the PNNL Lab Homes.

Decarbonisation of domestic heating in the UK is expected to involve widespread replacement of gas boilers with heat pumps. This transition requires a reduction in heating system flow temperature for the heat pump to operate efficiently, which can necessitate costly radiator or fabric upgrades to provide sufficient heat. The requirements for existing dwelling and heating systems to have these upgrades therefore directly impacts the “heat pump readiness” of the UK stock. This paper applies a novel approach in using diagnostic data for approximately 4600 boilers to evaluate the viability of installing heat pumps with no changes made to the existing radiators or fabric. Results indicate that 31% of dwellings in the sample could operate with Low Temperature Heat Pumps (LTHPs) without upgrades to radiators or fabric, or up to two thirds with High Temperature Heat Pumps (HTHPs), whereas previous analysis using surveys has found that radiator upgrades are almost always needed. Therefore, the costs and disruption of heat pump roll out could be substantially lower than previously predicted, and the use of real heating system performance data could supplement survey-based assessments of heat pump readiness to help identify more accurately where upgrades are needed. Practical application Current design practices almost always lead to replacement of existing radiators when switching a gas boiler for a heat pump. However, analysis of diagnostic data from approximately 4600 boilers in the UK suggests this may not be entirely necessary. This measured heating system data indicates that up to two-thirds of UK dwellings could operate with High Temperature Heat Pumps (HTHPs) without upgrading existing radiators. Henceforth, development of data-driven testing procedures for the design of future heating systems has significant potential to facilitate rapid heat pump deployment at a national scale, a crucial step in decarbonising buildings in the UK.

The CO2 heat pump air conditioning system of new energy vehicle is designed, and the vehicle model of CO2 heat pump module and heat management system is established based on KULI simulation. The effects of refrigerant charge, running time and compressor speed on the heat pump air conditioning system is studied, and the energy consumption is compared with the PTC heating system and the CO2 heat pump air conditioning system without waste heat recovery. The results show that the optimal charge for full-service operation is 750 g; increasing the compressor speed can increase the cooling capacity, so that the refrigerant temperature in the passenger compartment and battery inlet can quickly reach the appropriate temperature, but the COPh, COPc are reduced by 2.5% and 1.8% respectively. By comparing it with PTC heating and CO2 heat pump air conditioning systems without waste heat recovery, it is found that the energy consumption of this system is only for the PTC heating systems 42.5%, without waste heat recovery carbon dioxide heat pump air conditioning system of 86.6%. It greatly saves energy, but also increased the waste heat recovery function, so that the system supply air temperature increased by 26%, improve passenger cabin comfort. This provides a reference for the future experimental research of CO2 heat pump air conditioning and heat management system.

Performance analysis of a novel dual heat source warm air heating system with ecofriendly refrigerants

Feasibility Analysis of Building Heating System Based on Thermal-Economical Evaluation

Performance analysis on compression-assisted absorption heat transformer: A new low-temperature heating system with higher heating capacity under lower ambient temperature

Solar absorption cooling has been an intriguing research subject since 1970. However, it is not widely applied because the first cost of the system is high, the commercial hot water absorption chiller is not mature, the site demonstration and evaluation are not adequate and the price of conventional fossil energy sources is relatively low. This paper investigates the commercialization potentials of solar absorption cooling and solar heating system by comparing the life cycle cost between it and the conventional electrical chiller cooling and gas-fired boiler heating system. A computational model has been programmed in the Engineering Equation Solver (EES) to analyze the economical performances of the two systems applied to a dedicated building. The model considers the cost of capital, installation, operation and maintenance, the discount rate, the fuel prices, and the inflation rates. The result of the model indicated that given the present fuel cost, the solar absorption cooling and heating system is not as economic as the conventional system especially when its size is small. However, according to the sensitivity analysis carried, the solar absorption cooling and heating system could compete with the conventional cooling and heating system when the electricity price and fuel inflation increase.

Thermal performance analysis of a new refrigerant-heated radiator coupled with air-source heat pump heating system

A significant part of energy in Norway is utilized for space heating due to the cold climate and heat pump technology has gained popularity in the country for space heating. According to the European heat pump association, Norway has the most heat pumps per capita in Europe, providing 16 TWh of heat energy annually. This review paper discusses the most common types of heat pumps in Norway. A comparison between the performance and payback time of different types of heat pumps in Norway is presented. Ground source heat pumps are more suitable than air source heat pumps due to maintaining a higher coefficient of performance during cold periods. The amount of thermal energy extracted using ground source heat pump systems is estimated to be 3 TWh and expected to be 8 TWh by 2030. However, more than 90% of heat pump installations in Norway are air source heat pumps. Compared to air source heat pumps, ground source heat pumps face many challenges, such as high initial cost, lack of public awareness, and insufficient professional workforce. The sales of heat pumps dropped by 13% in 2020, mainly due to the Covid-19 impact on the market. However, the sales increased significantly in 2021 due to the ongoing energy crisis and increase in energy prices.

Field research on the trinity energy storage and heating system of villa in cold area

Objectives. Determination of the effectiveness of using various types of heat pumps in the extractive distillation of an isobutyl alcohol–isobutyl acetate mixture with n-butyl propionate as the entrainer.Methods. As the main research method, mathematical modeling was performed using the Aspen Plus V. 9 software package. As a model for describing the vapor–liquid equilibrium, the local composition equation-based UNIQUAC model was employed, and the Redlich–Kwong model was adopted to examine the non-ideal vapor phase. When modeling the conventional scheme of extractive distillation, parametric optimization was carried out according to the criterion of total energy costs in the reboilers of the columns. For economical evaluation, Aspen Process Economic Analyzer V10.1 tools were employed. Results. In comparison with the conventional extractive distillation scheme, three variants of schemes with vapor-recompression heat pumps were considered: with a heat pump placed on an extractive distillation column, on an extractive agent regeneration column, and with two heat pumps placed on both columns of the scheme. A scheme with an internal heat pump was also proposed, in which the heat pump compressor is located between sections of extractive columns that operate at different pressures: 506.6 kPa in the top sections and 101.3 in the bottom section. An economic analysis was conducted for all the considered schemes to calculate the total annual costs. It was shown that schemes with vapor-recompression heat pumps can significantly reduce the energy costs of extractive distillation by up to 39.6%; however, a significant reduction in the total annual costs is achieved only with sufficiently long operation periods of the plants. The reduction in the energy costs in the scheme with an internal heat pump was 44%, and the total annual costs were in the range of 20.2–30.1%, depending on the operating time of the plant. Conclusions. It was shown that using heat pumps in the extractive distillation of the mixture of isobutyl alcohol–isobutyl acetate with n-butyl propionate as the entrainer can significantly reduce energy costs. The scheme with an internal heat pump is the most economical of all the considered schemes.