Heating and cooling systems in buildings. Method for calculation of the system performance and system design for heat pump systems

2014 ◽  
Author(s):  
Giovanni Nurzia ◽  
Giuseppe Franchini ◽  
Antonio Perdichizzi

The deployment of solar driven air conditioning is a feasible target in all countries where high solar irradiation matches high cooling loads in buildings: the goal is to gradually replace compression chillers and reduce peak electricity demand during summer. Moreover, as solar thermal collectors are installed, solar cooling systems can be profitably employed during winter. In the present work a code has been implemented for the simulation and the design optimization of combined solar heating and cooling systems. The following system layout has been considered: in warm months the cooling demand is satisfied by means of an absorption chiller — driven by a solar collector field — and a reversible heat pump operating in series. A hot storage matches the variability of solar radiation, while a cold storage smoothes the non-stationarity of cooling demand. During winter, the reversible compression heat pump operates for space heating. Solar collectors are used as thermal source at the evaporator of the heat pump, increasing its coefficient of performance. The code, based on TRNSYS platform, is able to simulate the system throughout a year. Besides TRNSYS standard components a detailed model of the absorption chiller has been included, in order to accurately simulate its off-design operation. Using an optimization tool the size of each component is identified for a given space heating and cooling demand. The minimization of life cycle costs of the system has been chosen as the objective of the optimization. Results of a case study are presented and discussed for a solar heating and cooling plant in an office building. The optimization procedure has been carried out with simulations for a typical Northern Italy town (Alpine climate) and a typical Southern Italy town (Mediterranean climate).


2019 ◽  
Vol 111 ◽  
pp. 01076 ◽  
Author(s):  
Mingzhe Liu ◽  
Ryozo Ooka ◽  
Toshiyuki Hino ◽  
Ke Wen ◽  
Wonjun Choi ◽  
...  

We herein report the development of a distributed heat pump system that can utilize a variety of renewable energy sources to meet different building heating and cooling demands (i.e., a multiple source and multiple use heat pump system, MMHP). In this system, a water circulating loop is used to connect ground heat exchangers, a unique sky-source heat pump, and various heat pumps for heating and cooling purposes to form a thermal network within a building. This distribution increases the flexibility of the system and allows an improved matching of supply and demand. To evaluate the system performance, an experimental house was constructed, and a winter field experiment was conducted. We found that the reported heat pump for floor heating achieved a stable operation with a high coefficient of performance of ~11.5, while the heat collecting operation performance of the sky-source heat pump varied significantly depending on the amount of solar radiation and the outside air temperature. Finally, since the sky-source heat pump contributes to an improvement in the whole system performance, it appears that there is still room for improved regarding the whole system performance by adjusting the operating and control strategy.


2016 ◽  
Vol 77 ◽  
pp. 06008
Author(s):  
G.P. Vasilyev ◽  
V.F. Gornov ◽  
M.V. Kolesova ◽  
A.N. Dmitriev ◽  
V.G. Silaeva

2006 ◽  
Vol 12 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Per Fahlén ◽  
Hendrik Voll ◽  
Jüri Naumov

Developments in pump technology provide new possibilities of improving both the efficiency and the quality of control of hydronic heating and cooling systems. Improved pump efficiency and direct flow control can substantially reduce the drive power to circulation pumps. Measurements show that a simple VSD (variable speed drive) does not unduly degrade the efficiency of commonly used pumps. An example from a residential heat pump installation indicates possible savings of around 30 % of the total drive energy to the heat pump. Another example illustrates how direct flow control can simplify systems and reduce electric drive power in supply‐air conditioning systems.


Sign in / Sign up

Export Citation Format

Share Document