Determination of the influence of the SpeedComfort fan system affixed on a plate radiator.

Transcription

1 TNO report TNO 2016 R11745 Determination of the influence of the SpeedComfort fan system affixed on a plate radiator. Technical Sciences Leeghwaterstraat CA Delft P.O. Box JA Delft The Netherlands T F Date 16 December 2016 Author(s) H.A.J. Hammink Copy no No. of copies Number of pages Number of appendices Sponsor 18 (incl. appendices) SpeedComfort Hertenlaan 31B 3734 CE Den Dolder The Netherlands Project name Project number All rights reserved. No part of this publication may be reproduced and/or published by print, photoprint, microfilm or any other means without the previous written consent of TNO. In case this report was drafted on instructions, the rights and obligations of contracting parties are subject to either the General Terms and Conditions for commissions to TNO, or the relevant agreement concluded between the contracting parties. Submitting the report for inspection to parties who have a direct interest is permitted TNO

2 TNO report TNO 2016 R / 18 Summary For SpeedComfort, firm located in Den Dolder The Netherlands, TNO has determined the influence of the SpeedComfort fan system on the heat transfer of a plate radiator. The situations with SpeedComfort are compared to the situation without SpeedComfort. The SpeedComfort system consists of several fans which can be mounted on a 2 plated radiator. The fans are switched on depending of the radiator temperature. The forced ventilation is to improve the convective heat from the radiator. The test setup was installed in the TNO MEC laboratory in Delft. During the different measurements the water flow, water inlet temperature and the positions of the SpeedComfort fan system were changed. Also two setups for the water inlet and outlet connection were considered. For setup 1 the water inlet connection is on top and the outlet at the opposite bottom connection. For setup 2 the water inlet connection is on top and the outlet at the same side on the bottom. The influence of the SpeedComfort on the thermal output and the excess temperature are shown in the table underneath, for various water flow rates and the two water inlet and outlet setups. Setup Water flow [l/h] Increase thermal output [W] Increase thermal output [%] Reduction excess temperature [%] During all the measurements the SpeedComfort had a positive impact on the thermal output of the radiator.

3 TNO report TNO 2016 R / 18 Contents 1 Introduction Description of the appliance SpeedComfort module Plate radiator Test setup Test results Principles used Results Summary of the test results and conclusions Signature... 18

4 TNO report TNO 2016 R / 18 1 Introduction SpeedComfort, firm located in Den Dolder The Netherlands, has asked TNO to determine the influence of the SpeedComfort fan system on the heat transfer of a plate radiator. The situation with SpeedComfort is to be compared to the situation without SpeedComfort. The SpeedComfort system consists of several fans which can be mounted on a 2 plated radiator. The fans are switched on depending of the radiator temperature. The forced ventilation is to improve the convective heat from the radiator. The SpeedComfort system focuses on existing situations where, due to the increased heat transfer, the radiator can provide the same heating capacity at lower water return temperatures. Energy saving is then possible by: a) more condensation in the boiler. b) less pipe losses. It is further indicated that this system has the advantage to have an accelerated heating due to the higher capacity. The aim of the study is to determine the influence of the fans on the heat output of the radiator. A description of the SpeedComfort fan system can be found in Chapter 2. The tests proposed can be performed in the TNO MEC laboratory in Delft, were ambient temperature can be controlled and water flow, water inlet temperature and the positions of the SpeedComfort can be changed. The test setup is described in Chapter 3. The test results can be found in Chapter 4, and are summarised in Chapter 5, in which also conclusions can be found.

5 TNO report TNO 2016 R / 18 2 Description of the appliance 2.1 SpeedComfort module The SpeedComfort system consists of several fans which can be mounted on a 2 plated radiator. The fans are switched on and off depending of the radiator temperature. The forced ventilation is to improve the convective heat transfer from the radiator. Manufacturer: SpeedComfort Hertenlaan 31B 3734 CE Den Dolder The Netherlands Telephone: +31 (0) Start date of testing: October 2016 Type: SpeedComfort B(asic) Year of construction: 2016 CE approval: Yes Power consumption: 1.62 [W] 2.2 Plate radiator Manufacturer: Type: Size (hxw): Output: Imas 22 (ASSOT23-05) 500 x 1000 [mm] 1502 [W] (According EN442 T=50 [K])

6 TNO report TNO 2016 R / 18 3 Test setup The test setup was installed in the TNO MEC laboratory in Delft (L=30 [m], W10 [m] H=7 [m]. The ambient temperature was between 19 ± 2 C General The measured values are recorded using a data acquisition system that reads the values at fixed intervals (reading and saving all data at the same time). The measured values for the incoming water flows are checked for a variation in time in order to restrict the spread to a minimum. A stable period is a period when the water control represents a repeating period. The total duration of the measurements depends on the stability of the measurement process. Depending on the water temperature, the duration of the period is 10 to 30 minutes. In order to declare a measurement valid at least four consecutive measurement periods must comply with the stability criteria as given in Criteria for the stability of the measurement process maximum variation of average air inlet temperature reading: 0.2 K; maximum variation of water flow 3 l/h; maximum variation of water inlet temperature: 2 K Setup The influence of the SpeedComfort fan system is determined for 2 water flow connections. Setup 1: the water inlet connection is on top and the outlet at the opposite bottom connection. Setup 2: the water inlet connection is on top and the outlet at the same side on the bottom. At the air inlet of the radiator 7 thermocouples are installed, at 2cm from the inlet, see figure 1. The distance from the temperature sensors to the left side of the radiator are: 4, 20, 35, 53, 65, 80 and 96cm.

7 TNO report TNO 2016 R / 18 Figure 1 Temperature sensors positions at the air inlet side The air outlet temperature is measured under the grill at 5 different points, see figure 2. The distance from the sensors to the left side of the radiator is: 7, 25, 48, 68 and 92 cm. Figure 2 Temperature sensors positions at the air outlet side The thermal output of the radiator is calculated, water sided, as: ɸ = cp qm water (Twater inlet Twater outlet ) in which: Thermal output ɸ [W] Specific heat cp Water mass flow qmwater [kg/s] Water inlet temperature Twater_inlet [ C] Water outlet temperature Twater_outlet [ C] The excess temperature is calculated: T = (Twater_inlet+Twater_outlet ) 2 Tair_inlet_avg in which: Excess temperature T [K] Average air inlet temperature Tair_inlet_avg [ C] The reduction of the excess temperature is calculated: Treduction = Twithout SpeedComfort Twith Speedcomfort

8 TNO report TNO 2016 R / 18 The applied measuring sensors are listed in Table 1. Table 1 Measuring sensors Measuring Channel TUI Number Identification qv-water 1011 A56 T-water-inlet 1015 A57 T-water-outlet 1021 R01 Tair-in R03 Tair-in R04 Tair-in R05 Tair-in R07 Tair-in R09 Tair-in R10 Tair-in R24 Tair-out R27 Tair-out R28 Tair-out R29 Tair-out R30 Tair-out5 Power meter

9 TNO report TNO 2016 R / 18 4 Test results 4.1 Principles used The influence of the SpeedComfort system was determined under the test conditions as shown in Table 2. The air inlet temperature was between 19 ± 2 C (ambient temperature). Table 2 Test conditions Measurement no. Water flow Water inlet temperature MX [l/h] [ C] 1, 7, 8, 9, , 62, 50, 44, 30 5, 15, 14, 12, , 49, 46, 36 2, 11, , 42.5, 29 14, 13, 16, 17, , 49, 47, 44, 32 In the tables in section 4.2 the,, and behind the measuring numbers MX gives the place of the SpeedComfort system. See Table 3. Table 3 Position SpeedComfort MX MX' MX'' MX''' MX'''' without SpeedComfort with SpeedComfort below radiator with SpeedComfort above radiator with SpeedComfort between outlet grill and the radiator with SpeedComfort below radiator without outlet grill The variables that were used are shown in Table 4. Table 4 Used variables Parameter Unit Electric power SpeedComfort Pel_SpeedComfort [W] Water volumetric flow qv_water [l/h] Water mass flow qm_water [kg/s] Water inlet temperature Twater_inlet [ C] Water outlet temperature Twater_outlet [ C] Water temperature drop dt_water [K] Average air inlet temperature Tair_inlet_avg [ C] Average air outlet temperature Tair_outlet_avg [ C] Average air temperature increase dtair_avg [K] Thermal output ɸ [W] Thermal output change between without and with SpeedComfort ɸc [%] Excess temperature T [K] Reduction of Excess temperature Treduction [K]

10 TNO report TNO 2016 R / Results The results of the measurements are shown in tables 5 to 8. The figures 3, 5, 7 and 9 give the results of the excess temperature compared to the heat output. The figures 4, 6, 8 and 10 give the comparison between the heat output and the excess temperature. In order to clarify the improvement of the SpeedComfort system the excess temperature difference is also displayed as a percentage Setup 1 Table 5 Results of the measurements at a water flow of 85 [l/h] M1 M1' M7 M7' M7'' M8 M8' M8'' M10 M10' M10'' M9 M9' M9'' Pel_speedcomfort [W] qv_water [l/h] qm_water [kg/s] Twater_inlet [ C] Twater_outlet [ C] dt_water [K] Tair_inlet_avg [ C] Tair_outlet_avg [ C] dtair_avg [K] ɸ [W] ɸc [%] T [K] Figure 3 Impact SpeedComfort at qv_water 85 [l/h]

11 TNO report TNO 2016 R / 18 Figure 4 Temperature reduction at qv_water 85 [l/h]

12 TNO report TNO 2016 R / 18 Table 6 Results of the measurements at a water flow of 134 [l/h] M5 M5' M15 M15' M15'' M14 M14' M12 M12' M13 M13' Pel_speedcomfort [W] qv_water [l/h] qm_water [kg/s] Twater_inlet [ C] Twater_outlet [ C] dt_water [K] Tair_inlet_avg [ C] Tair_outlet_avg [ C] dtair_avg [K] ɸ [W] ɸc [%] T [K] Figure 5 Impact SpeedComfort at qv_water 134 [l/h] Figure 6 Temperature reduction at qv_water 134 [l/h]

13 TNO report TNO 2016 R / 18 Table 7 Results of the measurements at a water flow of 175 [l/h] M2 M2' M11 M11' M11'' M12 M12' Pel_speedcomfort [W] qv_water [l/h] qm_water [kg/s] Twater_inlet [ C] Twater_outlet [ C] dt_water [K] Tair_inlet_avg [ C] Tair_outlet_avg [ C] dtair_avg [K] ɸ [W] ɸc [%] T [K] Figure 7 Impact SpeedComfort at qv_water 175 [l/h] Figure 8 Temperature reduction at qv_water 175 [l/h]

14 TNO report TNO 2016 R / Setup 2 Table 8 Results of the measurements at a water flow of 134 [l/h] M14 M14' M14'' M14''' M13' M16''' M17 M17' M16 M16' M15' M15'' M15''' M16'''' Pel_speedcomfort [W] qv_water [l/h] qm_water [kg/s] Twater_inlet [ C] Twater_outlet [ C] dt_water [K] Tair_inlet_avg [ C] Tair_outlet_avg [ C] dtair_avg [K] ɸ [W] ɸc [%] T [K] Figure 9 Impact SpeedComfort at qv_water 134 [l/h] Figure 10 Temperature reduction at qv_water 134 [l/h]

15 TNO report TNO 2016 R / 18 5 Summary of the test results and conclusions Figures 11 and 13 show the difference between the thermal output without SpeedComfort and with SpeedComfort placed below the radiator and figures 12 and 14 show the difference of the excess temperature. Figure 11 Impact SpeedComfort on the thermal output Figure 12 Impact SpeedComfort on the excess temperature

16 TNO report TNO 2016 R / 18 Setup 1 - At a water flow of 85 [l/h] the reduction of the excess temperature is 8-16 [%] over a range from [W].The thermal output increased between 8 and 21 [%] - At a water flow of 134 [l/h] the reduction of the excess temperature is [%] over a range from [W]. The thermal output increased between 15.5 and 24 [%] - At a water flow of 175 [l/h] the reduction of the excess temperature is 9-16 [%] over a range from [W]. The thermal output increased between 11 and 27 [%] - During all the measurements the SpeedComfort has a positive impact on the thermal output of the radiator. - The SpeedComfort system installed above the radiator has less influence on the heat transfer than the SpeedComfort installed below the radiator. Setup 2 - At a water flow of 134 [l/h] the reduction of the excess temperature is 9-21 [%] over a range from [W]. The thermal output increased between 8 and 31 [%] - The SpeedComfort system installed above the radiator has less influence on the heat transfer than the SpeedComfort installed below the radiator. - SpeedComfort installed between the outlet grill and the radiator gives a small improvement compared with the SpeedComfort installed above the radiator. - Measuring point M16 with SpeedComfort and without outlet grill gives no significant difference on the heat output compared with SpeedComfort and with outlet grill M16.

17 TNO report TNO 2016 R / 18 Comparison between Setup 1 and 2 - The influence of the SpeedComfort system on the thermal output is larger in Setup 2. - The influence of the SpeedComfort system on the excess temperature is larger in Setup 2 above 350 [W]. Figure 13 Impact SpeedComfort on the thermal output at 134 [l/h] Figure 14 Impact SpeedComfort on the excess temperature at 134 [l/h]

18 TNO report TNO 2016 R / 18 6 Signature Delft, 16 December 2016 H.A.J. Hammink Author H. Polinder Reviewer Frank Driessen Research manager ad int. Heat transfer and fluid dynamics