【 Weak current College 】 on standard change on fan-coil---Power By 【 China power house network 】

Summary: the fan coil unit "national standard GB/T19232-2003 is December 1 2003 formally implemented. National standards and has discontinued JB/T4283-91 there are a lot of changes, including on the high static pressure unit performance parameters detailed regulations. Especially for dark machine group performance test conditions expressly provided for. On without filters and air outlet pressure of unit should be in the State of the test, 12Pa and original standards require zero static testing results to have some differences. This article by different models of fan coil unit respectively export zero static pressure and the air flow 12Pa State, power values measured and compared to the reference to improve, but also for high static pressure unit in structure matching problems on.
Keywords: external static pressure testing machine condition rating

National standards GB/T19232-2003 the fan coil unit on 1 July 2003, 1 December 2003 onwards. National air conditioning equipment quality supervision and inspection center on fan coil unit testing has begun to use national standard methods of test, and unit of performance indicators is also provided in accordance with the national standard for judging the rating.

National standards and has discontinued JB/T4283-91 of the fan coil unit of comparison, from model specifications, terms and specifications, installation, etc., all have a number of new provisions. On dark machine group test requirements change some more, and dark machine groups in application and broader, this article focuses on dark machine groups in some of the issues in testing.

1. terms and definitions

1.1 standards according to export static pressure will fan coil unit clearly points out the low static pressure and high static pressure. High static pressure unit is a unit in a outlet pressure of not less than the unit 30Pa. Low static pressure unit clearly without filters and diffusers when exporting static pressure for 12Pa. export static pressure means overcoming itself when rated air flow resistance in the outlet pressure, Pa.

1.2 rating refers to the standard requirements of test conditions, the unit should meet basic value, i.e. the product nameplate and the value of the product sample annotations. The past performance of the unit is based on the standard provisions found in the nominal value, on the nameplate values and sample values do not determine the value of the unit's nameplate and sample values are generally better than nominal value, or even better, this gives design units and user selection only based on the sample values, generate deviation; GB/T19232 standard in value when the nameplate or sample values over standard regulation value, determined by the value for the nameplate, which control the product quality, avoid certain corporate propaganda, it is exaggerated production enterprises in the preparation of the samples and product nameplate should pay attention.

2. test method

In the past, as in the original standard 2.1 detects horizontal dark machine group, general export static pressure is at zero pressure state detection, detection of dark machine groups are without diffusers and filter, so it should be under pressure in a outlet 12Pa. National standards have been added to the export request isostatic pressing unit of the relevant parameter is in line with market requirements.

2.2 for static pressure requirements of unit testing, testing of high, medium, low stalls of parameters, it is first necessary to determine the unit value of the static pressure in third gear export, it is recommended that you use either of the following methods:

(1) high, medium, low airflow ratio or air flow in third gear calculation

P=（L/L）P，P=（L/L）P

P=LP，P=LP

Type: P, P, P — — high, medium, and low stalls of export static pressure, Pa;

L, L, L-high, medium, low airflow, third gear unit m/h;

L, L-medium and low proportion.

For example: when a high, medium, low airflow in accordance with the standard recommended third gear ratio 1: 0.75: 0.5, unit export static pressure respectively 12Pa, 6.75Pa, 3Pa; such as the third gear ratio of 1: 0.8: 0.6, unit export static pressure respectively 12Pa, 7.68Pa, 4.32Pa.

(2) press the noise test method for high, medium, low stalls when ventilation rate of export static values.

3. horizontal dark machine groups according to the standard provisions of the export impact of the hydrostatic testing

We have two different production enterprise model coil to be detected, the horizontal dark machine group press export static 0Pa and GB required when test results are 12Pa, units of the air flow in a outlet pressure reduction than 0Pa 12Pa 6% to 11%, while the power reduction of 2% to 4%, see table <1>、表<2>, this explains why unit installed on the project after the air flow is one of the reasons for the production of enterprise is very worthwhile.

Table of comparative data unit 1FP-6.3

Project unit number

Export static 1234567

Air volume

（m/n）0Pa756816939809780760873

12Pa672737873733696713793

Difference 84796676844780

Power (W) 0Pa66635252627053

12Pa64625150606852

Difference 2112221

Table of comparative data unit 2FP-10

Project unit number

Export static 123456

Air volume

（m/n）0Pa12131194118610411178975

12Pa1136110110799491086913

Difference 7790107929262

Power (W) 0Pa10610291959383

12Pa1039989919080

Difference 332433

4. the restrictions in respect of the hydrostatic units noise measurement methods and installation requirements

When you need to press the 4.1 beta standard requirements in the inlet connection experiment air pipe, adjust the desired machine external static pressure (see Figure 1).

4.2 Hemi-anechoic chamber for testing, measuring and dots in the reflection surface (ground) to greater than 1 m;

4.3 unit and connections should be tight air leakage-free pipe segments to ensure accurate detection of static pressure value.

Figure 1 the export pressure unit noise measurement

5. in accordance with the requirements of GB/T19232 unit in testing frequently encountered problems

5.1 no past standard on unit stalls of air flow ratio, and the static pressure required in GB unit must be clear of the static pressure air flow in third gear. Enterprises in motor selection, a third gear ratio between the air flow is not adjusted well, some units even third gear air flow with almost no difference between the high and middle not opened or low is too small, these are not in compliance with the requirements of the users.

5.2 to meet in export volume of hydrostatic 12Pa requirements, power should be simple, though the amount of wind to reach targets, the cooling capacity is up to the rated value;

The unit for 5.3 so that cooling capacity up to but not on the cooling coil for improved air flow over standard values too much, resulting in noise value is greater than the standard value, the more common;

5.4 selection, poor motor in the detection of static pressure requirements, motor unit noise hummed;

5.5 unit selection of wind wheel size is too large or too small, and the static pressure requirements, in particular small wind turbine impeller selection should carefully;

5.6 on high static pressure unit, assembly bolts, plate, dish, table, water cooler copper pipe and siding connection air leakage problem, some units in the high static pressure, the air leakage rate of up to 20%, it is recommended that production enterprises in the Assembly, noting the sealed unit.