KQF Series Intelligent Storage Pump Station
The KQF series intelligent regulating and accumulating pump station is a new regulating and accumulating pump station product with fully prefabricated components, integrated supply in complete sets, and outdoor ground installation. The appearance of the KQF product consists of a cylindrical water tank and a steel structure pump house.The technical solution adopts a generalized laminated water supply solution with outlet parallel regulation and storage.
KQF Series Intelligent Storage Pump Station
Faced with the four basic problems of regulation and storage pumping stations, KQF regulation and storage pumping stations have obvious technical and economic advantages.
KQF pumping stations are particularly beneficial for water hygiene
A: It adopts stainless steel cylindrical water tank, which is clean, hygienic, easy to clean, easy to maintain and has no leakage. It is an upgraded product for regulating and storing pump stations to ensure water quality and hygiene.
Advantages of intelligent regulation and storage technology of KQF pump station
B: Using intelligent storage technology based on analysis, learning and prediction of flow, liquid level, and water inlet and outlet time-varying curves, the storage performance is better than traditional pool (water tank) storage, which can dispel doubts.It is safe to use superimposed water supply technology in regulating and storage pumping stations.
KQF Pump Station Reliability Design Advantages
C:KQF products are based on long-term experience in pump station products and engineering practice. They adopt a series of reliability designs to ensure uninterrupted water supply in case of failure. They also adopt a series of advanced technology integration to ensure continuous and reliable unattended operation (refer to KQF technical characteristics description)
KQF pumping station has obvious energy saving effect
D:On the one hand, more than 80% of the water supply of KQF is superimposed water supply, which can save 30-50% of energy compared with traditional transfer booster pump stations; on the other hand, the height of KQF supporting water tank is 6-10 meters.
The energy consumption of water supply used for regulating storage (transit boosting) has also been significantly reduced.
- Comparative advantages of KQF pumping station
- Comprehensive cost comparative advantage
- Model preparation
- KQF pump station implementation standards
- KQF Pump Station Principle and Equipment Composition
- Technical features of KQF products
- KQF products - layout drawing
In addition to the above basic advantages, in the current construction or reconstruction and expansion projects of various forms of intermediate pumping stations, the use of KQF regulating and storage pumping stations also has the following comparative advantages.
Compared with traditional underground pools and semi-underground civil pump rooms:
The KQF pumping station has fully prefabricated components, complete integrated supply, on-site assembly, and rapid construction; the KQF pumping station is higher than the ground, will not flood the pump room, has a gravity flow drainage ditch, and does not need to set up a drainage pump.
Compared with the regulating and storage pumping station using rectangular stainless steel water tank:
The KQF pumping station uses a cylindrical stainless steel water tank, which relies on its structural strength to ensure reliability (designed with reference to petrochemical storage tank standards) and has high reliability.
Alternative advantages of expansion and renovation:
It occupies a small area and requires very little civil construction, which is particularly conducive to simplifying complex civil construction approval matters. The construction is simple, the water supply can be quickly renovated and expanded, and a green belt landscape pumping station can be constructed.
In addition to the above performance advantages, the KQF pump station also has the advantages of rapid construction, no civil construction costs, doubled floor area, unattended operation, and low long-term energy-saving operation costs.
Advantages of KQF product grid application:
Grid zoning planning for urban water supply, with a standardized grid regulation and storage pumping station (grid pumping station) set up in each grid area, will produce a series of new beneficial changes.
- The intelligent regulation and storage function of the grid pump station ensures that the inlet flow rate is less than the outlet flow rate during peak periods, reducing the maximum flow burden on the upstream pipe network. It can be said that to a certain extent, it expands the water supply guarantee capability of the upstream pipe network during peak periods;
- The intelligent regulation and storage function of the grid pump station can support the downstream secondary water supply to generally adopt superimposed water supply without regulation and storage, forming a continuously sealed secondary pressurized water supply, which is especially beneficial to the hygiene and safety of the secondary water supply;
- The widespread application of grid pumping stations can effectively reduce the pressure of the upstream pipe network, reduce leakage, reduce water hammer hazards, etc.;
- As an important node in the pipeline network, the grid pump station has complete monitoring functions, which is especially beneficial to the DMA leakage control of the pipeline network;
- The uniformity of specifications of grid pumping stations is particularly conducive to the standardization of pumping station products and the maintenance and repair of pumping stations.
The KQF pump station model only provides the most basic feature information of the regulating and storage pump station. For more product information, please refer to the relevant instructions, technical specifications table, selection and ordering notes, etc.
There are currently no industry standards or national standards for regulating and accumulating pump stations. Its design and manufacturing comply with the enterprise standard Q31-0114000066C021-2020 “Intelligent regulating and accumulating pump station”.
The characteristics of the regulating and storage pumping station: it is both a complete set of integrated products and a small capital construction project. As a product, its function and performance can be seen as an improvement and expansion of secondary supply equipment, inheriting the advanced technology of secondary supply pump stations in recent years; as a project, it must also absorb the experience summary (relevant standards) of long-term water supply project design and construction.
For the formulation of product enterprise standards, the latest domestic standards and specifications were mainly referenced in two aspects:
GB50013-2019 “Outdoor Water Supply Design Standard”
GB50015-2019 “Design Standard for Building Water Supply and Drainage”
The design and construction of cylindrical water tanks refer to the following standards:
SH 3046-1992 “Design Specifications for Vertical Cylindrical Steel Welded Storage Tanks for Petrochemical Industry”
NB/T 47003.1-2022 “Atmospheric Pressure Vessels Part 1: Steel Welded Atmospheric Pressure Vessels”
KQF piping system principle:
As shown in the figure, when supplying water, the laminated water supply pump unit is first started. When the demand cannot be met or the peak period is adjusted, the transfer booster pump unit is started. The two units are connected in parallel to meet the water supply demand.Realize the regulation and storage compensation function (the water tank inlet valve automatically closes during the regulation and storage operation).
| Main equipment accessories name list | |
| Serial number | Name |
| 1 | Frequency conversion booster pump |
| 2 | Flexible rubber joint |
| 3 | Check valve |
| 4 | Service valve |
| 5 | Electromagnetic Flowmeter |
| 6 | Main water inlet valve |
| 7 | Flexible rubber joint |
| 8 | YUUITY filter |
| 9 | Backflow preventer |
| 10 | Electric main valve |
| 11 | Water tank inlet inspection valve |
| 12 | Water tank inlet electric valve |
| 13 | Water tank inlet remote control float valve |
| 14 | Water tank inlet electromagnetic flow meter |
| 15 | Water tank manhole |
| 16 | Water tank vent |
| 17 | Water tank overflow |
| 18 | Water tank drain pipe |
| 19 | Gutter |
| 20 | Water tank cleaning booster pump |
| 21 | Outlet main pipe |
| 22 | Pressure relief valve |
| 23 | Meter |
| 24 | Electromagnetic Flowmeter |
| 25 | Outlet main valve |
| 26 | Vent |
| 27 | No negative pressure steady flow tank |
| 28 | PLC |
| 29 | Electric control cabinet |
| 30 | Dual power cabinet |
| 31 | Water quality monitoring cabinet |
KQF consists of the following parts
A. Steel structure pump house: Prefabricated steel structure assembled on site, including interior and exterior decoration;
B. Backflow prevention facilities: including filters, backflow preventers, front and rear inspection valves, and supporting monitoring instruments (optional);
C. double unit water pump: including 2 sets of water pumps, supporting pipelines, pipe fittings, valves, etc.;
- Regulation and storage facilities: including water tanks (standard cylindrical water storage tanks), remote control float valves, electric control valves, liquid level and water inlet flow monitoring instruments, and all accessories inside and outside the water tank, connecting pipes, and maintenance valves;May also include cleaning facilities (optional);
E. variable frequency control cabinet: including on-site instruments, flow pressure sensors, full variable frequency drag control of water pumps, water tank storage (peak shaving) control, variable volume liquid level control (water age optimization control),May also include control of cleaning facilities (optional);
F. Water quality monitoring cabinet (optional): including multi-channel water sample sampling device, online monitoring instruments for turbidity, residual chlorine, Ph value, TDS (total solid solution) and other parameters,It can perform comparative monitoring of multi-dimensional, historical data and standard data on multi-channel water quality sampling parameters, and provide early warning and protection;
G. IoT security cabinet (optional): Wired or wireless remote monitoring based on the Internet of Things, including remote monitoring of pump station security information, environmental monitoring, water quality monitoring, equipment condition monitoring data, and remote monitoring of pump room video images.
Feature 1: Universal and flexible dual-mode technical solution
KQF regulating and storage pumping station plan: adopts a composite (dual-mode) water supply plan of pipe network overlay and transfer boosting, and among the common three types of dual-mode plans,
A parallel dual-mode solution was chosen: two sets of dual units with different boosting modes are connected in parallel, and the two water sources are naturally switched, without a series of problems caused by switching facilities. It has the best versatility and also has special flexibility.
(1) The versatility of the KQF solution: it can accommodate and adapt to various application scenarios (refer to the aforementioned application scenarios and advantage descriptions), and it also has good scalability and extended applications.The upward extension can be applied to a larger-scale intermediate pumping station, and the downward extension can be used as a secondary water supply pumping station.
(2) The flexibility of the KQF solution: It is especially reflected in the fact that it has a variety of pump configuration solutions, which can be optimized by the design institute.
| Pump configuration one (complementary dual mode) |
Pump configuration two (Main and complementary dual mode) |
Pump configuration three (Mutual backup dual mode) |
| Neither dual mode (two pumps) can meet the water supply demand independently, and the flow needs to be complementary. Features: low cost, high cost performance. |
Mainly based on a certain boosting mode, its pump can independently meet water supply needs. Features: Between (1) (3) |
Both boosting modes (2 pumps) can independently meet water supply needs. Features: 2 sets of pumps are mutually available and highly reliable. |
| KQF standard products are usually equipped with pumps in complementary dual mode by default, and are equipped with pumps according to the total flow n with 1 (for specific configuration methods, please refer to the following content) | ||
Feature 2 – Easy-to-clean cylindrical water tank without tie bars
Especially to solve the problems of existing rectangular water tanks, a stainless steel cylindrical water tank was designed and developed with reference to the petrochemical standard SH3046-92 “Design Specification for Vertical Cylindrical Steel Welded Storage Tanks”. Its overall structural strength, stiffness and stability are fully guaranteed. .
Compared with ordinary rectangular water tanks, the advantages are as follows:
(1) The force of the cylindrical water tank is balanced, and the failure mode is different from that of the rectangular water tank. Quality defects at local points are easy to repair, and there is no risk of collapse;
(2) Compared with rectangular water tanks, the ultra-high design (6-10m) saves about 2-3% energy per 1 meter of height, and the floor space is doubled;
(3) No internal ties, easy to clean and safe to operate, which facilitates the installation of automatic cleaning facilities, diversion, and keeping the water stored fresh and flowing;
(4) It is easy to combine in parallel, has little impact on uneven settlement, and is easy to maintain. Multiple tanks can be built quickly at the same time, or construction and expansion in phases can be flexible and convenient.
Feature 3 – Intelligent dynamic storage technology
Intelligent storage technology
Intelligent regulation and storage is based on continuous monitoring of pressure, flow, and liquid level. Through the analysis and learning prediction of the water supply time change curve, it automatically obtains the current regulation and storage target parameters and control strategies. It is a dynamic regulation process that follows changes in conditions:
Automatically put into power storage when needed, and automatically and appropriately adjust the compensation flow Q according to the actual power storage capacity and demand for the current period.Compensation flow rate Q is the basic parameter to achieve the regulation target, which can be understood as the ability to reduce the peak suction flow rate during peak periods (peak clipping).The storage volume V can be understood as the ability to reduce the total amount of water pumped during the peak period (cutting amount). The intelligent dynamic storage process makes peak cutting and cutting amount balanced.
Dynamic Optimization of Adjustment Target Parameters
The actual operating pump station may not be able to meet the design water supply capacity temporarily or for a long time, or it may be close to or exceed the design water supply capacity; the water supply volume changes in different seasons and different time periods (highest day, lowest day),It will also lead to different demand for regulation and storage, and the designed regulation and storage volume may be too large or too small. For this reason, the regulation and storage target parameters change dynamically.The initial regulation and storage control method is not complicated. By monitoring municipal pressure, regulation and storage is automatically put into use during peak periods. The initial regulation and storage parameters are automatically set according to the design capacity. The effect may not be optimal.Through continuous analysis, learning, and continuous optimization of storage parameters, we can ultimately achieve the maximum (best) storage effect using limited water storage volume.
Intelligent storage and water age optimization control
There is a certain correlation between storage compensation control and water age optimization control. Naturally, the shorter the water age, the better. The smaller the effective volume of the water tank, the more conducive to reducing the water age. The premise is that the demand for storage volume must be met.
When it is judged that the regulation and storage volume is large enough, the dual measures of automatic variable volume control (reducing the effective regulation and storage volume) and forced cyclic update during the low water supply period will be used to shorten the update cycle of water storage in the water tank (reduce the water age);When it is judged that the regulation and storage volume matches the regulation and storage demand appropriately, forced cycle update measures during the low period will be taken to optimize the water age.
Feature 4 – Intelligent control technology
Intelligent control design is the softwareization (implementation) of long-term accumulated professional knowledge, which is the outstanding advantage of KQF products
(1)Intelligent power-assist adjustment and storage function: refer to the above content.
(2) Intelligence helps water quality and sanitation: KQF pumping station has strengthened the implementation of water quality and sanitation technical measures, which has obvious characteristics.
- Developed a parallel split-type, cheap and reliable water tank inlet flow monitoring device. Based on continuous flow, water volume, and liquid level monitoring, a water age optimization control method was developed, which can automatically change the effective volume according to operational needs.This enables optimal control of the water storage update time (water age) of the water tank.
- Developed new technologies and methods for online monitoring of water quality. Through sampling, analysis, and comparison of various water samples, as well as through multi-dimensional comparative analysis of various water quality parameters and comprehensive analysis of historical data, reliable and effective early warning, alarm, and protection can be carried out.
(3) Intelligence assists pump station security: Through a series of intelligent sensing, including video surveillance, various security technical measures have been improved and implemented.
- Implemented monitoring and technical protection measures such as anti-freeze, heat protection, moisture-proof, fire protection, and lightning protection;
- Implemented security technical measures such as anti-theft and entry restriction, focusing on access control management and video monitoring;
- Implemented monitoring and fault countermeasures technical measures to prevent overflow and pipe burst accidents.
(4) Intelligence helps long-term continuous operation and more complete automation
In addition to its inherent design reliability, KQF products also focus on improving risk countermeasures for various faults and water outages, and strengthen continuous and reliable unattended operation. A series of new technologies (software) for intelligent sensing and adaptive control have been developed to achieve more complete automation.
- In addition to the traditional automatic switching of main and backup pumps, a dual control system (dual PLC, dual PID, mutual redundancy) is specially designed for dual modes;
- Developed non-inductive constant voltage control technology, which can still achieve constant voltage control when the sensor fails;
- Developed standard, multi-dimensional, full-parameter early warning, alarm, and protection functions;
- Developed system optimization control based on flow, which can adapt to changes in various working conditions;
- Developed non-same-frequency parallel speed regulation technology, which can adapt to the parallel speed regulation of pumps of different specifications.
Centralized supercharging and peak shaving in urban areas
Solve the problem of insufficient water supply capacity of the direct supply pipe network in the old city due to increased water consumption;
Pressurization and peak shaving at the end of the pipeline network
Solve the problem of insufficient water supply capacity at the end of the existing pipe network caused by increased water consumption;
Standard grid pumping station
Solve the problem of urban zoning standard water supply;
Suburban expansion, supercharging and peak shaving
Solve the problem of direct water supply pressure in the expansion and extension areas of urban water supply network;
Township water supply boosting and peak regulation
Solve the problem of integrated urban and rural water supply with the same pipe network, same water quality, and same service supply;
Other
Mid-way water transmission, highland water transmission, multi-water source water supply regulation and storage pumping stations, self-built pumping stations for factories, mines, and large construction sites, etc.
Specification model selection
KQF standard product selection, the full series has a total of 16 specification numbers, see Table 3. The standard specifications determine the basic parameters, floor area, and appearance dimensions L*W*H of this type of pump station. The basic parameters of each specification pump station can be adjusted within a certain range, and there are hundreds of different models of products. Please refer to Table 3 for explanation. KQF can provide products outside the specification range of Table 3 (non-standard products).
Matching water pump selection
KQF pump station provides three pump types to choose from: stainless steel stamped multi-stage pump KQDQE series, stainless steel single-stage pump KQLE series, and double-suction pump KQSN series (food-grade inner coating, stainless steel impeller).
KQF pump stations are usually equipped with 2 groups of 4-6 pumps in total and have 3 pump allocation plans. Usually, the pumps are allocated according to the complementary principle by default, and the pumps are allocated according to the total flow rate n and 1 (each pump has the same flow rate).
An example of a water pump configuration is as follows:
[Example 1] 2 groups of 4 pumps, 2:2 configuration, 3 in use and 1 in standby; both groups of pumps are selected according to 2/3 of the total flow rate;
[Example 2] 2 groups of 5 pumps, 3:2 configuration, 4 in use and 1 in standby; one group of pumps is selected according to 3/4 of the total flow (the other group of pumps is selected according to 2/4);
[Example 3] 2 groups of 6 pumps, 3:3 configuration, overall 4 in use and 2 in standby; both groups of pumps are selected according to 3/4 of the total flow rate;
[Example 4] 2 groups of 6 pumps, 3:3 configuration, overall 5 in use and 1 in standby; both groups of pumps are selected according to 3/5 of the total flow rate;
[Example 5] 2 groups of 6 pumps, 4:2 configuration, 5 in use and 1 in total; one group of pumps is selected according to 4/5 total flow (the other group of pumps is selected according to 2/5).
Note: For various pump configuration plans, the final actual pump configuration parameters and number of pumps should meet the design parameter requirements of the design institute.
Method 1
Select according to the rated water supply flow rate and 2-hour water volume of the pumping station. This method refers to Article 7.6.4 of GB/T50013-2018 “Outdoor Water Supply Design Standard” “Effective volume of the clear water tank of the water plant. In the absence of information,It can be determined based on 10%-20% of the maximum daily design water volume of the water plant.”
Method 2
The pump station is selected based on 30% of the rated water supply flow rate Qm and 3-hour water volume. This method refers to GB/T38594-2020. Compared with method 1, the water tank volume is selected to be smaller, equal to the rated flow rate and 0.9-hour water volume. The idea of this method is to limit the maximum suction flow to a certain level through storage compensation during peak hours, and the maximum storage target is positioned as follows:
Peak clipping is not less than 30%, clipping amount V=qt=0.3*3Qm
The actual regulation and storage operation is a dynamically changing process, and the compensation flow q (time t) is automatically calculated and adjusted according to the current demand:
Limited to 70% suction, 30% compensation, continuous compensation for 3 hours
Limited to 75% suction, 25% compensation, continuous compensation for 3.6 hours
Limited to 80% suction, 20% compensation, continuous compensation for 4.5 hours
Limited to 85% suction, 15% compensation, continuous compensation for 6 hours
Actual project selection –
- For pumping stations with a daily water supply of more than 10,000 tons, you can consider selecting the storage volume according to method 1;
- Pumping stations with a daily water supply of less than 10,000 tons (water supply peaks and valleys are large, and the hourly variation coefficient is large) can be considered using Method 2 or similar peak and volume reduction goals;
- Select the storage capacity according to local water management requirements.
Water tank specifications and quantity selection –
- The standard water tank of KQF pump station is cylindrical, usually less than 15m in diameter and 6-10m in height. Please refer to Table 1 for the specifications of cylindrical water tanks; the quantity should usually be no less than 2.Usually, 2, 3, 5, or 7 water tanks are selected according to the volume requirements. The configuration of multiple water tanks is conducive to diversion, maintenance, and structural layout of the pump station;
- In order to facilitate the matching of volume and layout, water tank configurations of different diameters as shown in Table 1 can also be used;
- The KQF pumping station can optionally be equipped with a rectangular water tank (common height is 3 meters), refer to the standard design drawing 12S101.
Cylindrical water tank series specification table
| Diameter Volume Height |
6m | 8m | 10m | 12m | 15m |
| 6m | 170m³ | 301m³ | 471m³ | — | — |
| 7m | 198m³ | 352m³ | 550m³ | 791m³ | — |
| 8m | 226m³ | 402m³ | 628m³ | 904m³ | 1413m³ |
| 9m | 254m³ | 452m³ | 707m³ | 1017m³ | 1590m³ |
| 10m | — | — | 785m³ | 1130m³ | 1766m³ |
In order to adapt to the parallel operation of two sets of pumps with different lifts and to adapt to variable operating conditions under different conditions, the KQF regulating and accumulating pumping station will involve a series of in-depth application issues of frequency conversion technology. Generally, full frequency conversion driving should be used.Each water pump is equipped with one frequency converter, please refer to the technical specifications table.
(1) Application selection consulting service: KQF regulating and storage pumping station is both a product and a project. It requires all parties to participate in-depth in the whole process of the project. There may be a series of optimization choices, partial considerations, right and wrong judgments, and difficult choices. , the company provides complete and detailed consulting services. Please consult our company’s technical support and fill out the project requirements form (refer to the attached table) based on full research and in-depth communication.
(2) Pay attention to the scope of supply: KQF is a fully prefabricated, complete integrated supply, and on-site installation product (turnkey project). Please refer to the equipment composition description and pay attention to the consistency of the scope of supply with design drawings and schedules. And pay attention to the requirements such as reserving expansion interfaces.
| Basic technical specifications table of KQF series standard products | ||
| Water supply capacity | Water supply pressure Boost range |
P=20-60mH₂O is determined by the specific model, (P outlet pressure), Boosting range: fully variable frequency 0.4-1.0H adjustable, (H water pump lift); Partial frequency conversion is adjustable from 0.7-1.0H |
| Water supply flow | 150-2500m3/h, determined by specific model | |
| Constant voltage performance | Constant voltage accuracy | ≤1mH,O (debugging parameters) |
| Stable schedule | ≤30S, partial frequency control, (debugging parameters) ≤20S, full frequency control, (debugging parameters) |
|
| Pressure shock | —— | |
| Adjust storage capacity | Adjust water tank (volume) | Optional: The water tank volume is matched according to the rated water supply flow rate and 2-hour water volume of the pump station. Or matched with rated water supply flow and 0.9 hour water volum |
| Compensation flow | During the adjustment process, it is automatically adjusted according to needs. If the compensation flow rate is increased, the compensation time will be shortened. | |
| Compensation time | Based on municipal pressure monitoring, storage compensation is automatically put into operation during peak water supply periods. | |
| Hygienic performance | Water age control | Automatic optimization, using forced cycle update and automatic variable volume control to optimize water age. |
| Equipment material | The flow-passing parts (pumps, valves, tanks, and pipelines) are made of 304 stainless steel, and the pressure tank and water sealing materials meet hygienic requirements. | |
| Water quality online monitoring | Optional: turbidity, residual chlorine, ph value, total solid solution (TDS) | |
| Pump station energy efficiency | Pump efficiency | Not less than the energy-saving evaluation value specified in GB119762 |
| Motor efficiency | Not lower than level 3 energy efficiency specified in GB18613 | |
| Internal pressure loss | Less than 5mH₂O | |
| Pumping station energy efficiency | The rated unit energy consumption is better than 0.46kWh/m³MPa; the rated efficiency is not less than 60%; | |
| Operating noise | Test outside the pump room ≤75dB (power less than 30kW); ≤82dB (37-150kW) | |
| Continue to operate | Designed for long-term unattended operation, measures to ensure continuous water supply in case of failure: refer to the sample description | |
| Seismic design | Calculated according to earthquake intensity 7 (0.1g); | |
| Windproof design | Wind load is calculated as 0.45kPa | |
| Control cabinet design | Drag method | Adopt full frequency conversion drag |
| Operation method | Manual operation, automatic operation | |
| Start mode | Variable frequency pump soft start and soft stop | |
| Control method | Multi-stage constant pressure control at the water outlet of the pump station (6-9 levels of voltage transformation) | |
| Operation mode | The variable frequency pumps in the same unit run alternately, and the two units run in parallel in complementary dual mode. | |
| Speed mode | In the same unit, the speed is adjusted at the same frequency (equal flow distribution of each pump), and when two units are connected in parallel, the speed is adjusted at different frequencies. | |
| HMI | Full performance parameter display: pressure, flow, frequency, power parameters, energy efficiency parameters, touch screen operation. | |
| Early warning warning | Early warning system based on full-parameter, multi-dimensional, historical data comparative analysis | |
| Protection level | Motor IP54; control cabinet IP41-IP55 optional. | |
| Working conditions | Power supply | 380V±10%, 50HZ±5%, should have good grounding wire, grounding resistance less than 4 ohms |
| Applicable environment | The lowest monthly average temperature is not less than 4℃ (without insulation layer), The altitude does not exceed 1000 meters. |
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| Surroundings | The surrounding area is open and the air is fresh; stay away from corrosive, flammable, toxic, gas and liquid places Stay away from hospitals, garbage dumps, markets and other places |
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