Water source direct expansion air conditioning system suitable for laboratory thermal environment control

Abstract

The utility model discloses a water source direct expansion air conditioning system suitable for laboratory thermal environment control, which comprises water source direct expansion air conditioning units arranged in parallel, and is characterized in that water side heat exchangers of the water source direct expansion air conditioning units are connected through a public water loop, a circulating water pump and an intermediate heat exchanger are arranged in the public water loop, and the intermediate heat exchanger is provided with an auxiliary cold and heat source; each water source direct expansion air conditioning unit freely runs in a refrigerating or heating mode according to needs through an independently-arranged stop valve. Water source direct expansion air conditioning units of different air conditioning zones are connected through a public water loop, so that energy among the air conditioning units of the different air conditioning zones is effectively recycled, all water side-fluorine side energy consumption metering is managed in a unified mode, efficient and stable operation is guaranteed, and all-dimensional energy-saving control is achieved with the minimum comprehensive energy consumption as the target. And through combination of water and fluorine, advantages are combined, and wider application scenarios and expansibility are achieved.

Description

Technical Field

[0001] This utility model relates to a high-precision temperature and humidity air conditioning technology for laboratories, and in particular to a water source direct expansion air conditioning system suitable for laboratory thermal environment control. Background Technology

[0002] Laboratories are a special type of building, requiring the indoor temperature to be maintained within a certain range to meet both the requirements of experimental operations and the comfort requirements of the experimental personnel. The air conditioning load of laboratories differs significantly from that of conventional buildings. For example, some rooms require cooling year-round; and some rooms may have varying heating and cooling loads depending on the purpose of the experiments, requiring heating at certain times and cooling at others.

[0003] If conventional air conditioning is used, whether it is a single unit or a multi-unit system, the following two problems exist: First, there are many pipelines, the connection between indoor and outdoor units is long, the loss of cold and heat transfer media is large, and the operating efficiency is low; second, when all air conditioning systems are running in cooling and heating modes at the same time, the energy consumption is high and it is uneconomical. Summary of the Invention

[0004] The purpose of this invention is to solve the above problems and provide a water source direct expansion air conditioning system suitable for laboratory thermal environment control. It has the advantages of significant energy saving, high efficiency and stable operation, strong scalability and wide application scenarios.

[0005] The above-mentioned technical problems of this utility model are mainly solved by the following technical solution: a water source direct expansion air conditioning system suitable for laboratory thermal environment control, including water source direct expansion air conditioning units arranged in parallel, characterized in that the water-side heat exchangers of the water source direct expansion air conditioning units are connected through a common water loop, and a circulating water pump and an intermediate heat exchanger are provided in the common water loop, with the intermediate heat exchanger equipped with an auxiliary cold and heat source; each water source direct expansion air conditioning unit operates freely in cooling or heating mode as needed through a separately configured shut-off valve.

[0006] In the aforementioned water source direct expansion air conditioning system suitable for laboratory thermal environment control, preferably, a constant pressure water supply device is also provided on the public water loop.

[0007] In the aforementioned water-source direct expansion air conditioning system suitable for laboratory thermal environment control, preferably, the intermediate heat exchanger is connected to the common water loop via a shut-off valve.

[0008] In the aforementioned water-source direct expansion air conditioning system suitable for laboratory thermal environment control, preferably, the auxiliary cold and heat source comes from a cooling tower or boiler, or a low-grade resource.

[0009] In the aforementioned water source direct expansion air conditioning system suitable for laboratory thermal environment control, preferably, the low-grade resources include a pipeline system consisting of groundwater, surface water, process wastewater, industrial waste heat, and reclaimed water.

[0010] In the aforementioned water-source direct expansion air conditioning system suitable for laboratory thermal environment control, as a preferred embodiment, the water-side and refrigerant-side energy consumption meters of the water-source direct expansion air conditioning unit are connected to the same control platform, and the system is regulated based on the criterion of minimizing overall energy consumption.

[0011] In the aforementioned water source direct expansion air conditioning system suitable for laboratory thermal environment control, preferably, the parallel-arranged water source direct expansion air conditioning units can be individually metered for heating, cooling and energy consumption via shut-off valves.

[0012] In the aforementioned water source direct expansion air conditioning system suitable for laboratory thermal environment control, as a preferred embodiment, rooms that are cooled year-round and rooms that frequently switch between cooling and heating modes are respectively divided into the same air conditioning zone and equipped with independent water source direct expansion air conditioning units.

[0013] In the aforementioned water-source direct expansion air conditioning system suitable for laboratory thermal environment control, as a preferred embodiment, an auxiliary cold source is also connected to the common water loop via a shut-off valve.

[0014] In the aforementioned water-source direct expansion air conditioning system suitable for laboratory thermal environment control, preferably, there are no fewer than two intermediate heat exchangers; the water in the common water loop is at room temperature.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] This technical solution uses a water-source direct expansion air conditioning unit. Through the design of a common water loop and the configuration of auxiliary cold and heat sources, it can meet the temperature requirements of the laboratory while achieving significant energy-saving benefits.

[0017] This device connects water-source direct expansion air conditioning units in different air-conditioning zones via a common water loop. Each water-source direct expansion air conditioning unit can freely operate in cooling or heating mode as needed, with energy recovery handled by the common water loop, achieving energy transfer between units in different air-conditioning zones and resulting in energy-efficient system operation. Furthermore, it offers a wide range of auxiliary cold and heat sources, enabling multi-energy complementarity.

[0018] The water source direct expansion air conditioning unit in this system is located close to the air conditioning zone it serves, and is closer to the indoor unit, thus achieving higher performance.

[0019] The system's public water loop has a stable water temperature, and the capacity of the water source direct expansion air conditioning unit is not affected by the outdoor summer heat or winter cold, resulting in strong continuous operation and high comfort.

[0020] This system integrates the water-side and refrigerant-side energy consumption metering of water source direct expansion air conditioning units into the same platform for unified management. While ensuring efficient and stable operation, it aims to achieve comprehensive energy-saving control and management with the goal of minimizing overall energy consumption.

[0021] This water-source direct expansion air conditioning system combines the advantages of water and fluoride, offering broader application scenarios and greater design flexibility, and achieving good economic and social benefits. Attached Figure Description

[0022] Figure 1 This is a system diagram of this utility model.

[0023] In the diagram: 1-Circulating water pump, 2-Intermediate heat exchanger, 3-Auxiliary cold source, 4-Water source direct expansion air conditioning unit, 5-Constant pressure water supply device, 6-Auxiliary cold and heat source. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0025] Regarding the type of water-source direct expansion air conditioning unit, it can be a water-cooled direct expansion unit air conditioner or a water-cooled direct expansion multi-split air conditioner. This embodiment will use the latter as an example for explanation.

[0026] like Figure 1 As shown in the figure, this embodiment discloses a water-source direct expansion air conditioning system suitable for laboratory thermal environment control. It includes water-source direct expansion air conditioning units 4 arranged in parallel within the laboratory. All water-side heat exchangers of the water-source direct expansion air conditioning units 4 are connected via a common water loop to form a circuit. The common water loop includes a circulating water pump 1 and an intermediate heat exchanger 2. The intermediate heat exchanger 2 is equipped with an auxiliary cold / heat source 6 and is connected to the common water loop via a shut-off valve. A constant pressure water supply device 5 is also installed on the common water loop and is connected to an auxiliary cold source 3 via a shut-off valve. The auxiliary cold source 3 can be a closed-loop cooling tower.

[0027] Each water source direct expansion air conditioning unit 4 operates freely in cooling or heating mode as needed through a separately configured shut-off valve, allowing each water source direct expansion air conditioning unit 4 to independently measure cooling and heating capacity and energy consumption. Furthermore, the water-side and refrigerant-side energy consumption meters of the water source direct expansion air conditioning unit 4 are all connected to the same control platform, and are regulated based on the criterion of minimizing overall energy consumption.

[0028] Auxiliary heat and cold sources 6 come from cooling towers or boilers, or low-grade resources. Low-grade resources include pipeline systems consisting of groundwater, surface water, process wastewater, industrial waste heat, greywater, etc.

[0029] The working principle and application will be further explained below:

[0030] Operating characteristics of water source direct expansion air conditioning system: When each air conditioning zone operates in cooling and heating modes simultaneously, heat absorption and release occur simultaneously in the common water loop, which can realize the effective transfer of energy between direct expansion air conditioning units in different air conditioning zones and achieve energy recovery effect.

[0031] During summer operation, assuming all water source direct expansion air conditioning units 4 are cooling, the common water loop needs to discharge the condensation heat of each water source direct expansion air conditioning unit 4, which is mainly dissipated by the cooling tower.

[0032] During transitional seasons and winter operation, some air conditioning zones utilize water-source direct expansion air conditioning units 4 for cooling and others for heating. The cooling units release heat into the water loop, while the heating units absorb heat from the water loop. The difference between the two is calculated. If heat is released, it is replenished by auxiliary cold source 3; if heat is absorbed, it is replenished by auxiliary heat source 6. In practical applications, a closed-loop cooling tower is preferred as the auxiliary cold source 3.

[0033] In this embodiment, the water in the public water loop is at room temperature, maintained at around 15–35°C year-round, and generally does not require insulation. Each air conditioning zone can freely select its cooling and heating modes, offering functionality similar to a four-pipe water system.

[0034] Each air conditioning zone operates independently and can be individually metered for heating, cooling, and energy consumption.

[0035] The system has low requirements for water temperature when heating, can utilize low-grade energy, and is suitable for waste heat and residual heat utilization. When cooling, the system can utilize natural cold sources and wastewater resources, and is suitable for groundwater, surface water, and reclaimed water utilization.

[0036] Furthermore, technical measures for water source direct expansion air conditioning systems:

[0037] Water source direct expansion air conditioning units require constant flow. When arranging the terminal loops, the hydraulic balance between loops should be considered. Under the premise of economic rationality, a parallel flow system is preferable. Branch loops should not be too large, and balance calculations should be performed between loops; balancing valves should be installed if necessary.

[0038] Air conditioning zone division: Rooms that are cooled year-round and rooms that frequently switch between cooling and heating modes according to process requirements should be divided into the same air conditioning zone and equipped with independent water source direct expansion air conditioning units.

[0039] System cooling and heating balance calculation: Calculate the cooling load or heating load of the system on a typical design day, estimate the heat release and heat absorption transferred to the water loop, and configure the corresponding auxiliary cold source and heat source according to the maximum difference between the two.

[0040] Selection of auxiliary cold and heat source equipment:

[0041] 1. Cooling tower: A closed-loop cooling tower is adopted.

[0042] Q = Qz(1 + 1 / COPe)

[0043] L=3.6Q / (C.(t1-t2))

[0044] In the formula, Qz is the maximum cooling load in summer, in KW; Q is the total condensing heat output of the water source direct expansion air conditioning unit, in KW; COPe is the coefficient of performance of the water source direct expansion air conditioning unit; L is the rated flow rate of the cooling tower, in cubic meters per hour; C is the specific heat of water, 4.186 J / kg·℃; t1 and t2 are the inlet and outlet water temperatures of the cooling tower, in℃.

[0045] 2. Intermediate heat exchanger: Plate heat exchanger is used.

[0046] The heat exchange temperature difference is calculated as 2-3℃, and the inlet and outlet water temperature difference is 5℃.

[0047] There shall be no fewer than two heat exchangers, and when one of them stops operating, the heat exchange capacity of the remaining heat exchangers shall not be less than 75% of the total heat exchange capacity.

[0048] 3. Auxiliary heat source:

[0049] The heat absorption and release energy of the common water loop for maintaining the normal operation of the water source direct expansion air conditioning system should be balanced. When some air conditioning zones are cooling, the water source direct expansion air conditioning unit 4 releases heat into the water loop, and when some air conditioning zones are heating, the water source direct expansion air conditioning unit 4 absorbs heat from the water loop. When the heat absorbed is greater than the heat released, the difference needs to be supplemented by an auxiliary heat source. The maximum value generally occurs in winter.

[0050] The total load of the auxiliary heat source is calculated using the following formula:

[0051] Q = Heat absorbed by the water loop - Heat released by the water loop = Qr(1-1 / COPh) – Ql(1+1 / COPe)

[0052] In the formula: Q is the total load of the auxiliary heat source, in KW; Qr is the total winter heating load, in KW; Ql is the total winter cooling load, in KW; COPh is the heating coefficient of the water source direct expansion air conditioning unit; COPe is the cooling coefficient of the water source direct expansion air conditioning unit.

[0053] The above embodiments connect direct expansion air conditioning units in different air conditioning zones through a common water loop, enabling effective energy recovery and utilization between these units and achieving energy savings in system operation. By integrating water-side and refrigerant-side energy consumption metering of the water-source direct expansion air conditioning system into a unified platform for management, comprehensive energy-saving control and management can be achieved while ensuring efficient and stable operation and minimizing overall energy consumption. The water-source direct expansion air conditioning system, through the combination of water and refrigerant, offers both advantages, broader application scenarios, and greater design flexibility, resulting in significant economic and social benefits.

[0054] The above embodiments are illustrative of the present invention and not intended to limit it. Although the present invention has been described in conjunction with preferred embodiments, it should be understood that the present invention is not limited to the preferred embodiments. Those skilled in the art can make various equivalent modifications and substitutions to the technical solutions of the present invention based on its teachings. Therefore, the scope of the present invention should be defined by the claims, and all such equivalent modifications and substitutions fall within the protection scope of the present invention.

Claims

1. A water source direct expansion air conditioning system suitable for laboratory thermal environment control, comprising water source direct expansion air conditioning units (4) arranged in parallel, characterized in that... The water-side heat exchanger of the water source direct expansion air conditioning unit is connected through a common water loop. The common water loop is equipped with a circulating water pump (1) and an intermediate heat exchanger (2). The intermediate heat exchanger is equipped with an auxiliary cold and heat source (6). Each water source direct expansion air conditioning unit can freely operate in cooling or heating mode as needed through a separately configured shut-off valve.

2. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, characterized in that, The public water loop is also equipped with a constant pressure water supply device (5).

3. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, characterized in that, The intermediate heat exchanger (2) is connected to the common water loop through a shut-off valve.

4. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1 or 3, characterized in that, The auxiliary heat source (6) comes from a cooling tower or boiler, or from low-grade resources.

5. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 4, characterized in that, The low-grade resources include pipeline systems consisting of groundwater, surface water, process wastewater, industrial waste heat, and reclaimed water.

6. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, characterized in that, The water-side and refrigerant-side energy consumption meters of the water source direct expansion air conditioning unit (4) are connected to the same control platform and are regulated based on the criterion of the lowest comprehensive energy consumption.

7. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, 2, 3, or 6, characterized in that, The parallel-arranged water source direct expansion air conditioning unit (4) can be individually metered for heating, cooling and energy consumption through a shut-off valve.

8. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, characterized in that, For rooms that are cooled year-round and rooms that frequently switch between cooling and heating modes, they are divided into the same air conditioning zone and equipped with independent water source direct expansion air conditioning units (4).

9. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, characterized in that, The public water loop is also connected to an auxiliary cold source (3) via a shut-off valve.

10. A water-source direct expansion air conditioning system suitable for laboratory thermal environment control according to claim 1, characterized in that, There shall be no fewer than two intermediate heat exchangers; the water in the public water loop shall be at room temperature.

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