RU2767130C1 - Device for heat recovery of domestic waste water of building - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to heat engineering, and more specifically to a device for heat recovery of domestic waste water. Device is intended for useful use of heat of domestic waste water of residential, public, administrative and industrial buildings of enterprises in the regions of the Arctic, Antarctica, the Far North and the Far East, in areas with permafrost soils. In the household waste water heat recovery device of a building, comprising a refrigerating plant with a compressor-condenser unit and an evaporation unit, the compressor-condenser unit is placed in a heated room equipped with a heating system, evaporation unit is arranged in process room and is made in the form of ice generator unit, into which purified waste water is supplied, and ice behind ice generator unit is removed from process room. Ice generator can be made in the form of a unit for production of block ice or in the form of a plant for production of granulated or flake ice, which is then pressed into blocks. To control temperature in the heated room, an automatic control system is used, which provides a given temperature mode by changing the heat output of the heating system. On the purified waste water pipeline to the ice-generating plant, a switching device is installed to drain waste water into the sewage system with elevated or surface laying of pipelines. Heating system can be equipped with an air or water circuit for transferring the body to the heated room and contain boilers on hydrocarbon types of fuel, water or electric air heaters. Heated room can have external units of air conditioning systems.

EFFECT: increase of specific heat removal at cooling of waste water, simplification of design and possibility of heat recovery of domestic waste water in conditions of the Arctic zone of Russia, in areas with permafrost soils.

7 cl, 1 dwg

Description

The invention relates to the field of thermal power engineering, and more specifically, to a device for heat recovery from domestic wastewater. The device is designed for the beneficial use of heat from domestic wastewater from residential, public, administrative, domestic and industrial buildings of enterprises in the regions of the Arctic, Antarctica, the Far North and the Far East, in areas with permafrost soils. The priority areas of application of the invention are located and projected in areas with permafrost soils enterprises of mining, commercial, processing, scientific and defense organizations, ministries and departments. It is in these areas that the problem of maximum heat utilization and minimal damage to the environment is most acute.

There are a number of technical solutions aimed at solving this problem. So from the prior art there is a method of heating and air conditioning a building by using heat sources and heat pumps containing indoor and outdoor units, according to which the outdoor units of heat pumps are placed in rooms heated by heat sources, and the indoor units are placed in air-conditioned rooms, automatically maintain normalized air temperature in all rooms by transferring heat from rooms heated by heat sources to conditioned rooms by means of indoor units of heat pumps, and in case of excess heat in conditioned rooms, indoor units automatically switch to cooling mode, and the heat they remove is transferred, if necessary, to other conditioned rooms or heat is transferred through outdoor units to rooms with outdoor units, providing a reduction in the load on heat sources and reducing fuel and / or electricity consumption, and in rooms with outdoor units in the summer achieve the optimal temperature by using a ventilation system with adjustable air exchange rate using automatic air valves, the degree of opening of which is changed depending on the outside temperature, which allows the use of heat pumps for heating the building due to ambient heat (patent RU 2 725 127 C1, IPC F24D 3/18, F24F 1/00, F24F 7/00, publ. 06/29/2020).

The disadvantage of this method of heating and air conditioning the building is a limited list of heat sources: air heaters running on hydrocarbon fuel or electricity, and outdoor air conditioner units operating in cooling mode in the summer.

Also known from the prior art is a wastewater heat recovery device for heating water in the heat supply systems of a building from 58°C to 88°C using two-stage heat pumps (Sultanguzin I.A., Potapova A.A., “High-temperature heat pumps of high power for heat supply" // "News of heat supply" No. 10 (122), October 2010). Waste water is used as a heat source, which is cooled in the evaporator by 6°С (from +16°С to +10°С). The article describes a device for heat recovery of domestic wastewater from a building, containing a refrigeration unit with a compressor-condenser unit and an evaporator unit. In this case, the specific heat removal during wastewater cooling is 25.2 kJ/kg.

This device on the basis of the totality of features is a prototype of the claimed device for heat recovery of domestic wastewater.

The disadvantages of the prototype are:

- low specific heat removal during wastewater cooling,

- the complexity of the technical execution of the prototype: two-stage chillers are much more difficult to manufacture and operate than widely used single-stage chillers,

- the impossibility of using the prototype in the conditions of the Arctic zone of Russia in areas with permafrost soils.

The technical task of the proposed device is to eliminate these shortcomings.

The technical result of the claimed device is:

- heat recovery from household wastewater in the conditions of the Arctic zone of Russia, in areas with permafrost soils,

- use of serially produced equipment with single-stage refrigeration machines for wastewater recuperation,

- a significant increase in specific heat removal from domestic wastewater (up to 438 kJ/kg),

- reduction of energy consumption for heating the building with a simultaneous reduction of harmful emissions into the environment (thermal energy, carbon dioxide, nitrogen oxides).

The solution of the set technical problem and the achievement of the desired result are ensured by the fact that in the device for heat recovery of domestic wastewater from the building, containing a refrigeration unit with a compressor and condenser unit and an evaporator unit, the compressor and condenser unit is located in a heated room equipped with a heating system, and the evaporator the unit is located in the process room and is made in the form of an ice plant, into which treated wastewater is supplied, and the ice behind the ice plant is removed from the process room. In this case, the ice-maker can be made in the form of a plant for the production of block ice or in the form of an installation for the production of granular or flake ice, which is then pressed into blocks. To control the temperature in the heated room, an automatic control system is used to ensure the specified temperature regime by changing the heat output of the heating system. On the treated wastewater pipeline leading to the ice-making plant, a switching device is installed to divert wastewater into the sewer during the summer period with above-ground or surface laying of pipelines.

The heating system can be provided with an air or water circuit for transferring the body to the heated room and contain boilers for hydrocarbon fuels, water or electric air heaters. The heated room may have outdoor units of air conditioning systems.

The essence of the invention is illustrated by a figure.

The figure shows a diagram of the proposed device for heat recovery of domestic wastewater from the building.

In the technological room 1, which has an exit to the outside through the shipping drive - lock 2, there is a station 3 for the treatment of domestic wastewater, an evaporation unit 4 in the form of an ice maker and a flake ice press 5. When using a block ice machine, there is no need to use a press 5. A compressor-condenser unit 7 is located in the heated room 6. The room 6 is also equipped with a traditional heating system containing a heat generator, for example, a heating boiler 8, a heat pipe 9, a pump 10, a fan heater (air heater) 11 and a system for controlling the air temperature in the room by changing the heat output of the generator heat. It is possible to use a water heating system to transfer heat from the boiler 8 to the room. The pipeline line 12 is used to bypass the evaporation unit 4 in the summer season. In room 1 there is also a conveyor 13 for moving the pressed ice to the shipping storage - gateway 2.

The proposed device for heat recovery of domestic wastewater from the building operates as follows.

During the heating season (cold period of the year with a negative outdoor temperature) in the heated room 6 automatically normalized air temperature is maintained, for example, 20-22°C according to SanPiN 2.1.2.1002-00. 2.1.2. (as amended on August 21, 2007) as a result of using heat from the generator 8 and heat removed from the compressor and condenser unit 7. In this case, the generator 8 is the main source of heat, and the compressor and condenser unit 7 is additional. This additional heat is obtained from domestic wastewater, which is treated at station 3. The treated wastewater is fed into the evaporation unit 4, where it gives off heat to the refrigerant and freezes in the form of flake ice. The scaly years are compressed by a 5 press into briquettes, which are then moved along the 13 conveyor to the shipping storage - gateway 2 for further disposal outside the building.

The heat from the compressor-condenser unit 7, which is an additional heat source in the heated room 6, reduces the heat load on the heating system and, therefore, leads to a decrease in the consumption of a non-renewable energy source - fossil fuel. As a result, there is a reduction in the environmental burden on the environment.

In the summer period of the year, at a positive outdoor temperature, when the heating system is turned off and there is no need for additional heat sources, treated wastewater can be removed from the building bypassing the evaporation unit 4 through the pipeline line 12, made using the technology of above-ground or ground-based pipeline laying, which is a great advantage for permafrost regions in terms of saving capital and operating costs and increasing environmental efficiency.

The economic effect of using the proposed device for heat recovery of domestic wastewater is illustrated by an example.

Example

Household wastewater at a temperature of 20°C with a flow rate of 10 m/day (0.1157 kg/s), which has been treated in a block-modular station for the treatment of household wastewater model STOV BIO-10, is sent to a two-block ice maker of flake ice models FF10AS, where they are cooled to 0°C, then frozen, after which the ice is supercooled to minus 10°C, pressed into blocks, for example, weighing 5 kg, the blocks are moved on the conveyor 5 to the shipping storage lock 2 and removed from the building for transportation to a storage or disposal facility.

The air-cooled condensing unit is located in a heated utility room of a building (facility), for example, in a mechanical repair shop, garage, warehouse, etc., in which a constant temperature is maintained, for example, +20°C. The most economical and efficient is the placement of the condensing unit in the engine room according to the patent RU 2725127 C1.

In this example, the heated room is equipped with a heating system with an adjustable heat output of up to 200 kW.

The amount of heat Q _lg , kJ, removed per day from 10 m of water as a result of its cooling, freezing and supercooling of ice, will be:

Q _lg \u003d _G⋅ (C vd _⋅t vd + C _ld ⋅t _ld + q _ld ) \u003d 4380000 kJ / day (50.694 kW)

where

Q _lg - the amount of heat Q _lg , kJ / day,

G=10000 kg/day - consumption of frozen water,

C vd \ _u003d 4200 J / (kgK) - specific heat capacity of water,

С ld \ _u003d 2100 J / (kg K) - specific heat capacity of ice,

q _m \u003d 333000 J / kg - specific heat of ice melting,

t vd \ _u003d 20 ° С - temperature difference when cooling water,

t ld \ _u003d 10 ° C - temperature difference during supercooling of ice.

The power consumed by the condensing unit is 48 kW (according to the technical data sheet).

Consequently, with the continuous operation of the device, the heating system will receive an additional power equal to 98.7 kW, and will reduce energy consumption for space heating by almost half (by 49%).

The above calculations show the industrial applicability of the proposed device for heat recovery of domestic wastewater from the building.

Claims (7)

1. A heat recovery device for domestic wastewater from a building, containing a refrigeration unit with a compressor and condenser unit and an evaporator unit, characterized in that the condenser unit is located in a heated room equipped with a heating system, and the evaporator unit is located in the process room and is made in the form of an ice plant, into which treated wastewater is supplied, and the ice behind the ice plant is removed from the process room. 2. The device according to claim. 1, characterized in that the ice plant is made in the form of a unit for the production of block ice. 3. The device according to claim. 1, characterized in that the ice machine is made in the form of a plant for the production of granular or flake ice, which is then pressed into blocks. 4. The device according to claim 1, characterized in that the heated room is equipped with an automatic air temperature control system by changing the heat output of the heating system. 5. The device according to claim 1, characterized in that a switching device is installed on the treated wastewater pipeline leading to the ice-making plant for draining wastewater into the sewer during the summer period with above-ground or ground-based pipelines. 6. The device according to claim. 1, characterized in that the heating system has an air or water circuit for transferring the body to the heated room and contains boilers for hydrocarbon fuels, water or electric air heaters. 7. The device according to claim 6, characterized in that the heated room contains outdoor units of air conditioning systems.

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