Heat from Rotterdam

Use waste heat from the process industry and waste processing for district heating, and both gas consumption andCO2 emissions go down significantly. On that premise, Gasunie subsidiary WarmtelinQ is building a large heat transport network in South Holland. The Engineer visited the works.The nearly 30-kilometre transport pipeline from Botlek to The Hague is ready. As a finishing touch, a heat transfer station is now under construction. Eventually, this pipeline will transport industrial residual heat from Rotterdam in the form of hot water to The Hague's district heating system: heat released from industrial processes in the port area that would otherwise be lost.We are standing in Hall 5 of the 100-year-old gas power plant building in The Hague. This was once where electricity for HTM's trams was generated, and later for city lighting and the entire city. During the oil crisis, residual heat became interesting and the Hague heat network was created. 'The municipality wants to make the city more sustainable, and part of that is to get this location off the gas as early as next year,' says project manager Remco de Boer, responsible for the realisation of the heat transfer station (WOS). This means that Gasunie subsidiary WarmtelinQ must also be ready to supply heat to the city grid by then. The Unicycle power plant, which currently produces heat and is gas-fired, can then go on standby.Twee grote buizen komen de grond uit aan de rand van het terrein en vervolgen zigzaggend hun weg naar Hal 5. Dit zijn de toe- en afvoerleiding van warmte uit Rotterdam. Foto: De IngenieurConductorHall 5 still contained asbestos and chromium 6. Now that everything has been remediated, the heat transfer station can be installed in the hall. 'This is what I call a brownfield, building something in a place where something else used to be,' says De Boer, who, as a chemical technologist, has more than 20 years' experience with this kind of project in the oil and gas industry at BP and Total. 'We were doing sustainability, but it was too slow for me. While searching, I came across WarmtelinQ. Using industrial waste heat in urban areas, that's really making a social impact.'Now he enthusiastically manages 'like a conductor' a large team of engineers, from design to construction, operation and maintenance. 'Everyone must have the same goal in mind, because next heating season, the WOS and the transmission grid must be fully operational. We work very hard to deliver on schedule, and if we don't, I will look at how we can accelerate. That's my role.'Build it cleanA large board in Hall 5 displays all permits granted for work by contractors. 'Every activity needs a permit. Everything is also carefully recorded, certified, documented and given identification numbers. That has to do with safety, and also with quality and soon with maintenance.'There are pieces of the heat pipeline in the hall, all temporarily sealed or capped. According to De Boer, ' Build it clean'. nothing should end up in a pipe, of course. And a clean workplace is a safe workplace. Moreover, we are guests on Uniper's premises.'Hall 5 used to house the gas generators to make hot water for power. Now the supply pipe from WarmtelinQ enters the building and goes directly to the two heat exchangers installed there on the ground floor at the end of March.Open ontgraving. Foto: WarmtelinQFourteen tonnesThe heat exchangers are specifically designed for the power needed for the city: each can deliver 35 megawatts. The heat exchangers are not very big, De Boer thinks: it is a block of two by three metres with a depth of one and a half metres. 'But it does weigh 14 tonnes.' That there are two heat exchangers has to do with redundancy. If one is out of service for maintenance, sufficient heat can still be supplied.In WarmtelinQ's heat exchanger, heat is transferred to Eneco, which manages The Hague's district heating. On the first floor in Hall 5 is WarmtelinQ's control and computer room, connected to a control centre in Groningen. 'We measure temperatures and flow rates, so we know how much heat is transferred. And Eneco eventually gets an invoice for that.'Eind maart werd de eerste warmtewisselaar Hal 5 binnengetakeld. Foto: WarmtelinQTestingA huge flow meter to take these measurements is still loose on the ground awaiting installation. First, the entire system has to be filled with water(total fill), pressurised and tested. It is actually a central heating boiler, says De Boer. 'Only ten thousand times bigger.'Every activity in the Hall requires a permit. For De Boer, that means constant talking, tuning and switching. Because Eneco is also building their rooms on the first floor and Uniper itself is busy with building maintenance. In a construction shack in Hall 5, De Boer shows the 3D-engineered model of the building, WOS and all pipes on the computer. 'The challenge is how to get everything integrated on one site. Everything has to fit together.'The first tests will follow after the summer, but even here the effects of grid congestion are being felt. 'We need power from Eneco. To do so, Eneco must first request a power cable from Stedin to go to our transformers. That has to be done before the summer. It's a critical timeframe.'Horizontaal gestuurde boring. Foto: WarmtelinQRijswijk-LeidenThat good preparation is essential for implementation, construction manager Ton Gombault knows better than anyone else. He points to the large map on the wall of the visitors' room in the The Hague office, showing the 25-kilometre Rijswijk-Leiden route. This is the job he has to do for WarmtelinQ over the next two years. Heat must be supplied around the summer of 2028. 'If we don't meet that end date, we will be fined by Vattenfall.' That is the energy supplier that distributes heat via the district heating network in Leiden. WarmtelinQ, like TenneT for electricity, only provides heat transport, not local distribution.The entire route has been cut into small pieces and is being carried out by just two contractors, A.Hak and Hanab. Gombault, a mechanical engineer by origin, was used to something different at his previous employer Shell. 'In a working plant, we had to install a new component with twenty contractors. That was complex. The challenge here is in the preparation: if it's not right, the work comes to a standstill. We are now in the transition from preparation to construction, from the thinkers to the doers. You notice that, it's a completely different type of person.'So before a shovel can be put in the ground, there is a lot of talking to involved municipalities, water boards and companies. 'Permits are needed for everything and these can differ from one municipality to another. In the municipality of The Hague, for instance, trees can only be cut down before 15 March because of the breeding season. It was exciting to still get a felling permit in time.'Op tracékaarten staan veel gele U-tekens. Dit kunnen expansielopen zijn, zoals hier, of obstakels. Foto: WarmtelinQLaying pipelinesThere are four techniques for laying a pipeline in the ground, says Gombault (see box Digging, pressing, drilling and ploughing). If there is enough space, open excavation is chosen. 'This is quite simple: we put sheet pile walls in the ground, take out the sand, lay down the pipe pieces, weld everything together and apply the insulation. Then we test whether the cathodic protection between two measuring points works.' That is a conductive wire incorporated into the insulation and running along the length of the pipe. This is a permanent check: if there is a leak, the voltage changes and that is the signal that something is wrong. Above ground, the measurement points can be identified by yellow posts placed every four hundred metres along the route.There is not always room for open excavation, especially in cities or around (rail) roads. In that case, drilling is a solution. For horizontal directional drilling, WarmtelinQ drills at an angle under the site. 'Then the hole has to be reamed. We attach a block to the drill pipe and we pull that so-called reamer back through the borehole. We do this several times in a row, until the hole has the diameter of the pipe.'BetoniteThe borehole is filled with bentonite, a kind of liquid clay, so that it does not collapse and the heat pipe can later pass smoothly through it. Before that, the pipe is ready to be welded together above ground, which requires a lot of space.'This is where we are going to plough in the heat pipe.' Gombault points out on the map a stretch of route with lots of meadows. This is a fairly new technique that is especially suitable for soft soils. 'We then forcefully pull a pipe of, say, four hundred metres long into the ground with a plough and a winch. But because our pipes are insulated, the upward pressure in peatland becomes too great and the pipe may float. For this, we have devised folding anchors on long rods. These are pushed 15 metres into the ground down to the sand layer.'Gombault demonstrates in the visitors' area how the anchor opens up when the rod is pulled up slightly for a moment.Digging, pressing, drilling and ploughingFour methods of bringing pipes into the ground:Open excavationFor hot water supply and return pipes, a trench about three metres wide is dug in the ground and lined with sheet piling. The pipe sections are welded together in the trench, after which the trench is closed again. This requires a lot of space.Ploughing in A technique where the pipe is ploughed directly into the ground is suitable for softer soils and where there are few buildings. This is a relatively quick and easy method. This also requires the pipeline to be completely above ground level. To prevent the ploughed-in pipes from rising up when they are empty, they are secured with folding anchors.Closed front drillingClosed front drilling is suitable for passing under densely populated areas, roundabouts or roads. The drill head with a piece of pipe behind it is pushed from one shaft, a demarcated space in the ground, to the other shaft. Each time, a new piece of pipe is welded to the last one, so the pipe is pushed further bit by bit. This creates a long pipe from start point to end point.Horizontal directional drillingThis technique is used when the pipeline passes under water, highways or railways. However, there must be sufficient space to prepare the pipeline in its entirety above the ground. The drill head moves using GPS, from starting point to end point. Behind the drill head are hollow tubes for supplying bentonite, liquid clay that fills the borehole so that it does not collapse. At the end point, the drill head is replaced by a reamer that is pulled back through the borehole. This is repeated until the hole is just slightly larger than the heat pipe to be inserted, so that retraction is smooth thereafter.De leidingstukken worden met de hand aan elkaar gelast. Daarna wordt er een ‘mof’ overheen geschoven, gevuld met isolatieschuim, die voorkomt dat water de leiding in loopt. Foto: WarmtelinQ/ Vincent BaslerLongest boreNear Leiden is a stretch of railway line that is one of the biggest challenges for Gombault at the moment. Before a shovel can go into the ground, archaeological and also explosives research had to be carried out. 'Near a stream, right where the pipeline comes out of the ground, flints and arrowheads were found in archaeological test trenches. That means Stone Age and therefore more archaeological research. Then a decision has to be made: to excavate or not? And if so, how long will we take?'The longest drilling to date is also planned on this stretch, no less than one and a half kilometres. The intention was to prepare the heat pipe in its entirety in a bend on the adjacent piece of land. 'But the contractor did not find that convenient. Because we are not allowed to block shipping, we have to lift the long pipe nine metres high and that becomes dangerous with a bend. Now we lay it ready on the other side in two parts. Then, when retracting, we only have to weld once more. It will also be a special bore: we will drill from two sides.'Turn overGasunie is used to pulling a pipeline through meadows from A to B, Gombault explains. More than half of the route goes through the city, which presents very different challenges. 'For the stretch near Ypenburg, for example, I have to deal with 15 different companies.' This is one of the other big challenges. There is an old sewer that could subside if sheet piling is removed, but a zero measurement is not possible because there is too much pfas in the ground, the legacy of a former foam factory. 'But the biggest problem was the drinking water pipe that runs there. The drinking water company was afraid that our supply pipe would increase the temperature of the water pipe and thus the risk of legionella. The solution now is that we will reverse the supply and return pipes. This part of the route will be chopped into seven pieces, so those businesses will be inconvenienced by nearby works for longer.'So each piece has its own problems, every 10 metres you encounter things you hadn't thought of beforehand.' And here, Gombault is not talking about trees or what you encounter in the ground in terms of animals and micro-life, but about pipes, cables, sewers and other drilling. 'It remains a surprise. There is a soil map, but it has to be filled in properly. We have already torn up the first cables. Those were far too close below ground level.'Eind 2023 werd de eerste warmwaterleiding van WarmtelinQ van de Middachtenweg in Den Haag doorgetrokken naar de Moerweg via een horizontaal gestuurde boring. Foto: WarmtelinQ/ Ward OranjeCounterbudgetGombault proudly shows the newly installed large planning board full of coloured stickers. It hangs in the area of the document controllers, which ensure that all paperwork is in the right place with the right status. 'This way I keep the state of affairs clear. If we want to start an open excavation, the things on these placards have to be done at this time. Otherwise, everything stops. That way I am constantly switching gears.'WarmtelinQ is not a cheap project, but various studies show that using waste heat is the most advantageous option in terms of social costs andCO2 reduction. Moreover, it is locally produced, has a high security of supply and helps solve grid congestion. We are talking about an investment totalling 1.111 billion, we have to make do with that, says Gombault. 'That is why we record everything to prove that we are doing everything we can to handle public money carefully. We also have a counter-budgeter specifically for this purpose. If a contractor says it will cost a hundred thousand euros, he will calculate whether that is really the case.'Heat enoughLeiden is the furthest point for WarmtelinQ for now. In Delft, however, a pumping station is already ready. 'We don't need that for now to absorb pressure losses. But the moment the heat demand increases or we are going to connect Delft or the Westland, we will,' says De Boer, who is also responsible for the realisation of the WOS in Ypenburg, which will be connected to the Rijswijk-Leiden line.In any case, heat from the port is plentiful. 'We now get residual heat from AVR waste incineration. There is enough residual heat available to continue supplying WarmtelinQ in addition to Rotterdam. After all, we always have waste,' says De Boer. 'In doing so, we can also link other heat suppliers to our network, for example additional sources from the port of Rotterdam or a geothermal company here in the Westland.'

Heat from Rotterdam

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Heat from Rotterdam

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